U.S. GOVERNMENT PRINTING OFFICE

68–497 WASHINGTON : 2011

112th Congress, 1st Session – – – – – – – – – – – – – House Document 112–43 

RECOMMENDATIONS FOR THE IMPLEMENTATION OF 

FOUR PROJECTS 

COMMUNICATION 

FROM

THE ASSISTANT SECRETARY OF THE ARMY, 

CIVIL WORKS, THE DEPARTMENT OF DEFENSE 

TRANSMITTING

RECOMMENDATIONS FOR THE IMPLEMENTATION OF FOUR 

PROJECTS BY THE SECRETARY OF THE ARMY 

VOLUME III OF VI 

JULY 12, 2011.—Referred to the Committee on Transportation and 

Infrastructure and ordered to be printed 

2:43 Sep 29 2011 Jkt 068497 PO 00000 Frm 00003 Fmt 4012 Sfmt 4012 E:\HR\OC\HD043V3 XXX HD043V3

LOUISIANA COASTAL AREA

ECOSYSTEM RESTORATION PROJECTS STUDY

Volume III of IV

Final Integrated Feasibility Study and Environmental Impact Statement

for the

Convey Atchafalaya River Water to Northern Terrebonne Marshes

And Multipurpose Operation of Houma Navigation Lock

Lafourche, Terrebonne, St. Mary Parish, Louisiana

September, 2010

U.S Army Corps of Engineers

New Orleans District

Coastal Protection and

Restoration Authority

(1)
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LOUISIANA COASTAL AREA

ECOSYSTEM RESTORATION PROJECTS STUDY

Volume III of IV

Final Integrated Feasibility Study and Environmental Impact Statement

for the

Convey Atchafalaya River Water to Northern Terrebonne Marshes

And Multipurpose Operation of Houma Navigation Lock

Lafourche, Terrebonne, St. Mary Parish, Louisiana

The responsible lead Federal agency for this study is the U. S. Army Corps of

Engineers- Mississippi Valley, New Orleans District (CEMVN). The non-Federal

sponsor for the study is Coastal Protection and Restoration Authority (CPRA).

This report is a combined feasibility report and environmental impact statement

complying with requirements of the U.S. Army Corps of Engineers (USACE) and

the Council of Environmental Quality (CEQ), and is intended to reduce duplication

and paperwork. An asterisk (*) in the table of contents notes paragraphs that are

required for National Environmental Policy Act (NEPA) compliance.

September 2010

U.S Army Corps of Engineers

New Orleans District

Coastal Protection and

Restoration Authority

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This report contains six volumes.

You are at Volume III which is the project-specific analysis for the

Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

the Houma Navigation Lock.

Volume III: Convey Atchafalaya River Water to Northern Terrebonne Marshes and

Multipurpose Operation of the Houma Navigation Lock.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010

ABSTRACT Volume III – Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

Final Integrated Feasibility Study and Environmental Impact Statement

for the

Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

LEAD AGENCY: U.S. Army Corps of Engineers – Mississippi Valley Division, New Orleans

District

ABSTRACT:

This report is an integrated feasibility study and environmental impact statement (EIS) conducted

for the Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock projects. This report fulfills the reporting requirement to

Congress of Section 7006(e)(3) which directs the Secretary of the Army to submit feasibility

reports on the six projects included in that section by December 31, 2008 and authorizes

implementation of the projects provided a favorable Chief of Engineers’ Report is completed no

later than December 31, 2010.

A -1

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010

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Executive Summary Volume III – Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

Final EIS WRDA 2007 Section 7006(e)(3) September 2010

ES-1

EXECUTIVE SUMMARY

ES 1 Summary Introduction and Study Information

Title VII of the Water Resources Development Act (WRDA) 2007 authorizes the

Louisiana Coastal Area (LCA) ecosystem restoration program. Included within that

authority are requirements for comprehensive coastal restoration planning, program

governance, a Science and Technology Program, a program for the beneficial use of

dredged material, feasibility studies for restoration plans, project modification

investigations, and restoration project construction, in addition to other program

elements. This authorization was recommended by the Chief of Engineers’ Report, dated

January 31, 2005. Under the 2007 WRDA Section 7006, the LCA program has authority

for feasibility-level reports of six near-term critical restoration features.

In November 2008, the U.S. Army Corps of Engineers (USACE) and the State of

Louisiana represented through the Coastal Protection and Restoration Authority (CPRA),

executed a single Feasibility Cost-Share Agreement (FCSA) covering six Louisiana

Coastal Area (LCA) near-term plan elements listed in Section 7006(e) of the Water

Resources Development Act, 2007. The six features will each go through a separate

feasibility analysis and environmental compliance review culminating in a single master

feasibility document. The cost-share during this feasibility phase is 50% Federal and

50% Non-Federal in total. However, the individual elements have been divided so that

each entity has lead responsibility for preparing three of the six report components. This

means that at the end of the feasibility phase the total cost will be shared on a 50/50 basis.

Yet for work on each individual element during the feasibility phase the ratio of funds

expended by either the Federal or non-Federal sponsor will be higher depending upon

their level of responsibility. Although three of the projects will be lead by state teams,

each individual feasibility component will be conducted and written to meet USACE

planning and technical standards for a feasibility level document.

ES 2 Need for, and Objectives of Action *

The purpose of the proposed action is to reduce the current trend of marsh degradation in

the project area resulting from subsidence, sea level rise, erosion, saltwater intrusion, and

lack of sediment and nutrient deposition. The project proposes to accomplish this by

utilizing fresh water and nutrients from the Atchafalaya River and the Gulf Intracoastal

Waterway (GIWW).

The LCA-ARTM Study Area comprises approximately 1100 square miles (~700,000

acres) in Southern Louisiana in the vicinity of the City of Houma and Terrebonne Parish.

The LCA-ARTM study area fits into the Louisiana Coastal Area Ecosystem Restoration

Study (LCA Study) Area, which has been identified as the Louisiana coastal area from

Mississippi to Texas. The proposed LCA-ARTM project is located in the Deltaic Plain

within Subprovince 3, one of the four Subprovinces identified in the LCA Study Area.

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ES-2

The overall study area is bound to the west by the Lower Atchafalaya River. The study

area is bound to the east by the Bayou Lafourche ridge. The study area is bound to the

north by the Bayou Black ridge, from the Lower Atchafalaya River to the City of Houma,

and by the Gulf Intracoastal Waterway from the City of Houma to the Bayou Lafourche

ridge. The southern boundary of the project was based on a delineation conducted in

2007 of coastal Louisiana vegetation types.

The natural processes of subsidence, habitat switching, and erosion, combined with

human activities, have caused significant adverse impacts to the Northern Terrebonne

Marshes, including accelerated wetland loss and ecosystem degradation.

Wetlands in the project area are deteriorating for several reasons: 1) subsidence and sea

level rise, 2) lack of sediment and nutrient deposition, 3) erosion via tidal exchange, 4)

channelization, and 5) saltwater intrusion. These activities have resulted in the loss of

several thousand acres of solid, vegetated marsh. Deterioration will continue unless

preventative measures are taken. With continued deterioration of the marshes, the area

landward will be more prone to flood during storm surges and hurricanes, as marshes

serve as partial flood barriers. Additionally, the marshes of the study area represent an

ecosystem of national importance from an environmental standpoint.

In the absence of supplemental freshwater from the Atchafalaya River, subsidence, sealevel rise, wave erosion, and saltwater intrusion will continue to be problems. Protection

and enhancement of this area are dependent on providing a hydrologic regime that

minimizes the physiological stress to wetland vegetation from saltwater intrusion and

tidal energy and is conducive to the retention of locally provided freshwater and

sediments. Several channels have been dredged which cut through the natural ridges,

increasing both drainage and tidal exchange in the project area, exposing the soil to

erosive forces.

Major navigation channels in the subprovince are the Atchafalaya River, Wax Lake

Outlet, Houma Navigation Canal, GIWW, and Lower Atchafalaya River (south of

Morgan City). Each of these navigation channels introduces and/or compounds marine

influences in many of the interior coastal wetlands and water bodies within the

subprovince. Without action, the freshwater, intermediate, and brackish marshes in the

northern and eastern areas of Terrebonne Basin would continue to deteriorate and

disappear due to the combined effects of subsidence and sea level rise, saltwater

intrusion, and a lack of riverine influence. The flotant marshes within the Penchant

Basin, located in northwest Terrebonne Basin, would continue to deteriorate due to

excessive backwater flooding events from the Atchafalaya River. The marshes in the

southern and eastern portions of the study area would continue to deteriorate due to

saltwater intrusion and a lack of riverine influence.

• Goals :

Reduce the current trend of degradation of the Terrebonne marshes, so as to

contribute towards achieving and sustaining a coastal ecosystem that can support and

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ES-3

protect the environment, economy, and culture of southern Louisiana and thus the

Nation.

• Objectives:

The objective of the project is to provide additional freshwater, nutrients, and fine

sediment to the area. The introduction of additional freshwater could facilitate

organic sediment deposition, improve biological productivity, and prevent further

deterioration of the marshes. Specific project objectives include, but are not limited

to the following and are applicable to all three sub-unit areas:

• Prevent, reduce, and/or reverse future wetland loss

• Achieve and maintain characteristics of sustainable marsh hydrology

• Reduce salinity levels in project area

• Increase sediment and nutrient load to surrounding wetlands

• Increase residence time of fresh water

• Sustain productive fish and wildlife habitat

ES 3 Alternatives

Alternatives 2 – 8 incorporate various combinations of 61 measures. Modification of the

proposed operation of the HNC (Houma Navigation Canal) Lock complex is included in

all action alternatives.

No Action. This alternative includes no measures from this project. The future condition

will include sea level rise, subsidence, and other projects that are under construction or

are likely to be constructed. This alternative includes operation of the HNC lock

complex under the Morganza to the Gulf operations plan.

Alternative 2 redistributes existing freshwater to benefit Terrebonne marshes using a

variety of measures. To achieve this, GIWW constrictions would be eliminated.

Additionally, the following measures to restrict, increase, and control water are proposed

for each of the three subunits. In the West – Bayou Penchant Area, dredging, bank

protection, a sediment plug, and a weir will be utilized. In the Central – Lake Boudreaux

Area, culverts, levees, dredging, marsh terraces and berms, sediment plugs, modified

operation of the future HNC lock complex, and a large sluice gated box culvert are

proposed. In the East – Grand Bayou Area, culverts, dredging, gaps in canal spoil banks,

marsh berms, sediment plugs, and removal of a weir and soil plug are proposed.

Alternative 3 will increase Atchafalaya River inflows and redistribute existing and

increased flows of freshwater. Alternative 3 includes all the measures in Alternative 2

and two additional. The additional measures are in the West – Bayou Penchant Area. To

increase flows from the Atchafalaya River, water will be moved from Bayou Shaffer to

the Avoca Island Cutoff/Bayou Chene. This will be accomplished by creating an opening

through the Avoca Island levee and installing a large gated diversion structure (WS4) in

the opening. The remaining measure (WO2) would place stone along the shore of Bayou

Chene and Avoca Island Cutoff to protect from increased flows.

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ES-4

Alternative 4 will increase freshwater flows from east of the project area and redistribute

existing and increased flows of freshwater. Alternative 4 includes all but one of the

measures in Alternative 2, and has two additional measures in the East – Grand Bayou

Area. In Alternative 2, a new Hwy. 24 bridge with Obermeyer gates between the piers

(EC5) is proposed to connect the GIWW to Grand Bayou. In Alternative 4, this measure

is replaced by a pump station (ES2). The pump station would increase freshwater

delivery to the Grand Bayou watershed but not the other subunits. The second new

measure is a soil plug (EP8) in Bayou L’eau Bleu. Bayou L’eau Bleu connects the canal

receiving the pump station outflow to the GIWW. The pump station is pumping water

from the GIWW, thus the soil plug is necessary to prevent recirculation of water.

Alternative 5 will increase flows from the east and west and redistribute existing and

increased flows of freshwater. This alternative is a combination of Alternatives 3 and 4.

The only measure in Alternative 3 not within this alternative is the Hwy. 24 bridge with

Obermeyer gates (EC5), which is replaced by a pump station (ES2), as in Alternative 4.

Alternative 6 will increase Atchafalaya River inflows and improve the passage of

freshwater through the GIWW while slowing water passage to the gulf through the HNC.

Alternative 6 differs from Alternative 3 in that Alternative 6 only includes water

management measures along the GIWW. The measures to increase Atchafalaya River

inflows are the same as Alternative 3. A large gated diversion structure (WS4) would be

placed in the new opening created in the Avoca Island levee. Shoreline protection would

be placed (WO2) in Bayou Chene and Avoca Island Cutoff. To improve freshwater

flows through the GIWW to Grand Bayou, the following measures from Alternative 2 are

proposed. In East – Grand Bayou Area, dredging is proposed to connect Grand Bayou to

the GIWW (ED5) and enlarge Grand Bayou (ED3). Where ED5 goes through Hwy. 24, a

new bridge with Obermeyer gates between the piers (EC5) is proposed. In the Central –

Lake Boudreaux Area, the GIWW is constricted as it passes under Hwy. 24. The Hwy.

24 bridge columns do not allow for channel enlargement. Therefore, dredging a new

secondary channel with two culverts, one under each Hwy. 24 bridge, is proposed.

Modifying the operation of the HNC Lock Complex is also included in this alternative.

Alternative 7 will slow the movement of freshwater to the Gulf of Mexico and thus put

additional freshwater onto northern Terrebonne marshes. The one measure in this

alternative is modified operation of the proposed HNC Lock Complex (CL1). The HNC

Lock Complex is part of the proposed U.S. Army Corps of Engineers Morganza to the

Gulf project for flood risk management. The Lock Complex includes a set of navigable

sector gates. Under normal operation, the navigable sector gates would remain open with

unrestricted vehicle passage and closed during storm events and when the Atchafalaya

River is low. This alternative proposes to keep the sector gates closed more frequently to

hold water back thus moving freshwater onto northern marshes. When the sector gates

are closed boat traffic would travel through the lock chambers. As part of this

alternative, an industry traffic management plan would be developed for vessels

exceeding the lock size that will require the sector gates to be opened.

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ES-5

Alternative 8 redistributes existing freshwater within the study area to benefit the eastern

and central Terrebonne marshes using a variety of measures in an effort to focus

freshwater distribution to the most critical areas of marsh decline in the study area. This

alternative represents an increment between Alternative 7 and Alternative 2 and contains

many of the features of Alternative 2. In the Central – Lake Boudreaux Area, culverts,

levees, dredging, sediment plugs, modified operation of the future HNC lock complex,

and a large sluice gated box culvert are proposed. In the East – Grand Bayou Area,

culverts, dredging, gaps in canal spoil banks, sediment plugs, and removal of a weir and

soil plug are proposed.

ES 4 Affected Environment

The overall study area is located mostly in Terrebonne Parish in southeast Louisiana at

the northern edge of the Gulf of Mexico and encompasses approximately 1,100 square

miles (700,000 acres). The study area is approximately 55 miles wide from west to east

and averages 20 miles across from the north to south boundaries. The study area lies at

the southern end of the Terrebonne Basin and contains a complex of habitat types,

including natural levees, lakes, swamps, marshes, and bayous formed from sediments of

abandoned Mississippi River deltas. Elevations in the study area vary. Near Houma, the

largest city in the area, the elevation is approximately 10 feet National Geodetic Vertical

Datum (NGVD). The elevation along the bayou ridges is 4-5 feet NGVD and less than 1

foot NGVD along the southern portion near the Gulf of Mexico. Degradation of

emergent marsh habitat is concentrated in the southern and eastern portions of the study

area. Land loss analysis conducted for the project predicted the loss of approximately

102,000 acres (18 percent) of the remaining vegetated wetlands in the study area over the

50-year period of analysis.

ES 5 Environmental Consequences

Implementation of the Recommended Plan would result in increased freshwater inputs

and associated nutrients in the study area. Improved distribution of freshwater and

nutrients would enhance vegetative productivity and optimize conditions for maintenance

of all vegetative habitats, benefitting the extensive fish and wildlife resources of the area.

Increased freshwater flows would result in decreased salinity levels throughout much of

the project area. Construction of project features would result in 148 acres of swamp,

343 acres of fresh marsh, 248 acres of intermediate marsh, and 182 acres of brackish

marsh being directly converted to open water. Alternative 2 would also result in 23 acres

of swamp being converted to upland (levee). Overall, implementation of Alternative 2

would result in the generation of 3,220 Average Annual Habitat Units over the No Action

Alternative and would result in a reduction in loss of emergent marsh habitat of 9,655

acres over the 50-year period of analysis. Navigation on the Houma Navigation Canal

would be negatively impacted by the modified operation of the lock complex. Stage

increases of up to 0.2 feet could be seen in the western portions of the study area. Stage

increases of up to 0.3 feet could be seen in the central portions of the study area. Stage

increases of up to 0.1 feet could be seen in the eastern portions of the study area. Stage

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ES-6

decreases of up to 0.2 feet could be seen on the GIWW at certain times of year.

Implementation of Alternative 2 would require the relocation of 13 residential structures.

ES 6 Public Involvement

The National Environmental Policy Act provides for an early and open public process for

determining the scope of issues, resources, impacts, and alternatives to be addressed in

the draft environmental impact statement. A scoping meeting announcement requesting

comments regarding the scope of the Convey Atchafalaya River Water to Northern

Terrebonne Marshes Study was sent to Federal, state, and local agencies and interested

groups and individuals on January 7, 2009. Public scoping meetings were held in Houma

and Morgan City on February 3 and 4, 2009, respectively. The draft feasibility

study/environmental impact statement was released to the public for a 45-day public

review period from May 21, 2010 to July 5, 2010. During this public review period

public meetings were held in Houma and Morgan City on June 2, 2010 and June 17,

2010, respectively.

ES 7 Coordination and Compliance

Coordination and planning of the ARTM project has been conducted in compliance with

various environmental laws, regulations, executive orders, policies, rules, and guidance

including USACE Principles and Guidelines, U.S. Fish and Wildlife Coordination Act,

Clean Water Act, Rivers and Harbors Act, Coastal Zone Management Act, Endangered

Species Act, Magnuson-Stevens Fishery Conservation and Management Act, Clean Air

Act, National Historic Preservation Act, and others.

ES 8 Areas of Controversy and Unresolved Issues

A potential area of controversy is the implementation of the Houma Navigation Lock

construction under a separate authority other than Louisiana Coastal Area.

The recommended plan relies on the operation of the Houma Navigation Canal Lock for

environmental purposes after 2025. The HNC lock complex is a feature of Morganza to

the Gulf of Mexico Hurricane Protection Project. The LCA-ARTM project proposes the

modification of the operational plan for the lock complex structure authorized under

Morganza to the Gulf, in order to maximize potential environmental benefits, both in

terms of avoiding saltwater intrusion and optimizing flow distribution. The proposed

action with a constructed lock complex (which comprises the Future-Without-Project

condition for the LCA project after 2025) is to operate it in such a way that freshwater

from the GIWW “escaping” down the Houma Navigation Canal could be redirected into

the surrounding wetlands. Coordinated adaptive management between ARTM and the

Morganza to Gulf Project will be necessary and is recommended.

The modified operation of the lock complex, however, may prove to be a challenge

because of the effort involved in opening and closing the floodgates. The lock itself will

be operated only when the floodgates are closed to reduce salinity within the channel.

Once closed, the floodgates would force water down other waterways (such as Bayou

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ES-7

Grand Caillou). Saltwater intrusion would be halted at the gate, and freshwater flows

would increase in other waterways. If the HNC Lock is not constructed by 2025, the

benefits of its operation would be lost and other benefits from ARTM from 2025 onward

could be altered. Additionally, since the operations plan for the HNC Lock Complex has

not been finalized, the FWOP condition could be modified. This could also alter the

benefits after the lock is constructed. However, Alternative 2 would likely remain the

NER Plan regardless of the timing of implementation of the HNC Lock Complex.

Relative sea level rise rates higher than the historic rate have the potential to greatly

reduce or even eliminate the benefits of this project. Intermediate RSLR would reduce

benefits by 66% and high RSLR would eliminate benefits. While the intent of EC1165-

2-211 on sea level rise was met, at this time it is impossible to determine the risk of

higher relative sea level rise rates. While this risk exists, the structures in the selected

plan were designed with adaptive management and RSLR in mind. Various operational

schemes may help to extend the benefits under higher RSLR scenarios.

The degree to which project area marshes will respond to increased freshwater inputs

associated with project features remains unresolved. Specifically, there is uncertainty in

whether or not increasing the flow of fresh water and nutrients to area marshes with little

associated sediment will result in the predicted level of prevention of marsh loss. It is

believed that increased freshwater will benefit study area marshes, but similar projects

that do not utilize sediment inputs that could be used as verification do not currently

exist. Robust monitoring and adaptive management will help to ensure project success

and identify outcomes that should realistically be expected for the project.

Fisheries access impacts on project benefits remain unresolved for some project features.

Inclusion of fisheries access impacts in the calculation of AAHUs may have resulted in

negative AAHUs for all alternatives, despite net gains in wetland acreages. Project

measures are designed to correct significant hydrologic alterations on man-made canals

which are thought to be significant causes of wetland degradation and loss and which

resulted in artificially increased fisheries access. In addition, other natural and man-made

waterways exist for fisheries access. Therefore, the decision was made to eliminate this

potential impact when calculating benefits associated with each alternative. Potential

modifications to this methodology are being investigated by USFWS in consultation with

NMFS, LDWF, and other interested natural resource agencies.

There are also unresolved issues with respect to the best design and operation of some

project features. Further modeling needs to be conducted during pre-construction

engineering and design in order to determine ideal sizes and operational scenarios of

some dredge features and water control structures that could not be fully analyzed during

the planning phase due to time constraints. Specific details on dredged material disposal

acreages and locations also need to be determined. Dredged material will be utilized for

marsh creation to the maximum extent practicable.

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ES-8

The impacts of the Deepwater Horizon oil spill on coastal Louisiana are uncertain at this

time (August 2010). The impacts of the oil spill as well as the various emergency actions

taken to address oil spill impacts (e.g., use of oil dispersants, creation of sand berms, use

of Hesco baskets, rip-rap, sheet piling and other actions) could potentially impact

USACE water resources projects and studies within the Louisiana coastal area, including

the LCA-ARTM project. Potential impacts could include factors such as changes to

existing, future-without, and future-with-project conditions, as well as increased project

costs and implementation delays. The USACE will continue to monitor and closely

coordinate with other Federal and state resource agencies and local sponsors in

determining how to best address any potential problems associated with the oil spill that

may adversely impact project implementation. Supplemental planning and

environmental documentation may be required as information becomes available. If at

any time petroleum or crude oil is discovered on project lands, all efforts will be taken to

seek clean up by the responsible parties, pursuant to the Oil Pollution Act of 1990 (33

U.S.C. 2701 et seq.).

ES 9 Conclusions and Recommendations

The Recommended Plan (RP) and National Ecosystem Restoration (NER) Plan,

Alternative 2, would create and nourish 329 acres of various types of nationally

significant wetlands, in addition to reducing the current trend of wetland degradation by

9,655 acres in the study area. Restoration of freshwater and nutrient inputs to the project

area will result in the creation and nourishment of a variety of marsh types within the

study area. This is accomplished without increasing flood risk.

Overall, Alternative 2 would reduce land loss in the study area from 101,570 acres to

91,915 acres, thus preventing the loss of 9,655 acres of marsh habitat over the 50-year

period of analysis. Alternative 2 would yield 3,220 AAHUs over the No Action

Alternative.

• The RP/NER plan includes the entire study area with the most critical need of

restoration.

• The RP/NER plan does not exceed the legislatively mandated cost level limit as

identified in WRDA 2007. The RP/NER plan meets the intent of the plan as

described in the 2004 LCA Report.

• The RP/NER plan can function as a stand-alone project with considerable

benefits.

• The RP/NER plan would provide significant environmental benefits regardless of

the implementation of the HNC Lock Complex.

The RP/NER is the plan that best meets the Louisiana Coastal Area goals and objectives

as well as those identified for the study area in partnership with the State of Louisiana.

The RP/NER is the plan that best meets the P&G’s four criteria of completeness,

effectiveness, efficiency, and acceptability, as well as the Environmental Operating

Principles of environmental sustainability, interdependence, balance and synergy,

accountability, knowledge, respect, and assessing and mitigating cumulative impacts.

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ES-9

The RP/NER Plan meets the current scope and cost authority as per Section 7006 (e) (3)

of WRDA 2007 or Section 902 of WRDA 1986.

The District Commander has considered all the significant aspects of this study including

the environmental, social, and economic effects, the engineering feasibility, and the

comments received from other resource agencies, the Non-Federal Sponsors, and the

public and has determined that the recommended plan presented in this report is in the

overall public interest and a justified expenditure of Federal funds. As a comprehensive

approach to restore and maintain ecological integrity, including habitats, communities,

and populations of native species, and the processes that sustain them by reducing the

trend of degradation and deterioration to the area between Bayou Lafourche and the

Atchafalaya River, the District Commander recommends the construction of Alternative

2. The interagency team recommended Alternative Plan 2 (RP/NER) as the

Recommended plan (RP). Alternative 2 (RP/NER) is also a standalone project with

significant environmental benefits and meets most of the study objectives. In cooperation

with the USFWS, NOAA, and the State of Louisiana, the Corps has planned and would

design a project that serves the needs of the nation.

The total cost for the project is $305,500,000.00 inclusive of associated investigation,

environmental, engineering and design, construction, supervision and administration, and

contingency costs. The operations and maintenance of this project may be assumed by

the State of Louisiana as the non-Federal sponsor. The project is funded 65% by the

Federal Government and 35% by the non-Federal sponsor.

The recommendation contained herein reflects the information available at this time,

October 2010 price levels, and current Departmental Policies governing the formulation

of individual projects. They do not reflect program and budgeting priorities inherent in

the formulation of a national civil works construction program, nor the perspective of

higher levels of review within the Executive Branch. Consequently, the recommendation

may be modified before being transmitted to the Congress as proposals for authorization

and/or implementation funding.

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Table of Contents Volume III – Convey Atchafalaya River Water to Northern Terrebonne Marshes

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TABLE OF CONTENTS

Volume III – Convey Atchafalaya River Water to Northern Terrebonne Marshes

And Multipurpose Operation of Houma Navigation Lock

Integrated Feasibility and Environmental Analysis 1

Abstract A-1

Executive Summary ES-1

TABLE OF CONTENTS................................................................................. I

FIGURES..................................................................................................XVII

TABLES .................................................................................................... XXI

1.0 STUDY INFORMATION................................................................. 1-1

1.1 STUDY AUTHORITY........................................................................................... 1-1

1.2 PURPOSE AND SCOPE ........................................................................................ 1-2

1.3 STUDY AREA .................................................................................................... 1-3

1.4 HISTORY OF INVESTIGATION............................................................................. 1-8

1.5 PRIOR REPORTS AND EXISTING PROJECTS......................................................... 1-8

1.5.1 Federal........................................................................................................ 1-11

1.5.1.1 Federal Laws and Programs ..................................................................................... 1-16

1.5.2 State............................................................................................................ 1-17

1.5.3 Local .......................................................................................................... 1-18

1.5.4 Existing and Likely Future Water Projects................................................ 1-18

1.5.4.1 Navigation Projects .................................................................................................. 1-18

1.5.4.2 Lower Atchafalaya Basin Floodway System ........................................................... 1-19

1.5.4.3 Hurricane Storm Surge Risk Reduction Projects ..................................................... 1-19

1.5.4.4 Coastal Restoration Projects..................................................................................... 1-20

1.5.5 Deepwater Horizon Oil Spill ..................................................................... 1-30

1.6 PLANNING PROCESS AND REPORT ORGANIZATION ......................................... 1-37

1.6.1 The Six Step Planning Process .................................................................. 1-37

1.6.2 Report Organization................................................................................... 1-39

1.7 USACE CAMPAIGN PLAN............................................................................... 1-40

2.0 NEED FOR AND OBJECTIVES OF ACTION............................... 2-1

2.1 NATIONAL OBJECTIVES..................................................................................... 2-1

2.2 PUBLIC CONCERNS............................................................................................ 2-1

2.3 PROBLEMS, NEEDS, AND OPPORTUNITIES ......................................................... 2-2

2.3.1 General Problem Statement ......................................................................... 2-6

2.3.2 Study Area Opportunities ............................................................................ 2-8

1 * An asterisk notes paragraphs that are required for National Environmental Policy Act (NEPA) compliance.

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2.3.3 Problems, Future Without Project Conditions, and Opportunities by Study

Area Subunit ............................................................................................................ 2-8

2.4 PLANNING OBJECTIVES................................................................................... 2-20

2.4.1 Goals .......................................................................................................... 2-20

2.4.2 Objectives .................................................................................................. 2-20

2.5 PLANNING CONSTRAINTS................................................................................ 2-20

2.5.1 Constraints ................................................................................................. 2-20

3.0 ALTERNATIVES ............................................................................. 3-1

3.1 PLAN FORMULATION RATIONALE ..................................................................... 3-1

3.1.1 Plan Formulation Rationale ......................................................................... 3-1

3.1.2 Plan Formulation Criteria ............................................................................ 3-1

3.1.2.1 Completeness ............................................................................................................. 3-1

3.1.2.2 Effectiveness .............................................................................................................. 3-1

3.1.2.3 Efficiency................................................................................................................... 3-1

3.1.2.4 Acceptability .............................................................................................................. 3-1

3.1.3 LCA ARTM Study Area Land Loss ............................................................ 3-2

3.2 MANAGEMENT MEASURES ............................................................................... 3-7

3.2.1 Development of Management Measures ..................................................... 3-7

3.2.2 Description of Management Measures ........................................................ 3-7

3.2.3 Screening / Evaluation of Alternative Plans ................................................ 3-9

3.2.4 Measures Not Carried Forward for Further Analysis ................................ 3-13

3.3 PRELIMINARY ALTERNATIVE PLANS............................................................... 3-14

3.3.1 Development of Alternative Plans............................................................. 3-14

3.3.2 Description of Alternative Plans................................................................ 3-21

3.3.2.1 No Action (Future without Project Conditions) – Strategy: No Action. .................. 3-21

3.3.2.2 Alternative 2 - Strategy: Utilize Existing Flow and Management Measures (Figure

3.3). 3-22

3.3.2.3 Alternative 3 - Strategy: Increase Atchafalaya River Flows and Utilize Management

Measures (Figure 3.4). ................................................................................................................ 3-22

3.3.2.4 Alternative 4 - Strategy: Increase Flow from East of the Study Area and Utilize

Management Measures (Figure 3.5)............................................................................................ 3-22

3.3.2.5 Alternative 5 - Strategy: Increase Flow from the East and from the Atchafalaya River

and Utilize Management Measures (Figure 3.6). ........................................................................ 3-22

3.3.2.6 Alternative 6 - Strategy: Increase Atchafalaya River Flow and Utilize Management

Measures (Figure 3.7). ................................................................................................................ 3-23

3.3.2.7 Alternative 7 - Strategy: Utilize Existing Flow and Management Measures (Figure

3.8). 3-23

3.3.2.8 Alternative 8 - Strategy: Utilize Existing Flow and Management Measures to Focus

Fresh Water Flows on the Most Critical Areas of the East and Central Study Sub Units (Figure

3.9). 3-23

3.3.3 Screening / Evaluation of Alternative Plans .............................................. 3-33

3.3.4 Alternative Plans not Carried Forward for Further Analysis..................... 3-33

3.4 FINAL ARRAY OF ALTERNATIVES (ALTERNATIVES STUDIED IN DETAIL)........ 3-33

3.5 COMPARISON OF ALTERNATIVE PLANS........................................................... 3-33

3.5.1 Incremental Cost/Cost Effectiveness Analysis Process............................. 3-33

3.5.2 Wetland Value Assessment (WVA) .......................................................... 3-33

3.5.3 Cost Estimates for Habitat Improvement Measures .................................. 3-37

3.5.4 Results of the CE/ICA Analysis ................................................................ 3-38

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3.5.5 Other Factors.............................................................................................. 3-41

3.5.5.1 Recreational Benefits ............................................................................................... 3-41

3.5.5.2 Desired Future Condition......................................................................................... 3-42

3.5.5.3 Adaptive Management ............................................................................................. 3-42

3.5.5.4 Acceptability, Completeness, Effectiveness, and Efficiency ................................... 3-42

3.5.5.5 Recommended Plan.................................................................................................. 3-43

3.6 NER PLAN ...................................................................................................... 3-43

3.6.1 Components of NER Plan.......................................................................... 3-43

3.6.2 Design, Environmental, and Construction Considerations of the NER Plan. 3-

46

3.6.3 Real Estate Requirements of the NER Plan............................................... 3-46

3.6.4 Operations and Maintenance Considerations of the NER Plan ................. 3-47

3.6.5 Monitoring Plan and Adaptive Management............................................. 3-47

3.7 LOCALLY-PREFERRED PLAN........................................................................... 3-49

3.8 ENVIRONMENTALLY PREFERABLE ALTERNATIVE........................................... 3-49

3.9 PLAN SELECTION – RECOMMENDED PLAN...................................................... 3-49

3.9.1 Effectiveness of Recommended Plan in Meeting Goals and Objectives... 3-49

3.9.2 Effectiveness of Recommended Plan in Meeting Environmental Operating

Principles................................................................................................................ 3-50

3.9.3 Compensatory Mitigation Measures.......................................................... 3-51

3.9.4 Planning in a Collaborative Environment.................................................. 3-51

3.10 RISK AND UNCERTAINTY ................................................................................ 3-51

3.10.1 Tropical Storm and Hurricane Damages.................................................... 3-51

3.10.2 Relative Sea Level Rise ............................................................................. 3-52

3.10.3 Real Estate ................................................................................................. 3-52

3.10.4 Combinations of Risks............................................................................... 3-53

3.10.5 Implementation of the Houma Navigation Canal Lock Complex ............. 3-54

3.10.6 Project Benefits.......................................................................................... 3-55

3.10.7 Future Analysis .......................................................................................... 3-56

3.11 IMPLEMENTATION REQUIREMENTS ................................................................. 3-57

3.11.1 Schedule..................................................................................................... 3-57

3.11.2 Implementation Responsibilities................................................................ 3-58

3.11.3 Cost Sharing............................................................................................... 3-61

3.11.4 Environmental Commitments .................................................................... 3-62

3.11.5 Financial Requirements ............................................................................. 3-63

3.11.5.1 Sponsorship Agreement ........................................................................................... 3-63

3.11.5.2 Financial Analysis.................................................................................................... 3-63

3.11.5.3 Local Cooperation.................................................................................................... 3-64

3.11.5.4 Project Management Plan ........................................................................................ 3-64

3.11.5.5 Procedures for Project Implementation.................................................................... 3-64

3.11.6 Views of Non-Federal Sponsor.................................................................. 3-66

4.0 AFFECTED ENVIRONMENT ........................................................ 4-1

4.1 ENVIRONMENTAL SETTING OF STUDY AREA .................................................... 4-1

4.1.1 Location ....................................................................................................... 4-1

4.1.2 Climate......................................................................................................... 4-2

4.1.3 Geomorphic and Physiographic Setting....................................................... 4-6

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4.2 SIGNIFICANT RESOURCES.................................................................................. 4-8

4.2.1 Soils and Waterbottoms ............................................................................... 4-8

4.2.1.1 Historic and Existing Conditions ............................................................................... 4-8

4.2.2 Hydrology .................................................................................................. 4-11

4.2.2.1 Flow and Water Levels ............................................................................................ 4-11

4.2.2.1.1 Historic and Existing Conditions......................................................................... 4-11

4.2.2.2 Sedimentation and Erosion ...................................................................................... 4-12

4.2.2.2.1 Historic and Existing Conditions......................................................................... 4-12

4.2.3 Water Quality and Salinity......................................................................... 4-13

4.2.3.1 Historic and Existing Conditions ............................................................................. 4-13

4.2.4 Air Quality ................................................................................................. 4-15

4.2.4.1 Historic and Existing Conditions ............................................................................. 4-15

4.2.5 Noise .......................................................................................................... 4-15

4.2.5.1 Historic and Existing Conditions ............................................................................. 4-16

4.2.6 Vegetation Resources................................................................................. 4-16

4.2.6.1 Invasive Species - Vegetation .................................................................................. 4-24

4.2.7 Wildlife and Habitat................................................................................... 4-24

4.2.7.1 Historic and Existing Conditions ............................................................................. 4-24

4.2.7.2 Invasive Species – Wildlife...................................................................................... 4-29

4.2.8 Aquatic Resources ..................................................................................... 4-32

4.2.8.1 Historic and Existing Conditions ............................................................................. 4-32

4.2.8.1.1 Plankton Resources ............................................................................................. 4-32

4.2.8.1.2 Benthic Resources ............................................................................................... 4-34

4.2.9 Fisheries ..................................................................................................... 4-34

4.2.9.1 Historic and Existing Conditions ............................................................................. 4-35

4.2.9.1.1 Finfish ................................................................................................................. 4-35

4.2.9.1.2 Shrimp ................................................................................................................. 4-39

4.2.9.1.3 Blue Crab............................................................................................................. 4-40

4.2.9.1.4 Oyster .................................................................................................................. 4-40

4.2.10 Essential Fish Habitat (EFH) ..................................................................... 4-43

4.2.10.1 Historic and Existing Conditions ............................................................................. 4-43

4.2.11 Threatened and Endangered Species ......................................................... 4-45

4.2.11.1 Historic and Existing Conditions ............................................................................. 4-45

4.2.12 Cultural and Historic Resources ................................................................ 4-50

4.2.12.1 Historic Conditions .................................................................................................. 4-51

4.2.12.2 Existing Conditions.................................................................................................. 4-52

4.2.13 Aesthetics................................................................................................... 4-53

4.2.13.1 Historic and Existing Conditions ............................................................................. 4-53

4.2.14 Recreation .................................................................................................. 4-61

4.2.14.1 Historic and Existing Conditions ............................................................................. 4-61

4.2.15 Socioeconomics and Human Resources .................................................... 4-63

4.2.15.1 Population and Housing ........................................................................................... 4-63

4.2.15.2 Employment and Income ......................................................................................... 4-65

4.2.15.3 Infrastructure............................................................................................................ 4-68

4.2.15.3.1 Business and Industry.......................................................................................... 4-68

4.2.15.3.2 Transportation ..................................................................................................... 4-68

4.2.15.3.3 Public Facilities and Services.............................................................................. 4-68

4.2.15.3.4 Tax Revenue and Property Values ...................................................................... 4-68

4.2.15.3.5 Community and Regional Growth (including Community Cohesion) ................ 4-69

4.2.15.4 Environmental Justice .............................................................................................. 4-69

4.2.15.5 Water Use and Supply.............................................................................................. 4-72

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4.2.15.6 Navigation................................................................................................................ 4-74

4.2.15.7 Land Use Socioeconomics ....................................................................................... 4-76

4.2.15.7.1 Agriculture .......................................................................................................... 4-76

4.2.15.7.2 Forestry ............................................................................................................... 4-77

4.2.15.7.3 Public Lands........................................................................................................ 4-78

4.2.15.8 Man Made Resources............................................................................................... 4-78

4.2.15.8.1 Oil Gas and Utilities ............................................................................................ 4-78

4.2.15.8.2 Flood Control and Hurricane Protection ............................................................. 4-82

4.2.15.9 Natural Resources .................................................................................................... 4-85

4.2.15.9.1 Commercial Fisheries.......................................................................................... 4-85

4.2.15.9.2 Oyster Leases ...................................................................................................... 4-86

4.2.16 Hazardous, Toxic, and Radioactive Wastes............................................... 4-87

4.2.16.1 Historic and Existing Conditions ............................................................................. 4-87

5.0 ENVIRONMENTAL CONSEQUENCES........................................ 5-1

5.1 SOILS AND WATERBOTTOMS........................................................................... 5-11

5.1.1 No Action Alternative (Future without Project Conditions)...................... 5-11

5.1.2 Alternative 2 (NER Plan and RP) .............................................................. 5-11

5.1.2.1 Direct........................................................................................................................ 5-11

5.1.2.2 Indirect ..................................................................................................................... 5-12

5.1.2.3 Cumulative............................................................................................................... 5-12

5.1.3 Alternative 3............................................................................................... 5-12

5.1.3.1 Direct........................................................................................................................ 5-12

5.1.3.2 Indirect ..................................................................................................................... 5-12

5.1.3.3 Cumulative............................................................................................................... 5-13

5.1.4 Alternative 4............................................................................................... 5-13

5.1.4.1 Direct........................................................................................................................ 5-13

5.1.4.2 Indirect ..................................................................................................................... 5-13

5.1.4.3 Cumulative............................................................................................................... 5-13

5.1.5 Alternative 5............................................................................................... 5-13

5.1.5.1 Direct........................................................................................................................ 5-13

5.1.5.2 Indirect ..................................................................................................................... 5-13

5.1.5.3 Cumulative............................................................................................................... 5-13

5.1.6 Alternative 6............................................................................................... 5-14

5.1.6.1 Direct........................................................................................................................ 5-14

5.1.6.2 Indirect ..................................................................................................................... 5-14

5.1.6.3 Cumulative............................................................................................................... 5-14

5.1.7 Alternative 7............................................................................................... 5-14

5.1.7.1 Direct........................................................................................................................ 5-14

5.1.7.2 Indirect ..................................................................................................................... 5-14

5.1.7.3 Cumulative............................................................................................................... 5-14

5.1.8 Alternative 8............................................................................................... 5-15

5.1.8.1 Direct........................................................................................................................ 5-15

5.1.8.2 Indirect ..................................................................................................................... 5-15

5.1.8.3 Cumulative............................................................................................................... 5-15

5.2 HYDROLOGY................................................................................................... 5-23

5.2.1 Flow and Water Levels .............................................................................. 5-23

5.2.1.1 No Action Alternative (Future without Project Conditions) .................................... 5-23

5.2.1.2 Alternative 2 (NER Plan and RP) ............................................................................ 5-23

5.2.1.2.1 Direct................................................................................................................... 5-23

5.2.1.2.2 Indirect ................................................................................................................ 5-24

5.2.1.2.3 Cumulative .......................................................................................................... 5-24

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5.2.1.3 Alternative 3............................................................................................................. 5-25

5.2.1.4 Alternative 4............................................................................................................. 5-25

5.2.1.5 Alternative 5............................................................................................................. 5-26

5.2.1.6 Alternative 6............................................................................................................. 5-27

5.2.1.7 Alternative 7............................................................................................................. 5-27

5.2.1.8 Alternative 8............................................................................................................. 5-28

5.2.2 Sedimentation and Erosion ........................................................................ 5-29

5.2.2.1 No Action Alternative (Future without Project Conditions) .................................... 5-29

5.2.2.2 Alternative 2 (NER Plan and RP) ............................................................................ 5-29

5.2.2.2.1 Direct................................................................................................................... 5-29

5.2.2.2.2 Indirect ................................................................................................................ 5-29

5.2.2.2.3 Cumulative .......................................................................................................... 5-30

5.2.2.3 Alternative 3............................................................................................................. 5-30

5.2.2.4 Alternative 4............................................................................................................. 5-30

5.2.2.5 Alternative 5............................................................................................................. 5-30

5.2.2.6 Alternative 6............................................................................................................. 5-30

5.2.2.7 Alternative 7............................................................................................................. 5-30

5.2.2.8 Alternative 8............................................................................................................. 5-30

5.3 WATER QUALITY AND SALINITY .................................................................... 5-31

5.3.1 No Action Alternative (Future without Project Conditions)...................... 5-31

5.3.2 Alternative 2 (NER Plan and RP) .............................................................. 5-33

5.3.2.1 Direct........................................................................................................................ 5-33

5.3.2.2 Indirect ..................................................................................................................... 5-34

5.3.2.3 Cumulative............................................................................................................... 5-34

5.3.3 Alternative 3............................................................................................... 5-35

5.3.4 Alternative 4............................................................................................... 5-35

5.3.5 Alternative 5............................................................................................... 5-35

5.3.6 Alternative 6............................................................................................... 5-36

5.3.7 Alternative 7............................................................................................... 5-36

5.3.8 Alternative 8............................................................................................... 5-36

5.4 AIR QUALITY .................................................................................................. 5-61

5.4.1 No Action Alternative (Future without Project Conditions)...................... 5-61

5.4.2 Alternative 2 (NER Plan and RP) .............................................................. 5-61

5.4.2.1 Direct........................................................................................................................ 5-61

5.4.2.2 Indirect ..................................................................................................................... 5-61

5.4.2.3 Cumulative............................................................................................................... 5-62

5.4.3 Alternative 3............................................................................................... 5-62

5.4.4 Alternative 4............................................................................................... 5-62

5.4.5 Alternative 5............................................................................................... 5-62

5.4.6 Alternative 6............................................................................................... 5-62

5.4.7 Alternative 7............................................................................................... 5-63

5.4.8 Alternative 8............................................................................................... 5-63

5.5 NOISE.............................................................................................................. 5-64

5.5.1 No Action Alternative (Future without Project Conditions)...................... 5-64

5.5.2 Alternative 2 (NER Plan and RP) .............................................................. 5-64

5.5.2.1 Direct........................................................................................................................ 5-64

5.5.2.2 Indirect ..................................................................................................................... 5-64

5.5.2.3 Cumulative............................................................................................................... 5-65

5.5.3 Alternative 3............................................................................................... 5-65

5.5.4 Alternative 4............................................................................................... 5-65

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5.5.5 Alternative 5............................................................................................... 5-65

5.5.6 Alternative 6............................................................................................... 5-65

5.5.7 Alternative 7............................................................................................... 5-66

5.5.7.1 Direct........................................................................................................................ 5-66

5.5.7.2 Indirect ..................................................................................................................... 5-66

5.5.7.3 Cumulative............................................................................................................... 5-66

5.5.8 Alternative 8............................................................................................... 5-66

5.6 VEGETATION RESOURCES ............................................................................... 5-67

5.6.1 No Action Alternative (Future without Project Conditions)...................... 5-67

5.6.2 Alternative 2 (NER Plan and RP) .............................................................. 5-74

5.6.2.1 Direct........................................................................................................................ 5-74

5.6.2.2 Indirect ..................................................................................................................... 5-74

5.6.2.3 Cumulative............................................................................................................... 5-75

5.6.3 Alternative 3............................................................................................... 5-75

5.6.3.1 Direct........................................................................................................................ 5-75

5.6.3.2 Indirect ..................................................................................................................... 5-75

5.6.3.3 Cumulative............................................................................................................... 5-75

5.6.4 Alternative 4............................................................................................... 5-76

5.6.4.1 Direct........................................................................................................................ 5-76

5.6.4.2 Indirect ..................................................................................................................... 5-76

5.6.4.3 Cumulative............................................................................................................... 5-76

5.6.5 Alternative 5............................................................................................... 5-76

5.6.5.1 Direct........................................................................................................................ 5-76

5.6.5.2 Indirect ..................................................................................................................... 5-76

5.6.5.3 Cumulative............................................................................................................... 5-76

5.6.6 Alternative 6............................................................................................... 5-76

5.6.6.1 Direct........................................................................................................................ 5-76

5.6.6.2 Indirect ..................................................................................................................... 5-77

5.6.6.3 Cumulative............................................................................................................... 5-77

5.6.7 Alternative 7............................................................................................... 5-77

5.6.7.1 Direct........................................................................................................................ 5-77

5.6.7.2 Indirect ..................................................................................................................... 5-77

5.6.7.3 Cumulative............................................................................................................... 5-77

5.6.8 Alternative 8............................................................................................... 5-77

5.6.8.1 Direct........................................................................................................................ 5-77

5.6.8.2 Indirect ..................................................................................................................... 5-77

5.6.8.3 Cumulative............................................................................................................... 5-78

5.6.9 Invasive Species - Vegetation.................................................................... 5-80

5.6.9.1 No Action Alternative (Future without Project Conditions) .................................... 5-80

5.6.9.2 Alternative 2 (NER Plan and RP) ............................................................................ 5-80

5.6.9.2.1 Direct................................................................................................................... 5-80

5.6.9.2.2 Indirect ................................................................................................................ 5-80

5.6.9.2.3 Cumulative .......................................................................................................... 5-81

5.6.9.3 Alternative 3............................................................................................................. 5-81

5.6.9.4 Alternative 4............................................................................................................. 5-81

5.6.9.5 Alternative 5............................................................................................................. 5-81

5.6.9.6 Alternative 6............................................................................................................. 5-81

5.6.9.7 Alternative 7............................................................................................................. 5-81

5.6.9.8 Alternative 8............................................................................................................. 5-81

5.7 WILDLIFE AND HABITAT................................................................................. 5-82

5.7.1 No Action Alternative (Future without Project Conditions)...................... 5-82

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5.7.2 Alternative 2 (NER Plan and RP) .............................................................. 5-83

5.7.2.1 Direct........................................................................................................................ 5-83

5.7.2.2 Indirect ..................................................................................................................... 5-84

5.7.2.3 Cumulative............................................................................................................... 5-85

5.7.3 Alternative 3............................................................................................... 5-85

5.7.3.1 Direct........................................................................................................................ 5-85

5.7.3.2 Indirect ..................................................................................................................... 5-85

5.7.3.3 Cumulative............................................................................................................... 5-85

5.7.4 Alternative 4............................................................................................... 5-85

5.7.4.1 Direct........................................................................................................................ 5-85

5.7.4.2 Indirect ..................................................................................................................... 5-85

5.7.4.3 Cumulative............................................................................................................... 5-85

5.7.5 Alternative 5............................................................................................... 5-85

5.7.5.1 Direct........................................................................................................................ 5-85

5.7.5.2 Indirect ..................................................................................................................... 5-86

5.7.5.3 Cumulative............................................................................................................... 5-86

5.7.6 Alternative 6............................................................................................... 5-86

5.7.6.1 Direct........................................................................................................................ 5-86

5.7.6.2 Indirect ..................................................................................................................... 5-86

5.7.6.3 Cumulative............................................................................................................... 5-86

5.7.7 Alternative 7............................................................................................... 5-86

5.7.7.1 Direct........................................................................................................................ 5-86

5.7.7.2 Indirect ..................................................................................................................... 5-86

5.7.7.3 Cumulative............................................................................................................... 5-86

5.7.8 Alternative 8............................................................................................... 5-87

5.7.8.1 Direct........................................................................................................................ 5-87

5.7.8.2 Indirect ..................................................................................................................... 5-87

5.7.8.3 Cumulative............................................................................................................... 5-87

5.8 AQUATIC RESOURCES ..................................................................................... 5-88

5.8.1 Plankton Resources.................................................................................... 5-88

5.8.1.1 No Action Alternative (Future without Project Conditions) .................................... 5-88

5.8.1.2 Alternative 2 (NER Plan and RP) ............................................................................ 5-88

5.8.1.2.1 Direct................................................................................................................... 5-88

5.8.1.2.2 Indirect ................................................................................................................ 5-88

5.8.1.2.3 Cumulative .......................................................................................................... 5-88

5.8.1.3 Alternative 3............................................................................................................. 5-89

5.8.1.4 Alternative 4............................................................................................................. 5-89

5.8.1.5 Alternative 5............................................................................................................. 5-89

5.8.1.6 Alternative 6............................................................................................................. 5-89

5.8.1.7 Alternative 7............................................................................................................. 5-89

5.8.1.8 Alternative 8............................................................................................................. 5-89

5.8.2 Benthic Resources...................................................................................... 5-90

5.8.2.1 No Action Alternative (Future without Project Conditions) .................................... 5-90

5.8.2.2 Alternative 2 (NER Plan and RP) ............................................................................ 5-90

5.8.2.2.1 Direct................................................................................................................... 5-90

5.8.2.2.2 Indirect ................................................................................................................ 5-90

5.8.2.2.3 Cumulative .......................................................................................................... 5-90

5.8.2.3 Alternative 3............................................................................................................. 5-90

5.8.2.4 Alternative 4............................................................................................................. 5-90

5.8.2.5 Alternative 5............................................................................................................. 5-91

5.8.2.6 Alternative 6............................................................................................................. 5-91

5.8.2.7 Alternative 7............................................................................................................. 5-91

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5.8.2.8 Alternative 8............................................................................................................. 5-91

5.9 FISHERIES ....................................................................................................... 5-92

5.9.1 No Action Alternative (Future without Project Conditions)...................... 5-92

5.9.2 Alternative 2 (NER Plan and RP) .............................................................. 5-93

5.9.2.1 Direct........................................................................................................................ 5-93

5.9.2.2 Indirect ..................................................................................................................... 5-94

5.9.2.3 Cumulative............................................................................................................... 5-95

5.9.3 Alternative 3............................................................................................. 5-101

5.9.4 Alternative 4............................................................................................. 5-101

5.9.4.1 Direct...................................................................................................................... 5-101

5.9.4.2 Indirect ................................................................................................................... 5-101

5.9.4.3 Cumulative............................................................................................................. 5-101

5.9.5 Alternative 5............................................................................................. 5-102

5.9.5.1 Direct...................................................................................................................... 5-102

5.9.5.2 Indirect ................................................................................................................... 5-102

5.9.5.3 Cumulative............................................................................................................. 5-102

5.9.6 Alternative 6............................................................................................. 5-102

5.9.6.1 Direct...................................................................................................................... 5-102

5.9.6.2 Indirect ................................................................................................................... 5-103

5.9.6.3 Cumulative............................................................................................................. 5-103

5.9.7 Alternative 7............................................................................................. 5-103

5.9.7.1 Direct...................................................................................................................... 5-103

5.9.7.2 Indirect ................................................................................................................... 5-103

5.9.7.3 Cumulative............................................................................................................. 5-103

5.9.8 Alternative 8............................................................................................. 5-103

5.9.8.1 Direct...................................................................................................................... 5-103

5.9.8.2 Indirect ................................................................................................................... 5-104

5.9.8.3 Cumulative............................................................................................................. 5-104

5.10 ESSENTIAL FISH HABITAT (EFH).................................................................. 5-105

5.10.1 No Action Alternative (Future without Project Conditions).................... 5-106

5.10.2 Alternative 2 (NER Plan and RP) ............................................................ 5-106

5.10.2.1 Direct...................................................................................................................... 5-106

5.10.2.2 Indirect ................................................................................................................... 5-107

5.10.2.3 Cumulative............................................................................................................. 5-108

5.10.3 Alternative 3............................................................................................. 5-108

5.10.3.1 Direct...................................................................................................................... 5-108

5.10.3.2 Indirect ................................................................................................................... 5-108

5.10.3.3 Cumulative............................................................................................................. 5-108

5.10.4 Alternative 4............................................................................................. 5-108

5.10.4.1 Direct...................................................................................................................... 5-108

5.10.4.2 Indirect ................................................................................................................... 5-108

5.10.4.3 Cumulative............................................................................................................. 5-109

5.10.5 Alternative 5............................................................................................. 5-109

5.10.5.1 Direct...................................................................................................................... 5-109

5.10.5.2 Indirect ................................................................................................................... 5-109

5.10.5.3 Cumulative............................................................................................................. 5-109

5.10.6 Alternative 6............................................................................................. 5-109

5.10.6.1 Direct...................................................................................................................... 5-109

5.10.6.2 Indirect ................................................................................................................... 5-109

5.10.6.3 Cumulative............................................................................................................. 5-110

5.10.7 Alternative 7............................................................................................. 5-110

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5.10.7.1 Direct...................................................................................................................... 5-110

5.10.7.2 Indirect ................................................................................................................... 5-110

5.10.7.3 Cumulative............................................................................................................. 5-110

5.10.8 Alternative 8............................................................................................. 5-110

5.10.8.1 Direct...................................................................................................................... 5-110

5.10.8.2 Indirect ................................................................................................................... 5-111

5.10.8.3 Cumulative............................................................................................................. 5-111

5.11 THREATENED AND ENDANGERED SPECIES .................................................... 5-112

5.11.1 No Action Alternative (Future without Project Conditions).................... 5-112

5.11.2 Alternative 2 (NER Plan and RP) ............................................................ 5-112

5.11.2.1 Direct...................................................................................................................... 5-112

5.11.2.2 Indirect ................................................................................................................... 5-114

5.11.2.3 Cumulative............................................................................................................. 5-114

5.11.3 Alternative 3............................................................................................. 5-114

5.11.4 Alternative 4............................................................................................. 5-114

5.11.5 Alternative 5............................................................................................. 5-114

5.11.6 Alternative 6............................................................................................. 5-114

5.11.7 Alternative 7............................................................................................. 5-114

5.11.8 Alternative 8............................................................................................. 5-114

5.12 CULTURAL AND HISTORIC RESOURCES......................................................... 5-115

5.12.1 No Action Alternative (Future without Project Conditions).................... 5-119

5.12.1.1 Direct...................................................................................................................... 5-119

5.12.1.2 Indirect ................................................................................................................... 5-119

5.12.1.3 Cumulative............................................................................................................. 5-119

5.12.2 Alternative 2 (NER Plan and RP) ............................................................ 5-119

5.12.2.1 Direct...................................................................................................................... 5-119

5.12.2.2 Indirect ................................................................................................................... 5-119

5.12.2.3 Cumulative............................................................................................................. 5-119

5.12.3 Alternative 3............................................................................................. 5-119

5.12.3.1 Direct...................................................................................................................... 5-119

5.12.3.2 Indirect ................................................................................................................... 5-120

5.12.3.3 Cumulative............................................................................................................. 5-120

5.12.4 Alternative 4............................................................................................. 5-120

5.12.4.1 Direct...................................................................................................................... 5-120

5.12.4.2 Indirect ................................................................................................................... 5-120

5.12.4.3 Cumulative............................................................................................................. 5-120

5.12.5 Alternative 5............................................................................................. 5-120

5.12.5.1 Direct...................................................................................................................... 5-120

5.12.5.2 Indirect ................................................................................................................... 5-120

5.12.5.3 Cumulative............................................................................................................. 5-121

5.12.6 Alt Alternative 6 ...................................................................................... 5-121

5.12.6.1 Direct...................................................................................................................... 5-121

5.12.6.2 Indirect ................................................................................................................... 5-121

5.12.6.3 Cumulative............................................................................................................. 5-121

5.12.7 Alternative 7............................................................................................. 5-121

5.12.7.1 Direct...................................................................................................................... 5-121

5.12.7.2 Indirect ................................................................................................................... 5-121

5.12.7.3 Cumulative............................................................................................................. 5-121

5.12.8 Alternative 8............................................................................................. 5-121

5.12.8.1 Direct...................................................................................................................... 5-121

5.12.8.2 Indirect ................................................................................................................... 5-122

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5.12.8.3 Cumulative............................................................................................................. 5-122

5.13 AESTHETICS .................................................................................................. 5-123

5.13.1 No Action Alternative (Future without Project Conditions).................... 5-123

5.13.2 Alternative 2 (NER Plan and RP) ............................................................ 5-123

5.13.2.1 Direct...................................................................................................................... 5-123

5.13.2.2 Indirect ................................................................................................................... 5-123

5.13.2.3 Cumulative............................................................................................................. 5-123

5.13.3 Alternative 3............................................................................................. 5-124

5.13.4 Alternative 4............................................................................................. 5-124

5.13.4.1 Direct...................................................................................................................... 5-124

5.13.4.2 Indirect ................................................................................................................... 5-124

5.13.4.3 Cumulative............................................................................................................. 5-124

5.13.5 Alternative 5............................................................................................. 5-124

5.13.6 Alternative 6............................................................................................. 5-124

5.13.7 Alternative 7............................................................................................. 5-124

5.13.8 Alternative 8............................................................................................. 5-124

5.14 RECREATION................................................................................................. 5-125

5.14.1 No Action Alternative (Future without Project Conditions).................... 5-125

5.14.2 Alternative 2 (NER Plan and RP) ............................................................ 5-126

5.14.2.1 Direct...................................................................................................................... 5-126

5.14.2.2 Indirect ................................................................................................................... 5-126

5.14.2.3 Cumulative............................................................................................................. 5-127

5.14.3 Alternative 3............................................................................................. 5-128

5.14.3.1 Direct...................................................................................................................... 5-128

5.14.3.2 Indirect ................................................................................................................... 5-128

5.14.3.3 Cumulative............................................................................................................. 5-128

5.14.4 Alternative 4............................................................................................. 5-128

5.14.4.1 Direct...................................................................................................................... 5-128

5.14.4.2 Indirect ................................................................................................................... 5-128

5.14.4.3 Cumulative............................................................................................................. 5-129

5.14.5 Alternative 5............................................................................................. 5-129

5.14.5.1 Direct...................................................................................................................... 5-129

5.14.5.2 Indirect ................................................................................................................... 5-129

5.14.5.3 Cumulative............................................................................................................. 5-129

5.14.6 Alternative 6............................................................................................. 5-129

5.14.6.1 Direct...................................................................................................................... 5-129

5.14.6.2 Indirect ................................................................................................................... 5-129

5.14.6.3 Cumulative............................................................................................................. 5-130

5.14.7 Alternative 7............................................................................................. 5-130

5.14.7.1 Direct...................................................................................................................... 5-130

5.14.7.2 Indirect ................................................................................................................... 5-130

5.14.7.3 Cumulative............................................................................................................. 5-131

5.14.8 Alternative 8............................................................................................. 5-131

5.14.8.1 Direct...................................................................................................................... 5-131

5.14.8.2 Indirect ................................................................................................................... 5-131

5.14.8.3 Cumulative............................................................................................................. 5-131

5.15 SOCIOECONOMICS AND HUMAN RESOURCES ................................................ 5-132

5.15.1 Displacement of Population and Housing................................................ 5-132

5.15.1.1 No Action Alternative (Future without Project Conditions) .................................. 5-132

5.15.1.2 Alternative 2 (NER Plan and RP) .......................................................................... 5-132

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5.15.1.3 Alternative 3........................................................................................................... 5-133

5.15.1.4 Alternative 4........................................................................................................... 5-133

5.15.1.5 Alternative 5........................................................................................................... 5-133

5.15.1.6 Alternative 6........................................................................................................... 5-134

5.15.1.7 Alternative 7........................................................................................................... 5-134

5.15.1.8 Alternative 8........................................................................................................... 5-135

5.15.2 Employment and Income ......................................................................... 5-136

5.15.2.1 No Action Alternative (Future without Project Conditions) .................................. 5-136

5.15.2.2 Alternative 2 (NER Plan and RP) .......................................................................... 5-136

5.15.2.3 Alternative 3........................................................................................................... 5-136

5.15.2.4 Alternative 4........................................................................................................... 5-136

5.15.2.5 Alternative 5........................................................................................................... 5-137

5.15.2.6 Alternative 6........................................................................................................... 5-137

5.15.2.7 Alternative 7........................................................................................................... 5-137

5.15.2.8 Alternative 8........................................................................................................... 5-137

5.15.3 Infrastructure............................................................................................ 5-138

5.15.3.1 Business and Industry ............................................................................................ 5-138

5.15.3.1.1 No Action Alternative (Future without Project Conditions) ............................. 5-138

5.15.3.1.2 Alternative 2 (NER Plan and RP ....................................................................... 5-138

5.15.3.1.3 Alternative 3...................................................................................................... 5-138

5.15.3.1.4 Alternative 4...................................................................................................... 5-138

5.15.3.1.5 Alternative 5...................................................................................................... 5-138

5.15.3.1.6 Alternative 6...................................................................................................... 5-139

5.15.3.1.7 Alternative 7...................................................................................................... 5-139

5.15.3.1.8 Alternative 8...................................................................................................... 5-139

5.15.3.2 Transportation ........................................................................................................ 5-140

5.15.3.2.1 No Action Alternative (Future without Project Conditions) ............................. 5-140

5.15.3.2.2 Alternative 2 (NER Plan and RP)...................................................................... 5-140

5.15.3.2.3 Alternative 3...................................................................................................... 5-140

5.15.3.2.4 Alternative 4...................................................................................................... 5-140

5.15.3.2.5 Alternative 5...................................................................................................... 5-140

5.15.3.2.6 Alternative 6...................................................................................................... 5-141

5.15.3.2.7 Alternative 7...................................................................................................... 5-141

5.15.3.2.8 Alternative 8...................................................................................................... 5-141

5.15.3.3 Public Facilities and Services................................................................................. 5-142

5.15.3.3.1 No Action Alternative (Future without Project Conditions) ............................. 5-142

5.15.3.3.2 Alternative 2 (NER Plan and RP)) .................................................................... 5-142

5.15.3.3.3 Alternative 3...................................................................................................... 5-142

5.15.3.3.4 Alternative 4...................................................................................................... 5-142

5.15.3.3.5 Alternative 5...................................................................................................... 5-142

5.15.3.3.6 Alternative 6...................................................................................................... 5-142

5.15.3.3.7 Alternative 7...................................................................................................... 5-142

5.15.3.3.8 Alternative 8...................................................................................................... 5-142

5.15.3.4 Tax Revenue and Property Values ......................................................................... 5-143

5.15.3.4.1 No Action Alternative (Future without Project Conditions) ............................. 5-143

5.15.3.4.2 Alternative 2 (NER Plan and RP)...................................................................... 5-143

5.15.3.4.3 Alternative 3...................................................................................................... 5-143

5.15.3.4.4 Alternative 4...................................................................................................... 5-143

5.15.3.4.5 Alternative 5...................................................................................................... 5-143

5.15.3.4.6 Alternative 6...................................................................................................... 5-143

5.15.3.4.7 Alternative 7...................................................................................................... 5-144

5.15.3.4.8 Alternative 8...................................................................................................... 5-144

5.15.3.5 Community and Regional Growth (including Community Cohesion)................... 5-145

5.15.3.5.1 No Action Alternative (Future without Project Conditions) ............................. 5-145

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5.15.3.5.2 Alternative 2 (NER Plan and RP)...................................................................... 5-145

5.15.3.5.3 Alternative 3...................................................................................................... 5-145

5.15.3.5.4 Alternative 4...................................................................................................... 5-145

5.15.3.5.5 Alternative 5...................................................................................................... 5-146

5.15.3.5.6 Alternative 6...................................................................................................... 5-146

5.15.3.5.7 Alternative 7...................................................................................................... 5-146

5.15.3.5.8 Alternative 8...................................................................................................... 5-146

5.15.4 Environmental Justice.............................................................................. 5-147

5.15.4.1 No Action Alternative (Future without Project Conditions) .................................. 5-147

5.15.4.2 Alternative 2 (NER Plan and RP) .......................................................................... 5-147

5.15.4.3 Alternative 3........................................................................................................... 5-148

5.15.4.4 Alternative 4........................................................................................................... 5-148

5.15.4.5 Alternative 5........................................................................................................... 5-148

5.15.4.6 Alternative 6........................................................................................................... 5-148

5.15.4.7 Alternative 7........................................................................................................... 5-148

5.15.4.8 Alternative 8........................................................................................................... 5-148

5.15.5 Water Use and Supply ............................................................................. 5-149

5.15.5.1 No Action Alternative (Future without Project Conditions) .................................. 5-149

5.15.5.2 Alternative 2 (NER Plan and RP) .......................................................................... 5-149

5.15.5.3 Alternative 3........................................................................................................... 5-149

5.15.5.4 Alternative 4........................................................................................................... 5-150

5.15.5.5 Alternative 5........................................................................................................... 5-150

5.15.5.6 Alternative 6........................................................................................................... 5-150

5.15.5.7 Alternative 7........................................................................................................... 5-150

5.15.5.8 Alternative 8........................................................................................................... 5-150

5.15.6 Navigation................................................................................................ 5-151

5.15.6.1 No Action Alternative (Future without Project Conditions) .................................. 5-151

5.15.6.2 Alternative 2 (NER Plan and RP) .......................................................................... 5-151

5.15.6.3 Alternative 3........................................................................................................... 5-152

5.15.6.4 Alternative 4........................................................................................................... 5-153

5.15.6.5 Alternative 5........................................................................................................... 5-153

5.15.6.6 Alternative 6........................................................................................................... 5-154

5.15.6.7 Alternative 7........................................................................................................... 5-154

5.15.6.8 Alternative 8........................................................................................................... 5-155

5.15.7 Land Use and Socioeconomics ................................................................ 5-159

5.15.7.1 Agriculture ............................................................................................................. 5-159

5.15.7.1.1 No Action Alternative (Future without Project Conditions) ............................. 5-159

5.15.7.1.2 Alternative 2 (NER Plan and RP)...................................................................... 5-159

5.15.7.1.3 Alternative 3...................................................................................................... 5-159

5.15.7.1.4 Alternative 4...................................................................................................... 5-159

5.15.7.1.5 Alternative 5...................................................................................................... 5-160

5.15.7.1.6 Alternative 6...................................................................................................... 5-160

5.15.7.1.7 Alternative 7...................................................................................................... 5-160

5.15.7.1.8 Alternative 8...................................................................................................... 5-161

5.15.7.2 Forestry .................................................................................................................. 5-162

5.15.7.2.1 No Action Alternative (Future without Project Conditions) ............................. 5-162

5.15.7.2.2 Alternative 2 (NER Plan and RP)...................................................................... 5-162

5.15.7.2.3 Alternative 3...................................................................................................... 5-162

5.15.7.2.4 Alternative 4...................................................................................................... 5-162

5.15.7.2.5 Alternative 5...................................................................................................... 5-163

5.15.7.2.6 Alternative 6...................................................................................................... 5-163

5.15.7.2.7 Alternative 7...................................................................................................... 5-163

5.15.7.2.8 Alternative 8...................................................................................................... 5-164

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5.15.8 Public Lands............................................................................................. 5-165

5.15.8.1 No Action Alternative (Future without Project Conditions) .................................. 5-165

5.15.8.2 Alternative 2 (NER Plan and RP) .......................................................................... 5-165

5.15.8.3 Alternative 3........................................................................................................... 5-165

5.15.8.4 Alternative 4........................................................................................................... 5-166

5.15.8.5 Alternative 5........................................................................................................... 5-167

5.15.8.6 Alternative 6........................................................................................................... 5-167

5.15.8.7 Alternative 7........................................................................................................... 5-168

5.15.8.8 Alternative 8........................................................................................................... 5-168

5.15.9 Man Made Resources............................................................................... 5-170

5.15.9.1 Oil , Gas, and Utilities............................................................................................ 5-170

5.15.9.1.1 No Action Alternative (Future without Project Conditions) ............................. 5-170

5.15.9.1.2 Alternative 2 (NER Plan and RP)...................................................................... 5-171

5.15.9.1.3 Alternative 3...................................................................................................... 5-171

5.15.9.1.4 Alternative 4...................................................................................................... 5-172

5.15.9.1.5 Alternative 5...................................................................................................... 5-172

5.15.9.1.6 Alternative 6...................................................................................................... 5-173

5.15.9.1.7 Alternative 7...................................................................................................... 5-173

5.15.9.1.8 Alternative 8...................................................................................................... 5-173

5.15.9.2 Flood Control and Hurricane Protection ................................................................ 5-175

5.15.9.2.1 No Action Alternative (Future without Project Conditions) ............................. 5-175

5.15.9.2.2 Alternative 2 (NER Plan and RP)...................................................................... 5-175

5.15.9.2.3 Alternative 3...................................................................................................... 5-176

5.15.9.2.4 Alternative 4...................................................................................................... 5-176

5.15.9.2.5 Alternative 5...................................................................................................... 5-177

5.15.9.2.6 Alternative 6...................................................................................................... 5-178

5.15.9.2.7 Alternative 7...................................................................................................... 5-179

5.15.9.2.8 Alternative 8...................................................................................................... 5-179

5.15.10 Natural Resources ................................................................................ 5-181

5.15.10.1 Commercial Fisheries........................................................................................ 5-181

5.15.10.1.1 No Action Alternative (Future without Project Conditions) ............................. 5-181

5.15.10.1.2 Alternative 2 (NER Plan and RP)...................................................................... 5-181

5.15.10.1.3 Alternative 3...................................................................................................... 5-182

5.15.10.1.4 Alternative 4...................................................................................................... 5-182

5.15.10.1.5 Alternative 5...................................................................................................... 5-182

5.15.10.1.7 Alternative 7 ...................................................................................................... 5-183

5.15.10.1.8 Alternative 8 ...................................................................................................... 5-184

5.15.10.2 Oyster Leases .................................................................................................... 5-185

5.15.10.2.1 No Action Alternative (Future without Project Conditions) ............................. 5-185

5.15.10.2.2 Alternative 2 (NER Plan and RP)...................................................................... 5-185

5.15.10.2.3 Alternative 3...................................................................................................... 5-187

5.15.10.2.4 Alternative 4...................................................................................................... 5-187

5.15.10.2.5 Alternative 5...................................................................................................... 5-187

5.15.10.2.6 Alternative 6...................................................................................................... 5-187

5.15.10.2.7 Alternative 7...................................................................................................... 5-188

5.15.10.2.8 Alternative 8...................................................................................................... 5-189

5.16 HAZARDOUS, TOXIC, AND RADIOACTIVE WASTES........................................ 5-195

[Phase I Environmental Site Assessment Findings].................................................................. 5-195

5.16.1 No Action Alternative (Future without Project Conditions).................... 5-195

5.16.2 Alternative 2 (NER Plan and RP) ............................................................ 5-195

5.16.2.1 Direct...................................................................................................................... 5-195

5.16.2.2 Indirect ................................................................................................................... 5-195

5.16.2.3 Cumulative............................................................................................................. 5-195

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5.16.3 Alternative 3............................................................................................. 5-195

5.16.4 Alternative 4............................................................................................. 5-195

5.16.5 Alternative 5............................................................................................. 5-195

5.16.6 Alternative 6............................................................................................. 5-195

5.16.7 Alternative 7............................................................................................. 5-196

5.16.8 Alternative 8............................................................................................. 5-196

5.17 UNAVOIDABLE ADVERSE EFFECTS ............................................................... 5-197

5.18 RELATIONSHIP OF SHORT-TERM USES AND LONG-TERM PRODUCTIVITY ..... 5-197

5.19 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES............ 5-197

5.20 MITIGATION.................................................................................................. 5-198

5.21 CUMULATIVE IMPACTS SUMMARY................................................................ 5-198

6.0 PUBLIC INVOLVEMENT............................................................... 6-1

6.1 NEPA SCOPING ................................................................................................ 6-1

6.2 OTHER PUBLIC COMMENTS............................................................................... 6-5

6.2.1 Federal and State Agencies.......................................................................... 6-5

6.2.2 Land Owner, Non-Governmental Organization (NGO), Parish and Other

Involvement ............................................................................................................. 6-5

6.2.3 Public Comments on the Draft EIS.............................................................. 6-6

7.0 COORDINATION AND COMPLIANCE........................................ 7-1

7.1 USACE PRINCIPLES AND GUIDELINES (P&G).................................................. 7-1

7.2 ENVIRONMENTAL COORDINATION AND COMPLIANCE ...................................... 7-1

7.2.1 U.S. Fish and Wildlife Coordination Act..................................................... 7-3

7.2.2 Clean Water Act – Section 404(b)(1) .......................................................... 7-6

7.2.3 Section 122 of the Rivers and Harbors Act ................................................. 7-7

7.2.4 Coastal Zone Management Act of 1972 ...................................................... 7-7

7.2.5 Endangered Species Act of 1973 ................................................................. 7-7

7.2.6 Magnuson-Stevens Fishery Conservation and Management Act of 1996; and

the Magnuson-Stevens Act Reauthorization of 2006 (Essential Fish Habitat)........ 7-8

7.2.7 Clean Air Act – Air Quality Determination................................................. 7-8

7.2.8 National Historic Preservation Act of 1966................................................. 7-8

7.2.9 Farmland Protection Policy Act (Prime and Unique Farmlands) ................ 7-8

7.2.10 Executive Order 13186 – Migratory Bird Habitat Protection...................... 7-9

7.2.11 Executive Order 12898 – Environmental Justice......................................... 7-9

7.2.12 Executive Order 13112 – Invasive Species ............................................... 7-10

7.2.13 Executive Order 11990 – Floodplain Management................................... 7-10

7.2.14 Executive Order 11988 – Protection of Wetlands ..................................... 7-10

7.2.15 Uniform Relocation Assistance and Real Property Acquisition Policies Act

of 1970 ................................................................................................................... 7-11

7.2.16 Louisiana State Rare, Threatened, and Endangered Species, and Natural

Communities Coordination.................................................................................... 7-11

7.2.17 Clean Water Act – Section 401 Water Quality.......................................... 7-11

8.0 CONCLUSIONS AND DETERMINATIONS................................. 8-1

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8.1 AREAS OF CONTROVERSY AND UNRESOLVED ISSUES ....................................... 8-1

8.2 CONCLUSIONS................................................................................................... 8-3

8.3 RECOMMENDATIONS......................................................................................... 8-3

9.0 DISTRIBUTION LIST AND OTHER.............................................. 9-1

9.1 DISTRIBUTION LIST........................................................................................... 9-1

9.2 LIST OF PREPARERS ........................................................................................ 9-19

9.3 LITERATURE CITED......................................................................................... 9-21

9.4 GLOSSARY ...................................................................................................... 9-32

9.5 ACRONYMS, ABBREVIATIONS, SYMBOLS, AND INITIALISMS ........................... 9-43

ATTACHMENT

ATTACHEMENT 1: NON-FEDERAL SPONSOR’S LETTER OF INTENT

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FIGURES

FIGURE 1.1. STUDY AREA................................................................................................................... 1-4

FIGURE 1.2. SUBUNITS WITHIN STUDY AREA. ............................................................................ 1-7

FIGURE 1.3: MORGANZA TO THE GULF...................................................................................... 1-15

FIGURE 1.4. OTHER RESTORATION PROJECTS IN THE VICINITY OF THE ARTM STUDY

......................................................................................................................................................... 1-29

FIGURE 2.1. ARTM CONCEPTUAL ECOLOGICAL MODEL ....................................................... 2-3

FIGURE 2.2. WEST - BAYOU PENCHANT SUB AREA. ................................................................ 2-12

FIGURE 2.3. LAND GAIN/LOSS RATES IN THE STUDY AREA. PERCENT PER YEAR BASED

ON 1985 TO 2008 RATES AND 1985 ACREAGE. (BASED ON BARRAS ET AL 2008 AND

BARRAS 2009). NEGATIVE NUMBERS INDICATE LAND LOSS...................................... 2-13

FIGURE 2.4. CENTRAL - LAKE BOUDREAUX SUB AREA......................................................... 2-16

FIGURE 2.5. EAST - GRAND BAYOU SUB AREA.......................................................................... 2-19

FIGURE 2.6. FLOWS AND CONSTRICTIONS IN THE WESTERN STUDY AREA.................. 2-21

FIGURE 2.7. FLOWS AND CONSTRICTIONS IN THE EASTERN STUDY AREA................... 2-22

FIGURE 3.1. CALCULATED STUDY AREA LAND LOSS RATE (1985-2008).............................. 3-5

FIGURE 3.2. LAND GAIN/LOSS RATES IN THE STUDY AREA – PERCENT PER YEAR

BASED ON 1985 TO 2008 RATES AND 1985 ACREAGE (BASED ON BARRAS ET AL. 2008

AND BARRAS 2009). NEGATIVE NUMBERS INDICATE LAND LOSS. .............................. 3-6

FIGURE 3.3 ALTERNATIVE 2. ALTERNATIVE 2 INCORPORATES 4 OF THE 8 TOTAL

MEASURES IN THE WEST BAYOU PENCHANT AREA, ALL 36 IN CENTER – LAKE

BOUDREAUX AND 17 OF THE 19 IN EAST – GRAND BAYOU SUBUNIT ....................... 3-25

FIGURE 3.4 ALTERNATIVE 3. ALTERNATIVE 3 INCORPORATES 6 MEASURES IN THE

WEST – BAYOU PENCHANT AREA, ALL 36 IN CENTER - LAKE BOUDREAUX AND 17

IN EAST - GRAND BAYOU. IT DIFFERS FROM ALTERNATIVE 2 BY THE

ADDITIONAL MEASURES IN THE WEST. ............................................................................ 3-26

FIGURE 3.5 ALTERNATIVE 4. ALTERNATIVE 4 INCORPORATES 4 MEASURES IN THE

WEST – BAYOU PENCHANT AREA, ALL 36 IN CENTER - LAKE BOUDREAUX AND 18

IN EAST - GRAND BAYOU. IT DIFFERS FROM ALTERNATIVE 2 BY HAVING TWO

ADDITIONAL AND ONE DIFFERENT MEASURE IN THE EAST...................................... 3-27

FIGURE 3.6 ALTERNATIVE 5. ALTERNATIVE 5 INCORPORATES 6 MEASURES IN THE

WEST – BAYOU PENCHANT AREA, 36 IN CENTER - LAKE BOUDREAUX AND 18 IN

EAST - GRAND BAYOU. THIS ALTERNATIVE IS A COMBINATION OF

ALTERNATIVES 3 AND 4........................................................................................................... 3-28

FIGURE 3.7 ALTERNATIVE 6. ALTERNATIVE 6 INCORPORATES 4 MEASURES IN THE

WEST – BAYOU PENCHANT AREA, 4 IN CENTER - LAKE BOUDREAUX AND 3 IN

EAST - GRAND BAYOU.............................................................................................................. 3-29

FIGURE 3.8 ALTERNATIVE 7. ALTERNATIVE 7 INCORPORATES ONLY 1 MEASURE

WHICH IS IN THE CENTER - LAKE BOUDREAUX SUBUNIT. THIS MEASURE

PROPOSES TO CHANGE THE OPERATION OF THE PROPOSED HOUMA

NAVIGATION CANAL LOCK COMPLEX. ............................................................................. 3-30

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FIGURE 3.9 ALTERNATIVE 8. ALTERNATIVE 8 INCORPORATES 22 MEASURES IN THE

CENTER - LAKE BOUDREAUX AREA AND 11 IN EAST - GRAND BAYOU. THIS

ALTERNATIVE IS A SUBSET OF ALTERNATIVE 2............................................................ 3-31

FIGURE 3.10 FEATURES LOCATED IN THE NORTH LAKE BOUDREAUX AREA FOR

ALTERNATIVES 2 THROUGH 5 AND 8.................................................................................. 3-32

FIGURE 3.11: CE/ICA OF FINAL ALTERNATIVES ...................................................................... 3-39

FIGURE 3.12: CE/ICA BEST BUY PLANS........................................................................................ 3-41

FIGURE 4.1. PROJECT AREA.............................................................................................................. 4-4

FIGURE 4.2. HISTORIC HURRICANE STORM TRACKS WITHIN 100 MILES OF THE

PROJECT AREA............................................................................................................................. 4-5

FIGURE 4.3. PROJECT AREA SOILS ............................................................................................... 4-10

FIGURE 4.4. PROJECT AREA POLYGONS USED IN LAND GAIN/LOSS ANALYSIS............ 4-21

FIGURE 4.5. HABITAT CLASSIFICATIONS IN THE PROJECT AREA FROM 1956 TO 2000

(BASED ON BARRAS ET AL. 2008)........................................................................................... 4-22

FIGURE 4.6. LAND GAIN/LOSS RATES IN THE PROJECT AREA – PERCENT PER YEAR

BASED ON 1985 TO 2008 RATES AND 1985 ACREAGE (BASED ON BARRAS ET AL. 2008

AND BARRAS 2009). NEGATIVE NUMBERS INDICATE LAND LOSS. ............................ 4-23

FIGURE 4.7. OYSTER SEED GROUNDS AND LEASES (AUGUST 2009 LOUISIANA

DEPARTMENT OF WILDLIFE AND FISHERIES DATA). ................................................... 4-42

FIGURE 4.8. ECOREGIONS IN THE PROJECT AREA. ................................................................ 4-55

FIGURE 4.9. LANDSCAPE SIMILARITY ZONES IN THE PROJECT AREA............................. 4-57

FIGURE 4.10. OIL AND GAS INFRASTRUCTURE IN THE PROJECT AREA.......................... 4-81

FIGURE 4.11. EXISTING FEDERAL AND LOCAL LEVEES IN THE VICINITY OF THE

PROJECT AREA AND PROPOSED MORGANZA TO THE GULF ALIGNMENT.

SOURCES: TERREBONNE PARISH CONSOLIDATED GOVERNMENT AND

INTERAGENCY PERFORMANCE EVALUATION TASK FORCE..................................... 4-84

FIGURE 5.1. FEATURE LOCATIONS................................................................................................. 5-6

FIGURE 5.2. AVERAGE ANNUAL HABITAT UNITS ASSOCIATED WITH

IMPLEMENTATION OF ALTERNATIVE 2 AS COMPARED TO NO ACTION. .............. 5-16

FIGURE 5.3. AVERAGE ANNUAL HABITAT UNITS ASSOCIATED WITH

IMPLEMENTATION OF ALTERNATIVE 3 AS COMPARED TO NO ACTION. .............. 5-17

FIGURE 5.4: AVERAGE ANNUAL HABITAT UNITS ASSOCIATED WITH

IMPLEMENTATION OF ALTERNATIVE 4 AS COMPARED TO NO ACTION............... 5-18

FIGURE 5.5. AVERAGE ANNUAL HABITAT UNITS ASSOCIATED WITH

IMPLEMENTATION OF ALTERNATIVE 5 AS COMPARED TO NO ACTION. .............. 5-19

FIGURE 5.6. AVERAGE ANNUAL HABITAT UNITS ASSOCIATED WITH

IMPLEMENTATION OF ALTERNATIVE 6 AS COMPARED TO NO ACTION. .............. 5-20

FIGURE 5.7. AVERAGE ANNUAL HABITAT UNITS ASSOCIATED WITH

IMPLEMENTATION OF ALTERNATIVE 7 AS COMPARED TO NO ACTION. .............. 5-21

FIGURE 5.8. AVERAGE ANNUAL HABITAT UNITS ASSOCIATED WITH

IMPLEMENTATION OF ALTERNATIVE 8 AS COMPARED TO NO ACTION. .............. 5-22

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FIGURE 5.9. PREDICTED AVERAGE ANNUAL SALINITY VALUES (PPT) FOR THE NO

ACTION ALTERNATIVE IN 2025. ............................................................................................ 5-37

FIGURE 5.10. PREDICTED CHANGES IN AVERAGE ANNUAL SALINITY VALUES (PPT) IN

2025 AS A RESULT OF IMPLEMENTATION OF ALTERNATIVE 2. NUMBERS

REPRESENT CHANGES IN COMPARISON TO THE NO ACTION ALTERNATIVE.

NEGATIVE VALUES REPRESENT A DECREASE IN SALINITY. ..................................... 5-38

FIGURE 5.11. PREDICTED CHANGES IN AVERAGE ANNUAL SALINITY VALUES (PPT) IN

2025 AS A RESULT OF IMPLEMENTATION OF ALTERNATIVE 3. NUMBERS

REPRESENT CHANGES IN COMPARISON TO THE NO ACTION ALTERNATIVE.

NEGATIVE VALUES REPRESENT A DECREASE IN SALINITY. ..................................... 5-39

FIGURE 5.12. PREDICTED CHANGES IN AVERAGE ANNUAL SALINITY VALUES (PPT) IN

2025 AS A RESULT OF IMPLEMENTATION OF ALTERNATIVE 4. NUMBERS

REPRESENT CHANGES IN COMPARISON TO THE NO ACTION ALTERNATIVE.

NEGATIVE VALUES REPRESENT A DECREASE IN SALINITY. ..................................... 5-40

FIGURE 5.13. PREDICTED CHANGES IN AVERAGE ANNUAL SALINITY VALUES (PPT) IN

2025 AS A RESULT OF IMPLEMENTATION OF ALTERNATIVE 5. NUMBERS

REPRESENT CHANGES IN COMPARISON TO THE NO ACTION ALTERNATIVE.

NEGATIVE VALUES REPRESENT A DECREASE IN SALINITY. ..................................... 5-41

FIGURE 5.14. PREDICTED CHANGES IN AVERAGE ANNUAL SALINITY VALUES (PPT) IN

2025 AS A RESULT OF IMPLEMENTATION OF ALTERNATIVE 6. NUMBERS

REPRESENT CHANGES IN COMPARISON TO THE NO ACTION ALTERNATIVE.

NEGATIVE VALUES REPRESENT A DECREASE IN SALINITY. ..................................... 5-42

FIGURE 5.15. PREDICTED CHANGES IN AVERAGE ANNUAL SALINITY VALUES (PPT) IN

2025 AS A RESULT OF IMPLEMENTATION OF ALTERNATIVE 7. NUMBERS

REPRESENT CHANGES IN COMPARISON TO THE NO ACTION ALTERNATIVE.

NEGATIVE VALUES REPRESENT A DECREASE IN SALINITY. ..................................... 5-43

FIGURE 5.16. PREDICTED CHANGES IN AVERAGE ANNUAL SALINITY VALUES (PPT) IN

2025 AS A RESULT OF IMPLEMENTATION OF ALTERNATIVE 8. NUMBERS

REPRESENT CHANGES IN COMPARISON TO THE NO ACTION ALTERNATIVE.

NEGATIVE VALUES REPRESENT A DECREASE IN SALINITY. ..................................... 5-44

FIGURE 5.17. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES FOR THE NO ACTION ALTERNATIVE IN 2025................... 5-45

FIGURE 5.18. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES FOR THE NO ACTION ALTERNATIVE IN 2025................... 5-46

FIGURE 5.19. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 2. ........................................................................................................................ 5-47

FIGURE 5.20. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 2. ........................................................................................................................ 5-48

FIGURE 5.21. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 3. ........................................................................................................................ 5-49

FIGURE 5.22. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 3. ........................................................................................................................ 5-50

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FIGURE 5.23. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 4. ........................................................................................................................ 5-51

FIGURE 5.24. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 4. ........................................................................................................................ 5-52

FIGURE 5.25. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 5. ........................................................................................................................ 5-53

FIGURE 5.26. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 5. ........................................................................................................................ 5-54

FIGURE 5.27. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 6. ........................................................................................................................ 5-55

FIGURE 5.28. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 6. ........................................................................................................................ 5-56

FIGURE 5.29. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 7. ........................................................................................................................ 5-57

FIGURE 5.30. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 7. ........................................................................................................................ 5-58

FIGURE 5.31. PREDICTED LOCATIONS OF ISOHALINE LINES DURING LOW

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 8. ........................................................................................................................ 5-59

FIGURE 5.32. PREDICTED LOCATIONS OF ISOHALINE LINES DURING HIGH

ATCHAFALAYA STAGES IN 2025 AS A RESULT OF IMPLEMENTATION OF

ALTERNATIVE 8. ........................................................................................................................ 5-60

FIGURE 5.33. LAND GAIN/LOSS RATES IN THE PROJECT AREA – PERCENT PER YEAR

BASED ON 1985 TO 2008 RATES AND 1985 ACREAGE (BASED ON BARRAS ET AL. 2008

AND BARRAS 2009). NEGATIVE NUMBERS INDICATE LAND LOSS. ............................ 5-68

FIGURE 5.34. LOCATIONS OF FEATURES WITH POTENTIAL NAVIGATION IMPACTS IN

THE WESTERN REGION OF THE STUDY AREA............................................................... 5-156

FIGURE 5.35. LOCATIONS OF FEATURES WITH POTENTIAL NAVIGATION IMPACTS IN

THE CENTRAL REGION OF THE STUDY AREA............................................................... 5-157

FIGURE 5.36. LOCATIONS OF FEATURES WITH POTENTIAL NAVIGATION IMPACTS IN

THE EASTERN REGION OF THE STUDY AREA................................................................ 5-158

FIGURE 5.37. LOCATIONS OF HYDRAULIC MODEL SALINITY POINTS WITH OVERLAY

OF CURRENT (AUGUST 2009) OYSTER LEASE AND SEED GROUND LOCATIONS. 5-190

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TABLES

TABLE 1.1. RELEVANCE OF PRIOR STUDIES, REPORTS, PROGRAMS, AND WATER

PROJECTS TO THE LCA-ARTM FEASIBILITY STUDY....................................................... 1-8

TABLE 1.2. USACE NEW ORLEANS DISTRICT REGULATORY BRANCH DEEPWATER

HORIZON EMERGENCY PERMIT REQUEST...................................................................... 1-32

TABLE 3.1. STUDY AREA LAND LOSS BASED ON USGS IMAGERY ANALYSIS. .................. 3-4

TABLE 3.2 SCREENING CRITERIA. ................................................................................................. 3-12

TABLE 3.3 STRATEGY MEASURES.................................................................................................. 3-16

TABLE 3.4 ELIMINATED MEASURES ............................................................................................. 3-18

TABLE 3.5 ALTERNATIVE MEASURES. ......................................................................................... 3-19

TABLE 3.6 LCA: ATCHAFALAYA CE/ICA:..................................................................................... 3-38

TABLE 3.7 LCA: ATCHAFALAYA CE/ICA: STEP 2....................................................................... 3-39

TABLE 3.8 LCA: ATCHAFALAYA CE/ICA: STEP 3....................................................................... 3-40

TABLE 3.9 NET INCREASE IN INCIDENTAL RECREATION BENEFITS ............................... 3-42

TABLE 3.10 - RELATIVE SEA LEVEL RISE ANALYSIS RESULTS FOR ALTERNATIVE 3 . 3-52

TABLE 3.11. ESTIMATES OF PROJECT BENEFITS WITHOUT HNC LOCK COMPLEX

IMPLEMENTATION. .................................................................................................................. 3-55

TABLE 3.12 MILESTONE SCHEDULE.............................................................................................. 3-57

TABLE 3.13: COST SHARING............................................................................................................. 3-62

TABLE 4.1. IMPAIRED WATER BODIES WITHIN THE PROJECT AREA. .............................. 4-14

TABLE 4.2. SALINITY RANGES FOR THE FOUR COASTAL WETLAND TYPES. ................. 4-17

TABLE 4.3. HABITAT TYPES (IN ACRES) IN THE PROJECT AREA FROM 1956 TO 2008

(BASED ON BARRAS ET AL. 2008 AND BARRAS 2009)....................................................... 4-20

TABLE 4.4. NONINDIGENOUS AQUATIC PLANT SPECIES IN THE ATCHAFALAYA AND

TERREBONNE BASINS (USGS 2009; LDWF 2005). ............................................................... 4-24

TABLE 4.5. FUNCTIONS OF INTEREST, STATUS, TRENDS, AND PROJECTIONS THROUGH

2050 OF AVIFAUNA, FURBEARERS, GAME MAMMALS, AND REPTILES IN THE

PROJECT AREA (LCWCRTF AND WCRA 1998)................................................................... 4-27

TABLE 4.6. NONINDIGENOUS AQUATIC ANIMAL SPECIES IN THE ATCHAFALAYA AND

TERREBONNE BASINS. ............................................................................................................. 4-30

TABLE 4.7. NUTRIA HARVESTED AND HERBIVORY DAMAGE ESTIMATES BY PARISH IN

SEASONS 1 THROUGH 7 OF THE COASTWIDE NUTRIA CONTROL PROGRAM

(WIEBE AND MOUTON 2009). .................................................................................................. 4-31

TABLE 4.8. TRENDS AND PROJECTIONS THROUGH 2050 OF FISH AND INVERTEBRATES

IN THE PROJECT AREA (LCWCRTF AND WCRA 1998).................................................... 4-38

TABLE 4.9. ESSENTIAL FISH HABITAT FOR VARIOUS LIFE STAGES OF BROWN SHRIMP,

WHITE SHRIMP, RED DRUM, AND GULF STONE CRAB (GMFMC 2004). .................... 4-44

TABLE 4.10. THREATENED AND ENDANGERED SPECIES IN THE STUDY AREA............. 4-45

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TABLE 4.11. RARE, THREATENED, AND ENDANGERED SPECIES AND NATURAL

COMMUNITIES OF TERREBONNE AND LAFOURCHE PARISHES – APRIL 2008

(LOUISIANA NATURAL HERITAGE PROGRAM). .............................................................. 4-49

TABLE 4.12. NR LISTED PROPERTIES WITHIN PROJECT BOUNDARY............................... 4-53

TABLE 4.13. FISHING LICENSES SOLD IN THE VICINITY OF PROJECT AREA- FISCAL

YEAR 2008. .................................................................................................................................... 4-62

TABLE 4.14. BOAT REGISTRATIONS IN THE VICINITY OF THE PROJECT AREA - FISCAL

YEAR 2008. .................................................................................................................................... 4-62

TABLE 4.15. HUNTING LICENSES SOLD IN THE VICINITY OF THE PROJECT AREA -

FISCAL YEAR 2008...................................................................................................................... 4-62

TABLE 4.16. PARISH AND CITY POPULATION AND HOUSING UNIT ESTIMATES FOR 1940

TO 2008........................................................................................................................................... 4-64

TABLE 4.17. PARISH POPULATION PROJECTIONS................................................................... 4-65

TABLE 4.18. 2007 EMPLOYMENT CHARACTERISTICS. NUMBER OF INDIVIDUALS

EMPLOYED BY INDUSTRY (PERCENT BY AREA IN PARENTHESES). ........................ 4-66

TABLE 4.19. PER CAPITA PERSONAL INCOME FROM 1970 TO 2007 (NOT ADJUSTED FOR

INFLATION).................................................................................................................................. 4-67

TABLE 4.20. DESIGNATED USES FOR STREAMS WITHIN THE PROJECT AREA (LAC

TITLE 33, CHAPTER 11)............................................................................................................. 4-73

TABLE 4.21. CARGO TRANSPORTED (IN THOUSANDS OF TONS) AND NUMBER OF

VESSELS ON WATERWAYS IN THE VICINITY OF THE PROJECT AREA IN 2007..... 4-75

TABLE 4.22. 2008 CROP AND LIVESTOCK PRODUCTION IN THE VICINITY OF THE

PROJECT AREA AND IN LOUISIANA (IN MILLIONS OF DOLLARS). ........................... 4-77

TABLE 4.23. STANDING TIMBER VALUES IN THE VICINITY OF THE PROJECT AREA AND

IN LOUISIANA. ............................................................................................................................ 4-77

TABLE 4.24. TOTAL LANDINGS OF FISH AND SHELLFISH (MILLIONS OF POUNDS,

MILLIONS OF DOLLARS). ........................................................................................................ 4-85

TABLE 5.1 ALTERNATIVE MEASURES. ........................................................................................... 5-4

TABLE 5.2. IMPACTS ASSOCIATED WITH CONSTRUCTION OF PROJECT FEATURES. .. 5-7

TABLE 5.3. WEIGHTED (DBA) SOUND LEVELS OF CONSTRUCTION EQUIPMENT AND

MODELED ATTENUATION AT VARIOUS DISTANCES1................................................... 5-66

TABLE 5.4. SUMMARY OF WETLAND VALUE ASSESSMENT VARIABLES ASSOCIATED

WITH EACH ALTERNATIVE AND TARGET YEAR*. ......................................................... 5-69

TABLE 5.5. AVERAGE ANNUAL HABITAT UNITS BY AREA AND HABITAT TYPE. .......... 5-73

TABLE 5.6. NET ACRES CREATED, RESTORED, AND/OR PROTECTED BY OTHER

FEDERAL, STATE, LOCAL, AND PRIVATE RESTORATION EFFORTS (USACE 2004). . 5-

79

TABLE 5.7. PROJECT MEASURES AND ASSOCIATED POTENTIAL FISHERY ACCESS

IMPACTS (REFER TO FIGURE 5.1 ABOVE OR APPENDIX L ANNEX 4 ENGINEERING

DRAWINGS FOR LOCATIONS OF MEASURES). ................................................................. 5-95

TABLE 5.8. STATE OYSTER LEASES POTENTIALLY IMPACTED BY PROJECT FEATURES.

....................................................................................................................................................... 5-186

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TABLE 5.9. MODELED AVERAGE MONTHLY SALINITY VALUES BY AREA IN 2025..... 5-191

TABLE 5.10. SUMMARY OF CUMULATIVE IMPACTS............................................................. 5-199

TABLE 6.1. CATEGORIZATION OF SCOPING COMMENTS BY DRAFT EIS SUBJECT

MATTER. P&N = PURPOSE AND NEED, ALT = ALTERNATIVES, AE = AFFECTED

ENVIRONMENT, EC = ENVIRONMENTAL CONSEQUENCES, AND CC =

CONSULTATION, COORDINATION, AND COMPLIANCE WITH REGULATIONS. ...... 6-4

TABLE 7.1. RELEVANT FEDERAL STATUTORY AUTHORITIES AND EXECUTIVE ORDERS

(NOTE: THIS LIST IS NOT COMPLETE OR EXHAUSTIVE) ............................................... 7-2

TABLE 7.2. RELEVANT STATE STATUTORY AUTHORITIES (NOTE: THIS LIST IS NOT

COMPLETE OR EXHAUSTIVE) ................................................................................................. 7-3

TABLE 9.1: DISTRIBUTION LIST....................................................................................................... 9-2

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VOLUME III APPENDICES

ENVIRONMENTAL REPORTS

APPENDIX A Biological Assessment

APPENDIX B U.S. Fish and Wildlife Service Coordination Letter and Report

APPENDIX C NOAA Fisheries Service Coordination Letter

APPENDIX D 404(b)(1) Water Quality Report

APPENDIX E Louisiana Coastal Resources Program Consistency Determination

APPENDIX F Cultural Resources with State Historic Preservation Officer

Coordination Letter

APPENDIX G Responses to Comments

FEASIBILITY REPORTS

APPENDIX H Value Engineering Report

APPENDIX I Adaptive Management / Monitoring Plan

APPENDIX J Real Estate Plan

APPENDIX K Economics

APPENDIX L Engineering

APPENDIX M Wetland Value Assessment (WVA) Model Report

APPENDIX N Phase I Environmental Site Assessment

APPENDIX O Micro-Computer Aided Cost Estimating System (MCACES)

Model Report / MCACES 2nd Generation (MII)

APPENDIX P Project Costs and Schedule Risk Analysis Report

APPENDIX Q Recreation Incidental Benefits

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and Multipurpose Operation of Houma Navigation Lock

Final EIS WRDA 2007 Section 7006(e)(3) 1-1 September 2010

1.0 STUDY INFORMATION

1.1 Study Authority

Title VII of the Water Resources Development Act (WRDA) 2007 authorizes the

Louisiana Coastal Area (LCA) ecosystem restoration program. Included within that

authority are requirements for comprehensive coastal restoration planning, program

governance, a Science and Technology Program, a program for the beneficial use of

dredged material, feasibility studies for restoration plans, project modification

investigations, and restoration project construction, in addition to other program

elements. This authorization was recommended by the Chief of Engineer’s Report, dated

January 31, 2005.

Under the 2007 WRDA Section 7006, the LCA program has authority for feasibilitylevel reports of six near-term critical restoration features. The excerpt below from

WRDA outlines the project authority for this report for the Convey Atchafalaya River

Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma

Navigation Lock projects:

SEC. 7003. LOUISIANA COASTAL AREA.

(a) IN GENERAL.-The Secretary may carry out a program for ecosystem restoration, Louisiana

Coastal Area, Louisiana, substantially in accordance with the report of the Chief of Engineers,

dated January 31, 2005.

SEC. 7006. CONSTRUCTI ON.

(3) PROJECTS SUBJECT TO REPORTS.—

(A) FEASIBILITY REPORTS.—Not later than December

31, 2008, the Secretary shall submit to Congress feasibility

reports on the following projects referred to in the restoration

plan:

(i) Multipurpose Operation of Houma Navigation

Lock at a total cost of $18,100,000.

(ii) Terrebonne Basin Barrier Shoreline Restoration

at a total cost of $124,600,000.

(iii) Small Diversion at Convent/Blind River at a

Total cost of $88,000,000

(iv) Amite River Diversion Canal Modification at a

total cost of $5,600,000.

(v) Medium Diversion at White’ s Ditch at a total

cost of $86,100,000.

(vi) Convey Atchafalaya River Water to Northern

Terrebonne Marshes at a total cost of $221,200,000.

(B) CONSTRUCTION.—The Secretary may carry out the

projects under subparagraph (A) substantially in accordance

with the plans and subject to the conditions, recommended

in a final report of the Chief of Engineers if a

favorable report of the Chief is completed by not later than

December 31, 2010.

(4) CONSTRUCTION.—No appropriations shall be made to

construct any project under this subsection if the report under

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and Multipurpose Operation of Houma Navigation Lock

Final EIS WRDA 2007 Section 7006(e)(3) 1-2 September 2010

paragraph (2) or paragraph (3), as the case may be, has not

been approved by resolutions adopted by the Committee on

This report is an integrated feasibility study and environmental impact statement (EIS)

conducted for the Convey Atchafalaya River Water to Northern Terrebonne Marshes and

Multipurpose Operation of Houma Navigation Lock projects. This report fulfills the

reporting requirement to Congress of Section 7006(e)(3) which directs the Secretary of

the Army to submit feasibility reports on the six projects included in that section by

December 31, 2008 and authorizes implementation of the projects provided a favorable

Chief of Engineers’ Report is completed no later than December 31, 2010.

1.2 Purpose and Scope

In November 2008, the U.S. Army Corps of Engineers (USACE) and the State of

Louisiana represented through the Coastal Protection and Restoration Authority (CPRA),

executed a single Feasibility Cost-Share Agreement (FCSA) covering six Louisiana

Coastal Area (LCA) near-term plan elements listed in Section 7006(e) of the Water

Resources Development Act, 2007. The six features will each go through a separate

feasibility analysis and environmental compliance review culminating in a single master

feasibility document. The cost-share during this feasibility phase is 50% Federal and

50% Non-Federal in total. However, the individual elements have been divided so that

each entity has lead responsibility for preparing three of the six report components. This

means that at the end of the feasibility phase the total cost will be shared on a 50/50 basis,

yet for work on each individual element during the feasibility phase the ratio of funds

expended by either the Federal or non-Federal sponsor will be higher depending upon

their level of responsibility. Although three of the studies will be lead by state teams,

each individual feasibility component will be conducted and written to meet USACE

planning and technical standards for a feasibility level document.

This document serves as an integrated feasibility study and environmental impact

statement conducted for the Convey Atchafalaya River Water to Northern Terrebonne

Marshes and Multipurpose Operation of Houma Navigation Lock projects (LCAARTM). This project was identified as a Near-term Critical Restoration Feature

Recommended for Study and Future Congressional Authorization in the LCA Main

Report dated January 21, 2005. In November 2007, WRDA passed, authorizing this and

other projects from the LCA Main Report.

The purpose of the proposed action is to reduce the current trend of marsh degradation in

the study area resulting from subsidence and sea level rise, erosion, saltwater intrusion,

and lack of sediment and nutrient deposition. The study proposes to accomplish this by

utilizing fresh water and nutrients from within the study area, the Atchafalaya River and

the Gulf Intracoastal Waterway (GIWW).

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Final EIS WRDA 2007 Section 7006(e)(3) 1-3 September 2010

1.3 Study Area

The LCA-ARTM Study Area (Figure 1.1) comprises approximately 1100 square miles

(~700,000 acres) in Southern Louisiana in the vicinity of the City of Houma and

Terrebonne Parish. The LCA-ARTM study area fits into the Louisiana Coastal Area

Ecosystem Restoration Study (LCA Study) Area, which has been identified as the

Louisiana coastal area from Mississippi to Texas. The proposed LCA-ARTM study area

is located in the Deltaic Plain within Subprovince 3, one of the four Subprovinces

identified in the LCA Study Area.

The overall study area is bound to the west by the Lower Atchafalaya River. The study

area is bound to the east by the Bayou Lafourche ridge. The study area is bound to the

north by the Bayou Black ridge, from the Lower Atchafalaya River to the City of Houma,

and by the Gulf Intracoastal Waterway from the City of Houma to the Bayou Lafourche

ridge. The southern boundary of the study was based on a delineation conducted in 2007

of coastal Louisiana vegetation types. The boundary roughly follows the transition

between saline and brackish marsh types identified by Sasser et al. (2008).

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010

Figure 1.1. Study area.

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Due to the magnitude of the study area, the entire LCA-ARTM study area was divided

into three subunits as shown in Figure 1.2. The three subunits are labeled as West -

Bayou Penchant Area, Central - Lake Boudreaux Area, and East - Grand Bayou Area.

Subunits have been separated by a combination of natural, physical, and geographic

features, and the limits of the subunits were developed by the project delivery team

(PDT). The separation of the study area allowed the PDT to evaluate specific needs

relative to each subunit.

The West – Bayou Penchant Area is the largest of the three subunits identified by the

LCA-ARTM PDT, measuring approximately 680 square miles in size. The area envelops

sections of the GIWW that connect Morgan City, Louisiana to Houma, Louisiana. The

name of the subunit lends itself to the presence of the Penchant Basin, which is one of the

larger, more signature features within the subunit. The boundaries of the subunit can be

characterized as the following: the northern limits of the West – Bayou Penchant Area

subunit follow the northern edge of Lake Palourde and extend eastward down the Bayou

Black Ridge. The eastern limits are mostly bound by Bayou du Large, and the western

limits trace the Lower Atchafalaya River south of Morgan City, then cut eastward and

line the edge of Four League Bay. Major freshwater delivery systems within the West –

Bayou Penchant Area subunit consist of the Atchafalaya River, Bayou Shaffer, Bayou

Boeuf, GIWW, Bayou Chene, Bayou Penchant, Bayou Copasaw, and Minors Canal.

Other significant features located within the study subunit include portions of the

proposed Morganza to the Gulf levee. The ecosystems within the West – Bayou

Penchant Area can be characterized as mostly forested swamps between the GIWW and

Bayou Black, floating freshwater marsh systems throughout the Penchant Basin, and

intermediate marsh systems starting in the vicinity of Lake de Cade. Brackish marsh

systems are also within the subunit, south of the intermediate zone.

The Central – Lake Boudreaux Area subunit, measuring approximately 210 square miles,

extends south of the GIWW at Houma, Louisiana and envelops the Houma Navigation

Canal. The limits of the subunit adjoin the West – Bayou Penchant Area subunit at

Bayou du Large. The eastern limit of the Central – Lake Boudreaux Area subunit

consists of Bayou Terrebonne. Major freshwater delivery features within the Central –

Lake Boudreaux Area include the GIWW, Houma Navigation Canal, Bayou du Large,

Bayou Grand Caillou, Bayou Petit Caillou, and Bayou Terrebonne. Other significant

features located within the study subunit include Lake Boudreaux, Lake Quitman, and the

proposed Houma Navigation Canal lock complex and Morganza to the Gulf levee. The

landcover within the Central – Lake Boudreaux Area can be characterized as mostly

urban and agriculture along Bayou Du Large, Bayou Grand Caillou, Bayou Petit Caillou,

and Bayou Terrebonne. Between the bayous, the stratification of ecosystems shifts from

forested swamps in the north, to freshwater marsh systems, to intermediate systems.

Brackish marshes are found around and south of Lake Boudreaux.

The East – Grand Bayou Area Subunit is located south of Larose, Louisiana and

measures approximately 185 square miles. The LCA-ARTM PDT identified the northern

limits of this study unit to be bound by the GIWW, the western limits to be bound by

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Bayou Terrebonne, and the eastern limits to be bound by the Bayou Lafourche ridge.

The name of the subunit lends itself to the presence of the Grand Bayou Basin, which is

one of the larger, more signature features within the subunit. Major freshwater delivery

features within the East – Grand Bayou Area include the GIWW, Bayou Pointe au Chien,

Grand Bayou, Bayou Blue, Grand Bayou Blue, and Cutoff Canal. Other significant

features that are present within the study area include St. Louis Canal, portions of the

Pointe au Chien Wildlife Management Area, and portions of the proposed Morganza to

the Gulf levee.

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Figure 1.2. Subunits within Study Area.

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1.4 History of Investigation

This study is designed to address ecosystem restoration problems and opportunities in the

study area. These have been documented since 1998 through numerous comprehensive

planning studies. Specifically, this study builds upon the following comprehensive

planning efforts for the Louisiana coastal area:

• Coast 2050

• Louisiana Coastal Area, Louisiana Ecosystem Restoration Study

• Integrated Ecosystem Restoration and Hurricane Protection: Louisiana’s

Comprehensive Master Plan for a Sustainable Coast

• Louisiana Coastal Protection and Restoration (LACPR) Technical Report

These comprehensive planning studies are discussed further in Section 1.5. Planning for

this study utilizes data from these reports, and alternative plans were formulated in

coordination with these plans.

1.5 Prior Reports and Existing Projects

A number of prior water resources development efforts are relevant to the LCA Program.

Table 1.1 lists these efforts and denotes how each is relevant to the LCA-ARTM study.

The specific efforts are detailed in Sections 1.5.1., 1.5.2, 1.5.3, 1.5.4.

Table 1.1. Relevance of prior studies, reports, programs, and water projects to the LCA-ARTM

Feasibility Study.

Prior Studies, Reports, Programs, and Water

Projects

Relevance to LCA-ARTM

Data Sour ce

Consistency

Structural

Measures

Non Str - uctural

Measures

Future Without

Project

Condition

Comprehensive Planning Studies (Section 1.5.1)

Coast 2050, 1999 X X X

Louisiana’s Comprehensive Master Plan for a Sustainable

Coast, 2007 X X X X X

Louisiana Coastal Protection and Restoration (LACPR),

2009 X X X X

Louisiana Coastal Area (LCA) Near Term Critical

Restoration Features X X X X X

Pr ior Studies, Reports and Water Projects (See Section 1.5.2 & 1.5.4)

An Environmental- Economic Blueprint for Restoring the

Louisianan Coastal Zone: The State Plan for the Wetlands

Conservation and Restoration Authority, 1994

X X

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Prior Studies, Reports, Programs, and Water

Projects

Relevance to LCA-ARTM

Data Sour ce

Consistency

Structural

Measures

Non Str - uctural

Measures

Future Without

Project

Condition

A White Paper- The State of Louisiana’s Policy for Coastal

Restoration Activities, 1995 X X

Section 905(b) (WRDA 1986) Analysis Louisiana Coastal

Area, Louisiana—Ecosystem Restoration X

Gulf Intracoastal Waterway (GIWW), 1826 and other dates X X

Atchafalaya Basin X X

Mississippi River and Tributaries (MR&T), 1928 X X

Mississippi River Gulf Outlet, September 1956 X

Morganza to the Gulf X X X X X

Donaldsonville, LA to the Gulf of Mexico X X X X X

Third Delta X X X X

Cooperative River Basin Studies X X X X X

Watershed Reports X X X

Inner Harbor Navigation Canal Lock Replacement Project,

1956 X

Lake Pontchartrain and Vicinity, Louisiana, Hurricane

Protection Project, 1965 X

Measures undertaken pursuant to the authorization provided

under the heading “Operation and Maintenance” in Title I,

Chapter 3 of Division B of Public Law 109-148, as

modified by Section 2304 Title II, Chapter 3 of Public Law

109-234, 2006

X X X

Bonnet Carré Spillway X

Mississippi and Louisiana Estuarine Areas, 1984 X X

Louisiana Coastal Area Louisiana,

Shore and Barrier Island Erosion, 1984 X X

Mississippi River Delta Study, 1990 X X

Louisiana Coastal Area, Louisiana, Water Supply, 1984 X X

Louisiana Coastal Area, Hurricane Protection, 1989 X X

Louisiana-Texas Intracoastal Waterway, New Orleans,

Louisiana to Corpus Christi, Texas, 1942 X X X

Mississippi River, Baton Rouge to the Gulf of Mexico,

Louisiana, 1945 X X

A Report on the Relationship of Agricultural Use of

Wetlands to the Conservation of Wetlands in Cameron

Parish, Louisiana, 1951

X

Relationship of Wildlife to Agricultural Drainage and

Economic Development of Coastal Marshes in Cameron

Parish, Louisiana, 1951

X

Survey and Report of Vermillion Corporation in Opposition

to Project (Fresh Water Bayou Canal Project), 1951 X

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Prior Studies, Reports, Programs, and Water

Projects

Relevance to LCA-ARTM

Data Sour ce

Consistency

Structural

Measures

Non Str - uctural

Measures

Future Without

Project

Condition

Barataria Bay, Louisiana, 1958 X X

New Orleans to Venice, Louisiana Hurricane

Protection, 1962 X

Larose to Golden Meadow Hurricane Protection Project,

1965 X

Hydrologic and Geologic Studies of Coastal Louisiana,

1973 X X

Environmental Atlas and Multi-Use Management Plan for

South-Central Louisiana, 1973 X

Study of Louisiana’s Major Estuaries and Adjacent

Offshore Waters LDWF, 1978 X

An Ecological Characterization Study of the Chenier Plain

Coastal Ecosystem of Louisiana and Texas, 1979 X

Mississippi Deltaic Plain Region Ecological

Characterization, 1980 X X

Grand Isle and Vicinity, Louisiana, Phase II General Design

Memorandum, 1980 X

New Orleans-Baton Rouge Metropolitan Area, Louisiana,

1981 X

Deep-Draft Access to the Ports of New Orleans and Baton

Rouge, Louisiana, 1981 X X X

Louisiana’s Eroding Coastline: Recommendations for

Protection, 1982 X X X

Proceedings of the Conference on Coastal Erosion and

Wetland Modification in Louisiana: Causes, Consequences,

and Options, 1982

X X X X

Louisiana Barrier Shoreline Feasibility Study, 1996 X X

Mississippi River Sediment, Nutrient and Freshwater

Redistribution Feasibility Study, 2000 X X X

Atchafalaya River and Bayous Chene, Boeuf, and Black,

Louisiana Feasibility Study X X X X X

Old River complex X X X X

Caernarvon Freshwater Diversion X X X X

Davis Pond Freshwater Diversion X X X X X

CWPPRA Projects Constructed or Under Construction X X X X X

CWPPRA Projects Authorized for Construction X X X X X

Greater New Orleans Hurricane and Storm Damage Risk

Reduction System (HSDRRS) X X X

Inner Harbor Navigation Canal (IHNC) Surge Barrier X

Laws and Programs (See Section 1.5.3)

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Prior Studies, Reports, Programs, and Water

Projects

Relevance to LCA-ARTM

Data Sour ce

Consistency

Structural

Measures

Non Str - uctural

Measures

Future Without

Project

Condition

The Coastal Wetlands Planning, Protection and

Restoration Act (CWPPRA) X X

USACE Continuing Authorities Program, 1996 X

Southeast Louisiana Urban Flood Control Project (SELA),

1996 X X

The Coastal Impact Assistance Program (CIAP) X X X X

Second Emergency Supplemental Appropriations Act to

Meet the Immediate Needs Arising from the Consequences

of Hurricane Katrina, 2005 (Public Law 109-062)

X X X

Department of Defense, Emergency Supplemental

Appropriations to Address Hurricanes in the Gulf of

Mexico, and Pandemic Influenza Act, 2006 (Public Law

109-148)

X X X X

Emergency Supplemental Appropriations Act for Defense,

the Global War on Terror, and Hurricane Recovery, 2006

(Public Law 109-234)

X X X X X

Louisiana Coastal Wetlands Conservation, Restoration and

Management Act, 1989 X X X X X

1.5.1 Federal

Several comprehensive planning efforts have significance to the LCA-ARTM Feasibility

Study, including the Coast 2050 Plan, Louisiana’s Comprehensive Master Plan for a

Sustainable Coast, and the LACPR technical report. These comprehensive planning

efforts are described below in chronological order.

Coast 2050 Plan, 1999

In 1998, Federal and state agencies, local governments, academia, numerous nongovernmental groups, and private citizens participated in developing the Coast 2050 Plan,

a conceptual plan for restoration of the Louisiana coast. The Plan was a direct outgrowth

of lessons learned from implementation of restoration projects through the Coastal

Wetlands Planning, Protection, and Restoration Act (CWPPRA) and other programs, and

reflected a growing recognition that a more comprehensive “systemic” approach to

restoring coastal wetlands was needed. The Plan formed the basis for the May 1999

905(b) reconnaissance report that preceded the LCA Ecosystem Restoration Study.

Louisiana Coastal Area (LCA), 2004

In 2000, the USACE and State of Louisiana initiated the Louisiana Coastal Area

Ecosystem Restoration Study to address Louisiana’s severe coastal land loss problem.

The goal of LCA is to achieve and sustain a coastal ecosystem that can support and

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protect the environment, economy, and culture of coastal Louisiana and thus, contribute

to the economy and well-being of the Nation. The LCA study focused on “lessons

learned” from previous Louisiana coastal restoration efforts, the Coast 2050 restoration

strategies, and the best available science and technology to develop a plan addressing the

most critical coastal ecological needs. The LCA Ecosystem Restoration Study and Final

Programmatic EIS were completed in 2004. Reports produced under the LCA-ARTM

study will be supplements to those documents. The 2004 LCA Ecosystem Restoration

Study and Final Programmatic EIS are hereby incorporated by reference into this

document.

Louisiana Coastal Protection and Restoration (LACPR), 2009

The Louisiana Coastal Protection and Restoration technical report includes analysis and

concepts for coastal restoration and “Category 5” hurricane risk reduction, exclusive of

normal policy. The USACE submitted a Preliminary Technical Report to Congress in

July 2006. A Draft Final Technical Report now under review includes different

alignments of structural measures, such as floodgates, floodwalls, and levees, to compare

relative reduction of risk of flooding and storm surge, including the possibility of

structural measures affecting the LCA-ARTM study. The Draft Final Technical Report

also includes nonstructural measures such as elevating homes. In addition, the

investigation reviews various wetland restoration measures and highlights the role of

wetlands in coastal risk reduction. A Final Draft Technical Report was sent to MVD and

HQ for review December 2008 and is currently undergoing IEPR.

Morganza to the Gulf

The Morganza to the Gulf Hurricane Risk Reduction Project is located in coastal

Louisiana approximately 60 miles southwest of New Orleans and includes portions of

Terrebonne and Lafourche Parishes (Figure 1.3). The project consists of 72 authorized

miles of levees and structures; approximately 80% of the authorized alignment overlays

existing hydrologic barriers. The Morganza to the Gulf project was authorized to provide

100-year level of hurricane and storm damage risk reduction based on feasibility reports

and Reports of the Chief of Engineers in 2002 and 2003, prior to development and

implementation of post-Katrina design criteria.

The authorized hurricane protection plan consisted of approximately 72-miles of earthen

levee, ten 56-ft. wide sector gate structures, three 125-ft. wide floodgates, 13 tidal

exchange structures, and a lock complex consisting of a lock in the Houma Navigation

Canal measuring 110 ft. wide by 800 ft. long, an adjoining floodgate measuring 250 ft.

wide and a dam closure. The structural features are integrated into the levee alignment to

provide flood protection, drainage, environmental benefit, and navigational passage.

A Post Authorization Change (PAC) Report is currently being developed to seek

reauthorization. The PAC report will evaluate benefits and costs for the authorized project

alternative (post-Katrina 35-year level of risk reduction) and for the post-Katrina 100-year

alternative. The alternative with the greatest net benefits will be selected as the recommended

plan and then feasibility-level designs and costs will be completed for that plan.

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A Revised Programmatic EIS (RPEIS) will be prepared for concurrent submittal with the

PAC Report. The RPEIS will document changes in existing conditions and evaluate all

direct and indirect environmental impacts of increased levee footprints resulting from the

post-Katrina design criteria. The RPEIS will include sufficient detail for any

constructible features (i.e. HNC Lock complex) so that no additional environmental

clearances will be required for those features upon signing of the Record of Decision

(ROD).

The Houma Navigation Canal (HNC) Lock Complex is a feature of the Morganza to the

Gulf of Mexico Hurricane Protection Project. It consists of a 110-ft. x 800-ft. lock, an

adjacent 250 ft.-wide sector gate, and a dam closure that tie into adjacent earthen levees

to reduce the risk of storm surge traveling up the HNC. Vessel traffic will pass through

the sector gate portion of the structure for the majority of conditions. However, when the

sector gates are closed, the lock will be utilized. The sector gates will be closed to

control chloride levels at the Houma water treatment plant and to reduce risk from storm

surge.

50% Design and Specifications on the HNC Lock Complex was complete in July 2008.

Design efforts on the lock will continue pending a favorable economic analysis at the

MVD Commander’s review conference, selection of a recommended plan (establish

design elevation), and receipt of additional funds. The Corps is not authorized to

construct the HNC Lock Complex as an independent, free-standing project or as a

separable element of the Morganza to the Gulf project. The Morganza to the Gulf

Hurricane Protection Project is NOT part of the Southeast Louisiana Hurricane and Storm

Damage Risk Reduction System (HSDRRS).

The local sponsor is moving ahead with plans to build an interim risk reduction system

along the authorized alignment in advance of Morganza to the Gulf. The general plan is

to construct first lift levees to elevation 10 ft. and install temporary barge gate structures,

all under the regular Corps permit process. The local sponsor desires to receive Work In

Kind (WIK) credit for the interim work. The local sponsor has completed construction of

the first lift for Reach J-1, as authorized in FY 04 Appropriations Act. The local sponsor

is 80% complete in constructing the first lift for levee Reach H-3, and is 10% complete in

constructing the first lift for Reach H-2. The remainder of the project is in PED.

The Morganza to the Gulf project is included in the LACPR study as Planning Unit 3-a,

and is part of this comprehensive system to provide higher levels of protection for the

Morganza area.

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As of July 2010, the following provides a status of portions of the Morganza to the Gulf

project:

Levee Reach J-1, First Lift, complete (WIK)

Features under construction

Levee Reach H-3, First Lift, 80% complete (WIK)

Levee Reach H-2, First Lift, 10% complete (WIK)

Pointe Aux Chenes Levee, First Lift, 100% P&S (WIK)

Features under Design

Levee Reach J-2, First Lift, 95% P&S (WIK)

Houma Navigation Canal (HNC) Lock and Floodgate, 50% P&S complete July 2008

Levee Reach F-1, 25% DDR

Levee Reach G-1, 35% DDR

Bayou Grand Caillou Floodgate, 35% DDR

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Figure 1.3: Morganza to the Gulf

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Prior Studies, Reports, and projects

In addition to the comprehensive planning efforts described above, the studies, reports,

and projects listed in Table 1.1 are relevant to the LCA-ARTM Feasibility Study as

noted.

Related Laws and Programs

Over the past three decades, both the Federal government and the State of Louisiana have

established policies and programs that are intended to halt and reverse the loss of coastal

wetlands and to restore and enhance ecosystem function.

1.5.1.1 Federal Laws and Programs

Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA), 1990

The Coastal Wetlands Planning, Protection, and Restoration Act of 1990 was the first

Federal statutory mandate for restoration of Louisiana’s coastal wetlands. The CWPPRA

Task Force is composed of five Federal agencies: U.S. Environmental Protection Agency

(USEPA), U.S. Fish and Wildlife Service (USFWS), U.S. Army Corps of Engineers

(USACE), National Marine Fisheries Service (NMFS), and Natural Resources

Conservation Service (NRCS), and the State of Louisiana. The authority required

preparation of a comprehensive restoration plan that would coordinate and integrate

coastal wetlands restoration projects to ensure the long-term conservation of coastal

wetlands of Louisiana. The plan was adopted in 1993.

The task force is also required to prepare an annual Project Priority List. CWPPRA

provides funds annually for coastal restoration planning and the construction of coastal

protection and restoration projects. As of July 2008, 145 active CWPPRA projects had

been approved, 74 had been constructed, 17 were under construction, and 26 had been

de-authorized or transferred to other programs.

USACE Continuing Authorities Program, 1992

Section 204 of the WRDA 1992, as amended in WRDA 2007 Section 2037, is a

"continuing authority" that authorizes the Secretary of the Army to plan, design, and

implement certain ecosystem restoration measures, subject to specified cost sharing,

cooperation, and positive Secretarial findings without additional project specific

Congressional authorization. Section 204 as amended authorizes the beneficial use of

sediments in connection with construction, operation, or maintenance dredging of an

authorized Federal water resources project.

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Coastal Impact Assistance Program (CIAP), 2001 and 2005

The Coastal Impact Assistance Program (CIAP) was originally authorized by Congress in

2001 in the Outer Continental Shelf Lands Act, as amended (31 U.S.C. 6301-6305).

Section 384 of the Energy Policy Act of 2005 (Public Law 109-58) authorized CIAP

funds to be distributed to Outer Continental Shelf oil and gas producing states to mitigate

the impacts of Outer Continental Shelf oil and gas activities for fiscal years 2007 through

2010. The state liaison for this program in Louisiana is the Louisiana Department of

Natural Resources (LDNR). The CIAP allocations have been used to fund various state

and local coastal activities and projects including: monitoring, assessment, research, and

planning; habitat, water quality, and wetland restoration; coastline erosion control; and

control of invasive non-native plant and animal species.

Second Emergency Supplemental Appropriations Act to Meet the Immediate Needs

Arising from the Consequences of Hurricane Katrina, 2005 (Public Law 109-062)

The Second Emergency Supplemental Appropriations Act to Meet the Immediate Needs

Arising from the Consequences of Hurricane Katrina, 2005 (Public Law 109-062) was

adopted by Congress on September 2, 2005. This law provided emergency supplemental

funding to repair damage to flood risk management and hurricane shore protection

projects.

Department of Defense, Emergency Supplemental Appropriations to Address

Hurricanes in the Gulf of Mexico, and Pandemic Influenza Act, 2006

(Public Law 109-148)

The “Department of Defense, Emergency Supplemental Appropriations to Address

Hurricanes in the Gulf of Mexico, and Pandemic Influenza Act, 2006” (Public Law 109-

148), provided funds for the LACPR efforts.

1.5.2 State

Coastal resource management in Louisiana formally evolved once Louisiana adopted and

began participating in the Federal Coastal Zone Management program in 1978. Shortly

thereafter, the State developed a coastal zone management plan. One of the primary

objectives of this plan was to ensure that future development activities within the coastal

area would be accomplished with the greatest benefit and the least amount of

environmental damage.

Louisiana Coastal Wetlands Conservation, Restoration and Management Act, 1989

In 1989, the constitution of the State of Louisiana was amended with enactment and voter

approval of Act 6 (LA. R.S. 49:213 et seq.), also known as the Louisiana Coastal

Wetlands Conservation, Restoration and Management Act. Act 6 designated the

Louisiana Department of Natural Resources as the lead State agency for the development,

implementation, operation, maintenance, and monitoring of coastal restoration projects.

LDNR had the lead for the development and implementation of state-sponsored coastal

restoration projects.

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Act 6 also created the Wetlands Conservation and Restoration Fund (WCRF), which

dedicates a portion of the state’s revenues from severance taxes on mineral production

(e.g., oil and gas) to finance coastal restoration activities and projects. Currently, the

WCRF provides approximately $25 million per year to support coastal restoration

activities and projects. Act 6 requires the State to prepare and annually update a “Coastal

Wetlands Conservation and Restoration Plan.” This plan provides location specific

authorizations for the funding of coastal restoration projects from the WCRF.

Act 8 of the First Extraordinary Session of 2005

In November 2005, Act 8 of the First Extraordinary Session of 2005 created the Coastal

Protection and Restoration Authority (CPRA) and charged it with coordinating the efforts

of local, state, and Federal agencies to achieve long-term and comprehensive coastal

protection and restoration. The CPRA created a Master Plan to integrate what had

previously been discrete areas of activity: flood risk management and wetland restoration.

Louisiana’s Comprehensive Master Plan for a Sustainable Coast, 2007

The Louisiana Legislature, through Act 8 of the First Extraordinary Session of the 2005

Louisiana Legislature, established the Coastal Protection and Restoration Authority

(CPRA) to develop, implement, make reports on, and provide oversight for a

comprehensive coastal protection master plan and annual coastal protection plans.

1.5.3 Local

Non-governmental organizations have also participated in various coastal restoration

projects. Public and private parties involved in wetlands preservation or restoration

activities in coastal Louisiana include Coastal America, Corporate Wetlands Restoration

Partnership, Gulf Coast Joint Venture, Audubon Society, National Fish and Wildlife

Foundation, The Nature Conservancy, and the National Wildlife Federation. These

efforts are primarily concerned with preservation. The restoration activities of these

organizations will support the overall goals of the LCA-ARTM study; however, these

efforts are small in scale and will not appreciably influence plan formulation.

1.5.4 Existing and Likely Future Water Projects

Several existing and authorized navigation, river flood risk management, hurricane storm

surge risk reduction, coastal restoration, and multi-purpose Operation and Maintenance

(O&M) projects are related to the Convey Atchafalaya River Water to Northern

Terrebonne Marshes Feasibility Study. These projects are briefly described below.

1.5.4.1 Navigation Projects

Gulf Intracoastal Waterway (GIWW)

The GIWW was authorized and construction was begun in the 1920’s. The GIWW traces

the U.S. coast along the Gulf of Mexico from Apalachicola Bay near Carrabelle, Florida

to the Mexican border at Brownsville, Texas. From its intersection with the Mississippi

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River, the waterway extends eastward for approximately 376 miles and westward for

approximately 690 miles. The GIWW runs contiguously through the LCA-ARTM study

area from Bayou Lafourche through Houma and on to Morgan City.

Houma Navigation Canal (HNC)

The Houma Navigation Canal (HNC) is a 36.6-mile navigation channel that begins at the

Gulf Intracoastal Waterway (GIWW) in Houma, Louisiana and extends southward to the

Gulf of Mexico. Terrebonne Parish constructed the canal in 1962 to provide direct access

to the nearby resources of the Gulf of Mexico. The channel was originally constructed

with a usable dimension of 15 ft. by 150 ft. from the GIWW to mile 0.0 of the HNC and

an 18-ft. contour to the Gulf of Mexico. The River and Harbor Act of October 23, 1962

provided for the maintenance of the HNC by the Federal government. Maintenance by

the United States was initiated on November 27, 1964

In accordance with Section 5 of the River and Harbor Act, approved March 4, 1915,

authority was granted on August 23, 1973 to increase the HNC project dimensions to

Elevation -18 feet Mean Low Gulf (MLG) by 300 feet in bottom width, between mile 0

and the Gulf of Mexico. This enlargement of the HNC was completed in July 1974.

Presently the Corps is undergoing a study to deepen this channel to either -18 feet or -20

feet NAVD88.

Atchafalaya River Deep Draft Channel

The project is located in south-central Louisiana in Assumption, St. Mary, and

Terrebonne Parishes, in the vicinity of Morgan City, Louisiana. It includes the

Atchafalaya River and adjacent areas south of Morgan City; Bayous Chene, Boeuf, and

Black and adjacent areas between the Atchafalaya River and Amelia, Louisiana; and

Atchafalaya Bay and the Gulf of Mexico, south of Morgan City. This project provides

for a 20-ft. deep by 400-ft. wide navigation channel.

1.5.4.2 Lower Atchafalaya Basin Floodway System

The entire Atchafalaya Basin is located in south-central Louisiana and extends from the

confluence of the Mississippi, Red and Atchafalaya Rivers near Simmesport, Louisiana

to the Gulf of Mexico south of Morgan City. The 833,000-acre Lower Atchafalaya Basin

Floodway is bounded on the north by U.S. 190, on the east and west by the Atchafalaya

Basin protection levees, and extends south to the Gulf of Mexico. The Lower

Atchafalaya Basin Floodway System project has two mutually supporting goals: to

preserve the habitat of the nation’s largest and oldest river-basin swamp and to ensure

that the Lower Atchafalaya Basin can pass a floodwater of 1.5 million cubic feet per

second as required by the Mississippi River and Tributaries Project (MR&T).

1.5.4.3 Hurricane Storm Surge Risk Reduction Projects

Morganza to the Gulf of Mexico Risk Reduction Project

In March 2002, a feasibility report and programmatic environmental impact statement

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(PEIS) entitled “Mississippi River & Tributaries – Morganza, Louisiana to the Gulf of

Mexico Hurricane Protection” was prepared by the USACE (USACE 2002). It is noted

that there is an addendum 1 to the report dated April 2003 and an addendum 2 dated

March 2004. It is further noted that the Chief’s Report (which the proposed authorizing

language references) is dated August 9, 2002. The Chief’s report was also supplemented

in 2003. The recommended plan proposed a series of flood protection measures and

included the following:

• construction of approximately 72 miles (116 kilometers) of levee south of Houma;

• construction of nine gated structures in various waterways and three floodgates in

the GIWW;

• construction of a lock structure and floodgate complex for the Houma Navigation

Canal (HNC); and

• construction and operation of new and replacement fish and wildlife structures in

selected locations to maintain tidal exchange.

The area to be protected by the levee system is a former major delta from a previous

course of the Mississippi River. As in other locations in south Louisiana, urban and

agricultural development has occurred along the banks of the remnant ridges of the delta.

Therefore, conveyance of freshwater via the Mississippi River through these remnant

channels is not practical. However, the close proximity of the area to the Atchafalaya

Basin offers other options of freshwater distribution. The GIWW is linked to the

Atchafalaya Basin and conveys water eastward to the area. The HNC intercepts these

flows before they reach the area of need and conveys them efficiently to the Gulf of

Mexico. If authorized, and with the levee system and water control structures in place,

the Atchafalaya River flows can be managed and distributed across the area. The

proposed Morganza to the Gulf levees and water control structures would convey

Atchafalaya River water eastward and would support the efforts proposed within the

LCA Plan, thus helping solve the saltwater intrusion problem in the Houma area. This

project presents a direct hydraulic relationship with the LCA-ARTM study.

1.5.4.4 Coastal Restoration Projects

Other LCA Projects. An LCA Project that could affect the LCA-ARTM is the

Beneficial Use of Dredged Material Program. A very promising option for restoring

coastal wetlands and reducing land loss is the beneficial use of dredged material.

USACE-MVN (Mississippi Valley Division - New Orleans District) has the largest

annual channel Operations and Maintenance (O&M) program in the nation and dredges

an average of 70 million cubic yards (mcy) of material annually during maintenance

dredging of navigation channels. Not all of this material is available for beneficial

placement in the coastal ecosystem; however, there is the potential to use up to 30 mcy

annually to enhance coastal wetlands through marsh creation, wetland nourishment,

barrier island restoration, ridge restoration, and other techniques. The ten year, $100

million LCA Beneficial Use of Dredged Material Program will provide the institutional

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framework to optimize the use of dredged material resulting from the maintenance of

federally maintained navigational channels to attain the LCA hydrogeomorphic and

ecosystem objectives. The beneficial use of dredged material could directly affect the

LCA-ARTM study area (Figure 1.4) by beneficially creating/enhancing marsh habitat

within the study area boundary.

Small Bayou Lafourche Reintroduction (LCA) project could supply fresh water to the

eastern portion of the LCA-ARTM study area. This restoration feature would reintroduce

flow from the Mississippi River into Bayou Lafourche. The flow would be continuous

and would increase riverine influence in the wetlands between Bayous Lafourche and

Terrebonne, south of the GIWW. Several alternatives are being considered which would

provide year-round flow into the bayou, including gated culverts and a pump/siphon

station at Donaldsonville, and initial E&D has been initiated under CWPPRA.

Additional features that would be required, regardless of the type of diversion structure

built, include modification of existing infrastructure, bank stabilization, dredging, and

channel improvements. The Bayou Lafourche project could have a synergistic

relationship with Convey Atchafalaya River Water to Northern Terrebonne Marshes.

The two projects could greatly reduce saltwater intrusion in the eastern Terrebonne

Marshes. Moreover, potential measures to improve distribution of Bayou Lafourche

reintroduction waters (e.g., enlargement of Bayou L’Eau Bleu and/or Grand Bayou)

could facilitate efforts to move Atchafalaya waters into areas of critical need. Given this

positive interrelationship, opportunities to maximize synergy between these two projects

should be fully evaluated in the feasibility study for the Bayou Lafourche reintroduction.

Maintain Land Bridge between Caillou Lake and Gulf of Mexico (LCA) could affect

salinity levels in the LCA-ARTM study area. This restoration feature would maintain the

land bridge between the Gulf of Mexico and Caillou Lake by placing shore protection in

Grand Bayou du Large to minimize saltwater intrusion. This feature would involve rock

armoring or marsh creation to plug/fill broken marsh areas on the west bank of lower

Grand Bayou du Large, thereby preventing a new channel from breaching the bayou bank

and allowing a new hydrologic connection with Caillou Lake. Some gulf shore armoring

would be needed to protect the area from erosion on the gulf shoreline. Gulf shoreline

armoring might be required where shoreline retreat and loss of shoreline oyster reefs has

allowed increased water exchange between the gulf and the interior water bodies

(between Bay Junop and Caillou Lake). Some gaps in the barrier between these two

water bodies would be closed to restore historic hydrologic connections. By reducing

marine influences in these interior areas, this feature would allow increased freshwater

influence from Four League Bay to benefit marshes in the surrounding areas.

Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) has several

projects in various stages that could have relationships to the LCA-ARTM study; these

projects are described below.

Atchafalaya Sediment Delivery (AT-02). The project is located east of the lower

Atchafalaya River navigation channel in the Atchafalaya River Delta, approximately 19

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miles southwest of Morgan City, Louisiana, in St. Mary Parish. Growth of the lower

Atchafalaya Delta has been reduced as a result of maintenance of the Atchafalaya River

navigation channel. Delta development in the shallow waters of Atchafalaya Bay is

dependent on distributary flows and the diversion of sediments into over-bank areas

through crevasse channels. Because of the placement of material dredged from the

navigation channel and sediment accumulation within the channels that decrease flow

efficiency, the open crevasse channels are frequently short-lived. As riverflow through a

crevasse channel is reduced, the amount of sediment that can be deposited in the delta is

likewise reduced, resulting in decreased marsh development. The purpose of this project

is to promote natural delta development by reopening two silted-in channels and using

those dredged sediments to create new wetlands. Approximately 720,000 cubic yards of

sediment were dredged from Natal Channel and Castille Pass in 1998. Over 12,000 feet

of channel were reopened, and more than 280 acres of new habitat were created by the

strategic placement of the dredged channels’ sediments. By reestablishing water and

sediment flow into the eastern part of the Atchafalaya Delta, an additional 1,200 acres of

new habitat are expected to be naturally created over the life of the project.

Construction was completed in 1998. A pre- versus post-construction habitat analysis

using aerial photography indicated that, while there was an increase in land of 78.4 acres,

the majority of the habitat created was represented by forested wetland (50.1 acres),

while fresh marsh and upland barren habitats accounted for 14 acres of gain each.

Although many of the dominant plant species are present in both created and reference

areas, the created areas contained different plant communities when compared to any

time period in the development of a natural crevasse splay that served as a reference area

for this project. Although the long-term effects on submerged aquatic vegetation (SAV)

are unclear, habitat mapping indicated an increase in SAV habitat of 221.5 acres from

1997 to 1998, but this is very close to the increases that were reported in the project area

pre-construction. Although habitat mapping has not been performed, satellite imagery

indicates that there have been significant increases in emergent acreage from 1998 to

2000. This project is not likely to have a major impact on the flows or water levels in the

LCA-ARTM study area.

Avoca Island Diversion and Land Building (TE-49). The project is located in the

Avoca Island area in St. Mary Parish, Louisiana. The Avoca Island area lost

approximately 5,000 acres of marsh between 1932 and 1990. Natural overbank flooding

into the area has been eliminated by channelization and construction of flood protection

levees, thereby preventing the input of fresh water, sediment, and nutrients. The goal of

this project is to rebuild eroded wetlands in the area through the diversion of fresh water,

sediment, and nutrients. A diversion structure will be installed through the Avoca levee

to allow water from Bayou Shaffer to enter Avoca Lake at a rate of 1,000 cubic feet per

second. A natural bayou will be used as the primary outfall channel for the diversion.

Outfall management measures will be evaluated and incorporated to increase benefits to

aquatic habitats in the island system. The Louisiana Coastal Wetlands Conservation and

Restoration Task Force approved funding for engineering and design at the January 2003

Task Force meeting. The project work plan for the engineering and design phase was

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submitted for program review in May 2003. Engineering data collection, including site

surveys and a geotechnical boring, is ongoing. This project would directly impact

freshwater marsh in the northwest portion of the LCA-ARTM study area and could

impact hydrology in the area as well.

Floating Marsh Creation Demonstration (LA-05). This project is located within the

fresh and intermediate marshes of the Mandalay Wildlife Refuge in Terrebonne Basin.

Tens of thousands of acres of marsh within the fresh and intermediate zones of the

Barataria and Terrebonne Basins converted to open water between 1968 and 1990. Large

areas of fresh and intermediate open water exist in marsh interiors, presenting

opportunities for reestablishment within those basins. These types of open water areas

are not well-suited for typical projects such as sediment diversions, beneficial use of

dredge material, or dedicated dredging because they are generally located at long

distances from natural sediment sources, frequently dredged navigation channels, or other

water bodies with bottom substrates containing material suitable for marsh creation.

Additionally, the substrate under these large areas of fresh and intermediate open water is

often fluid organic matter which would not support the weight of added sediment. The

purpose of this demonstration project is to develop and field test unique and previously

untested technologies for creating floating marsh for potential use in fresh and

intermediate zones.

The Louisiana Coastal Wetlands Conservation and Restoration Task Force approved

funding for this demonstration project at their January 2003 meeting. The goal of this

project is to develop methods for restoration of open areas within deteriorated floating

marsh and other freshwater areas where establishment of maidencane (Panicum

hemitomon) marsh is desired. In addition, the technology being developed is to be

transferable to wider applications across the LA coastal area. The first phase of the

project consisted of two components in which buoyant vegetated mats or artificial

floating systems (AFS) were developed and tested in a controlled environment during the

first two years of the project. Various combinations of plant species, planting methods,

structure materials and substrates were tested to determine optimal buoyancy and

structure design. In addition, plant response to environmental effects was evaluated in an

effort to identify methods to accelerate floating marsh mat development. For the second

phase of the project, the AFSs were then deployed into open water areas for field testing

on Mandalay National Wildlife Refuge in 2006. Monitoring of the AFSs field

performance is ongoing. This project is unlikely to affect the hydrology of the LCAARTM study area.

GIWW Bank Restoration of Critical Areas in Terrebonne (TE-43).

The project is located in the Terrebonne basin, in Terrebonne Parish, Louisiana. In the

past 20 years, as the efficiency of the Lower Atchafalaya River has decreased, Verrett

subbasin flooding and Atchafalaya River flows via the Gulf Intracoastal Waterway have

increased. Deterioration of fresh and intermediate wetlands, particularly of the floating

marshes in the upper Penchant basin, has been attributed to sustained elevated water

levels. In addition, floating marshes in some areas have become directly exposed to

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increased circulation through unnatural connections formed where channel banks

deteriorated. Conversely, losses in the central Terrebonne Parish marshes have been

attributed to the elimination of riverine inflow coupled with subsidence and altered

hydrology from canal dredging that facilitated saltwater intrusion. Increased flow of the

GIWW and wave pulses from navigation traffic is causing additional breakup and loss of

floating marshes in unprotected areas. This project is designed to restore critical lengths

of deteriorated channel banks and stabilize/armor selected critical lengths of deteriorated

channel banks with hard shoreline stabilization materials. This project has been largely

completed under the Coastal Impact Assistance Program (CIAP). This project could

impact the LCA-ARTM study area by reducing the loss rates of fresh marsh along the

GIWW.

Grand Bayou Hydrologic Restoration (TE-10). The project is located in Lafourche

Parish, Louisiana, approximately 5 miles southwest of Cut Off and south of Larose. The

project area includes part of the Pointe au Chien Wildlife Management Area. St. Louis

Canal and the Island Road Borrow Canal have re-routed water exchange westward via

Bayou Pointe au Chien to the Bayou Jean LaCroix watershed. Because this area has

higher salinities and twice the tidal amplitude as that of the Grand Bayou watershed into

which the area should drain, swamps and other salt-sensitive project-area wetlands have

suffered substantial deterioration and loss. Water exchange to the west through Bayou

Pointe au Chien would be halted by installing a major water control structure in Bayou

Pointe au Chien. Exchange with the Grand Bayou watershed would be restored by

installing new water control structures through the existing levee along the west side of

the Grand Bayou/Grand Bayou Canal. In April 2002, the project was downsized based

on the results of earlier engineering work. This project was deauthorized in January 2009

by the Restoration Task Force and will not be built under the CWPPRA program.

Brady Canal Hydrologic Restoration (TE-28). The project is located 21 miles

southwest of Houma, Louisiana, in Terrebonne Parish. The project is bounded by Turtle

Bayou to the east, Bayou DeCade to the south, and Bayou Penchant to the north. The

intermediate marshes in the area are highly fragmented and are the transitional areas

between the fresh and brackish zones. These marshes are extremely susceptible to erosion

and wetland loss. Land loss in the area has been caused by saltwater intrusion,

subsidence, and increased tidal energies. The project measures include replacing and

maintaining weirs, constructing a rock plug, stabilizing channel cross sections, and

restoring and maintaining channel banks. These measures will maintain and enhance

existing marshes in the project area by reducing the rate of tidal exchange. They will also

increase the utilization of sediment and fresh water introduced from the water control

structures and overbank flow along the north, east, and west sides of the project area.

Along the southern boundary, bank restoration and water control structures are used to

reduce tidal flow rate from channels into interior ponds, helping to improve the retention

of sediment and fresh water. Construction was completed in July 2000. A monitoring

plan has been developed, and the Louisiana Department of Natural Resources is currently

collecting data so that the project's effectiveness can be evaluated.

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North Lake Boudreaux Basin Freshwater Introduction and Hydrologic

Management (TE-32a). The project is located in Terrebonne Parish, approximately 5

miles southwest of Chauvin, Louisiana. The area is suffering from a lack of fresh water,

increasing the negative effects of saltwater intrusion into the north Lake Boudreaux basin

marshes. The purpose of the project is to reduce deterioration and loss of area marshes by

seasonally introducing fresh water from the Houma Navigation Canal. This project

includes the construction of a freshwater conveyance channel with water management

gates and the installation of several outfall management structures to allow drainage and

reduce ponding of water. The contracted Feasibility Study report has indicated that the

project, as proposed, can introduce the originally projected volumes of fresh water. Prior

to beginning engineering and design work, a landrights assessment is being conducted to

better determine where the project’s conveyance channel can be located. Proposed

features from this project were incorporated into the LCA-ARTM study.

Penchant Basin Natural Resources Plan, Increment 1 (TE-34). The project is bounded

on the north by the Gulf Intracoastal Waterway (GIWW), the east by a north/south line

from Lake DeCade to the GIWW, the south by Lake Mechant and Lost Lake, and to the

west by a north/south line from Lost Lake to Avoca Island in Terrebonne Parish,

Louisiana. Area problems include major hydrologic alterations, interior marsh erosion,

subsidence, saltwater intrusion, herbivory, and hurricane damage. This project will

combine the long-term realignment of Penchant Basin hydrology with restoration and

protection measures aimed at maintaining the physical integrity of the area during the

transition toward greater riverine influence. The project includes about 6,520 feet of

foreshore rock dike (shoreline protection) along the southern bank of Bayou Chene at its

intersection with Bayou Penchant and approximately 35 acres of marsh creation. Two

freshwater introduction structures, consisting of a) 10-48” flap gates in Superior Canal

and b) steel sheetpile weir with 10’ boat bay and six 5’ x 5’ flap gated openings at Brady

Canal, will be constructed to improve freshwater conveyance from Bayou Penchant into

the central Terrebonne marshes. On the north bank of Bayou Decade extending from

Lake Decade to Turtle Bayou (12,000 ft) an earthen embankment will be maintained and

from Voss Canal to Lost Lake (14,000 ft) an earthen embankment will be constructed to

4.0 feet NAVD88 with 6:1 side slopes and rock armoring on the south face. Within the

embankment, a sheetpile weir, with a 10 ft wide boat bay, will be constructed at each of

two existing channels that intersect Bayou Decade. The objectives of the project are to

eliminate erosion and create approximately 35 acres of emergent marsh along the

southern bank of Bayou Chene at its intersection with Bayou Penchant, convey

Atchafalaya River water, sediment, and nutrients to lower Penchant Basin tidal marshes

to offset subsidence and saltwater intrusion and maintain the integrity of a deteriorated

reach of the north bank of Bayou Decade to minimize encroachment of open water

marine influence. The Louisiana Coastal Wetlands Conservation and Restoration Task

Force approved this project on April 24, 1997. Planning, engineering and design of this

project included extensive data collection, hydrodynamic modeling, and related

investigations. This effort resulted in a change in scope to the project which was

approved by the Task Force in April 2008. Final engineering and design has been

completed and construction is scheduled to begin in the spring of 2010.

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South Lake DeCade Freshwater Introduction (TE-39). The project is located in

Terrebonne Parish, approximately 15 miles southwest of Houma, Louisiana. The project

area is experiencing marsh deterioration due to subsidence, rapid tidal exchange, and

human-induced hydrologic changes that result in increased salinities. Saltwater intrusion

has caused a shift in marsh type and a conversion of over 30 percent of emergent

vegetation to open water habitat. Shoreline erosion along the south embankment of Lake

De Cade threatens to breach the hydrologic barrier between the lake and interior marshes.

Proposed project components include installing three control structures along the south

rim of the lake and enlarging Lapeyrouse Canal to allow the controlled diversion of

Atchafalaya River water, nutrients, and sediments south into project area marshes. Outfall

management structures are planned in the marsh interior to provide better distribution of

river water. In addition, approximately 1.6 miles of foreshore rock dike is planned to

protect the critical areas of the south lake shoreline from breaching. After initial engineer

investigation the project was divided into two construction units. Construction unit one

will consist of the shoreline protection components. The other will be freshwater

introduction components. Engineering and design on the shoreline protection component

is complete and construction is pending Phase 2 approval. Data gathering and analysis is

being conducted on the freshwater diversion aspects of the project. This project could

synergistically increase beneficial impacts with the LCA-ARTM study if both are

implemented.

North Lake Mechant Landbridge Restoration (TE-44). The project is located in the

Terrebonne Basin, in Terrebonne Parish, Louisiana. The project would protect and restore

a critical landbridge barrier between the easily erodible fresh marshes north of Bayou De

Cade and the higher saline environment of Lake Mechant. At the present shoreline

erosion rate, the north Lake Mechant shore will soon fail to act as a barrier, allowing the

hydrologic connection between Lake Mechant and the fresher marshes to the north. In

addition, erosion and deterioration along the banks of Raccourci Bayou are threatening to

enlarge and straighten this winding tidal pass into a major conduit for water exchange.

These changes will accelerate the loss of the remaining interior marshes, extend lake-like

conditions, and increase salinities north to Bayou De Cade. Should shoreline breaching

and enlargement of tidal channels allow high tidal energy conditions to intrude into the

project area, the organic interior marshes would likely experience increased loss rates.

Dredged material from northern Lake Mechant will be used to create marsh. Smooth

cordgrass (Spartina alterniflora) will also be planted along the shorelines of Lake

Mechant, Goose Bay, and Lake Pagie. The project will also repair breeches formed by

erosion and oilfield access canals which threaten the integrity of the landbridge. The

Louisiana Department of Natural Resources has completed project engineering and

design. The Louisiana Coastal Wetlands Conservation and Restoration Task Force

granted construction approval of construction unit one on August 7, 2002, which included

shoreline vegetation plantings and were installed in summer 2003. Approval of

construction unit two was granted on October 2004, which includes dedicated dredging

for marsh creation and several other bank stabilization measures. Problems surrounding

the recently established public oyster seed grounds and several private oyster leases in

Lake Mechant were resolved and construction of that unit was completed in late 2009.

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West Lake Boudreaux Shoreline Protection and Marsh Creation (TE-46). The

project is located in the Terrebonne Basin along the western shoreline of Lake Boudreaux

in Terrebonne Parish, Louisiana. The west bank of Lake Boudreaux has experienced high

erosion rates due to wind-driven waves and high water. The entire historical lake rim is

gone, exposing the organic soil of the interior marsh to high-energy wave action. Most of

the remaining shoreline is less than 100 feet in width and has been breached in several

places. If this erosion is not stopped, the interior marsh and adjacent infrastructure will be

compromised. Continued shoreline loss will convert the productive shallow, open water

areas behind the shoreline to a less productive, open lake habitat. The project's objectives

include: reducing erosion of the west Lake Boudreaux shoreline to protect 80 acres of

emergent marsh and submerged aquatic vegetation (SAV); maintaining the shallow, open

water habitat, including its SAV, located west of the lake rim; and creating 284 acres of

marsh along the southwestern shoreline of Lake Boudreaux and at interior marsh sites

through the deposition of dredged material. Containment dikes will be used to hold the

dredged material in the marsh creation areas. The borrow site, from where the dredged

material will be extracted, will be located in Lake Boudreaux east of the project site. In

an effort to lessen or halt shoreline erosion, 13,000 linear feet of rock dike will be

constructed in three sections along the western shoreline of Lake Boudreaux, from Hog

Point south to Hog Point Canal. This will include “fish dips” for the exchange of

material, nutrients, and organisms between the interior marsh and the lake's main body.

Elsewhere, an earthen plug will be constructed to prevent unwanted water exchange. The

project also calls for construction of 4,000 linear feet of earthen dike. In addition, existing

openings will be enlarged and/or new openings created in the pumping station spoil bank

to facilitate the exchange of water and organisms between the project area's north and

south ponds. This project was selected for Phase I (engineering and design) funding at the

January 2002 CWPPRA Task Force meeting and was approved for Phase II

(construction) at the February 2006 task force meeting. This project could synergistically

increase beneficial impacts with the LCA-ARTM study if both are implemented.

Central Terrebonne Freshwater Enhancement (TE-66). The project area is located in

Terrebonne Basin in Terrebonne Parish. The Bayou Dularge Ridge historically restricted

the Gulf marine influence into Central Terrebonne marshes forming a diagonal restriction

extending from northeast to southwest, where the Atchafalaya influence is prominent.

The Grand Pass is currently a 900 ft wide artificial cut through the Bayou Dularge Ridge

south of Lake Mechant. The pass is mainly used by commercial and recreational

fisherman as a shortcut to the gulf and has greatly eroded to a point of approximately 36

feet deep that well exceeds optimal utility. The expansion of the pass to its current size

has allowed for a substantial alteration of historic salinity and hydrology and

consequently a broad area of the Central Terrebonne marshes are currently suffering

some of the highest loss rates in the state. The project will reestablish historic hydrologic

and salinity conditions by reducing the artificial intrusion of Gulf marine waters via the

Grand Pass into the Central Terrebonne marshes while enhancing the influence of the

Atchafalaya River waters into the area. A structure consisting of rock barge bay would be

constructed to reduce the size of the opening by up to 90% to 150' wide and 15' deep. The

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project would reestablish the historic ridge function of Bayou Dularge that separated

Lake Mechant from the gulf and moderate salinities that have greatly impacted the

marshes to the north of Lake Mechant. The project will also increase the Atchafalaya

influence in the area by modifying the current structure located in Liners Canal north of

Lake Decade to increase freshwater introduction to Lake Decade by an estimated 500 cfs

and provide maintenance dredging at Minors Canal to maintain optimal freshwater

conveyance from the GIWW into Lake Decade. The project is currently in the Planning

and Design Phase. The project team is developing surveying, geotechnical investigations,

and modeling requirements necessary to proceed to 30% design review. The project is

scheduled to request Phase II funding at the January 2012 Task Force meeting. This

project could synergistically increase beneficial impacts with the LCA-ARTM study if

both are implemented.

In early 2001, the Barataria-Terrebonne National Estuary Program (BTNEP) and the

Greater Lafourche Port Commission fostered a partnership with other organizations to

reestablish a chenier ridge and associated coastal marsh habitats in southeast Louisiana.

This partnership was born from a desire to further the knowledge and expand the focus of

habitat restoration in coastal Louisiana from purely a vision that supported marsh

restoration to one that encompassed other natural landscape features. Louisiana’s

unparalleled coastal wetland loss problem means dire consequences for many species of

birds. But of equal importance are the distributary ridges and chenier ridges that too are

being lost at an alarming rate. These ridge habitats and associated wetlands are

extremely important for millions of migrating Neotropical songbirds that cross the Gulf

of Mexico in the spring each year on their way back to their breeding grounds in the

eastern United States and Canada. Currently, the Greater Lafourche Port Commission is

in the process of reestablishing a maritime forest ridge in the vicinity of Bayous Cochon

and Moreau just north of the port at Fourchon, LA. BTNEP is serving as a co-lead

implementer of this project along with the Greater Lafourche Port Commission and is

helping to coordinate discussions and on-the-ground planning and construction. In

addition, BTNEP is providing funding for this project. This program could benefit the

LCA-ARTM study area by impacting hydrology and salinities in the area, depending on

the locations chosen for restoration of ridge habitat.

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Figure 1.4. Other Restoration Projects in the Vicinity of the ARTM Study.

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1.5.5 Deepwater Horizon Oil Spill

The impacts of the Deepwater Horizon oil spill on coastal Louisiana are uncertain at this

time (August 2010). The impacts of the oil spill as well as the various emergency actions

taken to address oil spill impacts (e.g., use of oil dispersants, creation of sand berms, use

of Hesco baskets, rip-rap, sheet piling and other actions) could potentially impact

USACE water resources projects and studies within the Louisiana coastal area, including

the LCA-ARTM project. Potential impacts could include factors such as changes to

existing, future-without, and future-with-project conditions, as well as increased project

costs and implementation delays. The USACE will continue to monitor and closely

coordinate with other Federal and state resource agencies and local sponsors in

determining how to best address any potential problems associated with the oil spill that

may adversely impact project implementation. Supplemental planning and

environmental documentation may be required as information becomes available. If at

any time petroleum or crude oil is discovered on project lands, all efforts will be taken to

seek clean up by the responsible parties, pursuant to the Oil Pollution Act of 1990 (33

U.S.C. 2701 et seq.).

Ongoing documentation of the impacts associated with the Deepwater Horizon Oil spill

can be found in several governmental sources. The USFWS Situation Report for August

2, 2010 (http://www.fws.gov/home/dhoilspill/pdfs/MondayAugust22010.pdf) indicates

the following environmental-related Deepwater Horizon oil spill information: 563

personnel are actively engaged in the response, working to protect wildlife and their

habitats, including 36 national wildlife refuges. They are also assessing the damage from

the oil spill in preparation for the work that will be needed to restore the Gulf of Mexico.

Some 1,643 visibly oiled birds have been collected alive by the U.S. Fish and Wildlife

Service, the states and our partners in response to the Deepwater Horizon oil spill. Of

those, 594 birds have been rehabilitated and released. Another 1,451 visibly oiled birds

have been collected dead. Aerial operations over Louisiana observed an oil sheen

covering 300 acres in the northeastern portion of Barataria Bay. A heavily oiled coastline

covering about one-half mile was found at Bayou Chalond and heavy oil and tar balls

were observed on landfall east of Point-Au-Fer and along Timbalier Island. Beached bird

surveys were conducted in Texas, Louisiana, Mississippi, Alabama and Florida. Aerial

missions are scheduled for Southwest Pass, Chandeleur Islands, Biloxi Marsh, Barataria

Bay, Terrebonne, Marsh Islands, Atchafalaya Delta, Point-Au-Fer and Timbalier Bay.

• Overall number of personnel responding: approximately 30,100

• Total vessels responding: more than 4,500

• Total boom deployed: more than 2,155 miles

• Boom available: more than 856 miles

• Oily water recovered: more than 34.7 million gallons

• Estimated 11.14 million gallons of oil burned

• Estimated total of more than 1.84 million gallons of dispersant used including:

o Estimated more than 1.07 million gallons surface dispersant used

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o Estimated more than 771,000 gallons of sub-sea dispersant used

• Estimated approximately 632 miles of Gulf Coast shoreline is currently oiled—

approximately 365 miles in Louisiana, 111 miles in Mississippi, 68 miles in

Alabama, and 88 miles in Florida.

The USACE, New Orleans District Regulatory Branch has considered and responded to

approximately 55 emergency permits related to the Deepwater Horizon oil spill (Table

1.2). Emergency permits have the following clause that provides for removing, relocating

or altering permitted structures if necessary and upon due notice from the Corps. The

clause would pertain to future actions by the United States, such as proposed Louisiana

Coastal Area restoration projects:

The permittee understands and agrees that, if future operations by the United

States require the removal, relocation, or other alteration, of the structure or

work herein authorized, or if, in the opinion of the Secretary of the Army or his

authorized representative, said structure or work shall cause unreasonable

obstruction to the free navigation of the navigable waters, the permittee shall be

required upon due notice from the Corps of Engineers, to remove, relocate, or

alter the structural work or obstructions caused thereby, without expense to the

United States. No claim shall be made against the United States on account of any

such removal or alteration.

As is evident from the numerous ongoing actions, the dynamic nature of the impacts

associated with the Deepwater Horizon oil spill will likely require additional

consideration in the near future for USACE Civil Works projects.

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Table 1.2. USACE New Orleans District Regulatory Branch Deepwater Horizon Emergency Permit Request(source: http://www.mvn.usace.army.mil/pao/mvnoilspill.asp dated August 4, 2010)

DA Number Project Name Applicant Action Date Rec'd Date Issued Date Denied Date Withdrawn

MVN-2010-01038-EJJ Deepwater Horizon Oil Spill - LANG - Pier on MRGO to Unload Oil Spill Booms - St Bernard Parish St. Bernard Parish NOD- 20 5-May-10 6-May-10

MVN-2010-01039-EFF

Deepwater Horizon Oil Spill - LADWF - InstallConcrete Fill to Close Gaps on Elmers Island -Jefferson Parish

La.

Wildlife&Fisher

ies

NOD20 6-May-10 7-May-10

MVN-2010-01039-EFF*

Deepwater Horizon Oil Spill - LADWF - InstallConcrete Fill to Close Gaps on Elmers Island -Jefferson Parish

La.

Wildlife&Fisher

ies

NOD20 1-Jul-10 2-Jul-10

MVN-2010-01041-WB

Deepwater Horizon Oil Spill - Lafourche ParishGovernment - Sand bags along Fourchon Beachbetween Parish Line & LA Hwy 3090

Lafourche Ph

Government

NOD20 10-May-10 11-May-10

MVN-2010-01041-WB*

Deepwater Horizon Oil Spill - Lafourche ParishGovernment - Riprap and bulkhead along FourchonBeach between Parish Line & LA Hwy 3090

Lafourche Ph

Government

NOD20 17-May-10 17-May-10

MVN-2010-01041-WB*

Deepwater Horizon Oil Spill - Lafourche ParishGovernment - HESCO baskets along Fourchon Beachbetween Parish Line & LA Hwy 3090

Lafourche Ph

Government

NOD20 21-May-10 21-May-10

MVN-2010-01041-WB*

Deepwater Horizon Oil Spill - Lafourche ParishGovernment - Elevate a protective Berm at ThunderBayou-Lafourche Ph

Lafourche Ph

Government

NOD20 2-Jul-10 2-Jul-10

MVN-2010-01066-ETT

Deepwater Horizon Oil Spill - State of Louisiana -Barrier Island Sand Berm Project - Jefferson,Plaquemines, St Bernard Parishes

La. OCPR NOD- 20 12-May-10 27-May-10

MVN-2010-01066-ETT*

Deepwater Horizon Oil Spill - State of Louisiana -Modification to Barrier Island Sand Berm Project -Jefferson, Plaquemines, St Bernard Parishes

La. OCPR NOD- 20 6-Jul-10 15-Jul-10

MVN-2010-01098-EFF Deepwater Horizon Oil Spill - Plaquemines Parish - Sandbag Operation at Pelican and Scofield Islands La. DNR NOD- 20 14-May-10 14-May-10

MVN-2010-01098-EFF* Deepwater Horizon Oil Spill - Plaquemines Parish - Additional Sandbags at Pelican and Scofield Islands Plaquemines Ph Govt NOD- 20 8-Jul-10 8-Jul-10

MVN-2010-01136-WJ

Deepwater Horizon Oil Spill- State of LouisianaCreate Sand Protection Berm- Isles Denieres Chain,Terrebonne Ph.

La. OCPR NOD- 20 18-May-10 6-Jul-10

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Table 1.2. USACE New Orleans District Regulatory Branch Deepwater Horizon Emergency Permit Request(source: http://www.mvn.usace.army.mil/pao/mvnoilspill.asp dated August 4, 2010)

DA Number Project Name Applicant Action Date Rec'd Date Issued Date Denied Date Withdrawn

MVN-2010-1143-EFF

Deepwater Horizon Oil Spill- State of LouisianaInstall pilings and booms east of Biloxi Marsh Area,St. Bernard Ph

La. OCPR NOD- 20 19-May-10 20-May-10

MVN-2010-01149-EJJ Deepwater Horizon Oil Spill - Tiger Dams on Grand Isle Jefferson Ph Government NOD- 20 21-May-10 21-May-10

MVN-2010-01151-WB Deepwater Horizon Oil Spill - Terrebonne Parish Government, Trinity Island, sand bags Terrebonne Ph Govt NOD- 20 24-May-10 4-Jun-10

MVN-2010-01152-EOO Deepwater Horizon Oil Spill - Little Lake Club - Marsh Plugs N of Turtle Bay - Jefferson Little Lake Club NOD- 20 24-May-10 26-May-10

MVN-2010-01265-EJJ Deepwater Horizon Oil Spill; sand bags at Shell Cut and Chaland Pass Plaquemines Ph Govt NOD- 20 7-Jun-10 15-Jun-10

MVN-2010-01267-WB

Deepwater Horizon Oil Spill - Terrebonne ParishGovernment, install sheetpile with tiebacks for Closureof Canal 19 on timbalier Island

Terrebonne Ph

Govt

NOD20 4-Jun-10 4-Jun-10

MVN-2010-01271-EOO Deepwater Horizon Oil Spill - Rock Jetties at 5 Passes, Grand Isle Area - Jefferson, Plaquemines Jefferson Ph Government NOD- 20 8-Jun-10 3-Jul-10

MVN-2010-01291-EBB Deepwater Horizon Oil Spill - Queen Bess Island Inflatable Coffer Dams - Jefferson Jefferson Ph Government NOD- 20 8-Jun-10 9-Jun-10

MVN-2010-01335-WB

Deepwater Horizon Oil Spill - Cameron Parish Gov -Emergency authorization, HESCO Baskets/Sand Bagson Rockefeller WMA - Cameron

Cameron Ph

Govt

NOD20 11-Jun-10 11-Jun-10

MVN-2010-01337-EKK

Deepwater Horizon Oil Spill - Amigo Enterprises -Emergency authorization, Breton Sound Dock Upgrade- Plaquemines

Amigo

Enterprises

NOD20 11-Jun-10 11-Jun-10

MVN-2010-01337-EKK*

Deepwater Horizon Oil Spill - Amigo Enterprises -Emergency authorization, Breton Sound Dock Upgrade(new pumps and culvert) - Plaquemines

Amigo

Enterprises

NOD20 8-Jul-10 8-Jul-10

MVN-2010-01338-WJJ Deepwater Horizon Oil Spill, Terrebonne Parish, Dredge and Place Fill to Create Embankment Terrebonne Ph Govt NOD- 20 11-Jun-10 15-Jun-10MVN-2010-01339-EFF

Deepwater Horizon Oil Spill - Plaquemines Parish -Emergency authorization. Dredging of Happy JackCanal & Wilkinson Canal - Plaquemines

Plaquemines Ph

Govt

NOD20 11-Jun-10 24-Jun-10

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Table 1.2. USACE New Orleans District Regulatory Branch Deepwater Horizon Emergency Permit Request(source: http://www.mvn.usace.army.mil/pao/mvnoilspill.asp dated August 4, 2010)

DA Number Project Name Applicant Action Date Rec'd Date Issued Date Denied Date Withdrawn

MVN-2010-01342-EOO

Deepwater Horizon Oil Spill - Jefferson Parish -Emergency Authorization, Piling and boomInstallations in Caminada Pass, Barataria Pass, PassAbel, Four Bayou Pass and Cheniere Ronquille Pass -Jefferson & Plaquemines

Jefferson PhGovernment

NOD20 11-Jun-10 14-Jun-10

MVN-2010-01342-EOO* Deepwater Horizon Oil Spill - Modification to booms in Pass Abel and Four Bayou Pass Jefferson Parish Jefferson Ph Government NOD- 20 18-Jun-10 18-Jun-10

MVN-201001350-EJJ

Deepwater Horizon Oil Spill - LA DOTD - EmergencyAuthorization for Temporary by-pass road & bridge onLA Hwy 624, north of Bayou La Loutre - St. Bernard

LaDOTD NOD- 20 14-Jun-10 14-Jun-10

MVN-2010-01372-EKK Deepwater Horizon Oil Spill - Breton Sound Dock Expansion on Bayou La Loutre - St Bernard Amigo Enterprises NOD- 20 16-Jun-10 16-Jun-10

MVN-2010-01442-WB

Deepwater Horizon Oil Spill - Vermilion Parish -Emergency Authorization to construct 14 blkhds acrossbreaches along coast of Vermilion Parish

Vermilion Parish

Police Jury

NOD20 21-Jun-10 25-Jun-10

MVN-2010-01473-WB

Deepwater Horizon Oil Spill - BP - EmergencyAuthorization for Piling/Boom Installation atRaccourci Lake - Lafourche

BP America

Production Co

NOD20 22-Jun-10 24-Jun-10

MVN-2010-01478-EKK Deepwater Horizon Oil Spill - Pass Abel, Boom Installation - Jefferson & Plaquemines BP America Production Co NOD- 20 23-Jun-10 24-Jun-10

MVN-2010-01518-EPP

Deepwater Horizon Oil Spill - Amigo Enterprises -Breton Sound Dock Expansion on Bayou La Loutre &MRGO - St. Bernard Parish

Amigo

Enterprises

NOD20 25-Jun-10 25-Jun-10

MVN-2010-01521-EKK Deepwater Horizon Oil Spill - Pass Abel, West Boom Installation - Jefferson & Plaquemines BP America Production Co NOD- 20 25-Jun-10 28-Jun-10

MVN-2010-01549-WJJ

Deepwater Horizon Oil Spill - EmergencyAuthorization to Fill Breaks along Twin PipelineCanal Levee - Terrebonne, Lafourche

Terrebonne Ph

Levee and

Conservation

District

NOD20 29-Jun-10 7-Jul-10

MVN-2010-01550-EPP Deepwater Horizon Oil Spill - Plaquemines Parish - X- Tex Fabric Fence near Wilkinson Canal Plaquemines Ph Govt NOD- 20 29-Jun-10 30-Jun-10

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Table 1.2. USACE New Orleans District Regulatory Branch Deepwater Horizon Emergency Permit Request(source: http://www.mvn.usace.army.mil/pao/mvnoilspill.asp dated August 4, 2010)

DA Number Project Name Applicant Action Date Rec'd Date Issued Date Denied Date Withdrawn

MVN-2010-01554-WB

Deepwater Horizon Oil Spill - EmergencyAuthorization for Pilings and Booms at Wine Island &Racoon Island in Terrebonne Ph

La.

Wildlife&Fisher

ies

NOD20 30-Jun-10 1-Jul-10

MVN-2010-01579-WB

Deepwater Horizon Oil Spill - EmergencyAuthorization for installation of Tiger Dams on ElmersIsland; Breach 4 to Bayou Thunder Breach, GOM -Lafourche & Jefferson Parishes

Lafourche Ph

Government

NOD20 30-Jun-10 1-Jul-10

MVN-2010-01581-EKK Deepwater Horizon Oil Spill - Caminada Pass, Boom Installation - Jefferson Ph BP America Production Co NOD- 20 30-Jun-10 1-Jul-10

MVN-2010-01588-WJJ

Deepwater Horizon Oil Spill - Terrebonne Levee &Conservation District - Emergency Authorization ToInstall Geotextile Fabric along Twin Pipeline CanalLevee - Terrebonne, Lafourche

Terrebonne Ph

Levee and

Conservation

District

NOD20 2-Jul-10 7-Jul-10

MVN-2010-01593-EFF Deepwater Horizon Oil Spill, Clear, grade, and deposit fill to improve property for oil spill response staging Amigo Enterprises NOD- 20 2-Jul-10 2-Jul-10

MVN-201--01635-EPP

Deepwater Horizon Oil Spill - Mi SWACO - GrandIsle Beach Sand Cleaning Project EmergencyAuthorization - Jefferson

Mi SWACO NOD- 20 8-Jul-10 9-Jul-10

MVN-2010-01700-WB

Deepwater Horizon Oil Spill - Pilings along CasseTete and Calumet Islands for boom installation -Lafourche Ph

BP America

Production Co

NOD20 13-Jul-10 14-Jul-10

MVN-2010-01705-WB

Deepwater Horizon Oil Spill - Install HESCO basketsalong Fourchon Beach from Breach No. 4 to BayouThunder - Lafourche Ph

BP America

Production Co

NOD20 13-Jul-10 15-Jul-10

MVN-2010-01722-EBB

Deepwater Horizon Oil Spill - Piles and booms inBarataria Pass to protect Mendicant Island, Queen BessIsland and B. Beauregard Island - Jefferson Ph

BP America

Production Co

NOD20 15-Jul-10 16-Jul-10

MVN-2010-01722-EBB*

Deepwater Horizon Oil Spill - Modification of Pilesand booms in Barataria Pass to protect MendicantIsland, Queen Bess Island and B. Beauregard Island -Jefferson Ph. The modification includes relocating andadding more pilings.

BP America

Production Co

NOD20 22-Jul-10 22-Jul-10

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Table 1.2. USACE New Orleans District Regulatory Branch Deepwater Horizon Emergency Permit Request(source: http://www.mvn.usace.army.mil/pao/mvnoilspill.asp dated August 4, 2010)

DA Number Project Name Applicant Action Date Rec'd Date Issued Date Denied Date Withdrawn

MVN-2010-01723-EPP Deepwater Horizon Oil Spill - Piles and booms in Cat Bay along Cat Bay Islands - Jefferson Ph BP America Production Co NOD- 20 15-Jul-10 16-Jul-10

MVN-2010-01723-EPP*

Deepwater Horizon Oil Spill - Modification to pilesand booms in Cat Bay along Cat Bay Islands -Jefferson Ph

BP America

Production Co

NOD20 23-Jul-10 23-Jul-10

MVN-2010-1728-EPP

Deepwater Horizon Oil Spill - BP America ProductionCo - Piles in Cat Bay along (3) Bird Islands -Plaquemines

BP America

Production Co

NOD20 16-Jul-10 16-Jul-10

MVN-2010-1728-EPP*

Deepwater Horizon Oil Spill - BP America ProductionCo - Modification to Piles in Cat Bay along (3) BirdIslands - Plaquemines

BP America

Production Co

NOD20 23-Jul-10 23-Jul-10

MVN 2010-01753 EKK

Deepwater Horizon Oil Spill - BP America ProductionCo - Surf washing of sand on Grand Terre - JeffersonPh

BP America

Production Co

NOD20 19-Jul-10 27-Jul-10

MVN-2010-01780-EFF Deepwater Horizon Oil Spill - Piling and Boom Installation in Caminada Bay - Lafourche & Jefferson BP America Production Co NOD- 20 20-Jul-10 21-Jul-10

MVN-2010-01783-ETT Deepwater Horizon Oil Spill - Marsh Barriers in Blind & Customhouse Bays - Plaquemines PH La. OCPR NOD- 20 21-Jul-10 pending

MVN-2010-01784-EOO

Deepwater Horizon Oil Spill - Hesco Baskets, PointCheniere Ronquille to Grand Bayou Pass -Plaquemines

Plaquemines Ph

Govt

NOD20 21-Jul-10 30-Jul-10

MVN-2010-01879-EFF

Deepwater Horizon Oil Spill - Dredge Wilkinson Canalto access staging area at Myrtle Grove Marina -Plaquemines

Plaquemines Ph

Govt

NOD20 4-Aug-10 pending

* Indicates modification to

previously issued permit

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1.6 Planning Process and Report Organization

The Convey Atchafalaya River Water to Northern Terrebonne Marshes study follows the

USACE’s six-step planning process specified in Engineering Regulation (ER) 1105-2-

100. The planning process identifies and responds to problems and opportunities

associated with the Federal objective and specified state and local concerns. This

integrated report includes elements of both the planning process and sections specific to

the NEPA review of the study.

1.6.1 The Six Step Planning Process

The USACE planning process involves six steps:

1. Identifying problems and opportunities

2. Inventorying and forecasting conditions

3. Formulating alternative plans

4. Evaluating alternative plans

5. Comparing alternative plans

6. Selecting a plan

1. Identify Problems and Opportunities: The specific problems and opportunities are

identified, and the causes of the problems discussed and documented. Planning goals

are set, objectives established, and constraints identified. An initial statement of

problems and opportunities was previously developed and presented in the LCA

Study, and reflects the priorities and preferences of the Federal Government, the nonFederal sponsors, and other groups that participated in the LCA Study process. This

problem identification step has been updated and refined to reflect the enhanced

understanding of the process and problems affecting the study area since the

completion of the LCA Study in 2004 (see section 2.4 below).

Resource constraints must be considered in plan formulation. Resource constraints

are those associated with limits on knowledge, expertise, experience, ability, data,

information, money, and time to reaffirm the recommended project or to formulate

and analyze additional alternatives in the decision document. Legal and policy

constraints are defined by law, including Congressional authorizations and

appropriations, USACE regulations, policy and guidance. Specific legal and policy

constraints that may affect plan development include the requirements to operate and

maintain authorized projects in the study area and NEPA requirements for preparing

the EIS.

2. Inventory and Forecast Resource Conditions: This step characterizes and assesses

conditions in the LCA-ARTM study area as they currently exist and forecasts the

most probable without-project condition (no action alternative) over the period of

analysis. This assessment gives the basis by which to compare various alternative

plans and their impacts. The without-project condition is what the river basin and its

uses are anticipated to be like over the 50-year planning period without any

restoration implemented as part of the study. The with-project condition is what the

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study area and its uses are anticipated to be like if restoration measures, identified in

each alternative, are implemented.

3. Formulate Alternative Plans: Alternative plans will be developed in a systematic

manner to ensure that reasonable alternatives were evaluated. The alternative plans

considered in the 2004 LCA Study will be reevaluated to determine if they still

provide a reasonable array of plans that would achieve study planning objectives

within constraints, and solve the problems and realize the opportunities that were

identified in Step 1 of the planning process. The alternatives previously identified at

the beginning of the LCA planning process, and, as appropriate, additional

alternatives, will be further screened and refined in subsequent iterations throughout

the planning process utilized in this decision document. In this manner, the decision

document will be used to affirm, reformulate, or modify the project goals identified in

the LCA Study.

4. Evaluate Alternative Plans: The evaluation of each alternative consists of measuring

or estimating the ecosystem benefits (acres of habitat or stream miles restored, tons of

sediment delivered to the system, etc.), costs, technical limitations, and risk and

uncertainty of each plan, and determining the difference between the without- and

with-project conditions. Project evaluation criteria will be directly linked to the

overall goals and objectives of restoring coastal Louisiana and to the specific

planning objectives and purposes of the critical project recommended by the Chief of

Engineers on 31 January 2005.

The criteria will be used to measure project outputs (benefits) and will be based on

metrics that can measure the range of potential effects that a plan may have on

increasing ecosystem value and productivity. The criteria will include ecosystem

restoration metrics that will provide quantifiable measures of how well an alternative

plan meets defined hydrologic, water quality, water sediment transport, salinity, or

other ecological goals. The criteria will be linked to the overall goals and objectives

of the LCA study and to the specific planning objectives and purposes of the LCAARTM project as described in the study. The metrics that will form the basis of the

criteria must be measurable, predictable by accepted models, supported by scientific

and technical data, and be specific enough to differentiate between alternative plans

and reasonable increments within those plans.

5. Compare Alternative Plans: During the alternative plan comparison, plans (including

the no action plan) are compared against each other, with emphasis on the outputs and

effects that will have the most influence in the decision making process. A

comparison of the outputs of the various plans may be made utilizing the Cost

Effectiveness/Incremental Cost Analysis. Once the beneficial and adverse effects of

each alternative plan, including project costs, have been estimated, the alternative

plans will be ranked in order of increasing costs. A cost-effectiveness analysis will

be performed, wherein the project evaluation criteria will be used to select the least

costly plans that deliver about the same level of outputs as other plans.

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6. Select Recommended Plan: The culmination of the planning process is the selection

of the recommended plan, or, alternately, the decision to take no action. Decisionmaking for the selection of a recommended plan begins at the District level and

continues at the Headquarters level through subsequent reviews and approval. For

this study, the final decision-maker is the Secretary of the Army, who has delegated

final approval of the study to the Assistant Secretary of the Army for Civil Works.

1.6.2 Report Organization

The chapter headings and order in this report generally follow the outline of the required

NEPA documentation for an EIS. Chapters of the report relate to the six steps of the

planning process in ER 1105-2-100 as follows:

• Chapter 2: Need For and Objectives of Action

This chapter addresses the first step in the planning process. In the first step of the

planning process, the study area problems and opportunities are defined in addition to the

constraints, goals, and objectives. An initial statement of problems and opportunities was

developed for the 2004 LCA report which reflected the priorities and preferences of the

Federal government, non-Federal sponsor, and other stakeholders. This report presents

an updated problem identification that includes enhanced understanding of the process

and problems of the study area.

• Chapter 3: Alternatives

The third chapter of this report addresses the third, fifth, and sixth steps in the planning

process. Step three of the planning process is the formulation of alternative plans.

During this step, the plans developed in the 2004 LCA report were reevaluated. The fifth

step in the planning process addresses comparisons of the alternative plans with emphasis

on the outputs and effects of each alternative. During the sixth step of the planning

process, the selection of the recommended plan is made based upon the comparison of

the alternative plans.

• Chapter 4: Affected Environment

The fourth chapter of this report addresses the second step of the planning process which

requires an inventory and forecast of resources within the study area. The inventory and

forecast of the study area provides the without project condition and is the basis of

comparison for the alternatives.

• Chapter 5: Environmental Consequences

The fifth chapter of this report covers the fourth step of the planning process which

evaluates the effects of the proposed alternative plans in terms of ecosystem benefits.

The evaluation criteria are based on the overall goals and objectives of the LCA program

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and specific planning objectives and purposes of the near-term critical restoration

projects recommended in the 2005 Chief of Engineers Report.

1.7 USACE Campaign Plan

The USACE has developed a Campaign Plan with a mission to “provide vital public

engineering services in peace and war to strengthen our Nation’s security, energize the

economy, and reduce risk from disasters.” This Campaign plan is shaping USACE

command priorities, focusing transformation initiatives, measuring and guiding progress,

and helping the USACE adapt to the needs of the future.

USACE Campaign Plan Goals and Objectives Summary

• Goal 1: Deliver USACE support to combat, stability and disaster operations

through forward deployed and reach back capabilities.

o Objective 1a: USACE is ready, responsive and reliable in delivering high

performance, all hazard, and contingency mission execution in a worldwide theater of operations.

o Objective 1b: Prepare Theater Engineer Commands (TEC) to support

Combatant Commanders throughout the spectrum of operations.

o Objective 1c: Establish human resources and family support programs that

promote readiness and quality of life.

o Objective 1d: Institutionalize USACE capabilities in interagency policy

and doctrine.

• Goal 2: Deliver enduring and essential water resource solutions through

collaboration with partners and stakeholders.

o Objective 2a: Deliver integrated, sustainable, water resources solutions.

o Objective 2b: Implement collaborative approaches to effectively solve

water resource problems.

o Objective 2c: Implement Streamlined and Transparent Regulatory

Processes to Sustain Aquatic Resources.

o Objective 2d: Enable Gulf Coast recovery.

• Goal 3: Deliver innovative, resilient, sustainable solutions to the Armed Forces

and the Nation.

o Objective 3a: Deliver sustainable infrastructure via consistent and

effective military construction and real estate support to customers.

o Objective 3b: Improve resilience and lifecycle investment in critical

infrastructure.

o Objective 3c: Deliver reliable infrastructure using a risk-informed asset

management strategy.

o Objective 3d: Develop and apply innovative approaches to delivering

quality infrastructure.

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• Goal 4: Build and cultivate a competent, disciplined, and resilient team equipped

to deliver high quality solutions.

o Objective 4a: Identify, develop, maintain, and strengthen technical

competencies in selected Communities of Practice (CoP).

o Objective 4b: Communicate strategically and transparently.

o Objective 4c: Standardize business processes.

o Objective 4d: Establish tools and systems to get the right people in the

right jobs then develop and retain this highly skilled workforce.

This study addresses two points of the USACE Campaign Plan. The second goal of the

USACE Campaign Plan is addressed by this study since it is an element of the LCA

ecosystem restoration plan on the Gulf Coast. This study also addresses the third goal

through the application of the planning process to formulate, analyze, and evaluate

alternative designs in pursuit of a sustainable, environmentally beneficial, and costeffective ecosystem restoration design.

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2.0 NEED FOR AND OBJECTIVES OF ACTION

2.1 National Objectives

The national or Federal objective of water and related land resources planning is to

contribute to national economic development consistent with protecting the nation’s

environment, pursuant to national environmental statutes, applicable executive orders,

and other Federal planning requirements. Contributions to national economic

development (NED) are increases in the net value of the national output of goods and

services, expressed in monetary units. Contributions to NED are the direct net benefits

that accrue in the planning area and the rest of the nation.

The Corps has added a second national objective for Ecosystem Restoration in response

to legislation and administration policy. This objective is to contribute to the nation’s

ecosystems through ecosystem restoration, with contributions measured by changes in the

amounts and values of habitat.

Ecosystem restoration is one of the primary goals of the USACE Civil Works Program.

The USACE objective in ecosystem restoration planning is to contribute to national

ecosystem restoration (NER). NER contributions include increases in the net quantity

and/or quality of desired ecosystem resources. NER measurements are changes in

ecological resource quality as a function of improvement in habitat quality and/or

quantity. The units are expressed quantitatively in physical units or indexes that are not

based on monetary units. Net changes are measured in the study area and in the rest of

the Nation. Single-purpose ecosystem restoration plans shall be formulated and

evaluated in terms of their net contributions to increases in NER output.

NER contributions were considered in the alternatives analysis for this study. Under

Title VII of WRDA 2007, any project or separable project element under LCA may be

justified by the environmental benefits alone and economic justification is not required if

the Secretary determines that the project or activity is cost-effective. This exemption

does not apply for any project that is not predominately related to the protection,

preservation, and restoration of the coastal Louisiana ecosystem.

Louisiana contains one of the largest expanses of coastal wetlands in the contiguous

United States and accounts for 90 percent of the total coastal marsh loss occurring in the

Nation. The ARTM study area is an essential ecosystem since it includes wetland

habitats, essential fish habitat, and has high fish and wildlife values. These ecosystems

provide habitat for migratory birds, wildlife, finfish, shellfish, and other aquatic

organisms including threatened or endangered species.

2.2 Public Concerns

The National Environmental Policy Act (NEPA) of 1969 established a nationwide policy

to include a detailed statement of the environmental impact of the proposed action in

every recommendation or report on proposals for major Federal actions significantly

affecting the environment. Such detailed statements are referred to as environmental

impact statements (EIS).

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A notice of intent (NOI) to prepare a draft EIS for the Louisiana Coastal Area (LCA)

Convey Atchafalaya River Water to Northern Terrebonne Marshes Restoration

Feasibility Study was published in the Federal Register (volume 73, number 246) on

December 22, 2008.

The intent of the NOI is to announce the United States Corps of Engineers’ (Corps)

intention to prepare a draft EIS that addresses the Convey Atchafalaya River Water to

Northern Terrebonne Marshes restoration project, which was identified in the LCA

Ecosystem Restoration Plan as a near-term critical restoration project.

The NEPA also provides for an early and open public process for determining the scope

of issues, resources, impacts, and alternatives to be addressed in an EIS. This process is

referred to as scoping. The scoping report documents scoping comments from interested

parties and describes where in the EIS individual comments should be addressed. It also

outlines the study background and scoping process to date, and summarizes the key

issues identified by members of the public during the initial scoping period. The top five

themes identified by members of the public include:

• Need for a greater influx of both freshwater and sediment to Terrebonne Parish

• Use of pipelines to distribute water and sediment

• Management of water flowing through the Gulf Intracoastal Waterway

• Need for freshwater flow into the Terrebonne marshes

• Impact to marshes from water increase and velocity

2.3 Problems, Needs, and Opportunities

The first step in the planning process is the identification of problems and opportunities.

Problems are undesirable, negative conditions that the study will address. Opportunities

are desirable conditions that could be achieved in the future. Study area problems and

opportunities were drawn from prior comprehensive planning studies and from public

input and inter-agency information exchange.

System-wide problems and opportunities were used to identify and define more

geographically specific problems and opportunities throughout the study area. Through

the NEPA public scoping process, the study team solicited input on problems and

opportunities from members of the public, government resource agencies, and other

stakeholders.

Conceptual Ecological Model

In order to better understand the problems, needs, and opportunities in the ARTM study

area, the PDT developed a conceptual ecological model (CEM). The CEM helped the

PDT understand drivers, stressors, and ecological effects in the study area, and, in turn,

helped the PDT identify the associated problems, needs, and opportunities. A summary

of the drivers, stressors, and ecological effects in the ARTM study area follows. A

graphic representation of the CEM can be found in Figure 2.1.

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Figure 2.1. ARTM Conceptual Ecological Model

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DRIVERS

Anthropogenic Alterations – Altered Hydrology

The central and eastern marshes of the study area do not receive adequate amounts of

fresh water or sediments from the Atchafalaya River (via the GIWW) or from the

Mississippi River (via Bayou Lafourche). Anthropogenic controls regulating the volume

of water entering the Atchafalaya River and Bayou Lafourche from the Mississippi River

in addition to the distance of the marshes from these potential sources of fresh water and

sediments limit the benefits to the central and eastern marshes. Consequently, subsidence

and sea level rise are outpacing accretion in most central and eastern marshes resulting in

increased submergence of marsh vegetation and eventual marsh loss. In addition, canals

and associated spoil banks constructed for navigation and/or oil and gas development can

be found throughout the study area. The canals serve as easy routes for fresh and

saltwater movement, serving as conduits for beneficial freshwater to escape the system

and for saltwater to enter the system. In addition, spoil banks compartmentalize

wetlands, restricting water and animal movement between areas.

Storms and Hurricanes

Coastal storms, particularly tropical cyclone events, exert a stochastic but severe

influence on the study area. Data obtained from the National Oceanic and Atmospheric

Administration (NOAA) Coastal Services Center indicate that the storm centers of at

least 19 tropical cyclones with a Saffir-Simpson Hurricane Scale of Category 2 or higher

have passed within 50 miles of the study area during the interval 1851-2008, and at least

31 such tropical cyclones have passed within 100 miles of the study area during the same

interval. The most recent tropical cyclones to affect the study area were Hurricanes

Katrina and Rita, which occurred in August 2005 and September 2005, respectively, and

Hurricanes Gustav and Ike, which occurred in September 2008.

Principal impacts to the marshes in the study area as a result of tropical cyclone events

are due to storm surge and associated erosion and saltwater intrusion. Storm surge exerts

widespread stress upon vegetation through the introduction of storm surge waters that

exhibit higher salinity concentrations than are normally present in surface waters within

the study area and by direct erosion of marsh plants and soils. Hurricanes Rita and Ike

resulted in measurable storm surges within the study area. Water gage data from the

Houma Navigation Canal indicate storm surges from Hurricanes Rita and Ike of

approximately 5.0 feet and 6.3 feet above average water levels, respectively.

Relative Sea Level Rise

Relative sea level rise consists of eustatic sea level rise combined with subsidence.

Eustatic sea level rise is defined as the global increase in oceanic water levels primarily

due to changes in the volume of major ice caps and glaciers, and expansion or contraction

of seawater in response to temperature changes. Baseline (i.e. recent) eustatic sea level

rise in the study area is approximately 0.75 feet/century. Subsidence is the decrease in

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land elevations, primarily due to consolidation of sediments, faulting, groundwater

depletion, and possibly oil and gas withdrawal. Subsidence in the study area is

approximately 2.35 feet/century. Relative sea level rise affects study area marshes by

gradually inundating marsh plants. Marsh soil surfaces must vertically accrete to keep

pace with the rate of relative sea level rise or marshes eventually convert to open water

due to the depth of submergence.

In summary, altered hydrology, sea level rise and subsidence, and periodic storm events

are the driving factors of land loss in the study area. The mechanisms of ecological stress

that result from these drivers and the impacts on study area marshes are detailed below.

ECOLOGICAL STRESSORS

Decreased Freshwater, Sediment, Nutrients, and Residence Time

The altered hydrology of the study area results in less freshwater and associated sediment

and nutrients being delivered to marsh vegetation. Lack of freshwater facilitates

increased saltwater intrusion and its associated effects on marsh vegetation. Vertical

accumulation of wetland soils is achieved by accretion of mineral sediment inputs and/or

organic accumulation resulting from above and below-ground plant productivity

(DeLaune et al. 1983a; DeLaune et al. 1990a). The survival and productivity of marshes

is reliant on these soil-building processes to offset submergence and sea level rise

(DeLaune et al. 1978; DeLaune et al. 1979; DeLaune et al. 1990b). As the natural

hydrology of the study area marshes has become short-circuited by canals, the residence

time of the limited freshwater inputs has also decreased. Shorter residence times result in

less settling of suspended sediments and less uptake of nutrients.

Increased Saltwater Intrusion

The altered hydrology of the study area facilitates increased saltwater intrusion and

increased tidal exchange by providing efficient conduits for loss of freshwater and

intrusion of saltwater. Wetland plant species have evolved different levels of tolerance to

salinity and respond to salinity with different mechanisms. Numerous studies have

demonstrated that elevated salinity can negatively affect all wetland species and can

contribute to large-scale vegetation dieback (Chabreck and Linscombe 1982; McKee and

Mendelssohn 1989). Storm surge can also be a mechanism for saltwater intrusion. This

form of saltwater intrusion can be particularly detrimental to areas that have been

hydraulically isolated, leading to extended durations of saltwater inundation.

Increased Erosion

Significant and immediate erosion of marsh vegetation and associated soils can occur as a

result of storm surge events. Losses may be more significant in areas that are already

under stress from other ecological stressors but healthy marsh systems can be

significantly impacted as well.

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In summary, decreased freshwater, sediment, nutrients and residence time, increased

saltwater intrusion, and erosion are the ecological stressors that exert the greatest

influence on study area marshes. The resultant ecological effects of these stressors are

detailed below.

ECOLOGICAL EFFECTS

Increased Submergence

Wetland plants employ different physical and/or metabolic mechanisms that enable them

to tolerate and grow in flooded soils. However, in almost all cases plants are dependent

on the maintenance of soil surface elevations to sustain the flooding regime to which they

are adapted. Increases in flooding depth and duration stress plants by altering metabolic

function and negatively impacting productivity, survival, and regeneration. Relative sea

level rise in the study area combined with insufficient accretion results in marsh systems

with reduced productivity, survival, and regeneration due to submergence. Organic

matter accumulation is also reduced, further exacerbating the impacts of submergence.

Decreased Wetland Health

Decreased freshwater, decreased nutrients, decreased residence time, increased saltwater

intrusion, and increased submergence all act to decrease the overall health of the study

area marshes. As marsh plants become stressed by inundation and saltwater intrusion,

their productivity, survival, and regeneration are all negatively impacted. Over time,

healthy marshes gradually decline to more interspersed marshes and eventually convert to

open water.

Increased Wetland Loss

Wetland loss in the study area can be the result of gradual decline of marsh vegetation

due to inundation and saltwater intrusion eventually leading to complete loss of marsh

vegetation or the result of storm surge events. As marsh vegetation is lost, underlying

soils are more susceptible to erosion and are typically lost as well, leading to deeper

water and precluding marsh regeneration. Significant accretion of sediments is then

required in order for marsh habitat to re-establish.

In summary, increased submergence of marsh plants and associated decreases in the

health of emergent marsh habitat result in the conversion of emergent marsh habitat to

open water. As area marshes convert to open water, vital fish and wildlife habitat,

economic benefits, and flood protection are lost.

2.3.1 General Problem Statement

Study Problem Statement. The natural processes of subsidence, habitat switching, and

erosion, combined with human activities, have caused significant adverse impacts to the

Northern Terrebonne Marshes, including accelerated wetland loss and ecosystem

degradation.

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In habitat switching, one habitat will convert to another habitat through succession. In

Louisiana, this process is frequently due to changes in salinity levels or inundation.

Examples of habitat switching may be a forested system converting to a freshwater marsh

or a freshwater marsh converting to a saline marsh. In the LCA-ARTM study area

habitat switching generally consists of switching from marsh habitat to open water. The

changes in habitat structure and/or composition result in a loss of one group of ecosystem

services and may result in local rarity of a habitat type.

Wetlands in the study area are deteriorating for several reasons: 1) subsidence and sea

level rise, 2) lack of sediment and nutrient deposition, 3) erosion via tidal exchange, 4)

channelization, and 5) saltwater intrusion. These activities have resulted in the loss of

several thousand acres of solid, vegetated marsh. Deterioration will continue unless

preventative measures are taken. With continued deterioration of the marshes, the area

landward will be more prone to flood during storm surges and hurricanes, as marshes

serve as partial flood barriers. Additionally, the marshes of the study area represent an

ecosystem of national importance from an environmental standpoint.

Adequate sediment exists in the Atchafalaya River to benefit marshes in the central and

eastern study areas; however, the existing and potential future sediment transport capacity

of the GIWW or channels and canals in the study area precludes adequate delivery of

sediments to achieve project goals and objectives.

In the absence of supplemental freshwater from the Atchafalaya River, subsidence, sealevel rise, wave erosion, and saltwater intrusion will continue to be problems. Protection

and enhancement of this area are dependent on providing a hydrologic regime that

minimizes the physiological stress to wetland vegetation from saltwater intrusion and

tidal energy and is conducive to the retention of locally provided freshwater and

sediments. Several channels have been dredged which cut through the natural ridges,

increasing both drainage and tidal exchange in the study area, exposing the soil to erosive

forces.

Major navigation channels in the subprovince are the Atchafalaya River, Wax Lake

Outlet, Houma Navigation Canal, GIWW, and Lower Atchafalaya River (south of

Morgan City). Each of these navigation channels introduces and/or compounds marine

influences in many of the interior coastal wetlands and water bodies within the

subprovince. Without action, the freshwater, intermediate, and brackish marshes in the

northern and eastern areas of Terrebonne Basin would continue to deteriorate and

disappear due to the combined effects of subsidence, saltwater intrusion, and a lack of

riverine influence. The flotant marshes within the Penchant Basin, located in northwest

Terrebonne Basin, would continue to deteriorate due to excessive backwater flooding

events from the Atchafalaya River. The marshes in the southern and eastern portions of

the study area would continue to deteriorate due to saltwater intrusion and a lack of

riverine influence.

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A detailed analysis of Existing Conditions and Future without Project Conditions in the

study area can be found in Chapters 4 and 5 of this report, respectively. Discussion of the

uncertainty in future relative sea level rise is discussed in section 3.10.2.

2.3.2 Study Area Opportunities

Opportunities exist to naturalize the distribution of freshwater and deltaic forming

sediments, improve hydrologic distribution of freshwater, improve topographic diversity

and reduce the negative impacts of Gulf storm events.

• Freshwater Supply – Re-introduction of freshwater supplies is an opportunity to

restore a degraded and impaired deltaic forming process. Further, freshwater

introduction has the potential to balance the altered salinity regime, improve the

viability of freshwater marsh plant life and therefore restore fish and wildlife habitats.

• Hydraulic Distribution – Human induced habitat fragmentation (canals) has resulted

in a degraded condition whereby the limited existing freshwater supplies are directed

through the Terrebonne Marshes and into the gulf. Opportunities exist to improve the

internal distribution of freshwater to restore and improve the sustainability of

freshwater marsh habitats.

• Sediment Supply and Distribution – The lack of marsh forming sediments from

riverine environments has accelerated the degradation of all marsh types.

Opportunities exist to re-introduce sediments from the Atchafalaya River and several

bayous and to use on site sediments displaced by gulf storm events to create new

marsh area.

• Sustainability – As marsh degradation has accelerated, seasonal gulf events have a

magnified impact on the remaining marsh areas. Opportunities exist through

freshwater supply and distribution and sediment supply and distribution to create a

healthier marsh which will be more resistant to the normal range of gulf events.

2.3.3 Problems, Future Without Project Conditions, and Opportunities by Study

Area Subunit

Due to the magnitude of the 1,100 square mile study area, the entire LCA-ARTM study

area was divided into three subunits, labeled as West - Bayou Penchant Area, Central -

Lake Boudreaux Area, and East - Grand Bayou Area. Subunits have been separated by a

combination of natural, physical, and geographic features, and the limits of the subunits

were developed by the PDT. The separation of the whole study area allowed the PDT to

evaluate specific needs and screen individual measures relative to each subunit.

Generally, all three study subunits are experiencing similar problems; wetlands are

deteriorating as a result of subsidence, lack of sediment and nutrient deposition, and

saltwater intrusion and erosion.

Although the GIWW has served as a major hydrologic alteration throughout the entire

study area, it also serves as a thread that connects all study units. Therefore, the GIWW

is considered as one of the primary opportunities to increase the delivery of freshwater,

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nutrients, and sediment to assist with marsh development and land building and

counteract the effects of saltwater intrusion and land subsidence.

When considering future without project conditions, the assumption was made that the

Morganza to the Gulf Project would be completed by 2025. The operating plan for the

Morganza to the Gulf HNC flood gates calls for closure of the flood gates whenever

necessary to prevent saltwater intrusion up the HNC. Accordingly, for purposes of future

without project hydraulic modeling, the assumption was made that the HNC flood gates

would be closed for two months each year starting in 2025. Other water control

structures associated with the Morganza to the Gulf Project would only be utilized under

tropical storm/hurricane conditions, and, therefore, would not appreciably impact the

hydrology of the study area under normal operating conditions. Therefore, these

structures were not included in the hydraulic modeling for the LCA-ARTM study.

West – Bayou Penchant Area

Problems –

Within the West – Bayou Penchant Area (Figure 2.2), problems include the lack of

freshwater, sediment, and nutrient delivery in the southern portions of the study area, land

loss, hydrologic alterations, subsidence, saltwater intrusion, constrictions in the GIWW,

and marsh break up along the GIWW. The study subunit problems have been

specifically identified as the following:

• Lack of freshwater, sediment, and nutrient delivery – Marsh die-back from lack of

freshwater, sediment, and nutrient delivery have been mostly observed in the southern

portions of the study area. The floating marshes located in the upper Penchant Basin

have been identified as not needing any additional freshwater, sediment, and nutrient

delivery.

• Subsidence and Land loss - In the lower Penchant Basin, significant wetland loss is

appearing in the triangle formed by Lost Lake, Lake Mechant, and Lake DeCade. In

this area, intermediate marshes are exposed to above normal salinity levels due to

subsidence and subsequent saltwater intrusion.

• Hydrologic alterations - The development of the GIWW, canals supporting oil and

gas industry, and the presence of pipelines have not only altered the delivery of

riverine flows, but have also promoted the increased delivery of saltwater to the study

subunit.

• Saltwater intrusion – This study subunit is currently not experiencing heavy saltwater

intrusion in the northern parts of the study subunit. However, marsh dieback from

increased saltwater influence has been observed and recorded in southern sections of

the Penchant Basin.

• Marsh Break up on the GIWW – Along the GIWW, wakes from passing ships/boats

cause the loss and breakup of floating marsh systems. Because of the breakup, the

GIWW has widened beyond its originally authorized configuration in many locations.

Due to the high organic content of floating marsh systems, the soils along the GIWW

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are very soft and fluid, providing a unique and complex set of circumstances which

make the implementation of hard shoreline stabilization measures difficult.

• GIWW Constrictions – Between Bayou Black and Bay Wallace, the GIWW narrows

and flow is constricted. At this location, the GIWW flows through a high quality

forested wetland system that is dominated by a cypress-tupelo overstory. This

constriction lessens flow to the central and eastern parts of the study area.

Future Without Project Conditions

Land loss/gain trends (Figure 2.3) within the West – Bayou Penchant Area are expected

to continue through the period of analysis. Land loss analysis indicates that most of the

flotant marshes in the northwestern portions of the sub-area are expected to remain stable

or show some gains in land area. Land change projections over the period of analysis

show increases in land area of approximately 12,400 acres, or roughly 5%. However,

land loss analysis in this area is particularly difficult due to the presence of floating

vegetation. It is believed by personnel familiar with the area that these marshes are

actually deteriorating due to excessive backwater flooding events from the Atchafalaya

River and will continue as such into the future. Modeled salinity values show no change

over the period of analysis. The intermediate and brackish marshes in the southeastern

portion of the sub-area are expected to continue to deteriorate due to saltwater intrusion,

relative sea level rise, and lack of freshwater, sediment and nutrient delivery. Modeled

average annual salinity values show slight increases of 0.1 to 0.4 ppt over the period of

analysis. Land change projections over the period of analysis show decreases in land

area of approximately 19,800 acres, or roughly 35%. Overall, the entire West – Bayou

Penchant Area is projected to lose approximately 7,400 acres of land from 2015 to 2065,

or approximately 2%. However, this number does not accurately reflect the true

magnitude of land loss in the area due to the analysis problems mentioned above.

Opportunities –

Within this study area, opportunities to implement restoration measures include creating a

diversion from the Atchafalaya River. The goal of the diversion would be to increase

freshwater, sediment, and nutrient supply to the study area, but the results of the

diversion may be more heavily relied on in study units east of the West – Bayou Penchant

Area.

In combination with increasing supply of riverine water into the GIWW, other methods to

improve delivery and distribution of freshwater include enlarging constrictions within the

GIWW and improving eastward conveyance along the GIWW. As noted in the

problems, an observable constriction within this study unit is in a location where the

GIWW flows through a high-quality, forested wetland system, located between Bayou

Black and Bay Wallace. Opening this constriction may assist with increasing flow to the

study area, as well as the other two eastern study areas. There are also many points along

the GIWW where canals serve as diversion points for freshwater, thus affecting the

quantity of freshwater conveyed east of Houma.

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Another opportunity to improve eastward conveyance of riverine water and reduce marsh

break up involves methods to stabilize critical lengths of deteriorated channel banks

along the GIWW and Bayou Chene. Bank protection within this study unit is anticipated

to diminish the effects of wave wash from vessels and reduce breakup. Bank

stabilization is also an opportunity to restrict the number of openings and routes where

freshwater supply is escaping to wetlands that are nutrient and sediment rich. Locations

along Bayou Chene near Avoca Island and areas along the GIWW east of Bay Wallace

will likely require measures of protection. Combined with bank stabilization, nonstructural methods to manage navigation traffic may be appropriate.

Within the southern portions of the study area, opportunities to increase freshwater

delivery and sediment input are available and needed. The options of implementing

additional freshwater diversions in the Lower Penchant Basin may be necessary to reduce

the problem of deteriorating wetlands and land loss in locations between Lost Lake, Lake

Mechant, and Lake DeCade. This area seems to be most hard hit from land subsidence,

saltwater intrusion, and marsh loss. Other methods to diminish the influence of saltwater

in the Lower Penchant Basin involve implementing strategic land building to create new

ridges to assist with the redistribution of flow and minimize the influence of saltwater.

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Figure 2.2. West - Bayou Penchant Sub Area.

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Figure 2.3. Land Gain/Loss Rates in the Study Area. Percent per year based on 1985 to 2008 rates and 1985 acreage. (Based on Barras et al 2008 and Barras 2009). Negative Numbers indicate land loss.

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Central - Lake Boudreaux Area

Problems –

Within the Central – Lake Boudreaux Area (Figure 2.4), problems include lack of

freshwater, sediment, and nutrient delivery, land loss, hydrologic alterations, subsidence,

saltwater intrusion, constrictions in the GIWW, and area infrastructure. The study

subunit problems have been specifically identified as the following:

• Lack of freshwater, sediment, and nutrient delivery – Marsh die-back from lack of

freshwater, sediment, and nutrient delivery has been observed in many locations

within the study subunit. Freshwater delivered to the HNC bypasses adjacent

wetlands and is more efficiently delivered to the Gulf of Mexico.

• Subsidence and Land loss - In this study subunit, significant land loss is appearing

along both sides of the HNC, especially in areas south of Lake Boudreaux. In this

area, marshes are exposed to above normal salinity levels due to subsidence and

subsequent saltwater intrusion.

• Hydrologic alterations – The development of the HNC and man-made canals have not

only altered the delivery of riverine flows, but have also promoted the increased

delivery of saltwater to the study subunit.

• Saltwater intrusion – Due to the “short circuiting” effects produced by the

construction and maintenance of the HNC, saltwater intrusion along the lengths of the

canal have become increasingly problematic. The HNC provides an unrestricted

route for easy transport of saltwater to move into areas that have historically been

fresh and intermediate marshes.

• GIWW Constrictions - There are major hard constrictions in the GIWW within the

City of Houma. These hard constrictions prevent desired conveyance through the

GIWW to the eastern part of the Central – Lake Boudreaux Area subunit and to the

East – Grand Bayou Subunit.

• Area infrastructure – This study subunit contains portions of the City of Houma, as

well as area infrastructure associated with shipping, oil and gas industry, residential

and commercial development within Houma and along Bayou Grand Caillou, Bayou

Petit Caillou, and Bayou Terrebonne.

Future Without Project Conditions

Land loss/gain trends (Figure 2.3) within the Central – Lake Boudreaux Area are

expected to continue through the period of analysis. Areas in the northern portion of the

sub-area that exhibit little land loss are largely developed or agricultural areas and are

anticipated to remain as such and maintain current land areas. The fresh, intermediate,

brackish, and saline marshes in the central and southern portions of the sub-area and in

areas just south of the sub-area are expected to continue to deteriorate due to saltwater

intrusion, relative sea level rise, and lack of freshwater, sediment and nutrient delivery.

Modeled average annual salinity values show increases of 0.3 to 1.2 ppt over the period

of analysis. Land change projections over the period of analysis show decreases in land

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area of approximately 44,000 acres, or approximately 35%, from 2015 to 2065, with

several areas converting completely to open water.

Opportunities –

Within this study area, restoration and protection measures aimed at maintaining the

physical integrity of the area primarily include a transition toward a greater riverine

influence to deliver freshwater, sediments, and nutrients to help promote healthier marsh

system and lower salinity levels. Opportunities to implement restoration measures

include increasing delivery of freshwater to the study subunit through the GIWW and

into the HNC. Through the increased supply of freshwater, sediments, and nutrients,

diversions may be implemented off the HNC through either gated structures or canals to

nearby wetlands. Diversion locations were evaluated in areas on both the eastern and

western side of the HNC.

In combination with increasing freshwater supply into the GIWW, other opportunities to

improve delivery and distribution to the study area may include enlarging constrictions

within the GIWW. An observable constriction within this study unit is within the City of

Houma, Louisiana. Opportunities to open constrictions will be difficult due to the area

infrastructure. Opening this constriction may assist with increasing flow to the

immediate study area through Bayou Petit Caillou and Bayou Terrebonne. However,

widening the constriction will also serve the purpose of continued conveyance to the

eastern study subunit.

Another opportunity to improve retention of fresh water and diminish the influence of

saltwater intrusion is to consider management of the proposed HNC lock complex and

the proposed Morganza to the Gulf Levee. The design and management of the planned

HNC Lock/Morganza to the Gulf levee may provide both environmental and flood

control benefits. The lock complex and floodgate can be managed to assist with salt

water intrusion and freshwater distribution. Other methods involve implementing

strategic land building south of Lake Boudreaux to assist with the retention of freshwater

and diminish the influence of saltwater.

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Figure 2.4. Central - Lake Boudreaux Sub Area.

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East - Grand Bayou Area

Problems –

Within the East – Grand Bayou Area (Figure 2.5), problems include lack of freshwater,

sediment, and nutrient delivery, land loss, hydrologic alterations, subsidence, and

saltwater intrusion. The study subunit problems have been specifically identified as the

following:

• Lack of freshwater, sediment, and nutrient delivery – Marsh die-back from lack of

freshwater, sediment, and nutrient delivery have been observed in many locations

within the study subunit. Freshwater delivered to Grand Bayou Canal bypasses

adjacent wetlands and is efficiently routed to the Gulf of Mexico.

• Subsidence and Land loss – Of the three study subunits, this subunit is experiencing

the greatest amount of land loss. Salt sensitive wetlands have suffered substantial

deterioration and loss within this watershed. Losses can be attributed to the lack of

freshwater, sediment, and nutrient delivery, historic sulphur mining activities, and the

construction of numerous oil and gas canals. South of Bayou Blue, freshwater

wetlands quickly turn to open-water ecosystems due to extensive marsh dieback.

• Hydrologic alterations – The study subunit contains numerous hydrologic alterations.

The channelizing of Grand Bayou to create Grand Bayou Canal and the dredging of

Cutoff Canal provides an unrestricted channel of saltwater to the area. From Grand

Bayou Canal, saltwater continues to intrude through the network of canals, pipeline

routes, and abandoned mines.

• Saltwater intrusion – Due to the “short circuiting” effects produced by the

construction and maintenance of Grand Bayou Canal and Cutoff Canal, saltwater

intrusion seems to be the most problematic within this study subunit. Grand Bayou

Canal provides an unrestricted route for easy transport of saltwater to move into areas

that have historically been fresh and intermediate marshes.

• Area infrastructure – This study subunit contains area infrastructure associated

with residential and commercial development, and infrastructure tied to oil and

gas industries.

Future Without Project Conditions

Land loss/gain trends (Figure 2.3) within the East – Grand Bayou Area are expected to

continue through the period of analysis. The fresh, intermediate, brackish, and saline

marshes in the central and southern portions of the sub-area and in areas just south of the

sub-area are expected to continue to deteriorate due to saltwater intrusion, relative sea

level rise, and lack of freshwater, sediment and nutrient delivery. Modeled average

annual salinity values show increases of 0.1 to 1.7 ppt over the period of analysis. Land

change projections over the period of analysis show decreases in land area of

approximately 44,000 acres, or approximately 49%, from 2015 to 2065, with several

areas converting completely to open water.

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Opportunities –

Within this study area, restoration and protection measures aimed at maintaining the

physical integrity of the area primarily include a transition toward a greater riverine

influence and creating barriers to saltwater intrusion. Opportunities to implement

restoration measures include increasing freshwater, sediment, and nutrient supply and

delivery to the study subunit through increasing freshwater supply from the Atchafalaya

River and/or implementing other diversions that utilize the Mississippi River as a

freshwater source. Additional diversions from the Mississippi River could either

supplement or provide freshwater in lieu of a diversion from the Atchafalaya River.

Diversions were considered from locations outside the study area, which include a

diversion from the Mississippi River into Bayou Lafourche near the City of

Donaldsonville, Louisiana or utilizing the increased freshwater supply planned through

the LCA Davis Pond Diversion project. Once freshwater supply is increased to the study

area and delivered to Grand Bayou Canal, diversions off of Grand Bayou Canal may

offer solutions to increase freshwater, sediment, and nutrient delivery to wetlands located

within this study subunit.

Another opportunity to improve retention of fresh water and diminish the influence of

saltwater intrusion is to consider planned construction of the proposed Morganza to the

Gulf Levee. The design of the Morganza to the Gulf levee may provide both

environmental and flood control benefits. However, this levee would not encapsulate the

entire study subunit, and additional methods to minimize saltwater intrusion and help

retain freshwater within the remaining portions of the study subunit would likely be

necessary. Within the southern limits of the study area, other methods to assist with

freshwater retention and provide a saltwater barrier involve implementing strategic ridge

development and outfall management along the boundary line of the study area and near

the north side of Terrebonne Bay.

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Figure 2.5. East - Grand Bayou Sub Area.

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2.4 Planning Objectives

Study goals, objectives, and constraints were developed to comply with the study

authority and to respond to study area problems and opportunities.

2.4.1 Goals

Reduce the current trend of degradation of the Terrebonne marshes, so as to contribute

towards achieving and sustaining a coastal ecosystem that can support and protect the

environment, economy, and culture of southern Louisiana and thus the Nation.

2.4.2 Objectives

The objective of the study is to formulate a project to provide additional freshwater,

nutrients, and fine sediment to the area. The introduction of additional freshwater could

facilitate organic sediment deposition, improve biological productivity, and prevent

further deterioration of the marshes. Specific project objectives include, but are not

limited to the following and are applicable to all three sub-unit areas:

• Prevent, reduce, and/or reverse future wetland loss

• Achieve and maintain characteristics of sustainable marsh hydrology

• Reduce salinity levels in project area

• Increase sediment and nutrient load to surrounding wetlands

• Increase residence time of fresh water

• Sustain productive fish and wildlife habitat

2.5 Planning Constraints

2.5.1 Constraints

Development and evaluation of restoration alternatives for the proposed project are

constrained by a number of factors. These factors are generally divided into two

categories:

• Project design constraints- Limitations to the scope and functionality of specific

project features because of issues regarding project effects on other projects or

infrastructure in the study area; and

• Ecosystem constraints- Constraints imposed upon the project design by existing

conditions within the study area’s ecosystem

These categories and their constituent constraints are discussed separately below.

Project Design Constraints. Identified project design constraints for the LCA-ARTM

project include the following:

• Flood Damage Protection. The LCA-ARTM project must accomplish its goals

while avoiding elevating flood levels at nearby communities.

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• The LCA-ARTM project must protect vital socioeconomic resources including

cultures, community, infrastructure, business and industry, and flood protection.

• Some existing infrastructure such as navigation locks and the constrictions of the

GIWW could need modification to accommodate flow regimes that support the

objectives of the LCA-ARTM project. Some of these constrictions and

navigation features cannot be modified due to urban development in Houma, the

need to maintain the GIWW for navigation, or exorbitant costs of constriction

removal.

• A substantial amount of oil and gas infrastructure exists within the study area.

Adverse effects to oil and gas infrastructure would be minimized to the extent

practicable, consistent with the goals of the project.

• Drainage Infrastructure. The internal arrangement of small access canals would

likely need to be altered to support the goals of the project. This would have to be

done in a manner that would allow reasonable access to all prospective users.

Figures 2.6 and 2.7 identify the flow patterns and drainage constrictions in both

the Western and Eastern Study Areas.

Figure 2.6. Flows and Constrictions in the Western Study Area

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Figure 2.7. Flows and Constrictions in the Eastern Study Area

Ecosystem Constraints. Identified ecosystem constraints for the LCA-ARTM project

include the following:

• Water Quality – The introduction of water and sediments should not result in the

violation of established water quality standards in the study area.

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3.0 ALTERNATIVES

3.1 Plan Formulation Rationale

3.1.1 Plan Formulation Rationale

Alternatives for the proposed action were formulated in consideration of study area

problems and opportunities, as well as study goals, objectives and constraints. For

discussion of the six-step planning process see Section 1.6 above. As specified in ER

1105-2-100, four criteria were considered during alternative plan screening:

completeness, effectiveness, efficiency, and acceptability.

3.1.2 Plan Formulation Criteria

3.1.2.1 Completeness

Completeness is the extent that an alternative provides and accounts for all investments

and actions required to ensure the planned output is achieved. This may require that an

alternative consider the relationship of the plan to other public and private plans if those

plans affect the outcome of the project. Completeness also includes consideration of real

estate issues, O&M, monitoring, and sponsorship factors. Adaptive management plans

formulated to address project uncertainties also have to be considered.

3.1.2.2 Effectiveness

Effectiveness is defined as the degree to which the plan will achieve the planning

objective. The plan must make a significant contribution to the problem or opportunity

being addressed.

3.1.2.3 Efficiency

The project must be a cost-effective means of addressing the problem or opportunity.

The plan outputs cannot be produced more cost-effectively by another institution or

agency.

3.1.2.4 Acceptability

A plan must be acceptable to Federal, state, and local government in terms of applicable

laws, regulations, and public policy. The project should have evidence of broad-based

public support and be acceptable to the non-Federal cost sharing partner.

Environmental Operating Principles

In 2002, the USACE formalized a set of Environmental Operating Principles applicable

to decision-making in all programs. The principles are consistent with NEPA; the Army

Strategy for the Environment; other environmental statutes, and the WRDAs that govern

USACE activities. The Environmental Operating Principles inform the plan formulation

process and are integrated into all project management processes. Alternatives were

formulated for this study consistent with the Environmental Operating Principles.

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The USACE Environmental Operating Principles are:

• Strive to achieve environmental sustainability, and recognize that an environment

maintained in a healthy, diverse, and sustainable condition is necessary to support

life;

• Recognize the interdependence of life and the physical environment, and

proactively consider environmental consequences of USACE programs and act

accordingly in all appropriate circumstances;

• Seek balance and synergy among human development activities and natural

systems by designing economic and environmental solutions that support and

reinforce one another;

• Continue to accept corporate responsibility and accountability under the law for

activities and decisions under our control that impact human health and welfare

and the continued viability of natural systems;

• Seek ways and means to assess and mitigate cumulative impacts to the

environment and bring systems approaches to the full life cycle of our processes

and work;

• Build and share an integrated scientific, economic, and social knowledge base that

supports a greater understanding of the environment and impacts of our work; and

• Respect the views of individuals and groups interested in USACE activities, listen

to them actively, and learn from their perspective in the search to find innovative

win-win solutions to the Nation’s problems that also protect and enhance the

environment.

3.1.3 LCA ARTM Study Area Land Loss

The loss of coastal marsh within the LCA-ARTM study area has been profound. In order

to quantify land loss in the study area, determine existing and likely future conditions,

and facilitate determination of project impacts on area marshes, habitat and land loss

analyses were conducted on the study area. The area was broken up into 65 polygons,

with habitat classification and land loss analysis conducted on each. In order to

determine the rate of land loss or land gain within each of the polygons, imagery from

1985 to 2008 was utilized (Table 3.1). Imagery was analyzed to determine percent

coverage of land and water for each year that imagery was available. These data points

were then used to determine land area trend lines for each polygon and for the study area

as a whole (Figure 3.1). The overall current rate of land loss in the study area was

determined to be approximately 2,500 acres/year (approximately 0.3 percent per year).

However, as can be seen in Figure 3.2, there is considerable variation from polygon to

polygon in the rate of land loss or land gain. In general, the areas with the highest rates

of land loss are the intermediate, brackish, and saline marshes in the southern and eastern

sections of the study area. The swamp and fresh marsh habitats generally are exhibiting

lower rates of land loss and in some cases land gain.

For future without project condition determination, the current rate of land loss within

each polygon was assumed to continue on a linear trend over the 50-year period of

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analysis. For some polygons, this resulted in complete conversion to open water before

the end of the period of analysis. Over the entire study area, approximately 100,000 acres

of marsh were projected to be lost between 2015 and 2065. The future loss rate for the

study area is what the PDT in partnership with the sponsor and the public set goals and

objectives against and ultimately measured action alternatives against to determine

relative benefits.

Loss of marsh habitat in the study area is caused by a variety of one time or short term

events and by the alteration of systemic marsh building processes. Contributors to marsh

conversion include:

• Gas and Oil Pipeline Construction

• Extreme 2005 Gulf Storm Events

• Altered Deltaic Processes

o Subsidence

o Diminished Sediment Inputs

o Diminished Fresh Water Inputs

o Diminished Nutrient Inputs

• Sea Level Rise

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Table 3.1. Study Area Land Loss based on USGS imagery analysis.1 Incomplete data in study area for 1956 and 1978 imagery. 1985 to 2008 imagery was used in calculation of land loss trend lines based on USGS

recommendation for improving accuracy of projections.

2 Variations in calculated land area from year to year occur due to actual land loss and land gain, major storm events, differing tides/water elevations

on the dates imagery was captured, random variation, etc. Trend lines over longer periods of time provide a more accurate picture of actual land losstrends than comparing individual years (see Figure 3.1).

Date Land Area2 (acres) Water (acres) Total (acres) Land Area (mi2) Water (mi2) Total (mi2) % Land % Water

19561 619,822 119,254 739,076 968.5 186.3 1154.8 83.9% 16.1%19781 517,010 223,044 740,054 807.8 348.5 1156.3 69.9% 30.1%

1/9/1985 613,936 285,211 899,147 959.3 445.6 1404.9 68.3% 31.7%

1/28/1988 651,841 247,306 899,147 1018.5 386.4 1404.9 72.5% 27.5%

1988 649,064 250,083 899,147 1014.2 390.8 1404.9 72.2% 27.8%

11/1/1990 627,223 271,924 899,147 980.0 424.9 1404.9 69.8% 30.2%2/24/1998 582,939 316,208 899,147 910.8 494.1 1404.9 64.8% 35.2%

11/18/1999 602,428 296,719 899,147 941.3 463.6 1404.9 67.0% 33.0%

10/1/2000 579,684 319,463 899,147 905.8 499.2 1404.9 64.5% 35.5%

10/30/2001 597,316 301,831 899,147 933.3 471.6 1404.9 66.4% 33.6%

2/27/2002 599,453 299,694 899,147 936.6 468.3 1404.9 66.7% 33.3%11/7/2004 595,262 303,885 899,147 930.1 474.8 1404.9 66.2% 33.8%

10/25/2005 585,852 313,295 899,147 915.4 489.5 1404.9 65.2% 34.8%10/28/2006 583,483 315,664 899,147 911.7 493.2 1404.9 64.9% 35.1%

10/1/2008 576,400 322,747 899,147 900.6 504.3 1404.9 64.1% 35.9%

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Figure 3.1. Calculated study area land loss rate (1985-2008).

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Figure 3.2. Land Gain/Loss Rates in the Study Area – percent per year based on 1985 to 2008 rates and 1985 acreage (based on Barras et al. 2008 and Barras2009). Negative numbers indicate land loss.

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3.2 Management Measures

The Corps guidance defines a management measure as a feature (a structural element that

requires construction or assembly on-site) or an activity (a nonstructural action) that can be

implemented at a specific geographic site to address one or more planning objectives and utilize

opportunities (USACE 2000). Management measures can be combined to form alternative plans.

Measures can be derived from a variety of sources including prior studies, the NEPA public

scoping process, and the multidisciplinary, interagency project delivery team (PDT). For this

study, the PDT consisted of individuals from U.S. Fish and Wildlife Service, Natural Resources

Conservation Service, National Marine Fisheries Service, U.S. Geological Survey, U.S.

Environmental Protection Agency, Louisiana Coastal Protection and Restoration Authority,

Louisiana Department of Wildlife and Fisheries, and the U.S. Army Corps of Engineers

3.2.1 Development of Management Measures

Before alternative plans were formulated, the first step taken was to identify potential

improvements that would satisfy the goals and objectives established for the study area. From

these discussions, the interagency PDT developed an array of general measures for the study

area, from which specific measures would be developed. The PDT’s depth of professional

experience and first-hand management knowledge was invaluable in identifying and defining

general measures. The general measures were then evaluated for their ability to produce positive

benefits for nine screening criteria developed by the PDT. The measures that passed the

evaluation process were carried forward as possibilities for inclusion into study alternatives.

Some measures included in study alternatives came directly from CWPPRA projects (see Table

3.5). Only measures from CWPPRA projects that had not been approved for construction

funding, and therefore were not considered to be part of the future without project condition,

were considered for inclusion in the LCA-ARTM study. Since there was no certainty that these

measures would be implemented under CWPPRA, and since many of the CWPPRA measures

are aimed at achieving the same objectives as the LCA-ARTM study, it was logical to utilize

CWPPRA measures where appropriate in LCA-ARTM plan formulation.

3.2.2 Description of Management Measures

General measures have been loosely separated in six categories that seek to address the study

goals and objectives under the current authorization. The following list of general measures was

developed:

Freshwater Supply and Distribution - Due to canal construction and levee impacts, many areas

of existing marsh do not receive adequate freshwater.

• Freshwater Distribution Channel - Freshwater distribution channels would improve

freshwater, sediment, and nutrient delivery to selected locations. Freshwater delivery

systems may be constructed as channels extending from a variety of existing freshwater

sources.

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• Gated Diversion Structure - Gated structures can control freshwater supply and prevent

saltwater intrusion to select locations or the entire study area. The structures can be

operated manually or electronically using a controlled gated system. Gated systems can

pass flows ranging from 5,000 to 100,000 cubic feet per second.

• Groundwater for Freshwater - Groundwater could be used as a source of freshwater by

drilling wells and pumping water into marshes

• Culverts - Culverts would be placed in strategic locations (e.g. through roadways, ridges,

or dredged material embankments locally known as spoil banks) to distribute freshwater.

• Outfall and Distribution Management - Existing canals for gas, oil and utilities alter the

distribution of freshwater and increase the exposure of some marshes to saltwater

intrusion and Gulf storm damage. Existing canals could be altered to redistribute flows.

Alterations could include cutting spoil banks to facilitate sheet flow, filling man-made

canals to reduce freshwater bypass of marshes, and placing weirs in channels to create a

baffle effect to slow the intrusion of saltwater and increase freshwater residence time.

• Open Constrictions to Water Transport – Channel constrictions reduce the channel’s

flow capacity and thus slow the delivery of freshwater, sediments, and nutrients.

Modifying existing constrictions can aid water delivery.

• Operation of Houma Navigation Canal Lock - The operation of the proposed Houma

Navigation Canal lock complex is primarily a function of vehicle transportation and

hurricane and storm damage reduction. However, the lock complex could serve a

multipurpose function to help retain and redistribute freshwater throughout the

Terrebonne marshes. It could also assist with reducing saltwater intrusion.

Sediment Supply and Distribution for Mechanical Marsh Creation

• Canal Dredging and Placement - Canals that are needed to support commerce but that

have filled with sediment could be dredged to improve freshwater circulation. The

dredged material would be placed in pockets of open water in adjacent marshes, thereby

decreasing marsh fragmentation and increasing overall marsh acreage.

• Dredging and Placement of Regional Sediments - This measure entails large scale

importation of suitable riverine sediments from dredging nearby portions of the

Mississippi River or Atchafalaya River. Dredging and placement could be done

mechanically and/or hydraulically.

• Sediment Delivery from Distant Sources - The large quantities of sediment required for

holistic marsh habitat restoration in the area could justify large scale sediment

importation from areas beyond the immediate study area. Existing abandoned pipelines

could be used to import sediment using pipelines and booster pumps. Alternatively,

sediment could be moved from more distant sediment laden rivers (e.g. Illinois or

Missouri River) using suitable transportation.

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Restore/Maintain Historic Geomorphic Features

• Construct Ridges to Create Marsh - Along freshwater marsh edges, construct ridges to

help prevent saltwater intrusion and slow freshwater movement. This could include flow

control structures in the ridges. The slightly higher elevations of constructed ridges could

provide niche habitats as well as improve the short term sustainability of existing ridges.

• Bank and Shoreline Protection - Where high quality marsh exists, bank protection could

be provided to diminish wave wash effects from vessels and/or to reduce marsh

degradation due to storm surge.

Invasive Species Management - These measures would likely be combined with other measures

to improve overall habitat quality.

• Eradication Program for Nutria - Nutria are large semi-aquatic rodents introduced to

Louisiana from South America to enhance the fur trade industry. Since the decline of fur

trading, nutria has become abundant putting pressure on marsh vegetation. Control

measures proposed include incentivizing nutria removal through hunting and trapping to

promote vegetation re-growth.

• Control of Water Hyacinth - This non-native floating plant competes with native

vegetation for nutrients and clogs structures and channels slowing freshwater delivery.

Chemical or mechanical methods could be used to remove and control water hyacinth.

Navigation Management

• Create “No Wake” Zones or Develop Speed Restrictions - Wave wash from vessels

erodes bank lines and damages marsh along large channels. Vessel management

programs can create “No Wake” zones or develop speed restrictions near areas of fragile

marsh. These restrictions could be permanent or only during periods of higher water.

• Traffic Management through Scheduling – An operation plan to schedule vessel

movement, specifically on the Houma Navigation Canal, could assist the environmental

operation of structures such as the lock.

Vegetation Management

• Reestablish Marsh in Target Areas by Planting – Marsh could be reestablished by

transplanting vegetative plugs from healthy marshes in the area.

3.2.3 Screening / Evaluation of Alternative Plans

Screening of measures is a process where a measure’s ability to meet various criteria is evaluated

to better characterize a specific measure and the likelihood that it can achieve cost effective

restoration. The outcome of this process can result in measures being dropped from further

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consideration.

Nine screening criteria were agreed upon by the interagency PDT. The selected criteria were

chosen based upon experience with previous and concurrent restoration efforts in the study area,

knowledge of the study area, conventional scientific theory, best professional judgment, and

consideration of study objectives. The PDT further separated the nine criteria into two tiers (see

below) with the first tier taking priority over the second tier. The PDT then determined that the

measure’s ability to meet the criteria would be evaluated for each individual subunit, West –

Bayou Penchant, Central – Lake Boudreaux Area, and East – Grand Bayou Area (Fig. 2.2-2.5).

For each of the nine screening criteria, the PDT 1) determined if the measure would likely

produce a positive net benefit represented by a plus (+) sign, 2) determined if the measure would

not likely produce a positive net benefit within the screening category, represented as a minus (-)

or 3) made an unknown determination of the measure’s net benefit, represented as a zero (0). If

the measure was considered as not being applicable to the study unit, a designation of N/A was

applied and this measure was considered for elimination.

First Tier – Screening Criteria - If a measure received “-” marks for two of the four criteria

below, then the measure was considered for elimination (Table 3.2).

• Achievement of Planning Objectives - The measure can support one or all of the

ecosystem objectives for this study. The more objectives supported, the more holistic the

solution.

• Synergy with other state/Federal projects – The measure works in conjunction with other

state and Federal programs and projects aimed at marsh restoration. The PDT used their

extensive knowledge of the project area to evaluate if the level of marsh restoration

provided by a measure would be greater because of the effects of other programs and

projects in the area.

• O&M Requirements – The measure is relatively simple and inexpensive to operate and

maintain. Due to the remote nature of the study area, a measure that is simple and

inexpensive to operate is more likely to be operated correctly. The team felt that this

criterion was important because correct operation is critical to marsh restoration success.

• Efficiency of Delivery – Measures have variable timeframes for creating acreage of new

habitat and positively impacting existing marsh from immediate to long term. Without

the restoration, sea level rise, storm events, and marsh degradation could eventually

eliminate coastal marshes in the study area. Measures that could quickly produce

additional marsh or slow/prevent degradation would likely produce positive benefits (+).

Measures that required a long timeframe to produce benefits would not likely produce

positive benefits (-) because study area coastal marshes may no longer exist.

Second Tier – Screening Criteria – These criteria were developed to evaluate the potential for

each measure to cause consequential damages in excess of the authorized project cost and violate

environmental laws. If the measure passed the first tier of screening, under the second tier, if it

received two “-” marks, then the measure was considered for elimination (Table 3.2).

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• Infrastructure Impacts – The study area contains a network of oil and gas infrastructure

consisting of pipelines and wells, as well as local municipal infrastructure. The

measures’ impacts on infrastructure were considered.

• T/E Species – Each measure was evaluated to determine whether it would have a

potential negative effect on any state or Federal Listed Threatened/Endangered species.

• Wetland Impacts - Each measure was evaluated on net wetland loss during construction.

• Flooding - Measures that have the potential to induce flooding on existing developed

areas were identified

• Navigation - Measures that have the potential to introduce navigational hazards or

increase operations and maintenance costs were identified.

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Table 3.2 Screening Criteria.The general measures developed by the PDT were evaluated for their ability to provide positive benefits (+), not provide positive benefits (-) or benefit production was unknown (0) or the measure was not applicable (n/a).Not applicable measures and measures whose “-“ criteria value are outlined were considered for elimination for: West – Bayou Penchant Area, Central – Lake Boudreaux Area, East – Grand Bayou Area

First Tier Screening Criteria Second Tier Screening Criteria

Goals & Obj.

Achievement

Synergy with Other

Programs

O&M

Requirements Efficiency Infrastructure Impacts T/E Species Wetland Impacts Flooding Navigation

Measures West

Central

East

West

Central

East

West

Central

East

West

Central

East

West

Central

East

West

Central

East

West

Central

East

West

Central

East

West

Central

East

Freshwater Supply and Distribution 0 0 0Freshwater Distribution Channels + + + + + + + + + 0 0 0 0 0 0 + + + + + + +++ 000Gated Diversion Structures + 0 0 + 0 0 - - - + 0 0 - - - 0 0 0 + + + 0 0 0 0 0 0Groundwater for Freshwater - - - - - - - - - - - - 0 0 0 + + + + + + +++ 000Culverts 0 0 0 0 0 0 0 0 0 0 0 0 + + + 0 0 0 + + + + + + 0 0 0Outfall and Distribution Management + + + + + + + + + + + + 0 0 0 + + + + + + +++ 000Open Constrictions to Water Transport + + + + + + + + + + + + 0 0 0 + + + 0 0 0 + + + 0 0 0Management of H.N.C. Lock 0 + + + + + - - - 0++ + 0 + 0 0 0 + + + 000 n/a - n/aSediment Supply and DistributionCanal Dredging and Placement + + + + + + + + + 0 0 0 + + + + + + + + + +++ +++Dredging and Placement of Regional Sediments + + + + + + 0 0 0 - - - + + + + + + + + + + + + + + +Sediment Delivery from Distant Sources + + + 0 0 0 0 0 0 - - - 0 0 0 + + + + + + 000 000Restore/Maintain Historic GeomorphicFeaturesConstruct Ridges to Create Marsh + + + + + + - - - 0 0 0 0 0 0 + + + + + + 000 00 -Bank and Shoreline Protection + + + + + + - - - + + + 0 0 0 + + + + + + + + + 0 0 0Invasive Species ControlEradication Program for Nutria 0 0 0 + + + - - - + + + + + + + + + + + + +++ 000Control of Water Hyacinth n/a + + n/a + + n/a - - n/a 0 0 + + + + + + + + + + + + + + +Navigation ManagementCreate “No Wake” Zones + n/a n/a + n/a n/a + n/a n/a + n/a n/a - - - + + + + + + + + + ---Traffic Management - Scheduling n/a + n/a n/a - n/a n/a + n/a n/a + n/a + + + + + + + + + + + + + + +Vegetation ManagementTarget Area Planting + + + + + + 0 0 0 0 0 0 + + + + + + + + + +++ 000

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The First Tier screening process resulted in one measure being considered for removal from all

subunits (Table 3.2). The Second Tier screening process also resulted in one measure being

considered for removal. There were two additional measures that were determined to be not

applicable to certain study units and were considered for elimination (Table 3.2). The PDT

found the evaluation of measures difficult because the hydrologic modeling and WVA

assessments had not been completed. However, screening was needed to assist with the

reduction of the number of measures.

Measures considered for elimination were further evaluated by the PDT to determine if they

could provide a valuable contribution to the project separately or in combination with other

measures.

3.2.4 Measures Not Carried Forward for Further Analysis

After completing the screening process, the measures considered for elimination were evaluated

by the PDT. The PDT determined that these measures could not provide a valuable contribution

to the project alone or in combination with other measures. Therefore, the following measures

were eliminated as discussed below.

The following measures were eliminated from further consideration in all subunits:

Dredging and Placement of Regional Sediments – This measure entails dredging sediment from

nearby sections of the Atchafalaya and Mississippi Rivers and mechanically or hydraulically

moving it to the study area. The team coordinated with MVN Operations to determine the

amount of material available from federal navigation projects within and adjacent to the study

area. The quantities were insufficient to produce significant benefits at this time. This measure

is being studied further by the Beneficial Use of Dredged Material (BUDMAT) Program

authorized by WRDA 2007. The BUDMAT program encompasses the Louisiana coastal area

from Mississippi to Texas. Therefore, this measure could be implemented in the study area

under the BUDMAT program.

Sediment Delivery through Pipeline Infrastructure – This measure involves moving sediment

through existing abandoned pipelines or by other transportation methods from distant sediment

laden rivers to the study area. Salt water intrusion and lack of sediment degrade Terrebonne

marshes. In most cases, freshwater must be increased before marsh creation can be successful.

Therefore, the focus of the project was on freshwater delivery. There is currently a no costeffective method to move sediment long distances. Although unused pipeline infrastructure may

currently exist, pumping sediment through these pipes scours the pipe and quickly creates holes.

Additionally, there are significant technical, legal, and environmental issues to be overcome.

Because of the need for freshwater, the cost of sediment delivery and the timeframe required to

address these issues, this measure was not incorporated in this project. It may be incorporated as

a medium or long term LCA goal.

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Eradication Program for Nutria – This measure involves removing nutria from the study area to

reduce their negative effects on the Terrebonne marshes. The Louisiana Department of Wildlife

and Fisheries runs the Coastwide Nutria Control Program that is funded through the Coastal

Wetlands Planning, Protection, and Restoration Act (CWPPRA). The control program typically

removes 100,000 to 160,000 nutria from coastal marshes in St. Mary, Terrebonne, and Lafourche

Parishes annually and is effectively reducing nutria damage in the study area. Therefore, this

measure was eliminated from further consideration.

Control of Water Hyacinth – This measure involves removing water hyacinth to improve water

flow and reduce competition. The PDT conferred with local and regional water hyacinth experts.

These experts did not believe that water hyacinth was a significant issue in the area. Therefore,

this measure was not incorporated into any alternatives.

Groundwater Introduction – This measure was removed as an option from all study subunits. It

was removed primarily because the PDT determined that coastal groundwater may have a

moderate to high salinity level. Salinity is one of the major contributors to the degradation of

study area marshes. Additionally, groundwater would not contain the sediment and nutrient load

of a freshwater riverine source. Future operations and maintenance costs for the pumping

systems were a deterrent because of the potential for future funding constraints to influence

operation.

Creation of “No Wake” Zones – This measure involves restricting boat speeds to reduce the

effects of wave wash on marshes. Other restoration projects in the area have addressed the

problem of wave wash utilizing shoreline protection. The PDT determined that the areas

affected by shoreline erosion in the study area are currently being addressed with shoreline

protection by implementation under a separate authority (CIAP and CWPPRA), and therefore

this measure was screened out for consideration for the ARTM study.

3.3 Preliminary Alternative Plans

Alternative plans are singular or combinations of specific measures that collectively meet study

goals and objectives within the defined study constraints. Alternative plans and their component

measures will be assessed relative to the objective of National Ecosystem Restoration (NER).

3.3.1 Development of Alternative Plans

To focus the team’s efforts and guide alternative development, the PDT developed a list of

strategies. These strategies were developed to produce a full range of alternative plans as

required by the National Environmental Policy Act of 1969 (NEPA) and USACE regulations.

The strategies were designed to be significantly different from one another and to represent the

entire range of solutions from no action to full restoration in consideration of study goals,

objectives, and constraints. From these strategies, alternatives that contained suites of general

measures were developed. Specific measures were generated from the general measures. The

strategies are as follows:

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1. ARTM S1: No Action. Alternatives developed under this strategy will include no

measures from this study.

2. ARTM S2: Utilize Existing Flow along with Management Measures to Maximize

Restoration Efforts. Alternatives developed under this strategy will focus on modifying

the interior portions of the study area. They will not actively introduce additional

sediment and nutrient laden freshwater from other sources, but rather will attempt to

redistribute the existing inputs to more efficiently utilize fresh water.

3. ARTM S3: Utilize Increased Flow from the Atchafalaya River and Management

Measures to Maximize Restoration Efforts. Alternatives developed under this strategy

will focus on increasing supply from the Atchafalaya River to introduce additional

sediment and nutrient laden freshwater along with modifying existing interior flows.

4. ARTM S4: Utilize Increased Flow from Locations East of the Study Area and

Management Measures to Maximize Restoration Efforts. Alternatives developed under

this strategy will focus on attempting to draw water from outside the study area to the

east and modifying existing interior flows.

5. ARTM S5: Utilize Increased Flow from the Atchafalaya River and Locations East of the

Study Area and Management Measures to Maximize Restoration Efforts. Alternatives

developed under this strategy will combine strategies 2 – 4, thus focusing on maximizing

flow inputs from both the Atchafalaya River and locations east of the Study Area along

with modifying existing interior flows.

The PDT developed alternatives by determining suites of general measures that would

achieve the five strategies (Table 3.3). The PDT developed seven groups of general

measures that became the seven alternatives. Several of the general measures that were

carried forward from Section 3.2.2 were determined to be not applicable or unfeasible

and were not incorporated into the seven alternatives (Table 3.3). These measures and

the reasons they were not incorporated are discussed below Table 3.3. A full description

of the eight alternatives can be found in Section 3.3.2.

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Table 3.3 Strategy Measures

The general measures that make up the seven alternative plans which fall under the five

strategies. These general measures were then used to develop specific measures.

Strategies

S1. No

Action

S2. Utilize

Existing

Flow

S3. Increase

Atchafalaya

& Utilize

Existing

S4. Increase

East & Utilize

Existing

S5. Increase

East,

Atchafalaya &

Utilize Existing

General Measure Alt. 1 Alt. 2 Alt. 7 Alt. 3 Alt. 6 Alt. 4 Alt. 5

Freshwater Distribution Channels - X - X XX X

Gated Diversion Structures - X - X X X X

Culverts - X - X XX X

Outfall and Distribution

Management - X - X - X X

Open Constrictions to Water

Transport - X - X XX X

Management of H.N.C. Lock - X X X X X X

Canal Dredging and Placement - X - X XX X

Sediment Delivery from Distant Sources - - - - -- -

Construct Ridges to Create Marsh - X - X - X X

Bank and Shoreline Protection - - - X X- X

Traffic Management - Scheduling - X X X XX X

Target Area Planting - X - X X X X

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From the suite of general measures, 94 specific measures were developed to form seven

study alternatives. These alternatives and their specific measures were then evaluated by

the interagency PDT. Many of the specific measures were developed as part of Coastal

Wetlands Planning, Protection, and Restoration Act (CWPPRA) projects (Table 3.4;

Table 3.5). As part of the CWPPRA planning process, the problems and needs of the

area were considered. Thus many of the measures included in the study had already been

evaluated for their suitability and benefits. Thirty-three of these measures were

eliminated (Table 3.4).

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Table 3.4 Eliminated MeasuresSpecific measures that were not incorporated into the final alternative plans.

ID1 Measure Name Description Reason for Elimination

er consideration Eliminated from furth

CD5 Central Dredge Channel #5 Dredge canal to increase water moving past GIWW2 constriction Unfeasible to dredge canal deep enough to increase flow; CD4 accomplishes the same purpose.CM1 Central Marsh Berm #1 Slow water movement out of HNC CT1, included in the alternatives was less costly and accomplished the same purposeCMC1- 4 Central Marsh Creation #1 - #4 Create marsh from Bayou Pelton dredging Because of the uncertainty of the quantity of dredge material and availability of placement locations in the future the team felt that these measures could be beneficial side effects of dredging measures rather than separate measures.CT4-5 Central Terracing #4 - #5 Create marsh CT1 and CT6 - 8, retained in the alternatives duplicated the purpose of these measures and eliminated the need for CT4-5.CX1 Central Removal #1 Remove Hwy 3040 E. Tunnel Blvd under GIWW2, top of tunnel acts as low water dam As built drawings for the tunnel could not be found thus tunnel size and height were unknown and PDT could not determine if removal would improve GIWW flow. Additionally community leaders indicated tunnel removal was unacceptable.ED1 East Dredge Channel #1 Dredge new canal The area proposed for the new canal contains high quality wetlands and ES2 was more cost effective.ED4 East Dredge Channel #4 Dredge portion of Bayou L’eau Blue to move water from GIWW3 to Grand Bayou Basin Replaced by ED5.EM2 East Marsh #2 Create marsh along the shore of Catfish Lake

The purpose of these measures is being replicated by measure EM3 which is part of Alternatives 2 – 5. EM3 creates morehabitat at a lower cost. E01 East Shoreline Protection #1 Protect the shore of Catfish Lake

EP1 - 6 East Plug #1 - #6 Plug canals around Catfish LakeER1 East Gated Structure #1 Flood gates w/variable crest outfall to retain freshwater in Bayou Pointe au Chien; prevent saltwater intrusion From previous studies, the PDT determined the amount of water flowing through Bayou Pointe au Chien required a structure larger than space would allow. This measure may already be proposed as part of a different project.ES1 East Structure #1 Provide water control in new canal This measure was proposed to control water on the new canal created by ED1. ED1 was eliminated and thus this measure was not necessary.EW2 – 3 East Weir #2 & #3 Slow water movement from Catfish Lake The purpose of these measures is being replicated by measure EM3 which is part of Alternatives 2 – 5. EM3 creates additional marsh habitat.WC1 West Culvert #1 Flap-gated culverts to move lower salinity water from Lake Decade to S. marshes

No benefits could be determined for these features. There was not sufficient detail in the hydraulic model in the vicinity ofthese measures to determine if they would have beneficial effects on the area’s marshes. WC2 - 3 West Culvert #2 & #3 Sheet pile structure with flap-gates to move lower salinity water from Lake Decade to S. marshes

WD1 - 4 West Dredge Channel #1 & #4 Dredge Minors Canal and other canals to improve water movement to Lake DecadeWM1 West Marsh Creation #1 Create marsh This measure would redirect flow negatively impacting Penchant marshesWO1 West Shoreline Protection #1 Riprap bank of Bayou Chene opposite Bayou Penchant to protect Avoca Island marshes After this feature was included in this study, the Coastal Impact Assistance Program and the Coastal Wetlands Planning, Protection, and Restoration Act program received funding to construct it. Thus, it was removed.WS1 West Diversion Structure #1 Gated box culverts to increase GIWW2 flow by moving water through Lake Palourde

WS1, 2, 3, and 4 were measures to achieve the same goal. Further investigation indicated that WS4, which was retained,provided the most water while minimizing negative impacts. WS2 - 3 West Diversion Structure #2 & - #3 Gated box culverts to increase flow from Atchafalaya River to GIWW3

1. Measure ID – Measures are identified by a unique sequence such as WC1. The first letter describes the subunit location: W = Bayou Penchant, C = Lake Boudreaux, and E = Grand Bayou. The second and third lettersdescribe the type of measure: C = culvert, D = dredge, M & MC = marsh creation, X = removal, S = structure, L = lock, G = gap, P = plug, LV = levee, T = terracing, O = shoreline protection and W = weir. The number

provides a unique ID for that particular type of measure in that subunit.2. GIWW – Gulf Intracoastal Waterway

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Table 3.5 Alternative Measures.The following measures were included in one or more of the final alternative plans. For site plans and typical sections refer to Engineering Appendix L Annex 4.

Alt ID1 Measure Name Description No. of Barrels Size/ Width2 Invert/ Channel Bottom2 Lgth2 Purpose

All CL1 Central Lock Complex #1 Multi-purpose operation of proposed HNC4 Lock Complex N/A N/A -7 N/A Optimize operation of HNC lock for distribution of fresh water and prevention of saltwater intrusion2, 3,6, 8 EC5 East Culvert #5 Bridge construction with Obermeyer gates installed between the piers N/A 80 x 20 -14 552 Convey fresh water from GIWW5 to Grand Bayou under Hwy 24, same location as ES2

Alternative 2 - 5, 8

EC23 East Culvert #2 Box culvert; from TE-10 5 5x5 -4.5 26 Convey flow through existing levee from Grand Bayou to WEC33 East Culvert #3 Flap gated box culverts w/variable crest outfall; from TE-10 10 5x5 -5 75 Convey fresh water to the W through an existing levee and prevent saltwater movement from Grand Bayou to NWED63 East Dredge Channel #6 Dredge a portion of Grand Bayou; from Central and East Terrebonne FW Delivery Project N/A 290 -14 16818 Allow water movement to E Grand Bayou marshesEG13 East Spoil Gap #1 Gap in canal spoil bank; from TE-10 N/A 1.7 acres -0.5 750 Allow movement of fresh water from unnamed canal to marshes to the S/SWEG23 East Spoil Gap #2 Gap in canal spoil bank; from TE-10 N/A 0.5 acres -0.5 400 Allow movement of fresh water from unnamed canal to marshes to the EEP7 East Plug #7 Boat bay on Cutoff Canal at junction with Point au Chien N/A 20 -5 360 To retain fresh water to N; prevent saltwater from SEX13 East Removal #1 Rock weir removal; from TE-10 N/A 50 W -5 100 Increase water movement through canal - distribute fresh water from Grand BayouEX23 East Removal #2 Soil plug removal; from TE-10 N/A 50 W -5 130 Increase water movement through canal - distribute fresh water from Grand Bayou/St. Louis CanalCC3 Central Culvert #3 Gated control structure 6 10x10 -10 175 Increase fresh water delivery from HNC4 through Bayou Provost to Bayou Grand Caillou/Lake BoudreauxCC53 Central Culvert #5 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux systemCC63 Central Culvert #6 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux systemCC73 Central Culvert #7 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux systemCC83 Central Culvert #8 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux systemCC93 Central Culvert #9 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux systemCC103 Central Culvert #10 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux systemCC113 Central Culvert #11 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux systemCC123 Central Culvert #12 Aluminum flap-gated culvert; from TE-32a 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux systemCC133 Central Culvert #13 Box culverts with sluice gates under Hwy 57; from TE-32a 6 10x10 -10 175 Increase fresh water movement from HNC4/Bayou Grand Caillou to N Lake BoudreauxCC143 Central Culvert #14 Flap-gates each with a stop log bay; from TE-32a 3 4x4 -5 45 Convey fresh water from new channel to N marshesCC153 Central Culvert #15 Timber weir placed at 90 to flow with boat openings; from TE-32a N/A 68 W -2/-3.5 N/A Prevent short circuiting of fresh water through the N/S Gulf S Pipeline canalCD1 Central Dredge Channel #1 Dredge Bayou Provost N/A 70 W -10 5,691 Increase fresh water delivery from HNC4 through CC3 to Bayou Grand Caillou/Lake BoudreauxCD2 Central Dredge Channel #2 Dredge part of Bayou Butler N/A 45 W -10 1000 Increase fresh water movement from HNC4 through CS1 to Bayou Grand Caillou/Lake BoudreauxCD63 Central Dredge Channel #6 Dredge new water conveyance channel; from TE-32a N/A 45 W -10 7014 Convey fresh water from Bayou Pelton enlargement through CC14 to N Lake Boudreaux marshesCD73 Central Dredge Channel #7 Dredge Bayou Pelton to enlarge it; from TE-32a N/A 70 W -10 6416 Increase fresh water movement from HNC4 through CC13 to Bayou Grand Caillou/N Lake BoudreauxCP1 Central Plug #1 Soil plug in Robinson Canal N/A 175 W -10 25 Retain fresh water in Lake Boudreaux basin; prevent saltwater intrusion from Bayou Petit CaillouCP23 Central Plug #2 Soil plug in canal near Bayou Butler; from TE-32a N/A 60 W -10 25 Prevent short circuiting of fresh water through the N/S Gulf S Pipeline canalCS1 Central Diversion Structure #1 Bayou Butler sluice gated box culverts under Hwy 57 6 10x10 -10 100 Increase fresh water movement from HNC4 to Bayou Grand Caillou/Lake Boudreaux

2-5

EC6 East Culvert #6 Flap gated box culverts 8 8x8 -7 50 Allow water movement down St. Louis Canal under Hwy 24EC7 East Culvert #7 Flap gated box culverts 8 8x8 -7 40 Allow water movement down St. Louis Canal under roadED2 East Dredge Channel #2 Canal dredging N/A 50 -8 56270 Allow water movement from GIWW5 through EC6 & 7 to Grand Bayou basinED73 East Dredge Channel #7 Canal dredging; from Central and East Terrebonne FW Delivery Project N/A 150 -14 13081 Allow water movement further down Grand BayouEM1 East Marsh Berm #1 A linear soil berm placed perpendicular to flow N/A 30 W N/A 13000 To slow fresh water movement to the gulf; prevent saltwater intrusion from S

Alterna

tives 2 - 5 EM3 East Marsh Berm #3 A linear soil berm placed perpendicular to flow N/A 30 W N/A 37000 To slow fresh water movement to the gulf; prevent saltwater intrusion from S CC4 Central Culvert #4 Gated control structure 6 10x10 -10 175 Increase fresh water movement from HNC4 to Bayou Grand Caillou/Lake Boudreaux CD3 Central Dredge Channel #3 Dredge Falgout Canal N/A 70 W -10 4426 Increase fresh water movement from HNC4 through CC4 to Bayou Grand Caillou/Lake Boudreaux

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Alt ID1 Measure Name Description No. of Barrels Size/ Width2 Invert/ Channel Bottom2 Lgth2 Purpose

CLV13 Central Levee #1 New forced drainage levee; from TE-32a N/A

3.3.2 +

8

H

3.3.3 N

/

A

3.3.4 5

1

73

3.3.5 Prevent potential flooding from proposed increase in flows to N Lake Boudreaux

CLV23 Central Levee #2 New forced drainage levee; from TE-32a N/A +8 H N/A 1760 Prevent potential flooding from proposed increase in flows to N Lake BoudreauxCM2 Central Marsh Berm #2 A linear soil berm placed perpendicular to flow N/A 30 W N/A 11255 Retain fresh water in Lake Boudreaux and marshes to N; prevent saltwater intrusion from SCM3 Central Marsh Berm #3 A linear soil berm placed perpendicular to flow N/A 30 W N/A 8975 Retain fresh water in Lake Boudreaux and marshes to N; prevent saltwater intrusion from SCM4 Central Marsh Berm #4 A linear soil berm placed perpendicular to flow N/A 30 W N/A 23458 Retain fresh water in marshes to N; prevent saltwater intrusion from SCT13 Central Terracing #1 A grid of 10’ wide berms perpendicular to surge; from South Terrebonne Terracing Project N/A 359 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT23 Central Terracing #2 A grid of 10’ wide berms perpendicular to surge; from South Terrebonne Terracing Project N/A 40 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT33 Central Terracing #3 A grid of 10’ wide berms perpendicular to surge; from South Terrebonne Terracing Project N/A 109 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT63 Central Terracing #6 A grid of 10’ wide berms perpendicular to surge; from South Terrebonne Terracing Project N/A 71 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT73 Central Terracing #7 A grid of 10’ wide berms perpendicular to surge; from South Terrebonne Terracing Project N/A 83 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT83 Central Terracing #8 A grid of 10’ wide berms perpendicular to surge; from South Terrebonne Terracing Project N/A 156 acres -5 N/A Retain fresh water and prevent saltwater intrusionWD2 West Dredge Channel #2 Dredge a part of Carencro Bayou and create new canal N/A 200 -7 35463 Increase delivery of fresh water from Bayou Penchant to SE Penchant Basin marshesWP1 West Plug #1 Soil plug N/A 20 W -10 115 Retain fresher water in Bayou du Large and Lake Mechant and prevent saltwater intrusionWW23 West Weir #2 Rock filled sheet pile weir with boat openings; from TE-66 N/A 940 W -12 100 Constrict Grand Pass by 90% to minimize water exchange between Bayou du Large and Caillou Lake

2 - 6, 8ED33 East Dredge Channel #3 Canal dredging; from Central and East Terrebonne FW Delivery Project N/A 470 -14 16483 Convey fresh water from GIWW5 to Grand Bayou basin ED5 East Dredge Channel #5 Dredge new canal N/A 470 -14 1000 Convey fresh water from GIWW5 through ES2 or EC5 to Grand BayouAlt. 2 - 6CD4 Central Dredge Channel #4 Dredge a new secondary channel along the GIWW at Hwy 24 bridges N/A 70 -20 1852 Increase water volume moving past GIWW5constriction CC1 Central Culvert #1 Box culvert in CD4 channel under Hwy 24 bridge 6 10x10 -20 115 Increase water volume moving past GIWW5constriction CC2 Central Culvert #2 Box culvert in the CD4 channel under Hwy 24 bridge 6 10x10 -20 115 Increase water volume moving past GIWW5constriction

WD3 West Dredge Channel #3 Dredge a portion of GIWW5 N/A 50 -36 16339 Eliminate constriction in GIWW5

Alt. 3, 5, 6 WO2 West Shoreline Protection #2 Riprap the banks of Bayou Chene and Avoca Island Cutoff around the mouth of Bayou Penchant N/A Varies N/A 48000 Protect Penchant basin marshes from increased project-related flows WS4 West Diversion Structure #4 Gated box culverts 6 15x15 -15 365 Increase flow from Atchafalaya River to GIWW5 by moving water from Bayou Shaffer to Avoca Island Cutoff/Bayou Chene4&5EP8 East Plug #8 Soil plug in Bayou L’eau Bleu adjacent to Hwy 24 bridge N/A 200 W -10 25 Prevent recirculation of water from measure ES2, pump station ES2 East Diversion Structure #2 Pump station under Hwy 24 4 552 W -14 188 Pump water from GIWW5 to Grand Bayou, same location as EC5

1. Measure ID – Measures are identified by a unique sequence such as WC1. The first letter describes the subunit location: W = Bayou Penchant, C = Lake Boudreaux, and E = Grand Bayou. The second and third lettersdescribe the type of measure: C = culvert, D = dredge, M & MC = marsh creation, X = removal, S = structure, L = lock, G = gap, P = plug, LV = levee, T = terracing, O = shoreline protection and W = weir. The numberprovides a unique ID for that particular type of measure in that subunit. In some cases, measures were redesigned but the ID was retained.2. All measurements are approximate. Unless otherwise noted, all measurements are in feet.3. Measures in bold were proposed as part of a Coastal Wetlands Planning, Protection, and Restoration Act project; the source project number or name is indicated in the description column.

4. HNC – Houma Navigation Canal5. GIWW – Gulf Intracoastal Waterway

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3.3.2 Description of Alternative Plans

The plan formulation process involved the grouping of management measures in

accordance with the overall strategies discussed earlier in this chapter. The management

measures, for the most part, were considered under past authorities and studies

(CWPPRA and CIAP), but were combined for the ATRM study to form holistic basin

wide Alternatives. The contribution to planning objectives of each alternative is

discussed in Chapter 5. The information on these alternatives includes: graphs and maps

showing each alternative’s effects on salinities and freshwater flows at various locations,

changes in vegetation types, increases in marsh, and reduction in open water. After

developing the seven alternatives (Table 3.3), the PDT realized that Alt. 2 - 5 contained a

large number of measures while Alt. 6 and 7 contained a few measures. The team felt

that an Alternative containing an intermediate number of measures was necessary. Thus,

Alternative 8 was developed as another alternative that achieves some of the benefits of

Alternative 2 with less cost. Alternatives 2 – 8 incorporate various combinations of the

remaining 61 measures (Figures 3.3 – 3.9). To distinguish the features in the northern

portion of the Lake Boudreaux basin for Alternatives 2 through 5 and 8, see Figure 3.10.

Site plans and typical sections for these measures can be found in Engineering Appendix

L Annex 4. Modification to the operation of the proposed HNC Lock complex is

included in all action alternatives in accordance with guidance received from the LCA

Program Management Team. This was done because the HNC Lock Operations are

hydrologically linked to all alternatives developed for ARTM in a synergistic and holistic

approach to the problems and opportunities of the study area, although benefits on are not

necessarily dependent on the implementation on the HNC Lock complex. A description

of this measure can be found under Section 3.3.9. The remaining 61 measures were

incorporated into various alternatives (Table 3.5).

3.3.2.1 No Action (Future without Project Conditions) – Strategy: No Action.

This alternative includes no measures from this study. The future condition will include

sea level rise, subsidence, and other projects that are under construction or are likely to be

constructed. This alternative includes operation of the HNC lock complex under the

Morganza to the Gulf operations plan. The assumption was made that the Morganza to

the Gulf Project would be completed by 2025. The operating plan for the Morganza to

the Gulf HNC flood gates calls for closure of the flood gates whenever necessary to

prevent saltwater intrusion up the HNC or during tropical storm/hurricane conditions.

Accordingly, for purposes of future without project hydraulic modeling, the assumption

was made that the HNC flood gates would be closed to prevent saltwater intrusion for

two months each year starting in 2025. During these closure periods, it was assumed that

the sluice gates within the HNC Lock structure would be open. Other water control

structures associated with the Morganza to the Gulf Project would only be utilized under

tropical storm/hurricane conditions, and, therefore, would not appreciably impact the

hydrology of the study area under normal operating conditions. Therefore, these

structures were not included in the hydraulic modeling for the LCA-ARTM study.

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3.3.2.2 Alternative 2 - Strategy: Utilize Existing Flow and Management Measures

(Figure 3.3).

This alternative redistributes existing freshwater to benefit Terrebonne marshes using a

variety of measures (Table 3.5 Alternative Measures). To achieve this, GIWW

constrictions would be eliminated. Additionally, the following measures to restrict

increase, and control water are proposed for each of the three subunits. In the West –

Bayou Penchant Area, dredging, a sediment plug, and a weir will be utilized. In the

Central – Lake Boudreaux Area, culverts, levees, dredging, marsh terraces and berms,

sediment plugs, modified operation of the future HNC (Houma Navigation Canal) lock

complex, , as described in Alternative 7, and a large sluice gated box culvert are

proposed. In the East – Grand Bayou Area, culverts, dredging, gaps in canal spoil banks,

marsh berms, sediment plugs, and removal of a weir and soil plug are proposed.

3.3.2.3 Alternative 3 - Strategy: Increase Atchafalaya River Flows and Utilize

Management Measures (Figure 3.4).

This alternative will increase Atchafalaya River inflows and redistribute existing and

increased flows of freshwater. Alternative 3 includes all the measures in Alternative 2

and two additional. The additional measures are in the West – Bayou Penchant Area. To

increase flows from the Atchafalaya River, water will be moved from Bayou Shaffer to

the Avoca Island Cutoff/Bayou Chene. This will be accomplished by creating an opening

through the Avoca Island levee and installing a large gated diversion structure (WS4) in

the opening. The remaining measure (WO2) would place stone along the shore of Bayou

Chene and Avoca Island Cutoff to protect from increased flows.

3.3.2.4 Alternative 4 - Strategy: Increase Flow from East of the Study Area and Utilize

Management Measures (Figure 3.5).

This alternative will increase freshwater flows from east of the study area and redistribute

existing and increased flows of freshwater. Alternative 4 includes all but one of the

measures in Alternative 2, and has two additional measures in the East – Grand Bayou

Area. In Alternative 2, a new Hwy. 24 bridge with Obermeyer gates between the piers

(EC5) is proposed to connect the GIWW to Grand Bayou. In Alternative 4, this measure

is replaced by a pump station (ES2). The pump station would increase freshwater

delivery to the Grand Bayou watershed but not the other subunits. The second new

measure is a soil plug (EP8) in Bayou L’eau Bleu. Bayou L’eau Bleu connects the canal

receiving the pump station outflow to the GIWW. The pump station is pumping water

from the GIWW, thus the soil plug is necessary to prevent recirculation of water.

3.3.2.5 Alternative 5 - Strategy: Increase Flow from the East and from the Atchafalaya

River and Utilize Management Measures (Figure 3.6).

This alternative will increase flows from the east and west and redistribute existing and

increased flows of freshwater. This alternative is a combination of Alternatives 3 and 4.

The only measure in Alternative 3 not within this alternative is the Hwy. 24 bridge with

Obermeyer gates (EC5), which is replaced by a pump station (ES2), as in Alternative 4.

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3.3.2.6 Alternative 6 - Strategy: Increase Atchafalaya River Flow and Utilize

Management Measures (Figure 3.7).

This alternative will increase Atchafalaya River inflows and improve the passage of

freshwater through the GIWW while slowing water passage to the gulf through the HNC.

Alternative 6 differs from Alternative 3 because Alternative 6 only includes water

management measures along the GIWW. The measures to increase Atchafalaya River

inflows are the same as Alternative 3. A large gated diversion structure (WS4) would be

placed in the new opening created in the Avoca Island levee. Shoreline protection would

be placed (WO2) in Bayou Chene and Avoca Island Cutoff. To improve freshwater

flows through the GIWW to Grand Bayou, the following measures from Alternative 2 are

proposed. In East – Grand Bayou Area, dredging is proposed to connect Grand Bayou to

the GIWW (ED5) and enlarge Grand Bayou (ED3). Where ED5 goes through Hwy. 24, a

new bridge with Obermeyer gates between the piers (EC5) is proposed. In Central –

Lake Boudreaux Area, the GIWW is constricted as it passed under Hwy. 24. The Hwy.

24 bridge columns does not allow for channel enlargement. Therefore, dredging a new

secondary channel with two culverts, one under each Hwy. 24 bridge, is proposed.

Modifying the operation of the HNC Lock Complex, as described in Alternative 7, is also

included in this alternative.

3.3.2.7 Alternative 7 - Strategy: Utilize Existing Flow and Management Measures

(Figure 3.8).

This alternative will slow the movement of freshwater to the Gulf of Mexico and thus put

additional freshwater onto northern Terrebonne marshes. The one measure in this

alternative is the modified operation of the proposed HNC Lock Complex (CL1). The

HNC Lock Complex is part of the proposed U.S. Army Corps of Engineers Morganza to

the Gulf project for coastal storm damage reduction. The assumption was made that the

Morganza to the Gulf Project would be completed by 2025. The operating plan for the

Morganza to the Gulf HNC lock complex calls for closure of the flood gates whenever

necessary to prevent saltwater intrusion up the HNC or during tropical storm/hurricane

conditions. Accordingly, for purposes of future without project hydraulic modeling, the

assumption was made that the HNC flood gates would be closed to prevent saltwater

intrusion for two months each year starting in 2025. Alternative 7 proposes to keep the

flood gates closed year round to hold water back, thus moving freshwater onto northern

marshes. When the flood gates are closed boat traffic would travel through the lock

chambers. As part of this alternative, an industry traffic management plan would be

developed for vessels exceeding the lock size that will require the flood gates to be

opened. This alternative proposes to keep the sluice gates located in the lock structure

walls open, with the exception of during tropical events.

3.3.2.8 Alternative 8 - Strategy: Utilize Existing Flow and Management Measures to

Focus Fresh Water Flows on the Most Critical Areas of the East and Central Study

Sub Units (Figure 3.9).

This alternative redistributes existing freshwater to benefit the most critical areas of the

east and central study subunits using a variety of measures (Table 3.5 Alternative

Measures). This alternative represents an increment between Alternative 7 and

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Alternative 2 and contains many of the features of Alternative 2. In the Central – Lake

Boudreaux Area, culverts, levees, dredging, sediment plugs, modified operation of the

future HNC (Houma Navigation Canal) lock complex, as described in Alternative 7, and

a large sluice gated box culvert are proposed. In the East – Grand Bayou Area, culverts,

dredging, gaps in canal spoil banks, sediment plugs, and removal of a weir and soil plug

are proposed.

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Figure 3.3 Alternative 2. Alternative 2 incorporates 4 of the 8 total measures in the West Bayou Penchant Area, all 36 in Center – Lake Boudreaux and 17 of the 19 in East – Grand Bayou Subunit

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Figure 3.4 Alternative 3. Alternative 3 incorporates 6 measures in the West – Bayou Penchant Area, all 36 in Center - Lake Boudreaux and 17 in East - Grand Bayou. It differs from Alternative 2 by the additional measures in the west.

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Figure 3.5 Alternative 4. Alternative 4 incorporates 4 measures in the West – Bayou Penchant Area, all 36 in Center - Lake Boudreaux and 18 in East - Grand Bayou. It differs from Alternative 2 by having two additional and one different measure in

the east.

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Figure 3.6 Alternative 5. Alternative 5 incorporates 6 measures in the West – Bayou Penchant Area, 36 in Center - Lake Boudreaux and 18 in East - Grand Bayou. This alternative is a combination of Alternatives 3 and 4.

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Figure 3.7 Alternative 6. Alternative 6 incorporates 4 measures in the West – Bayou Penchant Area, 4 in Center - Lake Boudreaux and 3 in East - Grand Bayou

The measures in this alternative increase flows from the Atchafalaya River to the west and improve flows through the Gulf Intracoastal Waterway to the center and eastern subunits.

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Figure 3.8 Alternative 7. Alternative 7 incorporates only 1 measure which is in the Center - Lake Boudreaux Subunit. This measure proposes to change the operation of the proposed Houma Navigation Canal Lock Complex.

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Figure 3.9 Alternative 8. Alternative 8 incorporates 22 measures in the Center - Lake Boudreaux Area and 11 in East - Grand Bayou. This alternative is a subset of Alternative 2.

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Figure 3.10 Features located in the north Lake Boudreaux area for Alternatives 2 through 5 and 8.

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3.3.3 Screening / Evaluation of Alternative Plans

During the interagency PDT meetings, the team, including sister federal agencies and

local sponsors, reviewed and evaluated the seven proposed alternatives against the project

goals and objectives. They also assessed the alternative plans and their component

measures relative to the objective of National Ecosystem Restoration (NER).

3.3.4 Alternative Plans not Carried Forward for Further Analysis

As discussed above, some specific measures were eliminated from the seven action

alternatives (Table 3.4). However, all seven initial alternatives were carried forward for

further analysis.

3.4 Final Array of Alternatives (Alternatives Studied in Detail)

A complete description of the final array of alternatives is included in section 3.3.2.

3.5 Comparison of Alternative Plans

3.5.1 Incremental Cost/Cost Effectiveness Analysis Process.

Cost effectiveness analysis was used to determine what features should be built based on

habitat benefits (outputs) that meet the goals and objectives of the study and at the same

time are the most cost effective. The Corps has incorporated cost effectiveness analysis

into its planning process for all ecosystem restoration planning efforts. A cost

effectiveness analysis is conducted to ensure that least cost alternatives are identified for

various levels of output. After the cost effectiveness of the alternatives has been

established, incremental cost analysis is conducted to reveal and evaluate changes in cost

for increasing levels of environmental output.

Cost effectiveness and incremental analysis is a three step procedure: (1) calculate the

environmental outputs of each alternative; (2) determine a cost estimate for each

alternative; (3) combine the alternatives to evaluate the best overall alternative based on

habitat benefits and cost. While cost and environmental outputs are necessary factors,

other factors such as the ability to construct, schedule, likelihood to achieve projected

results, immeasurable environmental benefits, ancillary benefits etc., are very important

in deciding on the preferred alternative.

Environmental outputs were calculated as Average Annual Habitat Units (AAHUs). The

annualized costs were calculated by applying a 4-3/8 percent annual interest rate to the

construction costs over the 50-year period of analysis. What is described below is the

second step of the process introduced in Section 3.3.4 above.

3.5.2 Wetland Value Assessment (WVA)

The Wetland Value Assessment (WVA) methodology is a quantitative habitat-based

assessment methodology developed for use in determining wetland benefits of project

proposals submitted for funding under the Coastal Wetlands Planning, Protection, and

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Restoration Act (CWPPRA). The WVA quantifies changes in fish and wildlife habitat

quality and quantity that are expected to result from a proposed wetland restoration

project. The results of the WVA, measured in Average Annual Habitat Units (AAHUs),

can be combined with cost data to provide a measure of the effectiveness of a proposed

project in terms of annualized cost per AAHU gained. In addition, the WVA

methodology provides an estimate of the number of acres benefited or enhanced by the

project and the net acres of habitat protected/restored.

The WVA was developed by the Environmental Work Group (EnvWG) assembled under

the Planning and Evaluation Subcommittee of the CWPPRA Technical Committee; the

EnvWG includes members from each agency represented on the CWPPRA Task Force

and members of the Academic Assistance Subcommittee. The WVA was designed to be

applied, to the greatest extent possible, using only existing or readily obtainable data.

The WVA has been developed strictly for use in determining the wetland benefits of

proposed CWPPRA projects; it is not intended to provide a detailed, comprehensive

methodology for establishing baseline conditions within a study area. Some aspects of

the WVA have been defined by policy and/or functional considerations of the CWPPRA;

therefore, user-specific modifications may be necessary if the WVA is used for other

purposes.

The WVA is a modification of the Habitat Evaluation Procedures (HEP) developed by

the U.S. Fish and Wildlife Service (U.S. Fish and Wildlife Service 1980). HEP is widely

used by the Fish and Wildlife Service and other Federal and state agencies in evaluating

the impacts of development projects on fish and wildlife resources. A notable difference

exists between the two methodologies, however, in that HEP generally uses a speciesoriented approach, whereas the WVA utilizes a community approach.

The WVA has been developed for application to several habitat types along the Louisiana

coast and community models have been developed for fresh marsh, intermediate marsh,

brackish marsh, saline marsh, fresh swamp, barrier islands, and barrier headlands. A

WVA Procedural Manual has also been prepared by the EnvWG to provide guidance to

project planners in the use of the various community models. Two other habitat

assessment models for bottomland hardwoods and coastal chenier/ridge habitat were

developed outside of the CWPPRA arena and are periodically used by the EnvWG.

WVA Concept

The WVA operates under the assumption that optimal conditions for fish and wildlife

habitat within a given coastal wetland habitat type can be characterized, and that existing

or predicted conditions can be compared to that optimum to provide an index of habitat

quality. Habitat quality is estimated or expressed through the use of community models

developed specifically for each habitat type. Each model consists of 1) a list of variables

that are considered important in characterizing fish and wildlife habitat, 2) a Suitability

Index graph for each variable, which defines the assumed relationship between habitat

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quality (Suitability Index) and different variable values, and 3) a mathematical formula

that combines the Suitability Index for each variable into a single value for habitat

quality; that single value is referred to as the Habitat Suitability Index, or HSI. The

output of each model (the HSI) is assumed to have a linear relationship with the

suitability of a coastal wetland system in providing fish and wildlife habitat.

The WVA models have been developed for determining the suitability of Louisiana

coastal wetlands in providing resting, foraging, breeding, and nursery habitat to a diverse

assemblage of fish and wildlife species. The models have been designed to function at a

community level and therefore attempt to define an optimum combination of habitat

conditions for common fish and wildlife species utilizing a given habitat type. Earlier

attempts to capture other wetland functions and values such as storm-surge protection,

flood water storage, water quality functions, and nutrient import/export were abandoned

due to the difficulty in defining unified model relationships and meaningful model

outputs for such a variety of wetland benefits. However, the ability of a Louisiana

coastal wetland to provide those functions and values may be generally assumed to be

positively correlated with fish and wildlife habitat quality as predicted through the WVA.

Community Model Variable Selection

Habitat variables considered appropriate for describing habitat quality in each wetland

type were selected according to the following criteria:

o The condition described by the variable had to be important in characterizing fish

and wildlife habitat quality in the wetland type under consideration;

o Values had to be easily estimated and predicted based on existing or readily

obtainable data (e.g., aerial photography, habitat classification data, water quality

monitoring stations, interviews with knowledgeable individuals, etc.); and

o The variable had to be sensitive to the types of changes expected to be brought

about by typical wetland restoration projects proposed under CWPPRA.

Suitability Index Graphs

A suitability index graph is a graphical representation of how fish and wildlife habitat

quality or "suitability" of a given habitat type is predicted to change as values of the

given variable change, and allows the model user to numerically describe, through a

Suitability Index, the habitat quality of a wetland area for any variable value. Each

Suitability Index ranges from 0.1 to 1.0, with 1.0 representing the optimal condition for

the variable in question. Suitability Index (SI) graphs were constructed for each variable.

Habitat Suitability Index Formula

The final step in model development was to construct a mathematical formula that

combines all Suitability Indices into a single Habitat Suitability Index value. Because the

Suitability Indices range from 0.1 to 1.0, the HSI also ranges from 0.1 to 1.0, and is a

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numerical representation of the overall or "composite" habitat quality of the particular

wetland area being evaluated. The HSI formula defines the aggregation of Suitability

Indices in a manner unique to each wetland type depending on how the formula is

constructed.

Within an HSI formula, any Suitability Index can be weighted by various means to

increase the power or "importance" of that variable relative to the other variables in

determining the HSI. Additionally, two or more variables can be grouped together into

subgroups to further isolate variables for weighting.

Benefit Assessment

The net benefits of a proposed project are estimated by predicting future habitat

conditions under two scenarios: future without-project and future with-project.

Specifically, predictions are made as to how the model variables will change through

time under the two scenarios. Through that process, HSIs are established for baseline

(pre-project) conditions and for future without- and future with-project scenarios for

selected "target years" throughout the expected life of the project. Those HSIs are then

multiplied by the study area acreage at each target year to arrive at Habitat Units (HUs).

Habitat Units represent a numerical combination of quality (HSI) and quantity (acres)

existing at any given point in time. The HUs resulting from the future without- and

future with-project scenarios are annualized, averaged over the period of analysis, to

determine Average Annual Habitat Units (AAHUs). The "benefit" of a project can be

quantified by comparing AAHUs between the future without- and future with-project

scenarios. The difference in AAHUs between the two scenarios represents the net benefit

attributable to the project in terms of habitat quantity and quality.

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Summary

Based on the WVA process AAHUs were calculated for each of the alternatives and are

summarized below. It should be noted that the benefits presented below were calculated

without fisheries access impacts (WVA variable 6) associated with the Grand Pass weir

(WW2), the Robinson Canal plug (CP1), the Cutoff Canal plug (EP7), and the operation

of the HNC Lock Complex (CL1). Inclusion of fisheries access impacts in the

calculation of AAHUs may have resulted in negative AAHUs for all alternatives, despite

net gains in wetland acreages. These measures are designed to correct significant

hydrologic alterations on man-made canals which are thought to be significant causes of

wetland degradation and loss and which resulted in artificially increased fisheries access.

In addition, other natural and man-made waterways exist for fisheries access. Therefore,

the decision was made to eliminate this potential impact when calculating benefits

associated with each alternative. Potential modifications to this methodology are being

investigated by USFWS in consultation with NMFS, LDWF, and other interested natural

resource agencies.

Benefits Summary

Alternative Projected Land Area

in 2065 (acres)

(Projected Land Area

in 2015 = 560,321

acres)

Projected Land

Loss over Period

of Analysis

(2015 to 2065)

Land Loss

Prevented

(acres)

Total

AAHUs

Net

AAHUs

No Action 458,751 101,570 --- 96,937 ---

2 468,406 91,915 9,655 100,157 3,220

3 469,059 91,262 10,308 100,262 3,325

4 470,955 89,366 12,204 101,195 4,258

5 472,685 87,636 13,934 101,656 4,719

6 458,758 101,563 7 97,713 776

7 456,100 104,221 -2,651 97,180 243

8 459,740 100,581 989 98,151 1,214

3.5.3 Cost Estimates for Habitat Improvement Measures

Rough cost estimates were developed to conduct the cost effectiveness and incremental

cost analysis of the various alternative plans. Items included in the first cost construction

estimates are mobilization, dredging, placement, demobilization, contingency,

Engineering and Design during Construction (EDC), Supervision & Administration

(S&A), Real Estate and Operations and Maintenance. Table 3.6 summarizes the costs

associated with each alternative plan. Following selection of the RP, the design will be

refined and a feasibility level cost estimate prepared. Therefore, the cost of the

recommended plan may differ from the numbers used during the Cost Effectiveness/

Incremental Cost Analysis (CE/ICA) process. Further details can be found in the

Engineering and Cost Appendices.

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Table 3.6 LCA: Atchafalaya CE/ICA: Step 1

Alternative Costs

Alternative First Cost*

Annualized

First Cost**

Annualized

Monitoring

Cost**

Annualized

OMRR&R**

&***

Total

Annualized

Investment

Cost

Alt. 1 (No Action) N/A N/A N/A N/A N/A

Alt. 2 $203,047,200 $10,066,504 $396,686 $72,514 $10,535,704

Alt. 3 $232,041,000 $11,503,935 $396,686 $75,889 $11,976,509

Alt. 4 $253,038,800 $12,544,946 $396,686 $1,656,894 $14,598,526

Alt. 5 $294,899,600 $14,620,286 $396,686 $1,660,269 $16,677,241

Alt. 6 $134,199,000 $6,653,206 $396,686 $10,175 $7,060,066

Alt. 7 $42,000 $2,082 $258,513 $0 $260,595

Alt. 8 $86,777,600 $4,302,187 $396,686 $48,684 $4,747,557

*Includes Real Estate and

Cultural Resources

**Discount Rate: 4-3/8%

*** The operation costs for

the HNC Lock Complex

have not been developed

under Morganza to the Gulf

at this time

At this point in the analysis, Alternatives 4 and 5 were removed from consideration. At

the TSP meeting, it was determined Alternatives 4 and 5 were not sustainable from an

efficiency or acceptability standpoint. These alternatives required a large 4000 cfs

pumping station at the confluence of the GIWW and Grand Bayou. The large pump

station adversely impacted the isohalines in the Barataria basin and would have forced

salt water intrusion up into Bayou Lafourche (see Section 5.3 in Environmental

Consequences). The interagency team determined that these were unacceptable adverse

environmental impacts and precluded the alternatives from further consideration and

analysis. The effects of this pumping station do not conform to the USACE

Environmental Operating Principles concerning sustainability.

3.5.4 Results of the CE/ICA Analysis

The CE/ICA analysis shows remaining Alternative plans 2, 3, 7, and 8 to be cost

effective. Aside from the No Action Alternative, Alternative 7 exhibited the lowest

average annual cost per Unit of all Alternatives, $1,072 per AAHU. Alternative 8

exhibited the highest average annual cost per Unit of all Alternatives, $3,910 per AAHU.

However, as the Plans are linear in benefits and costs, a CE/ICA is conducted on all of

the cost effective Alternatives to determine the ‘best buy” plans. “Best buy” plans are the

most efficient alternatives/plans at producing the output variable AAHUs. In other

words, best buy plans provide the greatest increase in the value of the output parameter

variable for the least increase in the value of the cost parameter variable.

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Table 3.7 LCA: Atchafalaya CE/ICA: Step 2

LCA: Atchafalaya CE/ICA: STEP 2

WVA

Net AAHU

Annualized

Cost Per

Unit

Alternative (AAHU)

Total

Annualized

Investment

Cost*

Alternative 7 $260,595 243 $1,072

Alternative 8 $4,747,577 1,214 $3,910

Alternative 2 $10,535,704 3,220 $3,272

Alternative 3 $11,976,509 3,325 $3,601

*Includes Real Estate and

Cultural Resources

**Discount Rate 4-3/8%

Figure 3.11: CE/ICA of Final Alternatives

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Overall, the CE/ICA process resulted in Alternatives 7, 2 and 3 being evaluated as “best

buy” plans.

As shown in Table 3.8, Alternative 7 provides 243 AAHUs at an annualized incremental

cost of $260,595. Alternative 2 provides 2,977 additional AAHUs, at an annualized

incremental cost of $10,275,120. Alternative 3 provides 106 additional AAHUs at an

annualized incremental cost of $1,440,805. The first best buy plan is the most efficient

plan from an incremental cost per AAHU perspective. However, if a higher level of

output (AAHUs) is desired than that provided by the first best buy plan, the second best

buy plan becomes the most efficient plan for producing additional output, and so on. The

recommended Best Buy Plan is Alternative 2, generating 3,220 WVA AAHUs at a total

annualized investment cost of $10,535,704.

Table 3.8 LCA: Atchafalaya CE/ICA: Step 3

Incremental Cost/Cost Effectiveness Analysis

of Cost Effective Plans

Alternative

Total

Annualized

Investment

Cost

WVA

AAHUs

Incremental

Cost

Incremental

AAHUs

Incremental

Cost per

AAHUs

Alternative 7 $260,595 243 $260,595 243 $1,072

Alternative 2 $10,535,704 3,220 $10,275,109 2,977 $3,452

Alternative 3 $11,976,509 3,325 $1,440,805 106 $13,650

*Includes Real Estate

and Cultural Resources

**Discount Rate 4-3/8%

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Figure 3.12: CE/ICA Best Buy Plans

3.5.5 Other Factors

As part of the process to determine if additional increments of ecosystem investment are

worth the cost, other factors were considered.

3.5.5.1 Recreational Benefits

The primary purpose of the Atchafalaya River Study is to determine a cost effective

ecosystem restoration plan. However, there are potential ancillary benefits to recreation.

Recreation benefits are not being claimed to justify the project but are useful in

discerning among the final alternatives. For more information on calculation of

recreation benefits, see Appendix Q – Recreation Incidental Benefits.

Given that the area has 665,020 unit days per year and that each unit day is valued at

$9.72, the total annual monetary value of the recreational resource that would be affected

by the LCA-ARTM project is $6,464,657. Given that the likelihood of success with

fishing will increase and that environmental factors will improve over time if the

proposed project is implemented, the total annual monetary value of the recreational

resource will increase in the future compared to the annual monetary value of the

recreational resource should the proposed project not be implemented.

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To better understand the economic impact of the proposed project on recreation, the

analysis considered effects over a 50-year period. The analysis uses the Federal discount

rate for FY 2010 of 4.375 percent. The following table summarizes the potential net

present value of the proposed project for each alternative showing that the proposed

project will benefit recreational opportunities.

Table 3.9 Net Increase in Incidental Recreation Benefits

Without

Project

Alternative

2

Alternative

3

Alternative

4

Alternative

5

Alternative

6

Alternative

7

Alternative

8

Net Present

Value

$0 $2,077,000 $2,799,000 $1,588,000 $1,505,000 $252,000 $190,000 $2,057,000

Annualized $0 $102,505 $138,137 $78,371 $74,275 $12,437 $9,377 $101,518

3.5.5.2 Desired Future Condition

The desired future condition established early on in the study was to achieve no loss of

marsh acres at the end of the 50-year period of analysis. While it was desirable to

maximize the acres of marsh, it was uncertain if that was possible given the various

physical and operational constraints. Alternative 2 decreases loss of marsh over the 50-

year period of analysis by 9,655 acres.

3.5.5.3 Adaptive Management

Alternative 2 provides robust capability for adapting to future risk and uncertainty. The

robust nature of the engineering features included in Alternative 2, such as box culverts,

an Obermeyer Gate, and soil berms are such that they can be adjustable throughout the

project life. For instance an Obermeyer Gate’s aperture can be changed or closed off

entirely, soil berms can be raised, lowered or gapped, and box culverts can be restricted

or closed and in some cases another culvert can be added to a feature for more flow.

Alternative 2 provides for flexible management of operations to respond to sea level rise.

Just as sea level rise represents uncertainty at one end of the spectrum, it is also possible

that sea level rise will not be any more pronounced than historic levels. Also, the science

of operating water control structures and the HNC Lock complex will be refined

throughout the period of analysis. Finally, it is expected that as the project is actually

operated and benefits are achieved, it will be of value for the Federal, state and local

partnership to revisit the goals and objectives associated with the study area. If the

project is proving to be very successful at creating marsh it may no longer be necessary to

maintain the diversion capability at Grand Bayou.

3.5.5.4 Acceptability, Completeness, Effectiveness, and Efficiency

Alternative 2 meets the four evaluation criteria of the Economic and Environmental

Principles and Guidelines for Water and Related Land Resources Implementation

Studies. Special consideration is also given to these criteria within the larger context of

the LCA Report (2004). The four criteria are acceptability, completeness, effectiveness,

and efficiency.

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Acceptability. The plan is acceptable to Federal, state, tribal, local entities, and the public.

It is compatible with existing laws, regulations, and policies.

Completeness. The plan is complete. Realization of the plan does depend on

implementation of actions outside the plan: the Houma Navigation Canal Lock complex

is part of the Morganza to the Gulf of Mexico Hurricane Protection Project. The HNC

Lock is an authorized project with an expected competition date of 2019.

Effectiveness. The plan is effective. It addresses all but one of the project objectives. It

improves marsh habitat by restoring deltaic process related to freshwater and nutrients,

but does not address sediment input into the system. No alternatives considered would

have addressed the sediment objective.

Efficiency. The plan is efficient. It is a cost-effective solution to the stated problems and

objectives. No other plan produces the same level of output more cost effectively. The

plan is cost effective and provides the greatest increase in benefits for the least increase in

costs.

3.5.5.5 Recommended Plan

The interagency team recommends Alternative Plan 2 as the Recommended plan (RP).

This alternative best meets the study objectives. It would result in restoration of some

deltaic processes within the study area. In cooperation with the USFWS, NOAA, and the

State of Louisiana the Corps has planned and would design a project that serves the needs

of the nation. Per guidance received from Commander of Mississippi Valley Division,

Alternative 2 fits into the framework of Section 902 cost cap limit of WRDA 1986, and

as such, no further Congressional action for authorization would be required.

3.6 NER Plan

The NER plan reasonably maximizes ecosystem restoration benefits compared to costs,

considering the cost effectiveness and incremental cost of implementing other restoration

options. Alterative 2 will utilize flow management measures to achieve sustainable

environmental benefits in nationally significant aquatic ecosystem. Existing freshwater

will be more efficiently distributed and flows will be increased where possible.

3.6.1 Components of NER Plan

Refer to table 3.5 for code definition of Alternative Measures.

The NER Alternative (Alt 2) involves construction of 56 structures and other water

management features and the opportunistic operation of the Houma Navigation Lock

complex in an effort to holistically address the declining health of the Terrebonne

Marshes ecosystem. There are two water diversion structures that are at critical points in

the Terrebonne Marshes. The Central Diversion Structure (CS1), which involves

constructing six 10' x 10' gated box culverts on Bayou Butler under Highway 57, will

increase fresh water movement from the HNC to Bayou Grand Caillou/Lake Boudreaux.

The Eastern Culvert #5 (EC5) is composed of a bridge with five 83-ft. spans with two

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68.5-ft. spans accommodating Highway 24. Associated with this bridge are five 80-ft.

Obermeyer gated openings, for a total flow opening width of 400 feet. EC5 is intended to

convey fresh water from the GIWW to Grand Bayou under Highway 24.

Other project measures in the western portion of the project area include 51,802 feet of

dredging (WD2 and WD3), which increases delivery of fresh water from Bayou Penchant

to southeast Penchant Basin marshes and eliminates a constriction in the GIWW. A soil

plug (WP1) will be placed to retain fresher water in Bayou du Large and Lake Mechant

and prevent saltwater intrusion. A rock filled sheet pile weir with boat openings will

constrict Grand Pass by 90% to minimize water exchange between Lake Mechant and

Caillou Lake. WW2 is a boat bay structure located in Grand Pass on the south side of

Bayou DuLarge. A rock weir is centered on the channel with sheet pile cell walls on

either side. The boat bay opening is 100 feet wide with an invert elevation of -12 ft. The

entire structure has a width of 940 ft.

There are several project measures in the central project area in addition to the Central

Diversion Structure. A set of three measures (CC1, CC2, and CD4) will increase water

volume moving past the GIWW constriction at the twin span bridge in Houma. Several

project measures (CT1-8, CM2, CM3, CC3-15, CD1-2, 6, 7, CLV1, CLV2, and CP2) will

work in conjunction with the Central Diversion Structure to deliver and retain fresh water

and to prevent greater salt water intrusion into Lake Boudreaux. A 23,500 linear foot soil

berm (CM4) will be placed perpendicular to tidal flow to retain fresh water in marshes to

the north and prevent saltwater intrusion from the south in the marshes to the west of the

proposed HNC Lock. A soil plug (CP2) will be placed in a canal near Bayou Butler to

prevent short circuiting of fresh water through the N/S Gulf South Pipeline canal. The

Central Lock Complex (CL1), which is the proposed HNC Lock, will optimize the sector

gates’ operation for environmental benefits, keeping them closed year-round. This would

hold water back, moving freshwater onto central Terrebonne marshes. When the sector

gates are closed boat traffic would travel through the lock chamber. For vessels

exceeding the lock size, an industry traffic management system will be developed to

opportunistically open the sector gates to let these vessels pass.

Project measures in the eastern portion of the project area associated with the Eastern

Culvert #5 (EC5) include: a soil berm, culverts and dredging. East Dredge Channel #5

(ED5) is a 1000-ft. channel to connect the GIWW to EC5. East Dredge Channel #3

(ED3) is a 16,500-ft. expansion of Grand Bayou to deliver fresh water into the Grand

Bayou Basin. ED 7 is a 13,000-ft. extension of ED 3 further into the Grand Bayou Basin.

Along Grand Bayou at the point where ED3 becomes ED7, five 5’ x 5’ box culverts

(EC2) will convey flow to the west through an existing levee along the alignment of the

existing Grand Bayou which will be dredged (ED6) for a length of 16,800 feet to freshen

eastern Grand Bayou marshes. Related to this is a 13,000-ft.linear soil berm (EM 1)

which will be placed perpendicular to tidal flow to prevent salt water intrusion into the

eastern Grand Bayou marshes. Below ED 7 on Grand Bayou, ten 5’ x 5’ flap gated box

culverts with variable crest outfall (EC3) will be installed to convey fresh water, prevent

saltwater intrusion, and allow control of water levels in marshes to northwest. Further to

the south, another 37,000-ft. linear soil berm (EM3) will be placed perpendicular to tidal

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flow to slow fresh water movement to the gulf and prevent saltwater intrusion from the

south in an effort to stabilize the marshes in lower Grand Bayou basin.

Additionally, in the project’s eastern area, several measures will be taken to improve

fresh water conveyance from the GIWW down St. Louis Canal. Two 8' x 8' 8-barrel flap

gated culverts (EC6 and EC7) will allow water under roads that are currently constricting

flow into St. Louis Canal. Planned dredging of St. Louis Canal for 56,300-feet (ED2)

will allow water movement from the GIWW through EC6 and EC7 to the Grand Bayou

basin. Removal of a rock weir (EX1) and a soil plug (EX 2) will increase water

movement through the basin to better distribute fresh water from Grand Bayou and St.

Louis Canal. Excavations of two gaps (EG1 and EG2) in canal spoil banks will facilitate

better fresh water movement in the respective areas. A boat bay 20' wide with an invert

of -5' (EP7) will be placed in Cutoff Canal on the north bank of Bayou Pointe au Chien to

retain fresh water in marshes to the north and prevent saltwater intrusion from the south.

The NER Plan meets most planning objectives. The NER Plan will decrease the rate of

decline of the wetlands to ensure their ability to provide geomorphic and hydrologic form

and function for the 50-year period of analysis. Marsh habitat for essential fish and

wildlife species will be sustained, mimicking as closely as possible conditions which

occur naturally in the area. The alternatives were designed to work with the natural,

fluid, soft environment of coastal Louisiana. Without this project, the Terrebonne

Marshes will continue to decline over the next 50 years.

Overall, the NER Plan would reduce land loss in the project area from 101,570 acres to

91,915 acres, thus preventing the loss of 9,655 acres of marsh habitat over the 50-year

period of analysis. Alternative 2 would yield 3,220 AAHUs over the No Action

Alternative.

This plan, by increasing the fresh water and nutrient input into a freshwater-deprived

system, would let the ecosystem “self-regulate,” letting natural wetland processes take

over. Per ER 1105-2-100 Section E-30, “The objective of Civil Works ecosystem

restoration is to restore degraded significant ecosystem structure, function, and dynamic

processes to a less degraded, more natural condition. However, partial restoration may be

possible, with significant and valuable improvement made to degraded ecological

resources.” The Terrebonne Marshes provide important geomorphic, hydrologic, and

habitat functions in the study area. Loss of these functions would have impacts beyond

the project study area.

The significance of the ecosystem outputs plays an important role in ecosystem

restoration evaluation per section E-37 of ER 1105-2-100. The outputs are institutionally

recognized. This project is listed in the Louisiana State Master Plan, and is designated as

a critical near term feature in the LCA Ecosystem Restoration Study. There is public

support in Louisiana for this project, with specific emphasis on beginning construction as

soon as possible.

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The outputs are technically recognized. Examples of technical significance are:

• Scarcity: Louisiana’s coastline represents 90% of the wetlands in the contiguous

United States and is currently disappearing at an alarming rate. This unique and

scarce habitat has high fish and wildlife values.

• Representativeness: The RP will greatly benefit existing coastal marshes in the

project area.

• Status and Trends: The project area is declining and imperiled. While the project

cannot stop the natural processes of sea level rise, subsidence, and storm-caused

erosion, the project can greatly slow down the disappearance of these landforms

by decreasing the rate of decline of wetland habitat in the coastal system.

• Connectivity: The Terrebonne Marshes has one of the largest expanses of critical

fresh water marsh habitat in Louisiana. The Terrebonne Marshes are also a

valuable stopover habitat for migratory birds. With the loss of these marshes, this

valuable stopover habitat for migratory birds is lost as well.

• Limiting Habitat: NMFS has designated all marsh habitats in the project area as

EFH for Brown Shrimp, White Shrimp, Gulf Stone Crab, and Red Drum.

3.6.2 Design, Environmental, and Construction Considerations of the NER Plan

Major Project Considerations:

• Continued access of Louisiana Highway 24 and 57 will be maintained during

construction.

• Construction of all structural measures will be done in accordance with industry

standards.

• Construction of the channel conveyance systems will be done in accordance with

industry standards.

• Berm construction features will make use of beneficial spoil systems and will be

done in accordance with industry standards.

• Any excess spoil from the channel conveyance systems will go into marsh

creation. These marsh creation features will be built to industry standards.

• Construction of features in the vicinity of the twin span bridge conducted as to not

compromise the integrity of the bridges.

3.6.3 Real Estate Requirements of the NER Plan

The NER Alternative (Alt 2) involves construction of 56 structures and other water

management features and the opportunistic operation of the Houma Navigation Lock

complex. A total of approximately 2,851 acres is required for this project. The total

acreage required for water control structures is approximately 8.8 acres. Approximately

5.7 acres is necessary for alteration of canals through placement or removal of plugs and

the placement of gaps. Approximately 1,437.7 acres are necessary for the improvement

of channels through dredging, the use of culverts, and shoreline protection.

Approximately 797.6 acres are required to accommodate marsh restoration efforts. The

construction of a weir will require approximately 1.4 acres. Approximately 15.3 acres

are necessary for the improvement of 2 levees. An additional 584.5 acres are required for

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temporary work area. In addition to the estates acquired to accommodate project

features, approximately 222.3 acres of oyster leases are anticipated to be directly

impacted and, therefore, must be acquired. There is no acquisition of real estate interests

proposed specifically to protect the benefits area of the project (approximately 1 million

acres). Further information regarding real estate requirements may be found in Appendix

J, Real Estate Plan.

3.6.4 Operations and Maintenance Considerations of the NER Plan

All features for the NER Plan were considered for Operational Cost and Maintenance

Cost. Items that require painting, periodic inspections and debris removal were

considered features that will have annual cost to them and have been priced accordingly.

Features that consist of dredging or berm type work are considered as having no

maintenance cost. The multipurpose utilization of the HNC Lock complex for

environmental benefits operating plan will be further refined in coordination with the

development of the operating plan under Morganza to the Gulf. Some of the operation

and maintenance costs may be borne by the LCA ARTM non-Federal sponsor if the

multipurpose operation of the lock increases these costs over the Morganza to Gulf

operation and maintenance costs. Due to the uncertainties associated with the final design

and costs of this feature under the Morganza to the Gulf authority, these costs could not

be determined at this time.

Operation of the HNC lock and sector gate will involve closure of the sector gate year

round. Normal vessel traffic will pass through the lock. A few times each year, large

vessels that will not fit in the lock will need to pass through the structure. These vessels

will schedule openings of the sector gate portion of the structure. After the vessel passes,

the sector gates will again be closed.

Sluice gates located within the HNC lock structure will be open year round with the

exception of storm event conditions. Requirement for modification of the operational

scheme of the sluice gates will be assessed through adaptive management and

monitoring.

Features CLV1 and CLV2 will require maintenance until they are replaced or upgraded

by planned levees built by others.

All other structures included in the NER plan were assumed to be open for all conditions

during the alternatives analysis. These structures were designed with adaptive

management in mind and have various methods of being closed. Using the structures to

prevent salinity intrusion was another designed purpose. Operational plans for these

structures will be determined during PED.

3.6.5 Monitoring Plan and Adaptive Management

For the ARTM project, there are a number of uncertainties associated with ecosystem

function and how the ecosystem components of interest will respond to the restoration

project. For example, there is uncertainty in whether or not increasing the flow of fresh

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water to area marshes with little associated sediment will result in the predicted level of

benefits. It is believed that increased freshwater will benefit study area marshes, but

similar projects that could be used as verification do not currently exist. In addition,

there are associated uncertainties about the best design and operation for the project.

Using an adaptive management approach during project planning provided a mechanism

for building flexibility into project design and for providing new knowledge to better

define anticipated ecological responses. This also enabled better selection of appropriate

design and operating scenarios to meet the project objectives. Additionally, an adaptive

management approach will help define project success and identify outcomes that should

realistically be expected for the project.

An Adaptive Management Program for the ARTM project is needed to ensure proper

implementation of adaptive management. The Program will also facilitate coordination

of projects within the LCA Program and coordination among PDTs, the LCA Science and

Technology Program, and LCA Program Management. The LCA Adaptive Management

Planning Team will lead all LCA project and program adaptive management

recommendations and actions. This team is responsible for ensuring that monitoring data

and assessments are properly used in the adaptive management decision making process.

If this team determines that adaptive management actions are needed, the team will

coordinate a path forward with project planners and project managers. Other PDT

members may be solicited as needed; for instance, if the adaptive management measure is

operational, Operations and Hydraulics representatives might be asked to participate.

The LCA Adaptive Management Planning Team is also responsible for project

documentation, reporting, and external communication. Coordinated adaptive

management between ARTM and the Morganza to Gulf Project will be necessary and is

recommended.

Independent of adaptive management, an effective monitoring program will be required

to determine if the project outcomes are consistent with original project goals and

objectives. The power of a monitoring program developed to support adaptive

management lies in the establishment of feedback between continued project monitoring

and corresponding project management. A carefully designed monitoring program is a

central component of the ARTM adaptive management program (see Appendix I

Adaptive Management/Monitoring Plan). The ARTM monitoring plan currently calls for

the following pre- and post-project monitoring:

• Annual imagery-based habitat classification to assess land: water trends and

habitat distribution

• Annual vegetation monitoring at 24 stations to assess changes in vegetation

communities

• Semi-annual sediment accretion and elevation sampling at 24 stations in the

project area to assess elevation trends

• Utilization of 24 water gauging stations in the project area to assess salinity,

temperature, discharge, stage, etc.

• Collection of suspended sediment and nutrient data at 12 gauging stations in the

project area

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Project monitoring is the responsibility of the CPRA and the USACE. However, because

of the need to integrate monitoring for programmatic adaptive management, extensive

agency coordination is required. A monitoring workgroup, lead by the LCA Science and

Technology Program and the U.S. Geological Survey, will be responsible for ensuring

that project-specific monitoring plans are technically competent and appropriately

integrated within a system-wide assessment and monitoring plan (SWAMP).

The results of the monitoring program will be communicated to an Assessment Team

(AT) that will use the information to assess system responses to management, evaluate

overall project performance, construct project report cards, and recommend modifications

(i.e., adaptation) of the ARTM project as appropriate.

3.7 Locally-Preferred Plan

The Alternative 2 Plan is supported by the non-Federal sponsor and therefore the locally

preferred plan (LPP) is identified as Alternative 2.

3.8 Environmentally Preferable Alternative

Based on the evaluation conducted as part of this EIS it has been determined that

Alternative 3 is the environmentally preferable alternative. This alternative focuses on

increasing the fresh water supply from the GIWW to the Terrebonne marshes. Existing

fresh water would be more efficiently distributed and flows would be increased where

possible. Although this alternative has a greater environmental benefit over the

Recommended Plan, these benefits (106 AAHU) are not justified by the increased costs

($13,650 per AAHU). Therefore Alternative 2, not 3, was determined to be the NER Plan

based on the CE/ICA analysis.

3.9 Plan Selection – Recommended Plan

The Recommended Plan (RP) is the NER Plan, Alternative 2. A description of the NER

plan can be found in Section 3.6, above.

3.9.1 Effectiveness of Recommended Plan in Meeting Goals and Objectives

The RP/NER plan is an effective alternative at meeting most of the Goals and Objectives

of the alternatives evaluated. The RP restores some of the functional deltaic processes

that have been impaired resulting in a degraded condition. The RP fits within the current

cost and scope of the authorization. The first objective was to prevent, reduce, and/or

reverse future wetland loss in the study area. The RP reduces future wetland loss more

cost effectively than any other alternative in the final array of alternatives. The second

objective was to achieve and maintain characteristics of sustainable marsh hydrology.

The RP reduces future wetland loss more cost effectively than any other alternative in the

final array of alternatives. The third objective was to reduce salinity levels in the project

area. The RP accomplishes this objective through various robust measures and in a cost

effective manner. The fourth objective was to increase sediment and nutrient load to

surrounding wetlands. Although the RP will deliver nutrients to the surrounding

wetlands, none of the final alternatives in the final array will deliver sediment to the

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surrounding wetlands. The fifth objective was to increase residence time of fresh water in

the study area. The RP accomplishes this objective as effectively as any of the

alternatives in the final array. The final objective was to sustain productive fish and

wildlife habitat. The RP will demonstrably accomplish this objective. The overall goal of

the study was to reduce the current trend of degradation of the Terrebonne marshes, so as

to contribute towards achieving and sustaining a coastal ecosystem that can support and

protect the environment, economy, and culture of southern Louisiana and thus the Nation.

The RP accomplishes this goal by meeting all but one partial objective.

3.9.2 Effectiveness of Recommended Plan in Meeting Environmental Operating

Principles

The U.S. Army Corps of Engineers has reaffirmed its commitment to the environment by

formalizing a set of "Environmental Operating Principles" applicable to all its decisionmaking and programs. These principles foster unity of purpose on environmental issues,

reflect a new tone and direction for dialogue on environmental matters, and ensure that

employees consider conservation, environmental preservation and restoration in all Corps

activities.

Sustainability can only be achieved by the combined efforts of federal agencies, tribal,

state and local governments, and the private sector, each doing its part, backed by the

citizens of the world. These principles help the Corps define its role in that endeavor. By

implementing these principles, the Corps will continue its efforts to develop the

scientific, economic and sociological measures to judge the effects of its projects on the

environment and to seek better ways of achieving environmentally sustainable solutions.

The principles are being integrated into all project management process throughout the

Corps.

The principles, as follows, are consistent with the National Environmental Policy Act, the

Army Strategy for the Environment with its emphasis on sustainability and the triple

bottom line of mission, environment and community, other environmental statutes, and

the Water Resources Development Acts that govern Corps activities.

1. Strive to achieve environmental sustainability. An environment maintained in a

healthy, diverse and sustainable condition is necessary to support life.

2. Recognize the interdependence of life and the physical environment. Proactively

consider environmental consequences of Corps programs and act accordingly in all

appropriate circumstances.

3. Seek balance and synergy among human development activities and natural systems by

designing economic and environmental solutions that support and reinforce one another.

4. Continue to accept corporate responsibility and accountability under the law for

activities and decisions under our control that impact human health and welfare and the

continued viability of natural systems.

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5. Seeks ways and means to assess and mitigate cumulative impacts to the environment;

bring systems approaches to the full life cycle of our processes and work.

6. Build and share an integrated scientific, economic, and social knowledge base that

supports a greater understanding of the environment and impacts of our work.

7. Respect the views of individuals and groups interested in Corps activities, listen to

them actively, and learn from their perspective in the search to find innovative win-win

solutions to the nation's problems that also protect and enhance the environment.

The formulation of all alternatives considered for implementation met all of the

principles. However, as a function of the entire LCA program, the only principle not

meet fully is EOP #1 – Sustainability. Sustainability is a goal of any Corps project. This

project, as a part of the comprehensive coastal ecosystem restoration project for coastal

Louisiana, is just one part of many pieces that in their entirety, or cumulatively, lead to a

more sustainable end result. Therefore, as a standalone project, in the context of coastal

restoration, this project arguably falls short of EOP #1 because it does not address the

entire coast, but when added to other near-term, long-term, and other ongoing efforts, it

provides its share of reaching sustainability.

3.9.3 Compensatory Mitigation Measures

The project will provide positive ecosystem benefits. Temporary negative impacts to the

marsh associated with excavation of canals and management structures will be

compensated for by creation of new marsh and by reduction in the rate of marsh loss.

Efforts to avoid and minimize negative impacts to marsh habitat will be evaluated during

PED. No mitigation measures are needed.

3.9.4 Planning in a Collaborative Environment

EC 1105-2-409 outlines the purpose and intent of collaborative planning to address the

perceived shortcomings and criticisms of the procedures for the conduct of Corps water

resources planning and preparation of feasibility reports. This feasibility report, once

completed, will have met purpose and intent as outlined in EC 1105-2-409.

3.10 Risk and Uncertainty

3.10.1 Tropical Storm and Hurricane Damages

As with any ecosystem restoration project in the Louisiana Coastal Area, there will be

risk to features under Alternative 2. The associated risks with storm damage to features

in Alternative 2 were similar to all other alternatives considered in this study. Likewise,

the targeted resources of this restoration project are vulnerable to storm damage with no

action as well with any of the alternative plans. Implementation of Morganza to the Gulf

of Mexico Hurricane Protection Project will reduce risk of storm damage to some of the

resources and features of Alternative 2, but not eliminate these risks. Storm damage risks

to the ARTM project are not avoidable in the future, but may be manageable with

adaptive management techniques.

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3.10.2 Relative Sea Level Rise

Effectiveness of project features will be influenced by the rate of relative sea level rise

(RSLR) within the project area. RSLR values were calculated according to the latest

USACE guidance, EC 1165-2-211. This Engineering Circular provides curves for three

different sea level rise scenarios. The first uses the eustatic sea level rise rate plus the

local subsidence rate, which is determined using observed gage data. This is referred to

as the low RSLR rate. The second and third curves utilize sea level rise projection curves

for intermediate and high sea level rise developed by the Intergovernmental Panel on

Climate Change. These values are added to local subsidence rates to determine the

intermediate and high RSLR rates.

For this study all alternatives were analyzed using the low RSLR. Intermediate RSLR

rates were modeled for Alternative 3. This effort showed a reduced effectiveness for this

alternative of 66%. Due to the similarities of alternatives, the relative reduction in

effectiveness of all alternatives would be similar. While the effectiveness would be

reduced, the RP/NER plan would still provide benefits under the intermediate RSLR

scenario.

At the high RSLR rate, marsh collapse is predicted to begin in 2017, when RSLR rate

reaches 10 mm/yr. This rate represents a threshold believed to initiate rapid marsh

collapse as observed by Nyman et al. (2006). After 10 years, in 2027, the collapse would

be complete and the marsh would be gone. None of the alternatives would prevent marsh

collapse at the high RSLR rate. The results of this analysis are presented in Table 3.10.

Risk to the project due to RSLR cannot be calculated because the three RSLR rates are

based on future scenarios that do not have probabilities assigned to them. Since the

benefits of this project are sensitive to RSLR, the importance of adaptive management of

the project is increased. All structures, with the exception of the boat bay weir WW2,

will be constructed with some method of flow control to allow for adaptive management.

Operating machinery for all structures within this project will be constructed to an

elevation that they are all operable under the intermediate RSLR rate. This will provide

added flexibility to retain benefits longer under a range of RSLR.

Table 3.10 - Relative sea level rise analysis results for Alternative 3

RSLR Rate RSLR (ft) Net Acres

Net

AAHU

Low 1.89 10,308 3325

Intermediate 2.23 1,913 1126

High 3.73 0 0

3.10.3 Real Estate

Although the ARTM project features may cause slight increases in water elevations at

certain locations periodically, no substantial damage to private property is anticipated to

occur. The majority of the areas anticipated to experience slight increases in water

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elevations are marshlands. All existing viable uses of the marshlands are not expected to

be detrimentally affected by the periodic change in water elevation. All developed areas

within the project area are protected by levees and/or ridges. Therefore, the slight and

periodic increase in water levels is not anticipated to impact any developed areas. The

ARTM project features are designed to modify existing artificial flow and drainage

patterns in order to better approximate the patterns that used to naturally occur. The

ARTM project features are not predicted to significantly increase the magnitude or

frequency of inundation that will receive increased freshwater flows. Any increase in

water levels within the project area is directly related in increased water stages in the

Atchafalaya River. Therefore, flowage easements are not necessary within the project

area.

The benefited area of the ARTM project is approximately 1,000,000 acres, the majority

of which is marshlands. Any activity that may have a detrimental effect to the benefits

area of the project is regulated. Therefore, the risks over time would be minimal - aside

from uncontrollable forces such as nature (hurricanes, etc.). The types of activities that

could be considered risks (oil/gas surface exploration, excavation and fill activities, etc.)

are currently regulated by the Louisiana Department of Natural Resources, Office of

Coastal Management, under Title 43, Chapter 7 of the Louisiana Administrative Code.

Specifically, Subchapter C, Section 723.A.2. requires permits for dredging or filling,

urban developments, energy development activity(exploration and transmission of

oil/gas), mining activities(surface & subsurface), surface water control, shoreline

modification, recreational developments, industrial development, drainage projects and

"any other activities or projects that would require a permit or other form of consent or

authorization from the U.S. Army Corps of Engineers, the Environmental Protection

Agency, or the Louisiana Department or Natural Resources." Additionally, activities in

the marshes (wetlands) are regulated by Section 404 of the Clean Water Act under the

purview of the USACE. Certain other activities are regulated by the U.S. Fish and

Wildlife Service, the National Marine Fisheries Service, the EPA, and the Louisiana

Department of Environmental Quality.

More detailed information regarding real estate can be found in Appendix J, Real Estate

Plan.

3.10.4 Combinations of Risks

Due to risks arising from storm damages, relative sea level and anthropogenic

modifications to hydrology, there is an underlying unquantifiable uncertainty to the future

viability of the Terrebonne marsh system. There is a risk that the targeted ecological

resources in this study may continue to decline and possibly become almost non-existent

in the project area. Alternative 2 is the first step in the critical near-term to manage these

risks in a systematic approach and will certainly need to be adaptively managed over the

project lifespan.

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3.10.5 Implementation of the Houma Navigation Canal Lock Complex

The RP/ NER plan relies on the operation of the Houma Navigation Canal Lock Complex

for environmental purposes after 2025, as do all the alternatives considered with the

exception of the no action plan. The HNC lock complex is a feature of the Morganza to

the Gulf of Mexico Hurricane Protection Project. The lock complex ties into adjacent

earthen levees to reduce the risk of hurricane storm surge traveling up the HNC; the 100-

year elevation of the structure is currently estimated to be between 24’ and 26’ elevation

(NAVD 88). The lock complex includes a 110’ x 800’ lock, an adjacent 250’ wide sector

gate and a dam closure. For added flexibility, there are ten sluice gates in the t-wall

sections of the lock complex that can be used for drainage/circulation when the sector

gate is closed. Each gate is 5 ft tall by 10 ft wide, with the top of the gate opening at

elevation -2.0 ft. For the purposes of this study, it was assumed that the sluice gates

would be open any time the sector gates were closed, with the exception of storm

conditions.

This LCA study proposes the development of an operational plan for the lock complex

structure authorized under Morganza to the Gulf in order to maximize potential

environmental benefits, both in terms of avoiding saltwater intrusion and optimizing flow

distribution. The proposed action with a constructed lock complex (which comprises the

Future-Without-Project condition for the LCA study after 2025) is to operate it in such a

way that freshwater from the GIWW “escaping” down the Houma Navigation Canal

could be redirected into the surrounding wetlands.

The modified operation of the lock complex, however, may prove to be a challenge

because of the effort involved in opening and closing the floodgates. The lock itself will

be operated only when the floodgates are closed to reduce salinity within the channel.

Once closed, the floodgates would force water down other waterways (such as Bayou

Grand Caillou). Saltwater intrusion would be halted at the gate, and freshwater flows

would increase in other waterways. If the HNC Lock is not constructed by 2025, the

benefits of its operation would be lost and other benefits from LCA-ARTM from 2025

onward could be altered. Additionally, since the operations plan for the HNC Lock

Complex has not been finalized, the FWOP condition could be modified. This could also

alter the benefits after the lock is constructed.

In order to determine the potential impacts of varying completion schedules and

operational plans for the HNC Lock Complex on the benefits accrued with each LCAARTM alternative, separate hydraulic model results and WVA model results would have

to be generated for each new scenario. Given the scale of this undertaking and the

compressed schedule associated with the LCA-ARTM study, additional model runs to

clarify these impacts were not feasible. In lieu of additional model runs, one method of

estimating the impacts on project benefits of the Morganza to the Gulf Project not being

implemented would be to subtract the AAHUs associated with the modified operation of

the lock complex from all of the alternatives that include it as a measure. Alternative 7

consisted of only one measure, the modified operation of the lock complex, and resulted

in the generation of 243 AAHUs. Therefore, the assumption could be made that the other

action alternatives, all of which included modified lock operation as a measure, would

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have their benefits reduced by 243 AAHUs were the lock complex not constructed at all

during the 50-year period of analysis. This is not necessarily an accurate assumption

since project features do not perform completely independently from other project

features but rather interact synergistically or antagonistically in hydraulically complex

ways. Therefore, the modified operation of the lock complex may contribute more or less

than 243 AAHUs to the other action alternatives. However, this methodology should

provide a general idea of the scale of the impact that the removal of the feature would

have on the benefits accrued. Following this logic, Table 3.11 can serve as a guide to the

degree of sensitivity that the project would have to changing Morganza to the Gulf

completion schedules. Cost effectiveness and incremental cost analysis performed using

these estimated AAHUs revealed that Alternative 2 would still be selected as the NER

Plan and RP.

Table 3.11. Estimates of Project Benefits without HNC Lock Complex Implementation.

Alternative Benefits with Lock

Complex Implementation

in 2025 (AAHUs)

Benefits without Lock

Complex Implementation

(AAHUs)

Alternative 2 3,220 2,977

Alternative 3 3,325 3,082

Alternative 4 4,258 4,015

Alternative 5 4,719 4,476

Alternative 6 776 533

Alternative 7 243 0

Alternative 8 1,214 971

In addition to potential impacts that Morganza to the Gulf could have on the LCA-ARTM

study, features of the LCA-ARTM study may impact Morganza to the Gulf features. The

proposed change in operation of the HNC lock complex, in addition to other features

associated with LCA-ARTM, could have design implications for features associated with

the Morganza to the Gulf Project. Increased volumes of water directed into areas that

drain through proposed Morganza to the Gulf water control structures may require

adjustments to the designed structure sizes in order to accommodate more flow. This will

require continued coordination between the two studies to ensure compatibility. In

addition, modified operation of the HNC lock complex may result in increased O&M

costs for the flood gate and lock. The degree to which O&M costs would increase

remains undetermined at this time. The increase in O&M costs would be the

responsibility of CPRA, the non-Federal sponsor.

3.10.6 Project Benefits

Uncertainty exists with respect to ecosystem function and how the ecosystem

components of interest will respond to the restoration project. For example, there is

uncertainty in whether or not increasing the flow of fresh water and nutrients to area

marshes with little associated sediment will result in the predicted level of benefits. It is

believed that increased freshwater will benefit study area marshes, but similar projects

that could be used as verification do not currently exist. In addition, there are associated

uncertainties about the best design and operation for project features. Robust monitoring

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and adaptive management will help to ensure project success and identify outcomes that

should realistically be expected for the project.

There is also uncertainty as to the magnitude of benefits that will be accrued from

beneficial use of dredged material. For purposes of impact analysis associated with

dredge features for all alternatives, the assumption was made that the dredge channel

itself and the adjacent disposal site would result in marsh impacts. In reality, dredged

material will be used beneficially to create marsh habitat to the maximum extent

practicable. However, the exact nature of the dredged material and its utility in marsh

creation, the locations of marsh creation sites, and the acreage of created marsh habitat

will not be determined until a later date, during pre-construction engineering and design.

Therefore, the aforementioned assumptions were necessary in order to complete the

impact analysis for project features. In light of this, the estimates of negative impacts to

marsh should be viewed as maximums as they should be offset at least in part by

beneficially using dredged material during construction. Further environmental analysis

and documentation, including updates to the Section 404(b)(1) evaluation (see Appendix

D), will be prepared during pre-construction engineering and design to address changes

in disposal locations and associated benefits.

Finally, there is uncertainty with regard to fisheries access impacts on project benefits

associated with the Grand Pass weir (WW2), the Robinson Canal plug (CP1), the Cutoff

Canal plug (EP7), and the operation of the HNC Lock Complex (CL1). Inclusion of

fisheries access impacts in the calculation of AAHUs may have resulted in negative

AAHUs for all alternatives, despite net gains in wetland acreages. These measures are

designed to correct significant hydrologic alterations on man-made canals which are

thought to be significant causes of wetland degradation and loss and which resulted in

artificially increased fisheries access. In addition, other natural and man-made

waterways exist for fisheries access. Therefore, the decision was made to eliminate this

potential impact when calculating benefits associated with each alternative. Potential

modifications to this methodology are being investigated by USFWS in consultation with

NMFS, LDWF, and other interested natural resource agencies.

3.10.7 Future Analysis

In addressing the recommendations of the USFWS for further analysis and coordination

during pre-construction engineering and design (see Section 7.2.1), the following will be

undertaken:

• Additional hydrologic modeling, benefits analysis, and cost effectiveness analysis

of various sized and designed enlargements of Grand Bayou Canal/Bayou L’Eau

Bleu (measures ED3, ED5, ED6, and ED7) to avoid unnecessary construction

impacts and unnecessary canal-induced saltwater intrusion impacts, to include

efforts to assess project-related effects of reduced freshwater inflows to the

Barataria Basin

• Additional hydrologic modeling, benefits analysis, and cost effectiveness analysis

of various sized and designed enlargements of St. Louis Canal (measure ED2) to

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avoid unnecessary construction impacts and unnecessary canal-induced saltwater

intrusion impacts

• Additional hydrologic modeling, benefits analysis, and cost effectiveness analysis

related to the multi-purpose operation of the HNC Lock Complex to include

assessment of the adequacy of the existing model grid, re-examination of model

results for unaccounted-for HNC flows, inclusion of the Falgout Canal structures,

review of the predicted Lake Boudreaux salinity trends, and assessment of

alternative sluice gate operations on the HNC Lock

• Inspection of proposed work sites for the presence of wading bird nesting colonies

and bald eagles during the nesting season

• Sampling and testing of material to be dredged and determination of locations for

beneficial use of dredged material

• Development of operation plans for water control structures

• Coordination with Louisiana Department of Wildlife and Fisheries

In addition to the above analyses recommended by USFWS, additional hydrologic

modeling will be conducted on dredge feature WD2 in order to address concerns from the

public regarding saltwater intrusion and bank stability.

These efforts will be coordinated with the USFWS and other interested natural resource

agencies. The results of these additional analyses will be disclosed to the public and

supplemental NEPA documentation will be prepared, as appropriate.

3.11 Implementation Requirements

3.11.1 Schedule

At this time the implementation schedule for the NER/RP is based on MII cost estimation

durations. This implementation schedule is tentative and may change to be accelerated,

especially if a larger dredge is used than is currently accounted for in the cost estimation.

See Appendix L for a more detailed breakdown of the construction schedule. See Table

3.12 for the project implementation schedule.

Table 3.12 Milestone Schedule

Milestones Schedule

Final Report August 2010

Division Engineer Notice August 2010

Washington Level Review August 2010

Execute Cost-Sharing Agreement for PED September 2010

State and Agency Review October 2010

Chief of Engineers Report December 2010

Begin Preconstruction Engineering and Design 2011

ASA and OMB Review 2011

ASA Report to Congress 2011

Complete Design Documentation Report 2012

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Complete Plans and Specifications 2012

Execute PPA 2012

Complete Real Estate Acquisition 2012

Advertise Construction 2012

Construction Start 2013

Complete Construction 2018

Turnover Project to Local Sponsor 2018

Initiate Monitoring and Adaptive Management During PED

Complete Monitoring and Adaptive

Management

2028

3.11.2 Implementation Responsibilities

The non-Federal sponsor shall, prior to implementation, agree to perform all of the local

cooperation requirements and non-Federal obligations. Local cooperation requirements

and non-Federal sponsor obligations include, but are not necessarily limited to:

a. Provide a minimum of 35 percent of total project costs as further specified below:

(1) Enter into an agreement which provides, prior to execution of the

project partnership agreement, 25 percent of design costs;

(2) Provide, during the first year of construction, any additional funds

needed to cover the non-Federal share of design costs;

(3) Provide all lands, easements, and rights-of-way, including those

required for relocations, the borrowing of material, and the disposal of dredged or

excavated material; perform or ensure the performance of all relocations; and

construct improvements required on lands, easements, and rights-of-way to enable

the disposal of dredged or excavated material that the Government determines to

be necessary for the construction, operation, maintenance, repair, replacement,

and rehabilitation of the project;

(4) Provide, during construction, any additional funds necessary to make

its total contribution equal to 35 percent of the total project costs allocated to the

project;

b. Provide the non-Federal share of that portion of the costs of mitigation and

data recovery activities associated with historic preservation, that are in excess of 1

percent of the total amount authorized to be appropriated for the project;

c. Not use funds provided by a Federal agency under any other Federal program,

to satisfy, in whole or in part, the non-Federal share of the cost of the project unless the

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Federal agency that provides the funds determines that the funds are authorized to be

used to carry out the study or project;

d. Not use project or lands, easements, and rights-of-way required for the project

as a wetlands bank or mitigation credit for any other project;

e. For as long as the project remains authorized, operate, maintain, repair,

replace, and rehabilitate the project, or functional portions of the project, including

mitigation, at no cost to the Federal Government, in a manner compatible with the

project’s authorized purposes and in accordance with applicable Federal and state laws

and regulations and any specific directions prescribed by the Federal Government;

f. Give the Federal Government a right to enter, at reasonable times and in a

reasonable manner, upon property that the non-Federal sponsor, now or hereafter, owns

or controls for access to the project for the purpose of inspecting, operating, maintaining,

repairing, replacing, rehabilitating, or completing the project. No completion, operation,

maintenance, repair, replacement, or rehabilitation by the Federal Government shall

relieve the non-Federal sponsor of responsibility to meet the non-Federal sponsor’s

obligations, or to preclude the Federal Government from pursuing any other remedy at

law or equity to ensure faithful performance;

g. Hold and save the United States free from all damages arising from the

construction, operation, maintenance, repair, replacement, and rehabilitation of the

project and any project-related betterments, except for damages due to the fault or

negligence of the United States or its contractors;

h. Perform, or cause to be performed, any investigations for hazardous substances

that are determined necessary to identify the existence and extent of any hazardous

substances regulated under the Comprehensive Environmental Response, Compensation,

and Liability Act (CERCLA), Public Law 96-510, as amended (42 U.S.C. 9601-9675),

that may exist in, on, or under lands, easements, or rights-of-way that the Federal

Government determines to be required for the initial construction, periodic nourishment,

operation, and maintenance of the project. However, for lands that the Federal

Government determines to be subject to the navigation servitude, only the Federal

Government shall perform such investigations unless the Federal Government provides

the non-Federal sponsor with prior specific written direction, in which case the nonFederal sponsor shall perform such investigations in accordance with such written

direction;

i. Assume, as between the Federal Government and the non-Federal sponsor,

complete financial responsibility for all necessary cleanup and response costs of any

CERCLA regulated materials located in, on, or under lands, easements, or rights-of-way

that the Federal Government determines to be necessary for the initial construction,

periodic nourishment, operation, or maintenance of the project;

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j. Agree that, as between the Federal Government and the non-Federal sponsor,

the non-Federal sponsor shall be considered the operator of the project for the purpose of

CERCLA liability, and to the maximum extent practicable, operate, maintain, and repair

the project in a manner that would not cause liability to arise under CERCLA;

k. Prevent obstructions of or encroachments on the project (including prescribing

and enforcing regulations to prevent such obstruction or encroachments) which might

reduce ecosystem restoration benefits, hinder operation and maintenance, or interfere

with the project’s proper function, such as any new developments on project lands or the

addition of facilities which would degrade the benefits of the project;

l. Keep and maintain books, records, documents, and other evidence pertaining to

costs and expenses incurred pursuant to the project, for a minimum of 3 years after

completion of the accounting for which such books, records, documents, and other

evidence is required, to the extent and in such detail as would properly reflect total costs

of construction of the project, and in accordance with the standards for financial

management systems set forth in the Uniform Administrative Requirements for Grants

and Cooperative Agreements to State and Local Governments at 32 Code of Federal

Regulations (CFR) Section 33.20;

m. Comply with Section 221 of Public Law 91-611, Flood Control Act of 1970,

as amended (42 U.S.C. 1962d-5), and Section 103 of the Water Resources Development

Act of 1986, Public Law 99-662, as amended (33 U.S.C. 2213), which provides that the

Secretary of the Army shall not commence the construction of any water resources

project or separable element thereof, until the non-Federal sponsor has entered into a

written agreement to furnish its required cooperation for the project or separable element;

n. Comply with all applicable Federal and state laws and regulations, including,

but not limited to, Section 601 of the Civil Rights Act of 1964, Public Law 88-352 (42

U.S.C. 2000d), and Department of Defense Directive 5500.11 issued pursuant thereto, as

well as Army Regulation 600-7, entitled "Nondiscrimination on the Basis of Handicap in

Programs and Activities Assisted or Conducted by the Department of the Army,” and all

applicable Federal labor standards and requirements, including but not limited to 40

U.S.C. 3141- 3148 and 40 U.S.C. 3701 – 3708 (revising, codifying, and enacting without

substantial change the provisions of the Davis-Bacon Act (formerly 40 U.S.C. 276a et

seq.), the Contract Work Hours and Safety Standards Act (formerly 40 U.S.C. 327 et

seq.) and the Copeland Anti-Kickback Act (formerly 40 U.S.C. 276c et seq.); and

o. Comply with all applicable provisions of the Uniform Relocation Assistance

and Real Property Acquisition Policies Act of 1970, Public Law 91-646, as amended (42

U.S.C. 4601-4655), and the Uniform Regulations contained in 49 CFR Part 24, in

acquiring lands, easements, and rights-of-way necessary for the initial construction,

periodic nourishment, operation, and maintenance of the project, including those

necessary for relocations, borrow materials, and dredged or excavated material disposal,

and inform all affected persons of applicable benefits, policies, and procedures in

connection with said Act.

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3.11.3 Cost Sharing

The State of Louisiana, acting through the CPRA, will be the non-Federal sponsor for the

Recommended Plan. In November 2008, the USACE and CPRA executed a single

Feasibility Cost-Share Agreement covering six Louisiana Coastal Area near-term plan

elements listed in Section 7006(e) of the Water Resources Development Act of 2007. The

six features each underwent a separate feasibility analysis and environmental compliance

analysis culminating in a single master feasibility document. The cost-share during the

feasibility phase was 50% Federal and 50% non-Federal; however, the individual

elements have been divided so that each entity has lead responsibility for preparing three

of the six report components. At the end of the feasibility phase the total cost for all

elements will have been shared on a 50/50 basis, yet for work on each individual element

during the feasibility phase the ratio of funds expended by either the Federal or nonFederal sponsor will be higher depending upon their level of responsibility. The Corps

has the technical planning lead for this particular LCA project element. Following the

feasibility phase, the cost share for the planning, design and construction of the project

will be 65% Federal and 35% non-Federal. The CPRA must provide all lands, easements,

rights-of-way, utility or public facility relocations, and disposal areas (LERRDs) required

for the project. The value of LERRDs would be included in the non-Federal 35% share.

Operation, Maintenance, Repair, Replacement and Rehabilitation (OMRR&R) of the

project would be a 100% CPRA responsibility. Additionally, project monitoring and any

Adaptive Management deemed necessary will be cost shared at 65/35 for the first 10

years of the project life.

Under current law, authority for the non-Federal sponsor to receive credit for

construction activities is limited. Section 7007(a) of WRDA 2007 authorizes the

Secretary to credit, "toward the non-Federal share of the cost of a study or project under

this title the cost of work carried out in the coastal Louisiana ecosystem by the nonFederal interest for the project before the date of the execution of the partnership

agreement for the study or project." In addition, section 7007(a) incorporates the

requirement of section 221 of the Flood Control Act of 1970, as amended, (42 U.S.C.

1962d-5b) that the Government and non-Federal sponsor must enter into a separate

agreement for any work that will be carried out prior to execution of the partnership

agreement. In other words, work undertaken by the non-Federal sponsor prior to (but not

after) execution of the project partnership agreement (PPA) is eligible for credit subject

to execution of a separate agreement covering such work before it is undertaken. For

design work that the non-Federal sponsor proposes to undertake, the Design Agreement

will serve as the required separate agreement. For construction work that the non-Federal

sponsor proposes to undertake, an In-Kind Memorandum of Understanding will be

required. Opportunities to enter into an In-Kind MOU for construction activities will

depend on the schedule for entering into the PPA for a project.

Section 7007(d) provides that credit afforded under section 7007 that is in "excess" of the

non-Federal cost share for a study or project authorized in Title VII of the Water

Resources Development Act of 2007 may be applied toward the non-Federal cost share

of any other study or project under that title. "Excess" credit will be applied only toward

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another study or project involving the same sponsor. In addition, "excess" credit will be

applied within project phases (i.e., study to study, design to design, and construction to

construction). At this time, it is anticipated that that there are limited opportunities for

the application of "excess credit" from other Title VII projects toward these projects.

Table 3.13 outlines the current cost estimates and distribution of costs between the

Federal and non-Federal interests. The Federal Government would provide 65% of the

first cost of implementing the Recommended Plan including Preconstruction Engineering

and Design (PED), construction, and construction management, which is estimated to

total $305,500,000. The State of Louisiana would be responsible for providing 35% of

the First Cost of implementing the Recommended Plan. The 35% share of the project

cost includes the State of Louisiana’s responsibility for providing all LERRDs. The

estimated costs are $97,500,000 in cash with $8,125,000 in LERRD credit respectively.

The State of Louisiana also would be responsible for OMRR&R of project features. The

operation and maintenance costs are anticipated to be minimal over the 50-year period of

analysis at an average annual cost of $72,000. The modified operation of the HNC lock

complex may increase the OMRR&R costs for the lock by an amount that cannot be

determined until the operating plan is further developed in coordination with the

Morganza-to-the-Gulf project. The CPRA would be 100% responsible for the

incremental increase in OMRR&R costs for the lock.

Table 3.13: Cost Sharing

LCA: Convey Atchafalaya River Water to Northern Terrebonne Marshes

RP Federal/non-Federal Cost Breakdown.

Project Feature Total Cost Non-Federal Federal

% Cost % Cost

First Cost of $284,200,000 35 $99,470,000 65 $184,730,000

Construction

LERRD Credit $10,700,000 $0

OMRR&R*

(average

$72,000 $72,000 $0

Annual)

Maintenance

Monitoring &

Adaptive

$21,300,000

Management

3.11.4 Environmental Commitments

Best management practices would be included in construction specifications and they

would be employed during construction activities to minimize environmental effects.

Many of these best management measures are required by Federal, State, or local laws

and regulations, regardless of whether they are specifically identified in this document or

not. Project implementation would comply with all relevant Federal, State, and local

laws, ordinances, regulations, and standards during the implementation of the preferred

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alternative. Implementation of the environmental commitments would be documented to

track execution and completion of the environmental commitments.

A summary of the environmental and related commitments made during the planning

process and incorporated into the proposed project plan include the following:

• Ensure construction contractors limit ground disturbance to the smallest extent

feasible.

• Use accepted erosion control measures during construction.

• Conduct a search for bald eagle, other raptors and colonial nesting wading bird

active nests within three-quarter of a mile from proposed disturbance activities

prior to construction. Appropriate protective measures and no-work distance

restrictions would be implemented to avoid or minimize nest disturbance if active

nests are identified.

• Contact pipeline and gas well companies prior to construction activities to

identify and avoid existing hazards.

• Implement best management practices and measures contained in erosion control

guidelines to control soil erosion from construction areas.

• Implement measures to control fugitive dust during construction.

• Implement a program to compensate for losses of archaeological sites (if any) that

would occur as a result of construction and operation of the proposed project.

• Implement the Monitoring and Adaptive Management Plan.

• Implement the recommendations of the USFWS for further modeling and analysis

of alternatives as detailed in Section 7.2.1 and Appendix B of this report.

3.11.5 Financial Requirements

3.11.5.1 Sponsorship Agreement

Prior to the start of construction, the State of Louisiana will be required to enter into a

Project Partnership Agreement (PPA) with the Federal Government and satisfy state laws

and all applicable regulations. In general, the items included in the PPA have been

outlined in the previous paragraphs.

3.11.5.2 Financial Analysis

It is expected that the CPRA will have the capacity to provide the required local

cooperation for the Recommended Plan. A project schedule and cost estimate will be

provided to the CPRA so that it may develop a financing plan. A standard cost share

percentage of 65% Federal and 35% non-Federal would be applied to the total first cost

of the project. The 35% share of the project cost includes the State of Louisiana’s

responsibility for providing all LERRDs.

Section 7007(b) of WRDA 2007 provides that "The non-Federal interest may use, and the

Secretary shall accept, funds provided by a Federal agency under any other Federal

program, to satisfy, in whole or part, the non-Federal share of the cost of the study or

project if the Federal agency that provides the funds determines that the funds are

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authorized to carry out the study or project." If the Mineral Management Services

determines in writing that funds it provides to the non- Federal sponsor under the Energy

Policy Act of 2005 (Coastal Impact Assistance Program - CIAP) and the Gulf of Mexico

Energy Security Act of 2006 (GOMESA) are authorized to be used to carry out the

Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of the Houma Navigation Lock projects, the non-Federal sponsor can use those

funds toward satisfying its local cooperation for the project, including the non-Federal

sponsor's acquisition of Lands, Easements, Relocations, Rights of-way and Disposals

(LERRDs) required for the project.

By letters dated July 2, 2009 and December 18, 2009, the Minerals Management Service

and the USACE established a process for the Minerals Management Service to provide

its written determination regarding the acceptability of the use of CIAP funds for LCA

studies, projects, and programs. That process provides that the Minerals Management

Services' written determination for a specific study, project, or program will take the form

of the grant award document for that activity.

3.11.5.3 Local Cooperation

The CPRA provided a letter of intent to serve as the non-Federal sponsor for the project

on August 9, 2010. A copy of the letter can be found in Appendix ??.

3.11.5.4 Project Management Plan

A Project Management Plan (PMP) for implementation of the Recommended Plan will be

prepared. The PMP will describe activities, responsibilities, schedules, and costs

required for the Plans and Specifications phase and construction of the project. The Plans

and Specifications phase will last for an estimated 24 months at a total estimated cost of

$23,423,000.

3.11.5.5 Procedures for Project Implementation

Future actions necessary for project approval and implementation are summarized as

follows:

1. The purpose of peer review, or in this case, Independent External Peer Review

(IEPR) is to ensure the quality and credibility of the Corps scientific information.

IEPR will be conducted during the official public review period of the draft integrated

feasibility report and EIS. Comments must be addressed before the document can be

made final.

2. The U.S. Army Corps of Engineers Mississippi Valley Division Commander will

review the final report and then issue a public notice announcing completion of the

final report. This is referred to as the Division Engineer’s Notice, or DE’s Notice.

3. The report will then be submitted to Headquarters, U.S. Army Corps of Engineers

(HQUSACE), and the Office of the Assistant Secretary of the Army for Civil Works

(ASA (CW)) for concurrent Washington level review.

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4. The 30-day state and agency review and coordination of the EIS will be ongoing

concurrently during the HQUSACE review.

5. Concurrent Washington level review by HQUSACE and ASACW will conclude with

a HQUSACE staff assessment, the 30-day state and agency review, review input by

the ASACW, HQUSACE final assessment, a field visit and meeting, if necessary, and

the documentation of report review prepared by HQUSACE.

6. The Washington level decision-making process will follow the decision-making

sequence of HQUSACE and ASACW, once the documentation of report review has

been completed. There will be a briefing, if necessary, for the Designated Senior

Representatives of Decision-Makers to resolve any outstanding issues. The Chief of

Engineers will provide his recommendations on the report to the ASACW, who will

provide the report and proposed recommendations to the Office of Management and

Budget (OMB) to obtain their views and comments on whether the proposed

recommendations are consistent with Administrative policies. Prior to the transmittal

of the report to the Congress, the Non-Federal Sponsor, the State of Louisiana,

interested Federal agencies, and other parties will be advised of any significant

modifications made to the recommendations and will be afforded an opportunity to

comment further.

7. Authorization of the project is provided by WRDA 2007; however, authorization and

construction is contingent upon the completion and acceptance of a Chief of

Engineer’s Report by December 31, 2010.

8. Funds could be provided, when appropriated in the budget, for Preconstruction

Engineering and Design (PED) upon issuance of the Division Engineer’s public

notice, announcing the completion of the final report and pending project funding

authorization. A Design Cooperation Agreement will need to be developed and

executed between the Federal Government and the State of Louisiana, whereby the

sponsor will provide 25% of the cost of PED studies.

9. The U.S. Army Corps of Engineers will complete final design and plans and

specifications for project construction.

10. Subsequent to appropriation of construction funds by Congress, formal assurances of

local cooperation in the form of a Project Partnership Agreement (PPA) will be

required from the State of Louisiana.

11. The State of Louisiana will be required to provide all real estate requirements for

project implementation.

12. Bids for construction will be advertised and contracts awarded.

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13. Upon completion of construction, the Corps’ acceptance from the contractor and

notice of construction completion for the project (or a functional portion of the

project) to the non-Federal sponsor will proceed or be concurrent with the delivery of

an O&M manual and as-built drawings. The State of Louisiana will be responsible

for OMRR&R of the project in accordance with guidelines provided by the U.S.

Army Corps of Engineers.

3.11.6 Views of Non-Federal Sponsor

The State of Louisiana fully supports the project. The state recognizes that the USACE's

position is that section 7007 does not authorize credit for work carried out after the date

of a partnership agreement. However, the state disagrees with the USACE position and

intends to continue to seek a change in law that would allow in-kind contribution credit

for work carried out after the date of a Project Partnership Agreement and that would

allow for such in-kind contributions credit to carry over between LCA Program

components (i.e., “excess” credit for work undertaken after signing of the project

partnership agreement for one project may be carried over for credit to another project).

Nevertheless, while the state is of the opinion that its view is consistent with the authority

and Congressional intent under WRDA 2007, the state fully intends to proceed with the

project under the Corps’ interpretation of current law and to meet all non-Federal

financial and other obligations outlined by the USACE in this report until such time as

the law is changed.

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4.0 AFFECTED ENVIRONMENT

This chapter describes the climate, geomorphic and physiographic setting, and the

historic and existing conditions for the following important resources: soils; coastal

vegetation; wildlife; fisheries; plankton; benthos; essential fish habitat (EFH); threatened

and endangered species; hydrology (including flow and water levels, and sediment);

water quality; recreation; public lands; cultural and historic resources; aesthetics; air

quality; socioeconomic and human resources (including population; infrastructure;

employment and income; navigation; oil, gas, and utilities; pipelines; commercial

fisheries; oyster leases; and flood control and hurricane protection). In addition, the

characterization of noise and hazardous, toxic, and radioactive waste (HTRW) in the

project area are presented.

A resource is considered important if it is recognized by statutory authorities including

laws, regulations, Executive Orders (EO), policies, rules, or guidance; if it is recognized

as important by some segment of the general public; or if it is determined to be important

based on technical or scientific criteria. The following sections discuss historic and

existing conditions of each important resource occurring within the project area.

4.1 Environmental Setting of Study Area

4.1.1 Location

The overall study area is located mostly in Terrebonne Parish in southeast Louisiana at

the northern edge of the Gulf of Mexico (Figure 4.1) and encompasses approximately

1,100 square miles (700,000 acres). A portion of Lafourche Parish between Bayou

Lafourche and Bayou Pointe au Chien is also included in the study area. Small portions

of St. Mary, St. Martin, and Assumption Parishes are also included. The study area is

approximately 55 miles wide from west to east and averages 20 miles across from the

north to south boundaries.

The study area lies within the Barataria-Terrebonne estuary. This estuary extends from

the west bank levees of the Mississippi River (north and east), to the East Guide Levee of

the Atchafalaya River (west), to the Gulf of Mexico (south), and to the town of Morganza

(north). The Barataria Basin covers about 1,551,800 acres while the Terrebonne Basin

covers an area of about 2,063,500 acres. The study area lies within the southern end of

the Terrebonne Basin and contains a complex of habitat types, including natural levees,

lakes, swamps, marshes, and bayous formed from sediments of abandoned Mississippi

River deltas. Elevations in the study area vary. Near Houma, the largest city in the area,

the elevation is approximately 10 feet National Geodetic Vertical Datum (NGVD). The

elevation along the bayou ridges is 4-5 feet NGVD and less than 1 foot NGVD along the

southern portion near the Gulf of Mexico.

The major streams located in the study area or that influence the study area are the

Atchafalaya River, Bayou du Large, Bayou Grand Caillou, Bayou Petit Caillou, Bayou

Terrebonne, Bayou Pointe au Chien, Bayou Lafourche, Bayou L’eau Blue, Grand Bayou,

Grand Bayou Blue, and Bayou Black. There are no scenic streams in the study area

designated under the Louisiana Natural and Scenic River System. The Houma

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Navigation Canal runs north and south from the GIWW to the Gulf of Mexico mainly

between Bayou du Large and Bayou Grand Caillou. The GIWW follows an east-west

path in the northern portion of the study area. These two waterways, along with the

natural channels in the area, have a strong influence on surface water in the area.

4.1.2 Climate

The climate of the study area is subtropical marine with long humid summers and short

moderate winters. The climate is strongly influenced by the water surface of the many

sounds, bays, lakes, and the Gulf of Mexico and seasonal changes in atmospheric

circulation. During the fall and winter, the study area experiences cold continental air

masses which produce frontal passages with temperature drops. During the spring and

summer, the study area experiences tropical air masses which produce a warm, moist

airflow conducive to thunderstorm development (USACE 2008). National Oceanic and

Atmospheric Administration data indicates that average annual rainfall for the area is

approximately 65 inches. The study area is also subject to periods of both drought and

flood, and the climate rarely seems to truly exhibit “average” conditions.

The study area is susceptible to tropical waves, tropical depressions, tropical storms and

hurricanes. These weather systems can cause considerable property and environmental

damage and loss of human life. Data obtained from the National Oceanic and

Atmospheric Administration (NOAA) Coastal Services Center indicate that the storm

centers of at least 38 tropical cyclones with a Saffir-Simpson Hurricane Scale of

Category 1 or higher have passed within 50 miles of the study area during the interval

1851-2008, and at least 54 such tropical cyclones have passed within 100 miles of the

study area during the same interval (Figure 4.2). The most recent tropical cyclones to

affect the study area were Hurricanes Katrina and Rita, which occurred in August 2005

and September 2005, respectively, and Hurricanes Gustav and Ike, which occurred in

September 2008. The area of marsh lost along the Louisiana coast as a result of

Hurricanes Katrina and Rita (192,000 acres) was over one third of the total wetland

losses predicted to occur by the year 2050 by the Coast 2050 Report (LCWCRTF and

WCRA 1998). Within the Terrebonne Basin, roughly 12,160 acres of wetlands were

converted to open water between 2004 and 2005 (Barras 2006), equal to 8.4% of the

losses predicted to occur by 2050.

Climate Change.

Engineering Circular 1165-2-211 requires consideration of impacts of sea level change

on all phases of USACE Civil Works programs and provides guidance for incorporating

the direct and indirect physical effects of projected future sea-level change in managing,

planning, engineering, designing, constructing, operating, and maintaining USACE

projects. It is important to distinguish between eustatic and relative sea level rise.

Relative sea level rise consists of eustatic or regional sea level rise combined with

subsidence. Eustatic sea level rise is defined as the global increase in oceanic water

levels primarily due to changes in the volume of major ice caps and glaciers, and

expansion or contraction of seawater in response to temperature changes. Regional sea

level rise may differ slightly from eustatic sea level rise in large, semi-enclosed water

bodies like the northern Gulf of Mexico. Regional sea level rise in the project area was

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determined to be approximately 0.75 feet/century. Subsidence is the decrease in land

elevations, primarily due to consolidation of sediments, faulting, groundwater depletion,

and possibly oil and gas withdrawal. Subsidence in the project area was calculated using

the two closest long-term gauges, located at Grand Isle and Eugene Island, and was

determined to be approximately 2.35 feet/century. Relative sea level rise affects project

area marshes by gradually inundating marsh plants. Marsh soil surfaces must vertically

accrete to keep pace with the rate of relative sea level rise or marshes eventually convert

to open water due to the depth of submergence. Direct and indirect impacts of regional

sea level rise and subsidence were incorporated into the planning of the ARTM project.

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Figure 4.1. Project Area.

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Figure 4.2. Historic Hurricane Storm Tracks within 100 Miles of the Project Area.

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4.1.3 Geomorphic and Physiographic Setting

The geology of the area is heavily influenced by the Mississippi River and its delta plain,

a complex of abandoned and active deltas of the Mississippi River. Three of four

abandoned delta complexes shaped Terrebonne and Lafourche Parishes as sediments

were deposited on the Pleistocene Prairie. The Mississippi River laid down sediments

from 100-200 meters thick at each delta (Penland et al. 1988). The abandoned deltas

were formed generally from the west to the east in chronological sequence starting about

9,000 years before present and ending less than 100 years ago (Sevier 1990). The most

recent sediments of an abandoned delta were laid down as part of the Lafourche delta.

After delta abandonment occurs, sediments slowly deteriorate as they subside under their

own weight. In addition, sea level has been rising throughout this time by about 5 to 8 m

(Mossa et al. 1990). Historically, the cycle of delta growth and destruction took about

5,000 years (Gosselink and Sasser 1991). However, because of a variety of factors (most

notably human), delta destruction is taking place in a few human generations rather than

thousands of years.

The Lafourche delta complex in the study area, which includes Bayou Terrebonne, Bayou

Black, Bayou Blue, Bayou Pointe au Chien, Bayous Grand and Petit Caillou, and Bayou

du Large, began forming some 3,500 years ago. Delta development ended when the

Mississippi River shifted to the east about 500 years ago to adopt its current

configuration. From that time until about 100 years ago, overflows from the Mississippi

River continued to maintain the Lafourche delta complex. The complex began to degrade

when Bayou Lafourche was closed off early in the twentieth century (Mossa et al. 1990).

The Atchafalaya River with its actively building delta is out of the study area, but its

flows influence the study area. It was formed in the sixteenth century when a meander of

the Mississippi River captured the Red River. It remained an insignificant river until late

in the nineteenth century when an enormous logjam at its upper end was cleared (Mossa

et al. 1990) and water could move unobstructed toward the Gulf of Mexico. The lower

Atchafalaya delta began forming in 1952 and it continues to develop across Atchafalaya

Bay.

According to Turner and Rao (1990) the driving factors in landscape changes include sea

level rise, geological compaction, a 50 percent reduction in sediment supply from the

Mississippi River since the 1950's, and hydrologic changes. Delaune et al. (1994),

Kuecher (1994), and Gagliano (1999) conclude that geological factors, such as

consolidation of deltaic sediments and active faulting, appear to be the underlying cause

for a majority of the land loss in coastal Louisiana. Hydrocarbon withdrawals may also

be a significant factor (White and Morton 1997) by activating faults that lead to

subsidence.

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Based on data from Gulf of Mexico gages, regional sea level rise is approximately 0.75

feet/century and based on gages at Grand Isle and Eugene Island, subsidence in the

project area is approximately 2.35 feet/century.

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4.2 Significant Resources

4.2.1 Soils and Waterbottoms

4.2.1.1 Historic and Existing Conditions

This resource is institutionally significant because of the Council on Environmental

Quality (CEQ) memorandum of August 11, 1980, entitled “Analysis of Impacts on Prime

or Unique Agricultural Lands in Implementing the National Environmental Policy Act

(NEPA);” Executive Order 11990 – Protection of Wetlands; and Agriculture and Food

Act of 1981 (Public Law 97-98) containing the Farmland Protection Policy Act (Public

Law 97-98; U.S.C. 4201 et seq.). This resource is technically significant because it is a

critical element of coastal habitats, and supports vegetation growth and open-water

benthic productivity. This resource is publicly significant because of the high value the

public places on wildlife and fisheries supported by the soils in the area.

The following information is taken from the Soil Survey of Terrebonne Parish, Louisiana

(McDaniel and Trahan 2007):

Terrebonne parish lies entirely within the south-central region of the Mississippi

River Delta Plain. It is made up of two major land resource areas (MLRA's).

MLRA 131, the Southern Mississippi Valley Alluvium, makes up about 24

percent of the area. MLRA 151, the Gulf Coast Marsh, makes up the remaining

76 percent of the parish. The soils of the natural levees formed in sediments

deposited by former channels of the Mississippi River and its distributaries on

the Atchafalaya and Lafourche Delta Complex. Loamy soils are dominant on

the high and intermediate parts of the natural levees, and clayey soils are

dominant on the lower parts of the natural levees and in backswamps. The

loamy soils, and the clayey soils that rarely flood, make up about 9 percent of

the total land area of the parish. They are used mainly for cropland, urban, and

industrial purposes. A few areas are in pasture and woodland. The clayey soils

on the lowest parts of the landscape are subject to occasional or frequent

flooding and make up about 6 percent of the total land area of the parish. They

are used mainly for timber production, pasture, recreation, and wildlife. Some

narrow, loamy, natural levee ridges in the southeastern and east-central parts of

the parish extend south into the Gulf Coast Marsh. These areas are subject to

occasional flooding during tropical storms and are used mainly for camps,

homesites, and activities associated with the seafood industry.

The remaining 85 percent of the land area of Terrebonne Parish consists mainly

of ponded, frequently flooded, and very frequently flooded, mucky and clayey,

fluid soils in marshes and swamps. They are used mainly as habitat for wetland

wildlife and for recreation. Some acreage of former marshes and swamps have

been protected, pumped-off, and drained and are used as pasture or for urban

use. Elevations range from about 14 feet above mean sea level along the natural

levee of Bayou Terrebonne in the northern part of the parish, to about 5 feet

below sea level in the former marshes and swamps that have been drained.

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About 75,000 acres in the survey area, or nearly 7 percent of the total acreage,

meets the soil requirements for prime farmland. Scattered areas of this land are

mainly in the northern parts of the survey area. All areas of this prime farmland

are used for crops. The crops grown on this land, mainly common

bermudagrass, improved bermudagrass, soybeans, wheat, sugarcane, bahiagrass,

and corn account for a significant amount of the county's total agricultural

income each year.

A recent trend in land use in some parts of the survey area has been the loss of

some prime farmland to industrial and urban uses. The loss of prime farmland

to other uses puts pressure on marginal lands, which generally are more

erodible, droughty, and less productive and cannot be easily cultivated.

The soils in the project area that fall outside of the Terrebonne Parish boundary share

characteristics and formative processes very similar to those of Terrebonne Parish as

described above (Figure 4.3).

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4.2.2 Hydrology

This resource is institutionally significant because of the National Environmental Policy

Act of 1969; Clean Water Act; Flood Control Act of 1944; Coastal Barrier Resources

Act; Rivers and Harbors Act of 1899; River and Harbor and Flood Control Act of 1970;

Watershed Protection and Flood Prevention Act; Submerged Land Act; Coastal Zone

Management Act; Safe Drinking Water Act; Estuary Protection Act; Resource

Conservation and Recovery Act (RCRA); Comprehensive Environmental Response,

Compensation, and Liability Act (CERCLA); and Executive Order 11988 Floodplain

Management. This resource is technically significant because Civil Works water

resources development projects typically impact (positively or negatively) the

interrelationships and interactions between water and its environment. This resource is

publicly significant because the public demands clean water, hazard-free navigation,

protection of estuaries and floodplains.

4.2.2.1 Flow and Water Levels

4.2.2.1.1 Historic and Existing Conditions

Historically, flows within the project area were driven by the Atchafalaya River and

Bayou Lafourche. Flows in the Atchafalaya had been increasing from 10 percent of the

combined Mississippi and Red River flow in the 1850s to 30 percent before the

construction of the Old River control structure. This structure maintains the split at 30

percent today. Bayou Lafourche was naturally closing before its connection with the

Mississippi River was closed in the early 1900s. With the closure of Bayou Lafourche,

the inflow of fresh water into the central and eastern portions of the project area was

limited to local inflow. The Bayou Black ridge restricted the flow of water along the

northern boundary of the project area, as it does today.

Since that time, the Atchafalaya Basin Floodway; GIWW; Atchafalaya River; Bayous

Chene, Boeuf, and Black Navigation Channel; Houma Navigation Canal; and Houma

area levees and pump systems, drainage canals, and access canals have altered the

hydrology of the project area.

Today, flows within the project area are generally driven by stages in the Lower

Atchafalaya River (LAR). Major flow channels within the project area are the

Atchafalaya River, the Gulf Intracoastal Waterway (GIWW), and the Houma Navigation

Canal (HNC). Generally, stages in the LAR force flow northeast through the Avoca

Island Cutoff into the GIWW and Bayou Penchant. Additional flow enters the GIWW

from the Verret Basin through Bayou Boeuf. Water travels eastward along the GIWW

and through the Penchant basin. A portion of this water leaves the project area through

the Penchant basin along natural and man-made channels. The remaining flow continues

east along the GIWW. At Houma, the GIWW intersects the HNC. At this point, the

majority of flow travels down the HNC to the Gulf of Mexico. The remaining flow

continues east along the GIWW. A small amount of water enters the marshes of the

Grand Bayou basin through two channels, Company Canal and Bayou L’Eau Blue.

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Finally, the flow exits the project area along the GIWW through the Bayou Lafourche

ridge.

Fresh water flow introduction to the Boudreaux basin is limited. The basin is

hydraulically isolated by the Bayou Grand Caillou ridge on the west and the Bayou Petit

Caillou ridge on the east. Bayou Chauvin and forced drainage areas supply fresh water to

the northern Boudreaux basin. Bayou Dulac provides a natural connection to Bayou

Grand Caillou. Boudreaux Canal and Robinson Canal provide man made connections to

Bayou Petit Caillou. Any remaining fresh water inflow is provided through local

drainage.

The Grand Bayou basin is hydraulically isolated by the Bayou Pointe au Chien ridge to

the west and Bayou Lafourche ridge and back levees to the east as well as LA highway

24 to the north along the Bayou Blue ridge. The major sources of fresh water in this

basin include the connection of St. Louis Canal and Bayou L’eau Blue to the GIWW as

well as forced drainage areas and local drainage.

Bayou Boeuf is currently the outlet for the Verret basin. Backwater effects can slow

drainage through the Bayou Black ridge, thus affecting the duration of high water levels

in the Lake Verret area.

Water levels throughout the project area are influenced by tides in the Gulf of Mexico.

Water advances and retreats in channels and marshes with the tidal cycle. Water levels

can also vary with seasonal wind direction. In the fall and winter, southern winds push

water into the marshes. During other parts of the year, northern winds push water out of

the marshes.

4.2.2.2 Sedimentation and Erosion

4.2.2.2.1 Historic and Existing Conditions

Historically, the Atchafalaya River and Bayou Lafourche were sources of sediment to the

project area. Sediment would be delivered throughout the project area during annual

floods through systems of distributary channels and through overland flow. Since that

time, the altered hydrology due to the construction of the Atchafalaya Basin Floodway;

GIWW; Atchafalaya River; Bayous Chene, Boeuf, and Black Navigation Channel;

Houma Navigation Canal; and Houma area levees and pump systems, drainage canals,

and access canals have altered sediment distribution within the project area.

Today, suspended sediments in the Atchafalaya River, Bayou Lafourche and Bayou

Boeuf water are the sources of new sediment to the project area. Bank line erosion is a

source of sediment from within the project area. Suspended sediments are readily

distributed throughout the Penchant basin. The only pathway available for suspended

sediments to reach the Boudreaux basin is Bayou Dulac, near the southern end of the

basin. The small amounts of sediments that enter the basin are not well distributed.

Grand Bayou marshes receive small amounts of suspended sediment during spring

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flooding on the Atchafalaya River, when the flows in the GIWW are highest. These

sediments are limited due to the distance from the Atchafalaya River and the small size of

the connection to the GIWW. Much of the sediment that enters the Grand Bayou basin is

efficiently flushed from the basin through Cutoff Canal.

Periodic dredging of navigation channels occurs today. The source of the sediments is

bank line erosion. This erosion is the result of wave wash from both natural and

manmade sources.

4.2.3 Water Quality and Salinity

This resource is institutionally significant because of the National Environmental Policy

Act of 1969; the Clean Water Act; the Coastal Zone Management Act; and the Estuary

Protection Act. This resource is technically significant because the water quality

supports most physical, chemical, geological, and biological processes throughout the

entire estuarine system. This resource is publicly significant because the public demands

clean water and healthy wildlife and fishery species for recreational and commercial use.

4.2.3.1 Historic and Existing Conditions

The Louisiana Department of Environmental Quality (LDEQ) is responsible for meeting

the state’s obligation to comply with Sections 303(d) and 305(b) of the Clean Water Act.

Sections 303(d) and 305(b) require states to assess the water quality of water bodies with

respect to their ability to support recreational and fish and wildlife propagation activities

(“designated uses”) and it requires states to provide a list of impaired water bodies (the

“303(d) list”). Designated uses for Louisiana water bodies and associated water quality

criteria are set by the State (Louisiana Administrative Code (LAC) 33:IX.1101). The

most common designated uses within the study area include primary contact recreation,

secondary contact recreation, fish and wildlife propagation, oyster propagation, and

drinking water supply. Primary contact recreation is defined as any recreational activity

that involves or requires prolonged body contact with the water, such as swimming, water

skiing, tubing, snorkeling, and skin-diving. Secondary contact recreation is defined as

any recreational activity that may involve incidental or accidental body contact with the

water and during which the probability of ingesting appreciable quantities of water is

minimal, such as fishing, wading, and recreational boating. Fish and wildlife propagation

is defined as the use of water for preservation and reproduction of aquatic biota such as

indigenous species of fish and invertebrates, as well as reptiles, amphibians, and other

wildlife associated with the aquatic environment. This also includes the maintenance of

water quality at a level that prevents contamination of aquatic biota consumed by

humans. Oyster propagation is the use of water to sufficiently maintain biological

systems that support economically important species of oysters, clams, mussels, or other

mollusks so that their productivity is preserved and the health of human consumers of

these species is protected.

Table 4.1 outlines the 303(d) list of impaired water bodies in the project area (LDEQ

2008). Suspected sources of impairment for fecal coliform in the project area are

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generally sewage discharges or animal waste contamination. Suspected sources for

dissolved oxygen impairment vary widely from location to location.

Table 4.1. Impaired Water Bodies Within the Project Area.

Water Body Category not Meeting

Designated Use*

Cause of Impairment

Atchafalaya River – from

GIWW to Atchafalaya Bay

FWP Dissolved Oxygen

Bayou Black - from GIWW to

Houma

PCR, FWP Fecal Coliform

Lake Palourde FWP Turbidity (sediment

resuspension)

Bayou Penchant – from Bayou

Chene to Lake Penchant

FWP, ONR Total Suspended Solids /

Turbidity (natural sources)

GIWW - from Houma to

LaRose

PCR, FWP Fecal Coliform

Bayou Grand Caillou - from

Houma to Bayou Pelton

PCR, FWP Fecal Coliform

Bayou Grand Caillou - from

Bayou Pelton to HNC

FWP, OYS Dissolved Oxygen

HNC - from Houma to Bayou

Pelton

FWP Dissolved Oxygen

Bayou Terrebonne – from

Houma to Company Canal

PCR Fecal Coliform

FWP Dissolved Oxygen

Bayou Terrebonne – from

Humble Canal to Lake Barre

OYS Fecal Coliform

Bayou Petite Caillou – from

Boudreaux Canal to HNC

OYS Fecal Coliform

* PCR = Primary Contact Recreation

FWP = Fish and Wildlife Propagation

OYS = Oyster Propagation

ONR = Outstanding Natural Resources

The Louisiana Department of Health and Hospitals (LDHH) coordinates with LDEQ, the

Louisiana Department of Wildlife and Fisheries, and the Louisiana Department of

Agriculture and Forestry to issue water body advisories aimed at protecting the public’s

health. These include fish and shellfish consumption advisories and swimming

advisories. Fish and shellfish consumption advisories employ a risk-based method to

advise the public to limit or avoid the intake of certain species of fish and shellfish that

have unsafe contaminant levels in their tissues. Swimming advisories may be issued for

a water body due to fecal coliform or other types of contamination. No water bodies

within the project area currently have fish consumption or swimming advisories in place.

However, Gulf of Mexico waters off of all coastal parishes are under a fish consumption

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advisory related to mercury contamination. This information comes from the latest

publications on LDEQ’s websites in November 2009.

Salinity levels throughout the project area are influenced by tides in the Gulf of Mexico.

Saline waters advance and retreat in channels and marshes with the tidal cycle. As the

land subsides and the marshes disappear, the limit of the saline water advances further

north. Salinity levels can also vary with seasonal wind direction. In the fall and winter,

southern winds push saline water into the marshes. During other parts of the year,

northern winds push water out of the marshes, reducing salinity levels.

Man made canals within the study area provide efficient conduits for salinity to enter

portions of the study area. These canals include the Houma Navigation Canal, Cutoff

Canal, Robinson Canal, unnamed oil and gas exploration canals, and pipeline canals.

4.2.4 Air Quality

This resource is institutionally significant because of the Clean Air Act of 1963, as

amended (CAA), and the Louisiana Environmental Quality Act of 1983, as amended

(LEQA). Air quality is technically significant because of the status of regional ambient

air quality in relation to the National Ambient Air Quality Standards (NAAQS). It is

publicly significant because of the desire for clean air expressed by virtually all citizens.

4.2.4.1 Historic and Existing Conditions

Based upon a review of an ambient air quality three-year trend analysis (2005-2007)

conducted by the Louisiana Department of Environmental Quality – Air Quality

Assessment Division (LDEQ-AQD), there were no violations of state air quality

standards at the monitoring stations nearest the project area (Houma and Thibodaux;

LDEQ 2008). The LDEQ-AQD also indicated that there are no non-attainment areas or

deviations from National Ambient Air Quality Standards in the general vicinity. These

findings indicate that the air quality in the project area is generally good. Terrebonne,

Lafourche, St. Martin, St. Mary, and Assumption Parishes are currently classified as

attainment areas for all NAAQS (LDEQ 2008). This classification is the result of areawide air quality modeling studies.

4.2.5 Noise

Noise is institutionally significant because of the Noise Control Act of 1972 and the

Occupational Safety and Health Standards (29 CFR, part 1910) regarding protection

against the effects of noise exposure. Noise is technically significant because noise can

negatively affect the physiological or psychological well-being of an individual (Kryter

1994) ranging from annoyance to adverse physiological responses, including permanent

or temporary loss of hearing, and other types of disturbance to humans and animals,

including disruption of colonial nesting birds. Noise is publicly significant because of the

public’s concern for the potential annoyance and adverse effects of noise on wildlife and

humans.

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Noise levels are computed over a 24-hour period and adjusted for nighttime annoyances

to produce the day-night average sound level (DNL). DNL is the community noise

metric recommended by the USEPA and has been adopted by most Federal agencies

(USEPA 1974). A DNL of 65 weighted decibels (dBA) is the level most commonly used

for noise planning purposes and represents a compromise between community impact

and the need for activities like construction. Areas exposed to a DNL above 65 dBA are

generally not considered suitable for residential use. A DNL of 55 dBA was identified by

the USEPA as a level below which there is no adverse impact (USEPA 1974).

4.2.5.1 Historic and Existing Conditions

Noise, or unwanted sound, may be objectionable in terms of the health or nuisance effects

it may have upon humans and human resources, as well as upon animals and ecological

resources. The Noise Control Act of 1972 declares the policy of the United States to

promote an environment for all Americans free from noise that jeopardizes their health or

welfare. It is the purpose of the Act to establish a means for effective coordination of

Federal activities in noise control and to provide information to the public regarding the

noise emissions.

Residential and commercial concentrations in the project area are subjected to noise

typically associated with human activities and habitations, such as car and truck traffic,

operation of commercial and recreational boats, water vessels, air boats, and other

recreational vehicles; operation of machinery and motors; and human residential-related

noise (air conditioners, lawn mowers, etc.). Much of the study area is a remote and

uninhabited marsh. The noise from distant urban areas surrounding the uninhabited

portions of the study area has little, if any, impact on the ambient sound setting of the

area.

4.2.6 Vegetation Resources

Coastal vegetation resources are institutionally significant because of the Coastal Barrier

Resources Act of 1982; Coastal Zone Management Act of 1972; Emergency Wetlands

Resources Act of 1986; Estuary Protection Act of 1968; Fish and Wildlife Conservation

Act of 1980; Fish and Wildlife Coordination Act of 1958, as amended; Migratory Bird

Conservation Act; Migratory Bird Treaty Act; Endangered Species Act of 1973;

Magnuson Fishery Conservation and Management Act 1990; National Environmental

Policy Act of 1969; the North American Wetlands Conservation Act; the Water

Resources Development Acts of 1976, 1986, 1990, and 1992; and Executive Order 13186

Migratory Bird Habitat Protection. Coastal vegetation resources are technically

significant because they are a critical element of the coastal habitats. In addition, coastal

vegetation resources serve as the basis of productivity, contribute to ecosystem diversity,

provide various habitat types for fish and wildlife, and are an indicator of the health of

coastal habitats. Coastal vegetation resources are publicly significant because of the high

priority that the public places on their aesthetic, recreational, and commercial value.

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Louisiana’s coastal wetlands comprise a variety of environments formed by spatially and

temporally varying conditions that continually influence and change the vegetative

landscape. The environmental factors and their innumerable combinations that regulate

the occurrence and distribution of plant species and associations include, but are not

limited to, soil and water salinity, soil type, elevation, hydrology and flooding regime,

tidal influence, and climate. Competition, especially from invasive species, herbivory

pressure, and man-made disturbance, such as burning or hydrologic modification, are

other forces that can impact vegetative species.

Each plant species adapts to a definite range of environmental conditions, and those

species that are adapted to similar conditions form communities or associations that are

best able to grow and successfully compete for a particular site. Wherever the prevailing

environmental conditions are similar, analogous communities with comparable species

composition and dominance tend to occur. When environmental conditions change,

succession can occur where plant species or whole communities are replaced by others

more suited to the new conditions (O’Neil 1949; Chabreck 1972a).

In habitats with restricted variation in conditions, such as those with extreme salinity,

species diversity is reduced. Since the source of salinity in coastal Louisiana is the Gulf

of Mexico, salinity levels exist along a gradient, which declines as the saltwater moves

inland. A zonation of plant species that differ in salinity tolerance exists along that

gradient, with the species diversity of those zones increasing from salt to fresh

environments (see Table 4.2).

Table 4.2. Salinity Ranges for the Four Coastal Wetland Types.

Wetland Type Range (ppt) Mean (ppt) Typical Range (ppt)

Fresh 0.1 – 6.7 <3.0 0 – 3

Intermediate 0.4 – 9.9 3.3 2 – 5

Brackish 0.4 – 28.1 8.0 4 – 15

Saline 0.6 – 51.9 16.0 12+

(Source: Chabreck 1972b; Louisiana Coastal Wetlands Conservation and Restoration

Task Force and the Wetlands Conservation and Restoration Authority 1999)

There are two basic types of fresh marsh in the area, flotant emergent and attached

emergent. The flotant marsh is not attached to the underlying soil although the marsh

plants form a dense mat that appears to be solid. The flotant marshes contain primarily

maiden-cane, coastal arrowhead, and Baldwin's spikerush (Sasser et al. 1994). Sasser et

al. (1994) estimate that about 70 percent of the marshes in the Barataria-Terrebonne

estuary are flotant. The attached emergent fresh marsh is attached to the underlying soil

and also contains predominantly maidencane and coastal arrowhead, along with

spikerush, alligatorweed, common reed, coastal water-hyssop, penny-wort, and

saltmeadow cordgrass (Bahr et al. 1983; Gosselink 1984; Conner and Day 1987).

Intermediate marsh habitat lies between fresh marsh and brackish marsh and the species

of vegetation do not generally differ significantly from those found in fresh marsh, but

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different species may be dominant. According to Gosselink (1984) saltmeadow

cordgrass is the dominant species in intermediate marsh, with coastal arrowhead,

common reed, coastal water-hyssop, seashore paspalum, spikerush, and Olney's bulrush

also common.

The dominant brackish marsh plant is saltmeadow cordgrass, comprising about one-half

of the plants (Gosselink 1984: Conner and Day 1987). By comparison, this species

comprises about one-third of the plants in intermediate marsh (Gosselink 1984). Other

important species include seashore saltgrass, camphorweed, and coastal water-hyssop

(Conner and Day 1987).

Salt marsh is dominated by saltmarsh cordgrass, comprising some 62 percent of the

plants. Other important species are needlegrass rush, seashore saltgrass, and saltmeadow

cordgrass (Conner and Day 1987). Saltmeadow cordgrass is prevalent only at slightly

higher elevations along distributary ridges.

Submerged and floating-leafed vegetation are most common in waterbodies associated

with forested wetlands and fresh and intermediate marshes. Submerged aquatic

vegetation consists mainly of coontail, hydrilla, elodea, pondweeds, water stargrass, wild

celery, fanwort, and Eurasian milfoil. The floating leafed species include American

lotus, water lettuce, water hyacinth, water spangles, and duckweeds. In brackish

marshes, SAV is most often found in protected areas away from excessive wave action.

Wigeon grass, southern naiad, and Eurasian milfoil are the most common species in

brackish water.

In order to determine existing and likely future conditions in the project area and

facilitate determination of project impacts on area marshes, CEMVN contracted USGS to

conduct habitat and land loss analyses on the project area based on mapping of the area

from 1956 to 2008. The project was broken up into 65 polygons, with habitat

classification and land loss analysis conducted on each. The results of these analyses are

presented in Table 4.3 and Figures 4.4 through 4.6. In order to determine the rate of land

loss or land gain within each of the polygons, data from 1985 to 2008 were utilized. The

overall rate of land loss in the project area was determined to be 2,597 acres/year

(approximately 0.3 percent per year). However, as can be seen in Figure 4.6, there is

considerable variation from polygon to polygon in the rate of land loss or land gain. In

general, the areas with the highest rates of land loss are the intermediate, brackish, and

saline marshes in the southern and eastern sections of the project area. The swamp and

fresh marsh habitats generally are exhibiting lower rates of land loss and in some cases

land gain.

In order to document the quality of the habitat in the project area in terms of its suitability

for fish and wildlife use, the Wetland Value Assessment (WVA; CWPPRA 2007)

methodology was utilized. WVA analysis was performed to determine existing

conditions, future without project conditions and impacts of Alternatives. A description

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of the WVA analysis can be found in Appendix M. A summary of the results of the

WVA analysis can be found in Table 5.3.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 4.3. Habitat Types (in acres) in the Project Area from 1956 to 2008 (based on Barras et al. 2008 and Barras 2009).1 Incomplete data in study area for 1956 and 1978 imagery. 1985 to 2008 imagery was used in calculation of land loss trend lines based on USGS 0recommendation for improving accuracy of projections.2 Variations in calculated land area from year to year occur due to actual land loss and land gain, major storm events, differing tides/water elevations

on the dates imagery was captured, random variation, etc. Trend lines over longer periods of time provide a more accurate picture of actual land losstrends than comparing individual years (see Figure 3.1).

5

Habitat

Category 1956 1978 1985 1988 1990 1998 1999 2000 2001 2002 2004 2005 2006 2008

Swamp --- 39,595 --- 96,073 --- --- --- 93,156 64,765 --- 64,765 64,759 65,101 ---

Fresh Marsh --- 168,652 --- 204,784 --- --- --- 198,516 240,241 --- 244,023 240,171 213,032 ---

Intermediate

Marsh --- 66,975 --- 54,532 --- --- --- 46,301 51,493 --- 49,210 49,028 62,591 ---

Brackish Marsh --- 100,424 --- 101,642 --- --- --- 79,285 81,996 --- 79,562 78,120 65,148 ---

Saline Marsh --- 81,905 --- 87,076 --- --- --- 64,406 68,246 --- 67,294 64,805 86,795 ---

Total Land Area 619,822 517,010 613,936 649,064 627,223 582,939 602,428 579,684 597,316 599,453 595,262 585,852 583,483 576,400

Total Water

Area 119,254 223,044 285,211 250,083 271,924 316,208 296,719 319,463 301,831 299,694 303,885 313,295 315,664 322,747

Total Area1 739,076 740,054 899,147 899,147 899,147 899,147 899,147 899,147 899,147 899,147 899,147 899,147 899,147 899,147

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.4. Project Area Polygons Used in Land Gain/Loss Analysis.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.5. Habitat Classifications in the Project Area from 1956 to 2000 (based on Barras et al. 2008).

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.6. Land Gain/Loss Rates in the Project Area – percent per year based on 1985 to 2008 rates and 1985 acreage (based on Barras et al. 2008 and 10

Barras 2009). Negative numbers indicate land loss.

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4.2.6.1 Invasive Species - Vegetation

Table 4.4 summarizes nonindigenous aquatic plant species that have been found in the

Atchafalaya and Terrebonne drainage basins (USGS 2009; LDWF 2005). In coastal

Louisiana, water hyacinth, alligator weed and hydrilla are well-known invasive plants.

More recently, common salvinia, giant salvinia, and variable-leaf milfoil also have

become invasive, displacing native aquatic species and degrading water quality and

habitat quality (USACE 2008).

Table 4.4. Nonindigenous Aquatic Plant Species in the Atchafalaya and Terrebonne Basins (USGS

2009; LDWF 2005).

Common Name Scientific Name Habitat

Alligatorweed Alternanthera philoxeroides Freshwater

Wild taro Colocasia esculenta Freshwater

Water-lettuce Pistia stratiotes Freshwater

Parrot feather Myriophyllum aquaticum Freshwater

Eurasian water-milfoil Myriophyllum spicatum Freshwater-Brackish

Brazilian waterweed Egeria densa Freshwater

Hydrilla Hydrilla verticillata Freshwater

Dotted duckweed Landoltia (Spirodela) punctata Freshwater

Uruguay waterprimrose Ludwigia grandiflora Freshwater

Peruvian watergrass Luziola peruviana Freshwater

Torpedo grass Panicum repens Freshwater

Water-hyacinth Eichhornia crassipes Freshwater

Common salvinia Salvinia minima Freshwater

Giant salvinia Salvinia molesta Freshwater

4.2.7 Wildlife and Habitat

This resource is institutionally significant because of the Fish and Wildlife Conservation

Act of 1980, the Fish and Wildlife Coordination Act of 1958, as amended, the Migratory

Bird Conservation Act, the Migratory Bird Treaty Act, the Endangered Species Act of

1973 (ESA), and Executive Order 13186 Migratory Bird Habitat Protection. Wildlife

resources are technically significant because they are a critical element of the various

coastal habitats, they are an indicator of the health of various coastal habitats, and many

wildlife species are important commercial resources. Wildlife resources are publicly

significant because of the high priority that the public places on their aesthetic,

recreational, and commercial value.

4.2.7.1 Historic and Existing Conditions

Coastal Louisiana's wetlands support millions of neotropical and other migratory avian

species such as rails, gallinules, shorebirds, wading birds, and numerous songbirds, as

well as many different furbearers, rabbits, deer, and alligators. Louisiana coastal

wetlands provide neotropical migratory birds an essential stopover habitat on their annual

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migration route. The coastal wetlands in the study area provide important and essential

fish and wildlife habitats used for shelter, nesting, feeding, roosting, cover, nursery, and

other life requirements.

Over 200 species of birds including 35 species of waterfowl have been reported from the

Barataria-Terrebonne estuarine system (Condrey et al. 1995; Mitchell 1991). In general,

wildlife species diversity is greatest in the swamp and decreases moving into salt marsh.

In swamps, 25 mammalian, 32 reptilian, and 18 amphibian species occur, but only 8

species of mammals, 4 species of reptiles (not including sea turtles), and no amphibians

are found in salt marsh (Gosselink 1984). This trend is reversed for colonial nesting

water birds (i.e. wading birds and seabirds) that are found in greater variety in salt

marshes.

Songbirds such as the northern parula, prothonotary warbler, mockingbird, and Carolina

chickadee nest and feed in forested wetlands and scrub-shrub areas. Numerous other bird

species, including common flicker, white-eyed vireo, loggerhead shrike, redheaded

woodpecker, and American woodcock also use forested areas.

Alligators are abundant in fresh to brackish bayous and lakes (Joanen and McNease

1972; Platt et al. 1989). Alligators consume a wide variety of food items including

insects, crawfish, crab, birds, fish, muskrat, nutria, turtles, shrimp, snails, and turtles

(Chabreck 1971; Platt et al. 1990). They build nests in marshes and along levees,

particularly wax myrtle thickets in fresh marshes (Gosselink 1984) where salinities are

less than 10 ppt. Although listed as an endangered species in 1967, the alligator was

deemed fully recovered and removed from the endangered species list in 1987. However,

the Fish and Wildlife Service continues to protect the alligator under the classification of

“threatened due to similarity of appearance” due to its similarity to other members of the

crocodile family that remain endangered species. The Fish and Wildlife Service

regulates the harvest of alligators and populations are considered secure.

Waterfowl are mostly winter residents that migrate north each spring and summer and

populations are highly variable. Wood duck, mottled duck, and black-bellied whistlingduck are the only species which regularly breed in the area. In salt and brackish marsh,

gadwall, American coot, and blue-winged teal are the most abundant species. In fresh

marsh, American coot, blue-winged teal, and mallard are the most abundant species

(Sasser et al. 1982). Puddle ducks (e.g. gadwall and blue-winged teal) prefer marshes

with small shallow ponds less than 0.5 meters deep. Widgeon-grass is the preferred food

of puddle ducks in brackish marshes, while pondweed, naiad, and duckweed are the

preferred items in fresh marsh. Diving ducks (e.g. Scaup spp.) prefer deeper water and

dive to depths of over 10 meters to feed on invertebrates (Gosselink 1984).

Wading birds (e.g. herons and egrets) are common year-round residents to the marshes

and swamps. These birds are mostly carnivorous. They catch frogs, small fish, snakes,

crawfish, worms, and insects in shallow ponds and along bayous for food. They appear

to prefer brackish marshes for feeding (Gosselink 1984), but colonies tend to be located

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in wooded and shrub swamps that are isolated and flooded during the nesting season

(March-August; Mitchell 1991). Seabirds (e.g. gulls and terns) nest on shell, sand, or

bare soil primarily on barrier islands and bay islands that have these soil characteristics

(Mitchell 1991).

There are 14 known nesting colonies of wading or seabirds within or in close proximity

to the study area (Martin and Lester 1990), but many are not active. Three large colonies

are located north of the GIWW in subarea A1 and consist mostly of great egret, little blue

heron, and glossy and white faced ibis. A medium colony of mostly great egret occurs

east of Lake Theriot in subarea A4. A small colony predominantly composed of snowy

egret is located in subarea C2. Small colonies of Forster's tern occur south of Lake

Felicity near subarea E3.

Muskrat (probably a native species) is a furbearer found mostly in brackish marshes with

Olney bulrush. Reports of muskrat damage in brackish marsh are common with high

populations of this rodent. There seems to be a 10- to 14-year cycle of marsh growth and

collapse associated with muskrat populations (O'Neil 1949). Recovery of the vegetation

following an eat-out is poor (Gosselink and Sasser 1995). Muskrat eat one-third of their

weight per day (about 0.3 kg/day; O'Neil 1949) or less than 1 percent of plant production.

It is actually their nest building and digging that cause most of the marsh deterioration.

Nutria (introduced from South America in 1938 and about 6 times larger than muskrat)

has become the predominant furbearer in fresh marsh (especially flotant) and swamp

(Gosselink and Sasser 1995). Linscombe and Kinler (1994) found that vegetation

damage by nutria can also be serious, particularly in fresh marsh. Recovery appears to

take >1 year.

White-tailed deer are most prevalent in BLH and swamp habitat with density declining

with increasing marsh salinity. Deer prefer areas above standing water, such as natural

levees and dredged material disposal areas and prefer newly-grown succulent vegetation

(Self 1975) including alligator weed, eastern false-willow, black willow, and common

reed. They are common, however, in fresh and intermediate marshes provided there are

suitable cover and browse plants.

Table 4.5 displays the functions of interest, status, trends, and projections through the

year 2050 of avifauna, furbearers, game mammals, and reptiles found in mapping units in

the project area as reported in the Coast 2050 report (LCWCRTF and WCRA 1998).

Future projections of wildlife abundance in the Coast 2050 report were based almost

exclusively on the projected conversion of marsh habitat to open water and subsidence of

forested habitats and the anticipated impacts.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 4.5. Functions of Interest, Status, Trends, and Projections through 2050 of Avifauna, Furbearers, Game Mammals, and Reptiles in the Project Area(LCWCRTF and WCRA 1998).Type: OW = Open Water; FM = Fresh Marsh; IM = Intermediate Marsh; BM = Brackish Marsh; FS = Fresh Swamp; HF = Hardwood Forest; AU = Agriculture / Upland

Function: Ne = Nesting; St = Stopover Habitat; W = Wintering; Mu = Multiple UseStatus: NH = Not Historically Present; NL = No Longer Present; Lo = Low Numbers; Mo = Moderate Numbers; Hi = High Numbers

Trend (since 1985)/Projection (through 2050): Sy = Steady; D = Decrease; I = Increase; U = Unknown

Mapping

Unit Type

%

of

Unit

Avifauna

Brown Pelican Bald Eagle Seabirds Wading Birds Shorebirds Dabbling Ducks Diving Ducks Geese Raptors

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Penchant OW 19 NH NH Mu Mo Sy Sy NH NH W Hi Sy D W Hi Sy D W Mo I D NH

FM 67 NH NE Mo I I Mu Lo Sy D Mu Hi I Sy Mu Hi Sy D W Hi Sy D W Hi Sy D W Mo I D Mu Lo Sy D

HF 9 NH NH NH NH NH W Mo Sy Sy NH NH Mu Hi I D

Mechant /de Cade

OW 46 W Hi I I NH Mu Mo Sy Sy NH NH W Mo Sy Sy W Mo Sy Sy NH NH

IM 14 NH NH Mu Mo Sy D Mu Hi I Sy Mu Hi Sy D W Mo Sy Sy W Mo Sy Sy NH Mu Lo Sy D

BM 29 NH NH Mu Mo Sy D Mu Hi I Sy Mu Hi Sy D W Mo Sy Sy W Mo Sy Sy NH Mu Lo Sy D

FS 1 NH Ne Lo Sy Sy NH NH NH Ne Lo Sy Sy W Mo Sy Sy NH NH

NorthHoumaShipCanalWetlands

OW 16 NH NH St Lo Sy Sy NH NH W Lo Sy D W Lo Sy D NH NH

IM 14 NH NH Mu Lo Sy Sy Mu Mo I Sy Mu Mo Sy Sy W Lo Sy D W Lo Sy D NH Mu Lo Sy Sy

FS 28 NH NH NH Ne Mo I Sy NH W Lo Sy D W Lo Sy D NH Mu Mo I Sy

HF 26 NH NH NH NH NH Mu Lo Sy D NH NH Mu Hi I D

AU 11 NH NH NH St Lo I Sy St Lo Sy Sy NH NH NH Mu Mo Sy Sy

Boudreaux OW 48 W Lo I I NH Mu Mo Sy Sy NH NH W Lo D D W Lo Sy D NH NH

IM 13 NH NH Mu Mo Sy D Mu Hi Sy D Mu Hi Sy D W Lo D D W Lo Sy D NH Mu Lo Sy D

BM 20 NH NH Mu Mo Sy D Mu Hi Sy D Mu Hi Sy D W Lo D D W Lo Sy D NH Mu Lo Sy D

HF 9 NH Ne Lo Sy Sy NH NH NH Mu Lo D D W Lo Sy D NH Mu Hi Sy D

St. LouisCanal

OW NH NH Mu Mo Sy Sy NH NH W Lo Sy Sy W Lo Sy Sy NH NH

FS NH Ne Lo Sy Sy NH Ne Hi I D NH Mu Lo Sy Sy W Lo Sy Sy NH Mu Mo I D

IM NH NH Mu Lo Sy Sy Mu Hi I D Mu Hi Sy D W Lo Sy Sy W Lo Sy Sy NH Mu Lo Sy D

BM NH NH Mu M Sy Sy Mu Hi I D Mu Hi Sy D W Lo Sy Sy W Lo Sy Sy NH Mu Lo Sy D

HF NH NH NH NH NH Mu Lo Sy Sy NH NH Mu Hi Sy D

North

BullyCamp

OW 50 W Lo I I NH Mu Mo Sy Sy NH NH W Lo Sy D W Lo Sy D NH

FM 5 NH NH Mu Mo Sy D Mu Hi Sy D Mu Hi Sy D W Lo Sy D W Lo Sy D NH Mu Lo Sy D

IM 6 NH NH Mu Mo Sy D Mu Hi Sy D Mu Hi Sy D W Lo Sy D W Lo Sy D NH Mu Lo Sy D

BM 30 NH NH Mu Mo Sy D Mu Hi Sy D Mu Hi Sy D W Lo Sy D W Lo Sy D NH Mu Lo Sy D

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Mapping

Unit Type

%

of

Unit

Avifauna (cont.) Furbearers Game Mammals Reptiles

Rails, Coots, and

Gallinules

Nutria Muskrat Mink, Otter, and

Raccoon

Rabbits Squirrels Deer American

Alligator

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Function

Status

Trend

Projection

Penchant OW 19 W Hi Sy Sy Mu Hi Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy NH NH NH Mu Hi I I

FM 67 Mu Hi Sy Sy Mu Hi Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy Mu Lo Sy Sy NH Mu Lo Sy Sy Mu Hi I I

HF 9 NH Mu Hi Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy Mu Mo I I

Mechant /de Cade

OW 46 W Mo Sy Sy Mu Mo D D Mu Mo D D Mu Mo D D NH NH NH Mu Lo Sy D

IM 14 Mu Mo Sy Sy Mu Mo D D Mu Mo D D Mu Mo D D Mu Lo Sy Sy NH Mu Lo Sy Sy Mu Hi I D

BM 29 Mu Mo Sy Sy Mu Mo D D Mu Mo D D Mu Mo D D Mu Lo Sy Sy NH Mu Lo Sy Sy Mu Mo I D

FS 1 NH NH NH NH Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy NH

North

HoumaShipCanalWetlands

OW 16 W Lo Sy D NH NH NH NH NH NH Mu Mo Sy Sy

IM 14 W Lo Sy D Mu Lo D Sy Mu Lo D Sy Mu Lo D Sy Mu Lo Sy D NH Mu Lo Sy D Mu Mo Sy Sy

FS 28 W Lo Sy D Mu Lo D Sy Mu Lo D Sy Mu Lo D Sy Mu Lo Sy D Mu Lo Sy D Mu Lo Sy D Mu Mo Sy Sy

HF 26 NH Mu Lo D Sy Mu Lo D Sy Mu Lo D Sy Mu Lo Sy D Mu Lo Sy D Mu Lo Sy D Mu Lo Sy Sy

AU 11 NH Mu Lo D Sy Mu Lo D Sy Mu Lo D Sy Mu Mo Sy D NH Mu Lo Sy D Mu Lo Sy Sy

Boudreaux OW 48 W Lo Sy D NH NH NH NH NH NH Mu Lo D D

IM 13 W Lo Sy D Mu Mo Sy D Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo Sy D NH Mu Lo Sy D Mu Mo I Sy

BM 20 W Lo Sy D Mu Lo Sy D Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo Sy D NH Mu Lo Sy D Mu Lo Sy D

HF 9 NH Mu Lo Sy D Mu Lo Sy Sy Mu Lo Sy Sy Mu Mo Sy D Mu Lo Sy D Mu Lo Sy D Mu Lo Sy Sy

St. LouisCanal

OW W Lo Sy Sy Mu Mo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy NH NH NH Mu Mo I Sy

FS NH Mu Mo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy NH Mu Lo Sy Sy Mu Mo I Sy

IM Mu Lo Sy Sy Mu Mo Sy Sy Mu Lo Sy Sy Mu Mo Sy Sy Mu Lo Sy Sy NH Mu Lo Sy Sy Mu Mo I Sy

BM Mu Lo Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy Mu Mo Sy Sy Mu Lo Sy Sy NH Mu Lo Sy Sy Mu Mo Sy Sy

HF NH Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy Mu Mo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy

North

BullyCamp

OW 50 W Lo Sy D Mu Lo D Sy Mu Lo D Sy Mu Lo D Sy NH NH NH Mu Lo D D

FM 5 W Lo Sy D Mu Mo D Sy Mu Lo D Sy Mu Lo D Sy Mu Lo Sy D NH Mu Lo Sy D Mu Lo D Sy

IM 6 W Lo Sy D Mu Mo D Sy Mu Lo D Sy Mu Lo D Sy Mu Lo Sy D NH Mu Lo Sy D Mu Lo D Sy

BM 30 W Lo Sy D Mu Lo D Sy Mu Lo D Sy Mu Lo D Sy Mu Lo Sy D NH Mu Lo Sy D Mu Lo D D

Type: OW = Open Water; FM = Fresh Marsh; IM = Intermediate Marsh; BM = Brackish Marsh; FS = Fresh Swamp; HF = Hardwood Forest; AU = Agriculture/Upland

Function: Ne = Nesting; St = Stopover Habitat; W = Wintering; Mu = Multiple UseStatus: NH = Not Historically Present; NL = No Longer Present; Lo = Low Numbers; Mo = Moderate Numbers; Hi = High NumbersTrend (since 1985)/Projection (through 2050): Sy = Steady; D = Decrease; I = Increase; U = Unknown

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The following information on the bald eagle was obtained by letter from the USFWS

dated 21 January 2009.

The project-area forested wetlands may provide nesting habitat for the bald eagle which

was officially removed from the List of Endangered and Threatened Species on August 8,

2007. Bald eagles nest in Louisiana from October through mid-May. Eagles typically

nest in mature trees (e.g., bald cypress, sycamore, willow, etc.) near fresh to intermediate

marshes or open water in the southeastern parishes. Areas with high numbers of nests

include the Lake Verret Basin south to Houma, the marsh/ridge complex south of Houma

to Bayou Vista, the north shore of Lake Pontchartrain, and the Lake Salvador area.

Eagles also winter, and infrequently nest, in mature pine trees near large lakes in central

and northern Louisiana. Major threats to this species include habitat alteration, human

disturbance, and environmental contaminants (i.e., organochlorine pesticides and lead).

Breeding bald eagles occupy “territories” that they will typically defend against intrusion

by other eagles, and that they likely return to each year. A territory may include one or

more alternate nests that are built and maintained by the eagles, but which may not be

used for nesting in a given year. Nest sites typically include at least one perch with a

clear view of the water or area where the eagles usually forage. Shoreline trees or snags

located near large waterbodies provide the visibility and accessibility needed to locate

aquatic prey. Bald eagles are vulnerable to disturbance during courtship, nest building,

egg laying, incubation, and brooding. Disturbance during this critical period may lead to

nest abandonment, cracked and chilled eggs, and exposure of small young to the

elements. Human activity near a nest late in the nesting cycle may also cause flightless

birds to jump from the nest tree, thus reducing their chance of survival. Although the

bald eagle has been removed from the List of Endangered and Threatened Species, it

continues to be protected under the Migratory Bird Treaty Act and the Bald and Golden

Eagle Protection Act.

4.2.7.2 Invasive Species – Wildlife

Table 4.6 summarizes nonindigenous aquatic animal species that have been found in the

Atchafalaya and Terrebonne drainage basins (USGS 2009; LDWF 2005).

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Table 4.6. Nonindigenous Aquatic Animal Species in the Atchafalaya and Terrebonne Basins.

Common Name Scientific Name Habitat

Grass carp Ctenopharyngodon idella Freshwater

Silver carp Hypophthalmichthys molitrix Freshwater

Bighead carp Hypophthalmichthys nobilis Freshwater

Black carp Mylopharyngodon piceus Freshwater

Nutria Myocastor coypus Freshwater

Asian clam Corbicula fluminea Freshwater

Zebra mussel Dreissena polymorpha Freshwater

Island applesnail Pomacea insularum Freshwater

Water flea Daphnia lumholtzi Freshwater

Australian spotted

jellyfish

Phyllorhiza punctata Marine

The following information on nutria is taken from LDWF (2005). Nutria are large,

herbivorous, aquatic mammals with large orange incisor teeth. They were introduced to

Louisiana from Argentina between 1900 and 1940 for fur farming. However, when some

fur farms failed, the nutria were released into the wild, and it was thought they would act

as a biocontrol for invasive water hyacinth (LeBlanc 1994).

Nutria are prolific breeders and they exacerbate coastal wetland loss by digging into soft

wetland soils and eating the roots of marsh vegetation. As the vegetation dies, the soft

soils become open water; these holes in the marsh are called “eat-outs” (USGS 2000).

Historically, fur demand meant that hunters and trappers kept populations somewhat in

check. After the price of nutria pelts plummeted in 1989, however, nutria populations

began to grow unbounded (USGS 2000).

The Coastwide Nutria Control Program, approved under CWPPRA in 2002, is designed

to remove approximately 400,000 nutria annually through an incentive payment program

designed to encourage nutria harvesting. A summary of numbers of nutria harvested in

Terrebonne, Lafourche, and St. Mary Parishes and herbivory damage estimates can be

found in Table 4.7. The vast majority of harvested nutria in Terrebonne Parish comes

from the Penchant basin marshes (Wiebe and Mouton 2009).

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 4.7. Nutria Harvested and Herbivory Damage Estimates by Parish in Seasons 1 through 7 of the Coastwide Nutria Control Program (Wiebe andMouton 2009).

Parish

Nutria Harvest and Herbivory Damage1 by Season

2002-2003 2003-2004 2004-2005 2005-2006 2006-2007 2007-2008 2008-2009

Harvest

Acres of

Damage Harvest

Acres of

Damage Harvest

Acres of

Damage Harvest

Acres of

Damage Harvest

Acres of

Damage Harvest

Acres of

Damage Harvest

Acres of

Damage

Lafourche 28,852 610 51,736 381 32,411 127 24,668 0 28,038 328 25,473 338 48,252 207

St. Mary 26,004 0 16,277 0 20,940 0 21,023 0 34,693 0 34,210 0 34,811 0

Terrebonne 92,831 12,521 72,846 7,679 81,135 4,541 57,756 7,340 99,433 5,915 78,934 3,768 74,587 3,162

Statewide

Total 308,160 21,888 332,596 16,906 297,535 14,260 168,843 14,868 375,683 9,244 308,212 6,471 334,038 5,422

1Acres of damage estimates represent damage along sampling transects only. Actual coastwide damage is approximately 3.75 times

larger than the area estimated by the survey.

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4.2.8 Aquatic Resources

4.2.8.1 Historic and Existing Conditions

4.2.8.1.1 Plankton Resources

This resource is institutionally significant because of the National Environmental Policy

Act of 1969, the Coastal Zone Management Act, and the Estuary Protection Act. This

resource is technically significant because plankton provide a major, direct food source

for animals in the water column and in the sediments; phytoplankton are responsible for

at least 40 percent of the photosynthesis occurring on the earth; plankton are important

for their role in nutrient cycling; plankton productivity is a major source of primary foodenergy for most estuarine systems throughout the world; and phytoplankton production is

the major source of autochthonous organic matter in most estuarine ecosystems (Day et

al. 1989). This resource is publicly significant because plankton form the lowest trophic

food level for many larger organisms important to commercial and recreational fishing.

In addition, there is a public health concern with noxious phytoplankton blooms (red and

brown tides) that produce toxins, and large-scale blooms can lead to hypoxic conditions,

which can result in fish kills.

Plankton communities serve an important role in the coastal waters of Louisiana. The

plankton are composed of three groups: bacterioplankton, phytoplankton, and

zooplankton (Knox 2001). Phytoplankton are the primary producers of the water column

and form the base of the estuarine food web. Zooplankton provide the trophic link

between the phytoplankton and the intermediate level consumers such as aquatic

invertebrates, larval fish, and smaller forage fish species (Day et al. 1989).

Microzooplankton appear to be important consumers of bacterioplankton, which are

typically enumerated primarily by culture and microscopic techniques. Culture

techniques are selective and invariably underestimate bacterial densities (Day et al.

1989).

"The Cooperative Gulf of Mexico Estuarine Inventory and Study, Louisiana," prepared

by the Louisiana Wildlife and Fisheries Commission in 1971, provides a summary of

plankton across the coastal estuaries of Louisiana in the late 1960s (Perret et al. 1971).

The dominant member of the zooplankton community throughout that study was the

copepod Acartia tonsa. The greatest concentrations of zooplankton were encountered in

Breton Sound. The lowest concentrations were encountered in Chandeleur Sound and

Lake Borgne east of the Mississippi River, Lakes Barre and Raccourci, and Terrebonne

and Timbalier Bays. Species diversity was greatest in the Breton Sound and Mississippi

River, East Bay, Garden Island Bay, and West Bay areas. Salinity appears to be the chief

controlling factor in the number of species present, while temperature, competition, and

predation control the number of individuals present. In addition, the abundance of certain

zooplankton may be indicative of good fishing areas.

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Phytoplankton are tiny, single-cell algae that drift with the motion of water. The

dominant groups are diatoms and dinoflagellates, and other important groups include

cryptophytes, chlorophytes (green algae), and chrysophytes (blue-green algae). In

Louisiana, eutrophic conditions can lead to noxious blooms of blue-green algae, often

dominated by single species of the genus Anabaena or Microcystis. Some species

produce toxins, and large scale blooms can lead to hypoxic conditions, which result in

fish kills in some cases. Such blooms tend to occur in fresh or oligohaline waters, up to

approximately 7 ppt salinity.

Phytoplankton in more saline environments can cause a different kind of bloom; Karenia

breve (formerly known as Gymnodinium breve), for example, is a dinoflagellate that has

been associated with red tides. Red tides are so named because the prolific growth stains

the water red. Toxins associated with red tides are capable of killing fish and shellfish.

Red tide populations well below the fish kill level pose a serious problem for public

health through shellfish contamination. Bivalve shellfish, especially oysters, clams, and

coquinas, can accumulate so much toxin that they become toxic to humans. Public health

concerns also emerge from studies that show that the presence of airborne toxins have an

impact on the human respiratory system (Mote Marine Lab website:

http://www.mote.org/index.php?src=news&refno=101&category=Newsroom).

Freshwater diversions have been utilized in some instances to attempt to reduce the

spread of red tides into coastal waters.

Zooplankton are faunal components of the plankton, including small crustaceans such as

copepods, ostracods, euphausiids, and amphipods; the jellyfishes and siphonophores;

worms, mollusks such as pteropods and heteropods; and the egg and larval stages of the

majority of benthic and nektonic animals (Rounsefell 1975). Zooplankton are weakly

swimming animals comprised of two broad categories: holoplankton, which are

planktonic species as adults, and meroplankton, which are organisms that occur in the

plankton during early life stages before becoming benthic or nektonic (most common are

immature forms of benthic invertebrates). Zooplankton serve as food for a variety of

estuarine consumers, but also are important for their role in nutrient cycling.

Although there are no clear general patterns of zooplankton abundance in estuaries, some

regional seasonal patterns have been described (Day et al. 1989). The zooplankton of

many estuarine water bodies are dominated by copepods of the genus Acartia. Cyclopoid

copepods and cladocerans are often abundant in low salinity waters of Louisiana (Hawes

and Perry 1978). Zoeae (a larval stage in some crustaceans) can make up a large

component of the meroplankton. Zooplankton in Louisiana waters are in some cases

dominated by zoeae of the mud crab Rithropanopeus harrisii.

While some zooplankton are euryhaline, others have distinct salinity tolerances.

Therefore, introduction of river water into estuarine systems can have dramatic shortterm impacts on plankton populations in adjacent coastal waters (Hawes and Perry 1978).

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4.2.8.1.2 Benthic Resources

These resources are institutionally significant because of the NEPA of 1969; the Coastal

Zone Management Act; and the Estuary Protection Act. These resources are technically

significant because the bottom of an estuary regulates or modifies most physical,

chemical, geological, and biological processes throughout the entire estuarine system via

what is called a “benthic effect.” Benthic animals are directly or indirectly involved in

most physical and chemical processes that occur in estuaries (Day et al. 1989). Benthic

resources are publicly significant because members of the epibenthic community (e.g.,

oysters, mussels, etc.) provide commercial and recreational fisheries as well as create

oyster reef habitats used by many marine and estuarine organisms.

Within a salt marsh, less than ten percent of the above-ground primary production of the

salt marsh is grazed by aerial consumers. Most plant biomass dies and decays and its

energy is processed through the detrital pathway. The major consumer groups of the

benthic habitat include bacteria and fungi, microalgae, meiofauna, and microfauna

(Mitsch and Gosselink 1993).

Benthic community structure is not static; it provides a residence for many sessile,

burrowing, crawling, and even swimming organisms. The benthic community is a

storehouse of organic matter and inorganic nutrients, as well as a site for many vital

chemical exchanges and physical interactions. Day et al. (1989) describe the functional

groups of estuarine benthic organisms. These groups include: macrobenthic (e.g.,

molluscs, polychaetes, decapods); microbenthic (e.g., protozoa); meiobenthic (e.g.,

nematodes, harpacticoid copepods, tubillaria), epibenthic; infauna (e.g., most bivalves);

interstitial fauna (e.g., beach meiofauna, tardigrades); suspension-feeders (e.g., bryozoa

and many bivalves); filter-feeders (e.g., porifera, tunicates, bivalves); nonselective

deposit feeders (e.g., gastropods); selective deposit feeders (e.g., nematodes, sand dollars,

fiddler crabs); raporial feeders and predators (e.g., star fish and gastropod drills); and

parasites and commensals (e.g., parasitic flatworms and copepods, pea crabs).

According to Mitsch and Gosselink (1993), the salt marsh is a major producer of detritus

for both the salt marsh system and the adjacent estuary. They point out that in some

cases exported marsh detritus is more important to the estuary than the phytoplanktonbased production in the estuary. Detritus export and the shelter found along marsh edges

make salt marshes important nursery areas for many commercially important fish and

shellfish. Salt marshes have been shown at times to be both sources and sinks of

nutrients, particularly nitrogen.

4.2.9 Fisheries

Fishery resources are institutionally significant because of the Fish and Wildlife

Coordination Act of 1958, as amended; the Endangered Species Act of 1973; the

Magnuson-Stevens Fishery Conservation and Management Act of 1976, as amended

(Magnuson-Stevens Act); the Magnuson-Stevens Act Reauthorization of 2006; the

Coastal Zone Management Act; and the Estuary Protection Act. Fishery resources are

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technically significant because they are a critical element of many valuable freshwater

and marine habitats, they are indicators of the health of various freshwater and marine

habitats, and many species are commercially important. Fishery resources are publicly

significant because of the high priority placed on their aesthetic, recreational, and

commercial value.

4.2.9.1 Historic and Existing Conditions

Louisiana’s coastal estuaries are the most productive in the Nation. Louisiana has

historically been an important contributor to the Nation’s domestic fish and shellfish

production, and one of the primary contributors to the Nation’s food supply for protein.

Most of the economically important saltwater fishes and crustaceans harvested in

Louisiana spawn offshore and then use estuarine areas for nursery habitat (Herke 1995).

Landings in 2008 for commercial fisheries in coastal Louisiana, estimated at 918 million

pounds, were the largest for any state in the contiguous U. S. and second only to Alaska

(NMFS 2009). These landings represent over ten percent of the total landings in the

U.S., with a value of approximately $274.9 million. Total fish and shellfish landings for

ports in the vicinity of the project area (Dulac-Chauvin, Golden Meadow-Leeville, and

Morgan City-Berwick) were 58 million pounds in 2008 with a dockside value of $77

million (NMFS Fisheries Statistics Division 2009 – personal communication).

In a letter dated 17 February 2009, the NMFS indicated fishery resources in the project

area include aquatic and tidally influenced wetland habitats that are designated as

essential fish habitat (EFH) for postlarval and juvenile life stages of brown shrimp and

white shrimp, red drum, and gulf stone crab (see Section 4.2.10, Essential Fish Habitat)

managed by the Gulf of Mexico Fishery Management Council (GMFMC). In addition,

water bodies and wetlands in the study area provide nursery and foraging habitats

supportive of a variety of economically important marine fishery species, such as striped

mullet, Atlantic croaker, gulf menhaden, spotted seatrout, sand seatrout, southern

flounder, black drum, and blue crab. Some of these species also serve as prey for other

fish species managed under the Magnuson-Stevens Fishery Conservation and

Management Act by the GMFMC (e.g., mackerels, snappers, and groupers) and highly

migratory species managed by NMFS (e.g., billfishes and sharks).

4.2.9.1.1 Finfish

By far the top position in landings of finfish, by weight, for the State of Louisiana is held

by Gulf menhaden, which contributed more than 97 percent of the total finfish landings

in 2008 (NMFS Fisheries Statistics Division 2009 – personal communication). Gulf

menhaden spawn up to five times in the Gulf of Mexico from October to April. The eggs

hatch and larvae drift into estuaries from January to April. Juveniles then develop in

shallow, lower-salinity estuarine and wetland habitats, moving in dense schools.

Eventually, the menhaden migrate to deeper waters and then move offshore and become

harvestable in their second year of life (Guillory et al. 1983). Immatures and adults

migrate into estuarine waters from April to October (Christmas et al. 1982).

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Behind Gulf menhaden, the top finfish landings, by weight, for the State of Louisiana in

2008 were catfish and bullheads, buffalofishes, black drum, striped mullet, herrings, tuna,

and sheepshead (NMFS Fisheries Statistics Division 2009 – personal communication).

For ports in the immediate vicinity of the project area (Dulac-Chauvin, Golden MeadowLeeville, and Morgan City-Berwick) total finfish landings in 2008 were approximately

4.2 million pounds with a dockside value of $6.8 million (NMFS Fisheries Statistics

Division 2009 – personal communication). The top finfish landings by weight in 2008

for these ports were yellowfin tuna, black drum, blue catfish, swordfish, and herrings.

Although gulf menhaden are an important resource in and around the project area, the

vast majority of landings for this species are reported at other ports.

Commercial landings (by weight) of fish and shellfish, including freshwater fish, at ports

within or in the immediate vicinity of the project area have been on a gradually declining

trend over the past 25 years (NMFS Fisheries Statistics Division 2009 – personal

communication). Fluctuations in year to year landings can be caused by a variety of

factors including winter freezes, drought, tropical storms, and transportation costs, and

usually do not indicate long-term environmental problems. Individual organisms produce

large numbers of eggs, so populations can recover quickly from short-term detrimental

conditions. However, longer-term declines in landings can signify that there are ongoing

environmental problems and/or over-fishing of the resource or a weakening market.

An extensive database of fishery independent sampling data for fish and shellfish is

maintained by the Louisiana Department of Wildlife and Fisheries. The database

contains information on extensive sampling conducted in the coastal marshes, bayous,

and lakes in and around the project area. USACE personnel requested fish and shellfish

species information from LDWF for all sampling stations in the vicinity of the project

area. Due to the size of the database and lack of any summarized information, data from

1998-2008 for 3 sampling stations located within the project area utilizing different

capture techniques were chosen to characterize the fish assemblage in the project area.

The most abundant finfish species from otter trawl data collected in the Lake Mechant

area were bay anchovy, Atlantic croaker, spot, Gulf menhaden, and sand seatrout. White

shrimp, blue crab, and brown shrimp were commonly collected as well. Gillnet samples

in the Catfish Lake area showed spotted seatrout, Gulf menhaden, spot, Atlantic croaker,

sea catfish, and black drum to be the most abundant species. The most abundant species

collected from Lake Boudreaux by seine were bay anchovy, inland silverside, naked

goby, Atlantic croaker, and Gulf killifish. Grass shrimp, brown shrimp, blue crab, and

white shrimp were also common.

The most abundant species found in freshwater marsh in the study area are sheepshead

minnow, rainwater killifish, inland silverside, and sailfin molly (Rogers et al. 1992).

These species are found along marsh edges and among SAV. The intermediate and fresh

marshes also provide habitat for commercial and recreational fisheries. Species include

largemouth bass, black crappie, bluegill, channel catfish, buffalo, freshwater drum,

bowfin, and gar.

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Table 4.8 displays the trends and projections through the year 2050 of fish and

invertebrate species found in mapping units in the project area as reported in the Coast

2050 report (LCWCRTF and WCRA 1998). Trends for fish and invertebrate species

were based on fishery independent sampling data and field knowledge of area biologists.

Future projections of fish and invertebrate abundance were based on the projected percent

and pattern of wetland loss in each mapping unit and the anticipated resultant impacts to

the fishery.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 4.8. Trends and Projections through 2050 of Fish and Invertebrates in the Project Area (LCWCRTF and WCRA 1998).

Mapping Unit

Fish and Invertebrate Guilds (Species)

Red Drum Black Drum

Spotted

Seatrout

Gulf

Menhaden

SouthernFlounder

American

Oyster

White

Shrimp

Brown

Shrimp Blue Crab

Spanish

Mackerel

Largemouth

Bass

Channel

Catfish

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Trend /

Projection

Penchant I/Sy I/Sy D/D D/Sy D/D D/I D/Sy D/Sy I/Sy NA/NA D/I U/U

Mechant / deCade I/D I/D D/D I/D D/D I/I Sy/D I/D I/D I/I D/Sy D/Sy

North HoumaShip CanalWetlands

I/D I/D I/D I/D I/D NA/NA I/D I/D I/D NA/NA D/I D/I

Boudreaux I/D I/D D/D I/D D/D I/I Sy/D I/D I/D NA/NA D/I D/ISt. Louis Canal I/D I/D D/D I/D D/D I/Sy Sy/D I/D I/D NA/NA D/I D/I

North BullyCamp I/D I/D D/D D/D D/D D/I D/D D/D I/D I/I NA/NA NA/NA

Sy = Steady; D = Decrease; I = Increase; U = Unknown; NA = Not Applicable

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4.2.9.1.2 Shrimp

Brown and white shrimp spawn in the Gulf of Mexico. Larvae drift into estuarine waters

as postlarvae and inhabit coastal wetlands. After becoming juveniles, the shrimp move

offshore where they become adults. There may be up to three spawns per year in

Louisiana (Gaidry and White 1973) with females each producing from a half million to a

million eggs. Brown shrimp wash into estuaries mainly from February to April (White

and Boudreaux 1977) while white shrimp come in from late spring to autumn when

temperatures are above 25°C (Baxter and Renfro 1967). White shrimp spawn in

shallower Gulf water and move further into estuarine nursery areas [up to 160km (99

miles)] as postlarvae and juveniles than brown shrimp (Turner and Brody 1983). Brown

shrimp leave the estuaries to the Gulf of Mexico from May through August (Lassuy

1983) whereas white shrimp leave from September to December (Muncy 1984).

Recruitment of shrimp to the fishery is not dependent on parent stocks the year before

because environmental conditions are the overriding factor (Muncy 1984). Recruitment

of brown shrimp increased in the Gulf from 1960-1986 despite a two-fold increase in

catch effort and catch. White shrimp showed similar trends, but the catch per unit effort

declined slightly, indicating that recruitment cannot maintain a stable catch per unit effort

as effort increases (Nance and Nichols 1988). The optimum salinity for brown shrimp

survival and growth in the estuary appears to be around 19 ppt, but salinities from 15 to

20 ppt are very favorable (Barrett and Gillespie 1973). White shrimp can apparently do

well in water with lower salinities than this. Both species prefer shallow, soft-bottomed

estuaries (Muncy 1984; Lassuy 1983). Water temperatures over 20°C after the first week

in April are also important. Production of brown shrimp in Barataria Bay and Caminada

Bay is inversely related to average spring (March-May) Mississippi River discharge. The

same type of relationship holds for white shrimp, but it is related to average summer

Mississippi River discharge. The Atchafalaya River discharges emulate the same trends

as the Mississippi River, so similar relationships would be expected between production

of shrimp and discharge (Barrett and Gillespie 1973).

Shrimp yields have been related to wetland habitat quantity (Turner 1992) and land-water

interface. The land-water interface relationship suggests that shrimp yields will decrease

when the land-water interface declines. Browder et al. (1989) predicted that brown

shrimp catches in the Barataria, Timbalier, and Terrebonne Basins would peak around the

year 2000 and may fall to zero within 52 to 105 years. This prediction seems to follow

the catch trends observed in recent years as brown shrimp landings for Louisiana have

generally been declining since 2001, with 2008 landings being less than 40% of 2001

landings (NMFS Fisheries Statistics Division 2009 – personal communication). White

shrimp landings for the same period were fairly stable.

Gulf region landings of shrimp in 2008 were the Nation’s largest with 178.7 million

pounds and 90 percent of the national total. In Louisiana, a total of 24.9 million pounds

of brown shrimp and 63.1 million pounds of white shrimp were landed in 2008, with a

dockside value of $22.7 million and $107.4 million, respectively (NMFS 2009). For

ports in and around the project area, a total of 10.6 million pounds of brown shrimp and

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20.4 million pounds of white shrimp were landed in 2008, with a dockside value of $9.2

million and $32.2 million, respectively (NMFS Fisheries Statistics Division 2009 –

personal communication).

4.2.9.1.3 Blue Crab

Blue crabs occupy all estuarine aquatic habitats at some time during their life cycle,

tolerating a wide array of salinities and temperatures, but preferring lower to moderate

salinity (Perry and McIlwain 1986). Temperatures above 30°C for prolonged periods are

stressful. Blue crabs are benthic omnivores, feeding on various crustaceans, mollusks,

fish, and detritus. Eggs are produced in two batches averaging 1,500,000 eggs in each.

Larval blue crabs reach their peak during February and March (Adkins 1972). Juveniles

are most abundant from November to May and occur in the northern portions of the

estuaries. The juveniles prefer areas with soft, mud substrate. After 1-1.5 years, the

crabs then move from shallow areas into larger bays and bayous as adults where they live

for at least one more year. Mating occurs in the spring after which time the females

migrate southward to higher salinity waters (Adkins 1972; Perry 1975).

Louisiana is the leading blue crab producer, by weight, in the U.S., producing 26.5

percent of the nation’s total in 2008 (NMFS 2009). Statewide, a total of 41.5 million

pounds of blue crab were landed in 2008, with a dockside value of $31.8 million (NMFS

2009). For ports in and around the project area, a total of 15.6 million pounds of blue

crab were landed in 2008, with a dockside value of $11.9 million (NMFS Fisheries

Statistics Division 2009 – personal communication).

4.2.9.1.4 Oyster

The eastern oyster is indigenous to coastal Louisiana and provides a rich ecological and

commercial resource. Salinity plays a key role in oyster sustainability. Adult oysters can

tolerate salinities from 0 to 42 ppt, but the optimal range is 5-15 ppt. Fresher waters fail

to support biological function, and more saline waters promote disease and predation.

Adult oysters are more prone to impacts from changes in water quality than commercially

harvested fishes and crustaceans because they are sessile and cannot relocate in response

to changes in water quality parameters.

The Gulf region led the U.S. in oyster production in 2008 with 20 million pounds, 89

percent of the national total (NMFS 2009). In Louisiana, a total of 12.8 million pounds

of oyster were harvested in 2008, with a value of $38.8 million (NMFS 2009). The

central region of Louisiana, which includes the Terrebonne estuary, supplies 26 percent

of the oyster landings in Louisiana (Keithly and Roberts 1988). Production of oysters in

Louisiana has been relatively stable for the last 50 years, with harvest from public beds

replacing the decreasing harvest from private leases. However, increasing coastal land

loss is reducing the amount of marsh that provides shelter to reefs, and saltwater intrusion

is exacerbating disease and predation.

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Oyster leases are located largely outside of the study area, although a fair number exist in

Lake Mechant, Lake Boudreaux, and the Grand Bayou basin within the project boundary.

Oyster seed grounds within the project area are located in Lake Mechant. The seed

grounds are managed by the LDWF to produce a ready supply of seed oysters that can be

planted on private leases for later harvest. The locations of oyster leases and seed

grounds in the vicinity of the study area are shown in figure 4.7.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.7. Oyster Seed Grounds and Leases (August 2009 Louisiana Department of Wildlife and Fisheries data).

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4.2.10 Essential Fish Habitat (EFH)

This resource is institutionally significant because of the Magnuson-Stevens Act of 1996

(Public Law 104-297). Essential Fish Habitat (EFH) is technically significant because, as

the Act states, EFH is “those waters and substrate necessary to fish for spawning,

breeding, feeding or growth to maturity." EFH is publicly significant because of the high

value that the public places on the seafood and the recreational and commercial

opportunities EFH provides.

4.2.10.1 Historic and Existing Conditions

In a letter dated 17 February 2009, the NMFS indicated fishery resources in the project

area include aquatic and tidally influenced wetland habitats that are designated as

essential fish habitat for postlarval and juvenile life stages of brown shrimp and white

shrimp, red drum, and gulf stone crab managed by the Gulf of Mexico Fishery

Management Council (GMFMC). Essential fish habitat for various life stages of these

species can be found in Table 4.9.

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Table 4.9. Essential Fish Habitat for Various Life Stages of Brown Shrimp, White Shrimp, Red

Drum, and Gulf Stone Crab (GMFMC 2004).

Species Life Stage Zone EFH

Brown

Shrimp

Eggs Marine 18-110 meters; sand / shell

bottoms, soft bottoms

Larvae / Presettlement PostlarvaeMarine/Estuarine 0-82 meters; pelagic

Late Postlarvae /

Juveniles

Estuarine 0-18 meters; oyster reefs,

emergent marshes, sand / shell

bottoms, SAV, soft bottoms

Adults Marine 14-110 meters; sand / shell

bottoms, soft bottoms

White

Shrimp

Eggs Marine 9-34 meters; sand / shell

bottoms, soft bottoms

Larvae / Presettlement PostlarvaeMarine/Estuarine 1-82 meters; pelagic

Late Postlarvae /

Juveniles

Estuarine 1-30 meters; emergent marshes,

soft bottoms

Adults Marine 9-34 meters; soft bottoms

Red

Drum

Eggs Marine Pelagic

Larvae / Postlarvae Estuarine Sand/shell bottoms, SAV, soft

bottoms, emergent marshes

Early Juveniles / Late

Juveniles

Estuarine/Marine 0-5 meters; emergent marshes,

SAV, soft bottoms, hard

bottoms, sand / shell bottoms

Adults Estuarine/Marine 1-70 meters; hard bottoms,

pelagic, emergent marshes, sand

/ shell bottoms, SAV, soft

bottoms

Gulf

Stone

Crab

Eggs Estuarine/Marine 0-40 meters; sand / shell

bottoms, soft bottoms

Larvae / Postlarvae Estuarine/Marine 0-40 meters; pelagic

Post-settlement

Juveniles / Late

Juveniles

Estuarine 0-40 meters; oyster reefs, sand /

shell bottoms, soft bottoms

Adults Estuarine 0-40 meters; oyster reefs, sand /

shell bottoms, soft bottoms

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4.2.11 Threatened and Endangered Species

This resource is institutionally significant because of the Endangered Species Act of

1973, as amended, and the Marine Mammal Protection Act of 1972. Endangered (E) and

threatened (T) species are technically significant because the status of such species

provides an indication of the overall health of an ecosystem. These species are publicly

significant because of the desire of the public to protect them and their habitats.

4.2.11.1 Historic and Existing Conditions

Federal Designation. Within the study area there are several animal species (some with

critical habitats) under the Federal jurisdiction of the USFWS and/or the NMFS,

presently classified as endangered or threatened (Table 4.10).

Table 4.10. Threatened and Endangered Species in the Study Area.

Species Critical Habitat Status Jurisdiction

Federal State USFWS NMFS

West Indian Manatee

(Trichechus manatus) E E X

Brown Pelican (Pelecanus

occidentalis) De-listed December 17, 2009.

Piping Plover (Charadrius

melodus)

X

(foraging, sheltering, and

roosting habitat of wintering

populations)

T T X

Hawksbill sea turtle

(Eretmochelys imbricata) E E X X

Kemp’s Ridley sea turtle

(Lepidochelys kempii) E E X X

Leatherback sea turtle

(Dermochelys coriacea) E E X X

Green sea turtle (Chelonia

mydas) T T X X

Loggerhead sea turtle

(Caretta caretta) T T X X

Pallid Sturgeon

(Scaphirhynchus albus) E E X

Gulf Sturgeon (Acipenser

oxyrinchus desotoi) T T X X

The following information on threatened and endangered species was obtained by letter

from the USFWS dated 21 January 2009.

Federally listed as endangered, West Indian manatees occasionally enter Lakes

Pontchartrain and Maurepas, and associated coastal waters and streams, during the

summer months. Manatees have been reported in the Amite, Blind, Tchefuncte, and

Tickfaw Rivers, and in canals within the adjacent coastal marshes of Louisiana. They

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have also been occasionally observed elsewhere along the Louisiana Gulf Coast. The

manatee has declined in numbers due to collisions with boats and barges, entrapment in

flood control structures, poaching, habitat loss, and pollution. Cold weather and

outbreaks of red tide may also adversely affect these animals.

Federally listed as a threatened species, the piping plover, as well as its designated critical

habitat, occur along the Louisiana coast. Piping plovers winter in Louisiana, and may be

present for 8 to 10 months. They arrive from the breeding grounds as early as late July

and remain until late March or April. Piping plovers feed extensively on intertidal

beaches, mudflats, sandflats, algal flats, and wash-over passes with no or very sparse

emergent vegetation; they also require non-vegetated or sparsely vegetated areas for

roosting. Roosting areas may have debris, detritus, or micro-topographic relief offering

refuge to plovers from high winds and cold weather. In most areas, wintering piping

plovers are dependent on a mosaic of sites distributed throughout the landscape, because

the suitability of a particular site for foraging or roosting is dependent on local weather

and tidal conditions. Plovers move among sites as environmental conditions change, and

studies have indicated that they generally remain within a 2-mile area.

On July 10, 2001, the U.S. Fish and Wildlife Service designated critical habitat for

wintering piping plovers (Federal Register Volume 66, No. 132). Their designated

critical habitat identifies specific areas that are essential to the conservation of the

species. The primary constituent elements for piping plover wintering habitat are those

habitat components that support foraging, roosting, and sheltering and the physical

features necessary for maintaining the natural processes that support those habitat

components. Constituent elements are found in geologically dynamic coastal areas that

contain intertidal beaches and flats (between annual low tide and annual high tide), and

associated dune systems and flats above annual high tide. Important components (or

primary constituents elements) of intertidal flats include sand and/or mud flats with no or

very sparse emergent vegetation. Adjacent non-vegetated or sparsely vegetated sand,

mud, or algal flats above high tide are also important, especially for roosting plovers.

Major threats to this species include the loss and degradation of habitat due to

development, disturbance by humans and pets, and predation.

The pallid sturgeon is an endangered fish found in both the Mississippi and Atchafalaya

Rivers (with known concentrations in the vicinity of the Old River Control Structure

Complex); it is possibly found in the Red River as well. The pallid sturgeon is adapted to

Riverine conditions that can be described as large, free-flowing, turbid water with a

diverse assemblage of physical habitats that are in a constant state of change. Detailed

habitat requirements of this fish are not known, but it is believed to spawn in Louisiana.

Habitat losses through river channelization and dam construction have affected this

species throughout its range.

The Gulf sturgeon, federally listed as a threatened species, is an anadromous fish that

occurs in many rivers, streams, and estuarine waters along the northern Gulf coast

between the Mississippi River and the Suwanee River, Florida. In Louisiana, the Gulf

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sturgeon has been reported at Rigolets Pass, rivers and lakes of the Lake Basin, and

adjacent estuarine areas. Spawning occurs in coastal rivers between late winter and early

spring (i.e., March to May). Adults and sub-adults may be found in those rivers and

streams until November, and in estuarine or marine waters during the remainder of the

year. Sturgeons, less than two years old, appear to remain in Riverine habitats and

estuarine areas throughout the year, rather than migrate to marine waters. Habitat

alterations such as those caused by water control structures that limit and prevent

spawning, poor water quality, and over-fishing have negatively affected this species.

On March 19, 2003, the Service and the National Marine Fisheries Service published a

final rule in the Federal Register (Volume 68, No. 53) designating critical habitat for the

Gulf sturgeon in Louisiana, Mississippi, Alabama, and Florida. Portions of the Pearl and

Bogue Chitto Rivers, Lake Pontchartrain east of the Lake Pontchartrain Causeway, all of

Little Lake, The Rigolets, Lake St. Catherine, and Lake Borgne within Louisiana were

included in that designation. The primary constituent elements essential for the

conservation of Gulf sturgeon are those habitat components that support feeding, resting,

sheltering, reproduction, migration, and physical features necessary for maintaining the

natural processes that support those habitat components. The primary constituent

elements for Gulf sturgeon critical habitat include:

• abundant prey items within Riverine habitats for larval and juvenile life stages,

and within estuarine and marine habitats for juvenile, sub-adult, and adult life

stages;

• riverine spawning sites with substrates suitable for egg deposition and

development, such as limestone outcrops and cut limestone banks, bedrock, large

gravel or cobble beds, marl, soapstone, or hard clay;

• riverine aggregation areas, also referred to as resting, holding and staging areas,

used by adult, sub-adult, and/or juveniles, generally, but not always, located in

holes below normal riverbend depths, believed necessary for minimizing energy

expenditures during freshwater residency and possibly for osmoregulatory

functions;

• a flow regime (i.e., the magnitude, frequency, duration, seasonality, and rate-ofchange of freshwater discharge over time) necessary for normal behavior, growth,

and survival of all life stages in the riverine environment, including migration,

breeding site selection, courtship, egg fertilization, resting, and staging; and

necessary for maintaining spawning sites in suitable condition for egg attachment,

egg sheltering, resting, and larvae staging;

• water quality, including temperature, salinity, ;pH, hardness, turbidity, oxygen

content, and other chemical characteristics, necessary for normal behavior,

growth, and viability of all life stages;

• sediment quality, including texture and other chemical characteristics, necessary

for normal behavior, growth, and viability of all life stages; and

• safe and unobstructed migratory pathways necessary for passage within and

between riverine, estuarine, and marine habitats (e.g., a river unobstructed by a

permanent structure, or a dammed river that still allows for passage).

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Additionally, as discussed in the Gulf sturgeon critical habitat final rule, the jurisdiction

for Section 7 consultation is shared between the Service and NMFS. The Service is

responsible for consultations on the Gulf surgeon and its critical habitat in riverine units.

In estuarine units, the NMFS will consult with the Corps (responsibilities are divided

based upon the action agency). The NMFS is responsible for consultations in marine

units. For Federal projects that extend into the jurisdiction of both Services (such as the

proposed project) the Service will be the lead consulting agency and will consult

internally with NMFS.

Endangered and threatened sea turtles forage in the nearshore waters, bays and sounds of

Louisiana. The NMFS is responsible for aquatic marine threatened or endangered

species. However, the Service is responsible for endangered and threatened sea turtles

when they are on land (i.e., nesting), which may occur on the Chandeleur Islands and/or

other barrier islands.

The brown pelican was listed as endangered when project endangered species

coordination with USFWS began in early 2009. However, due to successful recovery

efforts, the brown pelican was removed from the Federal list of endangered and

threatened wildlife effective December 17, 2009 (Federal Register, Volume 74, Number

220). The brown pelican is still protected under the Migratory Bird Treaty Act.

State Designation. The Louisiana Natural Heritage Program (LNHP) founded in 1984

through a partnership with the State of Louisiana and The Nature Conservancy, is

maintained by the Louisiana Department of Wildlife and Fisheries. The Louisiana

Natural Heritage Program was founded with the goal of developing and maintaining a

database on rare, threatened and endangered species of plants and animals, and natural

communities for Louisiana. The Louisiana Natural Heritage Program lists 50 species or

communities as occurring in Terrebonne and Lafourche parishes, including federally

listed species (Table 4.11).

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Table 4.11. Rare, Threatened, and Endangered Species and Natural Communities of Terrebonne

and Lafourche Parishes – April 2008 (Louisiana Natural Heritage Program).

Common Name Scientific Name State Rank*

Cooper’s Hawk Accipiter cooperii S2B, S3N

Gregg’s Amaranth Amaranthus greggii S3

Swamp Milkweed Asclepias incarnata S2

Brackish Marsh Brackish marsh S3S4

Red Wolf Canis rufus SX

Golden Canna Canna flaccida S4?

Cypress-knee Sedge Carex decomposita S3

Big Sandbur Cenchrus myosuroides S1

Dune Sandbur Cenchrus tribuloides S2

Floating Antler-fern Ceratopteris pteridoides S2

Sand Dune Spurge Chamaesyce bombensis S1

Snowy Plover Charadrius alexandrinus S1B, S2N

Piping Plover Charadrius melodus S2N

Wilson’s Plover Charadrius wilsonia S1S3B, S3N

Coastal Dune Grassland Coastal dune grassland S1S2

Coastal Dune Scrub thicket Coastal dune shrub thicket S1

Coastal Live Oak-hackberry Forest Coastal live oak-hackberry forest S1S2

Coastal Mangrove-marsh Shrubland Coastal mangrove-marsh shrubland S3

Hairy Comb Fern Ctenitis submarginalis S1

Cypress-tupelo Swamp Cypress-tupelo swamp S4

Reddish Egret Egretta rufescens S2B, S2N

Creeping Spike-rush Eleocharis fallax S1?

Canada Spikesedge Eleocharis geniculata S1?

Rooted Spike-rush Eleocharis radicans S1?

Peregrine Falcon Falco peregrinus S2N

Freshwater Marsh Freshwater marsh S1S2

Gull-billed Tern Gelochelidon nilotica S2B, S2S3N

Bald Eagle Haliaeetus leucocephalus S2N, S3B

Caspian Tern Hydroprogne cospia S1S2B, S3N

Coast Indigo Indigofera miniata S1

Common Water-willow Justicia americana S2

Diamondback Terrapin Malaclemys terrapin S2

Marine Submergent Vascular Vegetation Marine submergent vascular vegetation

Eastern Glass Lizard Ophisaurus ventralis S3

Osprey Pandion haliaetus S2B, S3N

Brown Pelican Pelecanus occidentalis S2

Coastal Ground Cherry Physalis angustifolia S1?

Roseate Spoonbill Platalea ajaja S3

Millet Beakrush Rhynchospora miliacea S2

Sand Rose-gentian Sabatia arenicola S1

Vegetated Pioneer Emerging Delta Sagittaria latifolia-Sagittaria platyphylla-(Colocasia

esculenta) Deltaic Herbaceous Vegetation

S2S3

Salt Marsh Salt marsh S3S4

Scaevola Scaevola plumieri SH

Gull Bluestem Schizachyrium maritimum S1

Scrub/shrub Swamp Scrub/shrub swamp S4S5

Estuarine Submergent Vascular Vegetation Submergent vascular vegetation (estuarine) S1S2

Manatee Trichechus manatus SZN

Arrow-grass Triglochin striata S1

Sea Oats Uniola paniculata S2

Waterbird Nesting Colony Waterbird nesting colony SNR

* State Element Ranks: S1 = critically imperiled in Louisiana because of extreme rarity; S2 = imperiled in Louisiana

because of rarity; S3 = rare and local throughout state or found locally in a restricted region; S4 = apparently secure in

Louisiana; S5 = demonstrably secure in Louisiana; SH = of historical occurrence in Louisiana but no recent records

verified within last 20 years; SX = believed to be extirpated from Louisiana; SZ = transient species; B = breeding

occurrence; N = nonbreeding occurrence; NR = No Rank; S? = rank uncertain.

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4.2.12 Cultural and Historic Resources

The cultural resources portion of this feasibility study provides a synthesis of previous

investigations in the project area that includes the locations and available information for

surveys and sites reported, thus facilitating the expeditious planning and implementation

of the resulting project (see report with images at Appendix F). The primary purpose of

cultural resources identification is to provide recommendations that will assist project

managers, engineers, and other decision-makers in the avoidance of adverse impacts.

The current feasibility study is limited to literature and records review and sample survey

as set forth in ER 1105-2-100 paragraph 5 (Feasibility Phase Studies). There has been no

evaluation and testing, intensive survey/inventory, or mitigation.

In accordance with ER 1105-2-100, Appendix C, paragraph C-4(d)(5)(d)(2), the U.S.

Army Corps of Engineers (USACE) elected to fulfill its obligations under Section 106 of

the National Historic Preservation Act of 1966, as amended, through the execution and

implementation of a Programmatic Agreement. In consultation with the Advisory

Council on Historic Preservation (ACHP), Louisiana State Historic Preservation Officer

(SHPO), Indian tribes, representatives of local governments, and other consulting parties,

the USACE developed a Programmatic Agreement among the USACE, Coastal

Protection and Restoration Authority of Louisiana, SHPO, and ACHP, pursuant to 36

CFR § 800.14(b)(1), executed July 29, 2010 (Appendix F). The Programmatic

Agreement establishes the procedures for consultation, identification of historic

properties, assessment and resolution of adverse effects. A copy of the PA appears at

Appendix F. Discovery of cultural resources and determinations of significance

presented in this section are drawn from archaeological survey reports and site recording

documents housed at the State Historic Preservation Office (SHPO) in Baton Rouge,

Louisiana. Both SHPO and THPO notification was undertaken to prepare concerned

parties for future project possibilities (see correspondence at Appendix F). Regular

meetings with SHPO and the Louisiana State Archaeologist were supplemented by email

correspondence in an effort to work in concert with the interests of the State and its

citizens. Visits to potentially impacted loci within the project area were undertaken over

two days on May 6, 2009 and May 7, 2009.

The standard for site significance adheres to the criteria established by the National

Register of Historic Places (NRHP) and outlined within 36 CFR 60.4. The standard for

“significance” as it applies to archaeological sites includes 1) sites that “possess integrity

of location, design, setting, materials, workmanship, feeling, and association,”

2) sites that are “associated with events that have made a significant contribution to the

broad patterns of our history,” 3) sites that are “associated with the lives of persons

significant in our past,” 4) sites that “embody the distinctive characteristics of a type,

period, or method of construction,” or “represent the work of a master,” “possess high

artistic values,” or “represent a significant and distinguishable entity whose components

may lack individual distinction,” or 5) sites that “have yielded, or may be likely to yield,

information important to prehistory, or history.”

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The study area comprises approximately 1100 square miles, or 700,000 acres, that

includes four primary geologic regions. The full array, of 61 project features, has a total

temporary right of way of approximately 3497 acres. This represents the area of direct

impact. However, the intent of this project is to deliver fresh water in quantities such that

the broader area of impact has yet to be determined. As such, the total area of potential

effect (APE) cannot be mapped at this time.

There are 290 known archaeological sites within the proposed project area. Of these, 283

are represented within the project GIS database by polygon features and seven by points.

This dataset was derived from both the on-line dataset of the Louisiana Division of

Archaeology and sites digitized manually after a visual examination of the legacy 7.5

minute quad maps at the Louisiana State Historic Preservation Office. One

archaeological site thought to be in the area (16TR80) is not in the on-line dataset and

was not located on the quad maps. The site files for the majority of these sites do not list

their National Register status.

4.2.12.1 Historic Conditions

The historic properties aspect of this feasibility study has the dual objective of identifying

cultural resources and site variability within the diverse biomes of the coastal Louisiana

marshes. The wetlands and natural levees comprise seven biotic communities that

sustained over four-hundred-fifty readily identifiable plant and animal species, providing

a vast resource base for human subsistence. Underlying these biotic communities are the

depositional environments that comprise the geomorphic history of the Terrebonne

Marshes project area. Depositional environments include fluvial features, such as the

natural levees, marshes, inland swamps, and lakes that support the distinctive biotic

communities previously mentioned. These features can be identified from maps and

remote imagery, from their distinctive lithological composition, and via various dating

techniques including radiocarbon (14C) and thermoluminescence (TL). Understanding

the relationship between sites and landforms helps archaeologists to both develop

probabilistic models and locate cultural resources. The effort for this study has been to

develop such a model for current and future planning.

Biological and environmental diversity in the coastal Louisiana marshes has supported

nomadic and settled subsistence regimes for human populations dating to at least 1000

B.C. Abundant archaeological evidence indicates a settlement pattern concentrated on

stable landscape features such as the natural levees flanking bayous, both active and

inactive, in the study area. To date, approximately three hundred archaeological sites

have been identified in the Terrebonne marshes and along the lobes of the LafourcheTerrebonne Delta. Given the nature of the terrain it is supposed that many Native

American traditional cultural properties, and or sacred sites have not been recorded. In

some cases, these areas cannot be identified without the assistance of the tribes. Thus, we

have requested tribal assistance in identifying such areas within the project boundaries.

The recoverable settlement history for the Terrebonne marshes appears to be tied to the

deposition and subsequent stabilization of the Lafourche-Terrebonne Delta between 2000

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and 0 B.C. Relict beaches and channels of the delta provided early human foragers with

locations to which they returned in seasonal rounds of hunting and collecting. Repeated

use of these places is attested by deposits of shells from the bivalve Rangia cuneata, a

brackish-water clam. These shell deposits, or middens, contain both faunal and human

remains and culturally produced artifacts including pottery, which is used to tie

occupations at these sites to a relative chronology that is supported by radiocarbon (14C)

assay from other archaeological sites. Lenses of sediment frequently appear interspersed

within layers of shell, attesting to episodic overbanking along levees, and artifacts

indicate that sites may have been abandoned for extended periods, possibly due to

elevated water levels. The density of settlements associated with different periods of

occupation along Bayous Boeuf, Black, Shaffer, Chene, Mauvais Bois, De Cade, Du

Large, Terrebonne, and Bayou Pointe au Chien, all natural levee landforms with sites

dispersed at several hundred meter intervals, may reflect a shifting settlement system in

response to this variable water table.

Significant sites were visited repeatedly and many habitation loci that were clearly

established in prehistory continued to be utilized through the post-bellum period.

Settlements in the Terrebonne marshes have been dated to major cultural periods from

the pre-ceramic Poverty Point (2000-500 B.C.) through Tchula-Tchefuncte (500-0 B.C.),

Marksville (A.D. 0-400), Baytown-Troyville (A.D. 400-700), Coles Creek (A.D. 700-

1000), the Mississippian (or Plaquemine) (A.D. 1200-1700), and into Colonial and

modern historic times. A sugar economy dominated the agrarian market from the late

1840s through the Civil War, with some thirty to forty plantations eventually constructed

along Bayous Boeuf, Shaffer, Black, Du Large, and parts of the Lower Atchafalaya

River. Confederate fortifications were established at the confluence of Bayous Shaffer

and Chene, and on the west bank of the Atchafalaya River at its junction with Little Wax

Bayou. Subsequent Union army occupation of the entire study area, as far west as

Berwick Bay, produced additional fortifications along the northernmost edge of the

Terrebonne marshes. Restoration period economic activity continued to focus on sugar

under a share-crop system supplemented by shell fish production and to a lesser extent

lumber extraction. After the early 20th century discovery of oil and gas these industries

have dominated the regional economy.

4.2.12.2 Existing Conditions

There are eight (8) locations listed on the National Register than are within the project

boundary (Table 4.12). There are an additional six (6) locations within a one kilometer

radius of the area. Of these National Register locations, only the Wesley House is

located in close proximity to a potential project feature being within 100 meters of

features CC2 and CD4. A private cemetery associated with the Wesley House is within

the APE of CD4 (see discussion of the Gagne Cemetery at end of Appendix F).

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Table 4.12. NR listed properties within project boundary.

Name

Date

Published Address Location Description

Atkinson Memorial

Presbyterian Church 3/19/91 214 Fourth Street Morgan City Gothic Revival Bld

Brubaker House 2/29/95 1102 Second Street Morgan City Stick/Eastlake Bld

Gibson Methodist Episcopal

Church 5/8/86 S. Bayou Black Drive Gibson Greek Revival Bld

Montegut School 10/7/93 1137 LA 55 Montegut Building

Morgan City Historic District 1/9/86 N/A Morgan City District

Residence Plantation House 9/8/01 8951 Park Avenue Houma Stick/Eastlake Bld

U. S. Post Office 12/17/82 1st and Everett Streets Morgan City Beaux Arts Bld

Wesley House 8/11/82 1210 E. Main Street Houma Greek Revival Bld

Continuous prehistoric settlement from the Poverty Point through Mississippian periods

is followed by historic occupation primarily focused on natural levees and alluvial

deposits. These elevated landforms are significantly more likely to contain

archaeological deposits and are considered higher probability locations for cultural

resources.

Assuming a typical survey corridor of 100 meters, a total of 19,910 acres within the

proposed project area have been recorded as having undergone an archaeological survey.

This amounts to just under three percent of the total area. This number may be an

underestimate as many recorded sites fall outside the recorded survey tracks. Forty-eight

surveys are recorded for the study area. Earliest recorded observations of archaeological

sites within the study area date to 1806 and identify what must be prominent mounds.

Regular expeditions into the marshes recorded habitation sites throughout the project area

since that early visit.

4.2.13 Aesthetics

This resource is institutionally important because of the laws and policies that affect

visual resources, most notably the 1969 National Environmental Policy Act. Visual

resources are publicly and technically important because of the high value placed on the

preservation of unique natural and culture landscapes.

4.2.13.1 Historic and Existing Conditions

Ecoregion information has been identified for the study area. The information was

adapted from (Daigle et al. 2006). The ecoregions are described below and in Figure 4.8.

The study area’s natural landscape visual characteristics are derived from its Mississippi

Alluvial Plain setting. This ecoregion extends from southern Illinois, at the confluence of

the Ohio River with the Mississippi River, south to the Gulf of Mexico. The Mississippi

River watershed drains all or parts of thirty-one states, two Canadian provinces, and

approximately 1,243,000 square miles before the river finally reaches the Gulf. The

Mississippi Alluvial Plain is mostly a broad, flat alluvial plain with river terraces, swales,

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and levees providing the main elements of relief. Winters are mild and summers are hot,

with temperatures and precipitation increasing from north to south. Bottomland

deciduous forest covered the region before much of it was cleared for cultivation. The

ecoregion contained one of the largest continuous wetland systems in North America.

The widespread loss of forest and wetland habitat, however, has impacted wildlife and

reduced bird populations, although it is still a major bird migration corridor. Today,

constructed levees restrict the river from overflowing, opening large areas for extensive

agricultural use. Almost the entire region is in cropland. In Louisiana, cotton, corn,

soybeans, pasture, and rice are major crops in the northern and central parts and

sugarcane, soybeans, and pasture are dominant in the southern part. Between the levees

that parallel the Mississippi River is a corridor known as the “batture lands.” The batture

lands are hydrologically connected to the Mississippi River, are flood-prone, and contain

remnant habitat for “big river” species (e.g., pallid sturgeon) as well as river-front plant

communities. The sub-ecoregions Southern Holocene Meander Belts, Inland Swamps,

and the Deltaic Coastal Marshes and Barrier Islands further define the study area’s

landscape visual characteristics.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.8. Ecoregions in the Project Area.

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The Southern Holocene Meander Belts ecoregion stretches from just north of Natchez,

Mississippi south to New Orleans, Louisiana. The ecoregion is a flat to nearly flat

floodplain containing the meander belts of the present and past courses of the Mississippi

River. This ecoregion has a long growing season, warmer annual temperatures and more

precipitation than its northern Mississippi Alluvial Plain counterparts. The ecoregion

contains minor species such as live oak, laurel oak, and Spanish moss that are generally

not found in the more northerly regions. The bottomland forests have been cleared and

the region has been extensively modified for agriculture, flood control, and navigation.

The levee system is extensive throughout the region. Soybeans, sugarcane, cotton, corn,

and pasture are the major crops, with crawfish aquaculture common.

The Inland Swamps ecoregion marks a transition, ranging from the fresh waters of the

Southern Backswamps at the northern extent of the intratidal basins to the fresh, brackish,

and saline waters of the Deltaic Coastal Marshes and Barrier Islands ecoregion. It

includes a large portion of the Atchafalaya Basin. Swamp forest communities are

dominated by bald cypress and water tupelo. In areas where freshwater flooding is more

prolonged, the vegetative community is dominated by grasses, sedges, and rushes. This

region contains one of the largest bottomland hardwood forest swamps in North America.

The levees in place on either side of the Mississippi River have diverted much of the river

flow from its natural tendency to flow into the Atchafalaya Basin. Large concrete

structures prevent diversion into the Atchafalaya River, and flow from the Red River is

also controlled.

Brackish and saline marshes dominate the Deltaic Coastal Marshes and Barrier Islands

ecoregion. The region supports vegetation tolerant of brackish or saline water including

saltmarsh cordgrass, marshhay cordgrass, black needlerush, and coastal saltgrass. Black

mangrove occurs in a few areas, and some live oak is found on Grand Isle and along old

natural levees. The wetlands and marshes act as a buffer to help moderate flooding and

tidal inundation during storm events. Lack of sediment input, delta erosion, land

subsidence, and rising sea levels threaten the region.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.9. Landscape Similarity Zones in the Project Area.

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Seven landscape similarity zones have been identified for the study area (see Figure 4.9).

The zones are described below.

Urban 1

This zone encompassing the city of Houma is within the Southern Holocene Meander

Belts ecoregion. The area is characterized by the water resources that are the visual core

of the area including Bayous Terrebonne and Black and the Intracoastal Waterway. This

zone includes spaces that are prominent and contain landmarks or places of assembly that

have national and regional importance including the Houma Historic District located in

its downtown area. Development patterns are typical of tract-type subdivisions along

with older residential areas adjacent to the urban center of multi-family complexes. The

area includes commercial facilities including restaurants and retail establishments and

community facilities such as neighborhood parks, schools and athletic fields. The density

of development limits vegetation in some areas, and typical views are limited in the

downtown areas to the nearby streetscape due to multi-story commercial, residential and

municipal buildings. Visual access to adjacent areas is wider along the roads and

waterways and the less densely developed areas as one transitions out of the downtown

area. The Wetlands Cultural Scenic Byway provides viewsheds along LA 182 and LA

56.

Urban 2

This zone primarily is within the Inland Swamps ecoregion. It includes the downtown

area of Morgan City, characterized by the maritime related industry adjacent to the

downtown district. This zone includes spaces that are prominent and contain landmarks

or places of assembly that have national and regional importance including the Morgan

City Historic District. Development patterns are typical of tract-type subdivisions along

with older residential areas adjacent to the urban center of multi-family complexes. The

area includes commercial facilities including restaurants and retail establishments and

community facilities such as neighborhood parks, schools and athletic fields. Southern

viewsheds are limited as the downtown district faces Berwick Bay behind a twenty foot

seawall. The density of development limits vegetation in some areas, and typical views

are limited to the nearby streetscape. Visual access to adjacent areas is wider along the

roads and waterways and the less densely developed areas as one transitions out of the

downtown area.

Residential

This zone primarily is within the Deltaic Coastal Marshes and Barrier Islands ecoregion.

The area’s terrain is flat and follows the meandering bayous. The residential area is

characterized by the development that was driven by its proximity to the Gulf of

Mexico’s fisheries. Low-density rural development, typically limited to road frontage

lots, is prevalent. Small scale commercial seafood related industry is prevalent as one

travels LA 57 to Dulac and the Wetlands Cultural Scenic Byway’s LA 56 to Cocodrie.

The zone includes small retail facilities including restaurants and food stores and

community facilities such as neighborhood parks, schools and athletic fields. Visual

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access to the area is wider along roads and waterways and the less densely developed

areas.

Industrial

This zone primarily is within the Southern Holocene Meander Belts ecoregion and

adjacent to Morgan City’s urban area. Although residences and commercial facilities can

be located within this zone, maritime industrial uses, including resources for petroleum

and natural gas exploration, predominate. There is little canopy cover, but views are

typically diverted to the industrial development that lines LA 182 and Bayou Cocodrie.

Terrain is typically flat. Regional access to the area is from U.S. Route 90.

Agricultural

This zone is within the Southern Holocene Meander Belts ecoregion. This area is marked

primarily by flat, mostly open land associated with various bayous sometimes with

vegetation along the edges or between fields helping to define the space. Isolated small

citrus orchards are found within these areas. Associated low-density, rural development

along road frontages and at the various crossroads is included in this zone. The zone

includes small retail facilities including restaurants and food stores and community

facilities such as neighborhood parks, schools, and athletic fields. Panoramic views are

possible but may be limited by the interspersed pockets of forest vegetation. The

Wetlands Cultural Scenic Byway provides viewsheds along LA 182 from Houma to

Gibson and along LA 56 south of Houma.

Nonforested Wetlands

This zone is within the Deltaic Coastal Marshes and Barrier Islands ecoregion.

The terrain is mostly marsh interspersed with numerous lakes, ponds, bayous, and canals.

Man made features include petroleum and natural gas wells, and the Gulf-Intracoastal

Waterway. Public recreation access areas include Mandalay National Wildlife Refuge

and Pointe Au Chien Wildlife Management Area. Physical access to most of the area is

limited to boat travel that allows for panoramic viewsheds of the area. The Wetlands

Cultural Scenic Byway provides viewsheds along its southern spurs from Houma to

Cocodrie along LA 56 and then to Dulac on LA 57.

Forested Wetlands

This zone is within the Inland Swamps ecoregion. The terrain is mostly bottomland

hardwood and Bald Cypress communities. Water resources include Lake Palourde in the

area north of Morgan City and numerous canals in the area south of Houma. Man made

features include petroleum and natural gas wells and the Houma Navigation Canal. Lake

End Park provides visual access to Lake Palourde. LA 315 and LA 57 provide viewsheds

to the area south of Houma as one travels to Theriot and Dulac. Physical access to most

of the area is limited to boat travel. Viewsheds may be limited by the interspersed

pockets of forest vegetation.

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Visual Resource Inventory

The following visual resources’ scenic character has been recognized by national or state

designations. There may be additional visual resources not identified including public

parks and recreation areas. These types of resources were not acknowledged in the

public scoping for the LCA study. Specific project details used for the resources’

environmental impact analysis may identify other visual resources.

Houma Historic District

The Houma Historic District consists of the city's central business district and two related

residential areas including 118 buildings. The Houma Historic District Terrebonne

Parish Courthouse Square surrounded by mature live oak trees is the historic district

center. Most of the commercial buildings are located along Main Street, which parallels

Bayou Terrebonne. In its central portions, Main Street has a two-story scale consisting

mainly of typical early-twentieth century commercial buildings with commercial space

downstairs and residential space above. Historic residences of the district are primarily

shotgun houses, bungalows, or cottages (see Figure 4.9).

Morgan City Historic District

The Morgan City Historic District encompasses eighty-two commercial, residential, and

institutional buildings set on all or part of eight blocks. The town has a grid street

pattern. Most of the larger commercial buildings face the seawall along Front Street, but

there are several along Railroad Avenue as well. The commercial area has a mixed oneand two-story scale. A visual focus of the town is the city hall with its twin Italianate

tower cupolas which are visible for several blocks. Residences are located primarily on

First and Second Streets. As in most other towns, Morgan City's residences are set back

from the street while its commercial buildings are set directly behind the sidewalk (see

Figure 4.9).

Mandalay National Wildlife Refuge

Mandalay National Wildlife Refuge is located approximately 6 miles southwest of

Houma, Louisiana. Access to the interior is limited to boat travel. The 4,416-acre refuge

is a stopping point for migratory birds. Recreation use includes wildlife observation and

photography. The refuge also provides opportunities for environmental education and

interpretation.

Pointe Au Chien Wildlife Management Area

Pointe Au Chien Wildlife Management Area is approximately 15 miles southeast of

Houma. This area includes approximately 35,000 acres. Access to the interior is limited

to boat travel. The only timber stands are located on the Point Farm Unit of the area, or

areas adjacent to natural bayous and older oil and gas canals. Recreation use includes

nature study, camping, and picnicking.

Wetlands Cultural Scenic Byway

The Wetlands Cultural Scenic Byway is 204.1 miles in length and has two interconnected

loops and three spurs. The spurs are primarily contained within the study area. The

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eastern spur extends along LA 182 from between Houma and Gibson allowing access to

Houma’s Downtown National Historic District and Mandalay National Wildlife Refuge.

Two southern spurs descend from Houma to Cocodrie along LA 56 with a side route on

LA 57 to Dulac. These route segments are shown in Figure 4.9.

4.2.14 Recreation

This resource is institutionally significant because of the Federal Water Project

Recreation Act of 1965, as amended, and the Land and Water Conservation Fund Act of

1965, as amended. Recreational resources are technically significant because of the high

economic value of recreational activities and their contribution to local, state, and

national economies. Recreational resources are publicly significant because of the high

value that the public places on fishing, hunting, and boating, as measured by the large

number of fishing and hunting licenses sold in Louisiana, and the large per-capita number

of recreational boat registrations in Louisiana (Tables 4.13 through 4.15).

4.2.14.1 Historic and Existing Conditions

The study area is comprised of a series of narrow ridges along bayous which extend

toward the Gulf of Mexico through coastal swamps and marshes. The more significant

ridges along navigable bayous have historically supported development of small

communities and provide key points of access to the vast coastal wetland resources of the

study area.

These extensive wetland resources, comprised of swamp and marsh habitat, have

traditionally supported substantial consumptive and non-consumptive recreation use.

Primary consumptive recreational uses have included both freshwater and saltwater based

activities. Freshwater based consumptive uses include freshwater fishing, crawfishing,

hunting for waterfowl, as well as hunting for deer or small game along natural ridges and

in wooded swamp lands. Primary saltwater based activities have included saltwater

fishing, recreational shrimping, and crabbing. Non-consumptive activities have included

recreational boating, water skiing, birdwatching, hiking, and camping.

Like much of coastal southeast Louisiana, the eastern and central sections of the study

area have experienced substantial coastal erosion, loss of wetlands, and increasing

salinity levels. These conditions are due to numerous factors, such as extensive oil and

gas exploration via a maze of canals and pipelines, subsidence, and coastal storm surges.

Although the study area has traditionally provided excellent saltwater fishing, in recent

years, because of the increased salinity levels, anglers have been able to catch saltwater

species much farther inland than in the past. As fresh and intermediate marshes, cypress

trees, and submerged aquatic vegetation in the area have disappeared, waterfowl habitat

has become less abundant, and, consequently, duck hunting opportunities have decreased.

Unlike most of coastal Louisiana, the far western portion of the study area, due to the

influence of the Atchafalaya River, has been relatively stable or experiencing some

limited accretion of deltaic lands. Salinity levels are relatively stable in this area and

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freshwater fishing opportunities in the area are excellent. The floating marshes

traditionally have provided quality habitat for waterfowl and waterfowl hunting.

The study area includes the 4,212-acre Mandalay National Wildlife Refuge (NWR) and

the 31,902-acre Pointe au Chien Wildlife Management Area (WMA). The Mandalay

NWR alone is visited annually more than two thousand times. The most prominent

recreational activities within the study area are: fishing and waterfowl hunting. Limited

consumptive recreation uses include recreational crabbing, shrimping, and crawfishing.

Natural ridges are also utilized for deer and small game hunting. Non-consumptive

recreational activities attract far fewer participants and include birdwatching at both

Mandalay and Pointe au Chien, hiking at Mandalay, and camping at Pointe au Chien.

Recreation resources are publicly significant because of the high value that the public

places on fishing, boating, and hunting as measured by the large number of fishing and

hunting licenses and the large number of recreational boat registrations obtained in area

Parishes. This is particularly important as many of the predominant recreational

activities in the study area are only accessible by boat. Thirty seven boat launches are

located in the study area and provide access to recreation opportunities.

Tables 4.13, 4.14, and 4.15 below show the number of fishing licenses, hunting licenses,

and boat registrations, respectively, within the study area. The fishing and hunting

license and boat registration data are provided by the Louisiana Department of Wildlife

and Fisheries (http://www.wlf.louisiana.gov/education/economics/).

Table 4.13. Fishing Licenses Sold in the Vicinity of Project Area- Fiscal Year 2008.

Parish ResidentFreshwater

Resident -

Saltwater

NonResident

Freshwater

NonResident

Saltwater

NonResident

Temporary

Terrebonne 27,820 27,834 5,523 5,403 832

Lafourche 23,422 22,979 6,155 5,993 992

St. Mary 9,634 8,432 1,195 747 122

Table 4.14. Boat Registrations in the Vicinity of the Project Area - Fiscal Year 2008.

Parish Boat Registrations

Terrebonne 14,437

Lafourche 11,582

St. Mary 7,667

Table 4.15. Hunting Licenses Sold in the Vicinity of the Project Area - Fiscal Year 2008.

Parish Resident Non-Resident Resident

Duck Only

Non-Resident

Duck Only

Terrebonne 8,720 352 2,816 261

Lafourche 8,149 73 2,235 20

St. Mary 4,484 110 827 47

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4.2.15 Socioeconomics and Human Resources

This resource is institutionally significant because of the National Environmental Policy

Act of 1969; the Estuary Protection Act; the Clean Water Act; the River and Harbors

Acts; the Watershed Protection and Flood Protection Act; and the Water Resources

Development Acts. Of particular relevance is the degree to which the proposed action

affects public health, safety, and economic well-being; and the quality of the human

environment. This resource is technically significant because the social and economic

welfare of the nation may be positively or adversely impacted by the proposed action.

This resource is publicly significant because of the public’s concern for health, welfare,

and economic and social well-being from water resources projects.

4.2.15.1 Population and Housing

4.2.15.1.1 Historic and Existing Conditions

The project area encompasses parts of five parishes: Assumption, Lafourche, St. Martin,

St. Mary, and Terrebonne. The total population of these five parishes in 2008 was

approximately 327,000. The total population of the five parishes is projected to grow to

approximately 339,000 by the year 2030. The study area itself, however, is smaller than

the multi-parish area and encompasses only portions of this population. The majority of

the residential population in the project area is located in Terrebonne, St. Mary, and

Lafourche Parishes. The major population centers in the project area are Morgan City

(St. Mary Parish) and Houma (Terrebonne Parish) whose populations in 2008 were

11,604 and 32,512, respectively (Table 4.16).

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 4.16. Parish and City Population and Housing Unit Estimates for 1940 to 2008.Location 1940 1950 1960 1970 1980 1990 2000 2001 2002 2003 2004 2005 2006 2007 2008Lafourche

Population 38,615 42,209 55,381 68,941 82,483 85,860 89,972 90,040 90,652 91,221 91,608 91,347 92,775 92,704 92,572

Housing Units 8,972 11,340 15,177 19,205 27,033 31,332 35,133 35,490 35,763 36,056 36,358 36,677 37,195 37,722 38,172

St. Mary

Population 31,458 35,848 48,833 60,752 64,253 58,086 53,258 52,526 52,179 51,883 51,526 50,855 51,614 51,286 51,083

Housing Units 8,015 10,360 13,538 17,279 21,539 21,884 21,690 21,849 21,942 22,058 22,144 22,241 22,459 22,580 22,718

Morgan City

Population

--- --- --- 16,586 16,114 14,531 12,620 12,340 12,184 12,150 12,001 11,802 11,872 11,726 11,604

Terrebonne

Population 35,880 43,328 60,771 76,049 94,393 96,982 104,455 104,724 104,912 105,157 105,435 106,167 108,043 108,316 108,576

Housing Units 8,573 11,239 15,862 20,854 30,831 35,416 40,048 40,525 40,975 41,427 42,092 42,581 43,354 43,995 44,320

Houma

Population --- --- --- 30,922 32,602 30,495 32,834 32,677 32,518 32,387 32,196 32,208 32,764 32,586 32,512

Source: U.S. Census Bureau, Department of Commerce.

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Table 4.17. Parish Population Projections.

Location 2010 2015 2020 2025 2030

Lafourche 93,740 95,160 95,990 96,310 95,990

St. Mary 49,400 47,410 45,230 42,870 40,390

Terrebonne 118,890 122,560 124,410 125,140 125,210

Source: Blanchard, T.C. 2009. Population Projections of Louisiana Parishes through

2030. Louisiana State University.

4.2.15.2 Employment and Income

4.2.15.2.1 Historic and Existing Conditions

Economic activities in the project area include the harvest of sugarcane, oil and gas

production, the transport of these resources, the construction and maintenance of oil rigs,

commercial fishing and markets supporting recreational fishing and hunting, and

commercial activities supporting the local communities. By far the most important crop

harvested has been sugarcane.

The area originally developed as a market center for fish, wildlife, and agricultural

production; however, with the discovery of oil and gas and the technology to extract

those from surrounding wetlands and water bottoms, employment and income

opportunities increased.

During the 1980s, however, the maturing of oil and gas industries, and its availability at

more competitive prices in other countries, caused severe unemployment and outmigration in the area. During the 1990s the continued availability of oil, water resources,

fish and wildlife for both commercial and recreational purposes, and national economic

trends, appear to have contributed to the area's gradual economic recovery.

Table 4.18 summarizes a recent estimate of the types and amounts of employment

occurring in Lafourche, St. Mary, and Terrebonne Parishes and compares it to

employment categories statewide. Table 4.19 summarizes per capita personal income in

the area and statewide.

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Table 4.18. 2007 Employment Characteristics. Number of individuals employed by industry

(percent by area in parentheses).

Employment by

Industry

Lafourche

Parish

St. Mary

Parish

Terrebonne

Parish

State

Farm 630 (1.1%) 364 (1.0%) 214 (0.3%) 34372 (1.4%)

Forestry, Fishing,

and related

2116 (3.5%) 384 (1.1%) 829 (1.3%) 20930 (0.8%)

Mining 1199 (2.0%) 1285 (3.7%) 5972 (9.3%) 61370 (2.4%)

Utilities 85 (0.1%) 71 (0.2%) 126 (0.2%) 9655 (0.4%)

Construction 5766 (9.7%) 3504 (10.1%) 4333 (6.8%) 208969 (8.3%)

Manufacturing 3711 (6.2%) 4774 (13.7%) 7346 (11.5%) 165312 (6.6%)

Wholesale Trade 915 (1.5%) 1002 (2.9%) 2185 (3.4%) 83161 (3.3%)

Retail Trade 5291 (8.9%) 2941 (8.5%) 8029 (12.5%) 274233

(10.9%)

Transportation

and Warehousing

8203 (13.7%) 3466 (10.0%) 3251 (5.1%) 95037 (3.8%)

Information 380 (0.6%) 215 (0.6%) 461 (0.7%) 32915 (1.3%)

Finance and

Insurance

1722 (2.9%) 771 (2.2%) 1388 (2.2%) 86037 (3.4%)

Real Estate 3387 (5.7%) 1465 (4.2%) 2335 (3.6%) 85985 (3.4%)

Professional,

Scientific,

Technical

2267 (3.8%) 921 (2.6%) 1767 (2.8%) 132025 (5.2%)

Management 1053 (1.8%) 54 (0.2%) 407 (0.6%) 24575 (1.0%)

Admin and Waste

Services

4139 (6.9%) 2049 (5.9%) 3730 (5.8%) 145532 (5.8%)

Education 651 (1.1%) * 416 (0.6%) 41896 (1.7%)

Health Care 3591 (6.0%) * 5603 (8.7%) 252607

(10.0%)

Entertainment 901 (1.5%) 478 (1.4%) 446 (0.7%) 49534 (2.0%)

Accommodation

and Food Services

2643 (4.4%) 1850 (5.3%) 4727 (7.4%) 173706 (6.9%)

Other Services 3583 (6.0%) 1794 (5.2%) 3430 (5.4%) 147555 (5.9%)

Government 7437 (12.5%) 5492 (15.8%) 7094 (11.1%) 391679

(15.6%)

Totals 59670 34781 64089 2517085

* Confidential Information

Source: Regional Economic Information System, Bureau of Economic Analysis, US

Department of Commerce

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 4.19. Per Capita Personal Income from 1970 to 2007 (not adjusted for inflation).

Area 1970 1980 1990 2000 2001 2002 2003 2004 2005 2006 2007

LafourcheParish

$2,792 $9,190 $13,059 $22,539 $25,210 $25,678 $26,360 $26,957 $28,340 $33,410 $37,257

St. MaryParish

$2,888 $8,826 $12,725 $21,085 $23,543 $24,106 $25,197 $25,881 $27,455 $32,748 $35,328

TerrebonneParish

$2,915 $9,582 $13,190 $20,781 $22,502 $23,191 $23,751 $24,814 $25,454 $31,588 $34,744

State $3,090 $8,777 $15,173 $23,082 $24,719 $25,249 $25,862 $27,262 $24,651 $32,832 $35,100Source: Regional Economic Information System, Bureau of Economic Analysis, US Department of Commerce

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4.2.15.3 Infrastructure

4.2.15.3.1 Business and Industry

4.2.15.3.1.1 Historic and Existing Conditions

Major business and industry in and around the project area includes oil and gas

exploration and production, commercial fishing and seafood processing, agriculture and

sugar mills, carbon black plants, shipbuilders, fabrication firms, tourism, and salt mining.

Table 4.18 contains information on employment by industry group in Lafourche, St.

Mary, and Terrebonne Parishes, and statewide.

4.2.15.3.2 Transportation

4.2.15.3.2.1 Historic and Existing Conditions

The transportation infrastructure of the study area includes major roadways and navigable

waterways. U.S. Route 90 passes through the project area and connects Morgan City and

Houma with Lafayette to the west and New Orleans to the East. Four state highways

connect Houma with the southern portions of the project area. Navigation in the vicinity

includes the movement of oil and gas supply vessels, commercial fishing vessels,

pleasure crafts, and other barge traffic along the Atchafalaya River, the HNC, the GIWW,

Bayous Chene, Boeuf, and Black, and other lesser waterways. The GIWW extends from

the Mexican border to Appalachee Bay in Florida. The HNC is maintained for

approximately 40.5 miles, from Houma to Terrebonne Bay, leading to the open Gulf of

Mexico. See Section 4.2.15.6 for further information on Navigation.

4.2.15.3.3 Public Facilities and Services

4.2.15.3.3.1 Historic and Existing Conditions

Public and quasi-public facilities and services in the project area include schools,

hospitals, police and fire protection, an extensive network of pumps and levees for flood

protection, and a series of navigation canals, including the Atchafalaya River, the Houma

Navigation Canal, and the Gulf Intracoastal Waterway. During the threat of hurricanes

and severe flooding, public buildings are occasionally used as temporary shelter for

residents who are impacted.

4.2.15.3.4 Tax Revenue and Property Values

4.2.15.3.4.1 Historic and Existing Conditions

Tax revenue and property values in Terrebonne Parish and Lafourche Parish appear to be

almost identical, while Morgan City in St. Mary Parish has a lower median income and

home value. Parish per capita income trends can be found in Table 4.19. Terrebonne

Parish median household income in 2008 was $51,023. This was up from $35,235 in

1999. The median home value in 2008 was $121,400, up from $72,200 in 2000.

Lafourche Parish median household income in 2008 was $51,227, an increase from

$34,910 in 1999. The median home value in 2008 was $122,800, up from $71,100 in

2000. Morgan City median household income in 2008 was $37,491. This was up from

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$28,324 in 2000. Median home value in 2008 was $125,750, an increase from $71,900 in

2000. All information from this section was obtained from city-data.com, accessed

February 1, 2010.

4.2.15.3.5 Community and Regional Growth (including Community Cohesion)

4.2.15.3.5.1 Historic and Existing Conditions

Community cohesion is defined as the unifying force of a group due to one or more

characteristics that provide commonality. These characteristics may include such

commonality as race, education, income, ethnicity, religion, language, and mutual

economic and social benefits. Community cohesion is the force that keeps group

members together long enough to establish meaningful interactions, common institutions,

and agreed upon ways of behavior. It is a dynamic process, changing as the physical and

human environment changes. The changes brought about by water resource development

can impact community cohesion in different ways. For example, changing a channel

location may divide a community; it may cause the dislocation of a significant number of

residents or it may require the relocation of an important local institution, such as a

church or community center. Loss of coastal resources traditionally utilized by local

communities can similarly have a negative impact on community cohesion. Conversely,

water resource development such as increasing or improving coastal marsh habitat can

represent an important public works project heavily supported by the local community.

Historic growth trends in the project area (Table 4.16) show steady growth in Lafourche,

St. Mary, and Terrebonne Parishes from the 1940s to the 1990s. Since 1990, St. Mary

Parish population has been slowly on the decline. Growth trends in Lafourche and

Terrebonne parishes continued, but at a slower pace. Current population projections

(Table 4.17) predict declining populations in St. Mary Parish and slowly increasing

populations in Lafourche and Terrebonne Parishes (Blanchard 2009).

4.2.15.4 Environmental Justice

Environmental Justice (EJ) is institutionally significant because of Executive Order

12898 of 1994 (E.O. 12898) and the Department of Defense’s Strategy on Environmental

Justice of 1995, which direct Federal agencies to identify and address any

disproportionately high adverse human health or environmental effects of Federal actions

to minority and/or low-income populations. Minority populations are those persons who

identify themselves as Black, Hispanic, Asian American, American Indian/Alaskan

Native, and Pacific Islander. A minority population exists where the percentage of

minorities in an affected area either exceeds 50 percent or is meaningfully greater than in

the general population. Low-income populations as of 2000 are those whose income is

below $22,050 for a family of four and are identified using the Census Bureau’s

statistical poverty threshold. The Census Bureau defines a “poverty area” as a Census

tract with 20 percent or more of its residents below the poverty threshold and an “extreme

poverty area” as one with 40 percent or more below the poverty level. This is updated

annually at http://aspe.hhs.gov/poverty/09poverty.shtml. This resource is technically

significant because the social and economic welfare of minority and low-income

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populations may be positively or disproportionately impacted by the proposed actions.

This resource is publicly significant because of public concerns about the fair and

equitable treatment (fair treatment and meaningful involvement) of all people with

respect to environmental and human health consequences of federal laws, regulations,

policies, and actions.

A potential disproportionate impact may occur when the percent minority (50 percent)

and/or percent low-income (20 percent) population in an EJ study area are greater than

those in the reference community. For purposes of this analysis, all Census Designated

Properties (CDP), that is, cities and towns in designated census areas with small

populations, in three sub areas of the project footprint are defined as the EJ study area.

Terrebonne and Lafourche Parishes are considered the reference community of

comparison and whose population is therefore considered the EJ reference population for

comparison purposes. Parish figures were used for unincorporated areas located within

one mile of the proposed project footprint.

The methodology, consistent with E.O. 12898, to accomplish this Environmental Justice

analysis includes identifying low-income and minority populations within the project area

using up-to-date economic statistics, aerial photographs, 2000 U.S. Census records,

Environmental Systems Research Institute, Inc. (ESRI) estimates, as well as conducting

community outreach activities such as public meetings. Despite the 2000 U.S. Census

being nine years old, it serves as a logical baseline of information and is the primary

deciding variable per data accuracy and reliability for the following reasons:

• Census 2000 data is the most accurate source of data available due to the sample

size of the Census decennial surveys. With one of every six households surveyed,

the margin of error is negligible.

• The Census reports data at a much smaller geographic level than other survey

sources, providing a more defined and versatile option for data reporting.

• Census information sheds light upon the demographic and economic framework

of the area pre-Hurricane Katrina. By accounting for the absent population, the

analysis does not exclude potentially low income and minority families that wish

to return home.

Due to the considerable impact of Hurricane Katrina upon the New Orleans metropolitan

area, and the likely shift in demographics and income, the 2000 Census data are

supplemented with more current data, including 2007 and 2008 estimates provided by

ESRI. The 2007 and 2008 estimates are utilized for reference purposes only to show

changing trends in population since 2000.

4.2.15.4.1 Historic and Existing Conditions

The concept of “environmental justice” is rooted in Title VI of the Civil Rights Act of

1964, which prohibited discrimination based on race, color and national origin, and other

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nondiscrimination statutes as well as other statutes including the National Environmental

Policy Act of 1969, the Uniform Relocations Assistance and Real Property Acquisition

Policies Act of 1970, and 23 U.S.C Section 109 (h). In 1971, the Council on

Environmental Quality’s (CEQ) annual report acknowledged racial discrimination

adversely affects the environment of the urban poor. During the next ten years, activists

maintained that toxic waste sites were disproportionately located in low-income areas and

areas populated by “people of color.” By the early 1980s, the environmental justice

movement had increased its visibility and broadened its support base (Commission for

Environmental Equality 2009).

This led to the United Church of Christ (UCC) undertaking a nationwide study and

publishing Toxic Waste and Race in the United States (UCC 1987). This eventually

gained the attention of the federal government and in 1992 the U.S. Environmental

Protection Agency’s (EPA’s) Office of Environmental Equity was established. In 1994,

EJ was institutionalized within the federal government through Executive Order 12898

(EPA 1995a), which focused federal attention on human-health and environmental

conditions in minority and low-income communities (EPA 1995a, 1995b, 1995c, 1995d).

Executive Order 12898 requires greater public participation and access to environmental

information in affected communities. The results of early efforts and research (UCC

1987) into EJ suggested that environmental amenities and toxic waste sites were not

uniformly distributed among income groups, classes, or ethnic communities. Disparities

of this nature may have been and continue to be the result of historical circumstances,

lack of community participation, or simply inadequate or inappropriate oversight.

Consequently, dialogue with some community groups were not conducted and their

concerns not considered in the decision-making process on local or federal actions.

The proposed project area is located in Terrebonne and Lafourche Parishes in Louisiana.

The total population of these two parishes, according to the U.S. Census Bureau’s 2008

estimates, is 200,996. This figure reflects a more than 1 percent increase in population

since 2000, with the projected increased population distribution occurring in both

parishes. For analysis purposes, the project discussion of impacts will be broken into

three project sub-areas: West-Bayou Penchant, Central-Lake Boudreaux, and East-Grand

Bayou Areas.

According to the 2000 U.S. Census, the demographic profile records indicate that the

minority population in Louisiana was 38.7 percent of the total population and the lowincome population was 19.6 percent of the total population. In comparison, the minority

population in Terrebonne Parish was 27.9 percent and the low-income population was

19.1 percent. For Lafourche Parish, the 2000 U.S. Census demographic profile records

indicate that the minority population was 18.8 percent and the low-income population

was 16.5 percent. The 2008 U.S. Census projections indicate that the minority

population in Terrebonne Parish increased to approximately 30.2 percent minority and

the low-income population decreased to 16.5 percent. For Lafourche Parish, the 2008

projections show the minority population increasing to 20.5 percent and the low-income

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population remained the same at 16.5 percent (http://censtats.census.gov., accessed

December 11, 2009).

Analyses of the above information show that the percentage of the population that is

minority and low-income in Terrebonne and Lafourche Parishes are lower than state

figures. Based on these figures it has been determined that the proposed project area is

not a minority and low income population. Thus there are no potential concerns for

Environmental Justice per Executive Order 12898.

The cities located within the West-Bayou Penchant Area are: Morgan City, Berwick and

Amelia. As of 2000 the U.S. Census estimates that Morgan City had a 32.5 percent

minority and a 20.7 percent low-income population. In 2000, Berwick had a 15 percent

minority and a 14.8 percent low-income population. Amelia had a 49.7 percent minority

population and a 32.5 percent low-income population (

West-Bayou Penchant Area

http://censtats.census.gov.,

accessed December 14, 2009).

The cities located in the Central-Lake Boudreaux area are: Montegut, Chauvin and Dulac.

As of the 2000 U.S. Census, the minority population in Montegut was 14.6 percent

minority and 22.9 percent low-income. In Chauvin, the minority population was 3.7

percent and 20.1 percent low-income; and in Dulac, the minority population was 48.7

percent and 30.9 percent low-income (

Central-Lake Boudreaux Area

http://censtats.census.gov., accessed December 11,

2009).

The cities located in the East-Grand Bayou area are: Larose, Cut Off and Galliano. As of

the 2000 U.S. Census, the minority population in Larose was 17.3 percent minority and

15.5 percent low-income. In Cut Off, the minority population was 10.9 percent and 7.9

percent low-income; and in Galliano, the minority population was 9.7 percent and 15.9

percent low-income population (

East-Grand Bayou Area

http://censtats.census.gov., accessed December 11,

2009).

These figures indicate that minority and/or low income populations exist throughout the

study area.

4.2.15.5 Water Use and Supply

4.2.15.5.1 Historic and Existing Conditions

The LDEQ assesses seven categories for water use under the Louisiana Environmental

Regulatory Code (LAC Title 33, Chapter 11) that would apply to the project area.

Primary Contact Recreation includes activities such as swimming, water skiing, tubing,

snorkeling, skin diving, and other activities that involve prolonged body contact with

water and probable ingestion. Secondary Contact Recreation includes fishing, wading,

and recreational boating, and other activities that involve only incidental or accidental

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body contact and minimal probability of ingesting water. Fish and Wildlife Propagation

includes the use of water by aquatic biota for aquatic habitat, food, resting reproduction,

and cover, including indigenous fishes and invertebrates, reptiles, amphibians, and other

aquatic biota consumed by humans. Drinking water supply refers to the use of water for

human consumption and general household use. Oyster Propagation includes the use of

water to maintain biological systems that support economically important species of

oysters, clams, mussels, and other mollusks consumed by humans so that their

productivity is preserved and the health of human consumers of these species is

protected. Agriculture includes the use of water for crop spraying, irrigation, livestock

watering, poultry operations, and other farm purposes not related to human consumption.

Outstanding natural resource waters are water bodies designated for preservation,

protection, reclamation, or enhancement of wilderness, aesthetic qualities, and ecological

regimes, such as those designated under the Louisiana Natural and Scenic Rivers System

or those designated by the department as waters of ecological significance.

Streams within the project area and their designated uses as identified in the Louisiana

Environmental Regulatory Code (LAC Title 33, Chapter 11) are listed in Table 4.20.

Table 4.20. Designated Uses for Streams within the Project Area (LAC Title 33, Chapter 11).

Code Stream Description Designated

Uses

Atchafalaya River Basin (01)

10801 Atchafalaya River–From ICWW south of Morgan City to Atchafalaya

Bay; includes Sweetwater Lake and Bayou Shaffer ABC

10803 Intracoastal Waterway–From Bayou Boeuf Lock to Bayou Sale;

includes Wax Lake Outlet to US-90 ABC

Terrebonne Basin (12)

120202 Bayou Black–From ICWW to Houma ABCD

120203 Bayou Boeuf–From Lake Palourde to ICWW ABCD

120205 Lake Palourde ABCD

120304 Intracoastal Waterway–From Houma to Larose ABCDF

120401 Bayou Penchant–From Bayou Chene to Lake Penchant ABCG

120402 Bayou Chene–From ICWW to Bayou Penchant ABC

120403 Intracoastal Waterway–From Bayou Boeuf Locks to Bayou Black in

Houma; includes segments of Bayous Boeuf, Black, and Chene ABCDF

120404 Lake Penchant ABC

120405 Lake Hache and Lake Theriot ABC

120406 Lake de Cade ABCE

120501 Bayou Grand Caillou–From Houma to Bayou Pelton ABC

120502 Bayou Grand Caillou–From Bayou Pelton to Houma Navigation Canal

(Estuarine) ABCE

120503 Bayou Petit Caillou–From Bayou Terrebonne to LA-24 bridge ABCE

120504 Bayou Petit Caillou–From LA-24 bridge to Boudreaux Canal

(Estuarine) ABCE

120505 Bayou Du Large–From Houma to Marmande Canal ABC

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Code Stream Description Designated

Uses

120506 Bayou Du Large–From Marmande Canal to one-half mile north of St.

Andrews Mission (Estuarine)

ABCE

120507 Bayou Chauvin–From Ashland Canal to Lake Boudreaux (Estuarine) ABC

120508 Houma Navigation Canal–From Bayou Pelton to one mile south of

Bayou Grand Caillou (Estuarine) ABCE

120509 Houma Navigation Canal–From Houma to Bayou Pelton ABCD

120601 Bayou Terrebonne–From Houma to Company Canal (Estuarine) ABC

120602 Bayou Terrebonne–From Company Canal to Humble Canal

(Estuarine) ABCE

120603 Company Canal–From ICWW to Bayou Terrebonne ABC

120604 Bayou Blue–From ICWW to Grand Bayou Canal ABC

120605 Bayou Pointe Au Chien–From headwaters to St. Louis Canal ABC

120606 Bayou Blue–From Grand Bayou Canal to Bully Camp Canal

(Estuarine) ABC

120701 Bayou Grand Caillou–From Houma Navigation Canal to Caillou Bay

(Estuarine) ABCE

120702 Bayou Petit Caillou–From Boudreaux Canal to Houma Navigation

Canal (Estuarine) ABCE

120703 Bayou Du Large–From one-half mile north of St. Andrews Mission to

Caillou Bay (Estuarine) ABCE

120704 Bayou Terrebonne–From Humble Canal to Lake Barre (Estuarine) ABCE

120705 Houma Navigation Canal–From one-half mile south of Bayou Grand

Caillou to Terrebonne Bay (Estuarine) ABCE

120706 Bayou Blue–From Bully Camp Canal to Lake Raccourci (Estuarine) A B C E

120707 Lake Boudreaux ABCE

A-Primary Contact Recreation; B-Secondary Contact Recreation; C-Fish And Wildlife

Propagation; D-Drinking Water Supply; E-Oyster Propagation; F-Agriculture; G-Outstanding

Natural Resource Waters

4.2.15.6 Navigation

4.2.15.6.1 Historic and Existing Conditions

Major navigation corridors in the study area include the GIWW, the Lower Atchafalaya

River, Bayous Chene, Boeuf, and Black, and the Houma Navigation Canal. Navigation

channels are also maintained on Bayou Grand Caillou, Bayou Petit Caillou, and Bayou

Terrebonne. Just outside of the project area, Bayou Lafourche is used extensively as a

route to Port Fourchon. Navigation in the vicinity includes the movement of oil and gas

supply vessels, commercial fishing vessels, pleasure crafts, and other barge traffic.

Primary cargos include petroleum, petroleum products, sugar, crude materials, chemicals,

and manufactured goods (Table 4.21).

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Commodity Lower

Atchafalaya

Bayou Boeuf

Lock

HNC Bayou

Lafourche

Bayou

Grand

Caillou

Bayou Petit

Caillou

Bayou

Terrebonne

Coal and Coal

Products

0.0 458.2 0.0 0.0 0.0 0.0 0.0

Petroleum and

Petroleum Products

888.9 13,276.1 620.8 1,196.3 49.4 183.5 11.0

Chemicals 0.3 3,681.7 0.0 86.1 0.7 0.0 0.0

Crude Materials 92.1 5,317.9 205.2 654.6 14.6 38.8 193.0

Manufactured

Goods

10.7 1,675.4 4.7 91.0 5.2 0.5 0.5

Food and Farm

Products

237.8 536.1 0.0 371.6 0.0 0.0 0.5

Manufactured

Equipment

49.7 455.1 13.6 3,469.0 3.1 1.5 10.0

Waste Material 1.5 822.8 0.0 259.9 0.0 0.0 0.0

Other Cargo 2.9 22.0 0.0 0.5 0.0 0.0 0.0

Total Cargo 1,283.9 26,245.3 844.3 6,129.0 73.0 224.3 215.1

Number of Vessels 37,294 21,372 9,338 49,270 5,079 3,339 2,167

Source: Waterborne Commerce Statistics Center; www.iwr.usace.army.mil/ndc/wcsc/wcsc.htm; accessed 11 December 2009.

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4.2.15.7 Land Use Socioeconomics

4.2.15.7.1 Agriculture

4.2.15.7.1.1 Historic and Existing Conditions

Agriculture is an important component of coastal Louisiana’s economy. More than $5.3

billion of crops and livestock were produced in Coastal Louisiana in 2008. The rich

deltaic soil and mild climate are conducive to the production of a wide variety of crops,

including sugar cane, rice, and soybeans. Approximately 20 percent of the Nation’s rice

and 37 percent of the Nation’s sugar are produced in Louisiana. Most of this production

is in the coastal areas of the state and many of these areas are experiencing either direct

land loss or increasing salinities of waters that are used for crop irrigation.

Crop production in and around the study area is dominated by sugar cane. Significant

income is also derived from livestock production, primarily cattle and horses, and from

aquaculture, primarily alligators and crawfish (Table 4.22). In the sugar producing areas,

production has been hampered by subsidence resulting in flooding and drainage

problems. Even in areas where saltwater intrusion has not occurred, the loss of adjacent

wetlands makes croplands more susceptible to storm damages.

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Table 4.22. 2008 Crop and Livestock Production in the Vicinity of the Project Area and in Louisiana

(in millions of dollars).

Sugarcane Crawfish Alligators Cattle Horses

Lafourche

Parish

$22.7 $4.0 $5.4 $9.8 $1.1

St. Mary

Parish

$34.7 --- --- $2.1 $1.1

Terrebonne

Parish

$8.9 $0.3 $3.3 $0.9 $1.0

State

Total

$357.6 $121.3 $33.4 $343.3 $510.9

Source: Louisiana State University AgCenter; lsuagcenter.com; accessed 12 January

2010.

4.2.15.7.2 Forestry

4.2.15.7.2.1 Historic and Existing Conditions

Timber production in Louisiana’s forested wetlands is an important renewable resource.

The value of sawtimber, pulpwood, and chip-n-saw products for landowners in Louisiana

in 2008 totaled $470 million (LDAF 2009). Standing timber values in Lafourche, St.

Mary, and Terrebonne Parishes totaled $207 thousand, $3 thousand, and $118 thousand,

respectively, in 2008. Standing timber values in the vicinity of the project area and the

state from 1970 to 2008 can be found in Table 4.23. In addition to standing timber values

for landowners, forestry-related employment is an important socioeconomic resource for

Louisiana. According to the U.S. Department of Commerce’s Regional Economic

Information System, the forestry and logging industry accounted for $240 million of

personal income in the state of Louisiana in 2007. In Lafourche, St. Mary, and

Terrebonne Parishes, forestry and logging accounted for $611 thousand, $1.4 million, and

$246 thousand of personal income, respectively, in 2007.

Table 4.23. Standing Timber Values in the Vicinity of the Project Area and in Louisiana.

1970 1980 1990 2000 2008

Lafourche

Parish

$55,590 $44,595 $63,180 $27,800 $207,170

St. Mary

Parish

$8,279 $58,621 $2,235 $73,254 $3,428

Terrebonne

Parish

$55,583 $42,854 $1,501 $3,769 $118,130

State

Total

$53,973,234 $218,398,232 $338,864,145 $654,769,596 $471,227,081

Source: Louisiana Department of Agriculture and Forestry, Louisiana Timber and

Pulpwood Production Reports, 1970-2008.

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4.2.15.7.3 Public Lands

This resource is institutionally significant because of the Federal Water Project

Recreation Act of 1965, as amended; the Land and Water Conservation Fund Act of

1965, as amended; the National Wildlife Refuge System Administration Act of 1966; and

the National Wildlife Refuge System Improvement Act of 1997. Public lands are

technically significant because of the high economic value of recreational activities and

their contribution to local, state, and national economies. Public lands are publicly

significant because of the high value that the public places on conservation of natural

resources, as well as access for fishing, hunting, and boating activities, as measured by

the large number of fishing and hunting licenses sold in Louisiana, and the large percapita number of recreational boat registrations in Louisiana.

4.2.15.7.3.1 Historic and Existing Conditions

Public lands are those areas owned by the Federal or state government, which have been

made available for public access. The National Wildlife Refuge System Improvement

Act of 1997 authorized that no new or expanded use of a refuge may be allowed unless it

is first determined to be a compatible use and the use is not inconsistent with public

safety.

In the eastern portion of the study area, the Louisiana Department of Wildlife and

Fisheries operates the 33,488-acre Pointe au Chien Wildlife Management Area about 15

miles southeast of Houma in Terrebonne and Lafourche Parishes. The habitat of the area

is mostly marsh, varying from nearly fresh to brackish interspersed with numerous ponds,

bayous, and canals. Game species hunted are waterfowl, deer, rabbit, squirrels, rail,

gallinule, and snipe. Inland saltwater fish species, crabs, and shrimp are available in the

more brackish water. Non-consumptive forms of recreation are boating, nature study,

undeveloped camping and picnicking. Management and water control has been practiced

on the area since its inception in 1968.

Southwest of Houma, near Lake Hatch, the USFWS manages the 4,212-acre Mandalay

National Wildlife Refuge. The habitat of the Refuge is mostly fresh marsh and is only

accessible by boat. The property is intersected by the GIWW. Hunting opportunities

include waterfowl, white-tailed deer, and feral hogs. Fishing, wildlife observation,

photography, and boating are also available on the refuge

4.2.15.8 Man Made Resources

4.2.15.8.1 Oil Gas and Utilities

4.2.15.8.1.1 Historic and Existing Conditions

The petroleum industry in the state accounts for almost 25 percent of the total state

revenues and employs more than 116,000 people (about 6 percent of the state’s total

workforce). These workers earn almost 12 percent of the total wages paid in Louisiana.

Indirect employment levels in support industries make this economic sector more

important than is indicated by the direct employment figures.

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The oil and gas production industry, and the numerous associated support industries, are

an important part of the socioeconomic landscape of the project area (see Employment

and Income section). Oil and gas infrastructure is prevalent throughout the study area

and vicinity (Figure 4.10).

The impacts of the Deepwater Horizon oil spill on coastal Louisiana are uncertain at this

time (August 2010). The impacts of the oil spill as well as the various emergency actions

taken to address oil spill impacts (e.g., use of oil dispersants, creation of sand berms, use

of Hesco baskets, rip-rap, sheet piling and other actions) could potentially impact

USACE water resources projects and studies within the Louisiana coastal area, including

the LCA-ARTM project. Potential impacts could include factors such as changes to

existing, future-without, and future-with-project conditions, as well as increased project

costs and implementation delays. The USACE will continue to monitor and closely

coordinate with other Federal and state resource agencies and local sponsors in

determining how to best address any potential problems associated with the oil spill that

may adversely impact project implementation. Supplemental planning and

environmental documentation may be required as information becomes available. If at

any time petroleum or crude oil is discovered on project lands, all efforts will be taken to

seek clean up by the responsible parties, pursuant to the Oil Pollution Act of 1990 (33

U.S.C. 2701 et seq.).

Ongoing documentation of the impacts associated with the Deepwater Horizon Oil spill

can be found in several governmental sources. The USFWS Situation Report for August

2, 2010 (http://www.fws.gov/home/dhoilspill/pdfs/MondayAugust22010.pdf) indicates

the following environmental-related Deepwater Horizon oil spill information: 563

personnel are actively engaged in the response, working to protect wildlife and their

habitats, including 36 national wildlife refuges. They are also assessing the damage from

the oil spill in preparation for the work that will be needed to restore the Gulf of Mexico.

Some 1,643 visibly oiled birds have been collected alive by the U.S. Fish and Wildlife

Service, the states and our partners in response to the Deepwater Horizon oil spill. Of

those, 594 birds have been rehabilitated and released. Another 1,451 visibly oiled birds

have been collected dead. Aerial operations over Louisiana observed an oil sheen

covering 300 acres in the northeastern portion of Barataria Bay. A heavily oiled coastline

covering about one-half mile was found at Bayou Chalond and heavy oil and tar balls

were observed on landfall east of Point-Au-Fer and along Timbalier Island. Beached bird

surveys were conducted in Texas, Louisiana, Mississippi, Alabama and Florida. Aerial

missions are scheduled for Southwest Pass, Chandeleur Islands, Biloxi Marsh, Barataria

Bay, Terrebonne, Marsh Islands, Atchafalaya Delta, Point-Au-Fer and Timbalier Bay.

• Overall number of personnel responding: approximately 30,100

• Total vessels responding: more than 4,500

• Total boom deployed: more than 2,155 miles

• Boom available: more than 856 miles

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• Oily water recovered: more than 34.7 million gallons

• Estimated 11.14 million gallons of oil burned

• Estimated total of more than 1.84 million gallons of dispersant used including:

o Estimated more than 1.07 million gallons surface dispersant used

o Estimated more than 771,000 gallons of sub-sea dispersant used

• Estimated approximately 632 miles of Gulf Coast shoreline is currently oiled—

approximately 365 miles in Louisiana, 111 miles in Mississippi, 68 miles in

Alabama, and 88 miles in Florida.

The USACE, New Orleans District Regulatory Branch has considered and responded to

approximately 55 emergency permits related to the Deepwater Horizon oil spill (see

Table 1.2). Emergency permits have the following clause that provides for removing,

relocating or altering permitted structures if necessary and upon due notice from the

Corps. The clause would pertain to future actions by the United States, such as proposed

Louisiana Coastal Area restoration projects:

The permittee understands and agrees that, if future operations by the United

States require the removal, relocation, or other alteration, of the structure or

work herein authorized, or if, in the opinion of the Secretary of the Army or his

authorized representative, said structure or work shall cause unreasonable

obstruction to the free navigation of the navigable waters, the permittee shall be

required upon due notice from the Corps of Engineers, to remove, relocate, or

alter the structural work or obstructions caused thereby, without expense to the

United States. No claim shall be made against the United States on account of any

such removal or alteration.

As is evident from the numerous ongoing actions, the dynamic nature of the impacts

associated with the Deepwater Horizon oil spill will likely require additional

consideration in the near future for USACE Civil Works projects.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.10. Oil and Gas Infrastructure in the Project Area.

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4.2.15.8.2 Flood Control and Hurricane Protection

4.2.15.8.2.1 Historic and Existing Conditions

There are several Federal flood control and hurricane protection levees in and around the

project area in addition to many local levees (Figure 4.11). Information on Federal flood

control and hurricane protection levees follows.

East Atchafalaya Basin Protection Levee (EABPL). This levee begins at the lower

end of the east guide levee of the Morganza Floodway, extends southward to and through

Morgan City to the Avoca Island Cutoff, and includes the Bayou Boeuf and Bayou Sorrel

locks. The length of this system is 106.7 miles, including 1.3 miles of floodwall along

the Morgan City front and about 0.4 miles of floodwall below Morgan City. The

Atchafalaya Basin Levee District and the city of Morgan City are responsible for

operation and maintenance of this feature.

West Atchafalaya Basin Protection Levee (WABPL). This levee begins near the town

of Hamburg, where it joins the Bayou des Glaises fuseplug levee. It extends in a south

and southeasterly direction to the Wax Lake Outlet at the latitude of the East and West

Calumet Floodgates and then eastward through Berwick to the Gulf Intracoastal

Waterway. This levee extends 128.7 miles and connects with 3 miles of floodwall along

the front of the town of Berwick.

Bayou Boeuf Lock. This lock is located in the EABPL below Morgan City at a point

where it crosses Bayou Boeuf and the Gulf Intracoastal Waterway. The lock has a length

of 1,136 feet, a clear width of 75 feet, and a depth over sills of 13 feet at NGVD. The

Bayou Boeuf Lock provides for navigation through the levee, which protects the areas

and communities east of Morgan City from floodwaters from the Atchafalaya Basin. It

was completed in 1955. It is operated and maintained by the U.S. Army Corps of

Engineers.

Larose to Golden Meadow Hurricane Protection Project. This project consists of a

ring levee approximately 40 miles in length protecting the areas along the east and west

banks of Bayou Lafourche, extending from Larose to just south of Golden Meadow.

Floodwalls were constructed in areas where the congested nature of improvements and

limited right-of-way prevented the construction of levees. The project also provides for

the construction of navigable floodgates on Bayou Lafourche at the upper and lower

limits of the project area. In lieu of the eight gravity drainage structures that were

authorized as part of the project, the local sponsor chose to pay the additional cost for

pumping stations. To date, the first and second lifts on all levee reaches have been

completed and the third and final lift has been completed on all but one reach. The

Larose Floodgate was completed in 1987 and the Golden Meadow Floodgate, now

officially known as the Leon Theriot Floodgate, was completed in 1985. The project is

approximately 97 percent complete. The Leon Theriot Lock was authorized in August

2005. The South Lafourche Levee District has initiated construction of the lock and has

completed 2 of the 3 construction contracts.

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Morganza to the Gulf of Mexico Risk Reduction Project. The Morganza to the Gulf

project area is bounded on the west by Bayou du Large and State Highway 311 and on

the east by Bayou Lafourche with the east and west boundaries forming an apex at

Thibodaux, LA. The southern boundary is the Gulf of Mexico. The project consists of

approximately 72 miles of earthen levee, nine 56-ft. sector gate structures, three 125-ft.

floodgates, 13-floodgate structures, 13-tidal exchange structures and a lock complex

consisting of a lock in the Houma Navigation Canal measuring 110-feet by 800-feet, an

adjoining floodgate measuring 250 feet, and a dam closure. The structural features are

integrated into the levee alignment to provide flood protection, drainage, environmental

benefits, and navigational passage. A Post-Authorization Change report is being

developed for the project due to cost increases subsequent to authorization. Future

Congressional authorization and appropriation will be needed before Federally-funded

construction can begin. However, construction by the local sponsor has begun on two of

the ten levee reaches.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 4.11. Existing Federal and Local Levees in the Vicinity of the Project Area and Proposed Morganza to the Gulf Alignment. Sources:Terrebonne Parish Consolidated Government and Interagency Performance Evaluation Task Force

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4.2.15.9 Natural Resources

4.2.15.9.1 Commercial Fisheries

4.2.15.9.1.1 Historic and Existing Conditions

Louisiana’s coastal wetlands are the richest estuaries in the country for fisheries

production. Commercially and recreationally important species such as brown and white

shrimp, blue crabs, eastern oysters, and menhaden are abundant. Louisiana has

historically been an important contributor to the Nation’s domestic fish and shellfish

production, and is one of the primary contributors to the Nation’s food supply for protein.

While Louisiana has long been the Nation’s largest shrimp and menhaden producer, it has

also recently become the leading producer of blue crabs and oysters.

Total fish and shellfish landings in Louisiana were 918 million pounds in 2008 (NMFS

2009). Total fish and shellfish landings for ports in the vicinity of the project area were

58 million pounds in 2008 (NMFS Fisheries Statistics Division 2009 – personal

communication). The percentage contribution of Louisiana total landings to the gulf

region was 72 percent and to the Nation was 11 percent. Dockside revenues for

commercial fisheries in coastal Louisiana were $275 million in 2008 (NMFS 2009).

These revenues were the third largest for any state in the contiguous United States. Table

4.24 shows the trend in total landings for the project vicinity, Louisiana, the Gulf region,

and the Nation, attesting to the substantial productivity of Louisiana’s coastal marshes

(NMFS Fisheries Statistics Division 2009 – personal communication).

Table 4.24. Total Landings of Fish and Shellfish (millions of pounds, millions of dollars).

Location 1985 1990 1995 2000 2005 2008

U.S. 6380.7 9826.1 9893.0 9142.9 9713.3 8343.8

$2359.5 $3654.2 $3819.4 $3676.6 $3952.7 $4401.7

Gulf

Region

2417.0 1659.5 1489.0 1795.4 1198.2 1277.6

$622.3 $667.2 $764.3 $997.3 $625.0 $661.4

Louisiana 1722.1 1113.0 1128.6 1359.2 849.3 918.5

$241.8 $270.0 $315.8 $421.2 $251.7 $274.9

Project

Vicinity1

424.5 331.8 269.4 95.3 84.5 58.4

$87.4 $98.9 $96.0 $123.6 $93.9 $76.7 1 Includes ports of Dulac-Chauvin, Golden Meadow-Leeville, and Morgan City-Berwick.

The most important species, in terms of Louisiana dockside revenue in 2008, were white

and brown shrimp. Louisiana caught approximately 88 million pounds of white and

brown shrimp in 2008 with a dockside value of approximately $130 million, which is

approximately 45 percent of the United States’ total landings, and more than what was

caught in any other state. Ports in Terrebonne, Lafourche, and St. Mary Parishes landed

approximately 31 million pounds of white and brown shrimp in 2008 with a dockside

value of $41 million. Almost all of the shrimp caught in Louisiana and along the gulf

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coast have spent an important part of their life living and growing in the Louisiana

coastal marshes.

Another important species harvested in the area is menhaden. Menhaden is processed to

produce both fishmeal and fish oil. Fishmeal is used as a high protein animal feed. The

broiler (chicken) industry is currently the largest user of menhaden meal, followed by the

turkey, swine, pet food, and ruminant (cattle/livestock) industries. The Louisiana

menhaden fisheries landings were the largest in the Nation in 2008 at 738 million pounds,

more than twice as much as the next closest state. The percent of dockside value from

Louisiana to that of the Nation was over 51 percent. Menhaden are an important species

in Terrebonne, Lafourche, and St. Mary Parishes as well, but landings for this species are

reported at other ports.

In 2008, Louisiana had 55 percent of the Nation’s eastern oyster catch, 12.7 million

pounds, with 47 percent of the value, $38.8 million. Ports in Terrebonne, Lafourche, and

St. Mary parishes landed 4.3 million pounds in 2008 at a value of $11.7 million (NMFS

Fisheries Statistics Division 2009 – personal communication). Louisiana also landed

more blue crabs in 2008 than any other state and accounted for approximately 26 percent

of the Nation’s total. Louisiana has been the largest producer of blue crabs, by weight, in

the Nation since 2000, surpassing other states that were the dominant producers in the

1990s. Blue crab landings in Louisiana in 2008 were 41.5 million pounds with a

dockside value of $31.8 million. Blue crab landings at ports in Terrebonne, Lafourche,

and St. Mary Parishes in 2008 were 15.6 million pounds with a dockside value of $11.9

million (NMFS Fisheries Statistics Division 2009 – personal communication).

4.2.15.9.2 Oyster Leases

4.2.15.9.2.1 Historic and Existing Conditions

Louisiana is the top producer of the eastern oyster in the United States, averaging

approximately 13.1 million pounds per year since 2000, with an average value of $34.0

million (NMFS Fisheries Statistics Division 2009 – personal communication). The

fishery has two main sources - privately leased grounds, and public seed grounds. The

State of Louisiana owns the water bottoms and leases out acreage to oyster fishermen.

The public grounds are open to harvesting by all licensed fishermen, but are only open

during the public season, which runs from September through March. Oysters can be

harvested from the private grounds throughout the year.

Approximately 390,000 acres are currently under lease in Louisiana, compared to less

than 250,000 acres during the mid 1970s and early 1980s (Diagne and Keithly 1988).

Terrebonne and Lafourche parishes currently account for approximately 115,000 acres as

compared to 57,000 in the 1970s and early 1980s. The leases have 15-year terms and are

leased from the state for $2 per acre per year. See figure 4.7.

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4.2.16 Hazardous, Toxic, and Radioactive Wastes

[Phase I Environmental Site Assessment Summary]

4.2.16.1 Historic and Existing Conditions

The USACE is obligated under Engineer Regulation (ER) 1165-2-132 to assume

responsibility for the reasonable identification and evaluation of all HTRW

contamination within the vicinity of the proposed action. ER 1165-2-132 identifies the

USACE policy to avoid the use of project funds for HTRW removal and remediation

activities. Costs for necessary special handling or remediation of wastes (e.g., those

regulated by the RCRA), pollutants and other contaminants, which are not regulated

under the CERCLA, will be treated as project costs if the requirement is the result of a

validly promulgated Federal, state or local regulation.

HTRW investigations facilitate early identification and consideration of HTRW

problems. The Civil Works Project Plan routinely includes a phased and documented

review to provide for early identification of HTRW potential at project sites. ER 1165-2-

132 requires that viable options to avoid HTRW problems be determined and a procedure

for resolution of HTRW concerns be established.

The discharge of dredged material into waters of the U.S. is regulated under the Clean

Water Act (CWA), and the Marine Protection and Sanctuaries Act governs the

transportation of dredged material to ocean waters for the purpose of disposal. The

RCRA hazardous waste management regulations, promulgated pursuant to RCRA (42

U.S.C. 6905) specifically exempt dredge material from the hazardous waste definition if

that material is covered by:

1) a permit issued under Section 404 of the Clean Water Act, 33 U.S.C. 1344;

2) a permit issued under Section 103 of the Marine Protection, Research and

Sanctuaries Act of 1972 33 U.S.C. 1413; or

3) the administrative equivalent of such permits where the work involves an Army

Corps of Engineers civil works project, 40 C.F.R. 261.4(g), 63 F.R. 65874,

65921; November 30, 1998.ER1165-2-132 states, dredged material and sediments

beneath navigable waters proposed for dredging qualify as HTRW only if they are

within the boundaries of a site designated by the EPA or a state for a response

action (either a removal or a remedial action) under CERCLA, or if they are a part

of a NPL site under CERCLA.

As reported in the Phase I ESA, during records research and site reconnaissance it was

determined that areas adjacent to some of the project features contained Recognized

Environmental Conditions (REC’s) that presented a low to moderate risk of affecting

potential project features, albeit that no REC’s were noted within direct proximity of land

associated with any of the potential project features.

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Should at anytime during the project HTRW concerns arise, the CEMVN would take

immediate actions to investigate the concerns. Should an HTRW issue be determined

and the development of a response action required, CEMVN would coordinate with the

appropriate Federal and state authorities to implement an approved response action.

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5.0 ENVIRONMENTAL CONSEQUENCES

This chapter describes the potential environmental consequences of implementing

alternative plans considered. The following analysis compares the No Action Alternative

to the seven alternatives analyzed in detail: Alternative Plans 2, 3, 4, 5, 6, 7, and 8.

Alternative 2 is the Recommended Plan (RP). The development of alternatives and the

plan formulation process are described in Chapter 3 Alternatives.

A comparison of the direct, indirect, and cumulative impacts of alternatives is presented

herein. Direct impacts are those effects that are caused by the proposed action and occur

at the same time and place (Section 1508.8(a) of 40 CFR Parts 1500-1508). For example,

the use of dredged material to create acres of marsh habitat would be a direct impact.

Indirect impacts are those effects that are caused by the action and are later in time or

further removed in distance, but are still reasonably foreseeable (Section 1508.8(b) of 40

CFR Parts 1500-1508). For example, shoreline protection features reduce the long-term

rate of erosion to interior wetlands. Cumulative impacts would be the aggregate of

impacts to the environment resulting from the proposed action in combination with other

ongoing actions, and actions being considered within the reasonably foreseeable future.

Cumulative impacts are the effects on the environment that results from the incremental

impact of the action when added to other past, present, and reasonably foreseeable future

actions, regardless of what agency (Federal or non-Federal) or person undertakes such

actions. Cumulative impacts can result from actions that individually are minor, but

collectively result in significant actions taking place over time (Section 1508.7 40 CFR

Parts 1500-1508). For example, the incremental impacts of emergent wetland creation at

several localized areas could significantly modify an entire basin’s habitat diversity. The

cumulative impact analysis followed the 11-step process described in the 1997 report by

the Council of Environmental Quality entitled “Considering Cumulative Effects Under

the National Environmental Policy Act.”

This environmental analysis evaluates and compares, from a qualitative and quantitative

perspective, the seven alternatives carried over for detailed analysis. Impact analysis

described in this chapter is based on a combination of scientific and engineering analyses,

professional judgment, and previously compiled information.

Description of Alternative Plans

A review of Alternative Plans and associated features is presented here and in Table 5.1.

Figure 5.1 depicts locations of all features. Details on the plan formulation process can

be found in Chapter 3. Construction related impacts of features are presented in Table

5.2.

Alternative 2 (NER Plan and RP) - Strategy: Utilize Existing Flow and Management

Measures.

This alternative would redistribute existing freshwater flows to benefit project area

marshes. To achieve this, GIWW constrictions would be eliminated. Additionally, the

following measures to restrict, increase, and control water are proposed for each of the

three subunits. In the West – Bayou Penchant Area, dredging, a sediment plug, and a

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weir would be utilized. In the Central – Lake Boudreaux Area, culverts, levees,

dredging, marsh terraces and berms, sediment plugs, modified operation of the future

HNC lock complex, and a large sluice gated box culvert are proposed. In the East –

Grand Bayou Area, culverts, dredging, gaps in canal spoil banks, marsh berms, sediment

plugs, and removal of a weir and soil plug are proposed.

Alternative 3 - Strategy: Increase Atchafalaya River Flows and Utilize Management

Measures.

This alternative would increase Atchafalaya River inflows and redistribute existing and

increased flows of freshwater. Proposed measures to accomplish this include all

measures from Alternative 2 with the addition of the opening and structure in the Avoca

Island levee (WS4) and the shoreline protection in Avoca Island Cutoff/Bayou Chene

(WO2). To increase flows from the Atchafalaya River, water will be moved from Bayou

Shaffer to the Avoca Island Cutoff/Bayou Chene. This will be accomplished by creating

an opening through the Avoca Island levee and installing a large gated diversion structure

in the opening.

Alternative 4 - Strategy: Increase Flow from East of the Project Area and Utilize

Management Measures.

This alternative would increase freshwater flows from east of the project area and

redistribute existing and increased flows of freshwater. Alternative 4 includes all but one

of the measures in Alternative 2, and has two additional measures in the East – Grand

Bayou Area. In Alternative 2, a new Hwy. 24 bridge with Obermeyer gates between the

piers (EC5) is proposed to connect the GIWW to Grand Bayou. In Alternative 4, this

measure is replaced by a pump station (ES2). The pump station would increase

freshwater delivery to the Grand Bayou watershed but not the other subunits. The second

new measure is a soil plug (EP8) in Bayou L’eau Bleu. Bayou L’eau Bleu connects the

canal receiving the pump station outflow to the GIWW. The pump station would pump

water from the GIWW, thus the soil plug is necessary to prevent recirculation of water.

Alternative 5 - Strategy: Increase Flow from the East and from the Atchafalaya

River and Utilize Management Measures.

This alternative would increase flows from the east and west and redistribute existing and

increased flows of freshwater. This alternative is a combination of Alternatives 3 and 4.

The only measure in Alternative 3 not within this alternative is the Hwy. 24 bridge with

Obermeyer gates (EC5) which is replaced by a pump station (ES2), as in Alternative 4.

Alternative 6 - Strategy: Increase Atchafalaya River Flow and Utilize Management

Measures.

This alternative would increase Atchafalaya River inflows and improve the passage of

freshwater through the GIWW while slowing water passage to the gulf through the HNC.

A large gated diversion structure (WS4) would be placed in the new opening created in

the Avoca Island levee. Shoreline protection would be placed (WO2) in Bayou Chene

and Avoca Island Cutoff. To improve freshwater flows through the GIWW to Grand

Bayou, the following measures are proposed. In East – Grand Bayou Area, dredging is

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proposed to connect Grand Bayou to the GIWW (ED5) and enlarge Grand Bayou (ED3).

Where ED5 goes through Hwy. 24, a new bridge with Obermeyer gates between the piers

(EC5) is proposed. In Central – Lake Boudreaux Area, the GIWW is constricted as it

passes under Hwy. 24. The Hwy. 24 bridge columns do not allow for channel

enlargement. Therefore, dredging a new secondary channel with two culverts, one under

each Hwy. 24 bridge, is proposed. Modifying the operation of the HNC Lock Complex is

also included in this alternative.

Alternative 7 - Strategy: Utilize Existing Flow and Management Measures.

This alternative would slow the movement of freshwater to the Gulf of Mexico and thus

put additional freshwater onto northern Terrebonne marshes. The one measure in this

alternative is modified operation of the proposed HNC Lock Complex (CL1). The HNC

Lock Complex is part of the proposed U.S. Army Corps of Engineers Morganza to the

Gulf project for flood risk management. The Lock Complex includes a set of navigable

sector gates. Under normal operation, the navigable sector gates would remain open with

unrestricted vehicle passage and closed during storm events and when the Atchafalaya

River is low. This alternative proposes to keep the sector gates closed more frequently to

hold water back thus moving freshwater onto northern marshes. When the sector gates

are closed boat traffic would travel through the lock chambers. As part of this

alternative, an industry traffic management plan would be developed for vessels

exceeding the lock size that will require the sector gates to be opened.

Alternative 8 – Strategy: Utilize Existing Flow and Management Measures to Focus

Fresh Water Flows on the Most Critical Areas of the East and Central Study Sub

Units.

This alternative would redistribute existing freshwater within the study area to benefit the

eastern and central Terrebonne marshes using a variety of measures in an effort to focus

freshwater distribution to the most critical areas of marsh decline in the study area. This

alternative represents an increment between Alternative 7 and Alternative 2 and contains

many of the features of Alternative 2. In the Central – Lake Boudreaux Area, culverts,

levees, dredging, sediment plugs, modified operation of the future HNC lock complex,

and a large sluice gated box culvert are proposed. In the East – Grand Bayou Area,

culverts, dredging, gaps in canal spoil banks, sediment plugs, and removal of a weir and

soil plug are proposed.

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Table 5.1 Alternative Measures.The following measures were included in one or more of the final alternative plans. For site plans and typical sections refer to Engineering Appendix L Annex 4.

Alt ID1 Measure Name Description No. of Barrels Size/ Width2 Invert/ Channel Bottom2 Lgth2 Purpose

All CL1 Central Lock Complex #1 Multi-purpose operation of proposed HNC4 Lock Complex N/A N/A -7 N/A Optimize operation of HNC lock for distribution of fresh water and prevention of saltwater intrusion

2, 3,6, 8 EC5 East Culvert #5 Bridge construction with Obermeyer gates installed between the piers N/A 80 x 20 -14 552 Convey fresh water from GIWW5 to Grand Bayou under Hwy 24, same location as ES2

Alternative 2 - 5, 8

EC23 East Culvert #2 Box culvert 5 5x5 -4.5 26 Convey flow through existing levee from Grand Bayou to W

EC33 East Culvert #3 Flap gated box culverts w/variable crest outfall 10 5x5 -5 75 Convey fresh water to the W through an existing levee and prevent saltwater movement from Grand Bayou to NWED63 East Dredge Channel #6 Dredge a portion of Grand Bayou N/A 290 -14 16818 Allow water movement to E Grand Bayou marshesEG13 East Spoil Gap #1 Gap in canal spoil bank N/A 1.7 acres -0.5 750 Allow movement of fresh water from unnamed canal to marshes to the S/SWEG23 East Spoil Gap #2 Gap in canal spoil bank N/A 0.5 acres -0.5 400 Allow movement of fresh water from unnamed canal to marshes to the EEP7 East Plug #7 Boat bay on Cutoff Canal at junction with Point au Chien N/A 20 -5 360 To retain fresh water to N; prevent saltwater from SEX13 East Removal #1 Rock weir removal N/A 50 W -5 100 Increase water movement through canal - distribute fresh water from Grand BayouEX23 East Removal #2 Soil plug removal N/A 50 W -5 130 Increase water movement through canal - distribute fresh water from Grand Bayou/St. Louis CanalCC3 Central Culvert #3 Gated control structure 6 10x10 -10 175 Increase fresh water delivery from HNC4 through Bayou Provost to Bayou Grand Caillou/Lake BoudreauxCC53 Central Culvert #5 Aluminum flap-gated culvert 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux system

CC63 Central Culvert #6 Aluminum flap-gated culvert 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux system

CC73 Central Culvert #7 Aluminum flap-gated culvert 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux systemCC83 Central Culvert #8 Aluminum flap-gated culvert 1 4x4 -5 48 Convey fresh water from N to S into N Lake Boudreaux systemCC93 Central Culvert #9 Aluminum flap-gated culvert 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux systemCC103 Central Culvert #10 Aluminum flap-gated culvert 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux systemCC113 Central Culvert #11 Aluminum flap-gated culvert 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux system

CC123 Central Culvert #12 Aluminum flap-gated culvert 1 4x4 -5 40 Convey fresh water from N to S into N Lake Boudreaux system

CC133 Central Culvert #13 Box culverts with sluice gates under Hwy 57 6 10x10 -10 175 Increase fresh water movement from HNC4/Bayou Grand Caillou to N Lake Boudreaux

CC143 Central Culvert #14 Flap-gates each with a stop log bay 3 4x4 -5 45 Convey fresh water from new channel to N marshesCC153 Central Culvert #15 Timber weir placed at 90 to flow with boat openings N/A 68 W -2/-3.5 N/A Prevent short circuiting of fresh water through the N/S Gulf S Pipeline canalCD1 Central Dredge Channel #1 Dredge Bayou Provost N/A 70 W -10 5,691 Increase fresh water delivery from HNC4 through CC3 to Bayou Grand Caillou/Lake Boudreaux

CD2 Central Dredge Channel #2 Dredge part of Bayou Butler N/A 45 W -10 1000 Increase fresh water movement from HNC4 through CS1 to Bayou Grand Caillou/Lake BoudreauxCD63 Central Dredge Channel #6 Dredge new water conveyance channel N/A 45 W -10 7014 Convey fresh water from Bayou Pelton enlargement through CC14 to N Lake Boudreaux marshesCD73 Central Dredge Channel #7 Dredge Bayou Pelton to enlarge it N/A 70 W -10 6416 Increase fresh water movement from HNC4 through CC13 to Bayou Grand Caillou/N Lake BoudreauxCP1 Central Plug #1 Soil plug in Robinson Canal N/A 175 W -10 25 Retain fresh water in Lake Boudreaux basin; prevent saltwater intrusion from Bayou Petit CaillouCP23 Central Plug #2 Soil plug in canal near Bayou Butler N/A 60 W -10 25 Prevent short circuiting of fresh water through the N/S Gulf S Pipeline canalCS1 Central Diversion Structure #1 Bayou Butler sluice gated box culverts under Hwy 57 6 10x10 -10 100 Increase fresh water movement from HNC4 to Bayou Grand Caillou/Lake Boudreaux

2-5

EC6 East Culvert #6 Flap gated box culverts 8 8x8 -7 50 Allow water movement down St. Louis Canal under Hwy 24EC7 East Culvert #7 Flap gated box culverts 8 8x8 -7 40 Allow water movement down St. Louis Canal under roadED2 East Dredge Channel #2 Canal dredging N/A 50 -8 56270 Allow water movement from GIWW5 through EC6 & 7 to Grand Bayou basinED73 East Dredge Channel #7 Canal dredging N/A 150 -14 13081 Allow water movement further down Grand Bayou

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Alt ID1 Measure Name Description No. of Barrels Size/ Width2 Invert/ Channel Bottom2 Lgth2 Purpose

EM1 East Marsh Berm #1 A linear soil berm placed perpendicular to flow N/A 30 W N/A 13000 To slow fresh water movement to the gulf; prevent saltwater intrusion from S

Alternatives 2 - 5

EM3 East Marsh Berm #3 A linear soil berm placed perpendicular to flow N/A 30 W N/A 37000 To slow fresh water movement to the gulf; prevent saltwater intrusion from S

CC4 Central Culvert #4 Gated control structure 6 10x10 -10 175 Increase fresh water movement from HNC4 to Bayou Grand Caillou/Lake Boudreaux

CD3 Central Dredge Channel #3 Dredge Falgout Canal N/A 70 W -10 4426 Increase fresh water movement from HNC4 through CC4 to Bayou Grand Caillou/Lake BoudreauxCLV13 Central Levee #1 New forced drainage levee N/A +8 H N/A 5173 Prevent potential flooding from proposed increase in flows to N Lake BoudreauxCLV23 Central Levee #2 New forced drainage levee N/A +8 H N/A 1760 Prevent potential flooding from proposed increase in flows to N Lake BoudreauxCM2 Central Marsh Berm #2 A linear soil berm placed perpendicular to flow N/A 30 W N/A 11255 Retain fresh water in Lake Boudreaux and marshes to N; prevent saltwater intrusion from SCM3 Central Marsh Berm #3 A linear soil berm placed perpendicular to flow N/A 30 W N/A 8975 Retain fresh water in Lake Boudreaux and marshes to N; prevent saltwater intrusion from SCM4 Central Marsh Berm #4 A linear soil berm placed perpendicular to flow N/A 30 W N/A 23458 Retain fresh water in marshes to N; prevent saltwater intrusion from SCT13 Central Terracing #1 A grid of 10’ wide berms perpendicular to surge N/A 359 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT23 Central Terracing #2 A grid of 10’ wide berms perpendicular to surge N/A 40 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT33 Central Terracing #3 A grid of 10’ wide berms perpendicular to surge N/A 109 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT63 Central Terracing #6 A grid of 10’ wide berms perpendicular to surge N/A 71 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT73 Central Terracing #7 A grid of 10’ wide berms perpendicular to surge N/A 83 acres -5 N/A Retain fresh water and prevent saltwater intrusionCT83 Central Terracing #8 A grid of 10’ wide berms perpendicular to surge N/A 156 acres -5 N/A Retain fresh water and prevent saltwater intrusionWD2 West Dredge Channel #2 Dredge a part of Carencro Bayou and create new canal N/A 200 -7 35463 Increase delivery of fresh water from Bayou Penchant to SE Penchant Basin marshesWP1 West Plug #1 Soil plug N/A 20 W -10 115 Retain fresher water in Bayou du Large and Lake Mechant and prevent saltwater intrusionWW23 West Weir #2 Rock filled sheet pile weir with boat openings N/A 940 W -12 100 Constrict Grand Pass by 90% to minimize water exchange between Bayou du Large and Caillou Lake

2 - 6, 8 ED33 East Dredge Channel #3 Canal dredging N/A 470 -14 16483 Convey fresh water from GIWW5 to Grand Bayou basin ED5 East Dredge Channel #5 Dredge new canal N/A 470 -14 1000 Convey fresh water from GIWW5 through ES2 or EC5 to Grand Bayou

Alt. 2 - 6CD4 Central Dredge Channel #4 Dredge a new secondary channel along the GIWW at Hwy 24 bridges N/A 70 -20 1852 Increase water volume moving past GIWW5constriction CC1 Central Culvert #1 Box culvert in CD4 channel under Hwy 24 bridge 6 10x10 -20 115 Increase water volume moving past GIWW5constriction CC2 Central Culvert #2 Box culvert in the CD4 channel under Hwy 24 bridge 6 10x10 -20 115 Increase water volume moving past GIWW5constriction

WD3 West Dredge Channel #3 Dredge a portion of GIWW5 N/A 50 -36 16339 Eliminate constriction in GIWW5

Alt. 3, 5, 6 WO2 West Shoreline Protection #2 Riprap the banks of Bayou Chene and Avoca Island Cutoff around the mouth of Bayou Penchant N/A Varies N/A 48000 Protect Penchant basin marshes from increased project-related flows WS4 West Diversion Structure #4 Gated box culverts 6 15x15 -15 365 Increase flow from Atchafalaya River to GIWW5 by moving water from Bayou Shaffer to Avoca Island Cutoff/Bayou Chene4&5EP8 East Plug #8 Soil plug in Bayou L’eau Bleu adjacent to Hwy 24 bridge N/A 200 W -10 25 Prevent recirculation of water from measure ES2, pump station

ES2 East Diversion Structure #2 Pump station under Hwy 24 4 552 W -14 188 Pump water from GIWW5 to Grand Bayou, same location as EC5

1. Measure ID – Measures are identified by a unique sequence such as WC1. The first letter describes the subunit location: W = Bayou Penchant, C = Lake Boudreaux, and E = Grand Bayou. The second and third letters describe the typeof measure: C = culvert, D = dredge, M & MC = marsh creation, X = removal, S = structure, L = lock, G = gap, P = plug, LV = levee, T = terracing, O = shoreline protection and W = weir. The number provides a unique ID for that 5particular type of measure in that subunit. In some cases, measures were redesigned but the ID was retained.2. All measurements are approximate. Unless otherwise noted, all measurements are in feet.3. Measures in bold were proposed as part of a Coastal Wetlands Planning, Protection, and Restoration Act project.4. HNC – Houma Navigation Canal5. GIWW – Gulf Intracoastal Waterway 10

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Figure 5.1. Feature Locations.

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Table 5.2. Impacts Associated with Construction of Project Features.

Feature

ID

Feature Name Construction

Impacts1

(acres)

Construction Impact

Habitat Type

Temporary

Work Area

Impacts2

(acres)

ED2 East Dredge

Channel #2

98.8

114.0

40.5

55.1

Swamp/Wetland Forest

Intermediate Marsh

Brackish Marsh

Open Water

1.3

ED3 East Dredge

Channel #3

20.6

120.0

46.8

88.1

Swamp/Wetland Forest

Intermediate Marsh

Brackish Marsh

Open Water

3.4

ED5 East Dredge

Channel #5

15.3 Upland/Open Water 3.4

ED6 East Dredge

Channel #6

74.0

140.5

Brackish Marsh

Open Water

2.5

ED7 East Dredge

Channel #7

20.9

98.5

Brackish Marsh

Open Water

1.8

EP7 East Plug #7 0.9 Upland/Open Water 0.6

EP8 East Plug #8 0.2 Upland/Open Water 0.1

EG1 East Spoil Gap

#1

2.0 Upland/Open Water 2.0

EG2 East Spoil Gap

#2

2.0 Upland/Open Water 2.0

ES2 East Diversion

Structure #2

5.8 Upland/Open Water 3.9

EX1 East Removal #1 0.0 Upland/Open Water 0.4

EX2 East Removal #2 0.0 Upland/Open Water 0.4

EC2 East Culvert #2 0.1 Upland/Open Water 0.1

EC3 East Culvert #3 0.1 Upland/Open Water 0.1

EC5 East Culvert #5 5.8 Upland/Open Water 3.9

EC6 East Culvert #6 0.1 Upland/Open Water 0.1

EC7 East Culvert #7 0.1 Upland/Open Water 0.1

EM1 East Marsh Berm

#1

25.0 (creation) Brackish Marsh 24.4

EM3 East Marsh Berm

#3

72.0 (creation) Saline Marsh 67.3

CC1 Central Culvert

#1

0.4 Upland/Open Water 0.3

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Feature

ID

Feature Name Construction

Impacts1

(acres)

Construction Impact

Habitat Type

Temporary

Work Area

Impacts2

(acres)

CC2 Central Culvert

#2

0.4 Upland/Open Water 0.3

CC3 Central Culvert

#3

0.2 Upland/Open Water 0.1

CC4 Central Culvert

#4

0.1 Upland/Open Water 0.1

CC5 Central Culvert

#5

0.1 Upland/Open Water 0.1

CC6 Central Culvert

#6

0.1 Upland/Open Water 0.1

CC7 Central Culvert

#7

0.1 Upland/Open Water 0.1

CC8 Central Culvert

#8

0.1 Upland/Open Water 0.1

CC9 Central Culvert

#9

0.1 Upland/Open Water 0.1

CC10 Central Culvert

#10

0.1 Upland/Open Water 0.1

CC11 Central Culvert

#11

0.1 Upland/Open Water 0.1

CC12 Central Culvert

#12

0.1 Upland/Open Water 0.1

CC13 Central Culvert

#13

1.1 Upland/Open Water 2.5

CC14 Central Culvert

#14

0.1 Upland/Open Water 0.3

CC15 Central Culvert

#15

0.3 Upland/Open Water 0.2

CD1 Central Dredge

Channel #1

2.6

5.4

24.0

Swamp/Wetland Forest

Intermediate Marsh

Open Water

1.3

CD2 Central Dredge

Channel #2

3.3 Upland/Open Water 1.1

CD3 Central Dredge

Channel #3

8.5

10.2

Intermediate Marsh

Open Water

1.0

CD4 Central Dredge

Channel #4

9.3 Upland/Open Water 1.2

CD6 Central Dredge

Channel #3

17.2

23.7

Swamp/Wetland Forest

Freshwater Marsh

1.3

CD7 Central Dredge

Channel #7

9.2

7.4

Swamp/Wetland Forest

Open Water

1.5

CL1 Central Lock

Complex #1

N/A N/A N/A

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Feature

ID

Feature Name Construction

Impacts1

(acres)

Construction Impact

Habitat Type

Temporary

Work Area

Impacts2

(acres)

CM2 Central Marsh

Berm #2

22.0 (creation) Brackish Marsh 20.7

CM3 Central Marsh

Berm #3

18.0 (creation) Brackish Marsh 16.5

CM4 Central Marsh

Berm #4

45.0 (creation) Brackish Marsh 42.9

CP1 Central Plug #1 0.4 Upland/Open Water 0.2

CP2 Central Plug #2 0.1 Upland/Open Water 0.1

CS1 Central Diversion

Structure #1

1.1 Upland/Open Water 2.5

CT1 Central Terracing

#1

60.0 (creation) Brackish Marsh 158.0

CT2 Central Terracing

#2

7.0 (creation) Brackish Marsh 17.6

CT3 Central Terracing

#3

20.0 (creation) Brackish Marsh 48.0

CT6 Central Terracing

#6

15.0 (creation) Brackish Marsh 31.2

CT7 Central Terracing

#7

15.0 (creation) Brackish Marsh 36.4

CT8 Central Terracing

#8

30.0 (creation) Brackish Marsh 68.8

CLV1 Central Levee #1 18.4 Swamp/Wetland Forest 7.6

CLV2 Central Levee #2 4.4 Swamp/Wetland Forest 2.6

WD2 West Dredge

Channel #2

319.1

301.0

Freshwater Marsh

Open Water

2.0

WD3 West Dredge

Channel #2

168.6 Open Water 3.0

WO2 West Shoreline

Protection #2

149.4 Upland/Open Water 99.6

WP1 West Plug #1 0.3 Upland/Open Water 0.2

WS4 West Diversion

Structure #4

2.8 Upland/Open Water 1.8

WW2 West Weir #2 1.4 Upland/Open Water 0.9

1 Construction impact acreages listed for marsh creation features (marsh berms and

terracing) are acres of marsh created.

For purposes of construction impact analysis associated with dredge features, the

assumption was made that the dredge channel itself and the adjacent disposal site would

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result in marsh impacts. In reality, dredged material will be used beneficially to create

marsh habitat to the maximum extent practicable. However, the exact nature of the

dredged material and its utility in marsh creation, the locations of marsh creation sites,

and the acreage of created marsh habitat will not be determined until a later date, during

pre-construction engineering and design. Therefore, the aforementioned assumptions

were necessary in order to complete the impact analysis for project features. In light of

this, the estimates of negative impacts to marsh should be viewed as maximums as they

should be offset at least in part by beneficially using dredged material during

construction. For dredge feature WD3, adjacent disposal was not assumed due to the

existence of high quality swamp/wetland forest adjacent to the feature. In addition, the

proposed dredge channel does not extend beyond the existing channel width.

Therefore, no construction impacts to swamp/wetland forest were assumed in

conjunction with WD3.

2 For purposes of impact analysis, it was assumed that temporary work areas would be

located in upland and/or open water habitats with no impacts to wetlands. The exact

nature, extent, and duration of temporary work areas, however, would be determined

during pre-construction engineering and design. Impacts would be kept to a minimum

by use of proper construction techniques, temporary vegetative cover during

construction, and regrading and permanent vegetation establishment at the end of

construction.

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5.1 Soils and Waterbottoms

5.1.1 No Action Alternative (Future without Project Conditions)

Soil erosion and land loss in the project area would continue into the future. Natural and

man-made levees would continue to subside and marsh soils would not be able to

maintain their elevations due to subsidence, decreased plant productivity, and wave

erosion. Net primary productivity within the project area would continue to decline and

existing wetland vegetation would continue to diminish. The ongoing conversion of

existing fragmented emergent wetlands to shallow open water would continue with

associated indirect impacts on coastal vegetation, fish and wildlife resources, EFH,

recreation, aesthetics, and socioeconomic resources. Waterbodies would grow larger and

wave erosion would accelerate causing further land loss, thus making coastal

communities more vulnerable to tropical storms. No large-scale loss of farmland would

be expected from subsidence. The greatest loss of farmland would come from conversion

to development.

5.1.2 Alternative 2 (NER Plan and RP)

5.1.2.1 Direct

Direct impacts to soils and substrate from implementation of Alternative 2 would

primarily result from project-related activities that would directly use, remove, or

otherwise disturb soil resources. Direct adverse impacts to soil resources would

primarily result from activities associated with construction of project features such as

excavation of existing soil for water control structures, dredge channels, and temporary

retention dikes. Implementation of Alternative 2 would result in 148 acres of swamp,

343 acres of fresh marsh, 248 acres of intermediate marsh, and 182 acres of brackish

marsh being directly converted to open water. Alternative 2 would also result in 23 acres

of swamp being converted to upland (levee). These direct impacts would be the result of

dredge features WD2, CD1, CD3, CD6, CD7, ED2, ED3, ED6, and ED7 and levee

features CLV1 and CLV2 (Table 5.2). It should be noted that, for purposes of impact

analysis associated with dredge features for all Alternatives, the assumption was made

that the dredge channel itself and the adjacent disposal site would result in marsh

impacts. In reality, dredged material will be used beneficially to create marsh habitat to

the maximum extent practicable. However, the exact nature of the dredged material and

its utility in marsh creation, the locations of marsh creation sites, and the acreage of

created marsh habitat will not be determined until a later date, during pre-construction

engineering and design. Therefore, the aforementioned assumptions were necessary in

order to complete the impact analysis for project features. In light of this, the estimates

of negative impacts to marsh should be viewed as maximums as they should be offset at

least in part by beneficially using dredged material during construction.

Temporary impacts to soils and waterbottoms would also occur in temporary work areas

needed for construction of project features (Table 5.2). It is estimated that 585 acres of

temporary work areas will be needed for construction of Alternative 2. No additional

impacts to marsh or swamp habitat are anticipated from these activities, but open water

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habitats and upland habitats would be disturbed. Soil compaction, rutting, rill, and gully

erosion at construction sites would occur. The exact nature, extent, and duration of

temporary work areas and associated impacts would be determined during preconstruction engineering and design. Impacts would be kept to a minimum by use of

proper construction techniques such as silt curtains, temporary vegetative cover during

construction, and regrading and permanent vegetation establishment at the end of

construction.

Alternative 2 would also create 257 acres of brackish marsh and 72 acres of saline marsh

as a result of features CM2, CM3, CM4, CT1, CT2, CT3, CT6, CT7, CT8, EM1, and

EM3 (Table 5.2).

5.1.2.2 Indirect

Indirect impacts to soil resources would primarily result from long-term and far afield

effects of freshwater inputs, which would nourish and protect existing wetlands over

much of the project area. Vegetated wetlands would be enhanced by diversions of

freshwater and nutrients which would increase plant productivity and vertical accretion of

organic soils. Some areas are projected to decline at a faster rate with implementation of

Alternative 2 due to a reduction in freshwater and associated nutrients (see Figure 5.2).

Overall, Alternative 2 would reduce land loss in the project area from 101,570 acres to

91,915 acres, thus preventing 9,655 acres of emergent marsh soils from being converted

to open water over the 50-year period of analysis. Alternative 2 would generate 3,220

AAHUs (Figure 5.2).

5.1.2.3 Cumulative

Alternative 2 would have positive synergistic effects on soil resources when combined

with other Federal, state, local, and private restoration efforts (Table 5.6). Implementing

Alternative 2 would contribute to reducing regional rates of marsh soil loss by an

estimated 9,655 net acres over the 50-year period of analysis.

5.1.3 Alternative 3

5.1.3.1 Direct

Direct impacts of Alternative 3 on soils and substrate would be similar to those of

Alternative 2.

5.1.3.2 Indirect

Indirect impacts of Alternative 3 on soils and substrate would be similar to those of

Alternative 2, but to a greater degree. Alternative 3 would reduce land loss in the project

area from 101,570 acres to 91,262 acres, thus preventing 10,308 acres of emergent marsh

soils from being converted to open water over the 50-year period of analysis. Alternative

3 would generate 3,325 AAHUs (Figure 5.3).

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5.1.3.3 Cumulative

Alternative 3 would have positive synergistic effects on soil resources when combined

with other Federal, state, local, and private restoration efforts (Table 5.6). Implementing

Alternative 3 would contribute to reducing regional rates of marsh soil loss by an

estimated 10,308 net acres over the 50-year period of analysis.

5.1.4 Alternative 4

5.1.4.1 Direct

Direct impacts of Alternative 4 on soils and substrate would be similar to those of

Alternative 2.

5.1.4.2 Indirect

Indirect impacts of Alternative 4 on soils and substrate would be similar to those of

Alternative 2, but to a greater degree. Alternative 4 would reduce land loss in the project

area from 101,570 acres to 89,366 acres, thus preventing 12,204 acres of emergent marsh

soils from being converted to open water over the 50-year period of analysis. Alternative

4 would generate 4,258 AAHUs (Figure 5.4).

5.1.4.3 Cumulative

Alternative 4 would have positive synergistic effects on soil resources when combined

with other Federal, state, local, and private restoration efforts (Table 5.6). Implementing

Alternative 4 would contribute to reducing regional rates of marsh soil loss by an

estimated 12,204 net acres over the 50-year period of analysis.

5.1.5 Alternative 5

5.1.5.1 Direct

Direct impacts of Alternative 5 on soils and substrate would be similar to those of

Alternative 2.

5.1.5.2 Indirect

Indirect impacts of Alternative 5 on soils and substrate would be similar to those of

Alternative 2, but to a greater degree. Alternative 5 would reduce land loss in the project

area from 101,570 acres to 87,636 acres, thus preventing 13,934 acres of emergent marsh

soils from being converted to open water over the 50-year period of analysis. Alternative

5 would generate 4,719 AAHUs (Figure 5.5).

5.1.5.3 Cumulative

Alternative 5 would have positive synergistic effects on soil resources when combined

with other Federal, state, local, and private restoration efforts (Table 5.6). Implementing

Alternative 5 would contribute to reducing regional rates of marsh soil loss by an

estimated 13,934 net acres over the 50-year period of analysis.

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5.1.6 Alternative 6

5.1.6.1 Direct

Direct impacts of Alternative 6 on soils and substrate would be similar to those of

Alternative 2, but to a lesser degree. Implementation of Alternative 6 would result in 141

acres of intermediate marsh and 47 acres of brackish marsh being directly converted to

open water. These direct impacts would be the result of dredge feature ED3. 117 acres

of temporary impacts to open water and uplands due to temporary work areas would also

occur (Table 5.2).

5.1.6.2 Indirect

Indirect impacts of Alternative 6 on soils and substrate would be similar to those of

Alternative 2, but to a lesser degree. Alternative 6 would reduce land loss in the project

area from 101,570 acres to 101,563 acres, thus preventing 7 acres of emergent marsh

habitat from being converted to open water over the 50-year period of analysis.

Alternative 6 would generate 776 AAHUs (Figure 5.6). The relatively large number of

AAHUs in comparison to the number of acres of emergent marsh loss prevented is due to

the fact that Alternative 6 would generate benefits associated with submerged aquatic

vegetation and marsh edge (WVA variables V2 and V3) despite very little prevention of

marsh loss.

5.1.6.3 Cumulative

Alternative 6 would have positive synergistic effects on soil resources when combined

with other Federal, state, local, and private restoration efforts (Table 5.6). Implementing

Alternative 6 would contribute to reducing regional rates of marsh soil loss by an

estimated 7 net acres over the 50-year period of analysis.

5.1.7 Alternative 7

5.1.7.1 Direct

No direct impacts to soils and substrates are anticipated from implementation of

Alternative 7.

5.1.7.2 Indirect

Implementation of Alternative 7 would increase land loss in the project area from

101,570 acres to 104,221 acres, thus leading to a net loss of 2,651 acres of emergent

marsh soils by conversion to open water over the 50-year period of analysis. However,

Alternative 7 would generate 243 AAHUs (Figure 5.7).

5.1.7.3 Cumulative

Despite resulting in a net loss of emergent marsh soils, Alternative 7 is still projected to

have a positive impact on marsh habitat in the project area (+243 AAHUs), and, to that

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extent, would have positive synergistic effects on soil resources when combined with

other Federal, state, local, and private restoration efforts (Table 5.6).

5.1.8 Alternative 8

5.1.8.1 Direct

Direct impacts of Alternative 8 on soils and substrate would be similar to those of

Alternative 2, but to a lesser degree. Implementation of Alternative 8 would result in 50

acres of swamp, 24 acres of fresh marsh, 125 acres of intermediate marsh, and 121 acres

of brackish marsh being directly converted to open water. Alternative 8 would also result

in 23 acres of swamp being converted to upland (levee). These direct impacts would be

the result of dredge features CD1, CD6, CD7, ED3, and ED6 and levee features CLV1

and CLV2. 41 acres of temporary impacts to open water and uplands due to temporary

work areas would also occur (Table 5.2).

5.1.8.2 Indirect

Indirect impacts of Alternative 8 on soils and substrate would be similar to those of

Alternative 2, but to a lesser degree. Alternative 8 would reduce land loss in the project

area from 101,570 acres to 100,581 acres, thus preventing 989 acres of emergent marsh

habitat from being converted to open water over the 50-year period of analysis.

Alternative 8 would generate 1,214 AAHUs (Figure 5.8).

5.1.8.3 Cumulative

Alternative 8 would have positive synergistic effects on soil resources when combined

with other Federal, state, local, and private restoration efforts (Table 5.6). Implementing

Alternative 8 would contribute to reducing regional rates of marsh soil loss by an

estimated 989 net acres over the 50-year period of analysis.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.2. Average Annual Habitat Units Associated with Implementation of Alternative 2 as Compared to No Action.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.3. Average Annual Habitat Units Associated with Implementation of Alternative 3 as Compared to No Action.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.4: Average Annual Habitat Units Associated with Implementation of Alternative 4 as Compared to No Action

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.5. Average Annual Habitat Units Associated with Implementation of Alternative 5 as Compared to No Action.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.6. Average Annual Habitat Units Associated with Implementation of Alternative 6 as Compared to No Action.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.7. Average Annual Habitat Units Associated with Implementation of Alternative 7 as Compared to No Action.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.8. Average Annual Habitat Units Associated with Implementation of Alternative 8 as Compared to No Action.

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5.2 Hydrology

5.2.1 Flow and Water Levels

5.2.1.1 No Action Alternative (Future without Project Conditions)

Building of the Atchafalaya River delta would continue to impact stages on the Lower

Atchafalaya River. As stages increase, the flow passing through the Bayou Lafourche

ridge in the GIWW would increase. Areas hydraulically isolated from the GIWW would

continue to be isolated.

Monthly averaged flows along the GIWW would range from over 700 cfs to 28,000 cfs.

These flows would generally decrease from west to east. The largest loss of flow would

continue to be through the HNC, with monthly averaged flows ranging from 2,500 to

7,000 cfs. At times, flow reversals would occur throughout the project area.

Flow would enter and leave the Lake Boudreaux basin through Bayou Dulac, Robinson

Canal, and Boudreaux Canal. Bayou Dulac monthly averaged flows would range

between 50 and 400 cfs. Robinson monthly averaged flows would be fairly steady near

1,500 cfs with higher monthly averaged flows near 1,700 cfs from March through June.

Boudreaux Canal monthly averaged flows would be fairly steady around 500 cfs with

higher monthly averaged flows near 700 cfs from March through June.

Monthly averaged flows into Grand Bayou would range between 0 and 575 cfs.

Stages within the project area would be tidally driven with effects from the Atchafalaya

River. Over the project life, water surface elevations would increase by at least 0.46 feet

due to sea level rise. This increase could be as much as 2.29 feet if the high rate of sea

level rise occurs.

5.2.1.2 Alternative 2 (NER Plan and RP)

5.2.1.2.1 Direct

Monthly averaged flows in the GIWW west of Grand Bayou would generally increase

with Alternative 2. The increase would range from 0 to 20 percent west of Houma and

could be as much as 50 percent east of Houma. These increases stop as the GIWW

reaches Grand Bayou. The additional flow through Grand Bayou would cause the flow

through Larose to reduce by as much as 50 percent. Generally, the largest changes in

flow would be seen during high Atchafalaya stages and the smallest during low stages.

Southeastern Penchant basin marshes would experience a monthly averaged flow

increase ranging from 100 to 3,000 cubic feet per second (cfs). Operation of the HNC

lock for environmental purposes would increase this flow benefit by an additional 300 to

1,000 cfs. Flow through Grand Pass would be reduced by 10 to 40 percent. High and

low increases would correspond with high and low Atchafalaya River stage, respectively.

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Monthly averaged flow introduced to the Lake Boudreaux basin through the newly

dredged channels on the west side of the basin would range from 100 to 700 cfs. With

the closure of Robinson Canal and the construction of the marsh berm features within the

basin, the monthly averaged flows in Boudreaux Canal would increase approximately 50

percent year round. High and low increases would correspond with high and low

Atchafalaya River stage, respectively.

Monthly averaged flow increases into the Grand Bayou basin would range from 0 to

2,700 cfs throughout the year. High and low increases would correspond with high and

low Atchafalaya River stage, respectively.

Stage impacts in the western region of the project area would be limited to the

southeastern portion. Impacts of 0.1 to 0.2 feet would be seen from March to September

with the highest seen in July. These impacts would be attributed to the reduced capacity

of Grand Pass due to feature WW2 and from increased inflow to this area from feature

WD2.

In the central region of the project area stage impacts would be limited to the Lake

Boudreaux basin. Stage impacts would vary between 0.1 and 0.3 feet from March to

September, with the highest seen in July. These impacts would be attributed to the

increased flow into the basin through the culverts and dredged channels connecting the

Boudreaux basin to the HNC and from the closure of Robinson Canal.

In the eastern region of the project area, impacts of up to 0.1 feet would be seen in the

Grand Bayou basin. These impacts would vary in duration throughout the basin, with

longer duration at the northern end, south of highway 24. Impacts ranging from March

through September would be the longest in this portion of the project area. Stage

reductions of up to 0.2 feet would also be seen along the GIWW in the western portion of

the project area. These too would be seen from March to September with the largest

reductions in July. Short duration impacts near the plug in Cutoff Canal would be as

much as 0.4 feet. These impacts would be highly localized to the area north of Bayou

Pointe au Chien to Grand Bayou.

5.2.1.2.2 Indirect

By reducing monthly averaged flows passing to the east into the Barataria Basin there

may be impacts in northern portions of the Barataria Basin. This flow deficit may be

counteracted through modified operation of the Davis Pond diversion.

5.2.1.2.3 Cumulative

Cumulative impacts include the construction and operation of other federal, state, local,

and private projects that modify the hydrology of the project area. Changes to the

operation of the Old River Control Structure and Davis Pond Diversion could both

beneficially affect the hydrology within the project area. The Small Bayou Lafourche

Reintroduction project (LCA) could increase flows to the Grand Bayou area. The

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Maintain Land Bridge between Caillou Lake and Gulf of Mexico project (LCA) could

decrease saltwater flows into the western part of the LCA-ARTM study area. The Avoca

Island Diversion and Land Building project (CWPPRA) could increase flows in the

Penchant marshes and in the GIWW. The GIWW Bank Restoration project (CWPPRA)

could increase easterly flows in the GIWW.

5.2.1.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, with the following exceptions.

With feature WS4, the diversion through the Avoca Island Levee, monthly averaged

flows throughout the project area would be increased by 0 to 2 percent with the higher

increases during low Atchafalaya River stage periods.

Stage impacts in the western region of the project area would extend through much of the

Penchant basin. Impacts of up to 0.1 feet throughout the Penchant basin and into Bayou

Boeuf and Lake Palourde would be seen in July and August. Impacts of 0.1 to 0.2 feet

would be seen in the southeast portion of the Penchant basin from March to September

with the highest seen in July. These impacts would be attributed to the reduced capacity

of Grand Pass due to feature WW2, the weir structure across Grand Pass, and from

increased inflow to this area from feature WD2, dredging of Carencro Bayou.

Stage impacts associated with structure WS4 would be limited to stages below the start of

damages in Amelia, LA. The operation of WS4 would use the correlation curve relating

the water surface elevation in Amelia to the Lower Atchafalaya River stage at Morgan

City, LA developed by USACE New Orleans district. This structure would not cause any

damages in addition to those that would occur with the current backwater flood damage

reduction system.

5.2.1.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, with the following exceptions.

Monthly averaged flow impacts along the GIWW will increase due to feature ES2, the

pump station connecting the GIWW to Grand Bayou. The magnitude of increase would

be larger closer to Grand Bayou. Larger flow increases would occur during low

Atchafalaya River stages. A monthly averaged flow reversal would occur on the GIWW

at Larose between the months of August and January.

Monthly averaged flow increases to the Lake Boudreaux basin would decrease by

approximately 50 percent during low Atchafalaya stages. The increase would be

maintained during higher stages.

Flow into the Grand Bayou basin would be a constant 4,000 cfs throughout the year.

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Stage impacts in the western region of the project area would be limited to the

southeastern portion. Impacts of 0.1 to 0.2 feet would be seen from March to September

with the highest seen in July. These impacts would be attributed to the reduced capacity

of Grand Pass due to feature WW2, the weir structure across Grand Pass, and from

increased inflow to this area from feature WD2, dredging of Carencro Bayou.

Stage impacts for Alternative 4 would be similar to Alternative 2 for the central portion

of the project area.

In the eastern portion of the project area, stage impacts would range from 0.0 to 0.3 feet

in the Grand Bayou basin. As with Alternative 2, these impacts would be largest in the

northern end of the Grand Bayou basin and fade to 0.0 feet in the southern portions of the

basin. The largest of these impacts would be seen between September and February.

Stage reductions of 0.2 feet would be seen along the GIWW from Company Canal to

Larose. Additional reductions up to 0.1 feet would be seen as far away as the HNC to the

west. Reductions to the east of Larose would also be likely, but were not quantified.

5.2.1.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, with the following additions.

Monthly averaged flow impacts would generally match Alternative 4. Feature WS4

would increase monthly averaged flows throughout the project area by an additional 0 to

2 percent with the higher increases during low Atchafalaya River stage periods.

Stage impacts in the western region of the study area would extend through much of the

Penchant basin. Impacts of up to 0.1 feet throughout the Penchant basin and into Bayou

Boeuf and Lake Palourde would be seen in July and August. Impacts of 0.1 to 0.2 feet

would be seen in the southeast portion of the Penchant basin from March to September

with the highest seen in July. These impacts would be attributed to the reduced capacity

of Grand Pass due to feature WW2 and from increased inflow to this area from feature

WD2.

Stage impacts associated with structure WS4, the diversion through the Avoca Island

levee, would be limited to stages below the start of damages in Amelia, LA. The

operation of WS4 would use the correlation curve relating the water surface elevation in

Amelia to the Lower Atchafalaya River stage at Morgan City, LA developed by USACE

New Orleans district. This structure would not cause any damages in addition to those

that would occur with the current backwater flood damage reduction system.

Stage impacts for Alternative 5 would be similar to Alternative 2 for the central portion

of the project area.

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In the eastern portion of the study area, stage impacts would range from 0.0 to 0.3 feet in

the Grand Bayou basin. As with Alternative 2, these impacts would be largest in the

northern end of the Grand Bayou basin and fade to 0.0 feet in the southern portions of the

basin. The largest of these impacts would be seen between September and February.

Stage reductions of 0.2 feet would be seen along the GIWW from Company Canal to

Larose. Additional reductions up to 0.1 feet would be seen as far away as the HNC to the

west. Reductions to the east of Larose would also be likely, but were not quantified.

5.2.1.6 Alternative 6

Flow benefits for Alternative 6 would generally be seen along the GIWW corridor. This

alternative would not provide flow benefits to the southeast portions of the Penchant

basin. Since no new connections would be made to the Lake Boudreaux basin, there

would be no flow impact. The Grand Bayou basin would benefit from monthly averaged

flow increases between 0 and 1,500 cfs. Monthly averaged flow changes on the GIWW

would range between increases and decreases of 5 percent, with the maximum increase

during low Atchafalaya River stages.

Stage impacts in the western region of the study area would extend through much of the

Penchant basin. Impacts of up to 0.1 feet throughout the Penchant basin and into Bayou

Boeuf and Lake Palourde would be seen in July and August. There would be no impacts

to the southeastern portions of the Penchant basin.

Stage impacts associated with structure WS4, the diversion through the Avoca Island

levee, would be limited to stages below the start of damages in Amelia, LA. The

operation of WS4 would use the correlation curve relating the water surface elevation in

Amelia to the Lower Atchafalaya River stage at Morgan City, LA developed by USACE

New Orleans district. This structure would not cause any damages in addition to those

that would occur with the current backwater flood damage reduction system.

There would be no stage impacts for Alternative 6 for the central portion of the project

area.

In the eastern region of the project area, impacts of up to 0.1 feet would be seen in the

Grand Bayou basin. These impacts would vary in duration throughout the basin, with

longer duration at the northern end, south of highway 24. Impacts ranging from March

through September would be the longest in this portion of the project area. Stage

reductions of up to 0.2 feet would also be seen along the GIWW in the western portion of

the project area. These too would be seen from March to September with the largest

reductions in July.

5.2.1.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

Alternative 1, with the following exceptions.

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Operations of the HNC lock would reduce the flow in the HNC; this would be magnified

south of the lock. It would increase flow away from the HNC through Bayou Grand

Caillou, Falgout Canal, and Bayou Dulac and the marshes surrounding the HNC.

5.2.1.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, with the following exceptions.

Monthly averaged flow increases into the southeastern Penchant basin would not occur.

The Grand Bayou basin monthly averaged flow increase would be limited to 2300 cfs.

There would be no stage impacts in the western portion of the study area.

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5.2.2 Sedimentation and Erosion

5.2.2.1 No Action Alternative (Future without Project Conditions)

Building of the Atchafalaya River delta would continue to impact stages on the Lower

Atchafalaya River. As stages increase, eastward flows along the GIWW would increase,

carrying with them suspended sediments. These sediments would be distributed through

the project area according to the flow patterns we see today. Southernmost portions of

the Boudreaux basin would continue to be the only areas to receive suspended sediments

from the GIWW. In the Grand Bayou basin, a small portion of suspended sediments that

arrive through the GIWW would be distributed to the marshes to the east of Grand

Bayou.

Bank lines of major navigation channels would continue to erode, depositing sediments

in the channels. The need for periodic maintenance dredging would continue.

Land building sediments would not enter the project area naturally on a large scale.

Federal, state, and local programs may beneficially use dredged materials within the

project area. Construction of channels and maintenance of existing channels would be

sources from within the project area. Additionally, sediment may be brought from

sources outside the project area.

5.2.2.2 Alternative 2 (NER Plan and RP)

5.2.2.2.1 Direct

Sediments from enlarged and newly created channels would be used beneficially within

the project area. During construction, these sediments would be placed into marsh

creation areas.

Suspended sediment loads to receiving areas would be increased, but not enough to

provide calculable benefits. The southeast portions of the Penchant basin would receive

additional suspended sediment loads due to feature WD2. Northern Boudreaux Basin

would receive suspended sediments brought through the GIWW to the HNC. These

sediments would be distributed throughout the Boudreaux Basin. An increased amount

of suspended sediment would reach the Grand Bayou basin. These sediments would be

distributed to the marshes east of Grand Bayou with a much smaller portion exiting the

basin through Cutoff Canal due to feature EP7. Operations of the HNC lock would

increase suspended sediments to the marshes between the HNC and Bayou Du Large.

There would be a decreased suspended sediment load south of the HNC lock.

5.2.2.2.2 Indirect

Reduction of sediment carried into the Barataria Basin through the Bayou Lafourche

Ridge may have incalculable impacts. Secondary erosion along channels receiving

increased flows may occur, resulting in sedimentation and shoaling in area waterways.

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5.2.2.2.3 Cumulative

Bank line protection constructed by other Federal, state, local and private projects would

cause a reduction in bank line erosion. These projects would also help convey suspended

sediments to the Boudreaux and Grand Bayou basins.

5.2.2.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a slightly greater extent.

5.2.2.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2. Impacts to the Boudreaux basin would be to a lesser extent as this

alternative does not include bank line stabilization. In the Grand Bayou basin, the

beneficial impacts would be greater due to the pumping of water from the GIWW year

round.

5.2.2.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater extent due to the pumping of water from the GIWW year

round.

5.2.2.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser extent.

5.2.2.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

Alternative 2, but would affect a much smaller area. The area affected would be in the

vicinity of the HNC lock. Both the Boudreaux and Grand Bayou basins would not see

much, if any, change from Alternative 1.

5.2.2.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but would not affect the southeastern portions of the Penchant basin.

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5.3 Water Quality and Salinity

5.3.1 No Action Alternative (Future without Project Conditions)

Without the proposed actions of the project, the coastal plain of Louisiana would still be

affected by activities, natural and man-influenced, that would have both beneficial and

detrimental effects to water quality conditions. Some of these activities include other

Federal, state, local, and private restoration efforts such as CWPPRA, USACE ecosystem

restoration projects, various NRCS programs (e.g., Coastal Wetlands Restoration

Program), and LDNR projects; state and local water quality management programs;

national level programs to address hypoxia in the northern Gulf of Mexico; the continued

erosion/subsidence of the coast; oil and gas development; industrial, commercial, and

residential development; and Federal, state, and municipal navigation and flood-damage

reduction projects. The future quality of Louisiana’s coastal waters depends on a

responsible, watershed approach to managing these activities.

There are a number of present and future activities that would continue to occur without

the proposed actions of the project and would affect surface water quality conditions in

the coastal plain of Louisiana. The cumulative impact of these activities without the

project is discussed below.

Passage of the Federal Water Pollution Control Act (FWPCA) in 1948 and its

amendments including the CWA and the Water Quality Act of 1987 and the

establishment of state and Federal environmental protection agencies resulted in water

pollution control regulations, including:

• The National Pollutant Discharge Elimination System (NPDES) permit program

controls water pollution. In 1997 the USEPA granted NPDES delegation to

LDEQ, which is known as the Louisiana Pollutant Discharge Elimination System

(LPDES).

• LDEQ’s Nonpoint Source Pollution Program is continuing to implement

watershed initiatives to address nonpoint source pollution sources such as

agriculture, home sewage treatment, hydromodification, urban runoff,

construction activities, and resource extraction.

• LDNR’s Coastal Nonpoint Pollution Program is responsible for identifying Best

Management Practices (BMPs) appropriate for all applicable pollutant source

categories and carrying out initiatives of public education, technical assistance,

and development of enforcement protocols.

• Total Maximum Daily Loads (TMDLs)-Section 303(d) of the CWA requires

states to identify, list, and rank for development of TMDLs waters that do not

meet applicable water quality standards after implementation of technology-based

controls.

• Barataria-Terrebonne National Estuary Program (BTNEP) is a coalition of

government, private, and commercial interests active in collecting/publishing

information, as well as educating the public to protect the Barataria and

Terrebonne Basins.

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• The USEPA-formed Hypoxia Task Force is leading a national task force to

address hypoxia in the northern Gulf of Mexico, which is attributed to the

excessive nutrients in the Mississippi – Atchafalaya River Basin

The programs discussed above would continue to develop or remain in place with or

without the proposed project features to ensure protection of Louisiana’s public health

and natural resources. Water quality conditions would likely improve with the programs

in place. Other efforts that would probably improve water quality conditions would be

the present and future Federal, state, local, and private ecosystem restoration projects.

However, some activities that may potentially have negative effects on water quality

would also continue to occur with or without the proposed project.

• Industrial, commercial, and residential development along the coast. With this

activity comes increased point and nonpoint source pollution from sources such as

wastewater treatment facilities and urban runoff from new development. Also,

activities associated with maintaining and improving navigation along the coast

would continue to occur.

• Flood–damage reduction projects would continue to be planned, designed, and

constructed especially in areas highly susceptible to flood damages due to

hurricanes and tropical storm events. With these activities, more alterations to the

hydrology of the coast would potentially occur, leading to areas of degraded water

quality. Some projects, such as the Morganza to the Gulf Hurricane Protection

Project, are incorporating resource sustainable design techniques that may aid in

protecting significant resources such as surface waters of the state.

• The most notable activity that would continue to occur without the proposed LCA

Plan is the ongoing erosion/subsidence or land loss of the coastal areas. This

would continue to unearth the expansive oil and gas infrastructure along the coast

of Louisiana. This would be a precarious situation, especially during storm events

and within navigable waterways. Exposed pipelines are vulnerable to navigation

vessels striking them, which could lead to discharges into the Gulf of Mexico as

well as other coastal water bodies. In the event of discharges, extensive

ecological damage would probably occur. The owner(s) of the infrastructure

could incur expensive fines and cleanup costs and vessel operators could be

seriously injured. There are other forms of infrastructure that could potentially be

exposed due to coastal erosion including wastewater collection systems and other

commercial industry related systems.

Hydraulic modeling was utilized to project changes in hydrology and associated changes

in water quality in the project area over the 50-year period of analysis. Model results

were utilized in the Wetland Value Assessment model to project land loss impacts.

Under Future without Project Conditions, the flotant marshes within the Penchant Basin

would continue to deteriorate due to excessive backwater flooding events from the

Atchafalaya River. Modeled salinity values show no change in these areas over the 50-

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year period of analysis. Land change projections over the period of analysis show

increases in land area of approximately 5% (see Section 5.6 below for discussion on

impacts to vegetation). However, land loss analysis in this area is difficult due to the

presence of floating vegetation. It is believed that these marshes are actually

deteriorating due to excessive backwater flooding events from the Atchafalaya River and

will continue as such into the future. The intermediate and brackish marshes in the

southeastern Penchant area are expected to continue to deteriorate due to saltwater

intrusion, relative sea level rise, and lack of freshwater, sediment and nutrient delivery.

Modeled average annual salinity values show slight increases of 0.1 to 0.4 ppt over the

period of analysis. Land change projections over the period of analysis show decreases

in land area of approximately 35%. The fresh, intermediate, brackish, and saline marshes

in the Central – Lake Boudreaux Area are expected to continue to deteriorate due to

saltwater intrusion, relative sea level rise, and lack of freshwater, sediment and nutrient

delivery. Modeled average annual salinity values in this region show increases of 0.3 to

1.2 ppt over the period of analysis. Land change projections over the period of analysis

show decreases in land area of approximately 35%, with several areas converting

completely to open water. The fresh, intermediate, brackish, and saline marshes within

the East – Grand Bayou Area are expected to continue to deteriorate due to saltwater

intrusion, relative sea level rise, and lack of freshwater, sediment and nutrient delivery.

Modeled average annual salinity values show increases of 0.1 to 1.7 ppt over the period

of analysis. Land change projections over the period of analysis show decreases in land

area of approximately 49%, with several areas converting completely to open water.

5.3.2 Alternative 2 (NER Plan and RP)

5.3.2.1 Direct

Long-term direct impacts to water quality associated with implementation of Alternative

2 would primarily be associated with changes in the salinity and nutrient concentrations

of receiving waters. These impacts are the primary drivers in the calculation of Average

Annual Habitat Units for each Alternative. Average annual changes in salinity due to

implementation of Alternative 2, as compared to the No Action Alternative, can be found

in Figure 5.10. Changes in isohaline lines (lines that connect points of equal salinity)

during low Atchafalaya flows, representing dry season conditions, can be found in Figure

5.19. Changes in isohaline lines during high Atchafalaya flows, representing wet season

conditions, can be found in Figure 5.20. AAHUs associated with Alternative 2 can be

found in Figure 5.2. The largest decreases in average annual salinity concentrations due

to Alternative 2 would be expected to occur in the southeast Penchant marshes, in Lake

Boudreaux, and around Grand Bayou. The largest increases in salinity would be

expected along the HNC. The most notable change in isohaline lines with project

implementation during low Atchafalaya flows would be a shift of the 5 ppt isohaline line

from the north side of Lake Mechant and Lost Lake to the south side. During high

Atchafalaya flows, however, the changes in isohaline lines are minor in the Lake

Mechant/Lost Lake area, but are more noticeable in the Lake Boudreaux and Grand

Bayou areas, as the 5 ppt isohaline line is pushed further into these areas. For data on

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salinity changes over the entire period of analysis, see Annex 2 to Engineering Appendix

L.

Total suspended solids concentrations, and associated trace metals, of receiving waters

would at times increase with Alternative 2. However, due to the distance of the receiving

waters from the Atchafalaya River, impacts from suspended sediments are expected to be

minor and were not considered in the calculation of AAHUs.

Short-term direct impacts to water quality could also result from construction activities

associated with Alternative 2. Impacts associated with construction of features could

include: increased total suspended solids and turbidity, increased dissolved nutrient

levels, mobilization of existing contaminants in sediments, and decreases in dissolved

oxygen levels. These impacts would be minimized, as much as practicable, through

implementation of appropriate Best Management Practices.

The introduction of agrochemicals into the study area from any of the restoration

opportunities could be a management issue. The primary source of agrochemicals into

the study area would be from the corn belt of the mid-continent United States. Currently,

agricultural chemicals, primarily herbicides and fertilizers, are being introduced into the

study area from the Mississippi/Atchafalaya River systems. Of particular concern is the

effect on floating maidencane marshes (such as those in the Penchant Basin). River

water may lead to accelerated decomposition of floating marsh root mats, making them

more susceptible to erosion from tides, storms, and hurricanes (Swarzenski et al. 2008).

Monitoring efforts and adaptive management actions would be key to addressing

potential impacts.

5.3.2.2 Indirect

In addition to directly affecting salinity patterns in the receiving waters, Alternative 2

could have indirect effects on salinity patterns in the project area. Changes in marsh

health, stratification and mixing patterns, and flow patterns in the project due to project

features could have a minor effect on tidal flows which could affect salinities. Secondary

erosion along channels receiving increased flows may occur with implementation of

Alternative 2, resulting in localized increases in turbidity, sedimentation, and shoaling in

area waterways.

Alternative 2 could have negative effects on plankton resources by potentially increasing

noxious algal blooms associated with diversion flows and associated nutrients which, in

turn, could impact the water quality of receiving waters.

5.3.2.3 Cumulative

With implementation of Alternative 2, the coastal plain of Louisiana would be affected

by other activities and programs that would have both cumulatively beneficial and

detrimental effects on water quality conditions. Some of these past, present, and

foreseeable future activities include state and local water quality management programs;

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national level programs to address hypoxia in the northern Gulf of Mexico; oil and gas

development; industrial, commercial, and residential development; and Federal, state, and

local navigation and flood-damage reduction projects.

The direct and indirect impacts discussed previously would cumulatively impact water

quality conditions along with other coastal activities. The proposed features would

independently elevate water quality constituents such as nutrients and sediment in

receiving areas. Other activities such as development would potentially increase point

and nonpoint source pollution in the same water bodies, thereby causing a cumulative

effect. However, continued state and Federal programs tasked with regulating water

quality impacts would benefit the same water bodies. It is not possible to quantify the

effects to water bodies from all coastal activities. However, after project implementation,

monitoring and analysis will be conducted to better assess the effects (see Adaptive

Management and Monitoring Plan, Appendix I).

5.3.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree. Average annual changes in salinity due to

implementation of Alternative 3, as compared to the No Action Alternative, can be found

in Figure 5.11. Projected isohaline lines can be found in Figures 5.21 and 5.22. AAHUs

associated with Alternative 3 can be found in Figure 5.3.

5.3.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree. With the inclusion of the pump station at Grand

Bayou, freshening of the marshes in the Grand Bayou basin would be much more

pronounced. The pump station would also adversely impact isohalines in the Barataria

Basin (see Figure 5.23) and would force saltwater up Bayou Lafourche. Average annual

changes in salinity due to implementation of Alternative 4, as compared to the No Action

Alternative, can be found in Figure 5.12. Projected isohaline lines can be found in

Figures 5.23 and 5.24. AAHUs associated with Alternative 4 can be found in Figure 5.4.

5.3.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater degree. With the inclusion of the pump station at Grand

Bayou, freshening of the marshes in the Grand Bayou basin would be much more

pronounced. The pump station would also adversely impact isohalines in the Barataria

Basin (see Figure 5.25) and would force saltwater up Bayou Lafourche. Average annual

changes in salinity due to implementation of Alternative 5, as compared to the No Action

Alternative, can be found in Figure 5.13. Projected isohaline lines can be found in

Figures 5.25 and 5.26. AAHUs associated with Alternative 5 can be found in Figure 5.5.

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5.3.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser degree. Average annual changes in salinity due to

implementation of Alternative 6, as compared to the No Action Alternative, can be found

in Figure 5.14. Projected isohaline lines can be found in Figures 5.27 and 5.28. AAHUs

associated with Alternative 6 can be found in Figure 5.6.

5.3.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

Alternative 2, but to a lesser degree. Average annual changes in salinity due to

implementation of Alternative 7, as compared to the No Action Alternative, can be found

in Figure 5.15. Projected isohaline lines can be found in Figures 5.29 and 5.30. AAHUs

associated with Alternative 7 can be found in Figure 5.7.

5.3.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree. Average annual changes in salinity due to

implementation of Alternative 8, as compared to the No Action Alternative, can be found

in Figure 5.16. Projected isohaline lines can be found in Figures 5.31 and 5.32. AAHUs

associated with Alternative 8 can be found in Figure 5.8.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.9. Predicted Average Annual Salinity Values (ppt) for the No Action Alternative in 2025.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.10. Predicted Changes in Average Annual Salinity Values (ppt) in 2025 as a Result of Implementation of Alternative 2. Numbers representchanges in comparison to the No Action Alternative. Negative values represent a decrease in salinity.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.11. Predicted Changes in Average Annual Salinity Values (ppt) in 2025 as a Result of Implementation of Alternative 3. Numbers representchanges in comparison to the No Action Alternative. Negative values represent a decrease in salinity.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.12. Predicted Changes in Average Annual Salinity Values (ppt) in 2025 as a Result of Implementation of Alternative 4. Numbers representchanges in comparison to the No Action Alternative. Negative values represent a decrease in salinity.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.13. Predicted Changes in Average Annual Salinity Values (ppt) in 2025 as a Result of Implementation of Alternative 5. Numbers represent

changes in comparison to the No Action Alternative. Negative values represent a decrease in salinity.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.14. Predicted Changes in Average Annual Salinity Values (ppt) in 2025 as a Result of Implementation of Alternative 6. Numbers represent

changes in comparison to the No Action Alternative. Negative values represent a decrease in salinity.

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Figure 5.15. Predicted Changes in Average Annual Salinity Values (ppt) in 2025 as a Result of Implementation of Alternative 7. Numbers represent

changes in comparison to the No Action Alternative. Negative values represent a decrease in salinity.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.16. Predicted Changes in Average Annual Salinity Values (ppt) in 2025 as a Result of Implementation of Alternative 8. Numbers represent

changes in comparison to the No Action Alternative. Negative values represent a decrease in salinity.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.17. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages for the No Action Alternative in 2025.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.18. Predicted Locations of Isohaline Lines During High Atchafalaya Stages for the No Action Alternative in 2025.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.19. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 2.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.20. Predicted Locations of Isohaline Lines During High Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 2.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.21. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 3.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.22. Predicted Locations of Isohaline Lines During High Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 3.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.23. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 4.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.24. Predicted Locations of Isohaline Lines During High Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 4.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.25. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 5.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.26. Predicted Locations of Isohaline Lines During High Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 5.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.27. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 6.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.28. Predicted Locations of Isohaline Lines During High Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 6.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.29. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 7.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.30. Predicted Locations of Isohaline Lines During High Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 7.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.31. Predicted Locations of Isohaline Lines During Low Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 8.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.32. Predicted Locations of Isohaline Lines During High Atchafalaya Stages in 2025 as a Result of Implementation of Alternative 8.

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5.4 Air Quality

5.4.1 No Action Alternative (Future without Project Conditions)

Air quality would continue to be subject to institutional recognition and further

regulations. However, air quality in the study area would likely decline for the following

reasons: continued population growth, further commercialization and industrialization,

increased numbers of motor vehicles, and increased emissions from various engines.

These impacts would be coupled with the continued loss of Louisiana coastal wetland

vegetation that would no longer be available to remove gaseous pollutants. There would

likely be associated increases in respiratory ailments (such as asthma) in the human

populations. Nevertheless, air quality degradation is not anticipated to be a significant

problem in the project area under the No Action Alternative during the 50-year period of

analysis.

5.4.2 Alternative 2 (NER Plan and RP)

5.4.2.1 Direct

Direct impacts to ambient air quality would be temporary and localized, resulting

primarily from the emissions of construction equipment within the project area. It has

been the experience of the CEMVN that total emissions for each work item separately (or

even when all work items are summed) generally do not exceed the threshold limit

applicable to volatile organic compounds (VOC) for parishes where the most stringent

requirement (50 tons per year [49.38 metric tons per year] in serious non-attainment

parishes) is in effect. All five parishes in the project area are attainment areas and

therefore would not be subject to this requirement. Project emissions would be classified

as de minimus and no further action would be required. It is likely that indirect

emissions, if they occur, would be negligible. Additionally, these effects to air quality

would be temporary, and air quality would return to pre-construction conditions shortly

after the completion of construction activities.

5.4.2.2 Indirect

Principal indirect impacts would be related to the potential improvement in air quality

that increasing vegetated wetlands would provide. Improvement of air quality would

provide positive benefits for humans suffering from health problems such as asthma and

other respiratory problems.

Restoration of vegetated wetlands over the 50-year period of analysis would help to

improve air quality by reducing particulates and gaseous air pollutants. Studies of the

effects of common wetland plants on removing or reducing air pollution in the coastal

Louisiana area have yet to be done. However, it is reasonable to extrapolate from the

findings of researchers such as David J. Nowak (personal communication, David J.

Nowak, Project Leader, USDA Forest Service, Northeastern Research Station, 5 Moon

Library, SUNYCESF, Syracuse, New York) that the trees and vegetation in coastal

Louisiana would improve air quality. Hence, over the 50-year period of analysis, the

anticipated benefits to marshes in the project area from implementation of Alternative 2

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(3,220 AAHUs) should have a positive impact on air quality by removing gaseous and

particulate air pollutants.

5.4.2.3 Cumulative

Primary cumulative impacts would be the potential improvement of air quality due to the

removal of air pollutants by vegetation. Other cumulative impacts include the additive

effects of similar Federal, state, local, and private wetland restoration efforts that would

also contribute to reduction of air pollution, as well as other technological efforts such as

scrubbers on smoke stacks, more stringent emissions standards on motors, etc. From the

cumulative impacts perspective, this potential improvement in air quality by restoration

efforts would be in contrast to continued air pollution by other sources.

5.4.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree. Direct impacts from construction activities would

be increased slightly due to implementation of features WO2 and WS4. Indirect impacts

from benefits to marsh habitat would be slightly increased, as Alternative 3 would

generate 3,325 AAHUs over the 50-year period of analysis.

5.4.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree. Direct impacts would be greater due to the

construction and operation of the pump station at Grand Bayou (feature ES2). Indirect

impacts from benefits to marsh habitat would be greater, as Alternative 4 would generate

4,258 AAHUs over the 50-year period of analysis.

5.4.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater degree. Direct impacts would be greater due to the

construction of the Avoca Island diversion structure (WS4) and associated shoreline

protection (WO2) and due to construction and operation of the pump station at Grand

Bayou (ES2). Indirect impacts from benefits to marsh habitat would be greater, as

Alternative 5 would generate 4,719 AAHUs over the 50-year period of analysis.

5.4.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser degree. Direct impacts from construction of features would

be greatly reduced due to the lack of flow management features with Alternative 6.

Indirect impacts from benefits to marsh habitat would also be reduced, as Alternative 6

would generate 776 AAHUs over the 50-year period of analysis.

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5.4.7 Alternative 7

Direct impacts of Alternative 7 on air quality would be minor and short-term. Indirect

impacts from benefits to marsh habitat would be reduced in comparison to Alternative 2,

as Alternative 7 would generate 243 AAHUs over the 50-year period of analysis.

5.4.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree. Direct impacts from construction of features would

be greatly reduced due to the elimination of several features with Alternative 8. Indirect

impacts from benefits to marsh habitat would also be reduced, as Alternative 8 would

generate 1,214 AAHUs over the 50-year period of analysis.

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5.5 Noise

5.5.1 No Action Alternative (Future without Project Conditions)

Local and temporary noise impacts typically associated with human activities and

habitations such as car and truck traffic, operation of commercial and recreational boats,

water vessels, air boats, and other recreational vehicles; operation of machinery and

motors; and human residential-related noise (air conditioners, lawn mowers, etc.) would

likely continue to affect humans and animals in the study area.

5.5.2 Alternative 2 (NER Plan and RP)

5.5.2.1 Direct

Construction activities associated with implementing Alternative 2 would temporarily

increase the noise level in the project area. Because of the proximity of some of the

features to developed areas, there are a number of residential and commercial properties

that could be exposed to adverse impacts from construction noise. One construction

activity, pile driving, would be expected to create temporary noise impacts above 65 dBA

to sensitive receptors within 1,000 ft of the construction activity (see Table 5.3).

Assuming the worst case scenario of 101 dBA, as would be the case during pile driving,

all areas within 1,000 ft of the pile driving would experience noise levels exceeding 65

dBA. The use of pile drivers and other high level noise sources would likely be limited

to daylight hours, which would reduce the adverse impact of noise on surrounding land

uses. Pile driving is also limited in extent because it will only occur during construction

of features WW2, CC3, CC4, CC13, CC14, CC15, CS1, EC3, and EC5. However, pile

driving would occur within 100 ft of residential homes and approximately 115 residences

within 1,000 ft of these areas could experience noise disturbances greater than 65 dBA.

The remaining construction activities that do not include pile driving would not create

noise impacts above 65 dBA outside of 500 ft from the construction areas.

Approximately 230 residences would be within 500 ft of construction activities and could

experience sound impacts from general construction above 65 dBA.

Localized and temporary noise impacts would likely result in wildlife and fishery

resources temporarily leaving construction areas during construction activities. In some

instances, noise impacts may directly impact fish and wildlife species. These organisms

would generally avoid the construction area. However, tolerance of unnatural

disturbance varies among wildlife. Therefore identifying the key species of concern and

following feasible administrative and or engineering controls, determining and

implementing appropriate buffer zones, and implementing construction activity windows

will address these issues.

5.5.2.2 Indirect

It is anticipated that, in some instances, noise impacts may be an important issue for their

potential indirect effects on wildlife, such as disruption of normal breeding patterns.

Noise may temporarily cause some local fish and wildlife species to relocate during

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construction activities. However, indirect impacts due to noise are expected to be

localized, temporary, and minor in nature.

5.5.2.3 Cumulative

The cumulative impacts would principally be related to the potential short-term

disruption of human communities and fish and wildlife species along with similar

impacts by other Federal, state, local and private activities as well as other humaninduced noise disruptions.

5.5.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a slightly greater degree due to implementation of features WO2 and

WS4. Approximately 230 residences would be within 500 ft of construction activities

and could experience sound impacts from general construction above 65 dBA.

Approximately 115 residences within 1,000 ft of features included in Alternative 3 could

experience noise disturbances greater than 65 dBA due to pile driving.

5.5.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree due to the added temporary noise impacts of

construction of features EP8 and ES2. Approximately 235 residences would be within

500 ft of construction activities and could experience sound impacts from general

construction above 65 dBA. ES2 would require pile driving. Approximately 120

residences within 1,000 ft of features included in Alternative 4 could experience noise

disturbances greater than 65 dBA due to pile driving. ES2 would have additional longterm noise impacts due to the operation of the pump station. Four residences within 500

ft of the pump station could experience sound impacts from pump operation above 65

dBA.

5.5.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would be similar to Alternative

4, but to a slightly greater degree due to the added temporary noise impacts on fish and

wildlife from construction of features WO2 and WS4.

5.5.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a much lesser degree. Approximately 105 residences would be

within 500 ft of construction activities and could experience sound impacts from general

construction above 65 dBA. EC5 would require pile driving. 5 residences within 1,000

ft of EC5 could experience noise disturbances greater than 65 dBA due to pile driving.

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Table 5.3. Weighted (dBA) Sound Levels of Construction Equipment and Modeled Attenuation at

Various Distances1

Noise Source 50 ft 100 ft 200 ft 500 ft 1000 ft

Crane 81 75 69 61 55

Dump Truck 76 70 64 56 50

Compactor/Roller 83 77 71 63 57

Tractor 84 78 72 64 58

Excavator 81 75 69 61 55

Front end loader 79 73 67 59 53

Concrete

mixer/pump

truck

79 73 67 59 53

Dozer 82 76 70 62 56

Pile driver 101 95 89 81 75 1 The dBA at 50 ft is a measured noise emission. The 100- to 1000-ft results are modeled

estimates. Source: FHWA (2006), Highway Construction Noise Handbook.

5.5.7 Alternative 7

5.5.7.1 Direct

Direct impacts of Alternative 7 would be limited to noise impacts from modified

operation of the Houma Navigation Canal lock complex. Noise impacts of this

Alternative on human communities would be minor given that the feature is located in a

remote location. Noise impacts to fish and wildlife species would be intermittent, minor,

and temporary.

5.5.7.2 Indirect

Indirect impacts due to noise are expected to be localized, temporary, and minor in

nature.

5.5.7.3 Cumulative

The cumulative impacts would principally be related to the potential short-term

disruption of human communities and fish and wildlife species and similar impacts by

other Federal, state, local and private activities as well as other human-induced noise

disruptions.

5.5.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree. Approximately 75 residences would be within 500

ft of construction activities and could experience sound impacts from general

construction above 65 dBA. Approximately 115 residences within 1,000 ft of features

included in Alternative 8 could experience noise disturbances greater than 65 dBA due to

pile driving.

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5.6 Vegetation Resources

5.6.1 No Action Alternative (Future without Project Conditions)

Under the No Action Alternative, the fresh marshes in the western portion of the study

area would likely continue to receive increasing amounts of fresh water from the

Atchafalaya River. As the river’s delta enlarges, high water would be more likely to

escape laterally to the east and west. The acreage likely to receive the fresh water,

nutrients, and sediment from the Atchafalaya River would increase. The increase in fresh

water would likely encourage more submerged aquatic vegetation in open water areas.

Land loss rates in this area would likely remain low as subsidence would be counteracted

largely by increased freshwater flows and sediment arriving from the Atchafalaya River

and stimulated marsh growth. Land loss in the Penchant basin has been highest around

Jug Lake. Several CWPPRA projects in the area are being implemented to address this

elevated loss rate: Penchant Basin Natural Resources Plan (TE-34), South Lake DeCade

Freshwater Introduction (TE-39), and North Lake Mechant Landbridge Restoration (TE44). However, it is anticipated that land loss near this location would continue.

In the central and eastern subareas, wetlands would continue to be lost at an annual rate

of about what has been measured from 1985-2008 because of subsidence, inundation of

marsh plants, and subsequent erosion in brackish and saline marshes. As these marshes

disappear, salt water would begin to move northward more rapidly, further stressing fresh

and intermediate marshes. These marshes would likely not tolerate the increasing salinity

well and would probably not convert to brackish marsh because the soils would be

comprised of too much organic matter. Research by Lessmann et al. (1997), and McKee

and Mendelssohn (1989) indicate these marshes would be very susceptible to the

deleterious effects from the sudden influx of salt water from a tidal surge associated with

a hurricane.

For this study, 1985-2008 land loss data for each of the subareas was utilized to project

future conditions. In a few instances, land loss rates were adjusted to account for

anticipated changes due to recently completed or authorized projects or other conditions

which rendered the predicted values inaccurate. The actual rates used can be found in

Figure 5.33. These land loss rates were applied to project area polygons to produce

annual acreages lost from each subarea. Using the annual acreage figure resulted in a

linear trend of marsh loss through the 50-year period of analysis. Projections started with

the acreage from 2008, the latest complete year of data available during analyses. As can

be seen in Figure 5.33, areas of highest land loss are concentrated in the southeastern

portion of the project area.

The overall habitat value and acreage of remaining wetlands would decline with the No

Action alternative. WVA analysis predicted that approximately 102,000 acres or 18

percent of remaining vegetated wetlands in the study area would be lost over the 50-year

period of analysis. Several of the subareas (A7, C3, C6, C7, C8, C10, D3, E2, E3, E4,

F2, G5, and G6) are predicted to lose all emergent wetlands before the end of the 50-year

period of analysis.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.33. Land Gain/Loss Rates in the Project Area – percent per year based on 1985 to 2008 rates and 1985 acreage (based on Barras et al. 2008and Barras 2009). Negative numbers indicate land loss.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 5.4. Summary of Wetland Value Assessment Variables Associated with each Alternative and Target Year*.

No Action Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 Alt 8

Var. TY0 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50

Palmetto/Creole Bayou Area – Fresh Marsh - 57,585 acres

V1 87.0 86.9 86.3 83.7 86.9 86.3 83.7 86.9 86.3 83.7 86.9 86.3 83.7 86.9 86.3 83.7 86.9 86.3 83.7 86.9 86.3 83.7 86.9 86.3 83.7V2 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0

V3-1 80.0 79.0 75.0 58.0 79.0 75.0 58.0 79.0 75.0 58.0 79.0 75.0 58.0 79.0 75.0 58.0 79.0 75.0 58.0 79.0 75.0 58.0 79.0 75.0 58.0V3-2 20.0 21.0 25.0 42.0 21.0 25.0 42.0 21.0 25.0 42.0 21.0 25.0 42.0 21.0 25.0 42.0 21.0 25.0 42.0 21.0 25.0 42.0 21.0 25.0 42.0V3-3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

V4 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0V5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

Lake Pagie, A6, A7 Area – Brackish Marsh - 59,460 acres

V1 26.5 26.1 22.6 9.6 27.7 26.0 23.9 27.7 26.0 24.2 27.7 26.0 23.8 27.7 26.0 24.0 27.5 24.0 12.1 27.5 24.0 12.1 27.5 24.0 11.8V2 40.0 40.0 37.0 24.0 45.0 45.0 40.0 45.0 45.0 40.0 45.0 45.0 40.0 45.0 45.0 43.0 40.0 37.0 24.0 40.0 37.0 28.0 35.0 34.0 28.0

V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-2 10.0 7.0 0.0 0.0 10.0 7.0 0.0 10.0 7.0 0.0 10.0 7.0 0.0 10.0 7.0 0.0 10.0 6.0 0.0 10.0 6.0 0.0 10.0 6.0 0.0V3-3 13.0 17.0 15.0 0.0 15.0 17.0 25.0 15.0 17.0 25.0 15.0 17.0 25.0 15.0 17.0 25.0 15.0 14.0 0.0 15.0 14.0 0.0 15.0 14.0 0.0V3-4 32.0 32.0 44.0 0.0 34.0 31.0 26.0 34.0 31.0 28.0 34.0 31.0 25.0 34.0 31.0 27.0 33.0 30.0 14.0 33.0 30.0 14.0 33.0 30.0 12.0V3-5 45.0 44.0 41.0 100.0 41.0 45.0 49.0 41.0 45.0 47.0 41.0 45.0 50.0 41.0 45.0 48.0 42.0 50.0 86.0 42.0 50.0 86.0 42.0 50.0 88.0

V4 10.0 10.0 9.0 2.0 10.0 10.0 9.0 10.0 10.0 9.0 10.0 10.0 9.0 10.0 10.0 9.0 10.0 9.0 3.0 10.0 9.0 3.0 10.0 9.0 3.0V5 2.9 2.9 2.9 2.7 2.2 1.9 1.6 2.2 1.9 1.6 2.6 2.5 1.9 2.5 2.4 1.9 2.9 2.8 2.5 2.9 2.8 2.6 3.2 3.1 2.9V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

G2, G3, G6 Area – Brackish Marsh - 38,269 acres

V1 45.6 44.8 37.5 13.6 44.4 39.2 25.7 44.4 39.2 25.9 44.9 44.6 51.6 44.9 44.6 51.6 44.4 38.1 18.6 44.8 37.5 13.6 44.4 38.9 23.9V2 3.0 3.0 2.0 0.0 5.0 5.0 2.0 5.0 5.0 2.0 15.0 14.0 12.0 15.0 14.0 12.0 5.0 5.0 2.0 3.0 2.0 0.0 5.0 5.0 2.0

V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 0.0 0.0 0.0 0.0V3-2 20.0 20.0 12.0 0.0 20.0 10.0 0.0 20.0 10.0 0.0 20.0 13.0 0.0 20.0 13.0 0.0 20.0 10.0 0.0 19.0 0.0 0.0 20.0 13.0 0.0V3-3 42.0 39.0 34.0 0.0 40.0 39.0 15.0 40.0 39.0 15.0 40.0 40.0 38.0 40.0 40.0 38.0 40.0 34.0 0.0 42.0 30.0 0.0 38.0 36.0 17.0V3-4 38.0 41.0 41.0 24.0 40.0 51.0 67.0 40.0 51.0 68.0 40.0 47.0 57.0 40.0 47.0 57.0 40.0 56.0 61.0 38.0 50.0 24.0 42.0 40.0 47.0V3-5 0.0 0.0 13.0 76.0 0.0 0.0 18.0 0.0 0.0 17.0 0.0 0.0 5.0 0.0 0.0 5.0 0.0 0.0 39.0 0.0 10.0 76.0 0.0 11.0 36.0

V4 8.0 8.0 7.0 2.0 8.0 8.0 4.0 8.0 8.0 4.0 8.0 8.0 6.0 8.0 8.0 6.0 8.0 7.0 3.0 8.0 7.0 2.0 8.0 8.0 4.0V5 8.3 8.3 8.6 10.0 6.6 6.9 8.0 6.4 6.9 7.8 1.7 1.8 2.8 1.7 1.8 2.8 6.8 6.9 8.4 8.3 8.3 9.6 6.9 6.8 7.8V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 5.4 (cont.)

No Action Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 Alt 8

Var. TY0 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50

G1 and G5 Area – Brackish Marsh - 24,863 acres

V1 82.1 81.8 79.1 68.1 80.7 78.1 67.1 80.7 78.1 67.1 80.7 78.1 67.1 80.7 78.1 67.1 81.8 79.1 68.1 81.8 79.1 68.1 80.7 78.1 67.1V2 12.0 12.0 12.0 8.0 12.0 11.0 8.0 12.0 11.0 8.0 12.0 11.0 8.0 12.0 11.0 8.0 12.0 12.0 8.0 12.0 12.0 8.0 12.0 11.0 8.0

V3-1 74.0 74.0 70.0 25.0 74.0 70.0 25.0 74.0 70.0 25.0 74.0 70.0 25.0 74.0 70.0 25.0 74.0 70.0 25.0 74.0 70.0 25.0 74.0 70.0 25.0V3-2 18.0 17.0 17.0 45.0 15.0 15.0 44.0 15.0 15.0 44.0 15.0 15.0 44.0 15.0 15.0 44.0 17.0 17.0 45.0 17.0 17.0 45.0 15.0 15.0 44.0V3-3 0.0 0.0 0.0 17.0 0.0 0.0 16.0 0.0 0.0 16.0 0.0 0.0 16.0 0.0 0.0 16.0 0.0 0.0 17.0 0.0 0.0 17.0 0.0 0.0 16.0V3-4 8.0 9.0 13.0 13.0 11.0 15.0 15.0 11.0 15.0 15.0 11.0 15.0 15.0 11.0 15.0 15.0 9.0 13.0 13.0 9.0 13.0 13.0 11.0 15.0 15.0V3-5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

V4 12.0 12.0 12.0 8.0 11.0 11.0 7.0 12.0 11.0 7.0 15.0 15.0 10.0 15.0 15.0 10.0 12.0 12.0 8.0 12.0 12.0 8.0 11.0 11.0 7.0V5 4.5 4.5 4.5 4.8 4.8 4.8 5.2 4.4 4.8 5.1 2.3 2.5 3.1 2.1 2.4 3.1 4.5 4.5 4.8 4.5 4.5 4.8 4.8 4.8 5.2V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

F2 Area – Saline Marsh - 6,171 acres

V1 23.1 22.0 11.6 0.0 21.7 9.3 0.0 21.7 9.3 0.0 21.8 9.5 0.0 21.8 9.5 0.0 22.0 12.0 0.0 22.0 11.6 0.0 21.7 9.3 0.0V2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-3 10.0 10.0 0.0 0.0 10.0 0.0 0.0 10.0 0.0 0.0 10.0 0.0 0.0 10.0 0.0 0.0 10.0 0.0 0.0 10.0 0.0 0.0 10.0 0.0 0.0V3-4 61.0 53.0 10.0 0.0 51.0 0.0 0.0 51.0 0.0 0.0 52.0 0.0 0.0 52.0 0.0 0.0 54.0 14.0 0.0 54.0 12.0 0.0 51.0 0.0 0.0V3-5 29.0 37.0 90.0 100 39.0 100 100 39.0 100 100 38.0 100 100 38.0 100 100 36.0 86.0 100 36.0 88.0 100 39.0 100 100

V4 5.0 5.0 3.0 0.0 5.0 3.0 0.0 5.0 3.0 0.0 5.0 3.0 0.0 5.0 3.0 0.0 5.0 3.0 0.0 5.0 3.0 0.0 5.0 3.0 0.0V5 16.0 16.0 16.1 16.5 16.9 16.9 17.1 15.5 16.9 17.0 14.8 15.2 16.2 14.8 15.3 16.2 14.1 14.3 15.9 16.0 15.9 16.3 16.9 16.9 17.0V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

E2, E3, E4 Area – Saline Marsh - 48,050 acres

V1 14.8 13.7 3.5 0.0 13.7 3.5 0.0 13.7 3.5 0.0 13.7 3.5 0.0 13.7 3.5 0.0 13.7 3.5 0.0 13.7 3.5 0.0 13.7 3.5 0.0V2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-4 32.0 25.0 0.0 0.0 25.0 0.0 0.0 25.0 0.0 0.0 25.0 0.0 0.0 25.0 0.0 0.0 25.0 0.0 0.0 25.0 0.0 0.0 25.0 0.0 0.0V3-5 68.0 75.0 100 100 75.0 100 100 75.0 100 100 75.0 100 100 75.0 100 100 75.0 100 100 75.0 100 100 75.0 100 100

V4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V5 14.8 14.8 15.1 15.1 15.0 15.2 15.2 13.9 15.1 15.1 14.9 15.3 15.3 14.4 15.3 15.3 13.6 14.8 14.8 14.8 14.9 14.9 15.1 15.2 15.2V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 5.4 (cont.)

No Action Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 Alt 8

Var. TY0 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50

C9 Area – Brackish Marsh - 1,702 acres

V1 44.7 44.0 37.5 8.6 56.2 54.8 51.8 56.3 54.9 52.2 56.2 54.4 49.7 56.2 54.5 50.1 44.0 37.5 8.6 44.0 37.5 8.6 56.2 53.9 40.2V2 15.0 15.0 13.0 5.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 15.0 13.0 5.0 15.0 13.0 5.0 25.0 25.0 25.0

V3-1 10.0 10.0 5.0 0.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 5.0 0.0 10.0 5.0 0.0 10.0 7.0 0.0V3-2 26.0 25.0 10.0 0.0 35.0 33.0 30.0 35.0 33.0 30.0 35.0 33.0 26.0 35.0 33.0 26.0 25.0 10.0 0.0 25.0 10.0 0.0 35.0 33.0 20.0V3-3 0.0 0.0 23.0 0.0 29.0 27.0 21.0 29.0 27.0 22.0 29.0 26.0 20.0 29.0 26.0 22.0 0.0 23.0 0.0 0.0 23.0 0.0 29.0 31.0 30.0V3-4 64.0 65.0 52.0 0.0 26.0 30.0 39.0 26.0 30.0 38.0 26.0 31.0 44.0 26.0 31.0 42.0 65.0 52.0 0.0 65.0 52.0 0.0 26.0 29.0 35.0V3-5 0.0 0.0 10.0 100 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 100 0.0 10.0 100 0.0 0.0 15.0

V4 10.0 10.0 8.0 2.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 8.0 2.0 10.0 8.0 2.0 10.0 10.0 10.0V5 7.7 7.7 7.7 8.1 3.5 3.1 3.7 3.5 3.1 3.7 5.4 5.3 5.1 4.8 5.2 5.0 7.7 7.7 8.1 7.7 7.7 8.1 4.0 3.5 3.9V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

C2, C3, C4, C5, C6, and C7 Area – Brackish Marsh - 23,381 acres

V1 55.6 54.6 45.1 12.5 54.4 45.7 16.2 54.4 45.8 16.3 54.4 45.7 15.9 54.4 45.7 15.9 54.6 45.1 12.5 54.6 45.1 12.5 54.4 45.7 16.1V2 15.0 15.0 13.0 3.0 25.0 20.0 9.0 25.0 20.0 9.0 25.0 20.0 9.0 25.0 20.0 9.0 15.0 13.0 3.0 15.0 13.0 3.0 25.0 20.0 9.0

V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-2 35.0 34.0 10.0 0.0 35.0 10.0 0.0 35.0 10.0 0.0 35.0 10.0 0.0 35.0 10.0 0.0 34.0 10.0 0.0 34.0 10.0 0.0 35.0 10.0 0.0V3-3 52.0 50.0 60.0 0.0 48.0 63.0 0.0 48.0 63.0 0.0 48.0 62.0 0.0 48.0 62.0 0.0 50.0 60.0 0.0 50.0 60.0 0.0 48.0 63.0 0.0V3-4 13.0 16.0 30.0 17.0 17.0 27.0 41.0 17.0 27.0 41.0 17.0 28.0 38.0 17.0 28.0 38.0 16.0 30.0 17.0 16.0 30.0 17.0 17.0 27.0 41.0V3-5 0.0 0.0 0.0 83.0 0.0 0.0 59.0 0.0 0.0 59.0 0.0 0.0 62.0 0.0 0.0 62.0 0.0 0.0 83.0 0.0 0.0 83.0 0.0 0.0 59.0

V4 10.0 10.0 9.0 2.0 10.0 9.0 3.0 10.0 9.0 3.0 10.0 9.0 3.0 10.0 9.0 4.0 10.0 9.0 2.0 10.0 9.0 2.0 10.0 9.0 3.5V5 6.8 6.8 6.9 7.2 4.0 4.0 4.4 3.6 3.9 4.4 5.2 5.1 5.3 5.1 5.0 5.2 6.8 6.9 7.2 6.8 6.9 7.2 4.3 4.1 4.5V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.00 1.00 1.00

Bayou Dulac Area – Brackish Marsh - 5,577 acres

V1 42.9 42.5 38.4 20.5 43.2 39.0 15.9 43.2 39.0 16.0 43.2 39.0 15.8 42.5 39.0 15.9 42.7 40.9 46.2 42.5 39.0 44.1 42.5 38.2 13.0V2 5.0 5.0 5.0 2.0 5.0 5.0 2.0 5.0 5.0 2.0 5.0 5.0 2.0 5.0 5.0 4.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 2.0

V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-2 30.0 30.0 20.0 0.0 30.0 20.0 0.0 30.0 20.0 0.0 30.0 20.0 0.0 30.0 30.0 15.0 30.0 25.0 30.0 30.0 20.0 30.0 30.0 20.0 0.0V3-3 11.0 10.0 14.0 0.0 13.0 16.0 0.0 13.0 16.0 0.0 13.0 16.0 0.0 11.0 12.0 13.0 11.0 14.0 25.0 10.0 16.0 16.0 10.0 13.0 0.0V3-4 59.0 60.0 66.0 70.0 57.0 64.0 39.0 57.0 64.0 40.0 57.0 64.0 40.0 59.0 58.0 72.0 59.0 61.0 45.0 60.0 64.0 54.0 60.0 67.0 20.0V3-5 0.0 0.0 0.0 30.0 0.0 0.0 61.0 0.0 0.0 60.0 0.0 0.0 60.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 80.0

V4 10.0 10.0 9.0 4.0 10.0 9.0 4.0 10.0 9.0 4.0 10.0 9.0 4.0 10.0 10.0 8.0 10.0 10.0 10.0 10.0 9.0 10.0 10.0 9.0 10.0V5 9.2 9.2 9.2 9.5 7.4 8.4 8.3 6.9 8.4 8.2 7.8 8.6 8.5 7.8 8.6 8.5 8.4 7.5 8.3 9.2 7.7 7.8 7.7 8.2 8.3V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.00 1.00 1.00

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 5.4 (cont.)

No Action Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 Alt 8

Var. TY0 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50 TY1 TY10 TY50

B6 and B7 Area – Brackish Marsh - 42,049 acres

V1 56.9 56.5 52.4 34.5 56.5 52.3 31.2 56.6 52.5 31.5 56.6 52.4 31.2 56.6 52.5 31.4 56.6 52.4 27.8 56.6 52.4 27.8 56.5 52.6 40.0V2 12.0 12.0 11.0 2.0 11.0 11.0 4.0 12.0 11.0 4.0 12.0 11.0 3.0 11.0 10.0 3.0 12.0 12.0 4.0 12.0 12.0 4.0 12.0 12.0 4.0

V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-2 34.0 33.0 25.0 0.0 33.0 20.0 0.0 33.0 20.0 0.0 33.0 20.0 0.0 33.0 20.0 0.0 33.0 20.0 0.0 33.0 20.0 0.0 33.0 20.0 0.0V3-3 59.0 60.0 60.0 38.0 60.0 70.0 64.0 60.0 70.0 65.0 60.0 70.0 64.0 60.0 70.0 64.0 60.0 70.0 59.0 60.0 70.0 59.0 60.0 70.0 60.0V3-4 7.0 7.0 15.0 62.0 7.0 10.0 36.0 7.0 10.0 35.0 7.0 10.0 36.0 7.0 10.0 36.0 7.0 10.0 41.0 7.0 10.0 41.0 7.0 10.0 40.0V3-5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

V4 10.0 10.0 10.0 2.0 10.0 10.0 5.0 10.0 10.0 5.0 10.0 10.0 5.0 10.0 10.0 5.0 10.0 10.0 4.0 10.0 10.0 4.0 10.0 10.0 4.0V5 10.6 10.6 10.9 11.8 11.0 10.4 11.2 10.6 10.4 11.1 11.7 11.1 11.7 11.5 11.0 11.7 10.2 10.1 11.2 10.6 10.1 11.0 11.0 10.5 11.3V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

C11, C12, C13, and C14 – Saline Marsh - 44,030 acres

V1 45.3 44.8 40.5 21.5 44.8 40.5 6.7 44.8 40.5 6.8 44.8 40.5 6.7 44.8 40.5 6.7 44.8 40.1 5.8 44.8 40.1 5.8 44.8 40.1 6.1V2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0V3-3 81.0 79.0 62.0 0.0 79.0 62.0 0.0 79.0 62.0 0.0 79.0 62.0 0.0 79.0 62.0 0.0 79.0 60.0 0.0 79.0 60.0 0.0 79.0 60.0 0.0V3-4 19.0 21.0 38.0 76.0 21.0 38.0 0.0 21.0 38.0 0.0 21.0 38.0 0.0 21.0 38.0 0.0 21.0 40.0 0.0 21.0 40.0 0.0 21.0 40.0 0.0V3-5 0.0 0.0 0.0 24.0 0.0 0.0 100 0.0 0.0 100 0.0 0.0 100 0.0 0.0 100 0.0 0.0 100 0.0 0.0 100 0.0 0.0 100V4 8.0 8.0 7.0 1.0 8.0 7.0 0.0 8.0 7.0 0.0 8.0 7.0 0.0 8.0 7.0 0.0 8.0 7.0 0.0 8.0 7.0 0.0 8.0 7.0 0.0V5 13.2 13.2 13.3 13.8 13.8 14.3 14.6 13.1 14.2 14.5 14.7 14.9 15.0 14.5 14.9 15.0 12.5 13.3 14.4 13.2 13.3 13.8 13.5 14.1 14.5V6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0* V1 = Percent emergent marsh

V2 = Percent open water covered by aquatic vegetationV3 = Interspersion classV4 = Percent open water less than or equal to 1.5 feet deepV5 = SalinityV6 = Aquatic organism access

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Table 5.5. Average Annual Habitat Units by Area and Habitat Type.

*Net benefits calculated as follows: Fresh/Intermediate Marsh Net Benefits = (2.1 x Emergent Marsh AAHUs + Open Water AAHUs) / 3.1

Brackish Marsh Net Benefits = (2.6 x Emergent Marsh AAHUs + Open Water AAHUs) / 3.6

Saline Marsh Net Benefits = (3.5 x Emergent Marsh AAHUs + Open Water AAHUs) / 4.5

Area Alt 2

AAHUs

Alt 3

AAHUs

Alt 4

AAHUs

Alt 5

AAHUs

Alt 6

AAHUs

Alt 7

AAHUs

Alt 8

AAHUs

Palmetto, Creole Bayous Emergent Marsh 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Open Water 0.00 0.00 0.00 0.00 0.00 0.00 0.00Net Benefits* 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Lake Pagie, A6, A7 Emergent Marsh 2621.40 2666.44 2592.25 3012.26 591.56 589.45 544.55

Open Water 861.28 822.23 887.19 496.18 -508.54 13.76 -483.22Net Benefits* 2132.48 2154.16 2118.62 2313.35 285.97 429.54 259.06

G2, G3, G6 Emergent Marsh 1650.39 1671.36 1416.57 1416.95 711.14 -45.29 1237.62

Open Water -7.27 -15.81 5116.51 5116.27 349.84 -29.62 159.83Net Benefits* 1189.93 1202.70 2444.33 2444.54 610.78 -40.94 938.24

G1, G5 Emergent Marsh -328.98 -328.98 -328.98 -328.98 0.00 0.00 0.00

Open Water 75.88 76.36 97.59 97.59 0.00 0.00 0.00Net Benefits* -216.52 -216.38 -210.49 -210.49 0.00 0.00 0.00

F2 Emergent Marsh -29.05 -29.04 -26.70 -26.70 4.68 0.07 -29.25

Open Water 44.05 44.04 40.23 40.23 -6.22 0.44 44.38Net Benefits* -12.80 -12.80 -11.83 -11.83 2.26 0.16 -12.89

E2, E3, E4 Emergent Marsh -5.36 -5.36 -5.36 -5.36 0.03 0.00 0.00

Open Water 10.20 10.20 10.20 10.20 -0.06 0.00 0.00Net Benefits* -1.90 -1.90 -1.90 -1.90 0.01 0.00 0.00

C9 Emergent Marsh 388.48 392.22 369.79 373.74 0.00 0.00 301.14

Open Water -71.35 -73.21 -62.43 -64.34 0.00 0.00 -29.99Net Benefits* 260.75 262.93 249.73 252.05 0.00 0.00 209.16

C2, C3, C4, C5, C6, C7 Emergent Marsh 276.40 281.09 245.66 248.60 0.00 0.00 278.70

Open Water 689.32 686.47 704.37 709.20 0.00 0.00 691.23Net Benefits* 391.10 393.69 373.08 376.54 0.00 0.00 393.29

Bayou Dulac Emergent Marsh -427.63 -425.50 -410.18 -0.41 144.82 98.28 -486.50

Open Water 150.61 149.65 237.86 45.66 -20.28 -5.07 186.47Net Benefits* -267.01 -265.74 -230.17 12.39 98.96 69.57 -299.56

B6, B7 Emergent Marsh 1158.38 1213.92 950.13 987.29 1017.98 1031.61 975.35

Open Water -52.98 -17.92 -263.00 -356.50 169.99 188.04 88.21Net Benefits* 821.89 871.74 613.15 614.02 782.43 797.29 728.92

C11, C12, C13, C14 Emergent Marsh -1647.43 -1641.64 -1660.26 -1651.20 -1807.41 -1808.12 -1767.96

Open Water 1607.79 1601.48 1620.80 1611.14 1771.68 1772.51 1725.49Net Benefits* -924.04 -920.94 -931.14 -926.24 -1012.06 -1012.42 -991.64

Independent Measure Benefits -153.98 -142.01 -155.80 -143.84 7.42 0.00 -10.39Total AAHUs over No Action 3219.90 3325.45 4257.59 4718.61 775.77 243.20 1214.19

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5.6.2 Alternative 2 (NER Plan and RP)

5.6.2.1 Direct

Direct impacts to vegetation resources would primarily result from those project-related

activities that would directly create, disturb, destroy, or otherwise harm existing

vegetation resources. Implementation of Alternative 2 would result in 148 acres of

swamp, 343 acres of fresh marsh, 248 acres of intermediate marsh, and 182 acres of

brackish marsh being directly converted to open water. Alternative 2 would also result in

23 acres of swamp being converted to upland (levee). These direct impacts would be the

result of dredge features WD2, CD1, CD3, CD6, CD7, ED2, ED3, ED6, and ED7 and

levee features CLV1 and CLV2 (Table 5.2). It should be noted that, for purposes of

impact analysis associated with dredge features for all Alternatives, the assumption was

made that the dredge channel itself and the adjacent disposal site would result in marsh

impacts. In reality, dredged material will be used beneficially to create marsh habitat to

the maximum extent practicable. However, the exact nature of the dredged material and

its utility in marsh creation, the locations of marsh creation sites, and the acreage of

created marsh habitat will not be determined until a later date, during pre-construction

engineering and design. Therefore, the aforementioned assumptions were necessary in

order to complete the impact analysis for project features. In light of this, the estimates

of negative impacts to marsh should be viewed as maximums as they should be offset at

least in part by beneficially using dredged material during construction.

Temporary impacts to vegetation would also occur in temporary work areas needed for

construction of project features (Table 5.2). It is estimated that 585 acres of temporary

work areas would be needed for construction of Alternative 2. Minimal additional

impacts to aquatic vegetation are anticipated from these activities since temporary work

areas would largely be located in upland and open water habitats, but some upland

vegetation would be disturbed. The exact nature, extent, and duration of temporary work

areas and associated impacts would be determined during pre-construction engineering

and design. Impacts would be kept to a minimum by use of proper construction

techniques, temporary vegetative cover during construction, and regrading and permanent

vegetation establishment at the end of construction.

Alternative 2 would also create 257 acres of brackish marsh and 72 acres of saline marsh

as a result of features CM2, CM3, CM4, CT1, CT2, CT3, CT6, CT7, CT8, EM1, and

EM3 (Table 5.2). Direct negative impacts to vegetation would be offset by the indirect

benefits that Alternative 2 provides over much larger areas (see indirect benefits below).

5.6.2.2 Indirect

In response to freshwater inputs and associated increased nutrient inputs, indirect impacts

of Alternative 2 would include long-term reduction in losses of vegetation over much of

the project area. Improved distribution of freshwater and nutrients would enhance

vegetative productivity and optimize conditions for maintenance of all vegetative

habitats. Most of the benefits from implementation of Alternative 2 would be seen in the

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Lake Pagie area, south of Falgout Canal, in the Lake Boudreaux area and in the Grand

Bayou area (see Figure 5.2 and Tables 5.4 and 5.5). The majority of the benefits realized

from increased freshwater flows in these areas are seen in increases in both emergent

marsh and submerged aquatic vegetation (Variables 1 and 2 in Table 5.4) and

improvements in marsh edge habitat (Variable 3 in Table 5.4) as compared to No Action.

Some areas are projected to decline at a faster rate with implementation of Alternative 2

due to a reduction in freshwater. The area below the HNC lock complex and the

southwest area of Lake Boudreaux are the main areas expected to be negatively impacted

by reduction in freshwater flows (see Figure 5.2). The majority of the impacts in these

areas are seen in decreases in emergent marsh habitat (Variable 1 in Table 5.4) and

declines in marsh edge habitat (Variable 3 in Table 5.4).

Overall, Alternative 2 would reduce land loss in the project area from 101,570 acres to

91,915 acres, thus preventing the loss of 9,655 acres of marsh habitat over the 50-year

period of analysis. Alternative 2 would yield 3,220 AAHUs over the No Action

Alternative (Figure 5.2 and Table 5.5). See Appendix M (WVA Appendix) for

information on calculation of AAHUs.

5.6.2.3 Cumulative

Over the 50-year period of analysis, a decrease in total wetland vegetative habitats would

occur. However the overall rate of loss compared to Future Without-Project conditions

would be reduced. Over the period of analysis, Alternative 2 would result in the

generation of 3,220 AAHU’s as compared to No Action. When combined with

CWPPRA and other Federal, state, local, and private restoration efforts (Table 5.6),

Alternative 2 would have an even greater impact on vegetation resources, as those

programs would work synergistically to improve habitat conditions across the project

area and the coast.

5.6.3 Alternative 3

5.6.3.1 Direct

Direct impacts of Alternative 3 on vegetation resources would be similar to Alternative 2.

5.6.3.2 Indirect

Indirect impacts of Alternative 3 on vegetation resources would be similar to Alternative

2, but to a greater degree. Alternative 3 would reduce land loss in the project area from

101,570 acres to 91,262 acres, thus preventing the loss of 10,308 acres of marsh habitat

over the 50-year period of analysis. Alternative 3 would yield 3,325 AAHUs (Figure 5.3

and Table 5.5) over the No Action Alternative.

5.6.3.3 Cumulative

Cumulative impacts of Alternative 3 on vegetation resources would be similar to

Alternative 2, but to a greater degree.

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5.6.4 Alternative 4

5.6.4.1 Direct

Direct impacts of Alternative 4 on vegetation resources would be similar to Alternative 2.

5.6.4.2 Indirect

Indirect impacts of Alternative 4 on vegetation resources would be similar to Alternative

2, but to a greater degree. Due to the installation of the pump station at Grand Bayou,

Alternative 4 would have more dramatic impacts on the marshes in the Grand Bayou area

than Alternative 2 (see Figure 5.4 and Tables 5.4 and 5.5). Alternative 4 would reduce

land loss in the project area from 101,570 acres to 89,366 acres, thus preventing the loss

of 12,204 acres of marsh habitat over the 50-year period of analysis. Alternative 4 would

yield 4,258 AAHUs over the No Action Alternative.

5.6.4.3 Cumulative

Cumulative impacts of Alternative 4 on vegetation resources would be similar to

Alternative 2, but to a greater degree.

5.6.5 Alternative 5

5.6.5.1 Direct

Direct impacts of Alternative 5 on vegetation resources would be similar to Alternative 2.

5.6.5.2 Indirect

Indirect impacts of Alternative 5 on vegetation resources would be similar to Alternative

2, but to a greater degree. Due to the installation of the pump station at Grand Bayou,

Alternative 5 would have more dramatic impacts on the marshes in the Grand Bayou area

than Alternative 2 (see Figure 5.5 and Tables 5.4 and 5.5). Alternative 5 would reduce

land loss in the project area from 101,570 acres to 87,636 acres, thus preventing the loss

of 13,934 acres of marsh habitat over the 50-year period of analysis. Alternative 5 would

yield 4,719 AAHUs over the No Action Alternative.

5.6.5.3 Cumulative

Cumulative impacts of Alternative 5 on vegetation resources would be similar to

Alternative 2, but to a greater degree.

5.6.6 Alternative 6

5.6.6.1 Direct

Implementation of Alternative 6 would result in 141 acres of intermediate marsh and 47

acres of brackish marsh being directly converted to open water. These direct impacts

would be the result of dredge feature ED3. 117 acres of temporary impacts to open water

and uplands due to temporary work areas would also occur (Table 5.2).

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5.6.6.2 Indirect

Indirect impacts of Alternative 6 on vegetation resources would be similar to Alternative

2, but to a lesser degree. Alternative 6 would reduce land loss in the project area from

101,570 acres to 101,563 acres, thus preventing the loss of 7 acres of marsh habitat over

the 50-year period of analysis. Alternative 6 would yield 776 AAHUs (Figure 5.6 and

Table 5.5) over the No Action Alternative. The relatively large number of AAHUs in

comparison to the number of acres of emergent marsh loss prevented is due to the fact

that Alternative 6 would generate benefits associated with submerged aquatic vegetation

and marsh edge (WVA variables V2 and V3) despite very little prevention of marsh loss.

5.6.6.3 Cumulative

Cumulative impacts of Alternative 6 on vegetation resources would be similar to

Alternative 2, but to a lesser degree.

5.6.7 Alternative 7

5.6.7.1 Direct

No direct impacts on vegetation resources are anticipated with Alternative 7.

5.6.7.2 Indirect

Indirect impacts of Alternative 7 on vegetation resources would be similar to Alternative

2, but to a lesser degree. Alternative 7 would increase land loss in the project area from

101,570 acres to 104,221 acres, thus resulting in the loss of 2,651 acres of marsh habitat

over the 50-year period of analysis. However, Alternative 7 would yield 243 AAHUs

over the No Action Alternative.

5.6.7.3 Cumulative

Cumulative impacts of Alternative 7 on vegetation resources would be similar to

Alternative 2, but to a lesser degree.

5.6.8 Alternative 8

5.6.8.1 Direct

Implementation of Alternative 8 would result in 50 acres of swamp, 24 acres of fresh

marsh, 125 acres of intermediate marsh, and 121 acres of brackish marsh being directly

converted to open water. Alternative 8 would also result in 23 acres of swamp being

converted to upland (levee). These direct impacts would be the result of dredge features

CD1, CD6, CD7, ED3, and ED6 and levee features CLV1 and CLV2. 41 acres of

temporary impacts to open water and uplands due to temporary work areas would also

occur (Table 5.2).

5.6.8.2 Indirect

Indirect impacts of Alternative 8 on vegetation resources would be similar to Alternative

2, but to a lesser degree. Alternative 8 would reduce land loss in the project area from

101,570 acres to 100,581 acres, thus preventing the loss of 989 acres of marsh habitat

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over the 50-year period of analysis. Alternative 8 would yield 1,214 AAHUs (Figure 5.8

and Table 5.5) over the No Action Alternative.

5.6.8.3 Cumulative

Cumulative impacts of Alternative 8 on vegetation resources would be similar to

Alternative 2, but to a lesser degree.

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Table 5.6. Net Acres Created, Restored, and/or Protected by other Federal, State, Local, and Private

Restoration Efforts (USACE 2004).

Subprovince 1

(acres)

Subprovince 2

(acres)

Subprovince 3

(acres)

Subprovince 4

(acres) Totals

(acres)

Breaux Act

CWPPRA1 33,690 44,913 25,057 30,486 134,146

State 2,543 9,043 5,200 1,972 18,758

PCWRP2 14 41 371 31 457

Mitigation

Civil Works

Projects3

4,990 0 5,000 0 9,990

Mitigation

Regulatory

Permits1

6,411 3,199 2,635 2,983 15,228

Vegetation4 535 878 1,785 1,931 5,129

Section

204/1135,

Beneficial Use

226 414 1,293 3,525 5,458

WRDA5 16,000 33,000 0 0 49,000

Other6 0 2,000 50,000 3,226 426,132

TOTALS 64,410 93,490 91,344 44,158 664,298

Source: The state, parish, FEMA, vegetation, WRDA, Sections 1135/204, and beneficial use

are from Belhadjali, Robertson, and Balkum (2002), Coastal Restoration Division Annual

Project Reviews: December 2002. CWPPRA (Breaux Act) acres are from the District's

November 2003 Task Force book and have been furnished by USFWS. Permit mitigation is

from the District's Regulatory Branch database. Civil works mitigation is from the District's

files. Other is 50,000 acres (20,250 ha) of non-mitigation land bought in fee in the Atchafalaya

Basin by the District.

1 - CWPPRA acreages are based upon 20-year project life; all other acreages are 50 years.

2 - PCWRP = Parish Coastal Wetlands Restoration Program (“Christmas Tree Program”).

3 - In the best-case scenario, compensatory mitigation (for civil works projects and regulatory

permits) results in no net loss of wetlands. Hence, it is not the intent to imply that

compensatory mitigation acreages would contribute to a net increase in wetlands as a result of

the Clean Water Act Section 404 program. Rather, these figures represent an accounting of the

various cumulative impacts to coastal wetlands from Federal, state, local, and private

restoration efforts.

4 - Vegetation = LDNR/NRCS/Soil and Water Conservation Committee Vegetation Planting

Program.

5 - WRDA = Completed Federal Water Resources Development Act projects, including the

Davis Pond and Caernarvon diversions.

6 - Includes 30,558 acres (12,376 ha) restored and 340,348 (137,840 ha) acres enhanced by

North American Wetlands Conservation Act (NAWCA), administered by the USFWS; unable

to determine exact locations.

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5.6.9 Invasive Species - Vegetation

Many factors combine to influence the probability of successful establishment of invasive

species. Each invasive species is uniquely regulated by a particular combination of

environmental factors and an individual propensity to infiltrate an area. Also, natural

vegetative communities vary in their inherent susceptibility to being invaded, which is

additionally influenced by the particular level of stress impinging on an area.

5.6.9.1 No Action Alternative (Future without Project Conditions)

Under the No Action Alternative, existing conditions would likely persist. Invasive

species would likely continue to pose a threat to the floristic integrity of the project area

as landscape disturbance and deterioration is prolonged, stressing the balance that

evolved between Louisiana’s native vegetative communities and their habitat. Degrading

native vegetative communities will become increasingly vulnerable to infestation and,

eventually, be replaced by invasive species that out-compete native species and

aggressively develop dense monocultural stands. Some benefit may be realized from

establishment of invasive species. For example, the robust above and belowground

production of Cogon grass may provide substrate stabilization and biomass contributions,

or water hyacinth may provide potential water quality improvement through nutrient

uptake and retention. However, the potential benefits are not expected to outweigh the

overall impacts anticipated from the proliferation of invasive species. Expected major

impacts caused by spread of invasive species are reduced vegetative biodiversity,

alteration of abiotic factors and coastal ecosystem processes, and reduction of wildlife

food and habitat. Existing invasive species found in the project area would likely

continue to be found (see Table 4.4) and new invasive species may become established.

Likewise, Federal, state, and local laws, programs, and regulations aimed at invasive

species control would continue.

5.6.9.2 Alternative 2 (NER Plan and RP)

5.6.9.2.1 Direct

There may be some minor direct impacts to invasive vegetation due to construction

activities in areas where invasive species exist at the time of construction. Any features

requiring construction activity in vegetated areas may directly impact invasive species,

either temporarily by disturbance during construction or long-term by physically

replacing invasive species habitat with project features. Replanting of disturbed areas

would be accomplished utilizing native plant species.

5.6.9.2.2 Indirect

In general, increased delivery and improved distribution of freshwater and nutrients is

anticipated to nourish, enhance production of, and support diversity of natural vegetative

communities as well as reduce their vulnerability to invasive species threats. Conversely,

system freshening and newly created habitat may provide additional habitat where

conditions are favorable for encroachment by invasive species; however, newly created

areas can also provide opportunity to establish more diverse communities composed of

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native species. Deepening and/or widening of conveyance channels could also increase

the potential for movement of invasive species into previously inaccessible areas.

5.6.9.2.3 Cumulative

Primary cumulative impacts would be the potential improvement in natural vegetative

communities due to nourishment and enhanced production and the resultant reduction in

vulnerability to invasive species threats. Other cumulative impacts include the

cumulative effects of similar Federal, state, local, and private wetland restoration efforts

that would also contribute to reduction in vulnerability to invasive species threats. From

the cumulative impacts perspective, this potential reduction in vulnerability to invasive

species by restoration efforts would be in contrast to continued increases in vulnerability

to invasive species threats due to habitat degradation and invasion by new species.

5.6.9.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree.

5.6.9.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree.

5.6.9.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater degree.

5.6.9.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser degree.

5.6.9.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

Alternative 2, but to a lesser degree.

5.6.9.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree.

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5.7 Wildlife and Habitat

5.7.1 No Action Alternative (Future without Project Conditions)

EO 13186, signed by the President on January 10, 2001, specifies that all Federal

agencies must include protection of migratory bird habitat in their planning efforts.

Louisiana coastal wetlands provide essential stopover habitat for neotropical migratory

birds on their annual migration route. Without places along the way that provide an

adequate food supply for the quick replenishment of fat reserves, shelter from predators,

and water for rehydration, migratory birds may be negatively affected. Louisiana coastal

wetlands provide critical stopover habitat during both fall and spring migration by

providing essential resting and foraging habitat for transgulf neotropical migrant birds.

As Louisiana continues to lose more coastal wetlands, survival of individual migrating

birds may be affected, which may affect population size, and, over the long term, survival

potential for the species as a whole.

The fate of other species groups in coastal Louisiana will be influenced by habitat

conditions. These groups include migratory birds, such as wintering waterfowl, which

rely on the abundant food supply in coastal wetlands to store energy reserves for

migration and nesting (LCWCRTF and WCRA 1998). The Louisiana coastal zone

provides wintering habitat for approximately 3.5 million ducks and geese and nesting

habitat for the resident mottled duck (Michot 1996). The importance of coastal Louisiana

as wintering habitat for millions of ducks and geese cannot be overemphasized. Winter

habitat conditions in the Lower Mississippi Valley and in California’s Central Valley

have been shown to affect survival (Reinecke et al. 1987) and recruitment (Heitmeyer

and Fredrickson 1981; Raveling and Heitmeyer 1989) of some waterfowl species. It is

likely that conditions in Louisiana’s coastal zone may have the same impact on wintering

waterfowl, especially in light of the fact that the area supports 19% of the U.S. winter

population of 14 species of ducks and geese which are counted during winter surveys

(Michot 1996). As habitat conditions along the coast continue to deteriorate, continental

populations of waterfowl, and other migratory bird species utilizing the coastal zone, may

be negatively impacted.

Continuing losses of wintering habitat (Tiner 1984; Forsythe 1985) and a better

appreciation of the interdependence of waterfowl requirements throughout the annual

cycle (Anderson and Batt 1983) have led to a more balanced concern for the conservation

of breeding, migration, and wintering habitats. The North American Waterfowl

Management Plan (NAWMP) (Canadian Wildlife Service [CWS] and USFWS 1986), a

multination agreement for the management of waterfowl, proposes to restore prairie

nesting areas and protect migration and wintering habitat for waterfowl and other

migratory bird populations in the lower Mississippi River and Gulf Coast regions, among

others. The NAWMP identifies coastal Louisiana as part of one of the most important

regions in North America for the maintenance of continental waterfowl populations.

Forested wetlands of the Terrebonne Basin are expected to change to a more frequently

flooded, less diverse community as a result of subsidence and increasing water levels.

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This habitat change is expected to cause a decrease in several bird species which utilize

those habitats. However, bald eagle numbers are expected to increase as their preferred

nesting habitat, cypress swamp, increases. Game mammals such as white-tailed deer,

squirrels, and rabbits are expected to decline. American alligator populations within the

forested wetlands of the Terrebonne Basin are expected to increase with an increase in

open water, swamp, and non-forested wetland habitats.

The greatest threat to fish and wildlife resources across the area is the ongoing loss of

coastal wetlands in the Terrebonne Basin. In the eastern Terrebonne Basin, most wildlife

populations are expected to decline due to high land loss. In the central Terrebonne

Basin, waterfowl, seabirds, shorebirds, raptors, and marsh and woodland resident and

migrant species are all expected to decline. Brown pelican populations are expected to

increase, as are the bald eagle populations in the Penchant marshes where nesting activity

is high in swamp habitat adjacent to fresh marsh. American alligator populations will

likely decline in the Mechant/DeCade area, but are projected to increase in the Penchant

marshes due to an increase in Atchafalaya River influence. In the extreme western

portion of the Terrebonne Basin, most wildlife populations are expected to remain steady.

Marshes adjacent to the Atchafalaya River will continue to receive abundant fresh water,

nutrients, and sediments; hence, they will likely remain healthy and provide quality

habitat for wildlife.

As the Atchafalaya Delta continues to grow, habitat value for wildlife will increase;

especially for waterfowl. The brown pelican is also projected to increase, but primarily

as the result of nesting success projected in other areas of the coast. American alligator

populations are expected to continue increasing across this basin.

See Table 4.5 in Section 4.2.7 for information on the projected status of avifauna,

furbearers, game mammals, and reptiles in the Project Area.

5.7.2 Alternative 2 (NER Plan and RP)

5.7.2.1 Direct

Direct adverse impacts to wildlife resources would primarily result from construction

activities associated with the various features of Alternative 2. Some wildlife species

could be temporarily displaced from an area as disturbance from construction activities

could result in unfavorable conditions for nesting, foraging, and/or other activities.

However, most species would move to an area with more favorable conditions and return

after construction is completed. Permanent displacement may occur with the

construction of permanent project features. Any permanent displacement would be offset

by the benefits associated with restoration.

In order to minimize any potential impacts to nesting bald eagles that may be found in the

project area, project implementation would follow the National Bald Eagle Management

Guidelines. The guidelines recommend:

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• maintaining a specified distance between the activity and the nest (buffer area);

• maintaining natural areas (preferably forested) between the activity and nest trees

(landscape buffers); and

• avoiding certain activities during the breeding season.

On-site personnel would be informed of the possible presence of nesting bald eagles

within the project boundary, and would identify, avoid, and immediately report any such

nests to the proper authorities. If a bald eagle nest is discovered within or adjacent to the

proposed project area, then an evaluation would be performed to determine whether the

project is likely to disturb nesting bald eagles.

In order to minimize any potential impacts to colonial nesting waterbirds that may be

found in the project area, a qualified biologist would inspect the proposed work site for

undocumented nesting colonies during the nesting season prior to construction. To

minimize disturbance to colonial nesting waterbirds, the following restrictions on activity

would be observed:

• for colonies containing nesting brown pelicans, all activity occurring within 2,000

feet of a rookery would be restricted to the non-nesting period (September 15

through March 31)

• for colonies containing nesting wading birds, anhingas, and/or cormorants, all

activity occurring within 1,000 feet of a rookery would be restricted to the nonnesting period (September 16 through April 1)

On-site personnel would be informed of the need to identify colonial nesting waterbirds

and their nests, and would avoid affecting them during the breeding season.

5.7.2.2 Indirect

Indirect impacts to wildlife resources resulting from Alternative 2 would include the

creation, restoration, and protection of wetland habitats utilized by species for nesting,

rearing of young, resting, and foraging activities. Despite some areas of negative impacts

(see Figure 5.2), an overall increase in wetland acreage and quality over much of the

study area (compared to the Future Without-Project conditions) would provide nesting,

brood-rearing, and foraging habitat for resident avian species. Migratory avian species

would also benefit from Alternative 2 as important stopover habitat would be protected

for neotropical migrants and wintering habitat would be created/protected for waterfowl.

Game mammals and furbearers would also benefit from the protection of wetland types

favored by the majority of those species. Reptiles and amphibians, which prefer fresher

wetland types, would also benefit from the reduction in loss of wetland acres. The

invasive nutria would also likely benefit. WVA analysis of Alternative 2 projected a net

benefit of 3,220 AAHUs over the No Action Alternative.

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5.7.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, the net benefit of 3,220 AAHUs associated with Alternative 2 would have an

even greater impact on wildlife resources, as those programs would work synergistically

to improve habitat conditions for wildlife populations across the coast. Continental

populations of migratory avian species, such as neotropical songbirds and waterfowl,

could improve as critical migratory habitat is restored, protected, and enhanced.

Although unlikely to impact their populations on a continental scale, game animals,

furbearers, reptiles, amphibians, and invasive species (especially the nutria) would also

benefit from the cumulative effects of Alternative 2 and other restoration programs.

5.7.3 Alternative 3

5.7.3.1 Direct

Direct impacts of Alternative 3 would generally be similar to Alternative 2.

5.7.3.2 Indirect

Indirect impacts of Alternative 3 would generally be similar to Alternative 2, but to a

greater degree. Alternative 3 would result in the generation of 3,325 AAHUs.

5.7.3.3 Cumulative

Cumulative impacts of Alternative 3 would generally be similar to Alternative 2, but to a

greater degree.

5.7.4 Alternative 4

5.7.4.1 Direct

Direct impacts of Alternative 4 would generally be similar to Alternative 2.

5.7.4.2 Indirect

Indirect impacts of Alternative 4 would generally be similar to Alternative 2, but to a

greater degree. Alternative 4 would result in the generation of 4,258 AAHUs.

5.7.4.3 Cumulative

Cumulative impacts of Alternative 4 would generally be similar to Alternative 2, but to a

greater degree.

5.7.5 Alternative 5

5.7.5.1 Direct

Direct impacts of Alternative 5 would generally be similar to Alternative 2.

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5.7.5.2 Indirect

Indirect impacts of Alternative 5 would generally be similar to Alternative 2, but to a

greater degree. Alternative 5 would result in the generation of 4,719 AAHUs.

5.7.5.3 Cumulative

Cumulative impacts of Alternative 5 would generally be similar to Alternative 2, but to a

greater degree.

5.7.6 Alternative 6

5.7.6.1 Direct

Direct impacts of Alternative 6 would generally be similar to Alternative 2, but to a lesser

degree. Far fewer features would be constructed under Alternative 6 resulting in fewer

direct impacts to wildlife.

5.7.6.2 Indirect

Indirect impacts of Alternative 6 would generally be similar to Alternative 2, but to a

lesser degree. Alternative 6 would result in the generation of 776 AAHUs.

5.7.6.3 Cumulative

Cumulative impacts of Alternative 6 would generally be similar to Alternative 2, but to a

lesser degree.

5.7.7 Alternative 7

5.7.7.1 Direct

Direct impacts of Alternative 7 would be limited to impacts from modified operation of

the Houma Navigation Canal lock complex. No direct construction impacts would occur

due to the fact that Alternative 7 only modifies the operation of the lock complex and

does not address its construction. Direct impacts to wildlife species would be localized,

temporary, and minor in nature.

5.7.7.2 Indirect

Indirect impacts of Alternative 7 would generally be similar to Alternative 2, but to a

lesser degree. Alternative 7 would result in the generation of 243 AAHUs.

5.7.7.3 Cumulative

Cumulative impacts of Alternative 7 would generally be similar to Alternative 2, but to a

lesser degree.

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5.7.8 Alternative 8

5.7.8.1 Direct

Direct impacts of Alternative 8 would generally be similar to Alternative 2, but to a lesser

degree. Fewer features would be constructed under Alternative 8 resulting in fewer direct

impacts to wildlife.

5.7.8.2 Indirect

Indirect impacts of Alternative 8 would generally be similar to Alternative 2, but to a

lesser degree. Alternative 8 would result in the generation of 1,214 AAHUs.

5.7.8.3 Cumulative

Cumulative impacts of Alternative 8 would generally be similar to Alternative 2, but to a

lesser degree.

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5.8 Aquatic Resources

5.8.1 Plankton Resources

5.8.1.1 No Action Alternative (Future without Project Conditions)

The No Action Alternative would result in the persistence of existing conditions

including the continued degradation and eventual loss of wetlands. This loss of wetlands

would eventually result in a decrease of available nutrients and detritus, which could lead

to the conversion of primarily estuarine-dependent plankton species assemblages to more

marine and open water plankton species assemblages.

5.8.1.2 Alternative 2 (NER Plan and RP)

5.8.1.2.1 Direct

Increases in freshwater flows and associated nutrients from proposed features would be

expected to change plankton abundance and species composition. Changes in plankton

species assemblages would likely be similar to what is observed along present day

estuarine salinity gradients except that increased freshwater flows would shift the

plankton community, displacing marine species in favor of fresher and more estuarine,

euryhaline species. During actual construction activities of project features there would

only be short-term minor adverse impacts to plankton populations due to increases in

turbidity, low dissolved oxygen, and introduction of dredged sediments into shallow open

water areas. There would be long-term loss of shallow water habitats due to dredge

disposal activities. However, there is an abundance of shallow open water habitat

available for use by plankton.

5.8.1.2.2 Indirect

Indirect impacts to plankton resources would primarily be related to increases in the

export of dissolved organic compounds and detritus from enhanced marsh habitats that

would benefit local plankton populations by increasing the planktonic food web. It is

unknown whether proposed diversion flows and associated nutrients would result in

noxious blooms of blue-green algae, but there is likely some upper limit to the

assimilation of nutrients into estuarine waters, beyond which blooms would occur.

5.8.1.2.3 Cumulative

Cumulative impacts to plankton resources would primarily be related to the incremental

impact of all past, present, and future actions affecting plankton resources. Alternative 2

would have positive synergistic effects on plankton resources when combined with other

Federal, state, local, and private restoration efforts. Marsh restoration efforts would

result in greater resources for phytoplankton and zooplankton due to export of dissolved

organic compounds and detritus. Alternative 2 and other Federal, state, local, and private

restoration efforts could have negative synergistic effects on plankton resources by

potentially increasing noxious algal blooms associated with diversion flows and

associated nutrients.

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5.8.1.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree.

5.8.1.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree.

5.8.1.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater degree.

5.8.1.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser degree.

5.8.1.7 Alternative 7

Direct and indirect impacts of Alternative 7 would generally be similar to Alternative 2,

but would affect a much smaller area. No direct construction impacts would occur due to

the fact that Alternative 7 only modifies the operation of the lock complex and does not

address its construction. Cumulative impacts would be similar to Alternative 2, but to a

lesser degree.

5.8.1.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree.

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5.8.2 Benthic Resources

5.8.2.1 No Action Alternative (Future without Project Conditions)

The species richness (variety of organisms) of the benthic community typically declines

as one progress from ocean waters upstream into lower salinities, and often reaches a

minimum between 4 and 6 ppt (Day et al. 1989). Hence, it is expected that increases in

benthic community species diversity would occur in the project area as land loss

continues.

5.8.2.2 Alternative 2 (NER Plan and RP)

5.8.2.2.1 Direct

Construction of proposed features and dredging activities would harm existing benthic

communities at the proposed construction sites. In addition, introduction of additional

fresh water into estuarine systems could have short-term impacts on benthic populations

in receiving waters. Introduction of freshwater flows from proposed features would be

expected to change benthic abundance, species composition, and species distribution.

Changes in benthic species assemblages would likely be similar to what is observed

along present day estuarine salinity gradients except that increased freshwater flows

would shift the benthic community, displacing marine species in favor of fresher and

more estuarine, euryhaline species.

5.8.2.2.2 Indirect

Species richness of benthic communities is usually greater in higher salinity waters (Day

et al. 1989). Decreases in salinity would likely reduce benthic species richness as greater

volumes of freshwater are pushed deeper into estuarine basins.

5.8.2.2.3 Cumulative

Cumulative impacts to benthic resources would primarily be related to the incremental

impact of all past, present, and future actions affecting plankton resources. Alternative 2

would have synergistic effects on plankton resources when combined with other Federal,

state, local, and private restoration efforts. Cumulative impacts would be the shifting of

benthic abundance, species composition, and species distribution toward those adapted to

fresher habitats.

5.8.2.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree.

5.8.2.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree.

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5.8.2.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater degree.

5.8.2.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser degree.

5.8.2.7 Alternative 7

Direct and indirect impacts of Alternative 7 would generally be similar to Alternative 2,

but would affect a much smaller area. No direct construction impacts would occur due to

the fact that Alternative 7 only modifies the operation of the lock complex and does not

address its construction. Cumulative impacts would be similar to Alternative 2, but to a

lesser degree.

5.8.2.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree.

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5.9 Fisheries

5.9.1 No Action Alternative (Future without Project Conditions)

The project area supports one of the most productive fisheries in the Nation. However, it

is believed that with no action, sharp declines in fisheries productivity are likely (Minello

et al. 1994; Rozas and Reed et al.1993). Direct impacts to fisheries may result from

events such as hypoxia, but are expected to be smaller in comparison to indirect impacts.

Indirect impacts to fisheries may result from the expected continuation of land loss and

further loss of habitat supportive of estuarine and marine fishery species. In the shortterm, land loss and predicted sea level changes are likely to increase open water habitats

available to marine species, except in the active delta of the Atchafalaya River. In the

long-term, as open water replaces wetland habitat and the extent of marsh to water

interface begins to decrease, fishery productivity is likely to decline (Minello et al. 1994;

Rozas and Reed 1993). This may already be happening in the Barataria and Terrebonne

estuaries. Browder et al. (1989) predicted that brown shrimp catches in Barataria,

Timbalier, and Terrebonne Basins would peak around the year 2000 and may fall to zero

within 52 to 105 years.

Other considerations on the impact to fisheries are predator/prey relationships; water

quality, salinity, and temperature; harvest rates; wetland development activities

(dredge/fill); habitat conversion (e.g., wetland to upland); and access blockages. Habitat

suitability, diversity, population size, and harvest rates influence the future condition of

fisheries. Habitat suitability for fisheries varies by species, and depends on different

water quality and substrate types.

Along with indirect effects of no action on fisheries, restoration efforts in the state (e.g.,

CWPPRA) have aided fisheries habitat, and are likely to continue. Economic interest in

fisheries and interest in Louisiana as a fishery resource for the Nation has increased

significantly. The increase is expected to continue, leading to changes in fishing

technology, fishing pressure, and fishing regulations in order to maintain sustainable

commercial fisheries. It is likely that construction of levees, water control structures, and

hurricane protection features will continue and/or increase as coastal residents protect

themselves and their property from hurricane damage and flooding. All of these

structures alter water flow, potentially block fisheries access, and may directly convert

habitat supportive of fishery species to unsupportive areas.

Although fisheries productivity has remained high (e.g., Caffey & Schexnayder 2002), as

Louisiana has experienced tremendous marsh loss, this level of productivity may be

unsustainable. As marsh loss occurs, a maximum marsh to water interface (i.e., edge) is

reached (Browder et al. 1985). A decline in this interface will follow if marsh loss

continues and the overall value of the area as fisheries habitat will decrease (Minello et

al. 2003). Because fishery productivity has been related to the extent of the marsh to

water interface (Faller 1979; Dow et al. 1985; Zimmerman et al. 1984), it is reasonable to

expect fishery productivity to decline as the amount of this interface decreases.

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As marsh and optimal habitat continue to erode, it is anticipated that oyster resources will

experience a decline in the long-term and a shift in the area of greatest productivity.

Although the conversion of marsh into open water will likely provide temporary new

oyster habitat, the quality of this habitat is expected to decrease as populations become

stressed by increased saltwater intrusion, predation, and lack of adequate shelter resulting

from marsh erosion. Once buffered by interior and barrier wetlands, oyster reefs will be

exposed directly to the gulf as surrounding marshes erode. This is likely to increase

damages to reefs related to storm events. For example, following Hurricane Andrew in

1992, many oyster farmers requested Federal relief for decimated oyster beds.

5.9.2 Alternative 2 (NER Plan and RP)

5.9.2.1 Direct

Direct impacts to fisheries resources from implementation of Alternative 2 would result

from construction of project features. Impacts from construction of water control

structures may include direct mortality due to burial or sudden salinity changes; injury or

mortality due to increased turbidity (e.g. gill abrasion, clogging of feeding apparatus);

modified behavior, and short-term displacement. Dredging and placement of borrow

material associated with dredge features, terracing, and marsh creation would negatively

impact benthic organisms and benthic feeders in dredge channels and disposal areas.

Sessile and slow-moving aquatic invertebrates would be disturbed by the dredge or

excavation activity or buried by the placed material. Construction activities would

temporarily increase turbidity, temperatures, and biological oxygen demand (BOD), and

decrease dissolved oxygen. These temporary conditions would likely displace more

mobile fisheries species from the construction area. Following construction, displaced

fisheries species would likely return to the project area. Smothering of non-mobile

benthic organisms could occur. These impacts would be minimized, as much as

practicable, through implementation of appropriate Best Management Practices.

Direct impacts to fisheries resources would also result from changes in salinity levels in

the project area as a result of water control structures. According to modeled salinity

values, changes in average annual salinities (see Figure 5.10) in the project area, as

compared to the No Action Alternative, generally range from increases of 2.0ppt (area

B5) to decreases of 4.6ppt (Area C9). Areas projected to experience the greatest

decreases in salinity values include the Lake Mechant area, Lake Boudreaux, and the

Grand Bayou area. Areas projected to experience the greatest increases in salinity are

generally in the vicinity of the future location of the Houma Navigation Canal lock

complex. Another way of looking at changes in salinities due to project implementation

is to compare isohaline lines for future without project conditions and future with project

conditions. This can provide a measure of the degree of spatial shift in salinity that can

be expected due to project features. According to modeled salinity values for low

Atchafalaya flows (Figure 5.19), representing dry season salinities, the most notable

change in isohaline lines with project implementation is a shift of the 5 ppt isohaline line

from the north side of Lake Mechant and Lost Lake to the south side. During high

Atchafalaya flows (Figure 5.20), however, the changes in isohaline lines are minor in the

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Lake Mechant/Lost Lake area, but are more noticeable in the Lake Boudreaux and Grand

Bayou areas, as the 5 ppt isohaline line is pushed further into these areas. These changes

in salinities may change the distribution of fish and shellfish species based on their

salinity tolerance. In areas freshened by water control structures and/or dredge channels,

species assemblages would be expected to shift toward the Gulf. Less freshwater tolerant

species, such as brown shrimp and spotted seatrout, may be displaced from freshened

areas. Species such as Gulf menhaden, blue crab, white shrimp, and red drum that

commonly utilize low to medium salinity areas and SAV habitats would likely benefit.

Freshwater fishery species, such as crawfish, catfish, largemouth bass, and other sunfish

should benefit from implementation of Alternative 2. Conversely, in areas that see an

increase in salinities, more saltwater-tolerant species such as brown shrimp and spotted

seatrout would move further into area estuaries. For oysters, changes in salinities outside

of their optimum range (5-15ppt) could increase mortality, affect reproduction, and affect

spat settlement. Likewise, in areas that are currently too fresh or too saline to support

healthy oyster populations, changes in salinity due to project implementation could

provide new areas for oyster production (see Section 5.15.10.2 for further discussion of

oyster impacts).

Organism access to essential fish habitat would be impeded by some structures included

in Alternative 2 and would be enhanced by others. Table 5.7 summarizes fishery access

impacts by feature. Features potentially having a negative impact on large areas include

WW2, CL1, CP1, and EP7. The weir at Grand Pass (WW2) would reduce the size of the

channel between Lake Mechant and Caillou Lake from 900 feet wide by 65 feet deep

down to 100 feet wide by 12 feet deep. The modified operation of the lock complex

(CL1) would block organism movement in the HNC; however, other natural routes of

movement (e.g. Bayou Grand Caillou) would remain open. The plug in Robinson Canal

(CP1) would prevent organism movement between Lake Boudreaux and Bayou Petit

Caillou, limiting access to Lake Boudreaux from the east to Boudreaux Canal. The weir

at Cutoff Canal (EP7) would reduce the size of the canal from 350 feet wide by 12 feet

deep down to 20 feet wide by 5 feet deep.

5.9.2.2 Indirect

Implementation of Alternative 2 is projected to provide a net benefit of 3,220 AAHUs

compared to the No Action Alternative. The vast majority of AAHUs associated with

implementation of Alternative 2 (see Figure 5.2) are located near Lake Decade, below

Falgout Canal, in Lake Boudreaux, and near Grand Bayou. Declines in fishery

productivity are expected to be reduced in these areas through the implementation of

Alternative 2, and the long-term sustainability of a productive fishery would be more

likely than with No Action. Indirect benefits to fisheries should result from increased

productivity, land building, and acreage of marsh and SAV habitats that are supportive of

freshwater, estuarine, and marine fishery species. Subsidence and predicted sea level rise

would be less likely to increase open water habitats. The ARTM project is designed to

slow the loss of marsh habitat in the project area and generally improve conditions for

SAV and other highly productive forms of essential fish habitat. Inflows of fresh water

and nutrients are expected to create and maintain wetlands, which provide food and cover

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to juvenile fish, shrimp, crabs, oysters, and other biota. As a result, the project area

would be expected to better maintain most of its current ability to support Councilmanaged species (such as white shrimp, brown shrimp, and red drum), as well as the

estuarine-dependent species (such as spotted seatrout, gulf menhaden, striped mullet, and

blue crab) that are preyed upon by other Council-managed species (such as mackerels,

red drum, snappers, and groupers) and highly migratory species (such as billfish and

sharks). Potential increases in submerged aquatic vegetation will increase the habitat

required for juveniles to escape predation.

Although implementation of Alternative 2 is projected to result in a net gain in AAHUs

across the project area, some areas are projected to be negatively impacted. The area

below the HNC lock complex and the southwest area of Lake Boudreaux are the main

areas expected to be negatively impacted by reduction in freshwater flows. Declines in

fishery productivity are expected to accelerate in these areas as a result of implementation

of Alternative 2.

5.9.2.3 Cumulative

Restoration efforts in the state (e.g., CWPPRA, the Community-based Restoration

Program sponsored by the NMFS Restoration Center, various state and local efforts, and

others) have aided fisheries habitat and are likely to continue to do so. Economic interest

in fisheries, and interest in Louisiana as a fishery resource for the Nation, has increased

significantly in the recent past. This increase is expected to continue and lead to changes

in fishing technology, fishing pressure, and fishing regulations, in order to maintain

sustainable commercial fisheries. It is likely that the construction of levees, water control

structures and hurricane protection features, which can result in direct loss of habitat,

alter water flow, and have the potential to block fisheries access to habitat, are likely to

continue and/or increase, as coastal residents protect themselves and their property from

hurricane damage and flooding. Implementation of Alternative 2 would contribute to an

overall benefit to fisheries compared to the future with no action.

Table 5.7. Project measures and associated potential fishery access impacts (refer to Figure 5.1

above or Appendix L Annex 4 Engineering Drawings for locations of measures).

Measure ID and

Name

Measure

Description

Existing Fishery

Access

Fishery Access With

Project

Implementation

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Measure ID and

Name

Measure

Description

Existing Fishery

Access

Fishery Access With

Project

Implementation

WO2 – West

Shoreline

Protection #2

48,000 feet of rip-rap

bankline protection

along Bayou Chene

and Avoca Island

Cutoff

Fishery access to

marshes is limited to

major bayous and

canals along Bayou

Chene and Avoca

Island Cutoff

Fishery access to

marshes through

major bayous and

canals would not be

impacted. Fishery

access to existing

shoreline along Bayou

Chene and Avoca

Island Cutoff would be

restricted during

normal water levels.

WP1 – West Plug

#1

Soil plug in access

channel to small

saline marsh area

Provides movement

between Bayou

duLarge and small

saline marsh area.

May provide some

movement between

Bayou duLarge and

Caillou Lake.

Measure would

completely restrict

access from Bayou

duLarge to small saline

marsh area.

WS4 – West

Diversion

Structure #4

Six 15’ x 15’ gated

box culverts in Avoca

Island Levee

No access currently

exists.

Fishery access would

be enhanced by

placement of box

culverts.

WW2 – West Weir

#2

Rock-filled sheet pile

weir with 100’ wide x

12’ deep boat

opening at Grand

Pass

Major route between

Lake Mechant/Bayou

duLarge and Caillou

Lake. Current size is

approximately 900

feet wide by up to 65

feet deep.

Fishery access would

be reduced to an

opening 100 feet wide

by 12 feet deep.

CC1 and CC2 –

Central Culverts

#1 and #2

Each consists of six

10’ x 10’ box culverts

in proposed dredge

channel (CD4) under

Hwy 24

Open channels

(GIWW and Bayou

Terrebonne) currently

exist in vicinity of

proposed structures.

Fishery access would

not be significantly

improved due to

existence of open

channels immediately

adjacent to proposed

structures.

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Measure ID and

Name

Measure

Description

Existing Fishery

Access

Fishery Access With

Project

Implementation

CC3 – Central

Culvert #3

Six 10’ x 10’ gated

water control

structures on Bayou

Provost at Bayou

Grand Caillou

Connection between

Bayou Provost and

Bayou Grand Caillou

currently provides

fishery access.

Connection between

Bayou Provost and

Bayou Grand Caillou

would be similar to

existing opening under

normal operating

conditions (gates

open).

CC4 – Central

Culvert #4

Six 10’ x 10’ gated

water control

structures on Falgout

Canal between HNC

and Bayou Grand

Caillou

No access currently

exists at the proposed

feature location.

Movement between

HNC and Bayou Grand

Caillou through

Falgout Canal would

be enhanced during

normal operating

conditions (gates

open) due to

placement of box

culverts.

CC5-CC12 – Central

Culverts 5 thru 12

Gated culverts to

replace existing

culverts.

Limited fishery access

currently exists.

Fishery access would

be largely blocked due

to flap gates on

structures.

CC13 – Central

Culvert #13

Six 10’ x 10’ gated

box culverts under

Highway 57

No access currently

exists.

Fishery movement

between Bayou Grand

Caillou and Lake

Boudreaux would be

enhanced due to

placement of box

culverts and dredging

(measure CD6).

CC14 – Central

Culvert #14

Three 4’ x 4’ flapgated culverts with

stop log bays

Limited fishery access

currently exists.

Fishery access would

be improved during

periods when

structures are open

(roughly 50% of the

time) and would be

similar to existing at

other times.

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Measure ID and

Name

Measure

Description

Existing Fishery

Access

Fishery Access With

Project

Implementation

CC15 – Central

Culvert #15

Timber weir with

three 8’ boat

openings

Channel currently

open for fishery

access. Existing

channel size is

approximately 70 feet

wide x 3.5 feet deep

Fishery access would

be reduced to an

opening 24 feet wide x

1 foot deep.

CL1 – Central Lock

Complex #1

Multi-purpose

operation of the HNC

lock complex

No lock complex

currently in place.

Assumed construction

completion in 2025

under Morganza to

the Gulf project.

Flood gates assumed

to be closed for two

months per year,

blocking fishery

movement on HNC.

Flood gates assumed

to be closed most of

the year, blocking

fishery movement on

the HNC.

CLV1 – Central

Levee #1

5200-ft. forced

drainage levee

Limited fishery access

through small cut in

existing levee

currently exists,

although fish use is

likely limited due to

habitat conditions.

Fishery access through

levee would be

blocked except during

infrequent openings of

flap gate in pump

station.

CLV2 – Central

Levee #2

1800-ft. forced

drainage levee

Fishery access

currently exists but is

limited to high tide

events.

Fishery access to

would be blocked, but

inaccessible area

would be of limited

extent.

CP1 – Central Plug

#1

Soil plug in Robinson

Canal

Channel currently

open for fishery

access. Existing

channel size is

approximately 150

feet wide by up to 30

feet deep.

Fishery movement

through this channel

would be eliminated.

Fishery access to Lake

Boudreaux from the

east would be limited

to Boudreaux Canal.

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Measure ID and

Name

Measure

Description

Existing Fishery

Access

Fishery Access With

Project

Implementation

CP2 – Central Plug

#2

Soil plug in canal. Fishery access is

currently poor due to

remnant of plug at

feature location.

Existing channel size is

approximately 50 feet

wide by variable

shallow depth.

Measure would

completely restrict

fishery movement in

canal. However,

access would still exist

in adjacent canal (see

CC15 above)

CS1 – Central

Diversion

Structure #1

Six 10’ x 10’ gated

box culverts on

Bayou Butler

Limited fishery access

currently exists.

Fishery access would

be enhanced under

normal operating

conditions (gates

open).

EC2 – East Culvert

#2

Five 5’ x 5’ gated box

culverts in canal

Fishery access

currently exists.

Fishery access would

be similar to existing

under normal

operating conditions

(gates open).

EC3 – East Culvert

#3

Ten 5’ x 5’ gated box

culverts with variable

crest outfall

No fishery access

currently exists.

Fishery access would

be limited under

normal operating

conditions due to

variable crest outfall

and gates. Access

would be enhanced

during periods when

structure is open.

EC5 – East Culvert

#5

470 ft. wide by 14

foot deep gated

water control

structure under Hwy

24 at Grand Bayou

No fishery access

currently exists.

Fishery access would

be enhanced under

normal operating

conditions (gates

open) in conjunction

with dredging (ED5).

EC6 and EC7 – East

Culverts #6 and #7

Each consists of eight

8’ x 8’ gated box

culverts on St. Louis

Canal

Limited fishery access

currently exists.

Fishery access would

be enhanced under

normal operating

conditions (gates

open) in conjunction

with dredging (ED2).

EG1 and EG2 – East

Spoil Gap #1 and

#2

Gaps in canal spoil

banks.

No fishery access

currently exists.

Fishery access would

be enhanced.

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Measure ID and

Name

Measure

Description

Existing Fishery

Access

Fishery Access With

Project

Implementation

EP7 – East Plug #7 Weir with 20’ wide x

5’ deep boat bay on

Cutoff Canal north of

Bayou Point au Chien

Channel currently

open for fishery

access. Existing

channel size is

approximately 350

feet wide x 12 feet

deep.

Fishery access would

be reduced to an

opening 20 feet wide

by 5 feet deep.

EP8 – East Plug #8 Soil plug in Bayou

L’eau Bleu adjacent

to Hwy 24

Channel currently

open for fishery

access. Existing

channel size is

approximately 100

feet wide x 10 feet

deep.

Fishery access through

Bayou L’eau Bleu

would be eliminated.

However, modification

of the proposed

feature to include a

gated structure may

be needed in order to

accommodate local

drainage, thereby

providing some fishery

access.

ES2 – East

Diversion

Structure #2

4000 cfs pump

station

No fishery access

currently exists.

Fishery access would

be blocked during

normal pump

operation. Fishery

access would be

enhanced, in

conjunction with

dredging (ED5), when

pump is not being

operated and gates

are open.

EX1– East Removal

#1

Removal of rock weir

across canal

Fishery access is

currently limited due

to weir across canal.

Fishery access would

be enhanced.

EX2– East Removal

#2

Removal of soil plug

in canal

Fishery access is

currently limited due

to plug.

Fishery access would

be enhanced.

Dredge Channels Dredge channels of

various lengths,

widths, and depths

Variable Fishery access would

improve with all

dredge features.

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Measure ID and

Name

Measure

Description

Existing Fishery

Access

Fishery Access With

Project

Implementation

Marsh Berms Marsh berms of

various lengths

Variable Fishery access would

be blocked in

immediate vicinity of

berms but fishery

access in broader area

is not expected to be

impacted due to other

routes of ingress and

egress.

Marsh Terracing Marsh terraces of

various sizes

Currently open water Fishery access would

not be impacted.

5.9.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would be similar to Alternative

2. Alternative 3 is projected to provide a net benefit of 3,325 AAHUs compared to the

No Action Alternative (see Figure 5.3).

5.9.4 Alternative 4

5.9.4.1 Direct

Direct impacts of Alternative 4 on fisheries resources are expected to be similar to

Alternative 2. However, reductions in salinities in the Grand Bayou basin would be

much more pronounced than with Alternative 2. Average annual salinity values in the

Grand Bayou basin are projected to be between 6.6ppt and 11.6ppt lower than with No

Action over the period of analysis. Lower salinity water is expected to extend much

further into the Grand Bayou basin during the dry and wet seasons as evidenced by

projected changes in isohalines (Figures 5.23 and 5.24). These changes in salinity would

cause much more dramatic shifts in the fish and shellfish communities in the area. In

addition, construction of the plug in Bayou L’eau Blue and the pump station at Grand

Bayou would impede organism movement between the GIWW and Grand Bayou.

5.9.4.2 Indirect

Indirect impacts of Alternative 4 on fisheries resources are expected to be similar to

Alternative 2, but to a greater degree. Alternative 4 is projected to provide 4,258 AAHUs

compared to the No Action Alternative (see Figure 5.4).

5.9.4.3 Cumulative

Cumulative impacts of Alternative 4 on fisheries resources are expected to be similar to

Alternative 2, but to a greater degree.

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5.9.5 Alternative 5

5.9.5.1 Direct

Direct impacts of Alternative 5 on fisheries resources are expected to be similar to

Alternative 2. However, reductions in salinities in the Grand Bayou basin would be

much more pronounced than with Alternative 2. Average annual salinity values in the

Grand Bayou basin are projected to be between 6.6ppt and 11.6ppt lower than with No

Action over the period of analysis. Lower salinity water is expected to extend much

further into the Grand Bayou basin during the dry and wet seasons as evidenced by

projected changes in isohalines (Figures 5.25 and 5.26). These changes in salinity would

cause much more dramatic shifts in the fish and shellfish communities in the area. In

addition, construction of the plug in Bayou L’eau Blue and the pump station at Grand

Bayou would impede organism movement between the GIWW and Grand Bayou.

5.9.5.2 Indirect

Indirect impacts of Alternative 5 on fisheries resources are expected to be similar to

Alternative 2, but to a greater degree. Alternative 5 is projected to provide 4,719 AAHUs

compared to the No Action Alternative (see Figure 5.5).

5.9.5.3 Cumulative

Cumulative impacts of Alternative 5 on fisheries resources are expected to be similar to

Alternative 2, but to a greater degree.

5.9.6 Alternative 6

5.9.6.1 Direct

Direct impacts of Alternative 6 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree. Reductions in salinities in the Lake Mechant area,

Lake Boudreaux, and the Grand Bayou area would be much less pronounced than with

Alternative 2 due to the lack of implementation of flow management measures.

According to modeled salinity values, changes in average annual salinities (see Figure

5.14) in the project area, as compared to the No Action Alternative, generally range from

increases of 0.2ppt (areas H2 and Big Carencro Bayou) to decreases of 2.2ppt (Grand

Bayou Basin). Projected isohaline lines for Alternative 6 are similar to the No Action

Alternative during dry season conditions (Figure 5.27). During wet season conditions,

lower salinity water extends further into the Grand Bayou basin (Figure 5.28).

Organism ingress and egress impacts due to features WP1 and CP1 would be eliminated

under Alternative 6. However, the modified operation of the lock complex (CL1) would

still impact organism movement.

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5.9.6.2 Indirect

Indirect impacts of Alternative 6 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree. Alternative 6 is projected to provide 776 AAHUs

compared to the No Action Alternative (see Figure 5.6).

5.9.6.3 Cumulative

Cumulative impacts of Alternative 6 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree.

5.9.7 Alternative 7

5.9.7.1 Direct

No direct impacts to fisheries resources due to construction activities would result from

implementation of Alternative 7 due to the fact that Alternative 7 only involves the

modified operation of the lock complex and does not involve any construction. Direct

impacts due to changes in salinity levels would still occur, but to a much lesser degree

than with Alternative 2. According to modeled salinity values, changes in average annual

salinities (see Figure 5.15) in the project area, as compared to the No Action Alternative,

generally range from increases of 0.6ppt (areas below the lock complex) to decreases of

2.3ppt (Lake Boudreaux area). Isohaline lines associated with Alternative 7 are very

similar to No Action (Figures 5.29 and 5.30).

Organism ingress and egress impacts due to features WP1 and CP1 would be eliminated

under Alternative 7. However, the modified operation of the lock complex (CL1) would

still impact organism movement.

5.9.7.2 Indirect

Indirect impacts of Alternative 7 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree. Alternative 7 is projected to provide 243 AAHUs

compared to the No Action Alternative (see Figure 5.7).

5.9.7.3 Cumulative

Cumulative impacts of Alternative 7 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree.

5.9.8 Alternative 8

5.9.8.1 Direct

Direct impacts of Alternative 8 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree. Reductions in salinities in the Lake Mechant area

would not occur due to the lack of implementation of dredge feature WD2 in the

Penchant Basin. Salinity changes in the Lake Boudreaux and Grand Bayou areas would

be similar to those associated with Alternative 2. According to modeled salinity values,

changes in average annual salinities (see Figure 5.16) in the project area, as compared to

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the No Action Alternative, generally range from increases of 1.2ppt (area B5) to

decreases of 2.8ppt (Lake Boudreaux area). Projected isohaline lines for Alternative 8

are similar to the No Action Alternative during dry season conditions (Figure 5.31).

During wet season conditions, lower salinity water extends further into Lake Boudreaux

and the Grand Bayou basin (Figure 5.32).

Organism ingress and egress impacts due to feature WP1 would be eliminated under

Alternative 8. However, the modified operation of the lock complex (CL1) and the

Robinson Canal plug (CP1) would still impact organism movement.

5.9.8.2 Indirect

Indirect impacts of Alternative 8 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree. Alternative 8 is projected to provide 1,214 AAHUs

compared to the No Action Alternative (see Figure 5.8).

5.9.8.3 Cumulative

Cumulative impacts of Alternative 8 on fisheries resources are expected to be similar to

Alternative 2, but to a lesser degree.

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5.10 Essential Fish Habitat (EFH)

Per 50 CFR 600.920(e)(3), all EFH assessments must include the following information:

Mandatory Contents of EFH Assessment

• Description of the action

• Analysis of the potential adverse effects of the action on EFH and the managed

species

• Federal agency’s conclusions regarding the effects of the action on EFH

• Proposed mitigation, if applicable

Mandatory contents of the EFH assessment for the ARTM project can be found at the

following locations within this document:

1. Description of the action. A description of each of the proposed Alternatives, a

description of each measure included in each Alternative, and maps with locations

of measures can be found in Section 3.3 of this document. A description of each

of the proposed Alternatives is repeated at the beginning of Chapter 5,

Environmental Consequences.

2. Analysis of the potential adverse effects of the action on EFH and the

managed species. An analysis of the direct, indirect, and cumulative impacts of

the Alternatives on EFH and managed species can be found below in this section.

A description of historic and existing conditions of EFH in the project area can be

found in Section 4.2.10 above. An analysis of the direct, indirect, and cumulative

impacts of the Alternatives on fisheries in general can be found in Section 5.9

above. Wetland impact acreage estimates of each feature can be found in Table

5.2. Fishery access impacts of each feature can be found in Table 5.7.

3. Federal agency’s conclusions regarding the effects of the action on EFH.

Despite some adverse impacts to EFH, the project is expected to result in a

substantial net benefit to EFH when compared to the No Action Alternative.

Specific conclusions regarding the effects on EFH can be found within the

analysis of direct, indirect, and cumulative impacts of each Alternative below.

4. Proposed mitigation, if applicable. Alternatives were developed in accordance

with Corps planning guidance at ER 1105-2-100 which directs that ecosystem

restoration projects be designed to avoid the need for compensatory fish and

wildlife mitigation. Formulation of project alternatives was conducted in

compliance with this guidance. Only Alternative 7 would result in a net loss of

emergent marsh habitat and would, therefore, require mitigation. Alternative 7

was not selected as the National Ecosystem Restoration plan or the

Recommended Plan. Therefore, no discussion of proposed mitigation is

presented. While compensatory mitigation is not warranted with regard to EFH,

other measures in the form of impact avoidance and minimization will be

undertaken during the pre-construction engineering and design phase.

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5.10.1 No Action Alternative (Future without Project Conditions)

Although previous restoration efforts in the LCA Study area have helped maintain some

categories of EFH, the cumulative impacts of land loss, conversion of habitats, sea level

change, increased storm intensity, etc., are expected to lead to a net decrease in the

habitat most supportive of estuarine and marine species. The direct losses of highly

productive forms of EFH would lead to losses of shallow habitat, due to the exposed

nature of the shallow open water bottoms that are being formed. Shallow waters are

likely to become deep waters, and salinity gradients would be less estuarine, with a

sharper distinction between saline and freshwater habitat, as coastal residents further

attempt to protect self and property with levees, flood gates, and other water control

structures.

It is believed that marsh loss that has been experienced to date has increased this

land/water interface and increased fishery production. As land loss continues, it is

believed that this interface would approach a maximum and begin to decline. This

would, in turn, result in a decline in fishery production. In some areas, continued marsh

loss is already resulting in the reduction of this interface.

With no action, the conversion of categories of EFH, such as inner marsh and marsh

edge, to estuarine water column and mud, sand, or shell substrates is expected to

continue. Over time, the no action alternative would result in a substantial decrease in

the quality of EFH in the project area, and reduce the area’s ability to support Federally

managed species. Analysis of rates of wetland loss in the project area indicated that

approximately 21% of the wetlands will be lost by the year 2065.

The Future Without-Project condition would indirectly impact species that are linked in

the food chain to directly affected species. Population reductions in directly affected

species, such as brown shrimp and white shrimp, affect species dependent on shrimp for

food. As marsh, barrier islands, and other EFH are directly lost, less protection would be

available to remaining EFH. These areas would be more susceptible to storm, wind, and

wave erosion. A decrease in species productiveness would result as populations are

stressed by habitat displacement and reduction.

5.10.2 Alternative 2 (NER Plan and RP)

5.10.2.1 Direct

Implementation of Alternative 2 would result in some emergent wetland EFH being

directly converted to open water. These direct impacts would be the result of dredge

features WD2, CD1, CD3, CD6, ED2, ED3, ED6, and ED7. These features would

impact a total of 773 acres of marsh habitat. These features would also impact 614 acres

of open water habitat (Table 5.2). It should be noted that, for purposes of impact analysis

associated with dredge features for all Alternatives, the assumption was made that the

dredge channel itself and the adjacent disposal site would result in marsh impacts. In

reality, dredged material will be used beneficially to create marsh habitat to the maximum

extent practicable. However, the exact nature of the dredged material and its utility in

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marsh creation, the locations of marsh creation sites, and the acreage of created marsh

habitat will not be determined until a later date, during pre-construction engineering and

design. Therefore, the aforementioned assumptions were necessary in order to complete

the impact analysis for project features. In light of this, the estimates of negative impacts

to marsh should be viewed as maximums as they should be offset at least in part by

beneficially using dredged material during construction.

Temporary impacts to EFH would also occur in temporary work areas needed for

construction of project features. It is estimated that 585 acres of upland and open water

habitat for temporary work areas would be needed for construction of Alternative 2. The

exact nature, extent, and duration of temporary work areas and associated impacts would

be determined during pre-construction engineering and design. Impacts would be kept to

a minimum by use of Best Management Practices.

Alternative 2 would also create 329 acres of marsh habitat as a result of features CM2,

CM3, CM4, CT1, CT2, CT3, CT6, CT7, CT8, EM1, and EM3 (Table 5.2). Direct

negative impacts to EFH would be offset by the indirect benefits that Alternative 2

provides to high quality EFH (i.e. emergent wetland and submerged aquatic vegetation)

over much larger areas (see indirect benefits below).

5.10.2.2 Indirect

Alternative 2 would reduce land loss in the project area from 101,570 acres to 91,915

acres, thus preventing the loss of 9,655 acres of emergent marsh habitat over the 50-year

period of analysis when compared to the No Action Alternative. With implementation of

Alternative 2, important categories of EFH such as emergent wetlands would not be

converted to less productive forms of EFH (e.g., estuarine water column, and mud, sand,

or shell substrates) as is expected with no action. Anticipated increases in SAVs would

increase the amount of habitat available for juvenile life stages to escape predation and

therefore increase the quality of habitat. Alternative 2 would benefit categories of EFH

that have been designated for white shrimp, brown shrimp, red drum, and gulf stone crab.

In addition, categories of EFH that are maintained in quality would be supportive of

economically important estuarine-dependent species such as spotted seatrout, sand

seatrout, southern flounder, black drum, gulf menhaden, striped mullet, Atlantic croaker,

and blue crab. Some of these species serve as prey for other species managed under the

Magnuson-Stevens Act (e.g., mackerels, snappers, and groupers) and highly migratory

species managed by NMFS (e.g., billfishes and sharks).

Although implementation of Alternative 2 is projected to result in a reduction in the rate

of loss of emergent marsh habitat across the project area, some areas are projected to be

negatively impacted. The area below the HNC lock complex and the southwest area of

Lake Boudreaux are the main areas expected to be negatively impacted by reduction in

freshwater flows. Emergent wetland EFH in these areas is expected to be converted to

less productive forms at a faster rate than would be expected with no action.

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Organism access to essential fish habitat would be impeded by some structures included

in Alternative 2 and would be enhanced by others. Table 5.7 summarizes fishery access

impacts by feature. Features potentially having a negative impact on large areas include

WW2, CL1, CP1, and EP7. The weir at Grand Pass (WW2) would reduce the size of the

channel between Lake Mechant and Caillou Lake from 900 feet wide by 65 feet deep

down to 100 feet wide by 12 feet deep. The modified operation of the lock complex

(CL1) would block organism movement in the HNC; however, other natural routes of

movement (e.g. Bayou Grand Caillou) would remain open. The plug in Robinson Canal

(CP1) would prevent organism movement between Lake Boudreaux and Bayou Petit

Caillou, limiting access to Lake Boudreaux from the east to Boudreaux Canal. The weir

at Cutoff Canal (EP7) would reduce the size of the canal from 350 feet wide by 12 feet

deep down to 20 feet wide by 5 feet deep.

5.10.2.3 Cumulative

Over the period of analysis, Alternative 2 would reduce land loss in the project area by

9,655 acres. When combined with CWPPRA and other Federal, state, local, and private

restoration efforts, Alternative 2 would have an even greater impact on EFH resources, as

those programs would work synergistically to improve habitat conditions across the

coast.

5.10.3 Alternative 3

5.10.3.1 Direct

Direct impacts of Alternative 3 would be similar to Alternative 2.

5.10.3.2 Indirect

Indirect impacts of Alternative 3 would be similar to Alternative 2, but would provide

greater benefits. Alternative 3 would reduce land loss in the project area from 101,570

acres to 91,262 acres, thus preventing the loss of 10,308 acres of emergent marsh habitat

over the 50-year period of analysis when compared to the No Action Alternative.

5.10.3.3 Cumulative

Cumulative impacts of Alternative 3 would be similar to Alternative 2, but to a greater

degree.

5.10.4 Alternative 4

5.10.4.1 Direct

Direct impacts of Alternative 4 would be similar to Alternative 2.

5.10.4.2 Indirect

Indirect impacts of Alternative 4 would be similar to Alternative 2, but would provide

greater benefits. Alternative 4 would reduce land loss in the project area from 101,570

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acres to 89,366 acres, thus preventing the loss of 12,204 acres of emergent marsh habitat

over the 50-year period of analysis when compared to the No Action Alternative.

Impediments to organism access above and beyond those associated with Alternative 2

would occur due to the plug on Bayou L’Eau Bleu. This would prevent organism

movement between Grand Bayou and the GIWW.

5.10.4.3 Cumulative

Cumulative impacts of Alternative 4 would be similar to Alternative 2, but to a greater

degree.

5.10.5 Alternative 5

5.10.5.1 Direct

Direct impacts of Alternative 5 would be similar to Alternative 2.

5.10.5.2 Indirect

Indirect impacts of Alternative 5 would be similar to Alternative 2, but would provide

greater benefits. Alternative 5 would reduce land loss in the project area from 101,570

acres to 87,636 acres, thus preventing the loss of 13,934 acres of emergent marsh habitat

over the 50-year period of analysis when compared to the No Action Alternative.

Impediments to organism access above and beyond those associated with Alternative 2

would occur due to the plug on Bayou L’Eau Bleu. This would prevent organism

movement between Grand Bayou and the GIWW.

5.10.5.3 Cumulative

Cumulative impacts of Alternative 5 would be similar to Alternative 2, but to a greater

degree.

5.10.6 Alternative 6

5.10.6.1 Direct

Implementation of Alternative 6 would result in some emergent wetland EFH being

directly converted to open water. These direct impacts would be the result of dredge

feature ED3 (Table 5.2). This feature would impact a total of 167 acres of marsh habitat.

This feature would also impact 88 acres of open water habitat. 117 acres of upland and

open water habitat for temporary work areas would be needed for construction of

Alternative 6. Direct negative impacts to EFH would be offset by the indirect benefits

that Alternative 6 provides to high quality EFH (i.e. emergent wetland and submerged

aquatic vegetation) over much larger areas (see indirect benefits below).

5.10.6.2 Indirect

Indirect impacts of Alternative 6 would be similar to Alternative 2, but would provide

fewer benefits. After accounting for 167 acres of direct impacts, Alternative 6 would

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reduce land loss in the project area from 101,570 acres to 101,563 acres, thus preventing

the loss of 7 acres of emergent marsh habitat over the 50-year period of analysis when

compared to the No Action Alternative.

Organism access to EFH could be impeded by the modified operation of the HNC lock

complex (CL1); however, other natural routes of movement (e.g. Bayou Grand Caillou)

would remain open.

5.10.6.3 Cumulative

Over the period of analysis, Alternative 6 would reduce land loss in the project area by 7

acres. When combined with CWPPRA and other Federal, state, local, and private

restoration efforts, Alternative 6 would have an even greater impact on EFH resources, as

those programs would work synergistically to improve habitat conditions across the

coast.

5.10.7 Alternative 7

5.10.7.1 Direct

No direct impacts to EFH are anticipated for Alternative 7.

5.10.7.2 Indirect

Alternative 7 would increase land loss in the project area from 101,570 acres to 104,221

acres, thus resulting in a net loss of 2,651 acres of emergent marsh habitat over the 50-

year period of analysis when compared to the No Action Alternative. Impediments to

organism access would result only from the modified operation of the lock complex

(CL1).

5.10.7.3 Cumulative

Cumulative impacts of Alternative 7 would be similar to Alternative 2, but to a lesser

degree.

5.10.8 Alternative 8

5.10.8.1 Direct

Implementation of Alternative 8 would result in some emergent wetland EFH being

directly converted to open water. These direct impacts would be the result of dredge

features CD1, CD6, ED3, and ED6 (Table 5.2). These features would impact a total of

270 acres of marsh habitat. These features would also impact 239 acres of open water

habitat. 41 acres of upland and open water habitat for temporary work areas would be

needed for construction of Alternative 8. Direct negative impacts to EFH would be offset

by the indirect benefits that Alternative 8 provides to high quality EFH (i.e. emergent

wetland and submerged aquatic vegetation) over much larger areas (see indirect benefits

below).

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5.10.8.2 Indirect

Indirect impacts of Alternative 8 on EFH would be similar to Alternative 2, but to a lesser

degree. Alternative 8 would reduce land loss in the project area from 101,570 acres to

100,581 acres, thus preventing the loss of 989 acres of marsh habitat over the 50-year

period of analysis when compared to the No Action Alternative.

Organism ingress and egress impacts due to feature WP1 would be eliminated under

Alternative 8. However, the modified operation of the lock complex (CL1) and the

Robinson Canal plug (CP1) would still impact organism movement.

5.10.8.3 Cumulative

Cumulative impacts of Alternative 8 on EFH would be similar to Alternative 2, but to a

lesser degree.

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5.11 Threatened and Endangered Species

Appendix A contains a Biological Assessment of threatened and endangered species and

the potential impacts of project implementation on those species.

5.11.1 No Action Alternative (Future without Project Conditions)

The No Action Alternative would result in the continued degradation and loss of

important and essential fish and wildlife habitats used by many different fish and wildlife

for shelter, nesting, feeding, roosting, cover, nursery, and other life requirements. The

loss and deterioration of transitional wetland habitats would continue to impact, to some

undetermined degree, all listed species that potentially utilize the project area including:

West Indian manatee, piping plover, pallid sturgeon, Gulf sturgeon, green sea turtle,

hawksbill sea turtle, Kemp’s Ridley sea turtle, leatherback sea turtle, and loggerhead sea

turtle. Adverse cumulative impacts on listed species would be offset, to some degree, by

the positive impacts of implementing other Federal, state, local, and private restoration

projects.

5.11.2 Alternative 2 (NER Plan and RP)

5.11.2.1 Direct

West Indian Manatee

Any effects to the West Indian manatee from implementing Alternative 2 would be

related to possible collision with service vessels during construction and maintenance

activities. Should any manatees be encountered during the proposed activities, an onboard observer would notify the proper personnel, and harmful activities (e.g., dredging)

would be temporarily suspended until the animal(s) moves out of the area of operations.

Any disturbance to the manatee would only be temporary during construction activities,

and would result in temporary displacement. The manatees would likely move and

relocate to other nearby areas for foraging or resting purposes. Because the West Indian

manatee may occur in the project vicinity, the Contractor shall instruct all personnel

associated with the project of the potential presence of manatees in the area, and the need

to avoid collisions with these animals. All construction personnel shall be advised that

there are civil and criminal penalties for harming, harassing, or killing manatees, which

are protected under the Marine Mammal Protection Act of 1972 and the Endangered

Species Act of 1973. The Contractor shall be held responsible for any manatee harmed,

harassed, or killed as a result of construction activities not conducted in accordance with

these specifications.

Piping Plover

It is possible that piping plovers may be found utilizing exposed sand, mud, or algal flats

in the southern portions of the proposed project boundaries. However, piping plovers are

more likely to be foraging and roosting on barrier island and barrier headland habitats

located farther south of the project boundaries. The project area is being located well

north of any designated critical habitat units for the piping plover. Accordingly, the

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proposed activities are not likely to adversely affect the piping plover (Ronald Paille,

USFWS personal communication 2010).

Pallid Sturgeon

While there are records of the pallid sturgeon occurring in the Atchafalaya River, there

are none for the project area itself (Schramm 2008; Paul Hartfield, USFWS personal

communication 2010; Jack Kilgore, ERDC personal communication 2010). The pallid

sturgeon is a river species that rarely travels into the marshes of the project area.

Diversion of water from the Atchafalaya River into the marshes will not appreciably

change the characteristics of the river. Accordingly, the proposed activities are not likely

to adversely affect the pallid sturgeon.

Gulf Sturgeon

The Gulf Sturgeon in the Gulf of Mexico is primarily found between Tampa Bay Florida

and the Mississippi River (Wooley 1985).Very few records exist for the Gulf sturgeon

occurring west of the Mississippi River (Wooley 1985; Todd Slack, ERDC personal

communication 2010). There is no critical habitat located in the project area. The project

is not likely to have an adverse effect on the Gulf Sturgeon due to its low probability of

occurrence and lack of suitable habitat in the project area.

Green Sea Turtle

Due to the lack of extensive seagrass beds in coastal Louisiana and the low incidence of

sightings and strandings, the proposed actions are not likely to adversely affect green sea

turtle populations.

Hawksbill Sea Turtle

Due to its rarity along the Louisiana coast, the proposed actions are not likely to

adversely impact hawksbill sea turtle populations.

Kemp’s Ridley Sea Turtle

Kemp’s Ridley sea turtles concentrate near the mouths of rivers and in areas of low

salinity with high turbidity to forage for prey, including shrimp. The proposed actions

are not likely to adversely impact Kemp’s Ridley sea turtle populations.

Leatherback Sea Turtle

Leatherback sea turtles occur mostly in continental shelf waters more than 164 ft (50 m)

in depth. There are no known nesting records for this species reported for Louisiana.

The proposed actions are not likely to adversely impact populations of leatherback sea

turtles.

Loggerhead Sea Turtle

The only loggerhead sea turtle nesting sites historically observed in Louisiana were on

the Chandeleur Islands. The proposed action would have no impacts on existing barrier

island habitats. Hence, the proposed actions are not likely to adversely impact

loggerhead sea turtle populations.

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5.11.2.2 Indirect

It is unlikely that any of the features associated with implementation of Alternative 2

would present significantly adverse indirect impacts to any threatened or endangered

species. On the contrary, all restoration features would likely provide a net increase of

coastal wetland habitats potentially used by these species.

5.11.2.3 Cumulative

There would be negligible, if any, negative impacts associated with implementation of

Alternative 2. Hence, based upon the potential direct, indirect, and cumulative impacts,

implementation of Alternative 2 is not likely to adversely affect threatened or endangered

species or their critical habitat.

5.11.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 on threatened and endangered

species and their critical habitat would be similar to Alternative 2.

5.11.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 on threatened and endangered

species and their critical habitat would be similar to Alternative 2.

5.11.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 on threatened and endangered

species and their critical habitat would be similar to Alternative 2.

5.11.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 on threatened and endangered

species and their critical habitat would be similar to Alternative 2.

5.11.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 on threatened and endangered

species and their critical habitat would be similar to Alternative 2.

5.11.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 on threatened and endangered

species and their critical habitat would be similar to Alternative 2.

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5.12 Cultural and Historic Resources

The complete cultural resources report can be found at Appendix F. In satisfaction of

Section 106 of the NHPA, a Programmatic Agreement (PA) between USACE-MVN,

SHPO, ACHP, and CPRA has been developed to address the needs of LCA projects

including Convey Atchafalaya River Water to North Terrebonne Marshes. Federally

recognized tribes, State tribes, and local governments have been invited to participate as

consulting parties. A copy of the PA appears at Appendix F. Appendix F also describes

the physiographic setting, geomorphic history and the previous research conducted within

the study area. Statistical modeling was used to examine correlations between settlement

and prominent landforms. A cost estimate for the archaeological surveys, monitoring,

etc., necessary to address the project’s direct impact on cultural resources is provided at

its conclusion.

There are eight (8) locations listed on the National Register than are within the project

boundary. There are an additional six (6) within a one kilometer radius of the area. Of

the National Register locations, only the Wesley House is located in close proximity to a

potential project feature being within 100 meters from features CC2 and CD4. A private

cemetery associated with the Wesley House is within the AOE of CD4 (see discussion of

the Gagne Cemetery at end of Appendix F).

Assuming a typical survey corridor of 100 meters, a total of 19,910 acres within the

proposed project area have been recorded as having undergone an archaeological survey.

This amounts to just under three percent of the total area. This number may be an

underestimate as many recorded sites fall outside the recorded survey tracks. Older

surveys may not be recorded on the maps of the Louisiana State Historical Preservation

Office from which this dataset was derived.

The vast majority of site record forms list “natural levee” as the landform associated with

the sites with no other single category representing any significant percentage. Site

correlation to regional-scale landforms was also undertaken within the project GIS. Site

features were spatially joined to a digitized version of a 1:500,000 scale Geologic Map of

Louisiana developed by the Louisiana Geological Survey. The relatively small scale of

the map led to some sites falling into obviously incorrect areas (e.g., known terrestrial

sites falling into the “water” category). Moreover, the map scale only allows the broadest

expression of landforms to be mapped. Natural levees, for example, are limited to major

ones located along the primary bayous. The number of sites located on “alluvium” and

“natural levees” is higher than what would have been expected given a random

distribution of sites across the landscape. A chi-squared goodness-of-fit test was

conducted to assess the statistical association between sites and the mapped landform.

Based upon the total area of the various geologic categories within the project area an

expected number of sites to be located within each category were generated. This

expected number of sites was compared to the known number and a chi-square test used

to assess the statistical significance of the difference. The results indicate that it is

statistically considered extremely unlikely that the distribution would have occurred

randomly. As the boundaries between “Fresh Marsh” and “Saline Marsh” categories

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were thought to be temporally sensitive they were combined and the analysis performed

again. Again, the difference in distributions was considered significant.

Given the statistics, it might be proposed that levees and areas of alluvium were

preferentially selected for site location by people. Other mitigating factors, however,

need to be taken into account. For example, the perceived preference of site location may

be simply be a function of where archaeological surveys have historically been

undertaken. Indeed, when the known geologic provenience of survey tracks are

themselves queried against a random landform distribution, the difference is consistently

statistically significant. The results are not dissimilar to site/geologic correlations with

“alluvium” and “natural levees” being over represented. In simple terms, at least some of

the apparent site location preferences are doubtless attributable to the bias for

archaeological surveys to be conducted on those landforms. To account for this survey

locational bias, a further couple of chi-square tests were performed using the survey

geological associations rather than the total project area associations. In this way, if site

associations with geologic categories are statistically different from the survey areas

association with those categories, it can be asserted that the site associations are not

solely attributable to the latter. Again, the two-tailed P value is considered significant.

This association of sites to levee and alluvial geological areas is not unexpected and

indeed, if anything, may be under-represented. An 1895 map of the region was digitized

and georeferenced for comparison to the geologic map. The areas in the historic map

without hatching represent natural levees and other elevated areas. The hatched areas

represent marsh lands (there named “prairie”). The elevated areas correspond well with

the areas designated “natural levee” on the geologic maps and to a lesser extent with

those designated “alluvium.” It is interesting, however, that the historic map shows the

levees extending much further south along the bayous than the geologic map.

Consequently, many sites that are associated with marsh land on the geologic map are

associated with natural levee land on the historic map. A clear example is the string of

sites along the lower Bayou du Large. Again, the chi-square statistic indicates that the

non-random correlation is highly significant.

It is clear from both the micro-scale landforms listed on the State Site Record Forms and

the macro-scale landform statistics presented above that the elevated landforms (i.e.,

natural levees and alluvium regions) are significantly more likely to contain

archaeological resources. As such, they are considered in this study as “higher

probability areas” while the delta marshes are considered “lower probability areas.”

Both the SHPO and Tribes were contacted by the St. Louis District Engineering and

Construction Division Curation and Archives Analysis Branch between mid-May and

early-June of 2009. SHPO notification is dated May 19, 2009 and was sent to the

attention of Mr. Scott Hutcheson, Office of Historic Preservation, Capitol Annex

Building, P.O. Box 44247, Baton Rouge, Louisiana 70804. Tribal notification was sent

by the district’s Native American Coordinator, Roberta L. Hayworth, to elected Tribal

Leaders and appointed Tribal Representatives for the following Nations.

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• Alabama Coushatta Tribe of Texas

• Caddo Nation of Oklahoma

• Chitimacha Tribe of Louisiana

• Choctaw Nation of Oklahoma

• Coushatta Tribe of Louisiana

• Jena Band of Choctaw

• Mississippi Band of Choctaw

• Quapaw Tribe of Oklahoma

• Seminole Nation of Oklahoma

• Seminole Tribe of Florida

• Tunica-Biloxi Tribe of Louisiana

No written responses to these notifications were received by the St. Louis District Office.

A notice of intent to prepare a draft EIS for this project was published in the Federal

Register (Vol. 73 No. 246) on December 22, 2008. Two public scoping meetings have

been held, first on February 3, 2009, and on the following day, February 4, 2009 in

Houma and Morgan City respectively. More than 350 media outlets were provided with

the advisory announcing these meetings.

Visits to the Baton Rouge Office of Historic Preservation were undertaken by St. Louis

District cultural resources POC, Susan Malin-Boyce, on February 19, 2009 and February

20, 2009 to meet with the Louisiana State Archaeologist and review survey reports for

the proposed project area. Subsequent meetings with the Louisiana State Archaeologist

were attended on July 1, 2009, and November 4, 2009. A draft copy of this report

Appendix was submitted to the Louisiana State Archaeologist for review and comment.

Disturbances to archaeological resources can result from both construction of project

features and the long-term operational effects of the features in an integrated system.

While construction disturbances are relatively straightforward to quantify, operational

disturbances are harder to measure at this juncture.

Construction Disturbances

Sixty-five project features are proposed in the current (December 11, 2009) range of

alternatives. These areas are expected to be disturbed by construction activity. A

subtotal of the various landform acreage affected is presented in Appendix F. The

numbers represent a sum for all the features from all project alternatives.

Operational Disturbances

While construction of individual project features has an immediate impact on their

surrounding environment, as an integrated system they are designed to affect the regional

environment at large. These “operational disturbances” are much more likely to affect

the cultural resources within the project area as they impact a much larger area than the

construction of individual features. Examples of such effects include increased erosion

of riverbanks and shorelines due to changing water flow patterns and increased

sedimentation or overburden. While the “burying” of archaeological resources is

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generally considered a benign, or even beneficial, effect, erosion shorelines or river banks

is a major concern as it may result in the destruction of cultural resources. At this point

in the projects feasibility study, it is not possible to model the effects of the operational

disturbance to archaeological resources over the long term.

Fourteen sites are located within 100 meters of a proposed project feature, as the latter are

represented within the project GIS. Two of the sites are within 10 meters and three are in

actual contact with a project feature. Two of the sites are described in their State Site

Record files as being “eligible” for listing in the National Register of Historic Places

(NRHP), five as “unknown” and seven as “not eligible.” A fifteenth site (16SMY49) was

identified as being located within 100 meters of a feature during GIS analysis. The site,

however, appears to be mapped incorrectly in the Louisiana State cultural resources GIS.

It is visible in satellite imagery to the north of its mapped location, both protected by a

breakwater and further than 100 meters from any proposed project features. Its physical

location was confirmed visually during the project area reconnaissance.

• Two hundred and ninety (290) known archaeological sites are located in the

project area as currently delineated.

• Many of these archaeological sites were recorded more than 20 years ago.

• There is a relative paucity of previously identified archaeological sites that have

yielded datable materials.

• Many sites that have reliable cultural associations were repeatedly occupied, so

for instance a site may have a Marksville (AD 1-400) occupation followed by

Baytown (AD 400-700) or Coles Creek (AD 700-1200), a Mississippian

occupation (AD 1200-1700), an early settler’s farm and then a modern plantation

– because these were significant places in human memory, and also they were

strategically located on high ground and next to distributary channels.

• Very few of the sites extend all the way back to the Poverty Point period (1000

BC to AD 1) and only a handful to the Marksville.

• Any site likely to be adversely impacted in the course of this project should be

carefully considered for the contribution it may make to an understanding of the

prehistory of this area.

• Sixty-seven (67) project features have been considered for adverse effect and

budgetary purposes.

• Fourteen (14) known archaeological sites are located within 100 meters of a

potential project feature.

• Thirteen residential structures and one recreational structure will require

evaluation depending on the alternate chosen as they will need to be relocated.

• The National Register of Historic Places (NRHP) lists eight (8) locations within

the project boundary.

• One (1) location listed on the NRHP (the Wesley House) is situated within 100

meters of a potential project feature.

• A small family cemetery of probably under ten (10) interments associated with

the Wesley House (the Gagne cemetery) is within the APE of a project feature.

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• Operational effects (secondary impacts) of project features on the archaeological

landscape have not been modeled for this feasibility study.

5.12.1 No Action Alternative (Future without Project Conditions)

5.12.1.1 Direct

Subsidence and erosion are ongoing throughout the project area. In Future without

Project Conditions site erosion processes and subsidence continue unabated.

5.12.1.2 Indirect

Same as direct.

5.12.1.3 Cumulative

Same as direct.

5.12.2 Alternative 2 (NER Plan and RP)

5.12.2.1 Direct

Twenty-seven construction features require Phase I testing and or monitoring. There are

eleven known archaeological sites within 100 m of features for which site assessments

are required. One historic period cemetery is located within the impact area.

Contingency must be allowed for Phase II or Phase III mitigation in the event that

unknown cultural resources are encountered during survey or construction.

5.12.2.2 Indirect

Long-term operational effects (secondary/indirect impacts) of project features on the

archaeological landscape have not been modeled for this feasibility study. The scale of

indirect impacts via erosion or site burial has not been determined because there is risk

and uncertainty in the hydrologic influence that cannot be anticipated.

5.12.2.3 Cumulative

Cumulative impacts cannot be predicted with the current state of available information.

5.12.3 Alternative 3

5.12.3.1 Direct

Twenty-seven construction features require Phase I testing and or monitoring. There are

thirteen known archaeological sites within 100 m of features for which site assessments

are required. One historic period cemetery is located within the impact area.

Contingency must be allowed for Phase II or Phase III mitigation in the event that

unknown cultural resources are encountered during survey or construction.

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5.12.3.2 Indirect

Long-term operational effects (secondary/indirect impacts) of project features on the

archaeological landscape have not been modeled for this feasibility study. The scale of

indirect impacts via erosion or site burial has not been determined because there is risk

and uncertainty in the hydrologic influence that cannot be anticipated.

5.12.3.3 Cumulative

Cumulative impacts cannot be predicted with the current state of available information.

5.12.4 Alternative 4

5.12.4.1 Direct

Twenty-eight construction features require Phase I testing and or monitoring. There are

twelve known archaeological sites within 100 m of features for which site assessments

are required. One historic period cemetery is located within the impact area.

Contingency must be allowed for Phase II or Phase III mitigation in the event that

unknown cultural resources are encountered during survey or construction.

5.12.4.2 Indirect

Long-term operational effects (secondary/indirect impacts) of project features on the

archaeological landscape have not been modeled for this feasibility study. The scale of

indirect impacts via erosion or site burial has not been determined because there is risk

and uncertainty in the hydrologic influence that cannot be anticipated.

5.12.4.3 Cumulative

Cumulative impacts cannot be predicted with the current state of available information.

5.12.5 Alternative 5

5.12.5.1 Direct

Twenty-eight construction features require Phase I testing and or monitoring. There are

fourteen known archaeological sites within 100 m of features for which site assessments

are required. One historic period cemetery is located within the impact area.

Contingency must be allowed for Phase II or Phase III mitigation in the event that

unknown cultural resources are encountered during survey or construction.

5.12.5.2 Indirect

Long-term operational effects (secondary/indirect impacts) of project features on the

archaeological landscape have not been modeled for this feasibility study. The scale of

indirect impacts via erosion or site burial has not been determined because there is risk

and uncertainty in the hydrologic influence that cannot be anticipated.

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5.12.5.3 Cumulative

Cumulative impacts cannot be predicted with the current state of available information.

5.12.6 Alt Alternative 6

5.12.6.1 Direct

Six construction features require Phase I testing and or monitoring. There are nine

known archaeological sites within 100 m of features for which site assessments are

required. One historic period cemetery is located within the impact area. Contingency

must be allowed for Phase II or Phase III mitigation in the event that unknown cultural

resources are encountered during survey or construction.

5.12.6.2 Indirect

Long-term operational effects (secondary/indirect impacts) of project features on the

archaeological landscape have not been modeled for this feasibility study. The scale of

indirect impacts via erosion or site burial has not been determined because there is risk

and uncertainty in the hydrologic influence that cannot be anticipated.

5.12.6.3 Cumulative

Cumulative impacts cannot be predicted with the current state of available information.

5.12.7 Alternative 7

5.12.7.1 Direct

Report preparation for cultural resources literature review, and historic context and

contingency allowance for testing and mitigation in the event that unknown cultural

resources are encountered during construction or develop from the lock operation.

5.12.7.2 Indirect

Long-term operational effects (secondary/indirect impacts) of project features on the

archaeological landscape have not been modeled for this feasibility study. The scale of

indirect impacts via erosion or site burial has not been determined because there is risk

and uncertainty in the hydrologic influence that cannot be anticipated.

5.12.7.3 Cumulative

Cumulative impacts cannot be predicted with the current state of available information.

5.12.8 Alternative 8

5.12.8.1 Direct

Eighteen construction features require Phase I testing and or monitoring. There are four

known archaeological sites within 100 m of features for which site assessments are

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required. Contingency must be allowed for Phase II or Phase III mitigation in the event

that unknown cultural resources are encountered during survey or construction.

5.12.8.2 Indirect

Long-term operational effects (secondary/indirect impacts) of project features on the

archaeological landscape have not been modeled for this feasibility study. The scale of

indirect impacts via erosion or site burial has not been determined because there is risk

and uncertainty in the hydrologic influence that cannot be anticipated.

5.12.8.3 Cumulative

Cumulative impacts cannot be predicted with the current state of available information.

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5.13 Aesthetics

5.13.1 No Action Alternative (Future without Project Conditions)

Loss of visual resources in the study area would continue under the No Action

Alternative due to the incremental loss of wetlands and the natural ridges from sea level

rise, subsidence and erosion. Wetland and shoreline erosion and associated wetland

fragmentation’s conversion to open water may negatively affect the viewsheds within

Mandalay National Wildlife Refuge and Pointe au Chiene Wildlife Management Area

and along the Southern portions of the Wetlands Cultural Scenic Byway. Opportunities

for visual use including wildlife observation, environmental interpretation and cultural

awareness will diminish if the marsh and natural ridges erode.

Cumulative impacts to visual resources under the No Action Alternative would be due to

the historical and future incremental loss of wetlands and the natural ridges regionally

and nationwide due to sea level rise, subsidence and erosion . Wetland and shoreline

erosion and associated wetland fragmentation’s conversion to open water may negatively

affect the viewsheds within significant visual resources including wildlife refuges and

management areas and scenic streams and byways. Opportunities for visual use

including wildlife observation, environmental interpretation and cultural awareness will

diminish with the erosion of marsh and natural ridges.

5.13.2 Alternative 2 (NER Plan and RP)

5.13.2.1 Direct

Direct impacts to visual resources may occur as the result of culvert construction and

dredging operations at the intersection of Bayou Terrebonne and the GIWW in Houma.

Public facilities including a parking area, marina, gazebos, and walking paths may allow

visual access from the west side of the GIWW to the proposed project area from the

North and South sides of Bayou Terrebonne; project construction details are insufficient

to determine the magnitude of impacts to this visual resource.

5.13.2.2 Indirect

Visual resources in the study area indirectly impacted under the proposed action would

be due to enhanced and stabilized marsh and stabilized natural ridges. In particular, the

enhanced and stabilized marsh and stabilized natural ridges may be beneficial to

Mandalay National Wildlife Refuge and Pointe au Chien Wildlife Management Area and

along the Southern portions of the Wetlands Cultural Scenic Byway. Increased

opportunities for visual use including wildlife observation, environmental interpretation

and cultural awareness may occur.

5.13.2.3 Cumulative

Cumulative impacts to visual resources under the proposed action may be due to similar

projects that enhance and stabilize marsh and stabilize natural ridges regionally and

nationwide. Wetland and shoreline erosion and associated wetland fragmentation’s

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conversion to open water may be reversed beneficially affecting the viewsheds within

significant visual resources including wildlife refuges and management areas and scenic

streams and byways. Opportunities for visual use including wildlife observation,

environmental interpretation and cultural awareness may increase with enhanced marsh

and not diminish with stabilized marsh and natural ridges.

5.13.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 on Aesthetics would generally

be similar to Alternative 2.

5.13.4 Alternative 4

5.13.4.1 Direct

Alternative 4 would have direct impacts similar to Alternative 2.

5.13.4.2 Indirect

Alternative 4 would have indirect impacts similar to Alternative 2 on the visual resources

within Mandalay Wildlife refuge and along the southern portions of the Wetlands

Cultural Scenic Byway. Alternative 4 would enhance and stabilize marsh in Pointe au

Chien Wildlife Management Area more than Alternative 2.

5.13.4.3 Cumulative

Alternative 4 would have cumulative impacts similar to Alternative 2.

5.13.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 on Aesthetics would generally

be similar to Alternative 4.

5.13.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 on Aesthetics would generally

be similar to Alternative 2.

5.13.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 on Aesthetics would generally

be similar to Alternative 2.

5.13.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 on Aesthetics would generally

be similar to Alternative 2.

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5.14 Recreation

5.14.1 No Action Alternative (Future without Project Conditions)

Recreational resources in the entire region that would most likely be impacted under the

No Action Alternative are those related to loss of wetlands and habitat diversity as well

as substantial salinity changes. In the West region, wetlands and associated marsh habitat

appear generally more stable than the Central and East regions due to freshwater and

sediment provided by the Atchafalaya River, which is in close proximity. However,

some portions of the West region, specifically the lower southeast portions are

experiencing wetland loss and fragmentation. Under the No Action Alternative, in the

West region, the floating marsh habitat, intermediate and brackish marsh habitat would

continue to provide freshwater and saltwater based recreational opportunities, such as

waterfowl hunting and fishing. However, over time, land and habitat loss and associated

changes in salinity levels encroaching from the southeast could begin to negatively affect

both freshwater and saltwater based fishing as well as waterfowl hunting.

By taking no action, continued saltwater intrusion, wetland and shoreline erosion and

associated wetland fragmentation and conversion to open water will likely continue in the

Central and East regions with negative impacts on recreation resources. As marsh habitat

decreases, areas for fish spawning decrease and ultimately the populations and diversity

of fish species will diminish, which would affect recreational fishing opportunities

negatively. Similarly, with less freshwater and intermediate marsh habitat, waterfowl

hunting opportunities would likely decrease. Ridge habitat would also likely continue to

decline, reducing opportunities for deer and other small game hunting.

Long term impacts specifically in the Central and East regions may include loss of

associated recreational support facilities such as marinas and bait shops that are the basis

for most recreational use. This would result in a reduction in economic activity

associated with recreation uses.

Cumulative impacts are the impacts on the environment that will result from the

incremental impact of the No Action Alternative from the other past, present, and

reasonably foreseeable future actions regardless of what agency or person undertakes

such other actions. Existing and planned projects in the project vicinity include those

supported by various sources including, but not limited to, the Coastal Wetlands

Planning, Protection and Restoration Act (CWPPRA) and the U. S. Army Corps of

Engineers (USACE). However, the impacts of these other projects do not extend to the

entire 1,100 square mile area that is the study area. Despite these other efforts, continued

coastal erosion and increased levels of salinity would likely occur throughout much of the

project area.

Localized beneficial impacts may include improved habitat and protection for fish and

wildlife habitat during coastal storms due to the water control structures; protection of

new lands for hunting; and a walking path for hunters and sightseers on the perimeter of

the Pointe Au Chien WMA associated with the USACE Morganza to the Gulf Hurricane

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Protection project. The CWPPRA West Lake Boudreaux Shoreline Protection and Marsh

Creation project will provide additional nursery habitat for fish and improved food supply

for waterfowl.

Other recent projects in the area had similar purposes and would similarly benefit

recreation by improving fish and wildlife habitat. The Avoca Island Diversion and Land

Building Project (CWPPRA Project Number TE-49) was approved in 2003 to divert

freshwater, sediment, and nutrients from Bayou Shaffer to rebuild eroded wetlands of the

Avoca Lake area. The Avoca Island Marsh Restoration project funded through The

North American Wetlands Conservation Act was scheduled to begin in summer 2005 to

restore coastal marsh. The GIWW Bankline Restoration Project was approved for

funding through the Natural Resources Conservation Service in 2003 to protect wetland

habitat and protect emerging freshwater floating marsh.

5.14.2 Alternative 2 (NER Plan and RP)

5.14.2.1 Direct

Closure of the gate structure at the HNC lock complex and installation of the Robinson

Canal plug would result in reduced accessibility from boat launch sites to recreational

resources. If recreational resources cannot be accessed, the commercial boat launches

which support recreation would potentially experience a reduction in use and economic

activity. The potential impact from closure of the HNC gate structure may be minimized

with a system established to notify recreational users of lock and gate operations

schedules. Other direct impacts would primarily be displacement of recreationists due to

construction of project features.

5.14.2.2 Indirect

Alternative 2 would increase distribution of water to the southeast portion of the

Penchant marshes with a dredge channel. The Penchant marshes are high quality floating

marsh habitat providing prime freshwater based recreational activities including bass

fishing and waterfowl hunting.

West Region

Potential positive effects of increased freshwater flows include marsh nourishment

around the Penchant basin marshes and pushing freshwater further south and east to

nourish and stabilize deteriorating fresh, intermediate and brackish marsh in the east and

south portions of the West region.

However, periods of high flow of freshwater would likely result in temporary increases in

turbidity and reduced water quality, which may reduce recreational fishing and waterfowl

hunting opportunities during these high flow periods.

In the Central region a system of flow management features would help alleviate GIWW

constrictions and increase fresh water flow from north to south into the North Lake

Central Region

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Boudreaux system. The potential impacts from redistribution of freshwater and the

associated features would be similar to those effects in the West region.

Freshwater flows may result in some reduction in salinity levels, and help to stabilize

fresh, intermediate, and brackish marsh in and around Lake Boudreaux and the Central

region, stabilizing and improving habitat for waterfowl, which in turn, would enhance

waterfowl hunting opportunities. Freshwater based recreational fishing should improve

and current levels of recreational saltwater fishing would possibly be maintained.

As in the West and Central regions, improved freshwater flow measures would have

similar effects to recreational resources as described for the Central region. In particular,

bird watching, recreational fishing, and shrimping at Pointe Au Chien WMA would

benefit as additional freshwater from the improved flow measures would improve habitat

for all of these species.

East Region

With this alternative, no substantial change in recreational user days is anticipated

through year 50. AAHUs provided by saline, brackish, intermediate and fresh marshes

under this alternative are expected to rise by 3,220. Overall this alternative should help

to stabilize or improve freshwater based recreational activities such as waterfowl hunting,

while maintaining current saltwater based recreational opportunities.

5.14.2.3 Cumulative

The cumulative impacts of Alternative 2 and other planned or ongoing measures will be

stabilization and potential enhancement of wetlands and marsh habitat throughout the

study area. Some reduction in overall salinity levels is also anticipated. Planned and ongoing measures along with Alternative 2 project measures will likely be beneficial to the

ecosystem and to recreation resources in numerous ways as habitat for various stages in

the life-cycles of fish and wildlife are stabilized, protected, improved, and expanded.

Improved fish habitat will increase the numbers and variety of fish, which will be

beneficial to recreational fishing. Similarly, marsh and ridge restoration will improve

vegetation and habitat for birds and wildlife and will enhance opportunities for birding,

hunting, and hiking. Stabilization and enhancement of fresh and intermediate marsh

should enhance waterfowl hunting.

However, the temporary effects of planned, ongoing, and proposed measures would

include turbidity and associated reductions in water quality. This may result in some

short-term reduction in freshwater and saltwater based recreation opportunities.

Beneficial impacts to recreational resources are expected to ultimately outweigh the

negative, temporary impacts due to project construction. These projects will likely

stabilize and potentially enhance recreational resources and associated economic activity

well into the future.

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5.14.3 Alternative 3

5.14.3.1 Direct

Alternative 3 direct impacts would be similar to those described for Alternative 2.

5.14.3.2 Indirect

Alternative 3 indirect impacts would be similar to those described for Alternative 2.

5.14.3.3 Cumulative

Alternative 3 cumulative impacts would be similar to those described for Alternative 2.

5.14.4 Alternative 4

5.14.4.1 Direct

Closure of the gate structure at the HNC lock complex, installation of the Robinson Canal

plug, and installation of the Bayou L’Eau Blue plug would result in reduced accessibility

from boat launch sites to recreational resources. If recreational resources cannot be

accessed, the commercial boat launches which support recreation would potentially

experience a reduction in use and economic activity. The potential impact from closure

of the HNC gate structure may be minimized with a system established to notify

recreational users of lock and gate operations schedules. Other direct impacts would

primarily be displacement of recreationists due to construction of project features.

5.14.4.2 Indirect

Alternative 4 indirect impacts would be similar to those described for Alternative 2 for

the West and Central region. However for the East region, increased inflow of freshwater

via the Grand Bayou Pump feature is introduced.

Substantial increases in freshwater flows into the Grand Bayou watershed would nourish

and stabilize fresh, intermediate, and brackish marsh, and enhance habitat for fish and

waterfowl. During high flow periods, turbidity and associated poor water quality would

potentially reduce both freshwater and saltwater recreational fishing and waterfowl

hunting opportunities including similar impacts in the Pointe Au Chien WMA.

Potentially positive effects to recreational fishing and hunting attributable to increased

supply of freshwater would be improved additional nursery habitat for fish and improved

food supply for waterfowl.

East Region

With Alternative 4, no substantial change in recreational user days is anticipated through

year 50. AAHUs provided by saline, brackish, intermediate and fresh marshes under this

alternative are expected to rise by 4,258, slightly higher than Alternatives 2 and 3.

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5.14.4.3 Cumulative

Alternative 4 would have similar cumulative impacts to Alternative 2.

5.14.5 Alternative 5

5.14.5.1 Direct

Alternative 5 would have similar direct impacts to Alternative 4.

5.14.5.2 Indirect

Alternative 5 indirect impacts would be similar to those described in Alternative 4.

With Alternative 5, no substantial change in recreational user days is anticipated through

year 50. However, among the alternatives, this alternative does result in the highest

potential increase in AAHUs of 4,719.

5.14.5.3 Cumulative

Alternative 5 would have similar cumulative impacts to Alternative 2. However, it would

provide the best opportunity to stabilize or improve freshwater based recreational

activities in the project area while maintaining and possibly enhancing saltwater based

recreational opportunities.

5.14.6 Alternative 6

5.14.6.1 Direct

Closure of the gate structure at the HNC lock complex would result in reduced

accessibility from boat launch sites to recreational resources. If recreational resources

cannot be accessed while the gate is closed, the commercial boat launches, which support

recreation, would potentially experience a reduction in use and economic activity. This

potential impact may be minimized with a system established to notify recreational users

of lock and gate operations schedules. Other direct impacts would primarily be

displacement of recreationists due to construction of project features.

5.14.6.2 Indirect

Potential positive effects of increased freshwater flows include marsh nourishment and

stabilization around the Penchant basin marshes. However, the ability to redistribute

water to the deteriorating fresh, intermediate and brackish marsh in the east and south

portions of the West region would be limited without flow management measures. In

turn, habitat enhancements beneficial to recreational fishing and waterfowl hunting

would be limited compared to Alternatives 2, 3, 4 and 5.

West Region

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However, periods of high flow of freshwater would likely result in temporary increases in

turbidity and reduced water quality, which may reduce recreational fishing and waterfowl

hunting opportunities during these high flow periods.

Increased freshwater flows may help to stabilize some of the fresh, intermediate and

brackish marsh in and around Lake Boudreaux and the Central region. However, the

ability to effectively redistribute freshwater will be limited without flow management

features. In turn, overall stabilization and enhancement of fisheries and waterfowl habitat

would be limited compared to Alternatives 2, 3, 4 and 5.

Central Region

Similar impacts to those described in the West and Central regions would be likely in the

East region.

East Region

Overall, with Alternative 6, no substantial change in recreational user days is anticipated

through year 50. However, the AAHUs provided by saline, brackish, intermediate and

fresh marshes under this alternative are expected to rise by 780, considerably lower than

Alternatives 2, 3, 4 and 5.

5.14.6.3 Cumulative

Overall cumulative impacts under Alternative 6 are similar to those described under

Alternative 2. However, even with the ecosystem restoration benefits of the other

ongoing and planned projects this alternative would likely provide the least benefit to the

recreational resource base due to reduced habitat stabilization and enhancement for fish

and wildlife resources as compared to Alternatives 2, 3, 4, 5, and 8.

5.14.7 Alternative 7

5.14.7.1 Direct

Closure of the gate structure at the HNC lock complex would result in reduced

accessibility from boat launch sites to recreational resources. If recreational resources

cannot be accessed while the gate is closed, the commercial boat launches, which support

recreation, would potentially experience a reduction in use and economic activity. This

potential impact may be minimized with a system established to notify recreational users

of lock and gate operations schedules.

5.14.7.2 Indirect

Overall, with Alternative 7, no substantial change in recreational user days is anticipated

through year 50. However, the AAHUs provided by saline, brackish, intermediate and

fresh marshes under this alternative are expected to rise by only 243, considerably lower

than Alternatives 2, 3, 4, 5, 6, and 8.

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5.14.7.3 Cumulative

Overall cumulative impacts under Alternative 7 are similar to those described under

Alternative 2. However, even with the ecosystem restoration benefits of the other

ongoing and planned projects this alternative would likely provide the least benefit to the

recreational resource base due to reduced habitat stabilization and enhancement for fish

and wildlife resources as compared to Alternatives 2, 3, 4, 5, 6, and 8.

5.14.8 Alternative 8

5.14.8.1 Direct

Alternative 8 would have similar direct impacts to Alternative 2.

5.14.8.2 Indirect

Alternative 8 involves no features in the West region and no indirect impacts are

anticipated.

West Region

In the Central region a system of flow management features would increase fresh water

flow from north to south into the North Lake Boudreaux system. Freshwater flows may

result in some reduction in salinity levels, and help to stabilize fresh, intermediate, and

brackish marsh in and around Lake Boudreaux and the Central region, stabilizing and

improving habitat for waterfowl, which in turn, would enhance waterfowl hunting

opportunities. Freshwater based recreational fishing should improve and current levels of

recreational saltwater fishing would possibly be maintained.

Central Region

Improved freshwater flow measures would have similar effects to recreational resources

as described for the Central region. In particular, bird watching, recreational fishing, and

shrimping at Pointe Au Chien WMA would benefit as additional freshwater from the

improved flow measures would improve habitat for all of these species.

East Region

Overall, with Alternative 8, no substantial change in recreational user days is anticipated

through year 50. AAHUs provided by saline, brackish, intermediate and fresh marshes

under this alternative are expected to rise by 1,214, considerably lower than Alternatives

2, 3, 4 and 5.

5.14.8.3 Cumulative

Overall cumulative impacts under Alternative 8 are similar to those described under

Alternative 2. However, even with the ecosystem restoration benefits of the other

ongoing and planned projects this alternative would likely provide the least benefit to the

recreational resource base due to reduced habitat stabilization and enhancement for fish

and wildlife resources as compared to Alternatives 2, 3, 4, and 5.

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5.15 Socioeconomics and Human Resources

5.15.1 Displacement of Population and Housing

5.15.1.1 No Action Alternative (Future without Project Conditions)

As inland marshes and barrier islands erode or subside in the Future Without-Project

conditions the resultant threatened population in the coastal communities is expected to

shift to the more northern portions of the coastal parishes. As these populations get

dispersed and absorbed into other geographic areas, their heritage and cultural way of life

could also be threatened.

Overall, the population of Lafourche, St. Mary, and Terrebonne Parishes increased from

105,953 to 247,685 from 1940 to 2000. This population is expected to increase to

approximately 261,000 by 2030 (Blanchard 2009). It is expected that this growth rate

will occur with or without the project in place. The exact location of the population

growth and shift would be influenced by many factors including land availability, flood

protection, and improvements to the transportation network.

5.15.1.2 Alternative 2 (NER Plan and RP)

5.15.1.2.1 Direct

Implementation of Alternative 2 would require the acquisition of 2,313 acres of

permanent right-of-way for placement of project features, 585 acres of temporary rightof-way for construction, and would require relocation of 13 residential structures and 1

recreational structure. The residential and recreational structure relocations are

associated with features CD2, CD4, CD6, ED2, and ED5. See Appendix J, Real Estate

Plan for more information on rights-of-way and relocations.

5.15.1.2.2 Indirect

Shifts in coastal population patterns, as affected by deterioration of coastal habitats, could

be slower than the Future without Project condition. Project implementation would

change salinity levels in fisheries areas, causing some species to relocate. As a result,

subsistence fishermen would potentially have to relocate to follow these resources or

change to other means of subsistence.

5.15.1.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater impact on coastal habitat, as those

programs would work synergistically to improve habitat conditions across the area,

potentially leading to a slower population shift away from coastal areas as compared to

the No Action Alternative.

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5.15.1.3 Alternative 3

5.15.1.3.1 Direct

Implementation of Alternative 3 would require the acquisition of 2,465 acres of

permanent right-of-way for placement of project features, 686 acres of temporary rightof-way for construction, and would require relocation of 13 residential structures and 1

recreational structure. The residential and recreational structure relocations are

associated with features CD2, CD4, CD6, ED2, and ED5. See Appendix J, Real Estate

Plan for more information on rights-of-way and relocations.

5.15.1.3.2 Indirect

Indirect impacts to population and housing would generally be similar to Alternative 2

but to a greater degree.

5.15.1.3.3 Cumulative

Cumulative impacts to population and housing would generally be similar to Alternative

2 but to a greater degree.

5.15.1.4 Alternative 4

5.15.1.4.1 Direct

Implementation of Alternative 4 would require the acquisition of 2,314 acres of

permanent right-of-way for placement of project features, 585 acres of temporary rightof-way for construction, and would require relocation of 13 residential structures and 1

recreational structure. The residential and recreational structure relocations are

associated with features CD2, CD4, CD6, ED2, and ED5. See Appendix J, Real Estate

Plan for more information on rights-of-way and relocations.

5.15.1.4.2 Indirect

Indirect impacts to population and housing would generally be similar to Alternative 2

but to a greater degree.

5.15.1.4.3 Cumulative

Cumulative impacts to population and housing would generally be similar to Alternative

2 but to a greater degree.

5.15.1.5 Alternative 5

5.15.1.5.1 Direct

Implementation of Alternative 5 would require the acquisition of 2,466 acres of

permanent right-of-way for placement of project features, 686 acres of temporary rightof-way for construction, and would require relocation of 13 residential structures and 1

recreational structure. The residential and recreational structure relocations are

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associated with features CD2, CD4, CD6, ED2, and ED5. See Appendix J, Real Estate

Plan for more information on rights-of-way and relocations.

5.15.1.5.2 Indirect

Indirect impacts to population and housing would generally be similar to Alternative 2

but to a greater degree.

5.15.1.5.3 Cumulative

Cumulative impacts to population and housing would generally be similar to Alternative

2 but to a greater degree.

5.15.1.6 Alternative 6

5.15.1.6.1 Direct

Implementation of Alternative 6 would require the acquisition of 1,080 acres of

permanent right-of-way for placement of project features, 117 acres of temporary rightof-way for construction, and would require relocation of 10 residential structures and 1

recreational structure. The residential and recreational structure relocations are

associated with features CD4 and ED5. See Appendix J, Real Estate Plan for more

information on rights-of-way and relocations.

5.15.1.6.2 Indirect

Indirect impacts to population and housing would generally be similar to Alternative 2

but to a lesser degree.

5.15.1.6.3 Cumulative

Cumulative impacts to population and housing would generally be similar to Alternative

2 but to a lesser degree.

5.15.1.7 Alternative 7

5.15.1.7.1 Direct

There would be no direct impacts to population and housing with implementation of

Alternative 7.

5.15.1.7.2 Indirect

Indirect impacts to population and housing would generally be similar to Alternative 2

but to a lesser degree.

5.15.1.7.3 Cumulative

Cumulative impacts to population and housing would generally be similar to Alternative

2 but to a lesser degree.

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5.15.1.8 Alternative 8

5.15.1.8.1 Direct

Implementation of Alternative 8 would require the acquisition of 742 acres of permanent

right-of-way for placement of project features, 41 acres of temporary right-of-way for

construction, and would require relocation of 2 residential structures and 1 recreational

structure. The residential and recreational structure relocations are associated with

features CD2, CD6, and ED5. See Appendix J, Real Estate Plan for more information on

rights-of-way and relocations.

5.15.1.8.2 Indirect

Indirect impacts to population and housing would generally be similar to Alternative 2

but to a lesser degree.

5.15.1.8.3 Cumulative

Cumulative impacts to population and housing would generally be similar to Alternative

2 but to a lesser degree.

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5.15.2 Employment and Income

5.15.2.1 No Action Alternative (Future without Project Conditions)

Slow growth in employment is expected to occur as the economy improves without the

proposed plan in place. The prospects of income opportunities may decline as well in the

rural areas if they experience continued depletion of their natural resources. Without the

implementation of the plan, residents and businesses may decide to move further inland

to avoid the effects of periodic hurricanes and tropical storms. Economic activity related

to wetland resources would also be adversely affected by the depletion of these resources.

5.15.2.2 Alternative 2 (NER Plan and RP)

5.15.2.2.1 Direct

Some short-term positive impacts to employment and income from implementation of

Alternative 2 would occur due to an increase in construction-related employment in the

project area.

5.15.2.2.1 Indirect

Over the 50-year period of analysis Alternative 2 would protect, create, and nourish

project area marshes resulting in a net benefit of 3,220 AAHUs over the No Action

Alternative. Protection of project area wetlands would benefit, to some undetermined

level, local employment in wetland-dependent jobs such as commercial and recreational

fisheries and ecotourism as well as provide benefits for supporting economic activities

such as marinas, bait and tackle shops, and others. In addition, the vast oil and gas

industry infrastructure in the project area would be better protected, benefitting local

employment.

5.15.2.2.1 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater impact on coastal habitat, as those

programs would work synergistically to improve habitat conditions across the area,

potentially leading to greater benefits for local employment impacted by coastal marshes.

5.15.2.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree. Over the 50-year period of analysis, Alternative 3

would result in 3,325 AAHUs over the No Action Alternative.

5.15.2.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would be generally similar to

Alternative 2 but to a greater degree. Over the 50-year period of analysis, Alternative 4

would result in 4,258 AAHUs over the No Action Alternative.

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5.15.2.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2 but to a greater degree. Over the 50-year period of analysis, Alternative 5

would result in 4,719 AAHUs over the No Action Alternative.

5.15.2.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2 but to a lesser degree. Over the 50-year period of analysis, Alternative 6

would result in 776 AAHUs over the No Action Alternative.

5.15.2.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

Alternative 2 but to a lesser degree. Over the 50-year period of analysis, Alternative 7

would result in 243 AAHUs over the No Action Alternative.

5.15.2.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2 but to a lesser degree. Over the 50-year period of analysis, Alternative 8

would result in 1,214 AAHUs over the No Action Alternative.

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5.15.3 Infrastructure

5.15.3.1 Business and Industry

5.15.3.1.1 No Action Alternative (Future without Project Conditions)

Business and industry in the project area would continue to be negatively impacted by

land loss, particularly those businesses and industries with infrastructure in the coastal

marshes (e.g. oil and gas) or those that depend on coastal marshes (e.g. commercial

fishing). Business and industry protected by storm damage reduction structures may

become more vulnerable due to the loss of protection afforded by coastal marshes.

5.15.3.1.2 Alternative 2 (NER Plan and RP

5.15.3.1.2.1 Direct

Some short-term positive impacts to business and industry from implementation of

Alternative 2 would occur due to an increase in construction-related employment in the

project area.

5.15.3.1.2.2 Indirect

Implementation of Alternative 2 would provide indirect benefits to Business and Industry

by decreasing the rate of decline of coastal marshes in the project area. Damage to oil

and gas infrastructure located within the coastal marshes due to undermining, anchor

dragging, etc. would be reduced. Commercial fishing dependent upon project area

marshes would benefit from the decreased rate of decline. Other business and industry

would benefit from the added storm damage protection afforded by coastal marshes.

5.15.3.1.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater impact on Business and Industry, as

those programs would work synergistically to improve habitat conditions across the

coast.

5.15.3.1.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would be generally similar to

those of Alternative 2, but to a greater degree.

5.15.3.1.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would be generally similar to

those of Alternative 2, but to a greater degree.

5.15.3.1.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would be generally similar to

those of Alternative 2, but to a greater degree.

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5.15.3.1.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would be generally similar to

those of Alternative 2, but to a lesser degree.

5.15.3.1.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would be generally similar to

those of Alternative 2, but to a lesser degree.

5.15.3.1.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would be generally similar to

those of Alternative 2, but to a lesser degree.

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5.15.3.2 Transportation

5.15.3.2.1 No Action Alternative (Future without Project Conditions)

Major transportation routes through the project area would likely not change significantly

in the Future Without Project condition. Transportation routes on distributary ridges may

become more vulnerable as subsidence continues. Protection from tropical storm and

hurricane damage provided by coastal marshes would continue to decrease. Navigation

impacts are covered in Section 5.15.6.

5.15.3.2.2 Alternative 2 (NER Plan and RP)

5.15.3.2.2.1 Direct

Direct impacts to Transportation from implementation of Alternative 2 would be

relatively minor and short-term. There would be some localized increases in congestion

on roadways due to construction equipment associated with the various features of

Alternative 2. The installation of water control structures under LA 24 and LA 57, as

well as other parish and private roads, could result in traffic delays and some disruption

of normal traffic flow. However, all direct impacts would be temporary in nature.

Traffic patterns would be expected to return to normal subsequent to completion of

construction.

5.15.3.2.2.2 Indirect

Implementation of Alternative 2 would provide indirect benefits to Transportation by

decreasing the rate of decline of coastal marshes in the project area. Transportation

routes susceptible to erosion from tropical storms and hurricanes would see some benefit

in the additional marsh acreage provided by Alternative 2.

5.15.3.2.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater impact on Transportation, as those

programs would work synergistically to improve habitat conditions across the area.

Alternative 2 would also contribute to the negative impacts on traffic congestion on area

roadways when combined with other similar transportation route construction projects.

5.15.3.2.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would be generally similar to

Alternative 2, but to a greater degree.

5.15.3.2.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would be generally similar to

Alternative 2, but to a greater degree.

5.15.3.2.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would be generally similar to

Alternative 2, but to a greater degree.

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5.15.3.2.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would be generally similar to

Alternative 2, but to a lesser degree.

5.15.3.2.7 Alternative 7

5.15.3.2.7.1 Direct

No direct impacts to Transportation are anticipated for Alternative 7. Impacts to

Navigation are covered in Section 5.15.6.

5.15.3.2.7.2 Indirect

Indirect impacts of Alternative 7 would generally be similar to Alternative 2, but to a

lesser degree.

5.15.3.2.7.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 7 would have an even greater impact on Transportation, as those

programs would work synergistically to improve habitat conditions across the area.

5.15.3.2.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would be generally similar to

Alternative 2, but to a lesser degree.

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5.15.3.3 Public Facilities and Services

5.15.3.3.1 No Action Alternative (Future without Project Conditions)

Under the No Action Alternative, public facilities and services, including schools,

hospitals, police and fire protection, levees and pump stations, etc. would continue to be

available to residents in the project area.

5.15.3.3.2 Alternative 2 (NER Plan and RP))

No impacts on public facilities and services are anticipated with implementation of

Alternative 2.

5.15.3.3.3 Alternative 3

No impacts on public facilities and services are anticipated with implementation of

Alternative 3.

5.15.3.3.4 Alternative 4

No impacts on public facilities and services are anticipated with implementation of

Alternative 4.

5.15.3.3.5 Alternative 5

No impacts on public facilities and services are anticipated with implementation of

Alternative 5.

5.15.3.3.6 Alternative 6

No impacts on public facilities and services are anticipated with implementation of

Alternative 6.

5.15.3.3.7 Alternative 7

No impacts on public facilities and services are anticipated with implementation of

Alternative 7.

5.15.3.3.8 Alternative 8

No impacts on public facilities and services are anticipated with implementation of

Alternative 8.

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5.15.3.4 Tax Revenue and Property Values

5.15.3.4.1 No Action Alternative (Future without Project Conditions)

As coastal land loss continues in the future, properties would continue to become more

susceptible to damage by tropical storms and hurricanes. The prospects of income

opportunities may decline in the rural areas if they experience continued depletion of

their natural resources. Residents and businesses may decide to move further inland to

avoid the effects of periodic tropical storms and hurricanes, reducing tax revenues and

property values in areas being vacated.

5.15.3.4.2 Alternative 2 (NER Plan and RP)

5.15.3.4.2.1 Direct

Direct impacts to tax revenue and property values from implementation of Alternative 2

are expected to be minor.

5.15.3.4.2.2 Indirect

To the extent that tax revenues and property values are impacted by coastal land loss,

Alternative 2 would be expected to provide benefits. Reducing the rate of land loss in the

project area would be expected to decrease the rate of businesses and residents leaving

the area to avoid the effects of periodic tropical storms and hurricanes.

5.15.3.4.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater impact on tax revenue and property

values, as those programs would work synergistically to improve habitat conditions

across the area.

5.15.3.4.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree.

5.15.3.4.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree.

5.15.3.4.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater degree.

5.15.3.4.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser degree.

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5.15.3.4.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

Alternative 2, but to a lesser degree.

5.15.3.4.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree.

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5.15.3.5 Community and Regional Growth (including Community Cohesion)

5.15.3.5.1 No Action Alternative (Future without Project Conditions)

As inland marshes and barrier islands erode or subside in the Future Without-Project

conditions the resultant threatened population in the coastal communities is expected to

shift to the more northern portions of the coastal parishes. As these populations get

dispersed and absorbed into other geographic areas, their heritage and cultural way of life

could also be threatened.

Overall, the population of Lafourche, St. Mary, and Terrebonne Parishes increased from

105,953 to 247,685 from 1940 to 2000. This population is expected to increase to

approximately 261,000 by 2030 (Blanchard 2009). It is expected that this growth rate

will occur with or without the project in place. The exact location of the population

growth and shift would be influenced by many factors including land availability, flood

protection, and improvements to the transportation network.

5.15.3.5.2 Alternative 2 (NER Plan and RP)

5.15.3.5.2.1 Direct

No direct impacts to community and regional growth or community cohesion are

anticipated from implementation of Alternative 2.

5.15.3.5.2.2 Indirect

Shifts in coastal population patterns to more northern portions of the parishes, as affected

by deterioration of coastal habitats, could be slower than with the No Action Alternative.

Likewise, as the coastal marsh systems in the project area are a defining characteristic in

local culture and way of life, the reduction in the rate of decline of the resource afforded

by implementation of Alternative 2 would have a positive impact on community

cohesion.

5.15.3.5.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater impact on community and regional

growth and community cohesion, as those programs would work synergistically to

improve habitat conditions across the area.

5.15.3.5.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2, but to a greater degree.

5.15.3.5.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but to a greater degree.

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5.15.3.5.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but to a greater degree.

5.15.3.5.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2, but to a lesser degree.

5.15.3.5.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

Alternative 2, but to a lesser degree.

5.15.3.5.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2, but to a lesser degree.

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5.15.4 Environmental Justice

5.15.4.1 No Action Alternative (Future without Project Conditions)

Minority and/or low-income communities have been identified throughout the study area.

In the future without project conditions, no anticipated disproportionately high or adverse

human health or environmental effects on minority or low-income populations would

occur, as no property would be acquired for construction of the proposed ARTM project

within the study area and no construction activities would occur.

5.15.4.2 Alternative 2 (NER Plan and RP)

5.15.4.2.1 Direct

Minority and/or low-income communities are located throughout the wider study area.

There would be no anticipated disproportionately high or adverse human health or

environmental effects on minority or low-income populations, as no property is expected

to be acquired for construction of the proposed ARTM project within the study area.

West-Bayou Penchant Area

Low-income populations have been identified within the Central-Lake Boudreaux study

area, per 2000 U.S. Census information and requirements of E.O. 12898. This area

should be considered for further public outreach efforts for Environmental Justice.

Impacts from construction activities such as air quality, noise, traffic, safety, etc. would

be temporary in nature (no more than 12-24 months) and would have minimal, if any,

disproportionately high, direct adverse human health or environmental impacts on

minority and/or low income communities.

Central-Lake Boudreaux Area

The direct impacts of the proposed East-Grand Bayou study area to EJ would be similar

to those described for the West-Bayou Penchant Area.

East-Grand Bayou Area

5.15.4.2.2 Indirect

No disproportionately high or adverse human health or environmental indirect impacts on

minority and/or low-income populations would occur.

5.15.4.2.3 Cumulative

There may be synergistic cumulative impacts of implementing the proposed ARTM

project on minority and/or low-income communities within the study area per 2000 U.S.

Census information and requirements of E.O. 12898. These impacts would be the

additive combination of impacts and benefits for overall net acres created, nourished, and

protected by other Federal, state, local and private restoration efforts. The project would

contribute toward achieving and sustaining a coastal ecosystem that can support and

protect the environment, local economy, and culture of the region. Further public

outreach efforts should be made per requirements of E.O. 12898.

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5.15.4.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would be similar to Alternative 2.

5.15.4.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would be similar to Alternative 2

5.15.4.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would be similar to Alternative 2.

5.15.4.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would be similar to Alternative 2.

5.15.4.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would be similar to Alternative 2.

5.15.4.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would be similar to Alternative 2.

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5.15.5 Water Use and Supply

5.15.5.1 No Action Alternative (Future without Project Conditions)

In many coastal areas of southeastern Louisiana, fresh surface water supplies would be

limited to the Mississippi River, Atchafalaya River, and many of their distributaries.

Because many of these water bodies are controlled by levees and flows are maintained, it

is doubtful that they would be affected by loss of surrounding wetlands. Also, because

these water bodies are the major sources of freshwater in southeastern Louisiana, water

use would be largely unaffected. However, Bayou Lafourche currently experiences

periodic saltwater intrusion, primarily from Company Canal and the GIWW. Salinities in

this bayou could increase, limiting freshwater supplies, if the surrounding area became

saltier. The economic effects would be felt by industry, agriculture, and the public

supply in this area. Because fresh groundwater is very limited or unavailable in most of

the Bayou Lafourche area, the larger water users in this area, primarily industry and

public supply, would have to treat (desalinate) the water for salinity or find new sources

of freshwater. This could affect public water supply, agricultural use, and industrial use

in this area, resulting in increased costs for water treatment (desalination). Businesses

could be forced to relocate, thereby potentially adversely affecting jobs, income,

population, and property values.

5.15.5.2 Alternative 2 (NER Plan and RP)

5.15.5.2.1 Direct

Alternative 2 is not anticipated to have any direct impacts to drinking water supply or

agricultural water use.

5.15.5.2.2 Indirect

The additional flow into the Lake Boudreaux and Grand Bayou basins would work to

slow salt water intrusion in these areas. Slowed marsh loss would delay the intrusion of

salt water to populated portions of the project area. Decreased flow through the GIWW

at Larose could increase the intrusion of salt water in Bayou Lafourche. This could result

in the loss of agricultural water use in Bayou Lafourche south of Larose, similar to the

No Action Alternative.

5.15.5.2.3 Cumulative

Other hydrologic changes and marsh restoration efforts by Federal, state, local, and

private projects could enhance the benefits of this alternative. Marsh loss and salt water

intrusion would be slowed. Changing operations of diversions within the Barataria basin

could minimize the impacts to Bayou Lafourche.

5.15.5.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would generally be similar to

Alternative 2.

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5.15.5.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would generally be similar to

Alternative 2, but with larger indirect impacts to water use in Bayou Lafourche and in the

Barataria basin in areas influenced by freshwater from the GIWW.

5.15.5.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would generally be similar to

Alternative 2, but with larger indirect impacts to water use in Bayou Lafourche and in the

Barataria basin in areas influenced by freshwater from the GIWW.

5.15.5.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would generally be similar to

Alternative 2.

5.15.5.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would generally be similar to

the No Action Alternative.

5.15.5.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would generally be similar to

Alternative 2.

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5.15.6 Navigation

5.15.6.1 No Action Alternative (Future without Project Conditions)

A majority of Louisiana’s navigable waterways would be adversely impacted without

action as marshes and barrier islands that protect waterborne traffic on inland waterways

continue to erode. As land adjacent to and connecting these waterways disappears,

waterways currently protected would be exposed to wind, weather, and waves found in

open bays and the Gulf of Mexico. Additionally, navigation channels that cross open

bays may silt in more rapidly or begin to shoal in less predictable ways. The potential

impacts to these waterways and the vessels that use them include increased maintenance

costs (e.g., dredging), the necessity for higher horsepower vessels to counteract increased

currents and wave forces, and increased risk of groundings, collisions or storm damage to

vessels and cargo. Moreover, shoaling causes the thousands of tows that traverse this

area annually to slow down, thereby increasing both the transit time and cost of

transportation. Due to increased safety concerns, alternate methods of transportation may

have to be taken by hazardous commodities now utilizing the GIWW. These impacts

would have a corresponding effect on cargo rates, which would affect the local and

national economies.

The growth rate estimate for the Louisiana portion of the GIWW is 0.78 percent annually

(this is the midlevel estimate from a commodity forecast from the Calcasieu Lock

Replacement Study). Average annual growth for activity associated with rig fabrication

and the offshore service industry is 1.67 percent (this estimate comes from a forecast

prepared for the Houma Navigation Canal Deepening Study). Any environmentally

negative impacts to navigation in the study area would worsen over time with the No

Action Alternative.

5.15.6.2 Alternative 2 (NER Plan and RP)

5.15.6.2.1 Direct

With implementation of Alternative 2, navigation on the Houma Navigation Canal would

be impacted. The flood gate on the HNC would be closed most of the time with

implementation of Alternative 2, requiring vessels needing passage to use the adjacent

lock. Use of the lock would increase transportation costs for upbound and downbound

traffic on the HNC by increasing transportation time and associated operational costs.

According to navigation modeling conducted for the Morganza to the Gulf Study, vessels

required to use the lock due to flood gate closure would incur an 18-minute process time

moving through the lock. According to 2007 annual usage statistics

(www.iwr.usace.army.mil/ndc/wcsc/wcsc.htm; accessed 11 December 2009), the HNC

was utilized by 9,338 vessels to transport 844,305 tons of cargo. Implementation of

Alternative 2, increasing annual closure duration of the flood gates from two months (No

Action Alternative) to twelve months, would therefore delay 10 months of HNC traffic,

or 7,782 vessels. Utilizing costs from the Morganza to the Gulf navigation study,

adjusted for inflation, delaying 7,782 vessels for 18 minutes translates to $240,600 in

increased operating costs per year. Operation and maintenance costs associated with the

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lock complex would also increase; however, these costs have not yet been determined

under the Morganza to the Gulf Project.

Navigation of commercial and recreational vessels on other water bodies would also be

impacted by features of Alternative 2 (see Figure 5.1 for general feature locations and

Figures 5.34 through 5.36 for specific locations). Feature WP1 would block access to a

small area of saline marsh near Lake Mechant. The extent of current use of this area is

unknown. The weir at Grand Pass (WW2) would restrict movement of vessels with a

draft greater than 12 feet or a width greater than 100 feet. Vessel data is not available for

this area; however, the proposed structure size is expected to accommodate current vessel

usage. The plug in Robinson Canal (CP1) would prevent vessel movement between Lake

Boudreaux and Bayou Petit Caillou, limiting ingress and egress from the east to

Boudreaux Canal; however, vessel movement through Robinson canal is already

extremely limited due to the Highway 57 bridge. Feature CP2 would block a small canal

near Lake Boudreaux; however the canal is currently largely blocked by the remnants of

a plug. Feature CC15 would restrict movement in a canal near Lake Boudreaux, but is

expected to accommodate current vessel sizes. The weir in Cutoff Canal (EP7) would

restrict movement of vessels with a draft greater than 5 feet or a width greater than 20

feet. This should accommodate most current vessel sizes. Alternate routes of

ingress/egress exist to the east.

5.15.6.2.2 Indirect

Reducing the rate of land loss in the project area would be expected to provide indirect

benefits to navigation by decreasing the exposure of navigable waterways to wind and

waves, thereby reducing impacts associated with groundings, collisions, storm damage,

and associated increases in transportation costs.

Secondary erosion along channels receiving increased flows may occur with

implementation of Alternative 2, resulting in localized increases in sedimentation and

shoaling in area waterways.

5.15.6.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater indirect impact on navigation, as those

programs would work synergistically to improve habitat conditions across the area.

Negative impacts to navigation are not anticipated to have any greater impact when

considered cumulatively with other Federal, state, local, or private impacts to navigation

in the area.

5.15.6.3 Alternative 3

5.15.6.3.1 Direct

Direct impacts of Alternative 3 on navigation would be similar to those of Alternative 2.

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5.15.6.3.2 Indirect

Indirect impacts of Alternative 3 on navigation would be similar to those of Alternative 2,

but to a lesser degree.

5.15.6.3.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 3 would have an even greater indirect impact on navigation, as those

programs would work synergistically to improve habitat conditions across the area.

Negative impacts to navigation are not anticipated to have any greater impact when

considered cumulatively with other Federal, state, local, or private impacts to navigation

in the area.

5.15.6.4 Alternative 4

5.15.6.4.1 Direct

Direct impacts of Alternative 4 on navigation would be similar to those of Alternative 2,

with the additional impact of the plug in Bayou L’eau Blue (EP8). This feature would

block vessel movement between the GIWW and Grand Bayou. However, vessel

movement is currently limited to small vessels due to the Highway 24 bridge.

5.15.6.4.2 Indirect

Indirect impacts of Alternative 4 on navigation would be similar to those of Alternative 2,

but to a greater degree.

5.15.6.4.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 4 would have an even greater indirect impact on navigation, as those

programs would work synergistically to improve habitat conditions across the area.

Negative impacts to navigation are not anticipated to have any greater impact when

considered cumulatively with other Federal, state, local, or private impacts to navigation

in the area.

5.15.6.5 Alternative 5

5.15.6.5.1 Direct

Direct impacts of Alternative 5 on navigation would be similar to those of Alternative 2,

with the additional impact of the plug in Bayou L’eau Blue (EP8). This feature would

block vessel movement between the GIWW and Grand Bayou. However, vessel

movement is currently limited to small vessels due to the Highway 24 bridge.

5.15.6.5.2 Indirect

Indirect impacts of Alternative 5 on navigation would be similar to those of Alternative 2,

but to a greater degree.

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5.15.6.5.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 5 would have an even greater indirect impact on navigation, as those

programs would work synergistically to improve habitat conditions across the area.

Negative impacts to navigation are not anticipated to have any greater impact when

considered cumulatively with other Federal, state, local, or private impacts to navigation

in the area.

5.15.6.6 Alternative 6

5.15.6.6.1 Direct

Direct impacts of Alternative 6 on navigation would be similar to those of Alternative 2,

but would be limited to the impacts associated with the modified operation of the HNC

lock complex.

5.15.6.6.2 Indirect

Indirect impacts of Alternative 6 on navigation would be similar to those of Alternative 2,

but to a lesser degree.

5.15.6.6.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 6 would have an even greater indirect impact on navigation, as those

programs would work synergistically to improve habitat conditions across the area.

Negative impacts to navigation are not anticipated to have any greater impact when

considered cumulatively with other Federal, state, local, or private impacts to navigation

in the area.

5.15.6.7 Alternative 7

5.15.6.7.1 Direct

Direct impacts of Alternative 7 on navigation would be similar to those of Alternative 2,

but would be limited to the impacts associated with the modified operation of the HNC

lock complex.

5.15.6.7.2 Indirect

Indirect impacts of Alternative 7 on navigation would be similar to those of Alternative 2,

but to a lesser degree.

5.15.6.7.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 7 would have an even greater indirect impact on navigation, as those

programs would work synergistically to improve habitat conditions across the area.

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Negative impacts to navigation are not anticipated to have any greater impact when

considered cumulatively with other Federal, state, local, or private impacts to navigation

in the area.

5.15.6.8 Alternative 8

5.15.6.8.1 Direct

Direct impacts of Alternative 8 on navigation would be similar to those of Alternative 2,

with the exception of features WP1 and WW2 which would not be implemented under

Alternative 8.

5.15.6.8.2 Indirect

Indirect impacts of Alternative 8 on navigation would be similar to those of Alternative 2,

but to a lesser degree.

5.15.6.8.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 8 would have an even greater indirect impact on navigation, as those

programs would work synergistically to improve habitat conditions across the area.

Negative impacts to navigation are not anticipated to have any greater impact when

considered cumulatively with other Federal, state, local, or private impacts to navigation

in the area.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.34. Locations of Features with Potential Navigation Impacts in the Western Region of the Study Area.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.35. Locations of Features with Potential Navigation Impacts in the Central Region of the Study Area.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Figure 5.36. Locations of Features with Potential Navigation Impacts in the Eastern Region of the Study Area.

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5.15.7 Land Use and Socioeconomics

5.15.7.1 Agriculture

5.15.7.1.1 No Action Alternative (Future without Project Conditions)

With the implementation of the No Action Alternative, land loss in the project area would

continue. Levees protecting agricultural lands situated along the distributary ridges in the

project area would become increasingly vulnerable to storm damage as marshes that

buffer wave impacts degrade.

5.15.7.1.2 Alternative 2 (NER Plan and RP)

5.15.7.1.2.1 Direct

No direct impacts to Agriculture are anticipated from implementation of Alternative 2.

5.15.7.1.2.2 Indirect

Reducing the rate of land loss in the project area would be expected to provide indirect

benefits to agriculture by decreasing the exposure of levees to wave damage.

5.15.7.1.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater indirect impact on agriculture, as those

programs would work synergistically to improve habitat conditions across the area.

5.15.7.1.3 Alternative 3

5.15.7.1.3.1 Direct

No direct impacts to Agriculture are anticipated from implementation of Alternative 3.

5.15.7.1.3.2 Indirect

Indirect impacts of Alternative 3 on Agriculture would be similar to those of Alternative

2, but to a greater degree.

5.15.7.1.3.3 Cumulative

Cumulative impacts of Alternative 3 on Agriculture would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.1.4 Alternative 4

5.15.7.1.4.1 Direct

No direct impacts to Agriculture are anticipated from implementation of Alternative 4.

5.15.7.1.4.1 Indirect

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Indirect impacts of Alternative 4 on Agriculture would be similar to those of Alternative

2, but to a greater degree.

5.15.7.1.4.2 Cumulative

Cumulative impacts of Alternative 4 on Agriculture would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.1.5 Alternative 5

5.15.7.1.5.1 Direct

No direct impacts to Agriculture are anticipated from implementation of Alternative 5.

5.15.7.1.5.2 Indirect

Indirect impacts of Alternative 5 on Agriculture would be similar to those of Alternative

2, but to a greater degree.

5.15.7.1.5.3 Cumulative

Cumulative impacts of Alternative 5 on Agriculture would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.1.6 Alternative 6

5.15.7.1.6.1 Direct

No direct impacts to Agriculture are anticipated from implementation of Alternative 6.

5.15.7.1.6.2 Indirect

Indirect impacts of Alternative 6 on Agriculture would be similar to those of Alternative

2, but to a lesser degree.

5.15.7.1.6.3 Cumulative

Cumulative impacts of Alternative 6 on Agriculture would be similar to those of

Alternative 2, but to a lesser degree.

5.15.7.1.7 Alternative 7

5.15.7.1.7.1 Direct

No direct impacts to Agriculture are anticipated from implementation of Alternative 7.

5.15.7.1.7.2 Indirect

Indirect impacts of Alternative 7 on Agriculture would be similar to those of Alternative

2, but to a lesser degree.

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5.15.7.1.7.3.1 Cumulative

Cumulative impacts of Alternative 7 on Agriculture would be similar to those of

Alternative 2, but to a lesser degree.

5.15.7.1.8 Alternative 8

5.15.7.1.8.1 Direct

No direct impacts to Agriculture are anticipated from implementation of Alternative 8.

5.15.7.1.8.2 Indirect

Indirect impacts of Alternative 8 on Agriculture would be similar to those of Alternative

2, but to a lesser degree.

5.15.7.1.8.3 Cumulative

Cumulative impacts of Alternative 8 on Agriculture would be similar to those of

Alternative 2, but to a lesser degree.

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5.15.7.2 Forestry

5.15.7.2.1 No Action Alternative (Future without Project Conditions)

With the implementation of the No Action Alternative, land loss in the project area would

continue. Levees protecting agricultural lands used for timber production situated along

the distributary ridges in the project area would become increasingly vulnerable to storm

damage as marshes that buffer wave impacts degrade.

5.15.7.2.2 Alternative 2 (NER Plan and RP)

5.15.7.2.2.1 Direct

No direct impacts to forestry resources are anticipated from implementation of

Alternative 2.

5.15.7.2.2.2 Indirect

Reducing the rate of land loss in the project area would be expected to provide indirect

benefits to agricultural lands used for timber production by decreasing the exposure of

levees to wave damage.

5.15.7.2.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater indirect impact on forestry resources, as

those programs would work synergistically to improve habitat conditions across the area.

5.15.7.2.3 Alternative 3

5.15.7.2.3.1 Direct

No direct impacts to forestry resources are anticipated from implementation of

Alternative 3.

5.15.7.2.3.2 Indirect

Indirect impacts of Alternative 3 on forestry resources would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.2.3.3 Cumulative

Cumulative impacts of Alternative 3 on forestry resources would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.2.4 Alternative 4

5.15.7.2.4.1 Direct

No direct impacts to forestry resources are anticipated from implementation of

Alternative 4.

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5.15.7.2.4.2 Indirect

Indirect impacts of Alternative 4 on forestry resources would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.2.4.3 Cumulative

Cumulative impacts of Alternative 4 on forestry resources would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.2.5 Alternative 5

5.15.7.2.5.1 Direct

No direct impacts to forestry resources are anticipated from implementation of

Alternative 5.

5.15.7.2.5.2 Indirect

Indirect impacts of Alternative 5 on forestry resources would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.2.5.3 Cumulative

Cumulative impacts of Alternative 5 on forestry resources would be similar to those of

Alternative 2, but to a greater degree.

5.15.7.2.6 Alternative 6

5.15.7.2.6.1 Direct

No direct impacts to forestry resources are anticipated from implementation of

Alternative 6.

5.15.7.2.6.2 Indirect

Indirect impacts of Alternative 6 on forestry resources would be similar to those of

Alternative 2, but to a lesser degree.

5.15.7.2.6.3 Cumulative

Cumulative impacts of Alternative 6 on forestry resources would be similar to those of

Alternative 2, but to a lesser degree.

5.15.7.2.7 Alternative 7

5.15.7.2.7.1 Direct

No direct impacts to forestry resources are anticipated from implementation of

Alternative 7.

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5.15.7.2.7.2 Indirect

Indirect impacts of Alternative 7 on forestry resources would be similar to those of

Alternative 2, but to a lesser degree.

5.15.7.2.7.3 Cumulative

Cumulative impacts of Alternative 7 on forestry resources would be similar to those of

Alternative 2, but to a lesser degree.

5.15.7.2.8 Alternative 8

5.15.7.2.8.1 Direct

No direct impacts to forestry resources are anticipated from implementation of

Alternative 8.

5.15.7.2.8.2 Indirect

Indirect impacts of Alternative 8 on forestry resources would be similar to those of

Alternative 2, but to a lesser degree.

5.15.7.2.8.3 Cumulative

Cumulative impacts of Alternative 8 on forestry resources would be similar to those of

Alternative 2, but to a lesser degree.

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5.15.8 Public Lands

5.15.8.1 No Action Alternative (Future without Project Conditions)

With implementation of the No Action Alternative, current land loss rates in and around

the Mandalay National Wildlife Refuge and the Pointe Au Chien Wildlife Management

Area would be expected to continue. The majority of Mandalay National Wildlife

Refuge is located in areas that are showing a slight increase in land area. Pointe Au

Chien Wildlife Management Area is located in areas that are showing loss rates of

between 0.33 and 1.16 percent per year.

5.15.8.2 Alternative 2 (NER Plan and RP)

5.15.8.2.1 Direct

No direct impacts to Mandalay National Wildlife Refuge are anticipated from

implementation of Alternative 2. Features ED2, ED7, ED6, EM1, EX1, EX2, EC3, EG1,

and EG2 are located within the boundaries of the Pointe Au Chien Wildlife Management

Area. Features EC7, EC6, EC2, ED3, ED5, EC5, and EP7 are located outside the

boundaries of the management area but would directly impact it. These features would

change water flows into and out of the management area, thereby changing salinity levels

(see Figure 5.10). Areas west of Grand Bayou are projected to see slight increases in

average annual salinity values of 0.3 to 0.4 ppt. Areas to the east of Grand Bayou are

projected to see decreases in average annual salinity values of between 1.7 and 2.0 ppt.

5.15.8.2.2 Indirect

Changes in water flows and resultant changes in salinities and nutrient concentrations are

expected to benefit the Pointe Au Chien Wildlife Management Area. Polygons in the

area are projected to yield 973 AAHUs over the 50-year period of analysis as a result of

implementation of Alternative 2 (see Figure 5.2). No change in AAHUs as compared to

the No Action Alternative is anticipated for the Mandalay National Wildlife Refuge.

5.15.8.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater indirect impact on public lands, as those

programs would work synergistically to improve habitat conditions across the area.

5.15.8.3 Alternative 3

5.15.8.3.1 Direct

No direct impacts to Mandalay National Wildlife Refuge are anticipated from

implementation of Alternative 3. Features ED2, ED7, ED6, EM1, EX1, EX2, EC3, EG1,

and EG2 are located within the boundaries of the Pointe Au Chien Wildlife Management

Area. Features EC7, EC6, EC2, ED3, ED5, EC5, and EP7 are located outside the

boundaries of the management area but would directly impact it. These features would

change water flows into and out of the management area, thereby changing salinity levels

(see Figure 5.11). Areas west of Grand Bayou are projected to see slight increases in

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average annual salinity values of 0.3 ppt. Areas to the east of Grand Bayou are projected

to see decreases in average annual salinity values of between 1.7 and 2.2 ppt.

5.15.8.3.2 Indirect

Changes in water flows and resultant changes in salinities and nutrient concentrations are

expected to benefit the Pointe Au Chien Wildlife Management Area. Polygons in the

area are projected to yield 987 AAHUs over the 50-year period of analysis as a result of

implementation of Alternative 3 (see Figure 5.3). No change in AAHUs as compared to

the No Action Alternative is anticipated for the Mandalay National Wildlife Refuge.

5.15.8.3.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 3 would have an even greater indirect impact on public lands, as those

programs would work synergistically to improve habitat conditions across the area.

5.15.8.4 Alternative 4

5.15.8.4.1 Direct

No direct impacts to Mandalay National Wildlife Refuge are anticipated from

implementation of Alternative 4. Features ED2, ED7, ED6, EM1, EX1, EX2, EC3, EG1,

and EG2 are located within the boundaries of the Pointe Au Chien Wildlife Management

Area. Features EC7, EC6, EC2, ED3, ED5, ES2, EP7, and EP8 are located outside the

boundaries of the management area but would directly impact it. These features would

change water flows into and out of the management area, thereby changing salinity levels

(see Figure 5.12). Areas west of Grand Bayou are projected to see slight decreases in

average annual salinity values ranging from 1.3 to 1.8 ppt. Areas to the east of Grand

Bayou are projected to see large decreases in average annual salinity values of between

6.6 and 7.2 ppt.

5.15.8.4.2 Indirect

Changes in water flows and resultant changes in salinities and nutrient concentrations are

expected to benefit the Pointe Au Chien Wildlife Management Area. Polygons in the

area are projected to yield 2,234 AAHUs over the 50-year period of analysis as a result of

implementation of Alternative 4 (see Figure 5.4). No change in AAHUs as compared to

the No Action Alternative is anticipated for the Mandalay National Wildlife Refuge.

5.15.8.4.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 4 would have an even greater indirect impact on public lands, as those

programs would work synergistically to improve habitat conditions across the area.

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5.15.8.5 Alternative 5

5.15.8.5.1 Direct

No direct impacts to Mandalay National Wildlife Refuge are anticipated from

implementation of Alternative 5. Features ED2, ED7, ED6, EM1, EX1, EX2, EC3, EG1,

and EG2 are located within the boundaries of the Pointe Au Chien Wildlife Management

Area. Features EC7, EC6, EC2, ED3, ED5, ES2, EP7, and EP8 are located outside the

boundaries of the management area but would directly impact it. These features would

change water flows into and out of the management area, thereby changing salinity levels

(see Figure 5.13). Areas west of Grand Bayou are projected to see slight decreases in

average annual salinity values ranging from 1.3 to 1.9 ppt. Areas to the east of Grand

Bayou are projected to see large decreases in average annual salinity values of between

6.6 and 7.2 ppt.

5.15.8.5.2 Indirect

Changes in water flows and resultant changes in salinities and nutrient concentrations are

expected to benefit the Pointe Au Chien Wildlife Management Area. Polygons in the

area are projected to yield 2,235 AAHUs over the 50-year period of analysis as a result of

implementation of Alternative 5 (see Figure 5.5). No change in AAHUs as compared to

the No Action Alternative is anticipated for the Mandalay National Wildlife Refuge.

5.15.8.5.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 5 would have an even greater indirect impact on public lands, as those

programs would work synergistically to improve habitat conditions across the area.

5.15.8.6 Alternative 6

5.15.8.6.1 Direct

No direct impacts to Mandalay National Wildlife Refuge are anticipated from

implementation of Alternative 6. Features ED3, ED5, and EC5 are located outside the

boundaries of the Pointe Au Chien Wildlife Management Area but would directly impact

it. These features would change water flows into and out of the management area,

thereby changing salinity levels (see Figure 5.14). Areas west of Grand Bayou are

projected to see slight decreases in average annual salinity values of 0.3 to 0.7 ppt. Areas

to the east of Grand Bayou are projected to see decreases in average annual salinity

values of between 1.5 and 1.7 ppt.

5.15.8.6.2 Indirect

Changes in water flows and resultant changes in salinities and nutrient concentrations are

expected to benefit the Pointe Au Chien Wildlife Management Area. Polygons in the

area are projected to yield 611 AAHUs over the 50-year period of analysis as a result of

implementation of Alternative 6 (see Figure 5.6). No change in AAHUs as compared to

the No Action Alternative is anticipated for the Mandalay National Wildlife Refuge.

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5.15.8.6.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 6 would have an even greater indirect impact on public lands, as those

programs would work synergistically to improve habitat conditions across the area.

5.15.8.7 Alternative 7

5.15.8.7.1 Direct

No direct impacts to Mandalay National Wildlife Refuge are anticipated from

implementation of Alternative 7. Modified operation of the HNC lock complex is

expected to change flows in the Grand Bayou basin, thereby changing salinity levels (see

Figure 5.15). Areas west of Grand Bayou are projected to see slight decreases in average

annual salinity values of 0.1 ppt. Areas to the east of Grand Bayou are projected to see

decreases in average annual salinity values of between 0.3 and 0.4 ppt.

5.15.8.7.2 Indirect

Changes in water flows and resultant changes in salinities and nutrient concentrations are

expected to impact the Pointe Au Chien Wildlife Management Area. Polygons in the

area are projected to yield a net loss of 41 AAHUs over the 50-year period of analysis as

a result of implementation of Alternative 7 (see Figure 5.7). No change in AAHUs as

compared to the No Action Alternative is anticipated for the Mandalay National Wildlife

Refuge.

5.15.8.7.3 Cumulative

Negative impacts to public lands from implementation of Alternative 7 are not

anticipated to have any greater impact when considered cumulatively with other Federal,

state, local, or private impacts to public lands in the area.

5.15.8.8 Alternative 8

5.15.8.8.1 Direct

No direct impacts to Mandalay National Wildlife Refuge are anticipated from

implementation of Alternative 8. Features ED6, EX1, EX2, EC3, EG1, and EG2 are

located within the boundaries of the Pointe Au Chien Wildlife Management Area.

Features EC2, ED3, ED5, EC5, and EP7 are located outside the boundaries of the

management area but would directly impact it. These features would change water flows

into and out of the management area, thereby changing salinity levels (see Figure 5.16).

Areas west of Grand Bayou are projected to see slight decreases in average annual

salinity values of 0.1 to 0.6 ppt. Areas to the east of Grand Bayou are projected to see

decreases in average annual salinity values of between 1.5 and 2.2 ppt.

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5.15.8.8.2 Indirect

Changes in water flows and resultant changes in salinities and nutrient concentrations are

expected to benefit the Pointe Au Chien Wildlife Management Area. Polygons in the

area are projected to yield 938 AAHUs over the 50-year period of analysis as a result of

implementation of Alternative 8 (see Figure 5.8). No change in AAHUs as compared to

the No Action Alternative is anticipated for the Mandalay National Wildlife Refuge.

5.15.8.8.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 8 would have an even greater indirect impact on public lands, as those

programs would work synergistically to improve habitat conditions across the area.

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5.15.9 Man Made Resources

5.15.9.1 Oil , Gas, and Utilities

The impacts of the Deepwater Horizon oil spill on coastal Louisiana are uncertain at this

time (August 2010). The impacts of the oil spill as well as the various emergency actions

taken to address oil spill impacts (e.g., use of oil dispersants, creation of sand berms, use

of Hesco baskets, rip-rap, sheet piling and other actions) could potentially impact

USACE water resources projects and studies within the Louisiana coastal area, including

the LCA-ARTM project. Potential impacts could include factors such as changes to

existing, future-without, and future-with-project conditions, as well as increased project

costs and implementation delays. The USACE will continue to monitor and closely

coordinate with other Federal and state resource agencies and local sponsors in

determining how to best address any potential problems associated with the oil spill that

may adversely impact project implementation. Supplemental planning and

environmental documentation may be required as information becomes available. If at

any time petroleum or crude oil is discovered on project lands, all efforts will be taken to

seek clean up by the responsible parties, pursuant to the Oil Pollution Act of 1990 (33

U.S.C. 2701 et seq.).

5.15.9.1.1 No Action Alternative (Future without Project Conditions)

Most of Louisiana’s onshore oil and gas production occurs in the Louisiana coastal

ecosystem. This area is at an elevated risk due to the land loss and ecosystem

degradation. Loss of wetland, marsh, and barrier islands presents a range of threats to

inshore and offshore oil and gas infrastructure. Existing inshore facilities are not

designed to withstand excessive wind and wave actions, which would become more

commonplace as existing marshes are lost or converted into open bays. In addition,

erosion and the subsequent disappearance of barrier islands would allow gulf type swells

from tropical storm events to travel farther inland. The combination of these factors

would increase the risk to inshore facilities. To address this risk, the oil and gas industry

will be faced with the decision to invest in improvements in order to maintain

production/transmission or conversely the closure and abandonment of infrastructure.

The offshore oil and gas industry in the coastal zone is an important component in

meeting national energy requirements. Coastal land losses have, and will continue to

have, a negative effect on the extensive pipeline network located in coastal areas. As the

open water areas behind the barrier islands increase in size, the tidal exchange volumes

and velocities increase in the tidal passes and channels. This action can lead to the

scouring away of sediments atop buried pipelines, exposing the pipelines and increasing

the risk of failure or damage due to lack of structural stability, anchor dragging, and boat

collisions. Resulting production or transmission shortfalls may result in disruptions in

the availability of crude oil or natural gas to a significant part of the U.S. Oil and gas

infrastructure in the project area can be seen in Figure 4.10.

The impact to these nationally important resources would be felt in numerous ways

depending upon location (i.e., whether onshore or offshore).

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5.15.9.1.2 Alternative 2 (NER Plan and RP)

5.15.9.1.2.1 Direct

No direct impacts to oil and gas infrastructure are anticipated from implementation of

Alternative 2. Construction of features CC3, CC4, CD1, CD4, CD6, CD7, CLV2, CM4,

and ED5 may require relocation of existing utility lines.

5.15.9.1.2.2 Indirect

Implementation of Alternative 2 and the associated reduction in the rate of land loss in

the project area would be expected to provide indirect benefits to oil, gas, and utility

infrastructure by decreasing erosion and associated structural instability of infrastructure,

thereby reducing the likelihood of damage and interruption of service.

5.15.9.1.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater indirect impact on oil, gas, and utilities,

as those programs would work synergistically to improve habitat conditions across the

area.

5.15.9.1.3 Alternative 3

5.15.9.1.3.1 Direct

No direct impacts to oil and gas infrastructure are anticipated from implementation of

Alternative 3. Construction of features CC3, CC4, CD1, CD4, CD6, CD7, CLV2, CM4,

and ED5 may require relocation of existing utility lines.

5.15.9.1.3.2 Indirect

Implementation of Alternative 3 and the associated reduction in the rate of land loss in

the project area would be expected to provide indirect benefits to oil, gas, and utility

infrastructure by decreasing erosion and associated structural instability of infrastructure,

thereby reducing the likelihood of damage and interruption of service.

5.15.9.1.3.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 3 would have an even greater indirect impact on oil, gas, and utilities,

as those programs would work synergistically to improve habitat conditions across the

area.

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5.15.9.1.4 Alternative 4

5.15.9.1.4.1 Direct

No direct impacts to oil and gas infrastructure are anticipated from implementation of

Alternative 4. Construction of features CC3, CC4, CD1, CD4, CD6, CD7, CLV2, CM4,

and ED5 may require relocation of existing utility lines.

5.15.9.1.4.2 Indirect

Implementation of Alternative 4 and the associated reduction in the rate of land loss in

the project area would be expected to provide indirect benefits to oil, gas, and utility

infrastructure by decreasing erosion and associated structural instability of infrastructure,

thereby reducing the likelihood of damage and interruption of service.

5.15.9.1.4.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 4 would have an even greater indirect impact on oil, gas, and utilities,

as those programs would work synergistically to improve habitat conditions across the

area.

5.15.9.1.5 Alternative 5

5.15.9.1.5.1 Direct

No direct impacts to oil and gas infrastructure are anticipated from implementation of

Alternative 5. Construction of features CC3, CC4, CD1, CD4, CD6, CD7, CLV2, CM4,

and ED5 may require relocation of existing utility lines.

5.15.9.1.5.2 Indirect

Implementation of Alternative 5 and the associated reduction in the rate of land loss in

the project area would be expected to provide indirect benefits to oil, gas, and utility

infrastructure by decreasing erosion and associated structural instability of infrastructure,

thereby reducing the likelihood of damage and interruption of service.

5.15.9.1.5.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 5 would have an even greater indirect impact on oil, gas, and utilities,

as those programs would work synergistically to improve habitat conditions across the

area.

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5.15.9.1.6 Alternative 6

5.15.9.1.6.1 Direct

No direct impacts to oil and gas infrastructure are anticipated from implementation of

Alternative 6. Construction of features CD4 and ED5 may require relocation of existing

utility lines.

5.15.9.1.6.2 Indirect

Implementation of Alternative 6 and the associated reduction in the rate of land loss in

the project area would be expected to provide indirect benefits to oil, gas, and utility

infrastructure by decreasing erosion and associated structural instability of infrastructure,

thereby reducing the likelihood of damage and interruption of service.

5.15.9.1.6.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 6 would have an even greater indirect impact on oil, gas, and utilities,

as those programs would work synergistically to improve habitat conditions across the area.

5.15.9.1.7 Alternative 7

5.15.9.1.7.1 Direct

No direct impacts to oil, gas, or utility infrastructure are anticipated from implementation

of Alternative 7.

5.15.9.1.7.2 Indirect

Implementation of Alternative 7 and the associated reduction in the rate of land loss in

the project area would be expected to provide indirect benefits to oil, gas, and utility

infrastructure by decreasing erosion and associated structural instability of infrastructure,

thereby reducing the likelihood of damage and interruption of service.

5.15.9.1.7.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 7 would have an even greater indirect impact on oil, gas, and utilities,

as those programs would work synergistically to improve habitat conditions across the area.

5.15.9.1.8 Alternative 8

5.15.9.1.8.1 Direct

No direct impacts to oil and gas infrastructure are anticipated from implementation of

Alternative 8. Construction of features CC3, CD1, CD6, CD7, CLV2, and ED5 may

require relocation of existing utility lines.

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5.15.9.1.8.2 Indirect

Implementation of Alternative 8 and the associated reduction in the rate of land loss in

the project area would be expected to provide indirect benefits to oil, gas, and utility

infrastructure by decreasing erosion and associated structural instability of infrastructure,

thereby reducing the likelihood of damage and interruption of service.

5.15.9.1.8.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 8 would have an even greater indirect impact on oil, gas, and utilities,

as those programs would work synergistically to improve habitat conditions across the

area.

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5.15.9.2 Flood Control and Hurricane Protection

5.15.9.2.1 No Action Alternative (Future without Project Conditions)

The continuing erosion of the Louisiana coastline has increased the potential for flood

damages from the surges of hurricanes and tropical storms throughout southern

Louisiana. Failure to maintain coastal wetlands would result in a significant level of

increases in damages from storm surges that are currently reduced by coastal wetlands.

There would also be damages to the levees themselves, which would require increased

expenditures to raise, repair, and replace.

The Morganza to the Gulf of Mexico Risk Reduction Project was considered a likely

future condition for purposes of the ARTM Feasibility Study. The proposed alignment of

the project can be found in Figure 4.11. Existing federal and local levee projects in the

vicinity of the project area can also be found in Figure 4.11.

5.15.9.2.2 Alternative 2 (NER Plan and RP)

5.15.9.2.2.1 Direct

Modifying the operation of the proposed HNC lock complex would have an impact on

water levels in the project area, but would not impact the flood control and hurricane

protection capacity of the proposed system (see Section 5.2.1 and Engineering Appendix

for information on changes in water levels associated with project implementation).

Likewise, project features that lie within the proposed alignment of the Morganza to the

Gulf of Mexico Risk Reduction Project may require modifications to the design of the

levees, but would not impact the flood control and hurricane protection capacity of the

proposed system.

Implementation of Alternative 2 would also result in the raising of the planned elevation

of features CLV1 and CLV2 to accommodate potential increases in water levels due to

project features in the area. CLV1 and CLV2 are levees currently under design by

Terrebonne Parish and are planned for future construction outside of the authority of the

ARTM project.

5.15.9.2.2.2 Indirect

Implementation of Alternative 2 and the associated benefits to marshes in the project area

would be expected to provide indirect benefits to flood control and hurricane protection

levees by helping to retain the wave and storm surge buffering capacity of the marshes,

thereby decreasing storm surge and reducing wave damage.

5.15.9.2.2.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 2 would have an even greater indirect impact on flood control and

hurricane protection, as those programs would work synergistically to improve habitat

conditions across the area.

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5.15.9.2.3 Alternative 3

5.15.9.2.3.1 Direct

Modifying the operation of the proposed HNC lock complex would have an impact on

water levels in the project area, but would not impact the flood control and hurricane

protection capacity of the proposed system (see Section 5.2.1 and Engineering Appendix

for information on changes in water levels associated with project implementation).

Likewise, project features that lie within the proposed alignment of the Morganza to the

Gulf of Mexico Risk Reduction Project may require modifications to the design of the

levees, but would not impact the flood control and hurricane protection capacity of the

proposed system.

Implementation of Alternative 3 would also result in breaching the Avoca Island Levee at

feature WS4. The Avoca Island Levee is part of the East Atchafalaya Basin Protection

Levee (EABPL) and provides the Morgan City area with protection from Atchafalaya

River backwater flooding. Feature WS4 would only be operated at low to moderate

Atchafalaya River stages, and, therefore, would not increase flood heights (see Section

5.2.1 and Engineering Appendix for information on changes in water levels associated

with project implementation).

Alternative 3 would also result in the raising of the planned elevation of features CLV1

and CLV2 to accommodate potential increases in water levels due to project features in

the area. CLV1 and CLV2 are levees currently under design by Terrebonne Parish and

are planned for future construction outside of the authority of the ARTM project.

5.15.9.2.3.2 Indirect

Implementation of Alternative 3 and the associated benefits to marshes in the project area

would be expected to provide indirect benefits to flood control and hurricane protection

levees by helping to retain the wave and storm surge buffering capacity of the marshes,

thereby decreasing storm surge and reducing wave damage.

5.15.9.2.3.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 3 would have an even greater indirect impact on flood control and

hurricane protection, as those programs would work synergistically to improve habitat

conditions across the area.

5.15.9.2.4 Alternative 4

5.15.9.2.4.1 Direct

Modifying the operation of the proposed HNC lock complex would have an impact on

water levels in the project area, but would not impact the flood control and hurricane

protection capacity of the proposed system (see Section 5.2.1 and Engineering Appendix

for information on changes in water levels associated with project implementation).

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Likewise, project features that lie within the proposed alignment of the Morganza to the

Gulf of Mexico Risk Reduction Project may require modifications to the design of the

levees, but would not impact the flood control and hurricane protection capacity of the

proposed system.

Implementation of Alternative 4 would also result in the raising of the planned elevation

of features CLV1 and CLV2 to accommodate potential increases in water levels due to

project features in the area. CLV1 and CLV2 are levees currently under design by

Terrebonne Parish and are planned for future construction outside of the authority of the

ARTM project.

5.15.9.2.4.2 Indirect

Implementation of Alternative 4 and the associated benefits to marshes in the project area

would be expected to provide indirect benefits to flood control and hurricane protection

levees by helping to retain the wave and storm surge buffering capacity of the marshes,

thereby decreasing storm surge and reducing wave damage.

5.15.9.2.4.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 4 would have an even greater indirect impact on flood control and

hurricane protection, as those programs would work synergistically to improve habitat

conditions across the area.

5.15.9.2.5 Alternative 5

5.15.14.2.5.1 Direct

Modifying the operation of the proposed HNC lock complex would have an impact on

water levels in the project area, but would not impact the flood control and hurricane

protection capacity of the proposed system (see Section 5.2.1 and Engineering Appendix

for information on changes in water levels associated with project implementation).

Likewise, project features that lie within the proposed alignment of the Morganza to the

Gulf of Mexico Risk Reduction Project may require modifications to the design of the

levees, but would not impact the flood control and hurricane protection capacity of the

proposed system.

Implementation of Alternative 5 would also result in breaching the Avoca Island Levee at

feature WS4. The Avoca Island Levee is part of the East Atchafalaya Basin Protection

Levee (EABPL) and provides the Morgan City area with protection from Atchafalaya

River backwater flooding. Feature WS4 would only be operated at low to moderate

Atchafalaya River stages, and, therefore, would not increase flood heights (see Section

5.2.1 and Engineering Appendix for information on changes in water levels associated

with project implementation).

Alternative 5 would also result in the raising of the planned elevation of features CLV1

and CLV2 to accommodate potential increases in water levels due to project features in

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the area. CLV1 and CLV2 are levees currently under design by Terrebonne Parish and

are planned for future construction outside of the authority of the ARTM project.

5.15.14.2.5.2 Indirect

Implementation of Alternative 5 and the associated benefits to marshes in the project area

would be expected to provide indirect benefits to flood control and hurricane protection

levees by helping to retain the wave and storm surge buffering capacity of the marshes,

thereby decreasing storm surge and reducing wave damage.

5.15.14.2.5.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 5 would have an even greater indirect impact on flood control and

hurricane protection, as those programs would work synergistically to improve habitat

conditions across the area.

5.15.9.2.6 Alternative 6

5.15.9.2.6.1 Direct

Modifying the operation of the proposed HNC lock complex would have an impact on

water levels in the project area, but would not impact the flood control and hurricane

protection capacity of the proposed system (see Section 5.2.1 and Engineering Appendix

for information on changes in water levels associated with project implementation).

Likewise, project features that lie within the proposed alignment of the Morganza to the

Gulf of Mexico Risk Reduction Project may require modifications to the design of the

levees, but would not impact the flood control and hurricane protection capacity of the

proposed system.

Implementation of Alternative 6 would also result in breaching the Avoca Island Levee at

feature WS4. The Avoca Island Levee is part of the East Atchafalaya Basin Protection

Levee (EABPL) and provides the Morgan City area with protection from Atchafalaya

River backwater flooding. Feature WS4 would only be operated at low to moderate

Atchafalaya River stages, and, therefore, would not increase flood heights (see Section

5.2.1 and Engineering Appendix for information on changes in water levels associated

with project implementation).

5.15.9.2.6.2 Indirect

Implementation of Alternative 6 and the associated benefits to marshes in the project area

would be expected to provide indirect benefits to flood control and hurricane protection

levees by helping to retain the wave and storm surge buffering capacity of the marshes,

thereby decreasing storm surge and reducing wave damage.

5.15.9.2.6.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 6 would have an even greater indirect impact on flood control and

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hurricane protection, as those programs would work synergistically to improve habitat

conditions across the area.

5.15.9.2.7 Alternative 7

5.15.9.2.7.1 Direct

Modifying the operation of the proposed HNC lock complex would have an impact on

water levels in the project area, but would not impact the flood control and hurricane

protection capacity of the proposed system (see Section 5.2.1 and Engineering Appendix

for information on changes in water levels associated with project implementation).

5.15.9.2.7.2 Indirect

Implementation of Alternative 7 and the associated benefits to marshes in the project area

would be expected to provide indirect benefits to flood control and hurricane protection

levees by helping to retain the wave and storm surge buffering capacity of the marshes,

thereby decreasing storm surge and reducing wave damage.

5.15.9.2.7.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 7 would have an even greater indirect impact on flood control and

hurricane protection, as those programs would work synergistically to improve habitat

conditions across the area.

5.15.9.2.8 Alternative 8

5.15.9.2.8.1 Direct

Modifying the operation of the proposed HNC lock complex would have an impact on

water levels in the project area, but would not impact the flood control and hurricane

protection capacity of the proposed system (see Section 5.2.1 and Engineering Appendix

for information on changes in water levels associated with project implementation).

Likewise, project features that lie within the proposed alignment of the Morganza to the

Gulf of Mexico Risk Reduction Project may require modifications to the design of the

levees, but would not impact the flood control and hurricane protection capacity of the

proposed system.

Implementation of Alternative 8 would also result in the raising of the planned elevation

of features CLV1 and CLV2 to accommodate potential increases in water levels due to

project features in the area. CLV1 and CLV2 are levees currently under design by

Terrebonne Parish and are planned for future construction outside of the authority of the

ARTM project.

5.15.9.2.8.2 Indirect

Implementation of Alternative 8 and the associated benefits to marshes in the project area

would be expected to provide indirect benefits to flood control and hurricane protection

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levees by helping to retain the wave and storm surge buffering capacity of the marshes,

thereby decreasing storm surge and reducing wave damage.

5.15.9.2.8.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private restoration

efforts, Alternative 8 would have an even greater indirect impact on flood control and

hurricane protection, as those programs would work synergistically to improve habitat

conditions across the area.

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5.15.10 Natural Resources

5.15.10.1 Commercial Fisheries

5.15.10.1.1 No Action Alternative (Future without Project Conditions)

Concurrent with projected land loss in the project area would be an increase in saltwater

intrusion into some of the upper areas as marshes degrade. This would result in a shift in

the populations of fishes and invertebrates, with more saline-dominated species replacing

freshwater species in some areas. The band of intermediate salinity necessary for oyster

production would likely narrow significantly, and essential fish habitat for many

commercial fishery species would likewise decline, leading to a net loss in fisheries

population size and diversity.

Wetland habitat losses would decrease the productivity of Louisiana’s coastal fisheries.

The commercial fishing and seafood industry would likely suffer significant losses in

employment as estuaries that are necessary to produce shrimp, oysters, and other valuable

species erode. Job losses would occur in the areas reliant on fishing, harvesting,

processing, and shipping of the seafood catch. Thus, changes in existing fisheries habitat

caused by wetland loss, saltwater intrusion, and reduced salinity gradients would likely

increase the risk of a decline in the supply of nationally distributed seafood products from

Louisiana’s coast.

5.15.10.1.2 Alternative 2 (NER Plan and RP)

10.15.10.1.2.1 Direct

Direct impacts to commercial fisheries from implementation of Alternative 2 would

primarily be related to reduced or impeded access to fishing areas. See Section 5.15.6,

Navigation, for descriptions of these impacts.

5.15.10.1.2.2 Indirect

Implementation of Alternative 2 would have indirect impacts on commercial fisheries by

affecting the location of target species. Changes in salinity levels in the project area as a

result of project features (see Section 5.3 Water Quality and Section 5.9 Fisheries) would

change the distribution of fish and shellfish species based on their salinity tolerance.

Changes in fisheries distribution would impact commercial fishing patterns and locations.

The proposed plug in Robinson Canal would eliminate tidal currents through the canal

and would consequently eliminate the butterfly net shrimp fishery in that location.

Implementation of Alternative 2 is expected to benefit commercial fisheries by

decreasing the rate of marsh loss in the project area as compared to the No Action

Alternative. Alternative 2 is projected to provide a net benefit of 3,220 AAHUs over the

period of analysis, thereby benefitting the nationally important commercial fishing

industry in the area.

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5.15.10.1.2.3 Cumulative

Restoration efforts in the state (e.g., CWPPRA, the Community-based Restoration

Program sponsored by the NMFS Restoration Center, various state and local efforts, and

others) have aided fisheries habitat and are likely to continue to do so. Economic interest

in fisheries, and interest in Louisiana as a fishery resource for the Nation, has increased

significantly in the recent past. This increase is expected to continue and lead to changes

in fishing technology, fishing pressure, and fishing regulations, in order to maintain

sustainable commercial fisheries. It is likely that the construction of levees, water control

structures and hurricane protection features, which can result in direct loss of habitat,

alter water flow, and have the potential to block fisheries access to habitat, are likely to

continue and/or increase, as coastal residents protect themselves and their property from

hurricane damage and flooding. Implementation of Alternative 2 would contribute to an

overall benefit to commercial fisheries compared to the future with no action.

5.15.10.1.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 on commercial fisheries would

be similar to those of Alternative 2. Alternative 3 is projected to provide a net benefit of

3,325 AAHUs compared to the No Action Alternative.

5.15.10.1.4 Alternative 4

5.15.10.1.4.1 Direct

Direct impacts to commercial fisheries from implementation of Alternative 4 would

primarily be related to reduced or impeded access to fishing areas. See Section 5.15.6,

Navigation, for descriptions of these impacts.

5.15.10.1.4.2 Indirect

Indirect impacts of Alternative 4 on commercial fisheries are expected to be similar to

Alternative 2. However, reductions in salinities in the Grand Bayou basin would be

much more pronounced than with Alternative 2 (see Section 5.3 Water Quality and

Section 5.9 Fisheries). These changes in salinity would cause much more dramatic shifts

in the fish and shellfish communities in the area. Overall, Alternative 4 is projected to

provide 4,258 AAHUs compared to the No Action Alternative.

5.15.10.1.4.3 Cumulative

Cumulative impacts of Alternative 4 on commercial fisheries are expected to be similar

to Alternative 2, but to a greater degree.

5.15.10.1.5 Alternative 5

5.15.10.1.5.1 Direct

Direct impacts to commercial fisheries from implementation of Alternative 5 would

primarily be related to reduced or impeded access to fishing areas. See Section 5.15.6,

Navigation, for descriptions of these impacts.

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5.15.10.1.5.2 Indirect

Indirect impacts of Alternative 5 on fisheries resources are expected to be similar to

Alternative 2. However, reductions in salinities in the Grand Bayou basin would be

much more pronounced than with Alternative 2 (see Section 5.3 Water Quality and

Section 5.9 Fisheries). These changes in salinity would cause much more dramatic shifts

in the fish and shellfish communities in the area. Overall, Alternative 5 is projected to

provide 4,719 AAHUs compared to the No Action Alternative.

5.15.10.1.5.3 Cumulative

Cumulative impacts of Alternative 5 on commercial fisheries are expected to be similar

to Alternative 2, but to a greater degree.

5.15.10.1.6 Alternative 6

5.15.10.1.6.1 Direct

Direct impacts to commercial fisheries from implementation of Alternative 6 would

primarily be related to reduced or impeded access to fishing areas. See Section 5.15.6,

Navigation, for descriptions of these impacts.

5.15.10.1.6.2 Indirect

Indirect impacts of Alternative 6 on commercial fisheries are expected to be similar to

Alternative 2, but to a lesser degree. Alternative 6 is projected to provide a net benefit of

776 AAHUs compared to the No Action Alternative.

5.15.10.1.6.3 Cumulative

Cumulative impacts of Alternative 6 on commercial fisheries are expected to be similar

to Alternative 2, but to a lesser degree.

5.15.10.1.7 Alternative 7

5.15.10.1.7.1 Direct

Direct impacts to commercial fisheries from implementation of Alternative 7 would

primarily be related to reduced or impeded access to fishing areas. See Section 5.15.6,

Navigation, for descriptions of these impacts.

5.15.10.1.7.2 Indirect

Indirect impacts of Alternative 7 on commercial fisheries are expected to be similar to

Alternative 2, but to a lesser degree. Alternative 7 is projected to provide a net benefit of

243 AAHUs compared to the No Action Alternative.

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10.15.10.1.7.3 Cumulative

Cumulative impacts of Alternative 7 on commercial fisheries are expected to be similar

to Alternative 2, but to a lesser degree.

5.15.10.1.8 Alternative 8

5.15.10.1.8.1 Direct

Direct impacts to commercial fisheries from implementation of Alternative 8 would

primarily be related to reduced or impeded access to fishing areas. See Section 5.15.6,

Navigation, for descriptions of these impacts.

5.15.10.1.8.2 Indirect

Indirect impacts of Alternative 8 on commercial fisheries are expected to be similar to

Alternative 2, but to a lesser degree. Alternative 8 is projected to provide a net benefit of

1,214 AAHUs compared to the No Action Alternative.

5.15.10.1.8.3 Cumulative

Cumulative impacts of Alternative 8 on commercial fisheries are expected to be similar

to Alternative 2, but to a lesser degree.

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5.15.10.2 Oyster Leases

5.15.10.2.1 No Action Alternative (Future without Project Conditions)

The No Action Alternative would result in the persistence of existing conditions

including the continued conversion of transitional estuarine wetlands to open water

habitats and associated saltwater intrusion. The continued loss of transitional estuarine

wetlands would adversely affect the local detritus-based oyster food web. Organic

detritus, derived mainly from vascular plants, is a major food source for estuarine

consumers, including oysters (Day et al., 1989). Hence, the loss of wetlands in the

project area would likely reduce the localized carrying capacity for oyster leases in the

area. As oyster production from leases declines, it would likely result in lower oyster

supply, higher oyster prices, and loss of income and jobs in the oyster industry.

5.15.10.2.2 Alternative 2 (NER Plan and RP)

5.15.10.2.2.1 Direct

Table 5.8 displays information on oyster leases that would be directly impacted by

implementation of Alternative 2. Construction-related impacts to oyster leases would

include direct disturbance and/or mortality, increased turbidity and siltation, temperature

changes, and decreased dissolved oxygen. Turbidity, temperature, and dissolved oxygen

changes would return to normal following completion of construction activities. Project

features would be designed to avoid and minimize potential adverse impacts to oyster

leases and nearby Louisiana State Oyster Seed Grounds and best construction

management practices would be utilized. Oyster leases expected to be directly impacted

by the project would be acquired from the leaseholder through the LDNR’s oyster

acquisition program. Payments would be made for just compensation in accordance with

Louisiana Law.

5.15.10.2.2.2 Indirect

Direct impacts to oysters from changes in salinity levels in the project area would be

considered indirect impacts to oyster leases. Hydraulic model salinity points in relation

to oyster leases and oyster seed grounds can be found in Figure 5.37. Average monthly

salinity values at these points can be found in Table 5.9. According to these modeled

salinity values, as indicated by red-shaded areas in Table 5.9, implementation of

Alternative 2 would negatively impact oyster leases in some areas by causing salinities to

move outside of the ideal 5-15ppt range. Oyster leases in the vicinity of points B7

Southwest, New C10, D3 North, D3 Central, G6 Central, G6 Southeast, G7 Catfish Lake,

and G7 Northwest are most likely to be negatively impacted by implementation of

Alternative 2. Extended periods of salinity values below 5ppt in these areas, particularly

during periods of warmer water temperatures, are likely to cause increased mortality and

decreased reproduction. Other areas showing changes outside of the ideal 5-15ppt range

with implementation of Alternative 2, Lost Lake West, Lost Lake East, A8, and E2

Northwest, are less likely to be negatively impacted. No Action model data for these

areas shows several months of salinities already below the 5ppt range, so Alternative 2

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salinity changes are less likely to have an impact. B7 southeast is located in an area that

does not currently support oyster leases.

Over the 50-year period of analysis, Alternative 2 is projected to provide a net benefit of

3,220 AAHUs over the No Action Alternative by reducing the rate of decline of coastal

wetlands. These wetlands would provide protection and food for juvenile oysters

(source:www.nmfs.noaa.gov/habitat/habitatconservation/publications/habitatconections/n

um4.htm); increase nutrients and detritus, a major food source for oysters and other major

estuarine consumers (Day et al. 1989); increase the productivity of planktonic resources

upon which oysters feed; as well as increase the availability of catabolic products utilized

by primary producers which can then be used by oysters and other species (Kilgen and

Dugas 1989).

Table 5.8. State Oyster Leases Potentially Impacted by Project Features.

Project Feature Lease Number(s)

Impacted

Expiration Date Anticipated

Acreage Impacted

WW2 34676 1/1/2010 9.2 acres

WP1 35188

3147906

1/1/2012

1/1/2021

3.46 acres

CM2 34154 1/1/2010 2 acres

CT8 3364909

34154

1/1/2024

1/1/2010

92 acres

CM2 & CT1 34208 1/1/2010 .52 acres

CP1 3081005

2967703

2908902

1/1/2020

1/1/2018

1/1/2017

1.62 acres

CT2 & CT3 35277

34650

35458

1/1/2012

1/1/2010

1/1/2012

110.5 acres

EM3 2674398

34928

2913605

34865

2687198

3395309

1/1/2013

1/1/2011

1/1/2020

1/1/2011

1/1/2013

1/1/2024

3 acres

Total Lease Acreage

Impacted

222.3 acres

5.15.10.2.2.3 Cumulative

Potential negative impacts of Alternative 2 on oyster leases due to salinity impacts would

likely be outweighed by the benefits it would provide in prevention of marsh loss. When

combined with CWPPRA and other Federal, state, local, and private marsh restoration

efforts, Alternative 2 would have an even greater indirect impact on oyster leases, as

those programs would work synergistically to improve habitat conditions across the area.

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5.15.10.2.3 Alternative 3

5.15.10.2.3.1 Direct

Direct, indirect, and cumulative impacts of Alternative 3 on oyster leases would be

similar to those of Alternative 2.

5.15.10.2.4 Alternative 4

5.15.10.2.4.1 Direct

Direct impacts of Alternative 4 on oyster leases would be similar to those of Alternative 2.

5.15.10.2.4.2 Indirect

Indirect impacts of Alternative 4 on oyster leases in the western and central areas would

be similar to those of Alternative 2. However, due to implementation of the pump station

at Grand Bayou, salinity decreases in the Grand Bayou basin would be much more

pronounced (see Table 5.9). Oyster leases in the vicinity of G6 Central and G6 Southeast

would likely not support oysters with implementation of Alternative 4 due to extended

periods with salinities far below the 5ppt range. Oyster leases in the vicinity of G7

Catfish Lake and G7 Northwest would likely see increased mortality and decreased

reproduction. Oyster leases in the vicinity of G7 Southeast, however, would likely

benefit from implementation of Alternative 4 through decreased predation and disease

due to reductions in salinities into the 5-15ppt range.

Overall, Alternative 4 is projected to provide a net benefit of 4,258 AAHUs over the No

Action Alternative by reducing the rate of decline of coastal wetlands.

5.15.10.2.4.3 Cumulative

Potential negative impacts of Alternative 4 on oyster leases due to salinity impacts would

likely be outweighed by the benefits it would provide in prevention of marsh loss. When

combined with CWPPRA and other Federal, state, local, and private marsh restoration

efforts, Alternative 4 would have an even greater indirect impact on oyster leases, as

those programs would work synergistically to improve habitat conditions across the area.

5.15.10.2.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 on oyster leases would be

similar to those of Alternative 4.

5.15.10.2.6 Alternative 6

5.15.10.2.6.1 Direct

No direct impacts to oyster leases are anticipated from implementation of Alternative 6.

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5.15.10.2.6.2 Indirect

According to modeled salinity values (Table 5.9), Alternative 6 would cause salinities in

several areas to fall below the ideal 5-15ppt range. Most of the changes are minor,

however, and only two areas are likely to see major changes in oyster production:

Robinson Canal and G6 Central. Oysters in these areas would likely see increased

mortality and decreased reproduction. Many areas also show improvements in salinities

(Table 5.9). These areas would likely see reduced disease and predation with

implementation of Alternative 6.

Overall, Alternative 6 is projected to provide a net benefit of 776 AAHUs over the No

Action Alternative by reducing the rate of decline of coastal wetlands.

5.15.10.2.6.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private marsh

restoration efforts, Alternative 6 would have an even greater indirect impact on oyster

leases, as those programs would work synergistically to improve habitat conditions across

the area.

5.15.10.2.7 Alternative 7

5.15.10.2.7.1 Direct

No direct impacts to oyster leases are anticipated from implementation of Alternative 7.

5.15.10.2.7.2 Indirect

According to modeled salinity values (Table 5.9), Alternative 7 would cause salinities in

several areas to fall below the ideal 5-15ppt range. However, most of the changes are

minor and only the Robinson Canal area is likely to be negatively impacted. Oysters in

this area would likely see increased mortality and decreased reproduction. Several areas

also show slight improvements in salinities. However, the changes are minor and would

not be expected to have a major impact on oyster production.

Overall, Alternative 7 is projected to provide a net benefit of 243 AAHUs over the No

Action Alternative by reducing the rate of decline of coastal wetlands.

5.15.10.2.7.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private marsh

restoration efforts, Alternative 7 would have an even greater indirect impact on oyster

leases, as those programs would work synergistically to improve habitat conditions across

the area.

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5.15.10.2.8 Alternative 8

5.15.10.2.8.1 Direct

Direct impacts of Alternative 8 on oyster leases would be similar to those of Alternative 2,

but to a lesser degree. Direct impacts would occur only in association with construction of

feature CP1.

5.15.10.2.8.2 Indirect

According to modeled salinity values (Table 5.9), indirect impacts of Alternative 8 on

oyster leases would be similar to Alternative 2.

Overall, Alternative 8 is projected to provide a net benefit of 1,214 AAHUs over the No

Action Alternative by reducing the rate of decline of coastal wetlands.

5.15.10.2.8.3 Cumulative

When combined with CWPPRA and other Federal, state, local, and private marsh

restoration efforts, Alternative 8 would have an even greater indirect impact on oyster

leases, as those programs would work synergistically to improve habitat conditions across

the area.

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Figure 5.37. Locations of Hydraulic Model Salinity Points with Overlay of Current (August 2009) Oyster Lease and Seed Ground Locations.

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Final EIS WRDA 2007 Section 7006(e)(3) September 2010Table 5.9. Modeled Average Monthly Salinity Values by Area in 2025.Gray shaded areas in the No Action section indicate months where the RP is predicted to cause a change into or out of the ideal oystersalinity range of 5-15 ppt. Red shaded areas indicate months where No Action salinities were in the ideal 5-15 ppt range and theAlternative caused a shift outside of the ideal range. Green shaded areas indicate months where No Action salinities were outside ofthe ideal range and the Alternative caused a shift into the ideal range.No Action

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 7.1 9.0 3.6 15.8 13.4 17.6 19.3 12.1 8.8 9.3 10.7 12.2 15.7 18.8 13.0 13.3 11.2 17.4 17.5 18.3 16.3 17.1 18.3 11.2 14.6 16.4 16.4 18.2Feb 4.8 5.9 2.3 12.4 10.4 14.3 16.4 8.6 8.3 8.7 9.5 10.4 13.0 15.9 11.1 11.4 8.0 15.1 15.2 15.7 14.2 14.8 15.6 9.9 12.6 14.1 14.2 15.5Mar 3.0 3.4 1.3 9.6 8.0 11.6 14.0 5.9 7.9 8.3 8.6 8.9 10.8 13.5 9.7 9.9 5.4 13.2 13.3 13.6 12.6 13.0 13.5 8.9 11.1 12.3 12.4 13.4Apr 3.2 3.6 1.4 9.8 8.2 11.8 14.2 6.1 7.9 8.3 8.6 9.0 11.0 13.7 9.8 10.0 5.6 13.3 13.4 13.7 12.7 13.1 13.7 9.0 11.2 12.4 12.5 13.5May 0.6 0.1 0.0 5.9 4.8 8.0 10.9 2.2 7.4 7.7 7.3 6.9 8.0 10.4 7.7 7.8 1.9 10.7 10.8 10.8 10.3 10.6 10.7 7.5 9.0 9.9 10.1 10.5Jun 1.9 1.9 0.7 7.9 6.6 9.9 12.6 4.2 7.7 8.0 8.0 8.0 9.5 12.0 8.7 8.9 3.8 12.1 12.1 12.3 11.5 11.9 12.2 8.3 10.1 11.2 11.3 12.0Jul 7.6 9.6 3.8 16.5 14.0 18.3 19.9 12.8 8.9 9.4 10.9 12.6 16.2 19.4 13.4 13.7 11.9 17.8 18.0 18.8 16.7 17.6 18.8 11.5 15.0 16.9 16.8 18.8Aug 10.9 14.0 5.6 21.6 18.3 23.2 24.1 17.7 9.5 10.3 12.6 15.2 20.1 23.6 16.1 16.4 16.5 21.2 21.4 22.6 19.8 20.9 22.6 13.3 17.7 20.2 20.0 22.6Sep 10.9 14.1 5.6 21.6 18.4 23.3 24.2 17.8 9.5 10.3 12.6 15.2 20.1 23.7 16.1 16.4 16.6 21.2 21.4 22.7 19.8 20.9 22.7 13.4 17.8 20.2 20.0 22.7Oct 10.5 13.8 5.1 21.8 18.7 23.6 24.3 19.7 9.0 9.7 12.1 14.6 19.7 23.8 16.0 16.4 16.0 21.2 21.4 22.8 19.6 20.8 22.8 12.6 17.3 20.0 19.8 22.7Nov 11.0 14.5 5.4 22.7 19.5 24.4 25.1 20.5 9.2 9.9 12.5 15.1 20.5 24.6 16.5 16.9 16.8 21.7 22.0 23.4 20.1 21.4 23.4 12.9 17.8 20.6 20.3 23.4Dec 10.5 13.5 5.4 21.0 17.8 22.6 23.6 17.2 9.5 10.2 12.4 14.9 19.6 23.2 15.8 16.1 16.0 20.8 21.0 22.2 19.4 20.5 22.2 13.1 17.4 19.8 19.6 22.2Alternative 2

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 4.8 5.3 2.1 15.0 12.9 18.0 19.3 13.9 6.4 8.4 11.2 10.8 14.6 18.5 13.1 13.4 10.8 17.7 17.8 18.5 17.1 17.2 18.1 8.9 11.5 13.8 13.9 16.7Feb 3.2 3.5 1.3 11.0 8.9 14.6 16.4 10.2 4.7 7.7 11.0 8.0 10.8 15.4 11.2 11.4 7.5 15.2 15.3 15.8 14.6 14.6 15.3 6.1 8.0 10.1 10.4 13.1Mar 1.8 2.0 0.8 7.8 5.8 12.0 14.1 7.2 3.3 7.1 10.8 5.8 7.7 13.0 9.6 9.8 4.9 13.2 13.3 13.6 12.6 12.5 13.1 3.9 5.3 7.2 7.6 10.3Apr 1.9 2.1 0.8 8.0 6.1 12.1 14.2 7.4 3.4 7.1 10.8 5.9 7.9 13.1 9.8 10.0 5.1 13.3 13.5 13.8 12.7 12.6 13.2 4.0 5.5 7.4 7.8 10.5May 0.1 0.0 0.0 3.5 1.6 8.4 10.9 3.2 1.4 6.3 10.6 2.8 3.5 9.6 7.6 7.7 1.3 10.5 10.6 10.7 9.9 9.7 10.0 0.9 1.6 3.2 3.8 6.5Jun 1.0 1.1 0.4 5.8 3.9 10.3 12.6 5.3 2.4 6.7 10.7 4.4 5.8 11.4 8.7 8.9 3.2 11.9 12.1 12.3 11.4 11.2 11.6 2.5 3.5 5.3 5.8 8.6Jul 5.2 5.7 2.2 15.8 13.6 18.6 19.9 14.7 6.8 8.6 11.2 11.4 15.4 19.2 13.5 13.8 11.4 18.2 18.4 19.0 17.6 17.8 18.7 9.4 12.2 14.6 14.6 17.4Aug 7.6 8.4 3.3 21.6 19.3 23.5 24.1 20.1 9.3 9.7 11.5 15.5 21.0 23.6 16.4 16.6 16.2 21.8 22.0 23.0 21.2 21.6 22.8 13.5 17.2 19.9 19.6 22.5Sep 7.6 8.4 3.3 21.6 19.4 23.5 24.2 20.2 9.4 9.7 11.5 15.5 21.1 23.7 16.4 16.6 16.2 21.8 22.0 23.0 21.3 21.6 22.8 13.5 17.3 20.0 19.7 22.6Oct 7.7 8.6 3.3 21.9 19.6 23.7 24.4 20.4 9.5 9.7 11.5 15.7 21.3 23.9 16.5 16.8 16.4 21.9 22.2 23.2 21.4 21.8 23.0 13.7 17.5 20.2 19.9 22.8Nov 8.1 9.0 3.5 22.8 20.5 24.5 25.1 21.3 9.9 9.9 11.6 16.4 22.2 24.6 17.0 17.2 17.2 22.5 22.8 23.8 22.0 22.4 23.7 14.3 18.3 21.1 20.7 23.6Dec 7.3 8.1 3.1 20.9 18.6 22.9 23.7 19.5 9.0 9.6 11.5 15.0 20.3 23.1 16.0 16.3 15.6 21.3 21.6 22.5 20.8 21.1 22.3 13.0 16.7 19.3 19.0 21.9

454
Environmental Consequences Volume III – Convey Atchafalaya River Water to Northern Terrebonne

Marshes and Multipurpose Operation of Houma Navigation Lock

5-192

Final EIS WRDA 2007 Section 7006(e)(3) September 2010Alternative 3

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 4.8 5.3 2.1 14.9 12.8 17.9 19.3 13.9 6.4 8.4 11.2 10.8 14.6 18.5 13.2 13.4 10.7 17.6 17.8 18.5 17.1 17.2 18.1 8.8 11.4 13.7 13.8 16.6Feb 3.2 3.5 1.3 10.9 8.8 14.6 16.4 10.1 4.7 7.6 10.9 8.0 10.7 15.4 11.2 11.4 7.4 15.1 15.3 15.8 14.6 14.6 15.3 6.0 7.9 10.0 10.2 13.0Mar 1.8 2.0 0.8 7.8 5.8 12.0 14.1 7.2 3.3 7.1 10.8 5.8 7.7 13.0 9.7 9.9 4.9 13.2 13.3 13.6 12.6 12.5 13.1 3.9 5.3 7.2 7.6 10.3Apr 1.9 2.1 0.8 8.0 6.0 12.1 14.2 7.4 3.4 7.1 10.8 5.9 7.9 13.1 9.8 10.0 5.0 13.3 13.5 13.8 12.7 12.6 13.2 4.0 5.5 7.4 7.8 10.5May 0.1 0.0 0.0 3.5 1.6 8.4 10.9 3.2 1.4 6.3 10.6 2.8 3.5 9.6 7.6 7.7 1.3 10.5 10.6 10.7 9.9 9.7 10.0 0.9 1.6 3.2 3.8 6.5Jun 1.0 1.1 0.4 5.8 3.9 10.3 12.6 5.3 2.4 6.7 10.7 4.4 5.8 11.4 8.7 8.9 3.2 11.9 12.1 12.3 11.4 11.2 11.6 2.5 3.5 5.3 5.8 8.6Jul 5.2 5.7 2.2 15.7 13.6 18.6 19.9 14.6 6.8 8.6 11.2 11.4 15.4 19.1 13.6 13.8 11.4 18.1 18.3 19.0 17.6 17.7 18.7 9.4 12.1 14.5 14.5 17.3Aug 7.6 8.4 3.2 21.5 19.3 23.5 24.1 20.1 9.3 9.7 11.5 15.4 21.0 23.6 16.4 16.7 16.1 21.8 22.0 23.0 21.2 21.6 22.8 13.4 17.2 19.9 19.6 22.5Sep 7.6 8.4 3.2 21.6 19.3 23.5 24.2 20.2 9.3 9.7 11.5 15.5 21.0 23.7 16.5 16.7 16.2 21.8 22.0 23.0 21.3 21.6 22.8 13.5 17.3 19.9 19.7 22.5Oct 7.7 8.5 3.3 21.8 19.5 23.7 24.4 20.4 9.4 9.7 11.5 15.6 21.2 23.9 16.6 16.8 16.4 21.9 22.2 23.2 21.4 21.8 23.0 13.6 17.4 20.2 19.9 22.7Nov 8.1 9.0 3.5 22.8 20.5 24.5 25.1 21.3 9.8 9.9 11.6 16.3 22.2 24.6 17.0 17.3 17.2 22.5 22.8 23.8 22.0 22.4 23.7 14.3 18.3 21.1 20.7 23.6Dec 7.3 8.1 3.1 20.9 18.6 22.9 23.7 19.5 9.0 9.6 11.5 15.0 20.3 23.1 16.1 16.3 15.6 21.3 21.6 22.5 20.8 21.1 22.3 13.0 16.6 19.3 19.0 21.9Alternative 4

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 5.3 6.0 2.8 15.3 13.5 18.1 19.3 14.7 7.4 8.7 11.3 12.5 15.2 18.5 12.8 13.1 13.0 17.0 17.3 18.2 15.4 15.1 16.8 1.7 2.2 4.2 4.7 9.3Feb 3.5 3.9 1.8 11.2 9.4 14.7 16.4 10.7 5.3 7.8 11.1 9.1 11.2 15.4 10.9 11.2 9.0 14.7 15.0 15.6 13.5 13.2 14.4 1.4 1.9 3.7 4.2 8.2Mar 2.0 2.2 1.0 7.9 6.1 12.0 14.1 7.5 3.6 7.2 10.8 6.4 7.9 13.0 9.5 9.7 5.8 12.9 13.1 13.5 11.9 11.6 12.5 1.2 1.7 3.3 3.9 7.2Apr 2.1 2.4 1.1 8.2 6.3 12.2 14.2 7.7 3.7 7.2 10.8 6.6 8.1 13.1 9.6 9.8 6.0 13.0 13.2 13.6 12.0 11.7 12.6 1.2 1.7 3.4 3.9 7.3May 0.1 0.0 0.0 3.6 1.7 8.4 10.9 3.2 1.4 6.3 10.5 2.8 3.6 9.6 7.5 7.7 1.4 10.5 10.6 10.7 9.8 9.6 9.9 0.8 1.4 2.8 3.4 6.0Jun 1.1 1.2 0.6 5.9 4.0 10.3 12.6 5.5 2.6 6.7 10.7 4.7 5.9 11.4 8.6 8.8 3.7 11.8 12.0 12.2 10.9 10.7 11.3 1.0 1.5 3.1 3.7 6.7Jul 5.6 6.4 3.0 16.1 14.3 18.8 19.9 15.5 7.8 8.8 11.4 13.1 16.1 19.2 13.1 13.5 13.9 17.4 17.8 18.7 15.8 15.5 17.2 1.8 2.2 4.3 4.8 9.6Aug 8.3 9.4 4.4 22.0 20.3 23.6 24.1 21.3 10.8 10.1 11.8 18.0 21.9 23.6 15.7 16.2 19.7 20.7 21.1 22.5 18.6 18.3 20.7 2.2 2.7 5.0 5.4 11.2Sep 8.3 9.4 4.4 22.1 20.4 23.7 24.2 21.4 10.8 10.1 11.8 18.1 22.0 23.7 15.8 16.2 19.8 20.8 21.2 22.5 18.6 18.3 20.7 2.2 2.7 5.0 5.4 11.3Oct 8.4 9.6 4.4 22.3 20.6 23.9 24.3 21.6 10.9 10.1 11.8 18.3 22.2 23.9 15.9 16.3 20.0 20.9 21.3 22.7 18.7 18.4 20.8 2.2 2.7 5.1 5.4 11.3Nov 8.8 10.1 4.7 23.3 21.6 24.7 25.0 22.6 11.4 10.3 11.9 19.1 23.2 24.6 16.3 16.8 21.0 21.4 21.9 23.3 19.2 18.9 21.4 2.3 2.7 5.2 5.5 11.6Dec 8.0 9.1 4.2 21.3 19.6 23.1 23.6 20.6 10.4 9.9 11.8 17.5 21.2 23.1 15.4 15.9 19.0 20.3 20.7 22.0 18.3 17.9 20.3 2.2 2.6 4.9 5.3 11.0

455
Environmental Consequences Volume III – Convey Atchafalaya River Water to Northern Terrebonne

Marshes and Multipurpose Operation of Houma Navigation Lock

5-193

Final EIS WRDA 2007 Section 7006(e)(3) September 2010Alternative 5

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 5.2 5.9 2.7 15.2 13.4 18.0 19.3 14.6 7.3 8.6 11.3 12.4 15.2 18.5 12.7 13.1 13.0 17.0 17.3 18.2 15.4 15.1 16.8 1.7 2.2 4.2 4.7 9.3Feb 3.4 3.9 1.8 11.1 9.3 14.6 16.4 10.6 5.2 7.8 11.0 9.0 11.1 15.4 10.9 11.2 8.9 14.7 15.0 15.6 13.5 13.2 14.4 1.4 1.9 3.7 4.2 8.2Mar 2.0 2.2 1.0 7.9 6.1 12.0 14.1 7.5 3.6 7.2 10.8 6.4 7.9 13.0 9.5 9.7 5.8 12.9 13.1 13.5 11.9 11.6 12.5 1.2 1.7 3.3 3.9 7.2Apr 2.1 2.3 1.1 8.2 6.3 12.2 14.2 7.7 3.7 7.2 10.8 6.6 8.1 13.1 9.6 9.8 6.0 13.0 13.2 13.6 12.0 11.7 12.6 1.2 1.7 3.4 3.9 7.3May 0.1 0.0 0.0 3.6 1.7 8.4 10.9 3.2 1.4 6.3 10.5 2.8 3.6 9.6 7.5 7.7 1.4 10.5 10.6 10.7 9.8 9.6 9.9 0.8 1.4 2.8 3.4 6.0Jun 1.1 1.2 0.6 5.9 4.0 10.3 12.6 5.5 2.6 6.7 10.7 4.7 5.9 11.4 8.6 8.8 3.7 11.8 12.0 12.2 10.9 10.7 11.3 1.0 1.5 3.1 3.7 6.7Jul 5.6 6.4 2.9 16.0 14.3 18.7 19.9 15.4 7.7 8.8 11.4 13.1 16.0 19.1 13.1 13.5 13.8 17.4 17.8 18.7 15.8 15.5 17.2 1.8 2.2 4.3 4.8 9.6Aug 8.2 9.3 4.3 22.0 20.3 23.6 24.1 21.3 10.7 10.1 11.8 18.0 21.9 23.6 15.7 16.2 19.7 20.7 21.1 22.5 18.6 18.3 20.7 2.2 2.7 5.0 5.4 11.3Sep 8.3 9.4 4.3 22.1 20.3 23.7 24.2 21.3 10.8 10.1 11.8 18.0 22.0 23.7 15.8 16.2 19.8 20.8 21.2 22.5 18.6 18.3 20.7 2.2 2.7 5.0 5.4 11.3Oct 8.4 9.5 4.4 22.3 20.6 23.9 24.3 21.6 10.9 10.1 11.8 18.2 22.2 23.9 15.9 16.3 20.0 20.9 21.3 22.7 18.7 18.4 20.8 2.2 2.7 5.1 5.5 11.3Nov 8.8 10.0 4.6 23.3 21.6 24.7 25.0 22.5 11.4 10.3 11.9 19.0 23.2 24.6 16.3 16.8 21.0 21.4 21.9 23.3 19.2 18.9 21.4 2.3 2.7 5.2 5.6 11.6Dec 7.9 9.0 4.2 21.3 19.6 23.1 23.6 20.6 10.4 9.9 11.8 17.4 21.2 23.1 15.4 15.9 19.0 20.3 20.7 22.0 18.3 17.9 20.3 2.2 2.6 5.0 5.3 11.1Alternative 6

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 6.9 8.7 3.2 13.5 11.8 14.5 14.9 12.2 5.9 6.4 7.9 9.3 12.3 14.6 9.8 10.1 9.9 12.9 13.1 14.0 12.1 12.9 14.0 8.5 10.9 12.2 12.4 13.9Feb 4.5 5.6 2.1 8.8 7.7 9.5 9.7 8.0 3.9 4.1 5.1 6.0 8.0 9.5 6.4 6.5 6.5 8.4 8.6 9.1 7.9 8.4 9.1 5.5 7.1 7.9 8.1 9.1Mar 3.0 3.3 1.2 8.6 6.3 12.1 14.0 7.2 7.2 6.0 5.0 7.2 7.9 12.8 9.3 9.6 5.2 12.5 12.8 13.3 11.4 12.1 13.2 5.0 7.3 9.5 10.1 12.2Apr 3.1 3.5 1.3 8.8 6.5 12.2 14.2 7.4 7.2 6.1 5.1 7.3 8.1 13.0 9.4 9.7 5.4 12.7 12.9 13.5 11.5 12.2 13.3 5.1 7.5 9.7 10.3 12.4May 0.5 0.1 0.0 4.6 2.5 8.5 10.9 3.4 6.3 4.7 2.6 4.8 4.3 9.5 7.2 7.5 1.9 9.9 10.1 10.4 8.8 9.4 10.2 2.3 4.2 6.3 7.1 9.0Jun 1.9 1.8 0.7 6.7 4.5 10.4 12.5 5.4 6.8 5.4 3.9 6.1 6.2 11.3 8.3 8.6 3.7 11.3 11.5 12.0 10.2 10.8 11.8 3.7 5.9 8.0 8.7 10.7Jul 7.4 9.3 3.5 14.5 12.6 15.5 15.9 13.1 6.4 6.8 8.4 9.9 13.1 15.6 10.5 10.8 10.6 13.9 14.1 15.0 13.0 13.8 15.0 9.1 11.7 13.0 13.2 14.9Aug 10.9 13.6 5.1 21.3 18.5 22.8 23.4 19.2 9.3 10.0 12.4 14.6 19.3 23.0 15.5 15.8 15.6 20.4 20.7 22.0 19.1 20.2 22.0 13.4 17.2 19.2 19.5 22.0Sep 10.9 13.7 5.1 21.4 18.6 22.9 23.5 19.3 9.4 10.1 12.5 14.7 19.4 23.1 15.5 15.9 15.7 20.5 20.8 22.1 19.2 20.3 22.1 13.5 17.3 19.2 19.5 22.0Oct 11.1 13.9 5.2 21.7 18.9 23.2 23.8 19.6 9.5 10.2 12.6 14.8 19.6 23.3 15.7 16.1 15.9 20.7 21.0 22.4 19.4 20.6 22.4 13.6 17.5 19.5 19.8 22.3Nov 11.7 14.6 5.4 22.8 19.8 24.4 25.1 20.6 10.0 10.7 13.3 15.6 20.7 24.6 16.5 16.9 16.7 21.8 22.1 23.5 20.4 21.6 23.5 14.3 18.4 20.5 20.8 23.5Dec 10.5 13.1 4.9 20.5 17.9 22.0 22.6 18.5 9.0 9.6 11.9 14.1 18.6 22.1 14.9 15.2 15.0 19.6 19.9 21.2 18.4 19.5 21.2 12.9 16.6 18.4 18.7 21.1

456
Environmental Consequences Volume III – Convey Atchafalaya River Water to Northern Terrebonne

Marshes and Multipurpose Operation of Houma Navigation Lock

5-194

Final EIS WRDA 2007 Section 7006(e)(3) September 2010Alternative 7

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 6.8 8.6 3.2 15.3 12.6 18.0 19.3 13.6 8.0 7.8 8.5 10.9 13.9 18.4 12.9 13.2 10.6 17.2 17.4 18.2 16.1 16.9 18.2 10.7 14.2 16.2 16.1 18.1Feb 4.6 5.7 2.1 11.6 9.0 14.7 16.4 10.0 7.4 6.7 6.4 8.8 10.5 15.3 11.0 11.3 7.5 14.9 15.0 15.6 14.0 14.7 15.6 9.5 12.4 14.0 14.0 15.5Mar 2.9 3.3 1.2 8.6 6.2 12.1 14.0 7.1 6.9 5.9 4.8 7.0 7.8 12.8 9.6 9.8 5.0 13.0 13.2 13.5 12.4 12.9 13.5 8.6 10.9 12.2 12.3 13.3Apr 3.0 3.5 1.3 8.8 6.4 12.2 14.2 7.3 7.0 5.9 4.9 7.2 8.0 13.0 9.7 9.9 5.2 13.2 13.3 13.7 12.5 13.0 13.6 8.7 11.0 12.3 12.4 13.5May 0.5 0.1 0.0 4.6 2.4 8.5 10.9 3.3 6.3 4.7 2.6 4.7 4.2 9.5 7.6 7.8 1.7 10.6 10.7 10.7 10.2 10.5 10.7 7.4 8.9 9.8 10.0 10.5Jun 1.8 1.8 0.6 6.7 4.5 10.4 12.6 5.4 6.6 5.3 3.8 6.0 6.1 11.3 8.6 8.8 3.5 11.9 12.0 12.2 11.4 11.8 12.2 8.0 10.0 11.1 11.2 12.0Jul 7.2 9.2 3.4 16.1 13.3 18.6 19.9 14.3 8.1 8.0 8.9 11.4 14.6 19.1 13.3 13.6 11.3 17.7 17.9 18.8 16.5 17.4 18.8 10.9 14.6 16.6 16.6 18.7Aug 10.4 13.6 5.0 21.5 18.4 23.4 24.1 19.4 9.0 9.6 11.9 14.5 19.4 23.6 15.9 16.3 15.8 21.0 21.2 22.6 19.5 20.7 22.6 12.5 17.2 19.9 19.7 22.5Sep 10.4 13.6 5.1 21.6 18.5 23.5 24.2 19.5 9.0 9.6 11.9 14.5 19.5 23.6 15.9 16.3 15.8 21.0 21.3 22.6 19.5 20.7 22.6 12.6 17.2 19.9 19.7 22.6Oct 10.5 13.8 5.1 21.8 18.7 23.6 24.3 19.7 9.0 9.7 12.1 14.6 19.7 23.8 16.0 16.4 16.0 21.2 21.4 22.8 19.6 20.8 22.8 12.6 17.3 20.0 19.8 22.7Nov 11.0 14.5 5.4 22.7 19.5 24.4 25.1 20.5 9.2 9.9 12.5 15.1 20.5 24.6 16.5 16.9 16.8 21.7 22.0 23.4 20.1 21.4 23.4 12.9 17.8 20.6 20.3 23.4Dec 10.0 13.1 4.9 20.9 17.8 22.8 23.6 18.8 8.9 9.4 11.6 14.1 18.9 23.0 15.6 16.0 15.3 20.6 20.9 22.1 19.1 20.3 22.1 12.4 16.9 19.5 19.3 22.1Alternative 8

Month

Lost

Lake

West

Lost

Lake

East A8

B7

South

West

B7

South

East

C14

Central

C14

South

HNC

South

New

C10

Bayou

Dulac

Robin

son

Canal

D3

North

D3

Central

D3

South

E3

North

E3

South

E2

North

West

E2

South

East

E4

North

E4

South F2

F3

North

F3

South

G6

Central

G6

South

East

G7

Catfish

Lake

G7

North

West

G7

South

East

Jan 7.2 8.9 3.7 15.4 12.8 18.0 19.3 13.8 6.4 8.3 11.6 10.9 14.7 18.6 13.2 13.4 10.9 17.7 17.9 18.5 17.1 17.3 18.1 8.7 11.5 13.6 14.1 16.8Feb 4.9 5.8 2.4 11.6 9.2 14.7 16.4 10.2 4.6 7.6 11.6 8.0 10.9 15.5 11.2 11.4 7.5 15.2 15.4 15.8 14.7 14.7 15.3 6.1 8.1 10.1 10.8 13.4Mar 3.1 3.4 1.4 8.6 6.3 12.1 14.0 7.3 3.2 7.0 11.6 5.8 7.8 13.0 9.7 9.9 4.9 13.2 13.4 13.6 12.7 12.6 13.1 4.0 5.5 7.3 8.1 10.6Apr 3.2 3.5 1.4 8.8 6.5 12.2 14.2 7.5 3.3 7.1 11.6 6.0 8.0 13.2 9.8 10.0 5.1 13.3 13.5 13.8 12.8 12.7 13.3 4.1 5.7 7.5 8.3 10.8May 0.6 0.1 0.0 4.5 2.4 8.5 10.9 3.4 1.3 6.2 11.6 2.8 3.7 9.7 7.6 7.8 1.4 10.5 10.7 10.7 10.0 9.8 10.1 1.1 1.9 3.5 4.5 7.0Jun 1.9 1.8 0.7 6.7 4.5 10.4 12.6 5.5 2.3 6.7 11.6 4.4 5.9 11.5 8.7 8.9 3.3 12.0 12.1 12.3 11.4 11.3 11.7 2.6 3.8 5.5 6.4 8.9Jul 7.7 9.5 3.9 16.2 13.6 18.7 19.9 14.6 6.8 8.5 11.6 11.4 15.5 19.2 13.6 13.8 11.5 18.2 18.4 19.0 17.6 17.8 18.7 9.3 12.2 14.4 14.8 17.5Aug 11.1 13.9 5.7 21.7 18.8 23.4 24.1 19.8 9.4 9.5 11.7 15.5 21.0 23.6 16.4 16.6 16.3 21.8 22.0 23.0 21.2 21.6 22.8 13.1 17.0 19.5 19.7 22.4Sep 11.1 13.9 5.8 21.8 18.9 23.5 24.2 19.9 9.4 9.5 11.7 15.5 21.1 23.7 16.4 16.6 16.4 21.8 22.0 23.0 21.3 21.6 22.8 13.2 17.0 19.6 19.7 22.5Oct 11.2 14.1 5.8 22.0 19.1 23.7 24.4 20.1 9.5 9.5 11.7 15.7 21.3 23.9 16.5 16.8 16.5 22.0 22.2 23.2 21.4 21.8 23.0 13.3 17.2 19.8 19.9 22.7Nov 11.8 14.8 6.1 22.9 20.0 24.5 25.1 21.0 10.0 9.7 11.7 16.4 22.2 24.6 17.0 17.2 17.3 22.6 22.8 23.8 22.0 22.4 23.7 14.0 18.0 20.6 20.7 23.5Dec 10.7 13.4 5.5 21.1 18.2 22.9 23.7 19.2 9.1 9.4 11.7 15.0 20.4 23.1 16.0 16.3 15.8 21.4 21.6 22.5 20.8 21.2 22.3 12.7 16.4 18.9 19.1 21.9

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5.16 Hazardous, Toxic, and Radioactive Wastes

[Phase I Environmental Site Assessment Findings]

5.16.1 No Action Alternative (Future without Project Conditions)

The condition with the No Action Alternative regarding the potential for HTRW is

dependent on site-specific HTRW discovery. Based on the Phase I Environmental Site

Assessment in the project action area, there is reason to believe that the potential to

encounter HTRW problems would be low.

5.16.2 Alternative 2 (NER Plan and RP)

5.16.2.1 Direct

Consistent with ER 1165-2-132, an HTRW investigation of the project area was

conducted. Based upon findings from this investigation, the potential for direct impacts

to the project area from implementation of Alternative 2 would be low and would likely

continue to be low into the future.

5.16.2.2 Indirect

Consistent with ER 1165-2-132, an HTRW investigation of the project area was

conducted. Based upon findings from this investigation, the potential for indirect impacts

to the project area from implementation of Alternative 2 would be low and would likely

continue to be low into the future.

5.16.2.3 Cumulative

Consistent with ER 1165-2-132, an HTRW investigation of the project area was

conducted. Based upon findings from this investigation, the potential for cumulative

impacts to the project area from implementation of Alternative 2 would be low and would

likely continue to be low into the future.

5.16.3 Alternative 3

Direct, indirect, and cumulative impacts of Alternative 3 would be similar to Alternative 2.

5.16.4 Alternative 4

Direct, indirect, and cumulative impacts of Alternative 4 would be similar to Alternative 2.

5.16.5 Alternative 5

Direct, indirect, and cumulative impacts of Alternative 5 would be similar to Alternative 2.

5.16.6 Alternative 6

Direct, indirect, and cumulative impacts of Alternative 6 would be similar to Alternative 2.

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5.16.7 Alternative 7

Direct, indirect, and cumulative impacts of Alternative 7 would be similar to Alternative 2.

5.16.8 Alternative 8

Direct, indirect, and cumulative impacts of Alternative 8 would be similar to Alternative 2.

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5.17 Unavoidable Adverse Effects

Wetland impacts were avoided and minimized to the extent possible in the preliminary

design of the RP. With avoidance and minimization of wetland impacts the RP would

impact approximately 171 acres of swamp/wetland forest, 343 acres of fresh marsh, 248

acres of intermediate marsh, and 182 acres of brackish marsh due to dredge features

WD2, CD1, CD3, CD6, CD7, ED2, ED3, ED6, and ED7 and due to levee features CLV1

and CLV2. The creation of approximately 329 acres of emergent marsh habitat and the

prevention of loss of approximately 9,655 acres of emergent marsh habitat will mitigate

for the wetland impacts resulting from construction project features. There would be no

other unavoidable adverse impacts as a result of the implementation of reasonable

alternatives for this project.

5.18 Relationship of Short-Term Uses and Long-Term Productivity

NEPA Section 102(2)(c)(iv) and 40 CFR 1502.16 requires that an EIS include a

discussion of the relationship between short-term uses of the environment and the

maintenance and enhancement of long-term productivity. This section describes how the

Proposed Action would affect the short-term use and the long-term productivity of the

environment.

In reference to the Proposed Action, “short-term” refers to the temporary phase of

construction of the proposed project, while “long-term” refers to the operational life of

the proposed project and beyond. Section 5 of this document evaluates the direct,

indirect and cumulative effects that could result from the Proposed Action.

Construction of the Proposed Action would result in short-term construction-related

impacts within parts of the project area and would include to some extent interference

with local traffic, minor limited air emissions, increases in ambient noise levels, dust

generation, disturbance of wildlife, increased storm runoff, and disturbance of

recreational and other public facilities. These impacts would be temporary and would

occur only during construction, and are not expected to alter the long-term productivity of

the natural environment.

The Proposed Action would assist in the long-term productivity of the northern

Terrebonne marshes ecological community by improving the water quantity, water

quality, and nutrients delivered to area marshes. This in turn would facilitate the growth

and productivity of emergent marsh habitat. The Proposed Action would also result in

enhancing the long-term productivity of the natural communities throughout the region.

These long-term beneficial effects of the Proposed Action would outweigh the minimal

and mitigable short-term impacts to the environment resulting primarily from project

construction.

5.19 Irreversible and Irretrievable Commitments of Resources

NEPA requires that environmental analysis include identification of “any irreversible and

irretrievable commitments of resources which would be involved in the proposed action

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should it be implemented.” Irreversible and irretrievable resource commitments are

related to the use of nonrenewable resources and the effects that the use of these

resources have on future generations. Irreversible effects primarily result from use or

destruction of a specific resource (e.g., energy and minerals) that cannot be replaced

within a reasonable time frame. Irretrievable resource commitments involve the loss in

value of an affected resource that cannot be restored as a result of the action (e.g.,

extinction of a threatened or endangered species or the disturbance of a cultural site).

The proposed project would result in few direct and indirect commitments of resources;

these would be related mainly to construction components. For the proposed alternatives,

most resource commitments are neither irreversible nor irretrievable. Most impacts are

short term and temporary. Others that may have a longer effect can be reduced through

appropriate measures. There is no irreversible or irretrievable commitment of resources

which would preclude formulation or implementation of reasonable alternatives for this

project.

5.20 Mitigation

Project plans and alternatives were developed in accordance with Corps planning

guidance at ER 1105-2-100 which directs that ecosystem restoration projects be designed

to avoid the need for compensatory fish and wildlife mitigation. Formulation of project

alternatives was conducted in compliance with this guidance. Also in accordance with

Corps planning guidance, net ecosystem benefits expected to accrue if the proposed

project is implemented may not be used as wetland banks or mitigation credit by the nonFederal sponsor.

5.21 Cumulative Impacts Summary

The impacts of the Deepwater Horizon oil spill on coastal Louisiana are uncertain at this

time (August 2010). The impacts of the oil spill as well as the various emergency actions

taken to address oil spill impacts (e.g., use of oil dispersants, creation of sand berms, use

of Hesco baskets, rip-rap, sheet piling and other actions) could potentially impact

USACE water resources projects and studies within the Louisiana coastal area, including

the LCA-ARTM project. Potential impacts could include factors such as changes to

existing, future-without, and future-with-project conditions, as well as increased project

costs and implementation delays. The USACE will continue to monitor and closely

coordinate with other Federal and state resource agencies and local sponsors in

determining how to best address any potential problems associated with the oil spill that

may adversely impact project implementation. Supplemental planning and

environmental documentation may be required as information becomes available. If at

any time petroleum or crude oil is discovered on project lands, all efforts will be taken to

seek clean up by the responsible parties, pursuant to the Oil Pollution Act of 1990 (33

U.S.C. 2701 et seq.).

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Table 5.10. Summary of Cumulative Impacts.

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Soils

US: Institutional recognitionof importance of soils withformation of SoilConservation Service later tobecome Natural ResourcesConservation Service.LA: Louisiana coastal landloss of over 1.22 million acressince 1956.SA: Loss of 37,536 acressince 1985

US: Natural processes ofparent material, climate,organisms, relief, and timefactors in soil formation.LA: Continued land loss ofover 25 square miles per year.SA: Continued decline ofland area due to natural andhuman-induced causes.

US & LA: Continuedinstitutional recognition;continued loss of soilresources.SA: Land loss would persistthroughout resulting in theloss of soil resources.Over the 50-year period ofanalysis, there would be aprojected loss of 101,570acres at a rate of 2,031 acresper year.

US & LA: Continued institutional recognition and programsfor soil conservation to reduce soil losses.ALT 2 (NER Plan and RP): This alternative would havepositive synergistic effects on soil resources when combinedwith other Federal, state, local, and private restoration efforts.A net total of 9,655 acres of wetland soils would be protected,created, and nourished.ALT 3: Cumulative impacts similar to ALT 2. A net total of10,308 acres of wetland soils would be protected, created, andnourished.ALT 4: Cumulative impacts similar to ALT 2. A net total of12,204 acres of wetland soils would be protected, created, andnourished.ALT 5: Cumulative impacts similar to ALT 2. A net total of13,934 acres of wetland soils would be protected, created, and

nourished.ALT 6: Cumulative impacts similar to ALT 2. A net total of 7acres of wetland soils would be protected, created, andnourished.ALT 7: Loss of 2,651 acres of wetland soils offset by overallimprovement in health of remaining wetland soils.

ALT 8: Cumulative impacts similar to ALT 2. A net total of989 acres of wetland soils would be protected, created, andnourished.

*Includes Spatial/Geographic Extent (Continental United States [US], Louisiana [LA], and Study Area [SA], and Temporal (Past, Present, and Futurewith the No Action Alternative). This cumulative impact analysis follows the 11-step process described in the 1997 report by the Council of EnvironmentalQuality entitled “Considering Cumulative Effect Under the National Environmental Policy Act.”

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Hydrology – Flowsand Water Levels

US, LA, & SA: Flows andwater levels respond tonatural conditions.

US & LA: Increased flowsand water levels withincreased runoff due toincreasing urbanization andwetland loss. Rate of relativesea level rise increasing overhistoric conditions.SA: Increased flows andwater levels due to build-upof the Atchafalaya Riverdelta, coastal wetland loss,and increased runoff due tourbanization.

US & LA: Increased flowsand water levels withincreased urbanization andassociated runoff andincreased wetland loss. Rateof relative sea level riseincreasing over historicconditions.SA: Increased flows andwater levels due to build-upof the Atchafalaya River deltaand coastal wetland loss, andincreased runoff due tourbanization.

US & LA: Increased flows and water levels withincreased urban runoff from increasing urbanizationand increased wetland loss. Rate of relative sea levelrise increasing over historic conditions.ALT 2 (NER Plan and RP): Increased flowsthroughout the study area due to water controlstructures. Reduced flow in HNC. Flows in GIWWincreased up to 50 percent east of Houma. Stageincreases of 0.1 to 0.3 feet over most of project area.Other projects in the area could increase flows toproject area (e.g. Davis Pond, Small Bayou LafourcheReintroduction, Avoca Island Diversion).ALT 3: Cumulative impacts similar to ALT 2.ALT 4: Cumulative impacts similar to ALT 2, but withincreased flows and stages in the Grand Bayou area dueto pump station.ALT 5: Cumulative impacts similar to ALT 4.ALT 6: Changes in flows would largely be in theGIWW and Grand Bayou. Changes in flows in theGIWW would range from decreases of 5 percent toincreases of 5 percent. Stage increases of up to 0.1 feetin Penchant basin. Stage increases of up to 0.1 feet inGrand Bayou area.ALT 7: Reduced flows in HNC.ALT8: Cumulative impacts similar to ALT 2, but withno stage impacts in western project area.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Hydrology –Sedimentationand Erosion

US: Decreasingsedimentation due toreduction of erosion onland, reservoirs, and bankstabilization.LA & SA: Sedimentdelivery by crevassesended after 1928 floodcontrol act.

US: Decreasingsedimentation due toreduction of erosion onland, reservoirs and bankstabilization.LA & SA: Inflow ofsuspended sediments byMississippi River limitedby construction of levees.Atchafalaya continues tosupply sediment toAtchafalaya and Wax LakeOutlet deltas.

US: Continued decreasingsedimentation due toreduction of erosion onland, reservoirs and bankstabilization.LA: Sediment supply doesnot offset coastal land loss.SA: Sediment supply doesnot offset land loss.

US & LA: Continued decreasing sedimentationdue to reduction of erosion on land, reservoirs andbank stabilization. Continued buildup ofAtchafalaya and Wax Lake Outlet deltas.All ALTs – small increases in amount of

sediments delivered to Study Area due to distancefrom sediment sources.

Water Quality

US, LA, & SA: CWA(1977), NEPA (1969),CZMA and EstuaryProtection Act provideinstitutional recognition torestore and protect waterbodies, especially withrespect to point sources.Non-point sources stillunregulated.

US & LA: Continuedinstitutional recognition.Increasing humanpopulations andindustrialization result inincreased potential forwater quality problems.SA: Wastewater andpolluted runoff from urbanareas enters the SAthrough drainage and tidalaction. Continued loss ofemergent wetlands impactsthe marshes’ ability toabsorb and reduce waterpollutants.

US, LA, & SA: Continuedinstitutional recognition.Increasing humanpopulations andindustrialization result inincreased potential forwater quality problems.

US & LA: Continued institutional recognition.

Increasing human populations andindustrialization result in increased potential forwater quality problemsALT 2 (NER and RP): Increased delivery offreshwater to study area marshes would increasenutrient load in receiving waters. Increasednutrients are anticipated to improve growth ofemergent marsh vegetation but could increasenoxious algal blooms. Reduced loss of marshvegetation would improve study area marshes’ability to absorb and reduce water pollutants.

Secondary erosion and associated sedimentationcould occur. This alternative would have positivesynergistic effects on water quality whencombined with other Federal, state, local, andprivate restoration efforts.

ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Water Quality– Salinity

US, LA, & SA: Increasein salinity levels due tosaltwater intrusion fromsea level rise, subsidence,human alterations, andwetland losses.

US, LA, & SA: Increasesin salinity levels due tosaltwater intrusion fromsea level rise, subsidence,human alterations, andwetland losses.

US, LA, & SA: Increasesin salinity levels due tosaltwater intrusion fromsea level rise, subsidence,human alterations, andwetland losses.

US, LA, & SA: Increases in salinity levels due tosaltwater intrusion from sea level rise, subsidence,human alterations, and wetland losses.ALT 2(NER Plan and RP): Decreases in salinitylevels throughout most of study area. Slightincreases in salinity levels in areas near the HNClock complex. This alternative would have positivesynergistic effects on salinity levels when combinedwith other Federal, state, local, and privaterestoration efforts.ALT 3: Cumulative impacts would be similar toALT 2.ALT 4: Cumulative impacts would be similar toALT2, but decreases in salinity levels in the GrandBayou area would be greater due to the pumpstation.ALT 5: Cumulative impacts would be similar toALT 4.ALT 6: Cumulative impacts would be similar toALT2, but to a lesser degree.ALT 7: Cumulative impacts would be similar toALT 2, but to a lesser degree.ALT 8: Cumulative impacts would be similar toALT2, but to a lesser degree.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Air Quality

US, LA, & SA:Institutional recognitionvia Clean Air Act of 1963.LA & SA: Institutionalrecognition via LouisianaEnvironmental Quality Actof 1983. Formation ofUSEPA and LDEQ.SA: Development ofsurrounding areas.

US, LA, & SA: Continuedinstitutional recognition;deterioration of air qualitydue to increases in humanpopulations and industry,coupled with loss ofwetlands and air filtrationservices they provide.

SA: Continueddevelopment ofsurrounding areas. Studyarea is in attainment.

US, LA, & SA: Continuedinstitutional recognition;air quality would likelydecline due to continuedpopulation growth andincreased industrialization.Loss of LA coastalresources would reduce airfiltration services providedby this resource.

US & LA: Continued institutional recognition;however, air quality would likely decline due tocontinued population growth and increasedindustrialization.ALT 2 (NER Plan and RP): Primary cumulativeimpacts would be the potential improvement inair quality due to the removal of air pollutants byvegetation. This alternative would have positivesynergistic effects on air quality when combinedwith other Federal, state, local, and privaterestoration efforts.ALTs 3, 4, & 5: Cumulative impacts would besimilar to ALT 2, but to a greater degree.ALTs 6, 7, & 8: Cumulative impacts would besimilar to ALT 2, but to a lesser degree.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Noise

US, LA, & SA:Institutional recognitionthrough Noise Control Actof 1972.

US, LA, & SA: Continuedinstitutional recognitionthrough Noise Control Actof 1972. Continuedhuman population growthand development causessome noise pollution.SA: Ambient noise fromboats, airboats and otherhuman activities maycause some minimal andtemporary disturbances inthe study area.

US, LA, & SA: Continuedinstitutional recognition;continued humanpopulation growth anddevelopment cause somenoise pollution.SA: Ambient noise fromboats, airboats and otherhuman activities continueto cause some minimal andtemporary disturbances inthe study area.

US & LA: Continued institutional recognition;continued human population growth anddevelopment would cause some noise pollution.ALT 2 (NER Plan and RP): Localized andtemporary increases in noise pollution associatedwith construction of project features wouldimpact residential properties and fish and wildliferesources. Some residences would experiencenoise levels above 65 dBA.ALTs 3, 6, and 8: Cumulative impacts would be

similar to ALT 2.ALTs 4 & 5: Cumulative impacts would besimilar to ALT 2. Some long-term noisepollution would result from operation of the pumpstation at Grand Bayou.ALT 7: Minimal noise pollution impacts wouldbe associated with this Alternative.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

VegetationResources

US, LA, & SA: NaturalProcesses form coastalvegetation resources.Invasive plant species,intentionally andunintentionally released,displace native vegetationin some habitats.LA: Louisiana coastal landloss of over 1.22 millionacres since 1956.

SA: Loss of 37,536 acressince 1985.

US & LA: Deteriorationand loss of wetlandsnationwide and statewide.Spread of invasive plantspecies.LA: Continued land loss ofover 25 square miles peryear.SA: Continued decline ofland area due to naturaland human-inducedcauses. Land losscontinues to occur in thestudy area at a rate ofapproximately 2,400 acresper year.

US & LA: Continueddeterioration and loss ofvegetated wetland habitatacreage due to natural andhuman-induced processes.Continued spread ofinvasive plant species.

SA: Land loss wouldpersist throughoutresulting in the loss ofvegetation resources.Over the 50-year period ofanalysis, there would be aprojected loss of 92,193acres at a rate of 1,844acres per year.

US & LA: Continued deterioration and loss of vegetatedwetland habitat and further introduction and spread ofinvasive plant species. Wetland protection, creation, andrestoration, as well as invasive species control, reduce thesetrends somewhat.ALT 2 (NER Plan and RP): This alternative would havepositive synergistic effects on vegetation resources whencombined with other Federal, state, local, and privaterestoration efforts. A net total of 9,655 acres of wetlandswould be protected, created, and nourished.ALT 3: Cumulative impacts similar to ALT 2. A net total of10,308 acres of wetlands would be protected, created, andnourished.ALT 4: Cumulative impacts similar to ALT 2. A net total of12,204 acres of wetlands would be protected, created, andnourished.ALT 5: Cumulative impacts similar to ALT 2. A net total of13,934 acres of wetlands would be protected, created, andnourished.ALT 6: Cumulative impacts similar to ALT 2. A net total of7 acres of wetlands would be protected, created, andnourishedALT 7: Loss of 2,651 acres of wetlands offset by overallimprovement in health of remaining wetlands.ALT 8: Cumulative impacts similar to ALT 2. A net total of989 acres of wetlands would be protected, created, andnourished.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Wildlife

US, LA, & SA: Wetlanddependent wildlifepopulations respond primarilyto natural populationregulating mechanisms.

US, LA: Continuednationwide degradation andloss of wetlands leads todecline of wetland-dependentwildlife populations.SA: Continued wetlanddegradation and loss leads toincreased competitionbetween local wetlanddependent wildlifepopulations for decreasingresources; displacement toother more suitable wetlandareas; and localized decline inwetland-dependent wildlifepopulations.

US, LA: Nationwidedegradation and loss ofwetlands continues toadversely impact wetlanddependent wildlifepopulations.SA: An expected 92,193acres of wetlands lost fromthe study area at a rate of1,844 acres per year over thenext 50 years. Leads toincreased competitionbetween local wetlanddependent wildlifepopulations for decreasingresources; displacement toother more suitable wetlandareas; and localized decline inwetland-dependent wildlifepopulations.

US, LA: Continued nationwide loss of vegetatedwetlands continues to adversely impact wetlanddependent wildlife populations.ALT 2 (NER Plan and RP): This alternative wouldhave positive synergistic effects on wildlife resourceswhen combined with other Federal, state, local, andprivate restoration efforts. A net total of 9,655 acres ofwetlands would be protected, created, and nourished.Improvement in habitat would lead to increased habitatfor wetland-dependent wildlife; decreased competitionfor resources; and localized stabilization orimprovement in wetland-dependent wildlifepopulations.ALT 3: Cumulative impacts similar to ALT 2. A nettotal of 10,308 acres of wetlands would be protected,created, and nourished.ALT 4: Cumulative impacts similar to ALT 2. A nettotal of 12,204 acres of wetlands would be protected,created, and nourished.ALT 5: Cumulative impacts similar to ALT 2. A nettotal of 13,934 acres of wetlands would be protected,created, and nourished.ALT 6: Cumulative impacts similar to ALT 2. A nettotal of 7 acres of wetlands would be protected, created,and nourished.ALT 7: Loss of 2,651 acres of wetlands offset byoverall improvement in remaining wetlands.ALT 8: Cumulative impacts similar to ALT 2. A nettotal of 989 acres of wetlands would be protected,created, and nourished.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Fisheries

US & LA: Reduction infisheries habitat whilecatches increased.Formation of the NationalMarine Fisheries Service.SA: Reduction insustainability of fisherieshabitat, while access(marsh edge) increased;increased productivity andcatch.

US & LA: Regulatedcatch; habitat lossdecreased somewhat bycoastal restoration efforts;continued net habitat loss.SA: Fishery populationchanges associated withthe distribution andstructure of coastal marshvegetative communities,which are shallow-water

habitat for migratory andresident estuarine-marine

species of fish.

US, LA, & SA: Continuedloss of fishery resourcesunless intensified efforts toprotect them locally,statewide, and nationally.High level of fisheryproductivity may beunsustainable asmarsh/water interfacedeclines.

US & LA: Continued loss of fishery resourcesunless intensified efforts taken to protect them,locally, statewide, and nationally.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects onfisheries resources when combined with otherFederal, state, local, and private restorationefforts. Marsh habitat protected by thisalternative would serve as important and essentialtransitional wetland habitats used by fisheryresources for spawning, foraging, cover, nursery,and other life requirements. Some shifts indistribution of fisheries would occur due tochanges in salinities.ALT 3: Cumulative impacts similar to ALT 2.ALTs 4 & 5: Cumulative impacts similar to ALT2. More dramatic shift in distribution of fisherieswould occur in Grand Bayou area due to changesin salinities associated with pump station.ALTs 6, 7, & 8: Cumulative impacts similar toALT 2, but to a lesser degree. ALT 7:Cumulative impacts similar to ALT 3, but to alesser degree.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

AquaticResources –Plankton

US, LA, & SA:Populations respond tonatural conditions.

US: Populations respondto natural and humaninduced perturbations.LA & SA: Populations inportions of the state and inthe study area are shiftingtowards more salinedominant species as landloss and saltwater intrusioninto interior regionscontinue.

US: Populations continueto respond to natural andhuman-inducedperturbations.LA & SA: Increased landloss and saltwater intrusionwould lead to more salineadapted populations.

US & LA: Plankton populations continue to respond tonatural and human-induced perturbations.ALT 2 (NER Plan and RP): This alternative wouldhave positive synergistic effects on plankton resourceswhen combined with other Federal, state, local, andprivate restoration efforts. Wetland protection, creationand nourishment would result in greater resources forphytoplankton and zooplankton due to export ofdissolved organic compounds and detritus fromwetlands. Negative synergistic effects from increasedflows and nutrients could result in an increase innoxious algal blooms.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impacts would besimilar to ALT 2..

AquaticResources –Benthic

US, LA, & SA:Populations respond tonatural conditions.

US: Populations respondto natural and humaninduced perturbations.LA & SA: Populations inportions of the state and inthe study area are shiftingtowards more salinedominant species as landloss and saltwater intrusioninto interior regionscontinue.

US: Populations continueto respond to natural andhuman-inducedperturbations.LA & SA: Increased landloss and saltwater intrusionwould lead to more salineadapted populations.

US & LA: Plankton populations continue to respond tonatural and human-induced perturbations.ALT 2 (NER Plan and RP): This alternative wouldhave positive synergistic effects on benthic resourceswhen combined with other Federal, state, local, andprivate restoration efforts. Wetland protection, creationand nourishment would result in greater resources forbenthic organisms due to export of dissolved organiccompounds and detritus from wetlands. Increasedfreshwater flows would be expected to shift the benthiccommunity, displacing marine species in favor offresher and more estuarine, euryhaline species.ALTs, 3, 4, 5, 6, 7, & 8: Cumulative impacts would besimilar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Essential FishHabitat

US, LA, & SA: Generaldecrease in quality of EFHbeginning in the mid1900s. Institutionalrecognition of decline inEFH quality; passage ofMagnuson-Stevens FisheryConservation andManagement Act.

US & LA: Continuedinstitutional recognition;continued wetland loss anddecline in quality of EFH.SA: Continued wetlandloss converts high qualityEFH to lower qualitycategories (e.g., emergentwetlands to open waterbottoms).

US & LA: Continuedinstitutional recognition;continued wetland loss anddecline in quality of EFH.SA: Continued wetlandloss converts high qualityEFH to lower qualitycategories (e.g., emergentwetlands to open waterbottoms).

US & LA: Continued institutional recognition;continued overall decline in quality of EFHmaking it difficult to maintain productive formsof EFH and ability of US to support Federallymanaged species.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects on EFHwhen combined with other Federal, state, local,and private restoration efforts. Wetlandprotection, creation and nourishment wouldprevent the conversion of transitional wetlands toopen water, especially inner marsh and marshedge, which provide EFH for brown shrimp,white shrimp, red drum, and Gulf stone crab.Organism access to EFH would be impeded bysome project features.

ALTs 3, 4, & 5: Cumulative impacts would besimilar to ALT 2, but to a greater degree.ALTs 6, 7, & 8: Cumulative impacts would be

similar to ALT 2, but to a lesser degree.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Threatened andEndangeredSpecies

US: Institutionalrecognition of decline inlisted species via theEndangered Species Act.LA & SA: Decrease insome animal and plantpopulations and theircritical habitat includingloss of wetlands.

US: Continuedinstitutional recognition ofdecline in listed species;continued wetland loss.LA & SA: Continued lossof wetlands that are criticalhabitat to many listedspecies.

US: Continuedinstitutional recognition ofdecline in listed species;continued loss of wetlands.LA & SA: Continuedcoastal land loss anddeterioration of criticalcoastal habitats isanticipated to impact alllisted species that utilizethem.

US & LA: Continued institutional recognition ofdecline in listed species; continued loss ofwetlands.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects on listedspecies when combined with other Federal, state,local, and private restoration efforts. ALT 2 isnot likely to adversely affect any threatened orendangered species in the project area.ALTs, 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

Cultural andHistoricResources

US, LA, & SA:Institutional Recognitionvia National HistoricPreservation Act (andothers). Historic andcultural resourcessubjected to naturalprocesses and manmadeactions.

US, LA, & SA:Continued institutionalrecognition. Humanactivities as well as naturalprocesses can potentiallydegrade or destroy historicand cultural resources.

US, LA, & SA: Continuedinstitutional recognition.Potential loss of resourcesdue to natural and humancauses.

US & LA: Potential loss of resources due tonatural and human causes.ALT 2 (NER Plan and RP): Prevention of furtherland loss and erosion in the project area wouldhelp protect cultural and historical resources inthe long term. Phase I testing and/or monitoringwill be conducted to determine potential directimpacts of project features on cultural and historicresources.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Aesthetics

US, LA, & SA: Technicalrecognition via 1988USACE Visual ResourcesAssessment Procedure.Institutional recognitionvia Wild and ScenicRivers Act, ScenicByways and others.LA & SA: Visualaesthetics shaped byhuman activities (e.g.,development and floodcontrol) and naturalalterations (e.g.,hurricanes) to thelandscape.

US, LA, & SA: Continuedinstitutional recognition.Visual resources have beendestroyed, enhanced, orpreserved by humanactivities and naturalprocesses.LA & SA: Continuedwetland loss may have anadverse effect on thevisual complexity of thecoastal resources.

US, LA, & SA: Continuedinstitutional recognition.Continued humanpopulation growth anddevelopment and otherhuman activities have thepotential to destroy,enhance, or preserve visualresources.SA: Continued marshdegradation coulddiminish the value of theviewscape.

US & LA: Continued human population growthand development and other human activities havethe potential to destroy, enhance or preservevisual resources.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects onaesthetics when combined with other Federal,state, local, and private restoration efforts.Implementation of the project would provide amore contiguous marsh, which would protectdesirable viewscapes.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

Recreation

US, LA, & SA: Publiclands institutionallyrecognized by FederalWater Project RecreationAct, Land and WaterConservation Act, andNational Wildlife RefugeSystem Acts.SA: Recreation activitiesin study area based onecosystem services.

US & LA: Continuedinstitutional recognition.Increased recreationalactivities impact nationaland state wetlands.SA: Recreation activitiesin study area based onecosystem services.Ecosystem degradationimpedes ability to providesome services at historicallevels.

US, LA, & SA: Continuedinstitutional recognition.Potential inability toprovide ecosystemservices to supportrecreation due todegradation and loss ofcoastal marshes.

US & LA: Loss of recreational resources due tocontinued wetland and coastal degradation.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects onrecreation resources when combined with otherFederal, state, local, and private restorationefforts. The proposed action would preservenatural habitats, and thereby enable thecontinuation of existing recreational activitieswithin the study area.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Displacement ofPopulation andHousing

US: Population increasingin some areas anddecreasing in others.LA: Hurricanes Katrinaand Rita adversely affectedpopulations throughoutstate.SA: Development alongridges and water bodies.Populations withinLafourche and TerrebonneParishes increasing.Population in St. MaryParish decreasing since1980.

US: Increasing populationwith over 300 millionpeople.LA: Slight decrease(3.9%) in population from2000-2007.SA: Populations inLafourche and TerrebonneParishes increasing.Population in St. MaryParish decreasing slowly.

US & LA: Increasingpopulations worldwide.SA: Populations inLafourche and TerrebonneParishes projected toincrease. Population in St.Mary Parish projected todecrease slowly.Populations would beadversely impacted bycontinued habitatdegradation.

US & LA: Continued wetland and coastaldegradation could lead to population shifts.Population growth expected.ALT 2 (NER Plan and RP): Positive synergisticeffects on population and housing whencombined with other Federal, state, local, andprivate restoration efforts could be realized asimprovements to coastal resources slowpopulation shift away from coast. Acquisition ofrights-of-way and relocation of residential

structures would be required for construction ofsome project features.ALTs 3, 4, 5, 6, & 8: Cumulative impacts would

be similar to ALT 2.ALT 7: Cumulative impacts would be similar toALT 2. However, no rights-of-way or relocations

would be required.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Employmentand Income,Business andIndustry

US & LA: Increasedhabitation, employmentand tourism.LA: Slight increase inemployment in Louisiana.Hurricanes Katrina andRita have an adverse effecton employment andpersonal income.Rebuilding efforts providesome new jobopportunities.SA: Development alongridges and water bodies.Employment and incomeprovided through oil andgas production,manufacturing,transportation, agriculture,commercial fishing, etc.

US, LA, & SA: Increasingpopulation growth andemployment and personalincome opportunities.Business and industryrelated to wetlandresources negativelyaffected by loss of theseresources.

US, LA, & SA: Increasingpopulation growth andemployment and incomeopportunities. Businessand industry related towetland resources wouldbe adversely affected bythe degradation and loss ofthese resources.

US & LA: Continued wetland degradation wouldadversely impact economic activities tied to fishand wildlife found within the natural wetlandhabitats.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects onemployment and income and business andindustry when combined with other Federal, state,local, and private restoration efforts. Protectionof coastal marsh habitat would benefit localemployment in wetland-dependent jobs such ascommercial fishing and would protect oil and gasinfrastructure in the study area. Wave and stormsurge buffering capacity of marshes would helpprotect business and industry behind levees.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Transportation

US & LA: Increasingpopulation growthincreases demand on thetransportation network.SA: Transportation routesfollow natural high ridges.US 90 and four statehighways run through theproject area.

US & LA: Increasingpopulation growthincreases demand on thetransportation network.SA: Transportation routesfollow natural high ridges.US 90 and four statehighways run through theproject area.

US & LA: Continuedpopulation growthincreases demand on thetransportation network.SA: Major transportationroutes not likely to change.Roads on distributaryridges may become morevulnerable as subsidenceand marsh loss continue.

US & LA: Continued population growth increasesdemand on the transportation network.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects ontransportation when combined with other Federal,state, local, and private restoration efforts. Waveand storm surge buffering capacity of marsheswould provide some added protection tovulnerable transportation routes. Construction ofproject features would contribute to trafficcongestion and delays on area roads.ALTs 3, 4, 5, 6, & 8: Cumulative impacts wouldbe similar to ALT 2.ALT 7: Cumulative impacts would be similar toALT 2. However, no construction-related trafficimpacts would occur.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Public Facilitiesand Services

US & LA: Increasingpopulation growthincreases demand onpublic facilities andservices.SA: Schools, hospitals,police and fire protection,levees and pump stationsexpand to accommodateincreasing residentialpopulation.

US & LA: Increasingpopulation growthincreases demand onpublic facilities andservices.SA: Public facilities andservices continue to serveresidential population.

US & LA: Increasingpopulation growthincreases demand onpublic facilities andservices.SA: Public facilities andservices continue to serveresidential population.

US & LA: Continued population growth increasesdemand on public facilities and services.

All ALTs: No impacts to public facilities andservices are anticipated.

Socioeconomicand HumanResources –Tax Revenuesand PropertyValues

US, LA, & SA: Increasingpopulation growthincreases tax revenue andproperty values.

US, LA, & SA: Increasingpopulation growthincreases tax revenue andproperty values.Continued degradation ofcoastal marshes reducestax revenues and propertyvalues in areas beingvacated.

US, LA, & SA: Increasingpopulation growthincreases tax revenue andproperty values.Continued degradation ofcoastal marshes reducestax revenues and propertyvalues in areas beingvacated.

US & LA: Increasing population growthincreases tax revenue and property values.Continued degradation of coastal marshes reducestax revenues and property values in areas beingvacated.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects on taxrevenues and property values when combinedwith other Federal, state, local, and privaterestoration efforts. Reducing the rate of land lossin the project area would be expected to decreasethe rate at which residents and businesses leavethe area.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Communityand RegionalGrowth(IncludingCommunityCohesion)

US: Increasing populationleads to greater communityand regional growth.Community cohesion isaffected by communityand infrastructuredevelopment.LA & SA: Increasingpopulation increasescommunity and regionalgrowth. HurricanesKatrina and Rita adverselyaffected communitycohesion in southernportions of the state.Community cohesion isaffected by infrastructuredevelopment. Populationswithin Lafourche andTerrebonne Parishesincreasing. Population inSt. Mary Parish decreasingsince 1980.

US: Increasing populationleads to greater communityand regional growth.Community cohesion isaffected by communityand infrastructuredevelopment.LA & SA: Increasingpopulation increasescommunity and regionalgrowth. HurricanesKatrina and Rita adverselyaffected communitycohesion in southernportions of the state.Community cohesion isaffected by infrastructuredevelopment. Populationsin Lafourche andTerrebonne Parishesincreasing. Population inSt. Mary Parish decreasingslowly.

US & LA: Increasingpopulation leads to greatercommunity and regionalgrowth. Communitycohesion would continueto be affected byinfrastructure andcommunity development.Community cohesion insouthern portions of thestate would continue to beaffected by threat oftropical storms andhurricanes.SA: Populations inLafourche and TerrebonneParishes projected toincrease. Population in St.Mary Parish projected todecrease slowly.Community cohesionwould continue to beaffected by threat oftropical storms andhurricanes.

US & LA: Increasing population leads to greatercommunity and regional growth. Communitycohesion would continue to be affected byinfrastructure and community development.Community cohesion in southern portions of thestate would continue to be affected by threat oftropical storms and hurricanes.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects oncommunity and regional growth and communitycohesion when combined with other Federal,state, local, and private restoration efforts.Reducing the rate of land loss in the project areawould be expected to decrease the rate at whichresidents leave the area.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –EnvironmentalJustice

US: Institutionalrecognition via ExecutiveOrder 12898.LA: In 2000, 38.7 percentminority population; 19.6percent low-incomepopulation.SA: In 2000, TerrebonneParish minority population27.9 percent; low-incomepopulation 19.1 percent;Lafourche Parish minoritypopulation 18.8 percent;low-income population16.5 percent.

US & LA: Continuedinstitutional recognition.SA: In 2008, TerrebonneParish minority population30.2 percent; low-incomepopulation 16.5 percent;Lafourche Parish minoritypopulation 20.5 percent;low-income population16.5 percent.

US & LA: Continuedinstitutional recognition.SA: Minority and lowincome populationsexpected to remain nearcurrent levels.

US & LA: Continued institutional recognition.

All ALTs: No disproportionately high or adversehuman health or environmental effects onminority or low-income populations in the study

area are anticipated.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Water Use andSupply

US, LA, & SA:Institutional recognition(Clean Water Act andothers); saltwater intrusioninto historically freshwater areas; industrialpollution of waters;changes to hydrology bylevees affect water supplyto wetlands.SA: Designated useswithin study area includeprimary contact recreation,secondary contactrecreation, fish andwildlife propagation,drinking water supply,oyster propagation,agriculture, andoutstanding naturalresource waters.

US, LA, & SA: Continuedinstitutional recognition;saltwater intrusion intohistorically fresh waterareas; industrial pollutionof waters; changes tohydrology by levees affectwater supply to wetlands.SA: Designated useswithin study area includeprimary contact recreation,secondary contactrecreation, fish andwildlife propagation,drinking water supply,oyster propagation,agriculture, andoutstanding naturalresource waters. Periodicsaltwater intrusion inBayou Lafourche andGIWW affects drinkingwater supply.

US, LA, & SA: Continuedinstitutional recognition;saltwater intrusion intohistorically fresh waterareas; industrial pollutionof waters; changes tohydrology by levees affectwater supply to wetlands.SA: Existing designateduses within study areawould continue. Saltwaterintrusion would continue.

US: Continued institutional recognition;continued saltwater intrusion; continued industrialpollution; continued changes to hydrology thataffect water supply to wetlands.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects on wateruse and supply when combined with otherFederal, state, local, and private restorationefforts. Reducing the rate of land loss in theproject area would be expected to reducesaltwater intrusion. Saltwater intrusion in BayouLafourche could increase.ALTs 3, 6, 7, & 8: Cumulative impacts would besimilar to ALT 2.ALTs 4 & 5: Cumulative impacts would besimilar to ALT 2. However, saltwater intrusion inBayou Lafourche would be greater.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Navigation

US, LA, & SA:Navigation interests havehistorically been a criticalfactor to national, state,and local interests.Growth of port facilitiesand inland waterways andtraffic.LA & SA: HurricanesKatrina and Rita impactnavigation infrastructureand investments. Publicand private reinvestment torebuild navigation, portfacilities, and inlandwaterways.SA: Navigationestablished on GIWW,Lower Atchafalaya River,Bayous Chene, Boeuf, andBlack, Houma NavigationCanal, and otherwaterways in study area.

US, LA, & SA: Continuedinvestment in portfacilities and inlandwaterways. Navigationcontinues to be animportant part of nationaltransportation andcommerce activities.Navigation negativelyimpacted by coastal marshloss as navigation channelsbecome more exposed towind, weather, and waves.

US, LA, & SA: Continuedinvestment in portfacilities and inlandwaterways. Navigationcontinues to be animportant part of nationaltransportation andcommerce activities.Navigation negativelyimpacted by coastal marshloss as navigation channelsbecome more exposed towind, weather, and waves.

US & LA: Continued investment in port facilitiesand inland waterways. Navigation continues tobe an important part of national transportation andcommerce activities. Navigation would continueto be negatively impacted by coastal marsh lossas navigation channels become more exposed towind, weather, and waves.ALT 2 (NER Plan and RP): This alternative

would negatively impact navigation on theHouma Navigation Canal by delaying traffic thatis forced to use the lock. Vessels would bedelayed, on average, eighteen minutes.Navigation would also be negatively impacted onother water bodies by placement of plugs andweirs that would prevent navigation or limit it tovessels under a certain size. Some secondaryerosion could also occur along channels receivingincreased flows, causing localized shoaling. Thisalternative would also have positive synergisticeffects on navigation when combined with otherFederal, state, local, and private restorationefforts. Reducing the rate of land loss in theproject area would be expected to benefitnavigation channels as they would be lessexposed to wind, weather, and waves.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impactswould be similar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Agriculture

US & LA: Agriculture isimportant to the economyof the US and coastalLouisiana.LA: Important cropsinclude sugar cane, rice,and soybeans.SA: Agricultureconcentrates alongdistributary ridges. Majorcrop is sugarcane. Majorlivestock includescrawfish, alligators, cattle,and horses.

US & LA: Agriculture isimportant to the economyof the US and coastalLouisiana.LA: Important cropsinclude sugar cane, rice,and soybeans. Agriculturethreatened by land loss andsaltwater intrusion.SA: Agricultureconcentrated alongdistributary ridges. Majorcrop is sugarcane. Majorlivestock includescrawfish, alligators, cattle,and horses. Agriculturethreatened by land loss andsaltwater intrusion.

US & LA: Agricultureexpected to remainimportant to the economyof the US and coastalLouisiana.LA: Important cropswould continue to be sugarcane, rice, and soybeans.Agriculture wouldcontinue to be threatenedby land loss and saltwaterintrusion.SA: Major crop expectedto remain sugarcane.Major livestock expectedto remain crawfish,alligators, cattle, andhorses. Agriculture wouldcontinue to be threatenedby land loss and saltwaterintrusion.

US & LA: Continued importance of agriculture tothe economy of the US and coastal Louisiana.Agricultural lands would continue to be adverselyimpacted by land loss and saltwater intrusion.

ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects onagriculture when combined with other Federal,state, local, and private restoration efforts.Reducing the rate of land loss in the project areawould be expected to benefit levees protectingagriculture lands by reducing exposure to wavedamage.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impacts

would be similar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Forestry

US & LA: Timberproduction is important tothe economy of the US andLouisiana. Institutionalrecognition via regulationson forest harvest practices.SA: Limited timberproduction in Lafourche,St. Mary, and TerrebonneParishes.

US: Continuedinstitutional recognition;however, increasinghuman populations resultin continued loss offorested areas and reducesforestry opportunities.LA: Continuedinstitutional recognition.Continued coastal landloss reduces forestryopportunities.SA: Limited timberproduction in Lafourche,St. Mary, and TerrebonneParishes.

US: Continuedinstitutional recognition;increasing humanpopulation growth andcontinued demand fordiminishing forestryresources and reducedforestry opportunities.LA: Continuedinstitutional recognition.Continued coastal landloss reduces forestryopportunities.SA: Continued limitedtimber production inLafourche, St. Mary, andTerrebonne Parishes.

US & LA: Continued institutional recognition;increasing human population growth andcontinued demand for diminishing forestryresources and reduced forestry opportunities.

ALT 2 (NER Plan and RP): This alternativewould have some positive synergistic effects onforestry when combined with other Federal, state,local, and private restoration efforts. Reducingthe rate of land loss in the project area would beexpected to benefit levees protecting limitedforestry lands by reducing exposure to wavedamage.ALTs 3, 4, 5, 6, 7, & 8: Cumulative impacts

would be similar to ALT 2.

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Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Public Lands

US & LA: Institutionalrecognition through theFederal Water ProjectRecreation Act of 1965;the Land and WaterConservation Fund Act of1965; the NationalWildlife Refuge SystemAdministration Act of1966; the NationalWildlife Refuge SystemImprovement Act of 1997,and others; creation ofNational Forest Service,National Park Service, USFish &Wildlife Service,Bureau of LandManagement, and others.Expansion of the federalpublic land system.LA: Designation since1959 of nearly 462,000acres as state WildlifeManagement Areas,managed by LDWF.SA: 33, 488-acre Point auChien WildlifeManagement Areaestablished by LDWF in1968; 4,212-acreMandalay NationalWildlife Refugeestablished by FWS in

US & LA: Continuedinstitutional recognitionand expansion of thefederal public land system.LA: Continuedmanagement and growthof state-owned publiclands. Public landsthreatened by land loss.SA: Continuedmanagement of Point auChien WMA andMandalay NWR. Point auChien WMA experiencingland loss at the rate of over1 percent per year.Mandalay NWR generallystable.

US & LA: Continuedinstitutional recognitionand expansion of thefederal public land system.LA: Continuedmanagement and growthof state-owned publiclands. Public landsthreatened by land loss.SA: Continuedmanagement of Point auChien WMA andMandalay NWR. Point auChien WMA expected tocontinue experiencing landloss at the rate of up to 2percent per year.Mandalay NWR expectedto remain stable.

US & LA: Continued institutional recognition andexpansion of the federal public land system.Public lands threatened by land loss.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects on publiclands when combined with other Federal, state,local, and private restoration efforts. Thisalternative is expected to reduce the rate of landloss in the Point au Chien WMA. No impacts toMandalay NWR are expected.ALTs 3, 6, & 8: Cumulative impacts would besimilar to ALT 2.ALTs 4 & 5: Cumulative impacts would besimilar to ALT 2, but to a greater degree.ALT 7: This alternative would be expected tohave a slightly negative impact on land loss ratesin the Point au Chien WMA.

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1996.

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Oil, Gas, andUtilities

US & SA: Increasingdevelopment of refineries,wells, pipelines, and otheroil and gas infrastructureand equipment. Extensiveoil and gas exploration.

US, LA, & SA: Increasingoperations andmaintenance costs as wellas increasing investmentfor oil and gas productionfacilities and pipelines dueto increasing vulnerabilityto widespread coastalwetland loss.

US, LA, & SA: Increasingoperations andmaintenance costs as wellas increasing investmentfor oil and gas productionfacilities and pipelines dueto increasing vulnerabilityto widespread coastalwetland loss.

US & LA: Increasing operations andmaintenance costs as well as increasinginvestment for oil and gas production facilitiesand pipelines due to increasing vulnerability towidespread coastal wetland loss.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects on oil,gas, and utilities when combined with otherFederal, state, local, and private restorationefforts. This alternative is expected to reduce therate of land loss in the study area, therebyreducing the vulnerability of oil, gas, and utilityinfrastructure.

ALTs 3, 4, & 5: Cumulative impacts would besimilar to ALT 2, but to a greater degree.ALTs 6, 7, & 8: Cumulative impacts would be

similar to ALT 2, but to a lesser degree.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Flood Controland HurricaneProtection

US & LA: Flood of 1927initiates nationalconstruction of hurricaneand flood control levees,pump stations and controlstructures. HurricanesKatrina and Rita causesignificant widespreaddamages to existinghurricane and flood controlstructures.SA: Construction of floodcontrol and hurricaneprotection levees in andaround the study areaincluding the WestAtchafalaya BasinProtection Levee, the EastAtchafalaya BasinProtection Levee, theLarose to Golden MeadowHurricane ProtectionLevee, and many locallevees.

US & LA: Largestnational restoration effortof hurricane and floodcontrol in nation’s history.SA: Maintenance of floodcontrol and hurricaneprotection levees in thestudy area.

US & LA: As populationscontinue to migrate tocoastal communities,increasing investment inhurricane and flood controllevees, pump stations, andother flood controlfacilities is expected.SA: Continuedmaintenance of Federaland local flood control andhurricane protectionlevees. Continueddegradation of wetlandswould result in localizedstorm surge and stormwave increases. TheMorganza to the Gulf ofMexico Risk ReductionProject is expected to beconstructed.

US & LA: Continued loss of flood control andhurricane protection due to continued coastalwetland degradation and loss.ALT 2 (NER Plan and RP) : This alternative

would have positive synergistic effects on floodcontrol and hurricane protection when combinedwith other Federal, state, local, and privaterestoration efforts. This alternative is expected toreduce the rate of land loss in the study area,thereby reducing the vulnerability of existingflood control and hurricane protectioninfrastructure to storm surge and wave damage.ALTs 3, 4, & 5: Cumulative impacts would besimilar to ALT 2, but to a greater degree.ALTs 6, 7, & 8: Cumulative impacts would be

similar to ALT 2, but to a lesser degree.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –CommercialFisheries

US, LA, & SA: Formationof the National MarineFisheries Service.Increases in commercialfisheries industry due toadvancing technologiesand increased fishingpressure.

US, LA, & SA:Institutional recognitionand regulation ofcommercial fisheriesmaintains a billion dollarindustry. About 90% ofthe world's seafoodresources have beendepleted in the pastcentury; 38% of thedepleted species havedeclined by more than 90percent; 7% of the speciesof fish studied byresearchers have becomeextinct (Worm et al. 2006).SA: Study area providesessential and criticalhabitat for importantcommercial fisheries.

US, LA, & SA:Institutional recognitioncontinues; changes infishing technology,pressure, and regulationsmay or may not offset anexpected decline incommercial fisheries dueto overfishing and habitatdegradation.

US & LA: Institutional recognition continues;changes in fishing technology, pressure, andregulations may or may not offset an expecteddecline in commercial fisheries due to overfishingand habitat degradation.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects oncommercial fisheries when combined with otherFederal, state, local, and private restorationefforts. This alternative is expected to reduce therate of land loss in the study area, therebybenefitting commercially important fish species.ALTs 3, 4, & 5: Cumulative impacts would besimilar to ALT 2, but to a greater degree.ALTs 6, 7, & 8: Cumulative impacts would besimilar to ALT 2, but to a lesser degree.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Socioeconomicand HumanResources –Oyster Leases

US, LA: General increasein acreage leased,production limited bysaltwater intrusion in areaswith no freshwaterintroduction.SA: Extensive oyster

leases in the study area.Terrebonne and LafourcheParishes account for57,000 acres in the 1970sand early 1980s.

US, LA, & SA: Onlymajor leasing program isin LA. Production hasbeen stable for the last 50years. Long-termsustainability threatenedby reduction of marshhabitat.SA: Extensive oysterleases in the study area.Terrebonne and LafourcheParishes account forapproximately 115,000acres.

US: Only major leasingprogram is in LA.LA & SA: Productionfrom leases would likelydecline due to loss ofhabitat.

US: Only major leasing program is in LA.LA: Production from leases would likely declinedue to loss of habitat.ALT 2 (NER Plan and RP): This alternativewould have positive synergistic effects on oysterleases when combined with other Federal, state,local, and private restoration efforts. Thisalternative is expected to reduce the rate of marshloss in the study area, thereby benefitting oystersand oyster leases. Some oyster leases would bedirectly impacted by construction of projectfeatures. Changes in salinity gradients may affectmortality, reproduction, and spat settlement ofoysters.ALTs 3, 4, & 5: Cumulative impacts would be

similar to ALT 2, but to a greater degree.

ALTs 6, 7, & 8: Cumulative impacts would besimilar to ALT 2, but to a lesser degree.

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Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

No Action

Alternative

(Future Without

Project)

Cumulative Impacts

(Comparison of Future with Proposed

Action Impacts)

Hazardous,Toxic, andRadioactiveWaste

US, LA, & SA:Institutional recognitionunder ER 1165-2-132.Increasing humanpopulations andindustrialization result inincreased potential forHTRW problems.Establishment of USEPAand LDEQ.SA: Few RecognizedEnvironmental Conditions(RECs) located nearproposed project features.No RECs immediatelyadjacent to projectfeatures.

US, LA, & SA: Continuedinstitutional recognition.SA: Few RECs locatednear proposed projectfeatures. No RECsimmediately adjacent toproject features.

US, LA, & SA: Continuedinstitutional recognition.Continued humanpopulation growth &development, industry, andother human activitiesresult in increasedpotential for HTRWissues.

US & LA: Continued institutional recognition.Continued human population growth &development, industry, and other human activitiesresult in increased potential for HTRW issues.All ALTs: The potential for HTRW impacts isexpected to be low.

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6.0 PUBLIC INVOLVEMENT

6.1 NEPA Scoping

The National Environmental Policy Act (NEPA) of 1969 established a nationwide policy

to include a detailed statement of the environmental impact of the proposed action in

every recommendation or report on proposals for major Federal actions significantly

affecting the environment. Such detailed statements are referred to as environmental

impact statements (EIS).

A notice of intent (NOI) to prepare a draft EIS for the Louisiana Coastal Area (LCA)

Convey Atchafalaya River Water to Northern Terrebonne Marshes Restoration

Feasibility Study (Convey Atchafalaya River Water to Northern Terrebonne Marshes

Study) was published in the Federal Register (volume 73, number 246) on December 22,

2008.

The intent of the NOI is to announce the United States Corps of Engineers’ (Corps)

intention to prepare a draft EIS that addresses the Convey Atchafalaya River Water to

Northern Terrebonne Marshes restoration project, which was identified in the LCA

Ecosystem Restoration Plan as a near-term critical restoration project.

The NEPA also provides for an early and open public process for determining the scope

of issues, resources, impacts, and alternatives to be addressed in an EIS. This process is

referred to as scoping. Scoping documents comments from interested parties and

describes where in the EIS individual comments should be addressed. It also outlines the

project background and scoping process to date, and summarizes the key issues identified

by members of the public during the initial scoping period.

NEPA affords all persons, organizations and government agencies the right to review and

comment on proposed major Federal actions that are evaluated by a NEPA document.

This is known as the “scoping process.” The scoping process is the initial step in the

preparation of the EIS and will help identify (1) the range of actions (project, procedural

changes) (2) alternatives (both those to be rigorously explored and evaluated and those

that may be eliminated), and (3) the range of environmental resources considered in the

evaluation of environmental impacts.

A scoping meeting announcement requesting comments regarding the scope of the

Convey Atchafalaya River Water to Northern Terrebonne Marshes Study was sent to

Federal, state, and local agencies; and interested groups and individuals on January 7,

2009. The media advisory announcing the scoping meetings was provided to more than

350 media outlets. An advertisement for the public scoping meetings appeared in the

following publications:

• The Times-Picayune, January 31, 2009

• The St. Bernard Voice, January 30, 2009

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• The Baton Rouge Advocate, January 31, 2009

• Morgan City Daily Review, January 29, 2009

The public scoping meetings were held on:

• Tuesday, February 3, 2009

Houma Municipal Auditorium

880 Verrett St.

Houma, LA 70360

• Wednesday, February 4, 2009

Morgan City Municipal Auditorium

728 Myrtle St.

Morgan City, LA 70380

The schedule for each scoping meeting was:

• 6:00 – 7:00 p.m. Open House

• 7:00 – 7:30 p.m. Presentations

• 7:30 – 8:00 p.m. Question and Answer Session

• 8:00 – 8:50 p.m. Open Forum for Comments

• 8:50 – 9:00 p.m. Wrap-up

The open house session provided attendees with an opportunity to visit a series of poster

stations staffed by project team members and subject matter experts regarding the

following topics: the LCA plan, the NEPA process and milestones, an overview of the

study and its goals and objectives, as well as maps of the study area.

Following the open house, there was a brief presentation on the LCA project planned for

the area and a description of the NEPA process. During this segment, the LCA

Environmental Manager and both the Corps and Coastal Protection and Restoration

Authority Project Managers presented introductory remarks, including the agenda,

purpose of the meeting, public involvement under NEPA, a brief history leading to the

study, the scope of the analysis, and the intent to prepare a draft EIS for the Convey

Atchafalaya River Water to Northern Terrebonne Marshes restoration project.

The question and answer portion focused on the study process and any other general

questions presented by attendees. Following this portion, the floor was opened for

scoping comments. Individuals were invited to present their verbal scoping comments to

be recorded without interruption. The floor remained open until no further scoping

comments were given.

During the wrap-up, attendees were reminded to pick up self mailing comment cards,

should they wish to submit additional comments at a later date, and to drop off the

meeting evaluation forms at the registration table.

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Transcripts of comments made at the scoping meetings were prepared by a court reporter.

The Scoping Report presents and summarizes the scoping comments expressed at the

public scoping meetings, as well as all other scoping comments received during the

comment period beginning December 22, 2008, and ending February 17, 2009. The

Scoping Report is being published on the Louisiana Coastal Area Ecosystem Restoration

website at www.lca.gov Web site.

Scoping comments document the public’s concerns about the scope of the proposed

course of action as well as identify significant resources and suggested alternatives.

Scoping comments shall be considered during the study process and in preparation of the

draft EIS. A total of 71 participants signed in for the scoping meetings, with 49 at

Houma, Louisiana, and 22 at Morgan City, Louisiana.

A total of 43 multi-part comments were received during the comment period, of which

six were copies of letters, two were comment forms, and one was from the Web site.

Twenty individuals expressed comments at the Houma scoping meeting and 14

individuals expressed comments at the Morgan City scoping meeting. A total of nine

written comments (letter, e-mail, comment form, and Web site) were received during the

comment period.

A scoping comment may contain several specific comments directed at multiple areas of

concern. Hence, a single comment could potentially be addressed in multiple sections of

the draft EIS. A total of 164 specific comments were expressed.

The comments were categorized according to their applicability to the EIS. EIS

categories include: Purpose and Need; Alternatives; Affected Environment;

Environmental Consequences; and Consultation, Coordination, and Compliance with

Regulations. Although an individual scoping comment may be categorized under more

than one EIS subject matter heading, no comment was assigned to more than three

categories.

Table 1 displays the categorization of specific comments by EIS subject matter. The

most numerous comments were expressed regarding the Alternatives followed by

Environmental Consequences, Affected Environment, Compliance then Purpose and

Need.

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Table 6.1. Categorization of Scoping Comments by Draft EIS Subject Matter. P&N = Purpose and

Need, ALT = Alternatives, AE = Affected Environment, EC = Environmental Consequences, and CC

= Consultation, Coordination, and Compliance with Regulations.

Source of Scoping Comment P&N ALT AE EC CC Totals

Scoping Meetings 32 50 41 39 31 193

Scoping Comment Cards 1 3 1 0 0 5

Scoping Comment Letters 10 14 14 24 14 76

Scoping Comment E-mails 0 0 0 0 0 0

Scoping Comments Web Site 0 1 0 1 0 2

Totals 43 68 56 64 45 276

A more detailed account of individual comments accounted for in Table 6.1 is in the project scoping report

and can be made available upon request.

Purpose and Need

A majority of the comments received in this category stressed the need for greater influx

of both freshwater and sediment to Terrebonne Parish. Several comments indicated,

however, that the project title is misleading: “Consider clarifying your goal to

distinguish if it is really to move water more efficiently to the east or to move more water

into the GIWW with the hope of moving water further east all the way to Grand Bayou

and certainly to the Houma Navigation Channel.” Several respondents stressed the

urgency of implementing this project.

Alternatives

Using pipelines to distribute both water and sediment was the most common suggestion.

“Alternatives such as the pipeline redistribution of water and sediment should also be

considered as an alternative, but with caution because of the potential high cost and

other uncertainties such as land rights that exist with transporting water and sediment

long distances.” One commenter questioned whether scenarios are included using

hydrodynamic models or ecological models. Other comments included suggesting

restrictions on existing openings and the consideration of two-way conduit channels.

Affected Environment

Most comments relating to the proposed action’s effect on the area concerned the

management of water flowing through the Gulf Intracoastal Waterway. Need bank line

stabilization of the GIWW and aggressive water management using, as much as possible,

the existing natural bayous, waterways, and existing canals on the western part of the

parish. Worries regarding erosion, bank line stabilization and flooding of existing

wetlands and floating marshes dominated the comments received. “Since the Avoca

Levee was extended most of this valuable wetland has subsided and now that has created

a dilemma to the degree that the land owners do not want any more water into their

marshes and wetlands for fear of drowning what little wetlands and floating marshes they

have left.”

Environmental Consequences

Several comments were positive in nature, indicating that the increase of fresh-water flow

into the Terrebonne marshes would greatly enhance the area. “We are supportive of the

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concept of increasing Atchafalaya River influence into the starving marshes of southern

and eastern portions of Terrebonne Parish.” Some concerns were raised regarding the

potential increase of water velocity. The increasing water levels and velocity are the

greatest enemies to these freshwater marshes, not saltwater intrusion.

Consultation, Coordination, and Compliance with Regulations

The majority of comments received in this area concerned this projects relation to other

projects and plans. Consider combining the projects and monies in both St. Mary and

Terrebonne Parishes to rebuild the coast. Do not look at them as separate projects, they

should be combined. Some clarification regarding project scope and budget was also

requested. Requested clarification on the $2 billion total cost for the project, specifically

if the $2 billion was only for the study or if it include construction for the five to fifteen

designated near-term projects.

6.2 Other Public Comments

6.2.1 Federal and State Agencies

A project kick-off meeting was held on January 13, 2009 to present the study authority,

purpose, goals and objectives. Federal, State and local agencies from Louisiana

participated in the discussions. Representatives of Federal and State agencies were

invited to be members of the Project Delivery Team (PDT) and the Habitat Evaluation

Team (HET). The PDT facilitates the interagency collaboration and coordination

necessary for study execution. Agency team members provide guidance and

recommendations throughout the planning process to assure the successful delivery of a

quality product.

The HET is part of the PDT and is composed of resource agency representatives. The

HET performs planning and technical assessments consistent with their agency

responsibilities and expertise. The HET has been involved at all stages of the planning

process, and has assisted with the development, evaluation, and analysis of project

alternatives. The HET has participated in the public information/involvement program,

exchanged study information, provided recommendations, and assisted in the resolution

of any interagency issues that may have surfaced in the study process. The HET was an

integral part of the Wetland Values Assessment process to determine the habitat value of

the alternatives.

Federal and State agencies are also involved through the NEPA process, with some

agencies serving as official cooperating agencies and other agencies with official

coordination and consultation roles.

6.2.2 Land Owner, Non-Governmental Organization (NGO), Parish and Other

Involvement

Meetings were held to provide opportunities for landowners, NGOs, the Parish and other

interested parties to see progress on the project and to solicit feedback from the attendees.

Federal and state agencies frequently attended as well.

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6.2.3 Public Comments on the Draft EIS

Copies of this draft EIS will be made available to all interested parties through mailings,

advertisements, media advisories, public meetings, and websites. All comments received

during the 45-day public comment period on the draft EIS will be documented and

responded to in Appendix G. All commenters will be sent a Notice of Availability of this

Integrated Feasibility Study and EIS after its completion.

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7.0 COORDINATION AND COMPLIANCE

This chapter documents the coordination and compliance efforts for this project regarding

statutory authorities including: environmental laws, regulations, executive orders,

policies, rules, and guidance. Consistency of the Recommended Plan (RP) and other

Louisiana coastal restoration efforts is also addressed.

7.1 USACE Principles and Guidelines (P&G)

The guidance for conducting Civil Works planning studies (ER 1105-2-100) is based on

the P&G adopted by the Water Resources Council. The P&G are composed of two parts:

The Economic and Environmental Principles and Guidelines for Water and Related Land

Implementation Studies and the Economic and Environmental Guidelines for Water and

Related Land Resources Implementation Studies. The P&G require the systematic

formulation of alternative plans to ensure all reasonable alternatives are evaluated. The

P&G also include guidance on the development and structure of the studies and reports

for projects requiring specific authorization.

Under the study guidance for projects requiring specific authorization, the feasibility

study requirements include documentation of the planning process and environmental

compliance. The feasibility report is required to document the planning process and all

assumptions made during plan formulation along with the rationale for decision making.

The report should culminate in a recommended plan along with documentation of how

the plan relates to the NED, NER, or a combined NED/NER plan. If the project deviates

from those plans, the degree and reasons for the deviation must be documented. The

feasibility study is also required to document compliance with applicable environmental

laws and regulations which can be included as an EA or EIS included with the feasibility

study or an integrated feasibility study document with NEPA information.

Planning for this feasibility study has been conducted in accordance with the ER 1105-2-

100 guidance. This report is an integrated feasibility study and EIS. Policy reviews have

been conducted to ensure compliance with applicable USACE policies.

7.2 Environmental Coordination and Compliance

Following completion of the final integrated report, the Assistant Secretary of the Army

for Civil Works will issue a written Record of Decision (ROD) concerning the proposed

action. The ROD will be issued within a framework of laws, regulations, executive

orders, policies, rules, and other guidance. These authorities establish regulatory

compliance standards for environmental resources pertaining directly to USACE

management of water resources development projects, or provide planning guidance for

the management of environmental resources. Relevant Federal statutory authorities and

executive orders are listed in Table 7.1. Relevant State of Louisiana statutory authorities

are listed in Table 7.2. Full compliance with statutory authorities will be accomplished

upon review of the final integrated feasibility report and Supplemental Environmental

Impact Statement by appropriate agencies and the public and the signing of a Record of

Decision (ROD), in compliance with the Fish and Wildlife Coordination Act (1958).

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Table 7.1. Relevant Federal Statutory Authorities and Executive Orders (Note: This list is not

complete or exhaustive)

Abandoned Shipwreck Act of 1987

American Indian Religious Freedom Act of 1978

Anadromous Fish Conservation Act of 1965

Archaeological Resources Protection Act of 1979

Archaeological and Historical Preservation Act of 1974

Bald Eagle Protection Act of 1940

Clean Air Act of 1970

Clean Water Act of 1977

Coastal Barrier Improvement Act of 1990

Coastal Barrier Resources Act of 1982

Coastal Wetlands Planning, Protection, and Restoration

Act of 1990

Coastal Zone Management Act of 1972

Coastal Zone Protection Act of 1996

Comprehensive Environmental Response,

Compensation, and Liability Act of 1980

Consultation and Coordination with Indian Tribal

Governments (EO 13175) of 2000

Deepwater Port Act of 1974

Emergency Planning and Community Right-to-Know

Act of 1986

Emergency Wetlands Restoration Act of 1986

Endangered Species Act of 1973

Environmental Quality Improvement Act of 1970

Estuaries and Clean Waters Act of 2000

Estuary Protection Act of 1968

Estuary Restoration Act of 2000

Exotic Organisms (EO 11987) of 1977

Farmland Protection Policy Act of 1981

Federal Actions to Address Environmental Justice in

Minority Populations & Low-Income Populations (EO

12898, 12948) of 1994, as amended

Federal Compliance with Pollution Control

Standards (EO 12088) of 1978

Federal Emergency Management (EO 12148) of 1979

Federal Water Pollution Control Act of 1972

Federal Water Project Recreation Act of 1965

Fish and Wildlife Conservation Act of 1980

Fish and Wildlife Coordination Act of 1958

Flood Control Act of 1944

Floodplain Management (EO 11988) of 1977

Food Security Act of 1985

Greening of the Government Through Leadership in

Environmental Management (EO 13148) of 2000

Historic Sites Act of 1935

Historical and Archaeological Data-Preservation

Act of 1974

Indian Sacred Sites (EO 13007) of 1996

Invasive Species (EO 13112) of 1999

Land & Water Conservation Fund Act of 1965

Magnuson-Stevens Fishery Conservation and

Management Act of 1976, as amended

Marine Mammal Protection Act of 1972

Marine Protected Areas (EO 13158) of 2000

Marine Protection, Research, and Sanctuaries

Act of 1972

Migratory Bird Conservation Act of 1929

Migratory Bird Treaty Act of 1918

Migratory Bird Habitat Protection (EO 13186) of 2001

National Environmental Policy Act of 1969

National Historic Preservation Act of 1966

National Invasive Species Act of 1996

Native American Graves Protection and

Repatriation Act of 1990

Neotropical Migratory Bird Conservation Act of 2000

Noise Control Act of 1972

Nonindigenous Aquatic Nuisance Prevention and

Control Act of 1996

North American Wetlands Conservation Act of 1989

Oil Pollution Act of 1990

Outer Continental Shelf Lands Act of 1953

Pollution Prevention Act of 1990

Prime or Unique Farmlands, 1980 CEQ

Memorandum

Protection and Enhancement of the Cultural

Environment (EO 11593) of 1971

Protection and Enhancement of Environmental Quality

(EO 11991) of 1977

Protection of Children from Environmental Health

Risks and Safety Issues (EO 13045) of 1997

Protection of Cultural Property (EO 12555) of 1986

Protection of Wetlands (EO 11990) of 1977

Reclamation Projects Authorization and Adjustments

Act of 1992

Recreational Fisheries (EO 12962) of 1995

Resource Conservation and Recovery Act of 1976

Responsibilities of Federal Agencies to Protect

Migratory Birds (EO 13186) of 2001

Rivers and Harbors Acts of 1899, 1956

River and Harbor and Flood Control Act of 1970

Safe Drinking Water Act of 1974

Submerged Land Act of 1953

Sustainable Fisheries Act of 1996

Toxic Substances Control Act of 1976

Uniform Relocation Assistance and Real Property

Acquisition Policies Act of 1970 (Public Law 91-646)

Water Resources Development Acts of 1976, 1986,

1990, 1992, and 2007

Water Resources Planning Act of 1965

Watershed Protection & Flood Prevention Act of 1954

Water Pollution Control Act Amendments of 1961

Wild and Scenic River Act of 1968

Wilderness Act of 1964

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Table 7.2. Relevant State Statutory Authorities (Note: This list is not complete or

exhaustive)

Air Control Act

Archeological Treasury Act of 1974

Louisiana Coastal Resources Program

Louisiana Natural and Scenic Rivers System Act

Louisiana Threatened and Endangered Species and

Rare & Unique Habitats

Protection of Cypress Trees

Water Control Act

7.2.1 U.S. Fish and Wildlife Coordination Act

The USACE has coordinated with the US Fish and Wildlife Service, NMFS, and the

LDWF per the Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C.

661 et seq.). A coordination act letter report has been received and the comments

incorporated into the project plan as appropriate. The Fish and Wildlife Coordination Act

authorizes the Secretaries of Agriculture and Commerce to provide assistance to and

cooperate with Federal and state agencies to protect, rear, stock, and increase the supply

of game and fur-bearing animals, as well as to study the effects of domestic sewage, trade

wastes, and other polluting substances on wildlife.

The amendments enacted in 1946 require consultation with the Fish and Wildlife Service

and the fish and wildlife agencies of states where the "waters of any stream or other body

of water are proposed or authorized, permitted or licensed to be impounded, diverted or

otherwise controlled or modified" by any agency under a Federal permit or license.

Consultation is to be undertaken for the purpose of "preventing loss of and damage to

wildlife resources."

US Fish and Wildlife Service Position and Recommendations and USACE

Responses

The following information on the US Fish and Wildlife Service’s position and

recommendations for the LCA-ARTM study comes from the Draft Fish and Wildlife

Coordination Act Report as detailed in Appendix B of this report.

Having worked very closely with the Corps throughout the formulation and evaluation of

project alternatives, we are very familiar with the study’s substantial cost and schedulerelated constraints, as well as the benefits assessment errors discussed previously.

Unfortunately, those constraints have precluded the consideration of truly large-scale

ecosystem restoration efforts that are needed in the study area, perhaps more so than

anywhere else along the Louisiana coast, due to the hydrologic complexity of the area

and its rapid wetland loss rate. Consequently, the RP should be viewed as an array of

short-term measures, and that the assessment of long-term and more effective alternatives

remain to be undertaken.

Study schedule constraints have also precluded opportunities for iterative project

refinement based on earlier analysis. Because such project refinement could not be

undertaken, the RP may result in unnecessary wetland impacts and reduced project cost

effectiveness. The study schedule constraints have also precluded correction of many of

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the known planning and evaluation errors. However, some of those errors and issues are

likely of lesser magnitude than those resulting from the significant uncertainties

associated with hydrologic modeling inaccuracies and those of the associated benefits

assessment methodologies. When the study schedule precludes correction of known

errors and assessment deficiencies, proceeding with authorization and construction of

projects is far from ideal. Yet, the need to take quick action to stem rapid degradation and

wetland loss may to some extent counterbalance the reasonable expectation to achieve

higher-quality planning and benefits assessments. Accordingly, the Service supports

implementation of the RP, provided that the following additional assessment work is

continued during the remaining planning phase and completed during the

preconstruction, engineering, and design phase, to address outstanding major issues that

could result in substantial improvements and/or modifications to the selected plan.

Failure to make significant progress on the following recommendations would result in

quality of impact/benefits disclosure significantly less than that typically associated with

feasibility-level planning and assessment. Furthermore, because of the schedule-driven

decision to accept errors, the Service is unable to entirely fulfill our Coordination Act

responsibilities until the following major issues are addressed:

1. The Corps shall pursue additional hydrologic modeling and benefit analysis of various

sized and designed enlargements of Grand Bayou Canal/Bayou L’Eau Bleu (measures

ED3, ED5, ED6, and ED7) to avoid unnecessary construction impacts and

unnecessary canal-induced saltwater intrusion impacts. That work should also include

efforts to assess project-related effects of reduced freshwater inflows to the Barataria

Basin. The Service and other interested natural resource agencies should be involved

in this effort.

USACE Response: Concur. The recommended hydrologic modeling and benefit

analysis, including analysis of effects on the Barataria Basin, will be conducted during

the pre-construction engineering and design phase. USACE will coordinate with the

Service and other interested agencies in this effort.

2. The Corps shall pursue additional hydrologic modeling and benefits analysis of various

sized and designed enlargements of St. Louis Canal (measure ED2) to avoid

unnecessary construction impacts and unnecessary canal-induced saltwater intrusion

impacts. Following those additional assessments (qualitatively or quantitatively), the

cost effectiveness of the Grand Bayou and St. Louis Canal enlargements should be

ranked to determine whether they both should be included in the RP. The Service and

other interested natural resource agencies should be involved in this effort.

USACE Response: Concur. The recommended hydrologic modeling, benefit analysis,

and cost effectiveness analysis will be conducted during the pre-construction

engineering and design phase. USACE will coordinate with the Service and other

interested agencies in this effort.

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3. The Corps shall pursue additional hydrologic modeling and assessment of benefits and

impacts resulting from the HNC Lock Multi-purpose Operations Project to more

accurately assess anticipated benefits and impacts, especially that of impacts below the

Lock. This revised assessment of HNC Lock Multi-purpose Operations should include

the following:

a) Assess whether the existing model grid in the area south of the HNC Lock is

adequate to simulate lock-related hydrology there. If not, revisions to the model

grid should be undertaken.

b) Less than half of the water rerouted from the lower HNC via HNC Lock’s MPO

is currently accounted for elsewhere. Model results should be re-examined to

find the unaccounted for flow and determine a benefit for that flow.

c) The Morganza Project’s Falgout Canal water control structures should be

included in the hydraulic model.

d) Review and correct if necessary, the Lake Boudreaux water mixing parameters

within the hydraulic model to validate/correct the predicted trends of FWP

increasing salinities north of the HNC Lock.

e) The FWP increasing salinity trend north of the HNC Lock may be related to

operation of the HNC Lock sluice gates. The size and operation of those sluice

gates should be described.

f) If those sluice gates are determined to be the cause of increased FWP salinities

north of the HNC Lock, the Service recommends that alternative sluice gate

operations should be assessed to avoid FWP salinity increases. The Service and

other interested natural resource agencies should be involved in this effort.

USACE Response: Concur. The recommended hydrologic modeling and assessment of

benefits and impacts related to the multi-purpose operation of the HNC Lock Complex

will be conducted during the pre-construction engineering and design phase. This will

include assessment of the adequacy of the existing model grid, re-examination of

model results for unaccounted-for HNC flows, inclusion of the Falgout Canal

structures, review of the predicted Lake Boudreaux salinity trends, and assessment of

alternative sluice gate operations on the HNC Lock. USACE will coordinate with the

Service and other interested natural resource agencies in these efforts.

4. The Corps shall avoid adverse impacts to bald eagle nesting locations and wading bird

colonies through careful design of project features and timing of construction. A

qualified biologist should inspect the proposed work site for the presence of

undocumented wading bird nesting colonies and bald eagles during the nesting season

(i.e., February 16 through October 31 for wading bird nesting colonies, and October

through mid-May for bald eagles).

USACE Response: Concur. USACE will avoid adverse impacts to bald eagle nesting

locations and wading bird colonies. A qualified biologist will inspect proposed work

sites for the presence of wading bird nesting colonies and bald eagles during the

nesting season.

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5. Unless needed for construction of spoil banks, dredged material should be used to

create marsh in strategic locations (to the greatest degree possible). The Service and

other interested natural resource agencies should be involved in this effort.

USACE Response: Concur. Dredged material will be used to the maximum extent

practicable to create marsh. Sampling and testing of material to be dredged will be

completed during the initial phases of pre-construction engineering and design which

will assist in determining the suitability of the material for marsh creation. USACE

will coordinate with the Service and other interested natural resource agencies in these

efforts.

6. Operation plans for project water control structures should be developed in

coordination with the Service and other interested natural resource agencies. Those

operation plans should incorporate flexibility to respond to changing environmental

conditions.

USACE Response: Concur. Operation plans for water control structures will be

developed during pre-construction engineering and design in coordination with the

Service and other interested natural resource agencies.

7. The Corps shall establish and continue coordination with the Louisiana Department of

Wildlife and Fisheries (225/765-2360) regarding the planning of project features that

will impact the Pointe-aux-Chenes Wildlife Management Area and State owned and

managed oyster seed grounds. Coordination shall also be re-established prior to

construction and any subsequent maintenance.

USACE Response: Concur. USACE will coordinate with the Louisiana Department of

Wildlife and Fisheries.

7.2.2 Clean Water Act – Section 404(b)(1)

The USACE is responsible for administering regulations under Section 404(b)(1) of the

CWA. Potential project-related impacts subject to these regulations, such as the

discharge of dredged material into wetlands to create marsh and ridge habitat, have been

evaluated in compliance with Section 404(b)(1) of the CWA (Appendix D). The

evaluation of potential impacts to water quality indicated that, on the basis of the

guidelines, the proposed disposal sites for the discharge of dredged material comply with

the requirements of these guidelines, with the inclusion of appropriate and practicable

methods to minimize adverse effects to the aquatic ecosystem. The 404(b)(1) will be

signed after the receipt of the 401 Water Quality Certification from the State of

Louisiana. Further environmental analysis and documentation, including updates to the

Section 404(b)(1) evaluation, will be prepared during pre-construction engineering and

design to address potential changes in disposal locations and associated impacts.

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7.2.3 Section 122 of the Rivers and Harbors Act

Section 122 of the Rivers and Harbors Act of 1970 (Public Law 91-611, 84 STAT. 1823)

requires that consideration be given to possible adverse economic, social and

environmental effects. It also requires that final decisions on the project be made in the

best overall public interest, taking into consideration the need for flood control,

navigation and associated purposes; and the associated costs of eliminating or minimizing

the following adverse affects:

Air, water and noise pollution;

Destruction or disruption of man-made and natural resources, esthetic values,

community cohesion, and availability of public facilities and services;

Adverse employment effects;

Tax and property value losses;

Injurious displacement of people, businesses and farms;

Disruption of desirable community and regional growth.

Alternative 2 (RP) would have no significant impacts on Section 122 identified

economic, social or environmental resources.

7.2.4 Coastal Zone Management Act of 1972

Section 307 of the Coastal Zone Management Act (CZM) of 1972 (16 U.S.C.

1456(c)(1)(A)) directs Federal agencies proposing activities or development projects

(including civil work activities), whether within or outside the coastal zone, must assure

that those activities or projects are consistent, to the maximum extent practicable, with

the approved state coastal zone management program. A Consistency Determination is

included with this report (Appendix E) and was submitted to Louisiana Department of

Natural Resources (LDNR) for consistency review. Implementation of the RP is

considered consistent, to the maximum extent practicable, with the approved Louisiana

state coastal management program. Concurrence was provided by the Louisiana

Department of Natural Resources by letter dated 30 July 2010 (see Appendix E).

7.2.5 Endangered Species Act of 1973

Threatened and endangered species protected under the ESA, as amended, may be

present in the project area. No critical habitats for those species would be directly

affected, and no indirect adverse impacts are expected to such habitats. As provided by

the implementing regulations of the ESA, a biological assessment has been prepared and

provided to the USFWS and NMFS to address the potential for the proposed action to

affect listed species. The biological assessment concludes that threatened and

endangered species that may be present in the project area are not likely to be adversely

affected by the proposed action. The USACE will continue to closely coordinate and

consult with the USFWS and the NMFS regarding threatened and endangered species

under their jurisdiction that may be potentially impacted by the proposed action.

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7.2.6 Magnuson-Stevens Fishery Conservation and Management Act of 1996; and

the Magnuson-Stevens Act Reauthorization of 2006 (Essential Fish Habitat)

As directed by the Magnuson-Stevens Fishery Conservation and Management Act

(Public Law 104-297), the USACE has coordinated with NMFS and that agency’s

experts on various marine organisms as well as EFH. The NMFS provided a letter dated

February 17, 2009, to help guide the development of the FS/EIS for the proposed action

(Appendix C). The NMFS identified brown shrimp, white shrimp, red drum, and Gulf

stone crab as species managed by the Gulf of Mexico Fishery Management Council that

have EFH in the proposed action area. The analysis of potential impacts on EFH can be

found in Section 5.10.

7.2.7 Clean Air Act – Air Quality Determination

Compliance with the Clean Air Act (42 U.S.C.A. §§7401) has been fully coordinated

with the Air Quality Section of the LDEQ (see also Section 4.2.4 Air Quality). As

required by Louisiana Administrative Code, Title 33 (LAC 33:III.1405 B), an air quality

applicability determination was made for the RP. This included consideration of the

proposed action for the category of general conformity, in accordance with the Louisiana

General Conformity, State Implementation Plan (LDEQ, 1994). An air quality

determination has been calculated, based upon direct and indirect air emissions (Section

5.4). Generally, since no other indirect Federal action, such as licensing or subsequent

actions would likely be required or related to the restoration construction actions, it is

likely that indirect emissions, if they would occur, would be negligible.

7.2.8 National Historic Preservation Act of 1966

In compliance with Section 106 of the NHPA, as amended and 36 CFR 800, Federal

agencies are required to identify and consider potential effects that their undertakings

might have on significant historic properties, districts, sites, buildings, structures, or

objects that are included in or are eligible for inclusion in the National Register.

Additionally, a Federal agency shall consult with any tribe that attaches religious and

cultural significance to such properties. Agencies shall afford the State Historic

Preservation Office (SHPO) and tribes a reasonable opportunity to comment before

decisions are made. Accordingly, coordination of the proposed action with the SHPO

and tribes has been initiated.

7.2.9 Farmland Protection Policy Act (Prime and Unique Farmlands)

The purpose of the Farmland Protection Policy Act (7 U.S.C. 658) is to minimize the

extent to which Federal programs contribute to the unnecessary and irreversible

conversion of farmland to non-agricultural uses. The RP would not impact any prime

and unique farmland. Hence, there would be no unnecessary or irreversible conversion

of farmland to non-agricultural uses.

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7.2.10 Executive Order 13186 – Migratory Bird Habitat Protection

Executive Order 13186 proclaims the intent to support the conservation of previous

migratory bird conventions by integrating bird conservation principles, measures, and

practices into agency activities and by avoiding or minimizing, to the extent practicable,

adverse impacts on migratory bird resources when conducting agency actions. This

Executive Order requires environmental analyses of Federal actions required by the

NEPA or other established environmental review processes evaluate the effects of actions

and agency plans on migratory birds, with emphasis on species of concern. In addition,

each Federal agency shall restore and enhance the habitat of migratory birds, as

practicable. Implementation of the RP would result in a net increase in migratory bird

habitat.

7.2.11 Executive Order 12898 – Environmental Justice

Concern with EJ issues can be traced to Title VI, Section 601 of the Civil Rights Act of

1964 (Public Law 88-352):

No person in the United States shall, on the grounds of race, color, or national

origin, be excluded from participation in, be denied the benefits of, or be

subjected to discrimination under any program or activity receiving Federal

financial assistance.

On February 11, 1994, President Clinton issued Executive Order 12898 regarding Federal

actions to address EJ issues in minority populations and low-income populations:

To the greatest extent practicable and permitted by law, and consistent with the

principles set forth in the report on the National Performance Review, each

Federal agency shall make achieving environmental justice part of its mission by

identifying and addressing, as appropriate, disproportionately high and adverse

human health or environmental effects of its programs, policies, and activities on

minority populations and low-income populations in the United States and its

territories and possessions, the District of Columbia, the Commonwealth of

Puerto Rico, and the Commonwealth of the Mariana Islands.

Executive Order 12898 is designed to focus Federal attention on the environmental and

human health conditions in minority communities and low-income communities. The

order is also intended to promote non-discrimination in Federal programs substantially

affecting human health and the environment, and to provide minority communities and

low income communities access to public information on, and an opportunity for public

participation in, matters relating to human health or environmental planning, regulations,

and enforcement. Potential EJ issues have been considered throughout the entire study

process, and will continue to be considered through project implementation. As part of

the NEPA process, a scoping input request was provided to the public and interested

parties. The scoping comments did not identify any potential EJ issues. The USACE is

committed to ensuring that any potential EJ issues are addressed as the study proceeds.

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The proposed ecosystem restoration measures would equally impact all potential users in

the area. There would be no potential EJ issues from implementing the RP.

7.2.12 Executive Order 13112 – Invasive Species

On February 3, 1999, President Clinton issued Executive Order 13112 to prevent the

introduction of invasive species and provide for their control and to minimize the

economic, ecological, and human health impacts that invasive species cause by

establishing the National Invasive Species Council. The RP is consistent with Executive

Order 13112 to the extent practicable and permitted by law and subject to the availability

of appropriations, and within Administration budgetary limits. The RP will use relevant

programs and authorities to prevent the introduction of invasive species and not

authorize, fund, or carry out actions likely to cause or promote the introduction or spread

of invasive species in the United States or elsewhere, unless the USACE has determined

and made public its determination that the benefits of such actions clearly outweigh the

potential harm caused by invasive species, and that all feasible and prudent measures to

minimize risk of harm will be taken in conjunction with the actions.

7.2.13 Executive Order 11990 – Floodplain Management

President Jimmy Carter issued Executive Order 11990: Protection of Wetlands on May

24, 1977 (42 FR 26961, 3 CFR, 1977 Comp., p. 121) in order to avoid, to the extent

possible, the long and short term adverse impacts associated with the destruction or

modification of wetlands. Executive Order 11990 directs that each Federal agency shall

take action to minimize the destruction, loss or degradation of wetlands, and to preserve

and enhance the natural and beneficial values of wetlands. Consistent with Executive

Order 11990, the following factors have been considered as part of the alternative plan

formulation process in developing the RP for ecosystem restoration and avoiding

potential effects on the survival and quality of wetlands:

(a) public health, safety, and welfare, including water supply, quality, recharge and

discharge; pollution; flood and storm hazards; and sediment and erosion;

(b) maintenance of natural systems, including conservation and long term productivity of

existing flora and fauna, species and habitat diversity and stability, hydrologic utility,

fish, wildlife, timber, and food and fiber resources; and

(c) other uses of wetlands in the public interest, including recreational, scientific, and

cultural uses.

7.2.14 Executive Order 11988 – Protection of Wetlands

Executive Order 11988 - Floodplain Management directs all Federal agencies to avoid, if

possible, development and other activities in the 100-year base floodplain. Where the

base floodplain cannot be avoided, special considerations and studies for new facilities

and structures are needed.

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Design and siting are to be based on scientific, engineering, and architectural studies;

consideration of human life, natural processes, and cultural resources; and the planned

lifespan of the project. Federal agencies are required to:

• Reduce the risk of flood loss

• Minimize the impact of floods on human safety, health, and welfare

• Restore and preserve the natural and beneficial values served by floodplains in

carrying out agency responsibility

The proposed action area is located in Zone A (no base flood elevation determined) of the

Special Flood Hazard Areas inundated by 100-year flood. Consistent with Executive

Order 11988, implementing the RP would have no significant impacts on the risk of flood

loss. Implementing the RP would have no significant flooding impacts on human safety,

health and welfare. Implementing the RP would contribute to restoring and preserving

the natural and beneficial values served by floodplains.

7.2.15 Uniform Relocation Assistance and Real Property Acquisition Policies Act of

1970

All real estate interests acquired for construction of the RP will be in accordance with the

provisions of the Uniform Relocation Assistance and Real Property Acquisition Policies

Act of 1970 (Uniform Act), as amended in 42 USC 4601-4655, and the Uniform

Regulations contained in 49 C.F.R. Part 24. The Uniform Act sets forth procedures for

the acquisition of private property for public use and specifically requires that the

acquiring agency appraise the real property interests it wishes to acquire and provide the

owner a written summary of the basis for the amount established as just compensation.

7.2.16 Louisiana State Rare, Threatened, and Endangered Species, and Natural

Communities Coordination

The USACE reviewed the database maintained by the Louisiana National Heritage

Program (LNHP) that provides the most recent listing and locations for rare, threatened

and endangered species of plants and animals and natural communities within the State of

Louisiana. The proposed action would not adversely impact any rare, threatened or

endangered species, or unique natural communities. The proposed action would benefit

freshwater marsh, brackish marsh, and estuarine submergent vascular vegetation within

the study area, which are identified as rare and imperiled natural communities for certain

regions of the state (see also Section 5.6 Vegetation Resources).

7.2.17 Clean Water Act – Section 401 Water Quality

Under provisions of the CWA (33 U.S.C. § 1251), any project that involves placing

dredged or fill material in waters of the United States or wetlands, or mechanized

clearing of wetlands, would require a Water Quality Certification from the LDEQ, Office

of Environmental Services. A public notice for the proposed action has been issued.

Along with a copy of this final FS/EIS, an application for Water Quality Certification has

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been submitted by the U.S. Army Engineer District, New Orleans, to the LDEQ, in

accordance with statutory authority contained in LRS: 30:2074 A(3) and provisions of

Section 401 of the CWA (P.L. 92-500, as amended), stating that the proposed placement

of fill material into waters of the state will not violate established water quality standards.

Issuance of an LDEQ State Water Quality Certification is anticipated on 4 October 2010,

prior to the start of the 30-day review period. The Water Quality Certification will be

available for review and placed on www.LCA.Gov when it is issued.

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8.0 CONCLUSIONS AND DETERMINATIONS

8.1 Areas of Controversy and Unresolved Issues

A potential area of controversy is the implementation of the Houma Navigation Lock

construction under a separate authority other than Louisiana Coastal Area.

The recommended plan relies on the operation of the Houma Navigation Canal Lock for

environmental purposes after 2025. The HNC lock complex is a feature of Morganza to

the Gulf of Mexico Hurricane Protection Project. The lock complex ties into adjacent

earthen levees to reduce the risk of hurricane storm surge traveling up the HNC; the 100-

year elevation of the structure is currently estimated to be between 24’ and 26’ elevation.

The lock complex includes a 110’ x 800’ lock, an adjacent 250’ wide sector gate and a

dam closure. For added flexibility, there are ten sluice gates in the t-wall sections of the

lock complex that can be used for drainage/circulation when the sector gate is closed.

Each gate is 5 ft tall by 10 ft wide, with the top of the gate opening at elevation -2.0 ft.

For the purposes of this study, it was assumed that the sluice gates would be open any

time the sector gates were closed, with the exception of storm conditions.

This LCA project proposes the development of an operational plan for the lock complex

structure authorized under Morganza to the Gulf, in order to maximize potential

environmental benefits, both in terms of avoiding saltwater intrusion and optimizing flow

distribution. The proposed action with a constructed lock complex (which comprises the

Future-Without-Project condition for the LCA project after 2025) is to operate it in such a

way that freshwater from the GIWW “escaping” down the Houma Navigation Canal

could be redirected into the surrounding wetlands. Coordinated adaptive management

between ARTM and the Morganza to Gulf Project will be necessary and is

recommended.

The modified operation of the lock complex, however, may prove to be a challenge

because of the effort involved in opening and closing the floodgates. The lock itself will

be operated only when the floodgates are closed to reduce salinity within the channel.

Once closed, the floodgates would force water down other waterways (such as Bayou

Grand Caillou). Saltwater intrusion would be halted at the gate, and freshwater flows

would increase in other waterways. If the HNC Lock is not constructed by 2025, the

benefits of its operation would be lost and other benefits from ARTM from 2025 onward

could be altered. Additionally, since the operations plan for the HNC Lock Complex has

not been finalized, the FWOP condition could be modified. This could also alter the

benefits after the lock is constructed. However, Alternative 2 would likely remain the

NER Plan regardless of the timing of implementation of the HNC Lock Complex.

Relative sea level rise rates higher than the historic rate have the potential to greatly

reduce or even eliminate the benefits of this project. Intermediate RSLR would reduce

benefits by 66% and high RSLR would eliminate benefits. While the intent of EC1165-

2-211 on sea level rise was met, at this time it is impossible to determine the risk of

higher relative sea level rise rates. While this risk exists, the structures in the selected

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plan were designed with adaptive management and RSLR in mind. Various operational

schemes may help to extend the benefits under higher RSLR scenarios.

The degree to which project area marshes will respond to increased freshwater inputs

associated with project features remains unresolved. Specifically, there is uncertainty in

whether or not increasing the flow of fresh water and nutrients to area marshes with little

associated sediment will result in the predicted level of prevention of marsh loss. It is

believed that increased freshwater will benefit study area marshes, but similar projects

that do not utilize sediment inputs that could be used as verification do not currently

exist. Robust monitoring and adaptive management will help to ensure project success

and identify outcomes that should realistically be expected for the project.

Fisheries access impacts on project benefits remain unresolved for some project features.

Inclusion of fisheries access impacts in the calculation of AAHUs may have resulted in

negative AAHUs for all alternatives, despite net gains in wetland acreages. Project

measures are designed to correct significant hydrologic alterations on man-made canals

which are thought to be significant causes of wetland degradation and loss and which

resulted in artificially increased fisheries access. In addition, other natural and man-made

waterways exist for fisheries access. Therefore, the decision was made to eliminate this

potential impact when calculating benefits associated with each alternative. Potential

modifications to this methodology are being investigated by USFWS in consultation with

NMFS, LDWF, and other interested natural resource agencies.

There are also unresolved issues with respect to the best design and operation of some

project features. Further modeling needs to be conducted during pre-construction

engineering and design in order to determine ideal sizes and operational scenarios of

some dredge features and water control structures that could not be fully analyzed during

the planning phase due to time constraints. Specific details on dredged material disposal

acreages and locations also need to be determined. Dredged material will be utilized for

marsh creation to the maximum extent practicable. Sections 3.10.7 and 7.2.1 above

contain details on proposed analyses.

The impacts of the Deepwater Horizon oil spill on coastal Louisiana are uncertain at this

time (August 2010). The impacts of the oil spill as well as the various emergency actions

taken to address oil spill impacts (e.g., use of oil dispersants, creation of sand berms, use

of Hesco baskets, rip-rap, sheet piling and other actions) could potentially impact

USACE water resources projects and studies within the Louisiana coastal area, including

the LCA-ARTM project. Potential impacts could include factors such as changes to

existing, future-without, and future-with-project conditions, as well as increased project

costs and implementation delays. The USACE will continue to monitor and closely

coordinate with other Federal and state resource agencies and local sponsors in

determining how to best address any potential problems associated with the oil spill that

may adversely impact project implementation. Supplemental planning and

environmental documentation may be required as information becomes available. If at

any time petroleum or crude oil is discovered on project lands, all efforts will be taken to

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seek clean up by the responsible parties, pursuant to the Oil Pollution Act of 1990 (33

U.S.C. 2701 et seq.).

8.2 Conclusions

The Recommended Plan (RP) is also the National Ecosystem Restoration Plan (NER).

The RP would create and nourish large areas of various types of nationally significant

wetlands, in addition to reducing the current trend of wetland degradation in the project

area. Restoration of freshwater and nutrient inputs to the project area will result in the

creation and nourishment of a variety of marsh types within the study area. This is done

without increasing flood risk.

• The RP/ NER plan includes the entire project area with the most critical need of

restoration.

• The RP/NER plan does not exceed the legislative mandated cost level limit as

identified in WRDA 2007. The RP meets the intent of the plan as described in the

2004 LCA Report.

• The RP/NER plan can function as a stand-alone project with considerable

benefits.

• The RP/NER plan would provide significant environmental benefits regardless of

the implementation of the HNC Lock Complex.

The RP/NER is the plan that best meets the Louisiana Coastal Area goals and objectives

as well as those identified for the study area in partnership with the State of Louisiana.

The RP/NER is the plan that best meets the P&G’s four criteria of completeness,

effectiveness, efficiency, and acceptability, as well as the Environmental Operating

Principles of environmental sustainability, interdependence, balance and synergy,

accountability, knowledge, respect, and assessing and mitigating cumulative impacts. The

RP/NER plan does meet the current scope and cost authority as per Section 7006 (e) (3)

of WRDA 2007 or Section 902 of WRDA 1986.

8.3 Recommendations

The District Commander has considered all the significant aspects of this study including

the environmental, social, and economic effects, the engineering feasibility, and the

comments received from other resource agencies, the Non-Federal Sponsors, and the

public and has determined that the recommended plan presented in this report is in the

overall public interest and a justified expenditure of Federal funds. As a comprehensive

approach to restore and maintain ecological integrity, including habitats, communities,

and populations of native species, and the processes that sustain them by reducing the

trend of degradation and deterioration to the area between Bayou Lafourche and the

Atchafalaya River, the District Commander recommends the construction of Alternative

2. Alternative 2 (RP/NER) is also a standalone project with significant environmental

benefits and meets most of the study objectives. In cooperation with the USFWS, NOAA

and the State of Louisiana, the Corps planned and would design a project that serves the

needs of the nation.

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The total cost for the project is $305,500,000.00 inclusive of associated investigation,

environmental, engineering and design, construction, supervision and administration, and

contingency costs. The operations and maintenance of this project will be assumed by

the State of Louisiana as the non- Federal sponsor. The project is funded 65% by the

Federal Government and 35% by the non-Federal sponsor, and subject to the

implementation requirements specified in section 3.11 of this report.

The recommendation contained herein reflects the information available at this time,

October 2010 price levels, and current Departmental policies governing the formulation

of individual projects. They do not reflect program and budgeting priorities inherent in

the formulation of a national civil works construction program, nor the perspective of

higher levels of review within the Executive Branch. Consequently, the recommendation

may be modified before being transmitted to the Congress as proposals for authorization

and/or implementation funding.

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9.0 DISTRIBUTION LIST AND OTHER

9.1 Distribution List

Copies of the NOA for this Integrated Feasibility Report and draft EIS will be made

available to all interested parties through mailings, advertisements, media advisories,

public meetings, and websites. The complete distribution list will be kept on file at the

following USACE address and made available upon request.

U.S. Army Corps of Engineers

New Orleans District

P.O. Box 60267

New Orleans, Louisiana 70160-0267

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Table 9.1: Distribution List

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9.2 List of Preparers

Many individuals were involved with the completion of this document. The following

table lists those people who assisted in writing this Integrated Feasibility Study and EIS.

Table 9-2: List of Preparers

Name Job Description/Experience/

Education/Registration

Subject Matter

Boyce, Mayely L MVN Assistant District Council (MVN)/

3 years/J.D./M.E.M., Duke University

Legal Review

Dayan, Nathan S MVN Fisheries Biologist (MVN)/14 years/M.S

Marine Biology, University of

Charleston

Environmental

Oversight

Duncan, Donald L MVS Hydraulic Engineer (MVS)/ 7 years/ M.S.

Civil Engineering, University of Missouri -

Rolla/ Professional Engineer - Missouri

Functional Team Leader

Engineering; Hydraulic

Engineering

Eagan, Timothy P MVS Civil Engineer Technician (MVS)/

3 years/B.A. Information Technology,

Lindenwood University

Data Acquisition &

Support

Geospatial Eng. Rept.

& Mapping

Hanneken, Charles D MVS Ecologist (MVS)/ 3.5 years/ B.S. Truman

State University/ M.S. University of Missouri

St. Louis

Biological Assessment

Hoerner, Melissa L MVS Realty Specialist (MVS)/13 years/M.B.A

Business, SIU-Edwardsville

Real Estate

Kelly, David H MVS Regional Economist (MVS)/16 years/M.S.

Economics, SIU-Edwardsville

Economics

LeBlanc, Wes Coastal Resources Scientist (CPRA)/7

years/M.S. Environmental Planning and

Management, Louisiana State University

CPRA Study Manager

Linkowski, Daniel P MVS Program Analyst (MVS)/ 1 year/ B.S.

Economics, SIU-Edwardsville

Economics

Malin-Boyce, Dr. Susan B Supervisory Archaeologist (MVS)/ 22 years/

Ph.D. Anthropology, New York University

Cultural Resources

Mickal, Sean P MVN Biologist (MVN)/15 years/B.S.

Biology, University of New Orleans

Plan Formulator

Mulford, Darren K MVS Professional Civil Engineer/ 14 yrs / U of

Missouri-Rolla

Civil Design

Nelson, Timothy J MVS Appraiser (MVS)/31 years/Missouri State

Certified Appraiser

Real Estate Appraiser

Oliver, Amanda J MVS Ecologist (MVS)/3 years/M.S. Biology, Saint

Louis University

Environmental

Paille, Ronnie Coastal Wetland Biologist-Ecologist

(USFWS)/23 years/ M.S. Marine Sciences,

Louisiana State University

Habitat Evaluation Team

Leader

Perez, Andrew R MVN Outdoor Recreation Planner (MVN)/5

Years/M.U.R.P.-UNC-Chapel Hill

Recreation/Incidental

Recreation Benefits

Peukert, John MVS Supervisory Archeologist (MVS)/ 9 Years/

M.A. Anthropology, University of

Mississippi/ Registered Professional

Archeologist

Lead Planner/ MVS

Project Manager –

General Project

Oversight

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Radford, Richard T MVN Aesthetics/Visual

Resources

Richardson, Jerica M MVN Archaeologist (MVN)/12 years/ B.A.

Anthropology, Mississippi State

University

Environmental Justice

Coordinator

Runyon, Kip R MVS Fisheries Biologist (MVS)/10 years/M.S.

Zoology, Southern Illinois University

Carbondale

Functional Team

Leader for EIS

Preparation

Scott, Paige MVS Cost Engineer (MVS)/1 year/B.S. Civil

Engineering, Missouri University of Science

and Technology

Cost & Schedule Risk

Analysis

Slattery, Kevin P MVS Environmental Specialist (MVS)/

10 years/B.A. Environmental Studies,

Westminster College/ Certified

Professional in Stormwater Quality

HTRW & Water Quality

Stohl, Melbourne J MVS Mechanical Engineer (MVS)/35 years/

NEED INFORMATION

Mechanical Engineer

Sullivan, Shawn F MVS Biologist (MVS)/7 years/ B.S. Ecology

Southern Illinois University Edwardsville

Biologist

Wood, Cynthia L MVS Administrative Project Support/1 year/

Hickey College

Document Administration

MVN = New Orleans District; MVS = St. Louis District; MVE = Rock Island District;

FWS = U.S. Fish & Wildlife Service; CPRA = Louisiana Office of Coastal Protection &

Restoration

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9.3 Literature Cited

Adkins, G. 1972. A Study of the Blue Crab Fishery in Louisiana. Technical Bulletin No.

3. Louisiana Wildlife and Fisheries Commission. New Orleans, LA.

Anderson, M.G. and B.D.J. Batt. 1983. Workshop on the ecology of wintering waterfowl.

Wildlife Society Bulletin 11:22-24.

Bahr, L.M., Jr., R. Costanza, J.W. Day, Jr., S.E. Bayley, C. Neill, S.G. Leibowitz, and J.

Fruci. 1983. Ecological characterization of the Mississippi deltaic plain region: A

narrative with management recommendations. FWS/OBS-82/69. U.S. Fish and

Wildlife Service, Washington, DC.

Barras, J.A. 2009. Land Area Change and Overview of Major Hurricane Impacts in

Coastal Louisiana, 2004-2008. U.S. Geological Survey Scientific Investigations

Map 2080, scale 1:250,000, 6 p. pamphlet.

Barras, J.A., J.C. Bernier, and R.A. Morton. 2008. Land Area Change in Coastal

Louisiana – a Multidecadal Perspective (from 1956 to 2006). U.S. Geological

Survey Scientific Investigations Map 3019, scale 1:250,000, 14 p. pamphlet.

Barras, J., S. Beville, D. Hartley, S. Hawes, J. Johnston, P. Kemp, Q. Kinler, A. Martucci,

J. Porthouse, D. Reed, K. Roy, S. Sapkota, and J. Shayda, 2003. Historical and

projected coastal Louisiana land changes: 1978-2050: USGS Open File Report

03-334, 39p. (revised Jan. 2004).

Barras, J. A., 2006, Land area change in coastal Louisiana after the 2005 hurricanes--a

series of three maps: U.S. Geological Survey Open-File Report 06-1247

Barras, J.A., P. E. Bourgeois, L. R. Handley. 1994. Land loss in coastal Louisiana 1956-

90: National Biological Survey, National Wetlands Research Center Open-File

Report 94-01. 4 p.

Barrett, B.B. and M.C. Gillespie. 1973. Primary Factors Which Influence Commercial

Shrimp Production in Coastal Louisiana. Technical Bulletin 9. Louisiana Wildlife

and Fisheries Commission. New Orleans, La.

Baxter, K.N. and W.C. Renfro. 1967. Seasonal occurrence and size distribution of

postlarval brown and white shrimp near Galveston, Texas, with notes on species

information. U.S. Fish and Wildlife Service. Fisheries Bulletin 66:149-158.

Blanchard, T.C. 2009. Population Projections of Louisiana Parishes through 2030.

Louisiana State University. 23p.

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Browder, J.A., H.A. Bartley, and K.S. Davis. 1985. A probabilistic model of the

relationship between marshland-water interface and marsh disintegration.

Ecological Modeling 29:245-260.

Browder, J.A., L.N. May, A. Rosenthal, J.G. Gosselink, and R.H. Baumann. 1989. Using

thematic mapper imagery and a spatial computer model to predict future trends in

wetland loss and brown shrimp production in Louisiana. Remote Sensing of the

Environment 28:45-59.

Caffey, R.H. and M. Schexnayder. 2002. Fisheries implications of freshwater diversions

in "An interpretive topic series on Louisiana coastal wetland restoration." Coastal

Wetland Planning, Preservation, and Restoration Act Outreach Committee (eds.),

National Sea Grant Library No. LSU-G-02-003, 7p.

Canadian Wildlife Service and U.S. Fish and Wildlife Service. 1986. North American

waterfowl management plan. U.S. Fish and Wildlife Service, Washington, D.C.

31 pp.

Chabreck, R.H. 1971. The foods and feeding habits of alligators from fresh and saline

environments in Louisiana. Unpublished Proceedings of the 25th Annual

Conference of the Southeast Association of Game and Fish Commissioners.

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Agricultural Experiment Station Bulletin. 664 pp.

Chabreck, R.H. 1972b. Vegetation, water and soil characteristics of the Louisiana coastal

region. Louisiana State University and Agricultural and Mechanical College

Agricultural Experiment Station. 72pp.

Chabreck, R.H. and G. Linscombe. 1982. Changes in vegetative types in Louisiana

coastal marshes over a ten-year period. Louisiana Academy of Sciences 45:98–

102.

Christmas, J.Y., J.T. McBee, R.S. Waller, and FC. Sutter III. 1982. Habitat Suitability

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Condrey, R.P., P. Kemp, J. Visser, J. Gosselink, D. Lindstedt, E. Melancon, G. Pterson,

and B. Thompson. 1995. Status, Trends, and Probable Causes of Change in

Living Resources in the Barataria and Terrebonne Estuarine Systems. BTNEP

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LA.

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Conner, W.H. and J.W. Day, Jr. 1987. The Ecology of Barataria Basin, Louisiana: An

Estuarine Profile. Biological Report 85(7.13). U.S. Fish and Wildlife Service,

Washington, DC.

CWPPRA 2007. Coastal Wetlands Planning, Protection, and Restoration Act

Environmental Work Group Wetland Value Assessment Methodology Coastal

Marsh Community Models, 36 pp.

Daigle, J.J., G.E. Griffith, J.M. Omernik, P.L. Faulkner, R.P. McCulloh, L.R. Handley,

L.M. Smith, and S.S. Chapman. 2006. Ecoregions of Louisiana (color poster with

map, descriptive text, summary tables, and photographs). U.S. Geological Survey

(map scale 1:1,000,000), Reston, Virginia.

Day, J.W. and P.H. Templet, 1989. Consequences of Sea Level Rise: Implications from

the Mississippi Delta. Coastal Management. Vol 17:241-257.

Day, J. W., Jr., C. A. S. Hall, W. M. Kemp, A. Yanez-Arancibia. 1989. Estuarine

Ecology. John Wiley and Sons, New York. 558 pp.

DeLaune, R.D., J.A. Nyman, and W.H. Patrick, Jr. 1994. Peat collapse, ponding and

wetland loss in a rapidly submerging coastal marsh. J. Coast. Res. 10:1021-1030.

DeLaune, R.D., S. R. Pezeshki, J. H. Pardue, J. H. Whitcomb, and W. H. Patrick, Jr.

1990. Some influences of sediment addition to a deteriorating salt marsh in the

Mississippi River deltaic plain: A pilot study. Journal of Coastal Research

6:1:181-188.

DeLaune, R.D., W.H. Patrick, and N. Van Breemen. 1990b. Processes governing marsh

formation in a rapidly subsiding coastal environment. Catena 17:277-288.

Cremlingen, Germany.

DeLaune, R.D., C. J. Smith, and W. H. Patrick. 1983. Relationship of marsh elevation,

redox potential, and sulfide to Spartina alterniflora productivity. Soil Sci. Soc.

AM. J. 47:930-935.

DeLaune, R.D., R.J. Buresh, and W.H. Patrick, Jr. 1979. Relationship of soil properties to

standing crop biomass of Spartina alterniflora in a Louisiana marsh. Estuarine

Coastal Marine Science 8: 477-487.

DeLaune, R.D., W.H. Patrick, Jr. & R.J. Buresh. 1978. Sedimentation rates determined

by 137 Cs dating in a rapidly accreting salt marsh. Nature 275:12. pp. 532-533.

Diagne, A., and W. R. Keithly. 1988. The demand for relaying activities by the Louisiana

oyster industry. Proceedings of the 10th Biannual Conference of the International

Institute of Fisheries Economics and Trade, 10-14 July, Corvallis, Oregon.

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Dow, D.D., W.H. Herke, E.E. Knudsen, B.L. Marotz and E.M. Swenson. 1985.

Hydrography on the Grand Bayou, Louisiana, watershed: influence of wetlandwater interactions on ecosystem function. Symposium of Hydrolographic Society

of America. p 52-71.

Environmental Systems Research Institute, Inc. (ESRI). 2008. Business Analyst

Program: Census 2000 Summary Profile, Census 2000 Detailed Race Profile,

2008/2013 Demographic and Income Profile.

Faller, K. H. 1979. Shoreline as a controlling factor in commercial shrimp production.

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Laboratories, Bay St. Louis, Mississippi, USA, NASA TM-72-732.

Federal Highway Administration (FHWA). 2006. “Highway Construction Noise

Handbook.” Final Report. FHWA, U.S. Department of Transportation. August

2006.

Forsythe, S.W. 1985. The protection of bottomland hardwood wetlands of the lower

Mississippi Valley. Transactions of the North American Wildlife and Natural

Resources Conference 50:566-572.

Gaidry, W.J. and C.J. White. 1973. Investigations of Commercially Important Penaeid

Shrimp in Louisiana Estuaries. Technical Bulletin 8. Louisiana Wildlife and

Fisheries Commission. New Orleans, LA.

Gagliano, S. M. 1999. Faulting, Subsidence and Land Loss in Coastal Louisiana.

Contract No. 68-06-0067. Prepared for U.S. Environmental Protection Agency,

Dallas, TX.

Gosselink, J.G. 1984. The Ecology of Delta Marshes of Coastal Louisiana: A Community

Profile. FWS/OBS-84/09. U.S. Fish and Wildlife Service, Washington, D.C.

Gosselink, J.G. and C.E. Sasser. 1991. An ecological overview of the BaratariaTerrebonne estuary: Processes, scales, and management principles.

Gosselink, J.G. and C.E. Sasser. 1995. Causes of Wetland Loss. D.J. Reed (ed.) pp. 205-

236. In: Current Status and Historical Trends of Hydrological Modification,

Reduction in Sediment Availability, and Habitat Loss/Modification in the

Barataria-Terrebonne Estuarine System. BTNEP No. 20. Barataria Terrebonne

National Estuary Program, Thibodaux, LA.

Guillory, V., J. Geaghan, and J. Roussel. 1983. Influence of Environmental Factors on

Gulf Menhaden Recruitment. Louisiana Department of Wildlife and Fisheries

Technical Bulletin 37. Baton Rouge, LA.

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Gulf of Mexico Fisheries Management Council. 2004. Final Environmental Impact

Statement for the Generic Essential Fish Habitat Amendment to the following

fishery management plans of the Gulf of Mexico. Gulf of Mexico Fishery

Management Council. Tampa, Florida.

Hawes, S.R., and H.M. Perry. 1978. Effects of 1973 floodwaters on plankton populations

in Louisiana and Mississippi. Gulf Research Reports 6(2):109-124.

Heitmeyer, M.E. and L.H. Fredrickson. 1981. Do wetland conditions in the Mississippi

Delta hardwoods influence mallard recruitment? Transactions of the North

American Wildlife and Natural Resources Conference 46:44-57.

Herke, W.H. 1995. Natural fisheries, marsh management, and mariculture: complexity

and conflict in Louisiana. Estuaries 18:10-17.

Joanen, T. and L. McNease. 1972. Population distribution of alligators with special

reference to the Louisiana coastal marsh zones. Unpublished Symposium of the

American Alligator Council, Lake Charles, LA.

Keithly, W.R. Jr., and K. J. Roberts. 1988. The Louisiana oyster industry: economic

status and expansion prospects. Journal of shellfish research. Vol 7:515-525.

Kilgen, R. H. and R. J. Dugas. 1989. The ecology of oyster reefs of the northern Gulf of

Mexico: an open file report . NWRC-open file rep. 89-02.

Knox, G.A. 2001. The ecology of seashores. CRC Press LLC, Boca Rotan, Florida. 557

pp.

Kryter, K. D. 1994. The Handbook of Hearing and the Effects of Noise: Physiology, and

Public Health. McGraw Hill, New York.

Kuecher, G.J. 1994. Geologic Framework and consolidation Settlement Potential of the

Lafourche delta, Topstratum Valley Fill; Implications for Wetland Loss in

Terrebonne and Lafourche Parishes, Louisiana. Doctor of Philosophy

Dissertation. Louisiana State University, Baton Rouge, LA.

Lassuy, D.R. 1983. Species Profiles: Life Histories and Environmental Requirements

(Gulf of Mexico) Brown Shrimp. FWS/OBS-82/11.1. U.S. Fish and Wildlife

Service, Washington, DC.

LeBlanc, D.J. 1994. Prevention and control of wildlife damage-Nutria. United States

Department of Agriculture’s Animal and Plant Health Inspection Service, Port

Allen, Louisiana.

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Lessmann, J.M., I.A. Mendelssohn, M.W. Hester, and K.L. McKee. 1997. Population

variation in growth response to flooding of three marsh grasses. Ecological

Engineering 8:31-47.

Linscombe, G. and K. Kinler. 1994. A Survey of Vegetative Damage Caused by Nutria

Herbivory in the Barataria and Terrebonne Basins. submitted to the BaratariaTerrebonne National Estuary Program. Louisiana Department of Wildlife and

Fisheries, Baton Rouge, LA.

Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands

Conservation and Restoration Authority. 1998. Coast 2050: Toward a Sustainable

Coastal Louisiana,. Louisiana Department of Natural Resources. Baton Rouge,

La.

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Pulpwood Production. Office of Forestry, Baton Rouge, LA.

Louisiana Department of Environmental Quality. 2008. 2008 Louisiana Water Quality

Inventory: Integrated Report. Louisiana Department of Environmental Quality,

Office of Environmental Assessment, Water Quality Assessment Division, Baton

Rouge.

Louisiana Department of Environmental Quality. 2008. 2007 Louisiana Ambient Air

Monitoring Network Annual Report.

Louisiana Department of Wildlife and Fisheries, Louisiana Sea Grant, Louisiana Aquatic

Invasive Species Task Force. 2005. State management plan for aquatic invasive

species in Louisiana. Center for Bioenvironmental Research at Tulane and Xavier

Universities. 81 pp.

Martin, R.P. and G.D. Lester. 1990. Atlas and Census of Wading Fird and Seabird

Nesting Colonies in Louisiana: 1990. Special Publication No. 3. Louisiana

Department of Wildlife and Fisheries, Louisiana Natural Heritage Program, Baton

Rouge, LA.

McDaniel, D.R. and G.J. Trahan. 2007. Soil Survey of Terrebonne Parish, Louisiana.

United States Department of Agriculture, Natural Resources Conservation

Service, in cooperation with Louisiana Agricultural Experiment Station and

Louisiana Soil and Water Conservation Committee.

McKee, K.L. and I.A. Mendelssohn. 1989. Response of a freshwater marsh plant

community to increased salinity and increased water level. Aquatic Biology.

34:301-316.

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Michot, T.C. 1996. Marsh loss in coastal Louisiana: Implications for management of

North American Anatidae. Gibier Faune Sauvage. Game Wildlife 13:941-957.

Minello, T.J., R.J. Zimmerman, and R. Medina. 1994. The importance of edge for natant

macrofauna in a created salt marsh. Wetlands 14:184-198.

Mitchell, K. 1991. Wildlife Resources of the Barataria-Terrebonne Estuary. pp. 3339-

346. In: Barataria-Terrebonne National Estuary Program Scientific-Technical

Committee Data Inventory Workshop Proceedings. BTNEP Publication - 5,

Thibodaux, LA.

Mitsch, W.J. and J.G. Gosselink. 1993. Wetlands. 2nd Ed. Van Nostrand Reinhold, New

York, USA. 722pp.

Morgan, J. P., and Larimore, P. B., 1957, Changes in the Louisiana shoreline:

Transactions of the Gulf Coast Association of Geological Societies, v. 7, p. 303-

10.

Morton, R., J. Bernier, J. Barras, and N. Fernia. 2005. Rapid subsidence and historical

wetland loss in the Mississippi Delta Plain, likely causes and future implications:

U.S. Geological Survey Open-File Report 2005-1216, 124 pp.

http://pubs.usgs.gov/of/2005/1216/, accessed August 9, 2006.

Mossa, J. D.M. Lindstedt, D. Cahoon, and J. Barras. 1990. Environmental Characteristics

and Habitat Change for the Louisiana Coastal Zone. pp. 167-204. In: D.R.

Cahoon and C.G. Groat eds., A study of Marsh Management Practice in Coastal

Louisiana, Volume II, Technical Description. Final report submitted to Minerals

Management Service, New Orleans, LA. OCS Study/MMS 90-0075.

Muncy, R.J. 1984. Species Profiles: Life Histories and Environmental Requirements

(Gulf of Mexico) White Shrimp. FWS/OBS-82/11.20. U.S. Fish and Wildlife

Service, Washington, DC.

Nance, J.M. and S. Nichols. 1988. Stock Assessments for Brown, White and Pink Shrimp

in the U.S. Gulf of Mexico, 1960-1986. NOAA Technical Memorandum SEFCNMFS-203. National Oceanic and Atmospheric Administration, Galveston, TX.

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Maryland, personal communication.

National Marine Fisheries Service. 2009. Fisheries of the United States, 2008. National

Oceanic and Atmospheric Administration. United States Department of

Commerce. Silver Spring, Maryland.

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Nowak, D.J. 2003. Personal communication, David J. Nowak, Project Leader, USDA

Forest Service, Northeastern Research Station, 5 Moon Library, SUNY-CESF,

Syracuse, New York.

Nyman, J.A., R.J. Walters, R.D. Delaune, and W.H. Patrick, Jr. 2006. Marsh vertical

accretion via vegetative growth. Estuarine, Coastal and Shelf Science 69: 370-

380.

O’Neil, T. 1949. The muskrat in the Louisiana coastal marsh. Louisiana Department of

Wildlife and Fisheries. New Orleans, LA.

Penland, S., K.E. Ramsey, R.A. McBride, J.T. Mestayer, and K.A. Westphal. 1988. Relative

Sea Level Rise and Delta-Plain Development in the Terrebonne Parish Region.

Coastal Geology Technical Report No. 4. Louisiana Geological Survey, Baton

Rouge, LA.

Penland, Shea, and Boyd, Ron, 1981, Shoreline changes on the Louisiana barrier coast:

Oceans, v. 81, p. 209-219.

Perret, W.S., B.B. Barrett, W.R. Latapie, J.F. Pollard, W.R. Mock, G.B. Adkins, W.J.

Gaidry, and C.J. White. 1971. Cooperative Gulf of Mexico estuarine inventory

and study, Louisiana. Louisiana Wildlife and Fisheries Commission, New

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Pierce, M.E., and J.T. Conover. 1954. A study o f the growth of oysters under different

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Perry, H.M. 1975. The blue crab fishery in Mississippi. Gulf Research Reports. 5:39-57.

Perry, H.M. and T.D. McIlwain. 1986. Species Profiles: Life Histories and

Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of

Mexico) Blue Crab. FWS/OBS-82/11.55. U.S. Fish and Wildlife Service,

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Platt, S.G., C.G. Brantley, and R.W. Hastings. 1990. Food habits of juvenile American

alligators in the upper Lake Pontchartrain estuary. Northeast Gulf Science 11:123-

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Platt, S.G., C.G. Brantley, and Lance W. Fontenot. 1989. Herpetofauna of the Manchac

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Louisiana Acad. Sci. 52:22-28.21

Raveling, D.G. and M.E. Heitmeyer. 1989. Relationships of population size and

recruitment of pintails to habitat conditions and harvest. Journal of Wildlife

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Reinecke, K.J., C.W. Shaiffer, and D. Delnicki. 1987. Winter survival of female mallards

in the Lower Mississippi Valley. TNAWNR Conf 52:258-263.

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Arts Thesis. University of Southwestern Louisiana, Lafayette, LA.

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Carol Parsons, 2003, Ecosystem Health of the Maurepas Swamp: Feasibility and

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Protection Agency (EPA) Region 6.

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Swarzenski, C.M., T.W. Doyle, B. Fry, and T.G. Hargis. 2008. Biogeochemical

response of organic-rich freshwater marshes in the Louisiana delta plain to

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18:205-228. The Coypu Foundation. http://is.cbr.tulane.edu. Center for

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recent hydrologic changes in a deltaic coast. Estuaries 13:272-281.

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USGS National Wetlands Research Center. 2000. Nutria-Eating Louisiana’s Coast. Fact

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Wildlife Service, Office of Biological Services, FWS/OBS 79/07, 464 maps.

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Harvest and Distribution 2008-2009 and a Survey of Nutria Herbivory Damage in

Coastal Louisiana in 2009. Coastal and Nongame Resources, Louisiana

Department of Wildlife and Fisheries.

Zimmerman, R.J., T.J. Minello, and G. Zamora. 1984. Selection of vegetated habitat by

brown shrimp, Penaeus aztecus, in a Galveston Bay salt marsh. Fishery Bulletin,

US 82:325-336.

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9.4 Glossary

Acceptability – Adequate to satisfy a need, requirement, or standard. One of the U.S.

Army Corps of Engineers requirements for a project.

Adaptive management – An interdisciplinary approach acknowledging our insufficient

information base for decision-making; that uncertainty and change in managed resources

are inevitable; and that new uncertainties will emerge. An iterative approach that

includes monitoring and involves scientists, engineers and others who provide

information and recommendations that are incorporated into management actions; results

are then followed with further research, recommendations and management actions, and

so on.

Air Quality Determination – The Louisiana Department of Environmental Quality

ensures that projects do not adversely affect air quality through this determination as a

requirement of the Clean Air Act.

Alternative Plan – A set of one of more management measures within a subprovince

functioning together to address one or more objectives.

Amplitude – The maximum absolute value of a periodically varying quantity.

Anadromous – Ascending rivers from the sea for breeding.

Anthropogenic – Caused by human activity.

Average Annual Habitat Unit (AAHU) – Represent a numerical combination of habitat

quality and quantity (acres) existing at any given point in time. The habitat units

resulting from the future without- and future with-project scenarios are annualized, and

averaged over the period of analysis, to determine Average Annual Habitat Units

(AAHUs).

Aquaculture – The science and business of farming marine or freshwater food fish or

shellfish, such as oysters, crawfish, shrimp and trout, under controlled conditions.

Benefits – Valuation of positive performance measures.

Benthic – Living on or in sea, lake, or stream bottoms.

Biomass – The total mass of living matter (plant and animal) within a given unit of

environmental area.

Bottomland Hardwood Forest – Low-lying forested wetlands found along streams and

rivers.

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Brackish Marsh (BRM) – Intertidal plant community typically found in the area of the

estuary where salinity ranges between 4–15 ppt.

Chenier Plain – Western part of coastal Louisiana with little influence from Mississippi

and Atchafalaya rivers.

Clean Water Act Section 404 (b) (1) – There are several sections of this Act that pertain

to regulating discharges into wetlands. The discharge of dredged or fill material into

waters of the United States is subject to permitting specified under Title IV (Permits and

Licenses) of this Act and specifically under Section 404 (Discharges of Dredge or Fill

Material) of the Act.

Coast-wide Plan – Combination of alternative plans assembled to address an objective of

set of objectives across the entire Louisiana Coast.

Completeness – The ability of a plan to address all of the objectives. One of the USACE

four requirements for a project.

Comprehensive Plan – Same as Coast-wide Plan.

Conditional Authorization – Authorization for implementation of a project subject to

approval of the project feasibility-level decision document by the Assistant Secretary of

the Army for Civil Works.

Congressional Authorization – Authorization for investigation to prepare necessary

feasibility level report to be recommended for authorization of potential future project

construction by Congress.

Connectivity – Property of ecosystems that allows for exchange of resources and

organisms throughout the broader ecosystem.

Control Structure – A gate, lock, or weir that controls the flow of water.

Crevasse – A breach or gap in the levee or embankment of a river (natural or manmade),

through which floodwaters flow.

Cumulative Impacts – The combined effect of all direct and indirect impacts to a

resource over time.

Datum – A point, line, or surface used as a reference, as in surveying, mapping, or

geology.

Deciduous Forest – Forest composed mostly of trees that lose their leaves in the winter.

Decomposition – Breakdown or decay of organic materials.

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Degradation Phase – The phase of the deltaic cycle when sediments are no longer

delivered to a delta, and it experiences erosion, dieback, or breakup of marshes.

Deltaic Cycle – Capture of the Mississippi River by a distributary that offered a shorter

route to the Gulf of Mexico. After abandonment of an older delta lobe, which would cut

off the primary supply of fresh water and sediment, an area would undergo compaction,

subsidence, and erosion. The old delta lobe would begin to retreat as the gulf advanced,

forming lakes, bays, and sounds. Concurrently, a new delta lobe would begin its advance

gulfward.

Deltaic Deposits – Mud and sand deposited at the mouth of a river.

Deltaic Plain – The land formed and reworked as the Mississippi River switched

channels in the eastern part of the Louisiana coastal area.

Detritus – The remains of plant material that has been destroyed or broken up.

Dewatering – The process of dredged sediments compacting while losing water after

being deposited.

Discharge – The volume of fluid passing a point per unit of time, commonly expressed in

cubic feet per second, millions of gallons per day, or gallons per minute.

Dissolved Oxygen – Oxygen dissolved in water, available for respiration by aquatic

organisms. One of the most important indicators of the condition of a water body.

Direct Impacts – Those effects that result from the initial construction of a measure

(e.g., marsh destroyed during the dredging of a canal). Contrast with “Indirect Effects.”

Diversion – A turning aside or alteration of the natural course or flow of water. In

coastal restoration this usually consists of such actions as channeling water through a

canal, pipe, or conduit to introduce water and water-borne resources into a receiving area.

Dredged material embankments (Spoil Banks, Side-cast Banks, Excavated Material

Banks) – Dredged material removed from canals and piled in a linear mound along the

edge of canals.

Dynamic – Characterized by continuous change and activity.

Ecological – Refers to the relationship between living things and their environment.

Economic – Of or relating to the production, development, and management of material

wealth, as of a country, household, or business enterprise.

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Ecosystem – An organic community of plants and animals viewed within its physical

environment (habitat); the ecosystem results from the interaction between soil, climate,

vegetation and animal life.

Ecosystem Restoration – activities that seek to return a organic community of plants and

animals and their habitat to a previously existing or improved natural condition or

function.

Effectiveness – Having an intended or expected effect. One of the USACE four

requirements for a project.

Efficiency – The quality of exhibiting a high ratio of output to input. One of the USACE

four requirements for a project.

Egress – A path or opening for going out; an exit.

Embankment – A linear mound of earth or stone existing or built to hold back water or

to support a roadway.

Encroachment –Entering gradually into an area not previously occupied, such as a plant

species distribution changing in response to environmental factors such as salinity.

Endangered Species – Animals and plants that are threatened with extinction.

Endpoints – see Objectives

Engineering News Record (ENR) – A magazine that provides news needed by anyone in

or from the construction industry.

Enhance – To augment or increase/heighten the existing state of an area.

Environmental Impact Statement (EIS) – A document that describes the positive and

negative environmental effects of a proposed action and the possible alternatives to that

action. The EIS is used by the federal government and addresses social issues as well as

environmental ones.

Estuary – A semi-enclosed body of water with freshwater input and a connection to the

sea where fresh water and salt water mix.

Estuarine – Related to an estuary.

Evaporation – The process by which any substance is converted from a liquid state into,

and carried off in, vapor; as, the evaporation of water.

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Exotic Species – Animal and plant species not native to the area; usually undesirable

(e.g., hyacinth, nutria, tallow tree, giant salvinia).

Faulting – A fracture in the continuity of a rock formation caused by a shifting or

dislodging of the earth's crust, in which adjacent surfaces are displaced relative to one

another and parallel to the plane of fracture.

Feasibility Report – A description of a proposed action previously outlined in a general

fashion in a Reconnaissance Report that will satisfy the Federal interest and address the

problems and needs identified for an area. It must include an assessment of impacts to

the environment (either in an Environmental Assessment, or the more robust

Environmental Impact Statement), an analysis of alternative methods of completion, and

the selection of a Recommended Plan through the use of a cost-effectiveness analysis.

Feature – A constructible increment of an alternative plan.

Federal Principals Group (FPG) – A collaboration among Federal agencies at the

Washington level to facilitate the flow of information, to provide guidance and

recommendations to the USACE and LDNR throughout the study process, and to

facilitate resolution of any interagency issues that may be identified in the conduct of the

study.

Final Array – The final grouping of the most effective coast-wide plans from which a

final recommendation can be made.

Fresh Marsh (FAM) – Intertidal herbaceous plant community typically found in that

area of the estuary with salinity ranging from 0–3 ppt.

Furbearer – An animal whose skin is covered with fur, especially fur that is

commercially valuable, such as muskrat, nutria, and mink.

Geomorphic – Related to the geological surface configuration.

Goals – Statements on what to accomplish and/or what is needed to address a problem

without specific detail.

Gradient – A slope; a series of progressively increasing or decreasing differences in a

system or organism.

Habitat – The place where an organism lives; part of physical environment in which a

plant or animal lives.

Habitat Loss – The disappearance of places where target groups of organisms live. In

coastal restoration, usually refers to the conversion of marsh or swamp to open water.

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Habitat Units (HUs) – Represent a numerical combination of quality (HIS) and quantity

(acres) existing at any given point in time. The HUs resulting from the future withoutand future with project scenarios are annualized, and averaged over the period of

analysis, to determine Average Annual Habitat Units (ASHUs). The “benefit” of a

project can be quantified by comparing AAHUs between the future without- and future

with-project scenarios. The difference is AAHUs between the two scenarios represents

the net benefit attributable to the project in terms of habitat quantity and quality.

Hazardous, Toxic, and Radioactive Wastes (HTRW) – Projects features must be

examined to ensure that their implementation will not result in excessive exposure to

pollutants possibly located in the study area.

Headland – A point of land projecting into the sea or other expanse of water, still

connected with the mainland.

Herbaceous – A plant with no persistent woody stem above ground.

Hydrodynamic – The continuous change or movement of water

Hydrology – The pattern of water movement on the earth's surface, in the soil and

underlying rocks, and in the atmosphere.

Indirect Impacts – Those effects that are not as a direct result of project construction,

but occur as secondary impacts due to changes in the environment brought about by the

construction. Contrast with “Direct Impacts.”

Infrastructure – The basic facilities, services, and installations needed for the

functioning of a community or society, such as transportation and communications

systems, water and power lines, and public institutions including schools, post offices,

and prisons.

Ingress – An entrance or the act of entering.

Inorganic – Not derived from living organisms; mineral; matter other than plant or

animal.

Interdistributary Deposits – Sand and mud deposited between the river channels or

between bayous.

Intermediate Marsh (INM) – Intertidal herbaceous plant community typically found in

that area of the estuary with salinity ranging from 2–5 ppt.

Intertidal – Alternately flooded and exposed by tides.

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Invertebrates – Animals without backbones, including shrimp, crabs, oysters, and

worms.

Land-water Ratio – The relative proportion or wetlands and uplands to water in an area.

Larvae – The stage in some animal’s life cycles between egg and adult (most

invertebrates).

Levee – A linear mound of earth or stone built to prevent a river from overflowing; a

long, broad, low ridge built by a stream on its flood plain along one or both banks of its

channel in time of flood.

Loamy – Soil composed of a mixture of sand, clay, silt, and organic matter.

Locally Preferred Plan (LPP) – Alternative plan preferred by local sponsor if other than

the Recommended Plan.

Maintain – To keep in existing state.

Measure – A programmatic restoration feature that can be assembled with other

measures to produce alternative plans. See also “Project.”

Methodology – A set of practices, procedures, and rules.

Mineral Substrate – Soil composed predominately of mineral rather than organic

materials; less than 20 percent organic material.

Mudflats – Flat, non-vegetated wetlands subject to periodic flooding and minor wave

action.

Myatt Series – Gray terrace soil, with whitish, pebbly subsoil.

National Ecosystem Restoration (NER) – USACE standard for cost-effectiveness based

on ecosystem, not economic, benefits.

National Environmental Policy Act (NEPA) – Ensures that Federal agencies consider

the environmental impacts of their actions and decisions. NEPA requires all Federal

agencies to consider the values of environmental preservation for all significant actions

and prescribes procedural measures to ensure that those values are fully respected.

Net Gain – The amount of cumulative land gain less land loss, when gain is greater than

loss.

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Net Loss – The amount of cumulative land gain less land loss, when gain is less than

loss.

No Action Alternative – The alternative in the LCA Plan which describes the ecosystem

of the coastal area if no restoration efforts/projects were done.

Nursery – A place for larval or juvenile animals to live, eat, and grow.

Objectives – More specific statements than “Goals,” describing how to achieve the

desired targets.

Organic – Composed of or derived from living things.

ppt – parts per thousand. The salinity of ocean water is approximately 35 ppt.

Prime Farmland – Land that has the best combination of physical and chemical

characteristics for producing food, feed, fiber, forage, oilseed, and other agricultural

crops with minimum inputs of fuel, fertilizer, pesticides, and labor, and without

intolerable soil erosion. One of the categories of concern in the EIS.

Principles – Framing statements that can be used to evaluate alternatives while

considering issues that affect them. Used along with targets and assessments of

ecosystem needs to provide guidance in formulation of alternative plans.

Productivity – Growth of plants and animals.

Programmatic Environmental Impact Statement (PEIS) – and Environmental Impact

Statement that supports a broad authorization for action, contingent on more specific

detailing of impacts from specific measures.

Project – A constructible increment of an alternative plan.

Project Implementation Report (PIR) – A project-specific follow-up report that

expands on the information contained in a Programmatic Feasibility Report to ensure

NEPA compliance, such as conducting public meetings, preparing the appropriate

environmental documentation, and preparing the engineering designs as specifications

necessary to build the project.

Province – A major division of the coastal zone of Louisiana. (e.g., Deltaic Plain and

Chenier Plain).

Pulsing – Letting a diversion flow periodically at a high rate for a short time, rather than

continuously.

Quantitative – Able to assign a specific number; susceptible to measurement.

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Radiocarbon Age Determination –The use of the ratio of carbon isotopes to determine

age.

Rebuild – To some extent build back a structure/landform that had once existed.

Reconnaissance Report – A document prepared as part of a major authorization that

examines a problem or need and determines if sufficient methods and Federal interest

exists to address the problem/need. If so, then a “Feasibility Report” is prepared, which

details the solution and its impacts further.

Reduce – To diminish the rate or speed of a process.

Rehabilitate – To focus on historical or pre-existing ecosystems as models or references

while emphasizing the reparation of ecosystem processes, productivity and service.

Relative Sea Level Rise – The sum of the sinking of the land (subsidence) and eustatic

sea level change; the change in average water level with respect to the surface.

Restore – Return a wetland to a close approximation of its condition or function prior to

disturbance by modifying conditions responsible for the loss or change; re-establish the

function and structure of that ecosystem.

Sangamonian Interglacial Period – the last interglacial period before the Holocene

period (the current geological period).

Saline Marsh (SAW) – Intertidal herbaceous plant community typically found in that

area of the estuary with salinity ranging from 12–32 ppt.

Salinity – The concentration of dissolved salts in a body of water, commonly expressed

as parts per thousand.

Salt Marshes – See “Saline Marsh.”

Scoping – Soliciting and receiving public input to determine issues, resources, impacts,

and alternatives to be addressed in the draft EIS.

Sea-Level – Long-term average position of the sea surface.

Sediment Plume – Caused by sediment rich rainwater runoff entering the ocean. The

runoff creates a visible pattern of brown water that is rich in nutrients and suspended

sediments that forms a kind of cloud in the water spreading out from the coastline.

Commonly forms at river and stream mouths, near sloughs, and along coasts where a

large amount of rain runoff flows directly into the ocean.

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Sheet Flow – Flow of water, sediment, and nutrients across a flooded wetland surface, as

opposed to through channels.

Shoaling – The shallowing of an open-water area through deposition of sediments.

Social – Relating to human society and its modes of organization.

Socioeconomic – Involving both social and economic factors.

Spoil Banks – Dredged material removed from canals and piled in a linear mound along

the edge of canals.

Stabilize – To fix the level or fluctuation of; to make stable.

State Historic Preservation Office (SHPO) – The part of the Louisiana Department of

Culture, Recreation, and Tourism that deals with Indian sites and other archaeological

remains.

Storm Surge – An abnormal and sudden rise of the sea along a shore as a result of the

winds of a storm.

Strategy – Ecosystem restoration concept from the Coast 2050 Plan.

Stream Gaging Data – Records of water levels in streams and rivers.

Submergence – Going under water.

Subprovince – The divisions of the two Provinces (see “Province”) into smaller

groupings: 1) east of the Mississippi River; 2) west of the Mississippi River to Bayou

Lafourche; 3) Bayou Lafourche to Freshwater Bayou; 4) Freshwater Bayou to Sabine

River.

Subsidence – The gradual downward settling or sinking of the Earth’s surface with little

or no horizontal motion.

Sustain – To support and provide with nourishment to keep in existence; maintain.

Tarbert Flow – Stream gage data recorded at Tarbert’s Landing on the Mississippi

River.

Target – A desired ecosystem state that meets and objective or set of objectives.

Terrestrial Habitat – The land area or environment where an organism lives; as distinct

from water or air habitats.

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Third Delta – A proposed project that would divert up to 120,000 cubic feet of water per

second from the Mississippi River near Donaldsonville, Louisiana down a conveyance

channel to the marshes in southern Barataria and Terrebonne Basins.

Turbidity – The level of suspended sediments in water; opposite of clarity or clearness.

Unique Farmland – Land other than Prime Farmland (see “Prime Farmland”) that is

used for the production of specific high-value food and fiber crops, such as citrus, tree

nuts, olives, cranberries, fruits, and vegetables.

Upland (UPL) – A general term for non-wetland elevated land above low areas along

streams or between hills.

Water Resource Units (WRU) – Stage-damage data developed as part of the Flood

Damage Estimation System (FDES) in 1980 for the Mississippi River and Tributaries

(MR&T) project were used to estimate the flood damages that are expected to occur in

Subprovinces 1, 2, and 3. The data collected for the FDES were delineated into

geographic areas with homogenous physical and hydraulic characteristics. These

geographic areas were numerically coded and designated as Water Resource Units

(WRUs). Within each WRU, land-use elements (structures, cropland, roads, bridges,

railroads, etc.) were categorized by location, value, and corresponding depth-damage

relationship. The structural damage categories included: residential, commercial,

industrial, public, and farm buildings.

Water Resources Development Act (WRDA) – A bill passed by Congress that provides

authorization and/or appropriation for projects related to the conservation and

development of water and related resources.

Weir – A dam placed across a canal or river to raise, divert, regulate or measure the flow

of water.

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9.5 Acronyms, Abbreviations, Symbols, and Initialisms

ASACW Assistant Secretary of the Army for Civil Works

ATR Agency Technical Review

CAA Clean Air Act

CE/ICA Cost Effectiveness/Incremental Cost Analysis

CEQ Council on Environmental Quality

CERCLA Comprehensive Environmental Response, Compensation, and Liability

Act (also known as Superfund)

CFR Code of Federal Regulations

cfs Cubic Feet per Second

CIAP Coastal Impact Assistance Program

CPRA Coastal Protection and Restoration Authority (State of Louisiana)

CWPPRA Coastal Wetlands Planning, Protection, and Restoration Act

CZM Coastal Zone Management

EA Environmental Assessment

EC Engineering Circular

EFH Essential Fish Habitat

EIS Environmental Impact Statement

EPA Environmental Protection Agency

ER Engineering Regulation

ESA Endangered Species Act

FHWA Federal Highway Administration

GIS Geographic Information System

GIWW Gulf Intracoastal Waterway

GMFMC Gulf of Mexico Fishery Management Council

HET Habitat Evaluation Team

HNC Houma Navigation Canal

HTRW Hazardous, Toxic, and Radioactive Waste

IWR Institute of Water Resources

LACPR Louisiana Coastal Protection and Restoration

LCA Louisiana Coastal Area (Ecosystem Restoration Study, 2004)

LDNR Louisiana Department of Natural Resources

LDWF Louisiana Department of Wildlife and Fisheries

LERRD Land, Easements, Rights-Of-Way, Relocation, and Disposal Areas

LEQA Louisiana Environmental Quality Act

LNHP Louisiana Natural Heritage Program

MR&T Mississippi River and Tributaries

MVD USACE Mississippi Valley Division

MVN USACE New Orleans District

MVS USACE St. Louis District

NAAQS National Ambient Air Quality Standards

NAVD North American Vertical Datum

NED National Economic Development

NEPA National Environmental Policy Act

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NER National Ecosystem Restoration

NGO Non-Governmental Organization

NGVD National Geodetic Vertical Datum

NHPA National Historic Preservation Act

NMFS National Marine Fisheries Service

NOAA National Oceanic and Atmospheric Administration

NOI Notice of Intent

NRCS Natural Resources Conservation Service

NRHP National Register of Historic Places

NWRC National Wildlife Research Center

O&M Operation and Maintenance

OMRR&R Operation and Maintenance, Repair, Replacement and Rehabilitation

PED Preconstruction Engineering and Design

PEIS Programmatic Environmental Impact Statement

PDT Project Delivery Team

RCRA Resource Conservation and Recovery Act

RP Recommended Plan

RSLR Relative Sea Level Rise

SLR Sea Level Rise

TSP Tentatively Selected Plan

USACE U.S. Army Corps of Engineers

USEPA U.S. Environmental Protection Agency

USFWS U.S. Fish and Wildlife Service

USGS U.S. Geological Survey

WCRF Wetlands Conservation and Restoration Fund

WVA Wetland Value Assessment

WRDA Water Resources Development Act

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Appendix-1

Volume III Appendices

APPENDIX A Biological Assessment

APPENDIX B U.S. Fish and Wildlife Service Coordination Letter and Report

APPENDIX C NOAA Fisheries Service Coordination Letter

APPENDIX D 404(b)(1) Water Quality Report

APPENDIX E Louisiana Coastal Resources Program Consistency Determination

APPENDIX F Cultural Resources with State Historic Preservation Officer

Coordination Letter

APPENDIX G Responses to Comments

FEASIBILITY REPORTS

APPENDIX H Value Engineering Report

APPENDIX I Adaptive Management / Monitoring Plan

APPENDIX J Real Estate Plan

APPENDIX K Economics

APPENDIX L Engineering

APPENDIX M Wetland Value Assessment (WVA) Model Report

APPENDIX N Phase I Environmental Site Assessment

APPENDIX O Micro-Computer Aided Cost Estimating System (MCACES)

Model Report / MCACES 2nd Generation (MII)

APPENDIX P Project Costs and Schedule Risk Analysis Report

APPENDIX Q Recreation Incidental Benefits

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MAIN REPORT

ATTACHMENT 1

Non-Federal Sponsor’s Letter of Intent

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Integrated Feasibility Study and Supplemental Environmental Impact Statement

For the

LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes and

Multipurpose Operation of Houma Navigation Lock St. Mary, Terrebonne, and

Lafourche Parishes, Louisiana

(APPENDICES A  Q)

The responsible lead Federal agency for this study is the U. S. Army Engineer District, New Orleans.

The Non-Federal Sponsor for the study is the Louisiana Coastal Protection and Restoration Authority.

The responsible cooperating Federal agency is the U.S. Fish and Wildlife Service

U.S. Army Corps of Engineers (USACE) and the Council of Environmental Quality(CEQ), and is

intended to reduce duplication and paperwork. An asterisk (*) in the table of contents notes

paragraphs that are required for National Environmental Policy Act (NEPA) compliance.

. This report is a

combined feasibility report and environmental impact statement complying with requirements of the

October 2010

Coastal Protection and

Restoration Authority

U.S Army Corps of Engineers

New Orleans District

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Biological Assessment

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Volume III

APPENDIX A:

Biological Assessment

Convey Atchafalaya River Water to Northern Terrebonne Marshes

And Multipurpose Operation of Houma Navigation Lock

1.0 PURPOSE................................................................................................................ 2

2.0 LOCATIONS AND GENERAL DESCRIPTION OF THE PROJECT AREA...... 2

3.0 PROPOSED ACTION............................................................................................. 6

4.0 SPECIES DESCRIPTIONS..................................................................................... 6

4.1 FISH......................................................................................................................... 6

4.2 BIRDS.................................................................................................................... 15

4.3 MAMMALS .......................................................................................................... 17

4.4 REPTILES ............................................................................................................. 19

5.0 POTENTIAL EFFECTS OF THE PROPOSED ACTION ................................... 26

5.1 FISH....................................................................................................................... 26

5.2 BIRDS.................................................................................................................... 27

5.3 MAMMALS .......................................................................................................... 27

5.4 REPTILES ............................................................................................................. 28

6.0 SUMMARY OF DETERMINATIONS ................................................................ 29

6.1 FISH....................................................................................................................... 29

6.2 BIRDS.................................................................................................................... 29

6.3 MAMMALS .......................................................................................................... 30

6.4 REPTILES ............................................................................................................. 30

7.0 LITERATURE CITED .......................................................................................... 31

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BIOLOGICAL ASSESSMENT

Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

1.0 PURPOSE

Consistent with Congressional direction provided in Title VII of the Water Resources

Development Act (WRDA) of 2007 authorizing the LCA program and Section

7006(e)(3), the U.S. Army Corps of Engineers (USACE), New Orleans District

(CEMVN) proposes to convey Atchafalaya River water to the Northern Terrebonne

Marshes. The purpose of this biological assessment (BA) is to evaluate the potential

impacts of the Recommended Plan (RP) described in the draft environmental impact

statement (DEIS) for Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock, on Federally-listed threatened

and endangered species, and their critical habitat. The RP includes features of wetland

nourishment, protection, and creation in the Northern Terrebonne Marshes. This BA

provides information to decision-makers to make determinations on whether to proceed

with the construction of the RP.

2.0 LOCATIONS AND GENERAL DESCRIPTION OF THE

PROJECT AREA

The LCA-ARTM Study Area (Figure 1.1) comprises approximately 1,100 square miles

(700,000 acres) in Southern Louisiana in the vicinity of the City of Houma and

Terrebonne Parish. The LCA-ARTM study area fits into the Louisiana Coastal Area

Ecosystem Restoration Study (LCA Study) Area, which has been identified as the

Louisiana coastal area from Mississippi to Texas. The proposed LCA-ARTM project is

located in the Deltaic Plain within Subprovince 3, one of the four Subprovinces identified

in the LCA Study Area.

The study area lies within the Barataria-Terrebonne estuary. This estuary extends from

the west bank levees of the Mississippi River (north and east), to the East Guide Levee of

the Atchafalaya River (west), to the Gulf of Mexico (south), and to the town of Morganza

(north). The Barataria Basin covers about 1,551,800 acres while the Terrebonne Basin

covers an area of about 2,063,500 acres. The study area lies within the southern end of

the Terrebonne Basin and contains a complex of habitat types, including natural levees,

lakes, swamps, marshes, and bayous formed from sediments of abandoned Mississippi

River deltas. Elevations in the study area vary. Near Houma, the largest city in the area,

the elevation is approximately 10 feet National Geodetic Vertical Datum (NGVD). The

elevation along the bayou ridges is 4-5 feet NGVD and less than 1 foot NGVD along the

southern portion near the Gulf of Mexico.

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Figure 1.1. Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of HoumaNavigation Lock Project Area.

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Figure 1.2. Features Associated with the Proposed Action.

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The major streams located in the study area or that influence the study area are the

Atchafalaya River, Bayou du Large, Bayou Grand Caillou, Bayou Petit Caillou, Bayou

Terrebonne, Bayou Pointe au Chien, Bayou Lafourche, Bayou Leau Blue, and Bayou

Black. There are no scenic streams in the study area designated under the Louisiana

Natural and Scenic River System. The Houma Navigation Canal runs north and south

from the GIWW to the Gulf of Mexico mainly between Bayou du Large and Bayou

Grand Caillou. The GIWW follows an east-west path in the northern portion of the study

area. These two waterways, along with the natural channels in the area, have a strong

influence on surface water in the area.

The natural processes of subsidence, habitat switching, and erosion, combined with

human activities, have caused significant adverse impacts to the Northern Terrebonne

Marshes, including accelerated wetland loss and ecosystem degradation.

Wetlands in the project area are deteriorating for several reasons: 1) subsidence, 2) lack

of sediment and nutrient deposition, 3) erosion via tidal exchange, 4) channelization, and

5) saltwater intrusion. These activities have resulted in the loss of several thousand acres

of solid, vegetated marsh. Deterioration will continue unless preventative measures are

taken.

In the absence of supplemental freshwater from the Atchafalaya River, subsidence, sealevel rise, wave erosion, and saltwater intrusion will continue to be problems. Protection

and enhancement of this area are dependent on providing a hydrologic regime that

minimizes the physiological stress to wetland vegetation from saltwater intrusion and

tidal energy and is conducive to the retention of locally provided freshwater and

sediments. Several channels have been dredged which cut through the natural ridges

increasing both drainage and tidal exchange in the project area, exposing the soil to

erosive forces.

The wetland communities within the northwestern portion of Terrebonne Basin,

including those located both north and south of the GIWW, have been, in part, separated

from the influence of the Atchafalaya River. Instead, the hydrology of these areas is

influenced by a widely variable pattern of Atchafalaya River backwater effect, rainfall

runoff events, and marine processes. Major navigation channels in the subprovince are

the Atchafalaya River, Wax Lake Outlet, Houma Navigation Canal, GIWW, and Lower

Atchafalaya River (south of Morgan City). Each of these navigation channels introduces

and/or compounds marine influences in many of the interior coastal wetlands and water

bodies within the subprovince. Without action, the freshwater, intermediate, and

brackish marshes in the northern and eastern areas of Terrebonne Basin would continue

to deteriorate and disappear due to the combined effects of subsidence, saltwater

intrusion, and a lack of riverine influence. To the south, the brackish marshes

surrounding Lake Mechant would continue to deteriorate due to saltwater intrusion and a

lack of riverine influence.

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3.0 PROPOSED ACTION

The proposed action consists of increasing freshwater flows and associated nutrients into

the project area. Project features designed to accomplish this (Figure 1.2) include

deepening and/or widening constrictions in the Gulf Intracoastal Waterway, placement of

a water control structure and dredge channel at the intersection of the GIWW and Grand

Bayou, placement of water control structures, dredging of conveyance channels, gapping

of spoil banks, and modification of the operation of the proposed Houma Navigation

Canal lock complex. The result of the proposed action would be protection and

nourishment of wetlands in the project area. When compared to the No Action

Alternative, the proposed action would prevent the loss of approximately 9,655 acres of

emergent marsh habitat over the 50-year period of analysis. According to the Wetland

Value Assessment conducted on the proposed action, the project would provide 3,220

Average Annual Habitat Units to project area marshes over the 50-year period of analysis

when compared to the No Action Alternative. A detailed description of the proposed

action can be found in Chapter 3 of the Draft Environmental Impact Statement/Feasibility

Study. Historic and existing conditions are discussed in Chapter 4. The future without

project conditions, direct, indirect, and cumulative impacts of the proposed action can be

found in Chapter 5.

4.0 SPECIES DESCRIPTIONS

Nine endangered or threatened species have been identified which may occur within the

boundaries of the project area: Gulf sturgeon (Acipenser oxyrhynchus desotoi), pallid

sturgeon (Scaphirhynchus albus), piping plover (Charadrius melodus), West Indian

manatee (Trichechus manatus) and five species of sea turtles. Descriptions of these

species follow.

4.1 FISH

4.1.1 Gulf Sturgeon

Status

On September 30, 1991, the Gulf sturgeon was listed as a threatened species under the

ESA, and the USFWS designated critical habitat for this species throughout its range on

February 28, 2003. In Louisiana, Gulf sturgeon critical habitat includes the Pearl River

System in Washington and St. Tammany Parishes, the Bogue Chitto River, as well as

Lake Pontchartrain, Lake Borgne, Lake Catherine, and the Rigolets.

Species and Habitat Description

The Gulf sturgeon, also known as the Gulf of Mexico sturgeon, is an anadromous fish

(i.e. a fish that breeds in freshwater after migrating from marine or estuarine

environments). The Gulf sturgeon inhabits coastal rivers from Louisiana to Florida during

spring and summer, and the estuaries, bays, and marine environments of the Gulf of

Mexico during fall and winter. It is a nearly cylindrical, primitive fish embedded with

bony plates or scutes. The head ends in a hard, extended snout; the mouth is inferior and

protrusible and is preceded by four conspicuous barbels. The tail (caudal fin) is distinctly

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asymmetrical; the upper lobe is longer than the lower lobe (heterocercal). Adults range

from 4 to 8 feet (1.2 to 2.4 meters) in length, with adult females larger than adult males.

Gulf sturgeon are long-lived, with some individuals reaching at least 42 years of age

(Huff 1975). Age at sexual maturity for females ranges from 8 to 17 years, and for males

from 7 to 21 years (Huff 1975). In the spring (from late February to mid-April) when the

river surface temperatures are 63 to 70 degrees Fahrenheit (oF) (17 to 21 degrees Celsius

[oC]), sexually mature males and females migrate into rivers to spawn (Carr et al. 1996).

It is believed that Gulf sturgeon exhibit a spawning periodicity similar to Atlantic

sturgeon, with females spawning at intervals ranging from every 3 to 5 years, and males

every 1 to 5 years (Smith 1985, see http://www.fws.gov).

Gulf sturgeon eggs are demersal (i.e. they sink to the bottom), adhesive, and vary in color

from gray to brown to black (Vladykov and Greeley 1963; Huff 1975; Parauka et al.

1991). Sturgeon require hard substrates for eggs to adhere to and to provide shelter for

developing larvae (Sulak and Clugston 1998, see http://www.fws.gov). Egg collection

sites have consisted of limestone bluffs and outcroppings, cobble, limestone bedrock

covered with gravel, and small cobble, gravel, and sand (Marchant and Shutters 1996, see

http://www.fws.gov; Sulak and Clugston 1999, see http://www.fws.gov; Heise et al.

1999a, see http://www.fws.gov; Fox et al. 2000, see http://www.fws.gov; Craft et al.

2001, see http://www.fws.gov). Water depths at egg collection sites ranged between 4.6

to 26 ft (1.4 to 7.9 m), and temperatures ranged around 64.8 to 75.0o

F (18.2 to 23.9oC)

(Fox et al. 2000; Ross et al. 2000; Craft et al. 2001; Heise et. al. 2004). Laboratory

experiments indicate that optimal water temperature for survival of Gulf sturgeon larvae

is between 59 and 68oF (15 and 20oC), with low tolerance to temperatures above 77oF

(25oC) (Chapman and Carr 1995, see http://www.fws.gov). Young-of-the-year Gulf

sturgeon appear to disperse widely, using extensive portions of the river as nursery

habitat. They are typically found on sandbars and sand shoals over rippled bottom and in

shallow, relatively open, unstructured areas.

Gulf sturgeon feeding habits in freshwater vary depending on the fishs life history stage.

Young-of-the-year Gulf sturgeon remain in freshwater feeding on aquatic invertebrates

and detritus approximately 10 to 12 months after spawning occurs (Mason and Clugston

1993; Sulak and Clugston 1999, see http://www.fws.gov). Juveniles less than 11 lbs (5

kg) are believed to forage extensively and exploit scarce food resources throughout the

river, including aquatic insects (e.g., mayflies and caddis flies), worms (oligochaetes),

and bivalve mollusks (Huff 1975; Mason and Clugston 1993). Subadults (age 6 to sexual

maturity) and adults (sexually mature) only feed in marine and estuarine habitats and are

thought to forage opportunistically (Huff 1975) on primarily benthic (bottom dwelling)

invertebrates. Gut content analyses have indicated that, at this life stage, the Gulf

sturgeons diet is predominantly amphipods, lancelets, polychaetes, gastropods, shrimp,

isopods, mollusks, and crustaceans (Huff 1975; Mason and Clugston 1993; Carr et al.

1996b, see http://www.fws.gov; Fox et al. 2000, see http://www.fws.gov; Fox et al. 2002,

see http://www.fws.gov).

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Gulf sturgeon are believed to be indiscriminate benthic suctorial feeders (Gilbert 1989).

Summaries of food habits data (Huff 1975; Mason and Clugston 1993, USFWS/GSMFC

1995; Wakeford 2001; Fox et al. 2002; Harris 2003) indicate that this species feeds on a

wide variety of benthic prey. Examining the stomach contents of fish from the Suwannee

River estuary, Mason and Clugston (1993) found the predominant prey of subadults to be

brackish water amphipods (Gammarus sp. and haustorid amphipods), corophoiid

amphipods (e.g., Cerapus sp. and Corophium tuberculatum), chironomid and

ceratopogonid fly larvae, grass shrimp (Palaemonetes spp.), and mysid shrimp.

Polychaetes and tubificid oligochaetes were also plentiful in the diet. Subadults fed on

grass shrimp and the callianassid shrimp Lepidophthalmus louisianensis. Fish

immigrating from offshore had lancelets (Branchiostoma caribaeum), brachiopods

(Glottidia pyramidata), shrimp, polychaetes, molluscs, starfish and sea cucumbers in the

stomachs. Also working in the Suwannee River estuary, Harris (2003) indicated that

brachiopods were particularly important in the diet of gulf sturgeon although amphipods

(Ampelisca spp.) and brittlestars (ophiouroids) were also frequent prey items. Based on

these reports, especially those emphasizing the importance of brachiopods, lancelets,

haustorid amphipods and the callianassid L. louisianensis, it would appear that sturgeon

favor sandy bottomed areas for feeding.

When river temperatures drop in the fall to about 63 to 72o

F (17 to 22oC), Gulf sturgeon

return to the coastal shelf areas of the Gulf of Mexico (Carr et al. 1996, see

http://www.fws.gov). Most subadult and adult Gulf sturgeon spend the cooler months

(October or November through March or April) in estuarine areas, bays, or the Gulf of

Mexico feeding (Odenkirk 1989; Foster 1993; Clugston et al. 1995; Fox et al. 2002, see

http://www.fws.gov). Winter habitats used by Gulf sturgeon coincide with the habitats of

their prey. Along the Mississippi Sound barrier islands, Gulf sturgeon habitat typically

consists of sandy substrates with an average depth of 6.2 to 19.4 ft (1.9 to 5.9 m). Gulf of

Mexico near shore (less than 1 mi [1.6 km]) unconsolidated, fine-medium grain sand

habitats, including natural inlets and passes from the Gulf to estuaries, support

crustaceans such as mole crabs, sand fleas, various amphipod species, and lancelets

(Menzel 1971, see http://www.fws.gov; Abele and Kim 1986, see http://www.fws.gov;

American Fisheries Society 1989, see http://www.fws.gov; Brim, personal

communication, 2002) where Gulf sturgeon are found. Estuary and bay unvegetated

habitats have a preponderance of sandy substrates that support burrowing crustaceans,

such as ghost shrimp, small crabs, various polychaete worms, and small bivalve mollusks

(Menzel 1971, see http://www.fws.gov; Abele and Kim, 1986, see http://www.fws.gov;

American Fisheries Society, 1989, see http://www.fws.gov) which are prey for Gulf

sturgeon. Bony fish are seldom consumed. Detritus, both inorganic and organic, is

consumed incidentally by Gulf sturgeon of all sizes as they feed on various prey (Mason

et al. 1993, in USACE 2006). Non-spawning sturgeon appear to feed longer in the

estuaries and bays prior to moving into the rivers than spawning adults (Fox et al. 2000,

in USACE 2006).

Range and Population Dynamics

Historically, the Gulf sturgeon occurred from the Mississippi River east to Tampa Bay.

Its present range extends from Lake Pontchartrain and the Pearl River system in

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Louisiana and Mississippi, east to the Suwannee River in Florida (Wooley 1985), with

infrequent sightings occurring west of the Mississippi River. In the late 19th century and

early 20th century, the Gulf sturgeon supported an important commercial fishery,

providing eggs for caviar, flesh for smoked fish, and swim bladders for isinglass, a

gelatin used in food products and glues (Huff 1975; Carr 1983). Gulf sturgeon numbers

declined due to over fishing throughout most of the 20th century. After 1950, the decline

was exacerbated by habitat loss associated with the construction of water control

structures, such as dams and sills (submerged ridges or vertical walls of relatively

shallow depth separating two bodies of water). In several rivers throughout the species

range, dams have severely restricted sturgeon access to historic migration routes and

spawning areas (Boschung 1976; Wooley and Crateau 1985; McDowall 1988). Gulf

sturgeon exhibit a high degree of fidelity, with over 99 percent returning to spawn in the

same river system in which they were hatched (USACE 2006).

The majority of recent Gulf sturgeon sightings in the Pearl River drainage have occurred

downstream of the Pools Bluff Sill near Bogalusa, Louisiana, and downstream of the

Bogue Chitto Sill on the Bogue Chitto River in St. Tammany Parish, Louisiana. Between

1992 and 1996, 257 Gulf sturgeon were captured from the Pearl River system (West

Middle River, Bogue Chitto River, East Pearl River, and West Pearl River). The

subpopulation in that system was estimated at 292 fish, of which only 2 to 3 percent were

adults (Morrow et al. 1998b, see http://www.fws.gov). The annual mortality rate was

calculated to be 25 percent.

Preliminary results from captures between 1992 and 2001 suggest a stable subpopulation

of 430 fish, with approximately 300 adults (Rogillio et al. 2002, see http://www.fws.gov).

Morrow et al. (1999, see http://www.fws.gov) suggested that the Pearl River Gulf

sturgeon population would be self-sustaining if the number of adults was at least 100,

recruitment was satisfactory, and annual mortality was less than about 15 percent. Based

on those criteria and from data gathered during 2000 and 2001, it appears that the

population is at least self-sustaining and may even be recovering. There may be as many

as 300 adults. While mortality estimates may be somewhat biased, the rate is probably

about half of the 15 percent deemed to be a minimum acceptable benchmark.

Management and Protection

Life history characteristics of Gulf sturgeon may complicate and protract recovery

efforts. Gulf sturgeon cannot establish a breeding population rapidly because of the

amount of time it takes them to reach sexual maturity. Further, Gulf sturgeon appear to

be river-specific spawners, although immature Gulf sturgeon occasionally exhibit

plasticity in movement from one river to another. Therefore, natural repopulation by

Gulf sturgeon migrating from other rivers may be non-existent or very low.

The take of Gulf sturgeon is prohibited in the state waters of Louisiana, Mississippi,

Alabama, and Florida. Section 6(a) of the ESA provides for extended cooperation with

states for the purpose of conserving threatened and endangered species. Under that

provision, the Departments of the Interior and Commerce may enter into cooperative

agreements with a state, provided that state has an established program for the

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conservation of a listed species. The agreements authorize the states to implement the

authorities and actions of the ESA relative to the listed species recovery. Specifically, the

states are authorized: 1) to conduct investigations to determine the status and

requirements for survival of resident species of fish and wildlife (this may include

candidate species for listing), and 2) to establish programs, including acquisition of land

or aquatic habitat or interests for the conservation of fish and wildlife. Federal funding is

also provided to states under those agreements to implement the approved programs. All

four of the above mentioned states have entered into Section 6 agreements with the

USFWS.

4.1.2 Pallid Sturgeon

Status

The pallid sturgeon was listed as endangered on October 9, 1990. The reasons for listing

were habitat modification, apparent lack of natural reproduction, commercial harvest, and

hybridization in parts of its range. Critical habitat has not been proposed or designated

for the pallid sturgeon.

Species and Habitat Description

Pallid sturgeon evolved from an ancient group of bony fishes, the subclass Paleopterygii.

Most species in this subclass became extinct sometime in the Mesozoic Era. The living

descendants of this group in North America include paddlefish and eight species of

sturgeon.

The pallid sturgeon grows to lengths of over 6 feet, can weigh in excess of 80 pounds,

and has a flattened, shovel-shaped snout, a long, slender, and completely armored caudal

peduncle, and lacking a spiracle (Smith 1979). As with other sturgeon, the mouth is

toothless, protrusible, and ventrally positioned under the snout. The skeletal structure is

primarily cartilaginous (Gilbraith et al. 1988).

Forbes and Richardson (1905), Schmulbach et al. (1975), Kallemeyn (1983), and

Gilbraith et al. (1988) describe the pallid sturgeon as being well adapted to life on the

bottom in swift water of large, turbid, free-flowing rivers. Pallid sturgeon evolved in the

diverse environments of the Missouri and Mississippi Rivers. Floodplains, backwaters,

chutes, sloughs, islands, sandbars, and main channel waters formed the large-river

ecosystem that provided macrohabitat requirements for pallid sturgeon and other native

large-river fish, such as paddlefish and other sturgeon. Those habitats were historically

in a constant state of change. Mayden and Kuhajda (1997) describe the natural habitat

conditions to which pallid sturgeon are adapted as braided channels, irregular flow

patterns, flooding of terrestrial habitats, extensive microhabitat diversity, and turbid

waters. Those habitat conditions and much of the once naturally functioning ecosystem

have been changed by human activities.

Bramblett (1996) noted important aspects of pallid sturgeon habitat use and movements.

He also noted that the pallid sturgeon is specific and restrictive in use of macrohabitat

selection. According to Brambletts (1996) study, pallid sturgeon were found most often

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in sinuous channels with islands or alluvial bars present. Straight channels, and channels

with irregular patterns or irregular meanders were only rarely used by pallid sturgeon.

The seral stage of islands or bars near pallid sturgeon occurrences was most often

subclimax (Bramblett 1996). Bramblett (1996) found macrohabitats used by pallid

sturgeon were diverse and dynamic. For example, pallid sturgeon used river reaches with

sinuous channel patterns and islands and alluvial bars; those river reaches generally have

more diverse depths, current velocities, and substrates than do relatively straight channels

without islands or alluvial bars, as well as a high diversity of channel features such as

backwaters and side channels. The subclimax riparian vegetational seres in those areas

are indicative of a dynamic river channel and riparian zone (Johnson 1993).

In telemetry studies of pallid sturgeon on the middle Mississippi River, Sheehan et al.

(1998) found a positive selection for main channel border and downstream islands tips,

depositional areas between wing dams, and deep holes off wing dam tips. Sheehan et al.

(1998) speculated that areas between wing dams and downstream island tips may be used

as velocity refugia and/or feeding stations. Sturgeon were found most often in main

channel habitat; however, they exhibited selection against that habitat type. Their

occurrence in such habitat was not surprising, considering main channel habitat

comprised approximately 65 percent of the available habitat in the study reach (Sheehan

et al. 1998).

Constant et al. (1997) reported on radio-tracked sturgeon, and stated that sturgeon were

most frequently found in low-slope areas and that such areas were used in proportion to

their availability. No sturgeon were observed on extremely steep slopes. Constant et al.

(1997) found that sand made up over 80 percent of the substrate in low-slope areas where

over 90 percent of pallid sturgeon were located. Those authors stated that the preference

for sand substrates in lowslope areas suggests that pallid sturgeon use such areas as

current refugia. Sand substrates were found to have lower invertebrate densities than

substrates of silt-clay, which were generally located on steep-slope areas that were

exposed by swift currents. As such, it would have been energetically costly for pallid

sturgeon to remain near those steep-slope areas for extended periods of time. Telemetry

observations, however, showed that 55 percent of sturgeon locations occurred within 33

feet of steep slopes, suggesting that pallid sturgeon remained near areas of high food

abundance (Constant et al. 1997). Reed and Ewing (1993) found sturgeon occurring in

the man-made riprap lined outfall channels of the Old River Control Structure Complex

(ORCSC) in Louisiana. Bramblett (1996) found that pallid sturgeon preferred sandy

substrates, particularly sand dunes, and avoided substrates of gravel and cobble. Pallid

sturgeon have adhesive eggs. Thus, spawning is thought to occur over hard substrates of

gravel or cobble with moderate flow (USFWS 2000).

Caution must be used in interpreting the results of habitat preference studies conducted in

todays highly altered river environments. The results of studies conducted by Bramblett

(1996) under fairly unaltered riverine conditions, however, provide additional

information on habitat conditions preferred by this species. Characteristics of

microhabitat used by pallid sturgeon have recently been described. Much of the

microhabitat research to date has been conducted in significantly altered environments.

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That research does not necessarily indicate preferred or required habitats; instead it may

only indicate which habitats of those presently available the pallid sturgeon uses. Also,

capture locations may have conditions representing seasonal habitat preferences. Hurley

(1996) found that pallid sturgeon were selecting downstream island tips although the

island tips were not abundant within the study area. Constant et al. (1997) found pallid

sturgeon in the Atchafalaya and Mississippi Rivers at mean depths of 49.9 feet and

observed pallid sturgeon at depths of 23.0 and 68.9 feet with greater frequency than such

areas were available. The range of depth used by pallid sturgeon is likely related to the

available habitat within the river segment (USFWS 2000).

Pallid sturgeon spawning occurs from March through July depending on location (Forbes

and Richardson 1905; Gilbraith et al. 1988). Keenlyne and Jenkins (1993) estimate that

spawning probably begins in March in the lower Mississippi and Atchafalaya Rivers; in

late April or early May in the lower Missouri and middle Mississippi Rivers; and in late

May or early June in the upper Missouri River.

All sturgeon species spawn in the spring or early summer, are multiple spawners, and

release their eggs at intervals. In the wild, the adhesive eggs are released in deep

channels or rapids and are left unattended (Gilbraith et al. 1988). The larvae of

Acipenserids are generally pelagic, becoming buoyant or active immediately after

hatching (Moyle and Cech 1982). Although the behavior of young pallid sturgeon is

poorly understood, work by Kynard et al. (1998) indicates that a downstream migration

period for larval pallid sturgeon begins at hatching and continues up to day 13. With this

information it has been possible to use water velocities to roughly estimate that larval

pallid sturgeon may drift in the water column for a distance of 40 to over 400 miles

(USFWS 2000).

Although benthic macroinvertebrates, characteristic of river habitats, are important pallid

sturgeon dietary components (Modde and Schmulbach 1977; Carlson et al. 1985), the

occurrence of lake and terrestrial invertebrates in sturgeon stomachs suggest that drifting

invertebrates may also be important forage organisms (Modde and Schmulbach 1977;

Constant et al. 1997). Aquatic invertebrates (principally the immature stages of insects)

compose most of the diet of shovelnose sturgeon, while adult pallid sturgeon and hybrids

consume a greater proportion of fish (mostly cyprinids). Other researchers also reported

a higher incidence of fish in the diet of adult pallid sturgeon than in the diet of shovelnose

sturgeon (Cross 1967; Held 1969).

Range and Population Dynamics

The pallid sturgeon is endemic to the Yellowstone, Missouri, Middle and Lower

Mississippi Rivers, and the lower reaches of their major tributaries. Within Louisiana,

the pallid sturgeon is found in both the Mississippi and Atchafalaya Rivers (with known

concentrations in the vicinity of the ORCSC); it is possibly found in the Red River as

well. The historic range of pallid sturgeon, as described by Bailey and Cross (1954),

encompassed the middle and lower Mississippi River, the Missouri River, and the lower

reaches of the Platte, Kansas, and Yellowstone Rivers. Duffy et al. (1996) stated that the

historic range of pallid sturgeon once included the Mississippi River upstream to Keokuk,

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Iowa, before the river was converted into a series of locks and dams for commercial

navigation (Coker 1930).

The pallid sturgeon appears nearly extirpated from large segments of its former range. In

1991, pallid sturgeon were discovered in the Atchafalaya River in Louisiana (Constant et

al. 1997). Today, they are only occasionally found in a few selected areas. Since 1980,

reports of most frequent occurrence are from the Missouri River, the Mississippi River,

and the Atchafalaya River at the ORCSC (USFWS 1993). Of 872 pallid sturgeon records

prior to 1998, 70 percent were reported from the Missouri River. Nine percent of the

total records came from the Yellowstone River, 5 percent from the Mississippi River, 14

percent from the Atchafalaya River, and less than 2 percent from the St. Francis, Platte,

Ohio, Kansas, and Big Sunflower Rivers (USFWS 2000). Keenlyne (1989) updated

previously published and unpublished information on distribution and abundance of

pallid sturgeon.

The Missouri River has been modified significantly, with approximately 36 percent of the

riverine habitat inundated by reservoirs, 40 percent channelized, and the remaining 24

percent altered due to dam operations (USFWS 1993). Most of the major tributaries of

the Missouri and Mississippi Rivers have also been altered to various degrees by dams,

water depletions, channelization, and riparian corridor modifications.

Levee construction on the lower Mississippi River from the Ohio River to near the Gulf

of Mexico has eliminated the rivers major natural floodway and reduced the area of the

floodplain connected to the river by more than 90 percent (Fremling et al. 1989).

Fremling et al. (1989) also reported that levee construction isolated many floodplain

lakes and raised riverbanks. Destruction and alteration of big-river ecologic functions

and habitat once provided by the Missouri and Mississippi Rivers is believed to be the

primary cause of declines in reproduction, growth, and survival of pallid sturgeon

(USFWS 1993). In spite of efforts to constrict and control the Missouri and Mississippi

Rivers with reservoirs, stabilized banks, jetties, dikes, levees, and revetments, remnant

reaches of the Missouri River and Mississippi River from the Missouri River confluence

to the Gulf of Mexico still provide habitat usable by pallid sturgeon for certain life stages.

Since 1988, pallid sturgeon researchers have collaborated on studies to gather

information about the species (Keenlyne 1995). Tag and recapture data indicate that 50

to 100 pallid sturgeon remain in the Missouri River above Fort Peck Dam in Montana,

and between 200 and 300 pallid sturgeon remain between the Garrison Dam in North

Dakota and Fort Peck Dam, including the lower Yellowstone River (USFWS 2000). One

to five pallid sturgeon sightings per year have been recorded between the headwaters of

Oahe Reservoir in South Dakota to the Garrison Dam and from the riverine reach in the

Missouri River above Gavins Dam to Fort Randall Dam, suggesting that perhaps as many

as 25 to 50 pallid sturgeon may remain in each of these areas. A small population also

exists between Oahe Dam and Big Bend Dam on the Missouri River in South Dakota

with perhaps 50 to 100 individuals remaining in that riverine section. There is no

evidence that the upper Missouri River system populations are successfully reproducing

(Keenlyne 1989; Duffy et al. 1996).

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Glen Constant, while conducting research at Louisiana State University, estimated the

pallid sturgeon population in the Atchafalaya River to range from 2,750 to 4,100 fish. A

high rate of hybridization is occurring in the Atchafalaya and Mississippi Rivers

(Keenlyne et al. 1994); that makes estimation of the number of pure pallid sturgeon in

those river systems difficult (Duffy et al. 1996).

In recent years, pallid sturgeon populations have been augmented by release of hatcheryreared fish. In 1994, the Missouri Department of Conservation (MDC) released

approximately 7,000 fingerlings in the Missouri and Mississippi Rivers, and an additional

3,000 fingerlings were stocked in 1997 (Graham 1997, 1999). Since stocking in 1994,

approximately 86 pallid sturgeon returns have been reported, mostly in the Mississippi

River downstream of St. Louis (Graham 1999). Thirty-five 12- to 14-inch pallid sturgeon

raised at Natchitoches NFH were stocked in the lower Mississippi River in 1998

(Kilpatrick 1999). Also in 1998, 745 hatchery-reared yearling pallid sturgeon were

released at three sites in the Missouri River above Fort Peck Reservoir (Gardner 1999)

and another 750 yearling sturgeon were released near the confluence of the Yellowstone

and Missouri Rivers (USFWS 2000).

Evidence of successful pallid sturgeon reproduction is rare throughout the range of the

species. Recent work in the Atchafalaya River has revealed pallid sturgeon of several

age groups, suggesting that some reproduction and recruitment may also occur in the

Atchafalaya River. The only physical evidence of reproduction, however, were three

gravid females reported by Constant et al. (1997). According to their data, pallid

sturgeon collected in the Atchafalaya River and other areas of the Mississippi River have

averaged less than 6.6 pounds and length-at age estimates calculated according to Fogle

(1963) indicated that even the smallest fish were over age 6, with the oldest perhaps over

age 14. The age of fish in their study indicates the most recent recruitment of pallid

sturgeon to be from the 1988-year class (Constant et al. 1997).

Management and Protection

Habitat destruction and alteration is believed to be the primary cause of declines in pallid

sturgeon reproduction, growth, and survival. It is unlikely that successfully reproducing

pallid sturgeon populations can be recovered without restoring the habitat elements

(morphology, hydrology, temperature regime, cover, and sediment/organic matter

transport) of the Missouri and Mississippi Rivers necessary for the species continued

survival (USFWS 1993). In spite of efforts to control the Missouri and Mississippi

Rivers with reservoirs, stabilized banks, jetties, dikes, levees, and revetments, remnant

reaches of the Missouri and Mississippi Rivers still provide habitat believed to be usable

by the pallid sturgeon. Those habitat remnants are priority areas for implementation of

recovery actions (USFWS 1993).

Mortality of pallid sturgeon occurs from both sport and commercial fishing activities.

The states of North Dakota, South Dakota, and Louisiana require the release of all

sturgeon whether taken commercially or for sport. Neither Montana nor Kansas allow

commercial harvest of sturgeon. Sturgeon continued to be harvested as a bycatch of

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commercial fishing operations in Nebraska, Iowa, Missouri, Illinois, Kentucky,

Tennessee, Arkansas, and Mississippi (USFWS 1993).

Pollution is also a likely threat to the pallid sturgeon over much of its range. Further

investigations are needed to identify sources of contaminants in the Missouri and

Mississippi Rivers, and to assess the role of contaminants in the decline of pallid sturgeon

populations (USFWS 1993).

The pallid sturgeon is known to hybridize with the shovelnose sturgeon (Carlson et al.

1985). Keenlyne et al. (1992) concluded that hybridization might be occurring in half of

the river reaches within the pallid sturgeons range. Hybridization may be related to

environmental degradation. Presumably, the loss of habitat diversity caused by humaninduced environmental changes inhibits the reproductive isolating mechanisms that

naturally occur among fish species. Also, the loss of available spawning habitat forces

sharing of suitable habitat areas by similar species, with resultant increased hybridization

(USFWS 1993).

4.2 BIRDS

4.2.1 Piping Plover

Status

On January 10, 1986, the piping plover was Federally listed as endangered in the Great

Lakes watershed, and as threatened elsewhere in its range. Critical habitat for the

wintering population was designated in 2001; that designation included 142 areas along

the coast of North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi,

Louisiana, and Texas, to provide sufficient wintering habitat to support the piping plover

at the population level and geographic distribution necessary for recovery of the species.

Critical habitat for breeding populations in the Great Lakes and Great Plains was

designated in 2001 and 2002, respectively.

Species and Habitat Description

The piping plover, named for its melodious mating call, is a small North American

shorebird approximately 8 inches long with a wingspread of about 15 inches (Palmer

1967). Its light sandcolored plumage blends in well with beaches and sand flats, part of

its primary habitat. During the breeding season, the legs are bright orange, and the short

bill is orange with a black tip. There are two single dark bands, one around the neck and

one across the forehead between the eyes. The black breast band and brow bar are

generally more pronounced in breeding males than females (Wilcox 1959). Breeding

birds have white underparts, a light beige back and crown, a white rump, and a black

upper tail with a white edge. In flight, each wing shows a single, white wing stripe with

black highlights at the wrist joints and along the trailing edges. In winter, the bill turns

black, the legs remain orange but pale, and the black plumage bands are lost on the head

and neck. Chicks have speckled gray, buff, and brown down, a black beak, orange legs,

and a white collar around the neck. Juveniles resemble wintering adults and obtain their

adult plumage the spring after they fledge (Prater et al. 1977). The primary constituent

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elements for piping plover critical habitat (wintering) are found in geologically dynamic

coastal areas that contain intertidal beaches and flats (between annual low tide and annual

high tide), associated dune systems, and flats above annual high tide. Primary constituent

elements of intertidal flats include sand and/or mud flats with no or very sparse emergent

vegetation. Adjacent unvegetated or sparsely vegetated sand, mud, or algal flats above

high tide are also important for roosting plovers (USFWS 2002). Northward migration to

the breeding grounds occurs during late February, March and early April (Patterson 1988;

MacIvor 1990). Plovers will breed at 1 year of age (MacIvor 1990; Strauss 1990; Haig

1992) and are monogamous, but usually shift mates between years (Wilcox 1959; Haig

and Oring 1988; MacIvor 1990). Southward migration to the wintering grounds along

the southern Atlantic coast and Gulf of Mexico shoreline extends from late July through

September. Individuals can be found on their wintering grounds throughout the year but

sightings are rare in May, June, and early July (USFWS 2001b). In general, wintering

piping plovers feed extensively on intertidal beaches, mudflats, sand flats, algal flats, and

wash-over passes with no or very sparse emergent vegetation; they also require

unvegetated or sparsely vegetated areas for roosting. Roosting areas may have debris,

detritus, or micro-topographic relief offering refuge to plovers from high winds and cold

weather. In most areas, wintering piping plovers are dependent on a mosaic of sites

distributed through the landscape, as the suitability of a particular site for foraging or

roosting is dependent on local weather and tidal conditions. Plovers move among sites as

environmental conditions change. The following units are designated critical habitat in

Louisiana: (1) Texas/Louisiana border to Cheniere au Tigre in Cameron and Vermilion

Parishes; (2) Atchafalaya River Delta in St. Mary Parish; (3) Point Au Fer Island in

Terrebonne Parish; (4) Isles Dernieres in Terrebonne Parish; (5) Timbalier Island to East

Grand Terre Island in Terrebonne, Lafourche, Jefferson, and Plaquemines Parishes; (6)

Mississippi River Delta in Plaquemines Parish, and (7) Breton Islands and Chandeleur

Island Chain in Plaquemines and St. Bernard Parishes (see 50 CFR Part 17, pages 36127

to 36131, or http://plover.fws.gov/#maps, for detailed descriptions and/or maps).

Range and Population Dynamics

Piping plovers breed only in North America within three geographic regions

encompassing three distinct breeding populations: the Northern Great Plains, the Great

Lakes, and the Atlantic Coast. The piping plovers primary winter range is along the

Atlantic and Gulf coasts from North Carolina to Mexico and into the Bahamas and West

Indies (USFWS 1988, 1989a, 1989b, 1996, 2002). Loss and degradation of habitat due to

development and shoreline stabilization have been major contributors to the species

decline. Recreational activity, coastal development, and dune stabilization have resulted

in loss of suitable sandy beaches and other littoral habitats. Breeding success continues

to be affected by human disturbance (foot and vehicular traffic), which destroys nests and

young (USFWS 1989b, 1996). Since piping plovers spend 55 to 80 percent of their

annual cycle associated with wintering areas, factors that affect their well being on the

wintering grounds can substantially affect their survival and recovery (USFWS 1996).

Between 1986 and 1987, there were an estimated 1,258 to 1,326 breeding pairs of piping

plovers in the Northern Great Plains breeding population. The 1991 International Piping

Plover Census estimated that there were 1,486 breeding pairs in the Northern Great

Plains. The 1996 census for that population indicated that it numbered about 3,284

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adults, which would be the largest of the three breeding populations (i.e., Northern Great

Plains, Great Lakes, and Atlantic Coast). Russell (1983) reviewed historic records and

estimated pre-settlement Great Lakes piping plover populations at 492 to 682 breeding

pairs; those totals may be high, but there are no other estimates of pre-settlement

population. Coinciding with major industrial development, piping plovers were

extirpated from most of the Great Lakes beaches in the late 1970s and early 1980s. In

1977, the Great Lakes population was estimated at 31 nesting pairs (Lambert and Ratcliff

1979), but declined to 17 pairs by 1985 (USFWS 1985). Since 1986, nests have been

recorded at 30 breeding sites with populations ranging from 12 to 25 breeding pairs.

Historical trends for the Atlantic Coast piping plover population have been gathered from

largely qualitative records. In the nineteenth century, piping plovers were a common

summer resident along the Atlantic Coast; by the twentieth century, uncontrolled hunting

and egg collecting greatly reduced their populations. Following the passage of the

Migratory Bird Treaty Act in 1918, piping plover numbers recovered to some extent.

Raithel (1984) showed that Rhode Island piping plover numbers reached a twentieth

century peak following a 1938 hurricane, which flattened sand dunes and shoreline

developments. After World War II, populations declined due to dune stabilization efforts

and construction of summer homes. The population partially recovered following

another severe hurricane in 1954, but then began a decline that continued through the

early 1980s. Recent population estimates indicate that, since the late 1980s, piping

plover populations have increased steadily along the Atlantic Coast from 790 adults in

1986 to 1,349 adults in 1995 (USFWS 1996) and 2,581 adults in 1996 (USFWS 1999b).

Management and Protection

Habitat alterations such as marina construction, erosion control measures, and residential

development affect the dynamic nature of the beach ecosystem by altering sediment

patterns and hydrology, and inhibiting dune formation. Those actions may degrade or

destroy habitat for a variety of marine plants and animals (USFWS 1996, 1997; Cuthbert

et al. 1998). Off-road vehicles and high levels of foot traffic may erode sand dunes and

result in direct mortality by trampling (Bowles et al. 1990; USFWS 1997). The piping

plover is currently protected by Federal and state laws, which are enforced by the

USFWS and the LDWF, respectively. Critical habitat is also protected under

management programs on Federal lands (i.e., NWRs).

4.2.2 Brown Pelican

Status

The brown pelican was listed as endangered when project endangered species

coordination with USFWS began in early 2009. However, due to successful recovery

efforts, the brown pelican was removed from the Federal list of endangered and

threatened wildlife effective December 17, 2009 (Federal Register, Volume 74, Number

220) and will not be addressed further in this document.

4.3 MAMMALS

4.3.1 West Indian Manatee

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Status

The West Indian manatee was listed as endangered throughout its range for both the

Florida and Antillean subspecies in 1967, and received Federal protection with the

passage of the ESA in 1973. Critical habitat was designated in 1976, 1994, 1998, 2002,

and 2003 for the Florida subspecies.

Species and Habitat Description

The West Indian manatee is a large gray or brown aquatic mammal. Adults average

approximately 10 feet (3 m) in length and weigh up to 2,200 pounds (999 kg). They have

no hind limbs, and their forelimbs are modified as flippers. Manatee tails are flattened

horizontally and rounded. Their body is covered with sparse hairs and their muzzles with

stiff whiskers (USFWS 2001c). The nostrils, located on the upper snout, open and close

by means of muscular valves as the animal surfaces and dives (Husar 1977; Hartman

1979). Manatees will consume any aquatic vegetation (i.e., submerged, floating, and

emergent) available to them and sometimes even shoreline vegetation. Although

primarily herbivorous, they will occasionally feed on fish. Manatees may spend about

five hours a day feeding, and may consume four to nine percent of their body weight per

day.

Observations of mating herds indicate that females mate with a number of males during

their 2 to 4 week estrus period, and then they go through a pregnancy estimated to last 12

to 14 months (OShea et al. 1992). Births occur during all months of the year with a

slight drop during winter months. Manatee cows usually bear a single calf, but 1.5

percent of births are twins. Calves reach sexual maturity at three to six years of age.

Mature females may give birth every two to five years (USFWS 2001c).

Manatees inhabit both salt and freshwater of sufficient depth (5 feet [1.5 m] to usually

less than 20 feet [6.1 m]) throughout their range. Shallow grassbeds with ready access to

deep channels are preferred feeding areas in coastal and riverine habitats (USFWS

2001c). They may also be encountered in canals, rivers, estuarine habitats, saltwater

bays, and have been observed as much as 3.7 miles (6.0 km) off the Florida Gulf Coast.

Between October and April, Florida manatees concentrate in areas of warmer water.

Severe cold fronts have been known to kill manatees when the animals did not have

access to warm water refuges. During warmer months they appear to choose areas based

on an adequate food supply, water depth, and proximity to fresh water. Manatees may

not need fresh water, but they are frequently observed drinking water from hoses, sewage

outfalls, and culverts.

Range and Population Dynamics

During winter months, the United States manatee population confines itself to the

coastal waters of the southern half of peninsular Florida and to springs and warm water

outfalls as far north as southeast Georgia. Power plant and paper mill outfalls create most

of the artificial warm water refuges utilized by manatees.

During summer months, they migrate as far north as coastal Virginia on the east coast

and the Louisiana coast in the Gulf of Mexico. During summer months, manatees

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disperse from winter aggregation areas, and are commonly found almost anywhere in

Florida where water depths and access channels are greater than 3.3 to 6.6 feet (1.0 to 2.0

m) (OShea 1988). In the warmer months, manatees usually occur alone or in pairs,

although interacting groups of five to ten animals are not unusual (USFWS 2001c).

In the early 1980s, scientists tried to develop procedures for estimating the overall

manatee population in the southeastern United States (USFWS 2001c). The best estimate

throughout the State of Florida was 1,200 manatees (Reynolds and Wilcox 1987). In the

early 1990s, the State of Florida initiated a statewide aerial survey in potential winter

habitats during periods of severe cold weather (Ackerman 1995), and the highest count of

3,276 manatees was recorded in January 2001.

Management and Protection

The most significant problem faced by manatees in Florida is death or injury from boat

strikes (USFWS 2001c). Minimum flows and levels for warm water refuges need to be

established to ensure their long-term availability for manatees. Their survival will

depend on maintaining the ecosystems and habitat sufficient to support a viable manatee

population (USFWS 2001c). The focus of recovery is on implementing, monitoring, and

addressing the effectiveness of conservation measures to reduce or remove threats that

will lead to a healthy and self-sustaining population (USFWS 2001c).

The West Indian manatee is also protected under the Marine Mammal Protection Act

(MMPA) of 1972. The MMPA establishes a national policy for the maintenance of

health and stability of marine ecosystems and for obtaining and maintaining optimum

sustainable populations of marine mammals. It includes a moratorium on the taking of

marine mammals. The recovery planning under the ESA includes conservation planning

under the MMPA (USFWS 2001c).

4.4 REPTILES

4.4.1 Green Sea Turtle (Chelonia mydas)

Status

The green sea turtle was listed as endangered/threatened on July 28, 1978. The breeding

populations off Florida and the Pacific coast of Mexico are listed as endangered while all

others are threatened (USFWS 1991; National Marine Fisheries Service [NMFS]

www.nmfs.noaa.gov/). This species' current status in Louisiana is unknown (USFWS

1990b).

Species and Habitat Description

Although green sea turtles are found worldwide in oceans and gulfs with water

temperatures greater than 68°F (20°C), their distribution can be correlated to grassbed

distribution, location of nesting beaches, and associated ocean currents (Hirth 1971).

Long migrations are often made between feeding and nesting grounds (Carr and Hirth

1962). Within Louisiana waters, these turtles probably occur all along the coast and may

nest on the Chandeleur Islands (Dundee and Rossman 1989). Population decline has

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been attributed to heavy fishing pressure and human nest predation (Dundee and

Rossman 1989). Historically, green sea turtles were fished off the Louisiana coast (Rebel

1974); exploitation and incidental drowning in shrimp trawls has contributed to the

decline of this species and its eventual listing (King 1981). During their first year of life,

green sea turtles are primarily carnivorous, feeding mainly on invertebrates. As adults

they feed almost exclusively on seagrasses growing in shallow water flats (Fritts et al.

1983), but also feed on invertebrates and carrion (Dundee and Rossman 1989).

Green sea turtles feed in shallow water areas with abundant seagrasses or algae. The

turtles migrate from nesting areas to feeding grounds, which are sometimes several

thousand miles away. Most turtles migrate along the coasts, but some populations are

known to migrate across the ocean from nesting area to feeding grounds. The major

nesting beaches are always found in places where the seawater temperature is greater

than 77°F (25°C). As a species that migrates long distances, these turtles face special

problems associated with differing attitudes toward conservation in different countries.

Range and Population Dynamics

In the southeastern United States, green sea turtles are found around the U.S. Virgin

Islands, Puerto Rico, and the continental U.S. from Texas to Massachusetts. Important

feeding grounds in Florida include Indian River Lagoon, the Florida Keys, Florida Bay,

Homosassa, Crystal River and Cedar Key. The primary nesting sites in U.S. Atlantic

waters are along the east coast of Florida, with additional sites in the U.S. Virgin Islands

and Puerto Rico.

Green sea turtles are also found throughout the North Pacific, ranging as far north as

Eliza Harbor, Admiralty Island, Alaska, and Ucluelet, British Columbia. In the eastern

North Pacific, green sea turtles have been sighted from Baja California to southern

Alaska. In the central Pacific, green sea turtles can be found at most tropical islands. In

U.S. Hawaiian waters, green sea turtles are found around most of the islands in the

Hawaiian Archipelago. The primary nesting site is at French Frigate Shoals

(http://www.nmfs.noaa.gov/prot_res/species/turtles/green.html). Females deposit up to

seven clutches, and the number of nests has been estimated to be between 350 to 2,300

nests annually. Green sea turtles nest at two-, three-, or four-year intervals. This nesting

activity indicates a population of less than 1,000 females in the breeding population of

Florida and Mexico.

Management and Protection

Recovery plan objectives consider the delisting of green sea turtles if, over a period of 25

years, the following conditions are met: 1) the level of nesting in Florida has increased to

an average of 5,000 nests per year for at least 6 years (nesting data must be based on

standardized surveys), 2) at least 25 percent (41 mi2/105 km2) of all available nesting

beaches (162 mi2/420 km2) is in public ownership and encompasses at least 50 percent of

the nesting activity, and 3) a reduction in age class mortality is reflected in higher counts

of individuals on foraging grounds. The 1995 Biological Assessment lists degradation of

foraging grounds as one of the impediments to population recovery. There is evidence

that supports foraging site as well as nesting site fidelity by green sea turtles (Renaud

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1995). The recovery plans include prevention of marine pollution of green sea turtle

habitat and protection of the nesting sites.

4.4.2 Hawksbill Sea Turtle (Eretmochelys imbricata)

Status

The hawksbill was listed as an endangered species in June 1970 (USFWS 1991) and its

current status in Louisiana is unknown (USFWS 1990).

Species and Habitat Description

Only one record of a hawksbill in Louisiana has been reported (Fuller and Tappen 1986).

This species is an omnivore, feeding primarily on invertebrates and marine vegetation

(Dundee and Rossman 1989). Hawksbill turtles are observed regularly in Florida and

Texas. Florida is considered foraging habitat for those turtles, and Texas may be

foraging habitat for hatchlings and juveniles (77 observations of small turtles were

reported between 1972 and 1984) from the nesting sites in Mexico (NMFS and USFWS

1993).

Range and Population Dynamics

The hawksbill occurs in tropical and subtropical seas of the Atlantic, Pacific and Indian

Oceans. The species is widely distributed in the Caribbean Sea and western Atlantic

Ocean, with representatives of at least some life history stages regularly occurring in

southern Florida and the northern Gulf of Mexico (especially Texas); in the Greater and

Lesser Antilles; and along the Central American mainland south to Brazil. Within the

United States, hawksbills are most common in Puerto Rico and its associated islands, and

in the U.S. Virgin Islands. In the continental U.S., the species is recorded from all the

Gulf of Mexico states and from along the eastern seaboard as far north as Massachusetts,

but sightings north of Florida are rare.

Hawksbills are observed in Florida with some regularity on the reefs off Palm Beach

County and in the Florida Keys. Texas is the only other state where hawksbills are

sighted with any regularity. Most sightings involve post hatchlings and juveniles, which

are believed to originate from nesting beaches in Mexico. Nesting within the

southeastern United States occurs principally in Puerto Rico and the U.S. Virgin Islands.

Within the continental United States, nesting is restricted to the southeast coast of Florida

and the Florida Keys.

Hawksbill turtles nest at low densities in aggregations of one to one hundred adults; in

contrast, other sea turtles have concentrated nesting sites and aggregations of thousands

of adults. The Yucatan Peninsula of Mexico is the most concentrated nesting site, where

approximately 178 to 222 adult females nest each year (NMFS and USFWS 1993). Most

of the countries in the Caribbean report less than 100 females nesting annually; less than

two nests annually have been observed in Florida (NMFS and USFWS 1993) and Texas

(htpp://www.noaa.gov).

Management and Protection

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Recovery criteria are directed at nesting beaches with U.S. jurisdiction in the Caribbean

Sea, including Mona Island, Puerto Rico, and the Virgin Islands. The hawksbill turtle

can be delisted if the adult female population has an increasing trend over 25 years, as

evidenced by increases in annual number of nests at five index beaches, including Mona

Island. Numbers of turtles of all classes must show an increasing trend on at least five

key foraging areas within Puerto Rico, the U.S. Virgin Islands, and Florida to meet

recovery criteria. Actions needed to achieve recovery include long-term protection of

foraging habitat and nesting beaches, and reduction of illegal exploitation (NMFS and

USFWS 1993).

4.4.3 Kemps Ridley Sea Turtle (Lepidochelys kempii)

Status

On December 2, 1970 the Kemp's Ridley sea turtle was designated as endangered across

its entire range (USFWS 1991) and has continued to decline in Louisiana (USFWS

1990).

Species and Habitat Description

This small sea turtle is believed to be the most frequently encountered (Dundee and

Rossman 1989), if not the most abundant sea turtle, off the Louisiana coast (Viosca

1961). Predation on eggs by humans, other mammals, birds, and crabs, in addition to the

capture of diurnal nesting females has contributed to the decline of the Kemps Ridley.

Recent causes of mortality are fishing activities and accidental capture in shrimp trawls

(Fuller 1978; Pritchard and Marquez 1973). These sea turtles are commonly captured by

shrimpers off the Texas coast, as well as in heavily trawled areas off the coasts and in the

bays of Louisiana and Alabama (Dundee and Rossman 1989; Carr 1980; Pritchard and

Marquez 1973). Inshore areas of the Gulf of Mexico appear to be important habitat for

Kemps Ridleys, as they tend to concentrate around the mouths of major rivers (Frazier

1980). Members of this genus are characteristically found in waters of low salinity and

high turbidity and organic content, where shrimp are abundant (Hughes 1972, as cited in

Frazier 1980; Zwinenberg 1977). Kemps Ridleys have been collected in Louisiana from

Lake Borgne, Barataria and Terrebonne Bays, and near Calcasieu Pass (Dundee and

Rossman 1989). Occurrence of these sea turtles in bays and estuaries along the Louisiana

coast would not be unexpected, as many of their primary food items occur there.

Stomach analyses of specimens collected in shrimp trawls off Louisiana revealed crabs,

gastropods, and clams (Dobie et al. 1961). Although Kemps Ridleys are considered

primarily carnivorous benthic feeders (Ernst and Barbour 1972), jellyfish as well as bycatch from shrimp trawlers have been reported as part of their diet (Landry 1986).

Trends in Kemps Ridley sea turtle populations in the Gulf of Mexico are identified

through monitoring of their most accessible life stages on the nesting beaches, where

hatchling production and the status of adult females can be directly measured. Most

Kemp's Ridley nesting occurs on a single beach at Rancho Nuevo, Mexico, about 30

kilometers south of the Rio Grande, with sporadic nesting along the Texas coast.

Protection and monitoring by Mexico and the United States has occurred on that nesting

beach since 1978. Nest production plummeted to only 742 nests in 1985, but has been

steadily increasing since that time. Over 1,500 nests were observed during the 1994

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nesting season. The latest data available show that the number of nests increased during

1994 through 2000; in 2000, 5,751 nests were observed. The possibility of Kemps

Ridley nesting on the Louisiana coast has been suggested (Viosca 1961), but no

documentation exists.

Range and Population Dynamics

The known range of this species includes the Gulf of Mexico and the Atlantic Ocean.

The current range for Kemps Ridley in the United States includes marine habitat of the

following coastal states: Georgia, Florida, Alabama, Mississippi, Louisiana, and Texas.

Management and Protection

The Recovery Plan for the Kemp's Ridley sea turtle (NMFS and USFWS 1992) identified

a recovery criterion of 10,000 nesting females in one season as a prerequisite for

downlisting to threatened status. Considering that 58 percent of all adult females appear

to nest in any given year, and each female lays an estimated 2.7 nests, the 5,751 nests

documented in the year 2000 represent approximately 3,700 adult female Kemp's Ridleys

in the entire population; that is about one third of the amount included in the downlisting

criteria identified in the Recovery Plan. Continued protection of all life stages of the

Kemp's Ridley is necessary to increase recruitment to the reproducing population and

insure recovery of the species.

4.4.4 Leatherback Sea Turtle (Dermochelys coriacea)

Status

The leatherback sea turtle was listed as an endangered species throughout its range in

June 1970 (USFWS 199l).

Species and Habitat Description

The leatherback is the largest living turtle, and is so distinctive as to be placed in a

separate taxonomic family, Dermochelyidae. The carapace is distinguished by a rubberlike texture, about 1.5 in (4 cm) thick, and made primarily of tough, oil-saturated

connective tissue. No sharp angle is formed between the carapace and the plastron,

resulting in the animal being somewhat barrel-shaped. The average curved carapace

length for adult turtles is 5 ft (155 cm) and weight ranges from 440 to 1,543 lbs (200 to

700 kg). Hatchlings are dorsally mostly black and are covered with tiny scales; the

flippers are margined in white, and rows of white scales appear as stripes along the length

of the back. Hatchlings average 2.4 in (61.3 mm) long and 0.1 lbs (45.8 g) in weight. In

the adult, the skin is black and scaleless. The undersurface is mottled pinkish-white and

black. The front flippers are proportionally longer than in any other sea turtle, and may

span 8.9 ft (270 cm) in an adult. In both adults and hatchlings, the upper jaw bears two

tooth-like projections at the premaxillary-maxillary sutures. Age at sexual maturity is

unknown (http://www.nmfs.noaa.gov/prot_res/species/turtles/leatherback.html).

The leatherback sea turtle occurs mostly in continental shelf waters, but will occasionally

enter shallow waters and estuaries. Adults are highly migratory, and are believed to be

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the most pelagic of all sea turtles (NMFS and USFWS 1992). Habitat requirements for

juvenile and post-hatchling leatherbacks are unknown.

Leatherback turtles are omnivorous but feed primarily on jellyfish and other cnidarians,

and have been associated with large schools of cabbage head jellyfish (Stomolophus

meleagris). Fritts et al. (1983) reported that these turtles also ingest plastic, apparently

mistaking it for food.

Range and Population Dynamics

The leatherback is found throughout the tropical waters of the Atlantic, Pacific, and

Indian Oceans (Ernst and Barbour 1972), the Gulf of Mexico, and the Caribbean (Carr

1952). Critical habitat for the leatherback includes the waters adjacent to Sandy Point,

St. Croix, U.S. Virgin Islands, up to and inclusive of the waters from the hundred fathom

curve shoreward to the level of mean high tide with boundaries at 17°42'12" N and

64°50'00" W. This turtle exhibits seasonal fluctuations in distribution in response to the

Gulf Stream and other warm water features (Fritts et al. 1983; Hirth 1980; Pritchard

1971). During the summer, leatherbacks tend to be found along the east coast of the U.S.

from the Gulf of Maine south to mid-Florida.

Nesting occurs from February through July at sites located from Georgia to the U.S.

Virgin Islands. Nesting leatherbacks occur along beaches in Florida, Nicaragua, and

islands in the West Indies; however, no nesting has been reported in Louisiana (Gunter

1981; Dundee and Rossman 1989). In Louisiana, leatherbacks are believed to occur

offshore in deep waters; however, they have been sighted in Cameron Parish, Atchafalaya

Bay, Timbalier Bay, and Chandeleur Sound (Dundee and Rossman 1989).

Leatherbacks are seriously declining at all major nesting beaches throughout the Pacific.

The decline is dramatic along the Pacific coasts of Mexico, Costa Rica and Malaysia.

Nesting along the Pacific coast of Mexico declined at an annual rate of 22 percent over

the last twelve years, and the Malaysian population represents one percent of the levels

recorded in the 1950s. The collapse of those nesting populations was precipitated by a

tremendous over-harvest of eggs, direct harvest of adults, and incidental mortality from

fishing. In the Atlantic and Caribbean, the largest nesting assemblages are found in the

U.S. Virgin Islands, Puerto Rico, and Florida. Nesting data for these locations have been

collected since the early 1980s and indicate that the annual number of nests is likely

stable; however, information regarding the status of the entire leatherback population in

the Atlantic is lacking. Nesting activity has also declined in French Guiana due to

erosion of nesting beaches. The population appears to have shifted to Surinam, where

annual numbers of nests rose from less than 100 in 1967 to 5,565 in 1977 and 9,816 in

1987. Current estimates are that 20,000 to 30,000 female leatherbacks exist worldwide.

Management and Protection

Habitat destruction, incidental catch in commercial fisheries, and the harvest of eggs and

flesh are the greatest threats to the survival of the leatherback. Recovery plans are

directed at all leatherbacks in the U.S. portion of Caribbean, Atlantic, and Gulf of Mexico

waters, whether they are nesting within this area or elsewhere. Stranding data for the

United States shores indicate that stranded turtles are adult or near adult size, suggesting

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that leatherback turtles utilize the United States coastal waters for foraging as well as

nesting (NMFS and USFWS 1992). Leatherbacks begin nesting in February or March;

other sea turtles begin nesting in May. Leatherback strandings are highest (84 percent)

from October to April. Beach patrols are in place in May in most areas; however, few

strandings (16 percent) occur from May to September. Aerial surveys indicate the

presence of leatherback turtles in the southeastern U.S. in the winter months (NMFS and

USFWS 1992). The recovery plan for the leatherback sea turtle concludes that nesting

trends in the United States appear stable, but that the population faces significant threats

from incidental take as a result of commercial fishing and marine pollution.

4.4.5 Loggerhead Sea Turtle (Caretta caretta)

Status

The loggerhead sea turtle was listed as a threatened species in July 1978 (USFWS 1991)

and has continued to decline in Louisiana (USFWS 1990).

Species and Habitat Description

Loggerheads are capable of living in a variety of environments, such as in brackish

waters of coastal lagoons and river mouths. During the winter, they may remain

dormant, buried in the mud at the bottom of sounds, bays, and estuaries. The major

nesting beaches are located in the southeastern United States, primarily along the Atlantic

coast of Florida, North Carolina, South Carolina, and Georgia. Only minor and solitary

nesting has been recorded along the coasts of the Gulf of Mexico.

The largest of the hard-shell sea turtles, the loggerhead is distributed worldwide in

temperate and tropical bays and open oceans. Loggerheads probably range all along the

Louisiana coast; however, Dundee and Rossman (1989) reported specimens only from

Chandeleur Sound, Barataria Bay, and Cameron Parish. The population decline of

loggerheads can be attributed to egg and nestling predation by mammals and birds

(Dundee and Rossman 1989).

Nesting on the Gulf Coast occurs between the months of April and August, with 90

percent of the nesting effort occurring on the south-central Gulf Coast of Florida

(Hildebrand 1981). Although loggerheads have been documented as nesting on the

Chandeleurs in 1962 and Grand Isle in the 1930s, it is doubtful whether this species

currently successfully nests on the Louisiana coast (Hildebrand 1981; Dundee and

Rossman 1989). The loggerhead's diet includes marine invertebrates such as mollusks,

shrimp, crabs, sponges, jellyfish, squid, sea urchins, and basket stars (Caldwell et al.

1955; Hendrickson 1980; Nelson 1986). Landry (1986) suggested that these turtles may

also feed on discarded by-catch from shrimp trawling. Adult loggerheads feed in waters

less than 164 ft (50 m) deep, while the primary foraging areas for juveniles appears to be

in estuaries and bays (Nelson 1986; Rabalais and Rabalais 1980).

Nesting in the U.S. accounts for about one third of the Federally listed threatened

loggerhead worldwide population. Ninety-one percent of nesting occurs in Florida,

particularly within the Archie Carr NWR; the remaining U.S. nesting includes 6.5 percent

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in South Carolina, 1.5 percent in Georgia, and 1 percent in North Carolina. Nests are

constructed from May through September in the United States. According to Gosselink,

Coleman, and Stewart (http://biology.usgs.gov/s+t/SNT/noframe/cg138.htm), the only

loggerhead turtle nesting sites observed in Louisiana were on the Chandeleur Islands.

Because of storm processes, the Chandeleur Islands may no longer contain high beach

and dune surfaces, i.e., beach structure suitable for nesting. Recent surveys by USFWS

Refuge personnel have found no loggerhead nests in the area (James Harris, Southeast

Louisiana Refuges, personal communication).

Range and Population Dynamics

Loggerheads are circumglobal, inhabiting continental shelves, bays, estuaries, and

lagoons in temperate, subtropical, and tropical waters. In the Atlantic, the loggerhead

turtle's range extends from Newfoundland to as far south as Argentina. During the

summer, nesting occurs in the lower latitudes. The primary Atlantic nesting sites are

along the east coast of Florida, with additional sites in Georgia, and the Carolinas; some

nesting also occurs on the Gulf Coast of Florida. In the eastern Pacific, loggerheads are

reported as far north as Alaska, and as far south as Chile. Occasional sightings are also

reported from the coast of Washington, but most records are of juveniles off the coast of

California. Southern Japan is the only known breeding area in the North Pacific (NMFS,

http://www.nmfs.noaa.gov/prot_res/species/turtles/loggerhead.html).

Management and Protection

The Recovery Plan is currently being revised, but its recovery criteria for delisting

loggerhead sea turtles in the U.S. population include: 1) return to pre-listing nesting

levels for North Carolina, South Carolina, and Georgia, and 2) demonstration of an

increase in the adult female population of Florida (NMFS and USFWS 1993). Nesting

trends are stable in Florida, but appear to be declining in Georgia and South Carolina;

current trends in North Carolina have not been identified. Recent aerial survey data

indicate a current population of 14,150 adult females. Female turtles deposit a mean of

4.1 nests per year, which would be approximately 58,000 nests in the southeastern U.S.

That figure is supported by aerial and ground surveys that estimated between 50,000 and

70,000 nests annually in the southeastern U.S. Increasing the hatch success will

necessitate improvement of nesting habitat and minimizing mortality from commercial

fisheries.

5.0 POTENTIAL EFFECTS OF THE PROPOSED ACTION

The potential exists that any of the endangered or threatened species listed may be

present during proposed construction activities. However, while individuals may be

affected, whole populations are not likely to be adversely affected by implementation of

the proposed action.

5.1 FISH

5.1.1 Gulf Sturgeon

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The Gulf Sturgeon in the Gulf of Mexico is primarily found between Tampa Bay Florida

and the Mississippi River (Wooley 1985).Very few records exist for the Gulf sturgeon

occurring west of the Mississippi River (Wooley 1985; Todd Slack, ERDC, personal

communication 2010). There is no critical habitat located in the project area. The project

is not likely to have an adverse effect on the Gulf Sturgeon due to its low probability of

occurrence and lack of suitable habitat in the project area.

5.1.2 Pallid Sturgeon

While there are records of the pallid sturgeon occurring in the Atchafalaya River, there

are none for the project area itself (Schramm 2008; Paul Hartfield, USFWS, personal

communication 2010; Jack Kilgore, ERDC, personal communication 2010). The pallid

sturgeon is a river species that rarely travels into the adjacent marshes where construction

of project features would take place. Accordingly, the proposed activities are not likely

to adversely affect the pallid sturgeon.

5.2 BIRDS

5.2.1 Piping Plover

It is possible that piping plovers may be found utilizing exposed sand, mud, or algal flats

in the southern portions of the proposed project boundaries. However, piping plovers are

more likely to be foraging and roosting on barrier island and barrier headland habitats

located farther south of the project boundaries. The proposed project area would be

located well north of any designated critical habitat units for the piping plover.

Accordingly, the proposed activities are not likely to adversely affect the piping plover.

(Ronald Paille, USFWS, personal communication 2010).

5.3 MAMMALS

5.3.1 West Indian Manatee

Sightings of the West Indian manatee in Louisiana have occurred in the Amite, Blind,

Tchefuncte, Tickfaw, and Atchafalaya Rivers, MRGO, and in canals within the adjacent

coastal marshes of Louisiana. However, there is no known population thriving in the

State. Should any manatees be encountered during the proposed activities, an on-board

observer would notify the proper personnel, and harmful activities (e.g., dredging) would

be temporarily suspended until the animal(s) moves out of the area of operations. Any

disturbance to the manatee would only be temporary during construction activities, and

would result in temporary displacement. The manatees would likely move and relocate

to other nearby areas for foraging or resting purposes. Because the West Indian manatee

may occur in the project vicinity, the Contractor shall instruct all personnel associated

with the project of the potential presence of manatees in the area, and the need to avoid

collisions with these animals. All construction personnel shall be advised that there are

civil and criminal penalties for harming, harassing, or killing manatees, which are

protected under the Marine Mammal Protection Act of 1972 and the Endangered Species

Act of 1973. The Contractor shall be held responsible for any manatee harmed, harassed,

or killed as a result of construction activities not conducted in accordance with these

specifications.

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a. Special Operating Conditions If Manatees Are Present in the Project Area

(1) If a manatee(s) is sighted within 100 yards (91 m) of the project area, all appropriate

precautions shall be implemented by the Contractor to ensure protection of the manatee.

These precautions shall include the operation of all moving equipment no closer than 50

ft (15.2 m) from a manatee. If a manatee is closer than 50 ft (15.2 m) to moving

equipment or the project area, the equipment will be shut down and all construction

activities will cease to ensure protection of the manatee. Construction activities will not

resume until the manatee has departed and the 50-foot (15.2 m) buffer has been reestablished.

(2) If a manatee(s) is sighted in the project area, all vessels associated with the project

shall operate at "no wake/idle" speeds at all times while in waters where the draft of the

vessel provides less than a four-foot (1.2 m) clearance from the bottom, and vessels will

follow routes of deep water whenever possible. Boats used to transport personnel shall be

shallow-draft vessels, preferably of the light-displacement category, where navigational

safety permits.

(3) If siltation barriers are used, they will be made of material in which manatees cannot

become entangled, are properly secured, and are regularly monitored to avoid manatee

entrapment.

(4) Manatee Signs. Prior to commencement of construction, each vessel involved in

construction activities shall display at the vessel control station or in a prominent

location, visible to all employees operating the vessel, a temporary sign at least 8-1/2"

x11" (21.6 x 27.9 cm) reading, "CAUTION: MANATEE HABITAT/IDLE SPEED IS

REQUIRED IN CONSTRUCTION AREA." In the absence of a vessel, a temporary 3' x

4' (0.9 x 1.2 m) sign reading "CAUTION: MANATEE AREA" will be posted adjacent to

the issued construction permit. A second temporary sign measuring 8-1/2" x 11" (21.6 x

27.9 cm) reading "CAUTION: MANATEE HABITAT. EQUIPMENT MUST BE

SHUTDOWN IMMEDIATELY IF A MANATEE COMES WITHIN 50 FEET OF

OPERATION" will be posted at the dredge operator control station and at a location

prominently adjacent to the issued construction permit. The Contractor shall remove the

signs upon completion of construction.

b. Manatee Sighting Reports

Any sightings of manatees, or collisions with a manatee, will be reported immediately to

the Corps of Engineers. The point of contact within the CEMVN will be Edward Creef,

(504) 862- 2521, FAX (504) 862-2317.

5.4 REPTILES

5.4.1 Green Sea Turtle

Due to the lack of extensive seagrass beds in coastal Louisiana and the low incidence of

sightings and strandings, the proposed action is not likely to impact green sea turtle

populations.

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5.4.2 Hawksbill Sea Turtle

Due to its rarity along the Louisiana coast, the proposed action is not likely to impact

hawksbill sea turtle populations.

5.4.3 Kemps Ridley Sea Turtle

Kemps Ridley sea turtles concentrate near the mouths of rivers and in areas of low

salinity with high turbidity to forage for prey, including shrimp. Construction efforts

would not occur in this immediate area. The proposed wetland nourishment features

would provide more suitable inshore habitat (characterized by low salinity, and high

turbidity and organic content, where shrimp and blue crabs are abundant) utilized by this

species when foraging. Potential adverse project induced impacts are not likely to

adversely affect Kemps Ridley sea turtle populations.

5.4.4 Leatherback Sea Turtle

Leatherback sea turtles occur mostly in continental shelf waters more than 164 ft (50 m)

in depth. There are no known nesting records for this species reported for Louisiana.

Hence, the proposed action is not likely to adversely affect populations of leatherback sea

turtles.

5.4.5 Loggerhead Sea Turtle

The population decline of the loggerhead sea turtle can be attributed to egg and nestling

predation by mammals and birds. The only loggerhead sea turtle nesting sites historically

observed in Louisiana were on the Chandeleur Islands. The proposed action would have

no impacts on existing barrier habitats. Hence, the proposed action is not likely to

adversely affect loggerhead sea turtle populations.

6.0 SUMMARY OF DETERMINATIONS

6.1 FISH

The Gulf sturgeon has only been recorded west of the Mississippi River on a few

occasions (Todd Slack, ERDC, personal communication). The project is not likely to

have an adverse effect on the Gulf sturgeon due to its low probability of occurrence and

lack of suitable habitat in the project area.

Pallid sturgeon telemetry studies in the Atchafalaya River have not located the pallid

sturgeon in the vicinity of the project area. The fish is a species that is usually confined

to the river and would not be expected in the project area itself where any construction

activities would take place. The proposed action is not likely to adversely affect the

pallid sturgeon.

6.2 BIRDS

Potential impacts to piping plovers could be avoided by conducting proposed

construction activities outside the wintering season. If any proposed projects cannot be

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scheduled to take place outside the wintering season, piping plovers would be able to

avoid areas of temporary disturbance as long as there are feeding and/or roosting areas

available along the coast. Because any plovers remaining in the action area during

construction would be temporarily displaced to other suitable habitats in the vicinity, the

proposed action is not likely to adversely affect the piping plover. There is no piping

plover critical habitat in the project area and the project will not have any effect on piping

plover critical habitat (Ronald Paille, USFWS, personal communication 2010).

6.3 MAMMALS

The West Indian manatee is known to occur periodically in the coastal waters of

Louisiana. If a manatee were to stray into the project area, it may be attracted to noise

from proposed construction activities. Consequently, an onboard observer would be

present to alert the proper personnel, and harmful activities (e.g., dredging) would be

temporarily suspended until the animal could move to safety. Should a manatee be

sighted within any work areas, the USFWSs Lafayette, Louisiana, Field Office would be

contacted immediately. Therefore, the proposed action is not likely to adversely affect

the West Indian manatee.

6.4 REPTILES

The proposed action is not likely to adversely affect green, hawksbill, Kemps ridley,

leatherback, or loggerhead sea turtle populations. Most of those species are either rare

along the Louisiana Gulf coast or feed in nearby waters.

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7.0 LITERATURE CITED

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Wooley, C.M., and E.J. Crateau. 1985. Movement,

microhabitat, exploitation and management of

Gulf of Mexico sturgeon, Apalachicola River,

Florida. N. Amer. J. Fish. Manage. Pages 590-

605.

Zwinenberg, A.J. 1977. Kemp's Ridley, Lepidochelys

kempi (Gar-man 1880), undoubtedly the most

endangered marine turtle today (with notes on the

current status of Lepidochelys olivacea). Bull.

Maryland Herp.Soc. 13: 170-192.

606
APPENDIX B:

U.S. Fish and Wildlife Service Coordination

Letter and Report

607

Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock Appendix B  FWS Coordination Letter

Volume III

APPENDIX B:

U.S. Fish and Wildlife Service Coordination Letter and Report

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REVISED DRAFT

FISH AND WILDLIFE COORDINATION

ACT REPORT

on the

LOUISIANA COASTAL AREA  CONVEY

ATCHAFALAYA RIVER WATER TO NORTHERN

TERREBONNE MARSHES PROJECT

AND THE

MULTI-PUPOSE OPERATIONS OF THE HOUMA

NAVIGATION CANAL LOCK PROJECT

Submitted To

New Orleans District

U.S. Army Corps of Engineers

Prepared by

Ronald Paille

Senior Fish and Wildlife Biologist

U.S. Fish and Wildlife Service

Ecological Services

Lafayette, Louisiana

August 2010

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TABLE OF CONTENTS

INTRODUCTION ...........................................................................................................................1

DESCRIPTION OF THE STUDY AREA ......................................................................................2

FISH AND WILDLIFE RESOURCES ...........................................................................................3

Major Habitat Types ............................................................................................................3

Fishery Resources ................................................................................................................5

Wildlife Resources...............................................................................................................5

Threatened and Endangered Species ...................................................................................6

Species of Special Interest ...................................................................................................6

Refuges and Wildlife Management Areas ...........................................................................8

EVALUATION METHODOLOGY ...............................................................................................8

FUTURE WITHOUT PROJECT FISH AND WILDLIFE RESOURCES ...................................13

ALTERNATIVE PLAN DESCRIPTIONS ...................................................................................16

EVALUATION OF ALTERNATIVE PLANS .............................................................................27

FISH AND WILDLIFE CONSERVATION MEASURES...........................................................46

FUTURE SERVICE INVOLEMENT ..48

SERVICE POSITION AND RECOMMENDATIONS ................................................................49

LITERATURE CITED ..................................................................................................................52

APPENDIX A.A-1

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LIST OF FIGURES

Figure 1. Map delineating the project study area... 2

Figure 2. Map delineating study area subunits... 9

Figure 3. Actual and predicted wetland acreage in the G2,G3,G6 area. 9

Figure 4. Map delineating freshwater input benefit areas throughout the study area11

Figure 5. Subunits with no predicted wetland loss and with total FWOP wetland

loss by 206514

Figure 6. Location of the brackish-intermediate marsh interface in 1968 and 2007..14

Figure 7. Map illustrating the locations of Alternative 2 measures19

Figure 8. Map illustrating the locations of Alternative 3 measures20

Figure 9. Map illustrating the locations of Alternative 4 measures21

Figure 10. Map illustrating the locations of Alternative 5 measures..22

Figure 11. Map illustrating the locations of Alternative 6 measures..23

Figure 12. Map illustrating the locations of Alternative 7 measures..24

Figure 13. Map illustrating the locations of Alternative 8 measures..25

Figure 14. Locations along the GIWW, HNC, and Grand Bayou where predicted

discharges were obtained..29

Figure 15. Location of measure WD2.33

Figure 16. Lake Boudreaux Basin freshwater introduction sites and locations of

salinity outputs..34

Figure 17. Map depicting the location of the Davis Pond Diversion and the

5 ppt isohaline40

Figure 18. Map delineating alternative fisheries routes for Measure WW2 . 41

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Figure 19. Map delineating alternative fish access routes for Measure CP142

Figure 20. Lake Boudreaux Basin tidal pass discharges...43

Figure 21. Map delineating alternative fisheries access routes for Measure EP744

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LIST OF TABLES

Table 1. Projects incorporated into the FWOP wetland acreage predictions...10

Table 2. Descriptions of evaluated project alternatives.17

Table 3. List of measures within each alternative..18

Table 4. Descriptions of proposed measures..26-27

Table 5 Net benefits for project alternatives, in AAHUs (without fisheries impacts)...28

Table 6. Benefits for project alternatives, in net TY50 wetland acres...28

Table 7. Average monthly WS4 discharge into the Avoca Island Cutoff Channel29

Table 8a. GIWW flows in cfs for FWOP and Alt2 FWP...30

Table 8b. GIWW and Grand Bayou Canal flows in cfs for FWOP and Alt2 FWP...30

Table 9. FWOP and TSP discharge in un-improved channels connected to the GIWW..31

Table 10. FWOP and TSP discharge at locations on the HNC..32

Table 11. FWOP and TSP (Alt2) predicted average annual salinities in the subunits

above the Grand Pass plug.33

Table 12. Lake Boudreaux Basin predicted salinities, FWOP and TSP (Alt2).35

Table 13. FWOP and TSP (Alt2) predicted salinities north of the HNC lock..35

Table 14. FWOP and FWP freshwater inputs into the Grand Bayou system37

Table 15. FWOP and FWP monthly salinities for areas G2, G6, and G7.39

Table 16. FWOP and FWP average annual salinities for influence area G2,G3,G6.40

Table 17. Comparison of Alternative 3 benefits under low and medium SLR.41

Table 18. Summary of FWOP and FWP study area acreages by target year45

Table 19. Summary of construction impacts by habitat type46

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INTRODUCTION

The Feasibility Study Report and Supplemental Environmental Impact Statement (SEIS) for the

Louisiana Coastal Area  Convey Atchafalaya River Water to Northern Terrebonne Marshes

(ARTM) was prepared by the St. Louis District U.S. Army Corps of Engineers (USACE), on

behalf of the New Orleans District USACE, under the authority of Title VII of the Water

Resources Development Act (WRDA) of 2007. This SEIS tiers-off of an earlier Programmatic

Environmental Impact Statement (PEIS) provided in the November 2004 Louisiana Coastal Area

(LCA), Louisiana, Ecosystem Restoration Study, conducted by the New Orleans District

USACE. That PEIS, and the subsequent Chief of Engineers Report dated January 31, 2005,

recommend implementation of the ARTM project to reduce high coastal wetland loss rates in the

Terrebonne Basin of Louisiana.

The PEIS and Chief of Engineers Report also recommended implementation of the Louisiana

Coastal Area - Multi-Purpose Operations of the Houma Navigation Canal (HNC) Lock Project to

further reduce coastal wetland losses in the Terrebonne Basin marshes. As one of the primary

goals of this project is to improve distribution of Atchafalaya River freshwater in areas impacted

by the HNC, its effects are very much related to that of the ARTM project. Given their

interdependence, it was decided to include the feasibility study for the LCA Houma Navigation

Canal Lock Multi-Purpose Operations Project with that of the LCA ARTM Project to ensure

proper coordination between the two efforts.

The ARTM Project and the HNC Lock Multi-Purpose Operations Project were developed to

implement the Coast 2050 Regional Strategy# 4 to Enhance Atchafalaya River influence to

Terrebonne Marshes, excluding upper Penchant marshes (Louisiana Coastal Wetlands

Conservation and Restoration Task Force and the Wetlands Conservation and Restoration

Authority. 1998). The ARTM Project addresses that strategy by considering project features to

repair Gulf Intracoastal Waterway (GIWW) banks and enlarge GIWW constrictions to improve

water conveyance, as well as features to divert additional freshwater from the Atchafalaya River

through the Avoca Island Levee into Bayou Chene/GIWW system. Other evaluated features

include enlargement of Grand Bayou Canal and other waterways to improve freshwater inputs to

wetlands isolated from or receiving only a limited volume of Atchafalaya River freshwater.

Outfall management measures to increase retention times of introduced freshwater were also

evaluated.

This draft report contains a description of existing fish and wildlife resources in the project area,

discusses future with-project (FWP) and future without-project (FWOP) habitat conditions,

identifies fish and wildlife-related impacts, and provides recommendations to address major

errors and problems with the benefit assessment methods and results. Unfortunately, the

complexity of these projects, and the short study schedule, has precluded correction of several

major issues and the disclosure of final results. Consequently, we cannot complete our

evaluation of project alternatives on fish and wildlife resources and, therefore, cannot entirely

fulfill our reporting responsibilities under Section 2(b) of the Fish and Wildlife Coordination Act

(48 Stat. 401, as amended; 16 U.S.C. 661 et seq.) for the Tentatively Selected Plan alternative.

Therefore, additional Service involvement during subsequent detailed planning, engineering,

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design, and construction of specific project measures, will be required so that we can fulfill our

responsibilities under that Act.

When finalized, this report will be submitted in fulfillment of the requirements of the Fish and

Wildlife Coordination Act (FWCA; 48 Stat. 401, as amended; 16 U.S.C. 661 et seq.), and will

constitute the report of the Secretary of the Interior as required by Section 2(b) of that Act. This

revised draft FWCA Report incorporates comments provided by the Louisiana Department of

Wildlife and Fisheries (LDWF) and the National Marine Fisheries Service (NMFS) on the

Services May 2010 draft FWCA Report. Copies of the LDWF and NMFS comment letters may

be found in Appendix A of this report.

DESCRIPTION OF THE STUDY AREA

The study area extends from the Atchafalaya River eastward to Bayou Lafourche. It includes a

large portion of the Terrebonne Basin wetlands (Figure 1), located in the Louisiana central

coastal Deltaic Plain (within LCA Subprovince 3). Study area habitat types range from

freshwater bald cypress swamps and natural levee forests, to saline marshes bordering

Terrebonne and Timbalier Bays.

Figure 1. Map delineating the project study area.

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EXISTING FISH AND WILDLIFE RESOURCES

Brief descriptions of the study-areas principal fish and wildlife resources are provided in this

section. More detailed information is available in the Services Final Fish and Wildlife

Coordination Act Report on the Louisiana Coastal Area (LCA), Louisiana, Ecosystem

Restoration Study, and is incorporated herein by reference.

Major Habitat Types

Forested Wetlands - Forested wetlands in the study area consist primarily of bottomland

hardwood forests and cypress-tupelo swamps. Bottomland hardwood forests found in coastal

portions of the project area occur primarily on the natural levees of distributary channels and

older spoil banks. Dominant vegetation may include sugarberry, water oak, live oak, bitter

pecan, black willow, American elm, Drummond red maple, Chinese tallow-tree, boxelder, green

ash, baldcypress, and elderberry. Extensive cypress-tupelo swamps are located in the

northwestern portion of the study area (i.e., the northwestern Penchant Basin) and along the

flanks of larger distributary ridges as a transition zone between bottomland hardwoods and

lower-elevation marsh or scrub-shrub habitats. Cypress-tupelo swamps exist where there is little

or no salinity and (usually) minimal daily tidal action.

Scrub-Shrub - Scrub-shrub habitat is often found along the flanks of distributary ridges and

spoil banks. Typically, it is bordered by marsh at lower elevations and by developed areas,

cypress-tupelo swamp, or bottomland hardwoods at higher elevations. Typical scrub-shrub

vegetation includes elderberry, wax myrtle, buttonbush, black willow, Drummond red maple,

Chinese tallow-tree, and groundselbush.

Fresh Marsh - Fresh marshes occur at the upper ends of interdistributary basins and are often

characterized by floating or semi-floating organic soils. Most fresh marshes exhibit minimal

daily tidal action; however, fresh marshes in the Mississippi and Atchafalaya River deltas and

adjacent to Atchafalaya Bay are the exceptions. Vegetation may include maidencane,

bulltongue, cattail, California bulrush, pennywort, giant cutgrass, American cupscale,

spikerushes, bacopa, and alligatorweed. Associated open-water habitats may often support

extensive beds of floating-leaved and submerged aquatic vegetation including water hyacinth,

Salvinia, duckweeds, American lotus, white water lily, water lettuce, coontail, Eurasian milfoil,

hydrilla, pondweeds, naiads, fanwort, wild celery, water stargrass, elodea, and others.

Intermediate Marsh - Intermediate marshes are a transitional zone between fresh and brackish

marshes, and are often characterized by organic, semi-floating soils. Typically, intermediate

marshes experience low levels of daily tidal action. Salinities are negligible or low throughout

much of the year, with salinity peaks occurring during late summer and fall. Vegetation includes

saltmeadow cordgrass, deer pea, three-cornered grass, cattail, bulltongue, California bulrush,

seashore paspalum, wild millet, fall panicum, and bacopa. Ponds and lakes within the

intermediate marsh zone often support extensive submerged aquatic vegetation including

southern naiad, Eurasian milfoil, and wigeongrass.

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Brackish Marsh - Brackish marshes are characterized by low-to-moderate daily tidal energy and

by soils ranging from firm mineral soils to organic semi-floating soils. Freshwater conditions

may prevail for several months during early spring; however, low- to-moderate salinities occur

during much of the year, with peak salinities in the late summer to fall. Vegetation is usually

dominated by saltmeadow cordgrass, but also includes saltgrass, three-cornered grass, leafy

three-square, and deer pea. Shallow brackish marsh ponds occasionally support abundant beds

of wigeongrass.

Saline Marsh - Saline marshes occur along the southern fringe of the coastal wetlands. Those

marshes usually exhibit fairly firm mineral soils and experience moderate to high daily tidal

energy. Vegetation is dominated by saltmarsh cordgrass, but may also include saltgrass,

saltmeadow cordgrass, black needlerush, and leafy three-square. Submerged aquatic vegetation

is rare. Within the study area, intertidal mud flats are most common in saline marshes.

Ponds and Lakes - Natural marsh ponds and lakes interspersed throughout the coastal wetlands

are typically shallow, ranging in depth from 6 inches to more than 2 feet. The smaller ponds are

typically shallow and the larger lakes are deeper. In fresh and low-salinity areas, ponds and

lakes may support varying amounts of submerged and/or floating-leaved aquatic vegetation.

Brackish and, much less frequently, saline marsh ponds and lakes may support wigeongrass

beds.

Canals and Bayous - Canals and larger bayous typically range in depth from 4 or 5 feet, to more

than 15 feet. Strong tidal flows may occur at times through those waterways, especially where

they provide hydrologic connections to other large waterbodies. Such canals and bayous may

have mud or clay bottoms that range from soft to firm. Dead-end canals and small bayous are

typically shallow and their bottoms may be filled to varying degrees with semi-fluid organic

material. Erosion, due to wave action and boat wakes, together with shading from overhanging

woody vegetation, may retard the amount of intertidal marsh vegetation growing along the edges

of those waterways.

Navigation Channels - Navigation channels, such as the GIWW and HNC, have been dredged

within the study area. Boat wake erosion and water displacement surges from the passage of

large vessels have resulted in significant widening of those channel, in some cases to over 1,000

feet wide. Channels depths may range from 12 to 15 feet or more. The GIWW traverses the

study area from east to west. The HNC extends southward from the GIWW at Houma, into the

Gulf of Mexico. Because the GIWW is connected to the Atchafalaya River via Bayou Chene

and the Avoca Island Cutoff Channel, it serves as a seasonal distributary of the Atchafalaya

River during periods of moderate to high river discharge. During periods of low river discharge,

the HNC may allow saltwater intrusion to move northward into adjoining fresh and low-salinity

wetlands.

Developed Areas - Most developed areas are located on higher elevations of former distributary

channels and are typically well-drained. They include agricultural lands, and commercial and

residential developments.

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Fishery Resources

Wetlands throughout the study area abound with small resident fishes and shellfishes such as

least killifish, mosquitofish, sailfin molly, grass shrimp, and others. Those species are typically

found along marsh edges or among submerged aquatic vegetation, and provide forage for a

variety of fish and wildlife. Fresh and low-salinity marshes provide habitat for commercially

and recreationally important resident freshwater fishes such as largemouth bass, black crappie,

bluegill, readear sunfish, blue catfish, buffalo, freshwater drum, gar, and others.

The intermediate and more saline study area marshes provide important nursery habitat for many

estuarine-dependent commercially and recreationally important fishes and shellfishes such as

blue crab, white shrimp, brown shrimp, Gulf menhaden, red drum, black drum, spotted seatrout,

southern flounder, striped mullet, and others. Because of their important nursery habitat

function, commercial shrimp harvests have been positively correlated with the area of emergent

tidal marshes (Turner 1977).

Essential Fish Habitat

Essential Fish Habitat (EFH) is defined as those waters and substrates necessary to federally

managed fish species for spawning, breeding, feeding or growth to maturity. The proposed

project is located in an area identified as EFH for larval, postlarval, juvenile, subadult, and adult

life stages of brown shrimp (Farfantepenaeus aztecus), white shrimp (Litopenaeus setiferus), and

red drum (Sciaenops ocellatus). Categories of EFH that have been designated in the project area

include estuarine wetlands, water column, and mud, sand, and shell substrates. Detailed

information on federally managed fisheries and their EFH is provided in the 1998 generic

amendment of the Fishery Management Plans for the Gulf of Mexico prepared by the Gulf of

Mexico Fishery Management Council (GMFMC). The generic amendment was prepared as

required by the Magnuson-Stevens Act.

In addition to being designated as EFH for the above species and life stages, wetlands and water

bottoms in the project area provide nursery and foraging habitats supportive of a variety of

forage species that serve as prey for other fish species managed under the Magnuson-Stevens Act

by the GMFMC (e.g., mackerels, snappers, and groupers) and highly migratory species managed

by the NMFS (e.g., billfishes and sharks). Some prey species include striped mullet, white

mullet, Atlantic croaker, sand seatrout, silver perch, pinfish, spot, anchovies, silversides, and

killifish, as well as various shellfish species and benthic organisms. These wetlands also produce

nutrients and detritus, important components of the aquatic food web, which contribute to the

overall productivity of the various estuaries included in the study area.

Wildlife Resources

Study area coastal forested habitats provide important resting and feeding habitat for songbirds

migrating across the Gulf of Mexico, as well as habitat for numerous species of birds and raptors

such as bald eagle, osprey, barred owl, and others. Mammals utilizing coastal forested wetlands

may include white-tailed deer, swamp rabbit, and many other species. Amphibians and reptiles,

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such as American alligator, bullfrog, red-eared turtle, various snakes and other species also use

those habitats.

Study area marshes provide high quality habitat for migratory waterfowl such as gadwall, teal,

and others. Areas characterized by large open water areas are preferred by diving ducks such as

lesser scaup, redhead, ringnecked duck and others. Other migratory game birds using study area

marshes would include rails, American coot, moorhens, and snipe. Wading birds such as egrets,

herons, ibis, would also use these areas as would brown pelicans, white pelicans, shorebirds,

cormorants, and others.

Area marshes would also provide habitat for mammals such as nutria, muskrat, mink, river otter,

raccoon, and swamp rabbit. Reptiles and amphibians such as American alligator, water snakes,

turtles, bullfrog, and others, prefer the lower salinity marshes.

Threatened and Endangered Species

The Service provided a January 21, 2009, letter to the Corps identifying Federally listed

threatened and endangered species, their critical habitat, and migratory birds that may be found

in or near the study area. The species listed in that letter included the West Indian manatee

(Trichechus manatus), the brown pelican (Pelecanus occidentalis), the piping plover

(Charadrius melodus) and its critical habitat, the pallid sturgeon (Scaphirhynchus albus), Gulf

sturgeon (Acipenser oxyrhynchus desotoi), and 5 species of sea turtles. Since the date that letter

was provided, the brown pelican has been removed from the list of endangered species.

Otherwise, the information supplied in that letter has not changed and remains valid as of May

2010.

Although potential impacts to threatened and endangered species and their critical habitat

associated with the proposed Louisiana Coastal Area Ecosystem Restoration Study Near-Term

Plan have been addressed at the programmatic level, an additional Biological Assessment should

be prepared when individual projects that tier off that plan/PEIS may affect a Federally listed

threatened or endangered species and/or adversely affect designated critical habitats. In keeping

with the consultation requirements of the Endangered Species Act (ESA), informal and formal (if

needed) consultation must be completed regarding the ARTM and HNC Lock Multi-Purpose

Operations Projects before the Record of Decision for these LCA projects can be signed.

Species of Special Interest

Bald Eagle

The project-area forested wetlands provide nesting habitat for the bald eagle (Haliaeetus

leucocephalus), which was officially removed from the List of Endangered and Threatened

Species on August 8, 2007. There are numerous active bald eagle nests known to exist within

the northwestern portion of the study area. New nests may also be present that are not currently

listed in the database maintained by the Louisiana Department of Wildlife and Fisheries.

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Bald eagles nest in Louisiana from October through mid-May. Eagles typically nest in mature

trees (e.g., bald cypress, sycamore, willow, etc.) near fresh to intermediate marshes or open

water in the southeastern Parishes. Areas with high numbers of nests include the north shore of

Lake Pontchartrain and the Lake Salvador area. Major threats to this species include habitat

alteration, human disturbance, and environmental contaminants (i.e., organochlorine pesticides

and lead).

Breeding bald eagles occupy territories that they will typically defend against intrusion by

other eagles, and that they likely return to each year. A territory may include one or more

alternate nests that are built and maintained by the eagles, but which may not be used for nesting

in a given year. Potential nest trees within a nesting territory may, therefore, provide important

alternative bald eagle nest sites. Bald eagles are vulnerable to disturbance during courtship, nest

building, egg laying, incubation, and brooding. Disturbance during this critical period may lead

to nest abandonment, cracked and chilled eggs, and exposure of small young to the elements.

Human activity near a nest late in the nesting cycle may also cause flightless birds to jump from

the nest tree, thus reducing their chance of survival.

Although the bald eagle has been removed from the List of Endangered and Threatened Species,

it continues to be protected under the MBTA and the Bald and Golden Eagle Protection Act

(BGEPA). The Service developed the National Bald Eagle Management (NBEM) Guidelines to

provide landowners, land managers, and others with information and recommendations to

minimize potential project impacts to bald eagles, particularly where such impacts may

constitute disturbance, which is prohibited by the BGEPA. A copy of the NBEM Guidelines is

available at:

http://www.fws.gov/southeast/es/baldeagle/NationalBaldEagleManagementGuidelines.pdf.

Those guidelines recommend: (1) maintaining a specified distance between the activity and the

nest (buffer area); (2) maintaining natural areas (preferably forested) between the activity and

nest trees (landscape buffers); and (3) avoiding certain activities during the breeding season. Onsite personnel should be informed of the possible presence of nesting bald eagles within the

project boundary, and should identify, avoid, and immediately report any such nests to this

office. If a bald eagle nest is discovered within or adjacent to the proposed project area, then an

evaluation must be performed to determine whether the project is likely to disturb nesting bald

eagles. That evaluation may be conducted on-line at:

http://www.fws.gov/southeast/es/baldeagle. Following completion of the evaluation, that

website will provide a determination of whether additional consultation is necessary. A copy of

that determination should be provided to this office.

Brown Pelican

Although the brown pelican has been removed from the List of Endangered and Threatened

Species, brown pelicans and their nests continue to be protected under the Migratory Bird Treaty

Act. To minimize disturbance to nesting colonies of brown pelicans, all activity occurring within

2,000 feet of a rookery should be restricted to the non-nesting period (i.e., September 15 through

March 31).

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Colonial Nesting Birds

The proposed project would be located in an area where colonial nesting waterbirds may be

present. Colonies may be present that are not currently listed in the database maintained by the

Louisiana Department of Wildlife and Fisheries. That database is updated primarily by

monitoring the colony sites that were previously surveyed during the 1980s. Until a new,

comprehensive coast-wide survey is conducted to determine the location of newly-established

nesting colonies, we recommend that a qualified biologist inspect the proposed work site for the

presence of undocumented nesting colonies during the nesting season. To minimize disturbance

to colonial nesting birds, the following restriction on activity should be observed:

For colonies containing nesting wading birds (i.e., herons, egrets, night-herons, ibis, and

roseate spoonbills), anhingas, and/or cormorants, all activity occurring within 1,000 feet

of a rookery should be restricted to the non-nesting period (i.e., September 1 through

February 15, exact dates may vary within this window depending on species present).

In addition, we recommend that on-site contract personnel be informed of the need to identify

colonial nesting birds and their nests, and should avoid affecting them during the breeding

season.

Refuges and Wildlife Management Areas

The Mandalay National Wildlife Refuge is located on the GIWW west of Houma, Louisiana. No

proposed project features would be located on that refuge, and no significant indirect project

effects are expected to occur there. The state-owned Pointe-aux-Chenes Wildlife Management

Area is located within the Grand Bayou watershed and would be directly affected by the

proposed measures to increase freshwater introduction into that area. State owned and managed

oyster seed grounds in Lake Mechant, Caillou Lake (Sister Lake), Lake Chien, and other areas

may be affected by project-related freshwater introduction. Please contact the Louisiana

Department of Wildlife and Fisheries in Baton Rouge, Louisiana, (225/765-2360) for their

comments regarding potential project impacts to these areas.

EVALUATION METHODOLOGY

Given the compressed study schedule and the time necessary to conduct hydraulic modeling of

project measures and alternatives, the benefits methodology had to be conducted quickly.

Because the WVA and the SAND2 model are desktop models that can be run quickly, and were

already in the Corps model certification process, they were selected for use.

To evaluate benefits of individual project measures, the study area was subdivided into numerous

subunits or polygons representing wetlands of similar characteristics and wetland loss patterns

(Figure 2). The U.S. Geological Survey (USGS) provided wetland acreage data (1985-2008) for

each of the subunits. Future-without-project (FWOP) subunit wetland acreages were determined

via a linear trendline through those data (Figure 3). Where applicable, annual net acreage

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Figure 2. Map delineating study area subunits.

Figure 3. Actual and predicted wetland acreage in the G2,G3,G6 area.

10,000

12,000

14,000

16,000

18,000

20,000

22,000

24,000

26,000

28,000

30,000

1980199020002010202020302040205020602070

Wetland Acres

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benefits associated with pre-existing or soon to be constructed restoration projects (Table 1) were

added to the subunit FWOP acreages to obtain revised FWOP subunit acreages.

Table 1. Projects incorporated into the FWOP wetland acreage predictions.

Year

Constr.

Effected

Subunit(s) Project

2009 C9 CWPPRA West Lake Boudreaux Shoreline Protection Project and Marsh

Creation Project (TE-46)

2009 A7,L.Pagie CWPPRA North Lake Mechant Landbridge Restoration Project (TE-44)

2000 A6,A7,L.Pagie CWPPRA Brady Canal Hydrologic Restoration Project (TE-28)

2010 A6,A7,L.Pagie CWPPRA Penchant Basin Natural Resources Plan, Increment 1 (TE-34)

2010 A7 CWPPRA South Lake De Cade Freshwater Introduction Project (TE-39)

2010 A3 CWPPRA GIWW Bank Restoration of Critical Areas in Terrebonne Project

(TE-43)

Those FWOP wetland acreages were used in conjunction with the Wetland Value Assessment

(WVA) methodology to determine project-related impacts on fish and wildlife resources. The

Wetland Value Assessment (WVA) methodology, developed for the evaluation of proposed

CWPPRA projects under the Louisiana Coastal Wetlands Planning, Protection and Restoration

Act program, is similar to the Services Habitat Evaluation Procedures (HEP) in that habitat

quality and quantity are measured for baseline conditions and predicted for FWOP and future

with-project (FWP) conditions. However, instead of the species-based approach of HEP, each

WVA model utilizes an assemblage of variables considered important to the suitability of a given

habitat type for supporting a diversity of fish and wildlife species. As with HEP, these models

allow a numeric comparison of each future condition and provide a combined quantitative and

qualitative estimate of project-related impacts to fish and wildlife resources.

The WVA models operate under the assumption that optimal conditions for fish and wildlife

habitat within a given coastal wetland type can be characterized, and that existing or predicted

conditions can be compared to that optimum to provide an index of habitat quality. Habitat

quality is estimated and expressed through the use of a mathematical model developed

specifically for each habitat type. Each model consists of: 1) a list of variables that are

considered important in characterizing fish and wildlife habitat; 2) a Suitability Index graph for

each variable, which defines the assumed relationship between habitat quality (Suitability

Indices) and different variable values; and 3) a mathematical formula that combines the

Suitability Indices for each variable into a single value for wetland habitat quality, termed the

Habitat Suitability Index (HSI).

The product of an HSI and the acreage of available habitat for a given target year is known as the

Habitat Unit (HU). The HU is the basic unit for measuring project effects on fish and wildlife

habitat. Future HUs change according to changes in habitat quality and/or quantity. Results are

annualized over the project life to determine the Average Annual Habitat Units (AAHUs)

available for each habitat type. The AAHU outputs provide a measure of the suitability of each

habitat type for providing resting, foraging, breeding, and nursery habitat to a diverse assemblage

of fish and wildlife species. The FWP action alternatives were evaluated by comparing their net

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11

AAHUs (FWP AAHUs minus FWOP AAHUs). The 2009 version of the WVA

methodology/models were used to conduct the ARTM assessments (LCWCRTF 2009). In

addition to the baseline condition in 2015 (TY0), WVA target years of 1, 10, and 50 were chosen

as target tears (TYs).

A Service biologist familiar with the project area supplied WVA input values for variables 2-4,

(submerged aquatic vegetation coverage, marsh edge and interspersion, percent shallow open

water, respectively) and variable 6 (aquatic organism access), based on knowledge of the area,

experience with similar projects, and examination of Digital Ortho-quarter Quadrangle aerial

photographs (DOQQ). Inputs for variable 5 (salinity) were derived from hydraulic modeling

conducted specifically for this purpose. For portions of the study area affected by freshwater

inputs, variable 1 (percent emergent marsh), was determined through the use of the SAND2

model (ERDC-Boustany diversion benefits model) for each target year. A listing of variables

used in the assessment of project measures is provided in Appendix A. More detailed

information regarding these methods may be found in the ARTM Main report and Supplemental

EIS. Because there was not sufficient time to conduct detailed hydraulic modeling to determine

the extent of each specific freshwater introduction influence area, one or more of the study area

subunits were identified as the benefit area based on knowledge of area hydrology (Figure 4).

Figure 4. Map delineating freshwater input benefit areas throughout the study area.

Using the FWOP wetland acreage forecasts (discussed above) for a specific benefit area, the

SAND2 model predicts FWP wetland acreage for that area, based on benefits associated with

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12

increased discharge and the concentration of nitrogen and suspended sediment in that discharge.

Because portions of the study area currently receive some Atchafalaya River freshwater input,

the SAND2 model was run using the net increase or decrease in freshwater input. Although the

SAND2 model is capable of predicting wetland gains associated with deltaic land-building, the

study team felt that it would be inappropriate to generate land-building benefits given that deltaic

land-building is not currently occurring throughout most of the area, and because the modest

increases in Atchafalaya River water inputs would not be of sufficient magnitude to initiate

deltaic land-building. Consequently, suspended sediment inputs in the SAND2 model were set to

zero. Where project measures would decrease freshwater input, the SAND2 model was run in

reverse by entering the net flow decrease as a flow increase. The model-predicted wetland

acreage gain was then multiplied by -1.0 to convert the gain into a net wetland acreage loss.

Indirect effects of outfall management measures were captured in the hydraulic model-generated

net discharges used to predict wetland acreage via the SAND2 model and model-generated

salinities (used as variable 5 in the WVA marsh models). Benefits associated with marsh

creation measures located within the freshwater input influence areas were incorporated into the

benefits generated by the SAND2 model as the nutrient additions associated with freshwater

inputs were assumed to reduce both the loss rates of existing natural marshes and the created

marshes. Similarly, wetland impacts associated with channel enlargements were in most cases

also incorporated into SAND2 model results. If not, those impacts were quantified independent

of the SAND2 modeling. Some proposed marsh creation or outfall measures were located

outside of the previously determined freshwater influence area(s). Those measures were

considered independent of freshwater introduction measures and their benefits were quantified

using the WVA alone.

The 1985  2008 USGS wetland acreage data used in these assessments were assumed to

incorporate a low rate of sea-level rise (SLR). U.S. Army Corps of Engineers guidance now

requires that benefit assessments also be conducted under anticipated medium and high SLRs.

Wetland loss rates under low SLR were used as a basis for calculating wetland loss rates under

increased SLR scenarios. Water level rise data from the Grand Isle and Eugene Island gages was

used to determine that the baseline (year 2004) relative sea level rise rate (RSLR) equals 11.15

mm/yr. This gage-derived RSLR rate was then reduced by the average study area back-marsh

accretion value of 10.2 mm/yr to calculate a baseline accretion-adjusted RSLR rate of 0.95

mm/yr. By adding predicted eustatic SLR estimates provided by the Corps, future RSLR rates

were determined annually for the medium and high SLR scenarios. According to Corps

estimates, increased SLR rates begin to occur in 2005. Likewise, wetland loss rates would begin

to accelerate in 2005. To calculate future wetland loss rates under the medium and high SLR

scenarios, the baseline wetland loss rate, in acres lost per year, was multiplied by the year X

submergence rate ratio (i.e., accretion-adjusted RSLR year X/baseline accretion-adjusted RSLR

Rate from 2004). In this manner, future wetland loss rates under the medium and high SLR

scenarios were calculated for every year of the 50-year project life.

Because of accelerating SLR, the wetland loss rates increase every year under the medium and

high SLR scenarios. Given that the SAND2 model can incorporate only 3 different loss rates,

the 50-year project life was split evenly into 3 periods and an average loss rate was determined

for each period. All freshwater introduction wetland acreage benefits under the medium and

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13

high SLR scenarios used the average loss rates from those 3 periods. In addition to using those

increased wetland loss rates, the average water depth input to the SAND2 model was increased

to reflect increased water depths. Given that the medium SLR scenario would result in

approximately a 6-inch water level increase by TY25, the average water depth used in the

SAND2 model runs was increased by 0.5 feet.

With the accelerating SLR forecasted under medium and high scenarios, the submergence of

coastal marshes is assumed to reach a point at which feedback processes result in rapid marsh

collapse. Based on Nyman et al. 1993, the collapse threshold was assumed to occur when the

accretion-adjusted RSLR rate reached 10 mm/yr. Under the medium SLR scenario, this

threshold would not be reached within the 50-year project life, however, it would be reached in

year 2032 under the high SLR scenario. The study team agreed that once the collapse threshold

was reached, all marsh would be lost within 10 years. Given the limited amount of time

available to conduct the benefits analysis, the team agreed to assess TSP benefits under the

medium SLR scenario only, since the catastrophic wetland loss under the high SLR scenario

would provide little if any benefit prior to system collapse.

FUTURE WITHOUT-PROJECT FISH AND WILDLIFE RESOURCES

FWOP wetland acreages were predicted by extrapolation of loss rates observed from 1985 to

2008. Consequently, wetland degradation and loss is assumed to continue throughout much of

the study area, except for the northwestern portion of the study area, which is heavily influenced

by Atchafalaya River freshwater inputs and is relatively stabile. Central and eastern portions of

the study area, which are generally isolated from or receive little beneficial riverine input,

generally exhibit the greatest wetland loss rates (Figure 5). Some portions of the eastern study

area will lose all their marshes prior to the end of the project life.

Over the last 39 years, brackish marshes in western portions of the project area have experienced

a conversion to intermediate marshes (Figure 6). Based on current information, the intermediate

marsh-brackish marsh interface has moved southward into an area of high marsh loss, and just

north of Lost Lake and Lake Mechant. Given the rapid marsh loss in these areas, and the very

steep salinity gradient in the marshes north of Lake Mechant, it is unlikely that those brackish

marshes will continue transitioning to lower salinity habitat types. Conversely, the continued

subsidence of the Mauvious Bios ridge (which once served as a barrier to marine invasion of the

Penchant Basin fresh marshes), and the continuing degradation of buffering tidal marshes south

of the Mauvois Bois ridge, may not only halt the past freshening trend, but may also result in

increased degradation of southern Penchant Basin fresh marshes.

These observed habitat shifts are likely related to hydrology effects of man-made canals

constructed decades ago. The Avoca Island Cutoff Channel, Bayou Chene, and the GIWW

provide a direct connection between the northwestern study area (Penchant Basin) and the

Atchafalaya River. The USGS has determined that Bayou Chene and the GIWW become a

distributary of the lower Atchafalaya River (LAR) when Morgan City stages reach and/or exceed

+3.0 feet NAVD88. Under such conditions, GIWW flows just west of Houma respond very well

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14

Figure 5. Subunits with no predicted wetland loss and with total FWOP wetland loss by 2065.

Figure 6. Location of the brackish-intermediate marsh interface in 1968 and 2007.

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15

to stages of the Atchafalaya River at Morgan City (Swarzenski 2003). Additionally, the USGS

found that those GIWW eastward flows have increased considerably from the mid 1980s to the

late 1990s, due in part to the downstream emergence of the Atchafalaya Delta in the later 1970s

and the aggradation of the river bed. The USGS has also indicated that if those processes

continue, The percent of time when stage of the LAR is greater than 3 feet above NAVD88

could increase in the future with further aggradation of the river bed. The above-mentioned

GIWW freshwater flow increases, combined with the numerous waterways connecting the

GIWW with Penchant Basin marshes to the south, has resulted in the Penchant Basin being one

of two or three areas statewide where non-impounded freshmarsh habitats have not experienced

substantial conversion to more saline habitats.

The lack of northward shifting saline habitats is also apparent along the HNC, and is likely

related to the fact that the majority of eastward GIWW freshwater exits the GIWW via the HNC

(Swarzenski 2003). That this trend exists despite the opposing seasonal saltwater intrusion

events occurring on the HNC, illustrates the magnitude of the seasonal freshwater resource

available along the HNC, a resource that is apparently not available to eastern study area

marshes. Because the HNC so efficiently discharges water to the Gulf on falling tides, HNC

freshwater is distributed laterally into adjoining marshes primarily on the rising tide. Falgout

Canal and Bayou Grand Caillou are major conduits for carrying HNC freshwater laterally into

adjoining marshes.

Wetlands in the central and eastern portions of the study area have experienced a conversion of

fresher marsh types to more saline habitat types (Figure 6). The Lake Boudreaux Basin, located

east of the HNC and immediately south of Houma, is isolated from Atchafalaya River freshwater

inputs. During periods of high Atchafalaya River stages, incoming tides on the HNC may push

freshwater northeastward up Bayou Grand Caillou into the southwest portion of that basin.

However, that freshwater has a minimal beneficial effect given the large volumes of saltwater

which enter that basin through Robinson Canal and Boudreaux Canal.

Because of increased basin-wide salinities, the bald cypress swamps within the upper basin have

been virtually eliminated, as have been the upper basin freshmarsh habitat. Most of those former

freshwater habitats in the northern basin have converted to open water, however some of the

marshes closer to Lake Boudreaux have converted to degraded brackish marsh.

East of Houma, GIWW freshwater may flow southward into Bayou Terrebonne via Company

Canal. The majority of those minimal freshwater flows exit Bayou Terrebonne via Humble

Canal and flow into the Bayou Barre system. During periods of high Atchafalaya flows, a weak

salinity gradient may be observed in the Bayou Barre area. Because most of the marsh in this

area has been lost, those minimal freshwater inputs likely result in little if any benefit.

GIWW freshwater may also flow southward into the Grand Bayou system via Bayou LEau

Bleu. Those freshwater inputs range up to 500 cubic feet per second (cfs), according to U.S.

Fish and Wildlife Service measurements. Despite those beneficial freshwater inflows, much of

the Grand Bayou system has experienced substantial habitat shift toward more brackish and

degraded conditions, due in part to construction of the Cutoff Canal through the Bayou Pointe

aux Chene ridge. That canal has connected Bayou Jean LaCroix and Lake Chien to the south,

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16

with Grand Bayou, in roughly the middle of the Grand Bayou Basin. With the collapse of the

southern rim of Lake Chien and Lake Felicity in the 1950s, saline waters of Timbalier Bay were

then readily able to flow northward into the middle of the Grand Bayou system, which was

dominated by fresh and intermediate marshes in 1968. Wetland losses in the Grand Bayou basin

have been severe, especially in the organic soil marshes of the former fresh marsh zone. Low

salinity marshes still remain in the extreme northwest end of the Grand Bayou basin due in part

to a lack of canals and waterways capable of readily transmitting brackish water into this intact

area. Loss rates within these areas are lower than in most portions of the basin, but losses there

have begun to increase in more recent years.

Despite the high wetland loss rates and the corresponding need for freshwater inputs in the

central and eastern study areas, most of the GIWW freshwater flowing east past Houma remains

in the GIWW where it continues eastward into the Barataria Basin. The need for freshwater

there is less than in the Terrebonne Basin since the Davis Pond Freshwater Diversion Project is

operated to maintain the Barataria Basins salinity regime. Compared to eastward GIWW

freshwater flows at Houma, the eastward GIWW flows at Larose are much less consistent

(USGS 2003). However, USGS gage data1 reveal that annually, peak flows range up to 4,000 cfs

or more.

Continued degradation and loss of marshes in central and eastern portions of the study area will

have drastic adverse effects on fish and wildlife resources. Wildlife will be especially impacted

as the few remaining areas of low-salinity habitats continue to transition to more saline habitat

types that provide lesser quality habitat for many wildlife species. Impacts on estuarinedependent fishes and shellfishes will be less obvious initially as continued marsh degradation

will replace nursery habitat lost through mash degradation in other areas. Ultimately, however,

when area wetland acreage is further reduced and the remaining marshes are sufficiently

degraded, fisheries productivity may experience a steep decline.

Because of abundant freshwater resources, western study area marshes will likely not experience

the decline in habitat diversity that has for the most part already occurred in the central and

eastern portions of the study area. Future adverse impacts to wildlife will therefore not be as

severe in the western areas as it will be in the central and eastern study area. Because marsh loss

rates of brackish marshes are lower in the western portion of the study area, adverse impacts to

estuarine-dependent fisheries will also be less there than in the central and eastern study area.

ALTERNATIVE PLAN DESCRIPTIONS

Due to the many wetland restoration measures identified during the scoping process, and the

limited time available to conduct hydrologic modeling on individual or small groups of

measures, numerous measures were combined to create an array of alternatives that focused on

the major study-area restoration strategies (Table 2). Tables 3 and 4, respectively, provide a

__________________________________________ 1 http://waterdata.usgs.gov/la/nwis/uv/?site_no=07381235&PARAmeter_cd=00065,72020,63160,00060

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17

listing of measures within each alternative and a brief description of those measures. All

alternatives included the Multi-Purpose HNC Lock Operations (year-round closure of the HNC

Lock to improve distribution of HNC freshwater).

Table 2. Descriptions of evaluated project alternatives.

ARTM 7: Utilize modified operation of the Houma Navigation Canal Lock Complex to distribute freshwater and

ARTM 5 : Increase Atchafalaya River Inflows, Utilize Pump at Grand Bayou, and implement Flow Management

Measures to Maximize Restoration Efforts. Alternatives developed under this strategy will focus on

maximizing flow inputs from both the Atchafalaya Riv

ARTM 6 : Increase Atchafalaya River Inflows and Utilize Grand Bayou Dredging with no Flow Management

Measures. Alternatives developed under this strategy will focus on maximizing flow inputs from the

Atchafalaya River, removing GIWW constrictions, and imp

ARTM 8 : Utilize Flow Management Measures to Maximize Benefits of Existing Freshwater Flows in Central and

Eastern Sub-Areas. Alternatives developed under this strategy will focus on constructing flow management

features in the interior portions of the Ce

ARTM 1 : No Action. Alternatives developed under this strategy will include no measures from this

project. The future condition will include sea level rise, subsidence, and other projects that are under

construction or are likely to be constructed.

ARTM 2 : Utilize Flow Management Measures to Maximize Benefits of Existing Freshwater Flows. Alternatives

developed under this strategy will focus on eliminating GIWW constrictions and constructing flow

management features in the interior portions of the

ARTM 3 : Increase Atchafalaya River Inflows and Utilize Flow Management Measures to Maximize Restoration

Efforts. Alternatives developed under this strategy will focus on increasing supply from the Atchafalaya

River to introduce additional freshwater in a

ARTM 4 : Utilize Pump at Grand Bayou and Flow Management Measures to Maximize Restoration Efforts.

Alternatives developed under this strategy will focus on attempting to utilize existing GIWW flows from

the west and potentially drawing water from the east

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Table 3. List of measures within each alternative.

Alternative

Alt 1 - No Action

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

Alt 2 - Flow MgmtMeasures Only

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

Alt 3 - IncreasedAtchafalaya Inflows plusFlow Mgmt Measures

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

Alt 4 - Pump at GrandBayou plus Flow MgmtMeasures

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

Alt 5 - IncreasedAtchafalaya Inflows andPump at Grand Bayouplus Flow MgmtMeasures

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

Alt 6 - IncreasedAtchafalaya Inflows withno Flow MgmtMeasures

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

Alt 7 - Modified LockOperation only

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

Alt 8

WD2

WD3

WP1

WO1

WO2

WS4

WW2

CC1

CC2

CC3

CC4

CC5

CC6

CC7

CC8

CC9

CC10

CC11

CC12

CC13

CC14

CC15

CD1

CD2

CD3

CD4

CD6

CD7

CL1

CLV1

CLV2

CM2

CM3

CM4

CP1

CP2

CS1

CT1

CT2

CT3

CT6

CT7

CT8

West Central

EC2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

EC2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

EC2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

EC2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

EC2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

EC2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

EC

2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

EC2

EC3

EC5

EC6

EC7

ED2

ED3

ED5

ED6

ED7

EM1

EM3

EG1

EG2

EP7

EP8

ES2

EX1

EX2

East

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19

Figure 7. Map illustrating the locations of Alternative 2 measures.

650
20

Figure 8. Map illustrating the locations of Alternative 3 measures.

651
21

Figure 9. Map illustrating the locations of Alternative 4 measures.

652
22

Figure 10. Map illustrating the locations of Alternative 5 measures.

653
23

Figure 11. Map illustrating the locations of Alternative 6 measures.

654
24

Figure 12. Map illustrating the locations of Alternative 7 measures.

655
25

Figure 13. Map illustrating the locations of Alternative 8 measures.

656
26

Table 4. Descriptions of proposed measures.

Feature ID Feature Name Description Purpose Source

EC1 East Culvert #1 FLAP GATED CULVERT Prevent saltwater movement to west CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

EC2 East Culvert #2 BOX CULVERT Allow water movement from Grand Bayou to southwest CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

EC3 East Culvert #3 FLAP GATED BOX CULVERTS W/VARIABLE CREST OUTFALL

Allow fresh water movement from Grand Bayou to northwest; prevent saltwater

movement from Grand Bayou to northwest; allow control of water levels in

marshes to northwest CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

EC5 East Culvert #5 FLAP GATED BOX CULVERTS Allow water movement from GIWW to Grand Bayou under highway LCA

EC6 East Culvert #6 FLAP GATED BOX CULVERTS Allow water movement down St. Louis Canal under road LCA

EC7 East Culvert #7 FLAP GATED BOX CULVERTS Allow water movement down St. Louis Canal under road LCA

ED2 East Dredge Channel #2 43,000' OF CANAL DREDGING Allow water movement from GIWW to Grand Bayou basin LCA

ED3 East Dredge Channel #3 16,000' OF CANAL DREDGING Allow water movement from GIWW to Grand Bayou basin CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

ED4 East Dredge Channel #4 7000' OF CANAL DREDGING Allow water movement from GIWW to Grand Bayou basin CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

ED5 East Dredge Channel #5 1000' OF CANAL DREDGING Allow water movement from GIWW to Grand Bayou LCA

ED6 East Dredge Channel #6 17,000' OF CANAL DREDGING Allow water movement from Grand Bayou to eastern marshes CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

ED7 East Dredge Channel #7 13,000' OF CANAL DREDGING Allow water movement further down Grand Bayou CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

EM1 East Marsh Creation #1 13,000 LINEAR FEET OF MARSH CREATION Retain fresh water in marshes to north; prevent saltwater intrusion from south LCA

EM3 East Marsh Creation #3 37,000 LINEAR FEET OF MARSH CREATION Retain fresh water in marshes to north; prevent saltwater intrusion from south LCA

EG1 East Spoil Gap #1 GAP IN CANAL SPOIL BANK Allow movement of fresh water from canal to marshes to the south/southwest CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

EG2 East Spoil Gap #2 GAP IN CANAL SPOIL BANK Allow movement of fresh water from canal to marshes to the east CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

EP7 East Plug #7 CUTOFF CANAL PLUG Retain fresh water in marshes to north; prevent saltwater intrusion from south LCA

EP8 East Plug #8 PLUG CHANNEL Plug bayou L'eau Bleu to prevent recirculation of water from ES2 LCA

ER1 East Gated Structure #1 FLOOD GATES W/VARIABLE CREST OUTFALL Retain freshwater; prevent saltwater intrusion CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

ES2 East Diversion Structure #2 PUMP Pump water from GIWW to Grand Bayou LCA

EX1 East Removal #1 WEIR REMOVAL

Increase water movement through canal - distribute fresh water from Grand

Bayou CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

EX2 East Removal #2 PLUG REMOVAL

Increase water movement through canal - distribute fresh water from Grand

Bayou/St. Louis Canal CWPPRA - GRAND BAYOU/GIWW FRESHWATER DIVERSION (TE-10)

CC1 Central Culvert #1 BOX CULVERT Increase volume of water moving past constriction in GIWW LCA

CC2 Central Culvert #2 BOX CULVERT Increase volume of water moving past constriction in GIWW LCA

CC3 Central Culvert #3 GATED CONTROL STRUCTURE

Increase fresh water delivery from HNC to Bayou Grand Caillou/Lake

Boudreaux LCA

CC4 Central Culvert #4 GATED CONTROL STRUCTURE

Increase fresh water movement from HNC to Bayou Grand Caillou/Lake

Boudreaux LCA

Feature ID Feature Name Description Purpose Source

CC5 Central Culvert #5 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC6 Central Culvert #6 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC7 Central Culvert #7 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC8 Central Culvert #8 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC9 Central Culvert #9 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC10 Central Culvert #10 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC11 Central Culvert #11 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC12 Central Culvert #12 24IN. X 40FT ALUMINUM FLAP-GATED CROSS DRAIN

Allow fresh water movement from north to south into North Lake Boudreaux

system

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC13 Central Culvert #13 SIX 10'X10' BOX CULVERTS WITH SLUICE GATES UNDER HWY 57

Increase fresh water movement from HNC/Bayou Grand Caillou to North Lake

Boudreaux

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC14 Central Culvert #14 THREE 48IN. FLAPGATES EACH WITH STOPLOG BAY

Allow fresh water movement from new conveyance channel to marshes to

north

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CC15 Central Culvert #15 TIMBER BOAT WEIR Prevent shortcircuiting of fresh water through the north/south GSP canal

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CD1 Central Dredge Channel #1 6000' OF CANAL DREDGING

Increase fresh water delivery from HNC to Bayou Grand Caillou/Lake

Boudreaux LCA

CD2 Central Dredge Channel #2 1000' OF CANAL DREDGING

Increase fresh water movement from HNC to Bayou Grand Caillou/Lake

Boudreaux LCA

CD3 Central Dredge Channel #3 4000' OF CANAL DREDGING

Increase fresh water movement from HNC to Bayou Grand Caillou/Lake

Boudreaux LCA

CD4 Central Dredge Channel #4 2000' OF CANAL DREDGING Increase volume of water moving past constriction in GIWW LCA

CD5 Central Dredge Channel #5 2000' OF CANAL DREDGING Increase volume of water moving past constriction in GIWW LCA

CD6 Central Dredge Channel #6

7000' OF CANAL DREDGING - NEW WATER CONVEYANCE

CHANNEL

Provide conveyance of water from Bayou Pelton enlargement to North Lake

Boudreaux marshes

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CD7 Central Dredge Channel #7 6000' OF CANAL DREDGING - BAYOU PELTON ENLARGEMENT

Increase fresh water movement from HNC to Bayou Grand Caillou/North Lake

Boudreaux

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CL1 Central Lock Complex #1

MULTI-PURPOSE OPERATION OF PROPOSED HNC LOCK

COMPLEX

Optimize operation of lock complex for distribution of fresh water and

prevention of saltwater intrusion LCA

CLV1 Central Levee #1 5000' NEW FORCED DRAINAGE LEVEE Prevent potential flooding from proposed North Lake Boudreaux project

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CLV2 Central Levee #2 2000' NEW FORCED DRAINAGE LEVEE Prevent potential flooding from proposed North Lake Boudreaux project

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CM2 Central Marsh Berm #2 11,000 LINEAR FEET OF MARSH CREATION Retain fresh water in marshes to north; prevent saltwater intrusion from south LCA

CM3 Central Marsh Berm #3 9,000 LINEAR FEET OF MARSH CREATION Retain fresh water in marshes to north; prevent saltwater intrusion from south LCA

CM4 Central Marsh Berm #4 23,000 LINEAR FEET OF MARSH CREATION Retain fresh water in marshes to north; prevent saltwater intrusion from south LCA

CMC1 Central Marsh Creation #1 7 ACRES OF MARSH CREATION Disposal area for Bayou Pelton dredging

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CMC2 Central Marsh Creation #2 12 ACRES OF MARSH CREATION Disposal area for Bayou Pelton dredging

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

657
27

Table 4 - continued. Descriptions of proposed measures.

Feature ID Feature Name Description Purpose Source

CMC3 Central Marsh Creation #3 60 ACRES OF MARSH CREATION Disposal area for Bayou Pelton dredging

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CMC4 Central Marsh Creation #4 23 ACRES OF MARSH CREATION Disposal area for Bayou Pelton dredging

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CP1 Central Plug #1 CANAL PLUG

Retain fresh water in Lake Boudreaux basin; prevent saltwater intrusion into

Lake Boudreaux basin from Bayou Petit Caillou LCA

CP2 Central Plug #2 CANAL PLUG Prevent shortcircuiting of fresh water through the north/south GSP canal

CWPPRA - NORTH LAKE BOUDREAUX BASIN FRESHWATER INTRODUCTION

AND HYDROLOGIC MANAGEMENT (TE-32a)

CS1 Central Diversion Structure #1 BOX CULVERT WITH SLUICE GATES

Increase fresh water movement from HNC to Bayou Grand Caillou/Lake

Boudreaux LCA

CT1 Central Terracing #1 360 ACRES OF TERRACING Retain fresh water and prevent saltwater intrusion

CWPPRA - SOUTH TERREBONNE PARISH MARSH TERRACING (PPL 15

Candidate)

CT2 Central Terracing #2 40 ACRES OF TERRACING Retain fresh water and prevent saltwater intrusion

CWPPRA - SOUTH TERREBONNE PARISH MARSH TERRACING (PPL 15

Candidate)

CT3 Central Terracing #3 110 ACRES OF TERRACING Retain fresh water and prevent saltwater intrusion

CWPPRA - SOUTH TERREBONNE PARISH MARSH TERRACING (PPL 15

Candidate)

CT6 Central Terracing #6 70 ACRES OF TERRACING Retain fresh water and prevent saltwater intrusion

CWPPRA - SOUTH TERREBONNE PARISH MARSH TERRACING (PPL 15

Candidate)

CT7 Central Terracing #7 80 ACRES OF TERRACING Retain fresh water and prevent saltwater intrusion

CWPPRA - SOUTH TERREBONNE PARISH MARSH TERRACING (PPL 15

Candidate)

CT8 Central Terracing #8 150 ACRES OF TERRACING Retain fresh water and prevent saltwater intrusion

CWPPRA - SOUTH TERREBONNE PARISH MARSH TERRACING (PPL 15

Candidate)

CX1 Central Removal #1 REMOVAL OF TUNNEL UNDER GIWW Provide improved conveyance of water through GIWW LCA

WC1 West Culvert #1 MULTIPLE FLAPGATED 36" CULVERTS

Allow movement of lower salinity water from Lake Decade into marshes to

south CWPPRA - SOUTH LAKE DE CADE FRESHWATER INTRODUCTION (TE-39)

WC2 West Culvert #2 SHEETPILE STRUCTURE WITH FLAPGATED 48" OPENINGS

Allow movement of lower salinity water from Lake Decade into marshes to

south CWPPRA - SOUTH LAKE DE CADE FRESHWATER INTRODUCTION (TE-39)

WC3 West Culvert #3 SHEETPILE STRUCTURE WITH FLAPGATED 48" OPENINGS

Allow movement of lower salinity water from Lake Decade into marshes to

south CWPPRA - SOUTH LAKE DE CADE FRESHWATER INTRODUCTION (TE-39)

WD1 West Dredge Channel #1 2000' OF CANAL DREDGING Allow more efficient movement of water from Minors Canal to Lake Decade CWPPRA - CENTRAL TERREBONNE FRESHWATER ENHANCEMENT (TE-66)

WD2 West Dredge Channel #2 35,000' OF CANAL DREDGING

Allow more efficient movement of fresh water from Bayou Penchant to

southeast Penchant Basin marshes LCA

WD3 West Dredge Channel #3 16,000' OF GIWW DREDGING Eliminate constriction in GIWW LCA

WD4 West Dredge Channel #4 2700' OF CANAL DREDGING

Allow movement of lower salinity water from Lake Decade into marshes to

south CWPPRA - SOUTH LAKE DE CADE FRESHWATER INTRODUCTION (TE-39)

WP1 West Plug #1 CANAL PLUG Retain fresher water and prevent saltwater intrusion CWPPRA - CENTRAL TERREBONNE FRESHWATER ENHANCEMENT (TE-66)

WO1 West Shoreline Protection #1 50,000' OF SHORELINE PROTECTION Protect Penchant basin marshes from GIWW flows/wave wash

CWPPRA - GIWW BANK RESTORATION OF CRITICAL AREAS IN TERREBONNE

(TE-43)

WO2 West Shoreline Protection #2 50,000' OF SHORELINE PROTECTION Protect Penchant basin marshes from increased project-related flows LCA

WS1 West Diversion Structure #1 GATED BOX CULVERTS Increase flow to GIWW by moving water through Lake Palourde LCA

WS2 West Diversion Structure #2 GATED BOX CULVERTS

Increase flow from Atchafalaya River to GIWW by moving water from Bayou

Shaffer to the Avoca Island Cutoff/Bayou Chene LCA

WS3 West Diversion Structure #3 GATED BOX CULVERTS

Increase flow from Atchafalaya River to GIWW by moving water from Bayou

Shaffer to the Avoca Island Cutoff/Bayou Chene LCA

WS4 West Diversion Structure #4 GATED BOX CULVERTS

Increase flow from Atchafalaya River to GIWW by moving water from Bayou

Shaffer to the Avoca Island Cutoff/Bayou Chene LCA

WW2 West Weir #2 ROCK BARGE BAY Constrict Grand Pass to minimize water exchange CWPPRA - CENTRAL TERREBONNE FRESHWATER ENHANCEMENT (TE-66)

EVALUATION OF ALTERNATIVE PLANS

Unless otherwise stated, the results presented below pertain to the low SLR scenario. Because of

the study schedule time constraints, the process of editing and correcting benefit estimates for

this very complex project could not be fully completed prior to the deadline for report

preparation. Consequently, the information provided below contains some errors. The net

benefits (in AAHUs) provided below are without project-related impacts to estuarine dependent

fisheries via WVA variable 6 (Table 5). Benefits in net TY50 wetland acres, are presented in

Table 6. A listing of all WVA variables is available in the Supplemental EIS.

Based on the high construction and operation/maintenance costs of the pumping alternatives

(Alts), Alts 4 and 5, those alternatives were eliminated from further consideration. Likewise,

Alt3 exceeded the cost limit and was also eliminated. Because the most beneficial alternative

within the cost limit is Alt2, it was selected as the Tentatively Selected Plan (TSP).

The Avoca Island Cutoff Channel, Bayou Chene, and the GIWW serve as a conduit carrying

Atchafalaya River freshwater across the entire Terrebonne Basin, and into the Barataria Basin

(Figure 14). Alternatives 3 and 6, are the only alternatives that would introduce additional water

from the river into the Avoca Island Cutoff Channel via a water control structure (measure

WS4). To avoid exacerbating the existing backwater flooding problem for communities east of

Morgan City, the WS4 structure was assumed to discharge water only when Morgan City stages

were less than +4.0 feet. Consequently the structure was assumed not to operate during peak

stages on the lower Atchafalaya River (Table 7). The size of the WS4 structure was limited to

avoid excessive costs and only one structure size was evaluated. Given the average February

658
28

Table 5 Net benefits for project alternatives, in AAHUs (without fisheries impacts).

Table 6. Benefits for project alternatives, in net TY50 wetland acres.

Diversion Influence Area Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 Alt 8

E2-E4 0 0 0 0 0 0 0

F2 0 0 0 0 0 0 0

A6,A7,L.Pagie 7,887 8,018 7,783 7,932 862 851 667

B6,B7 2,789 2,833 2,766 2,816 2,191 2,190 2,336

Bayou Dulac -260 -252 -266 849 1,433 1,312 -418

C2-C7 841 855 757 765 -63 -48 847

C9 595 602 559 567 0 0 398

G1-G5 -253 -253 -253 -253 0 0 0

G2,G3,G6(G7) 4,823 4,880 7,698 7,700 2,176 0 3,964

Palm-Creole 0000000

C11-C14 -6,527 -6,508 -6,550 -6,525 -6,953 -6,956 -6,781

SUBTOTAL 9,895 10,174 12,495 13,850 -354 -2,651 1,013

Diversion Independent Measures

WD2 -319.0 -319.0 -319.0 -319.0

WO2 375.0 375.0 375.0

CD1 -3.4 -3.4 -3.4 -3.4 -3.4

CD3 -7.6 -7.6 -7.6 -7.6

CD7 -6.4 -6.4 -6.4 -6.4 -6.4

CT1,6,7,8 59.0 59.0 59.0 59.0

EM3 51.2 51.2

ED5 -14.1 -14.1 -14.1 -14.1 -14.1 -14.1

SUBTOTAL -240.3 134.7 -291.5 83.5 360.9 0.0 -23.9

TOTAL 9,654.8 10,308.4 12,204.0 13,933.6 7.1 -2,650.7 989.2

Diversion Influence Area ALT 2 ALT 3 ALT 4 ALT 5 ALT 6 ALT 7 ALT 8

E2-E4 -1.90 -1.90 -1.90 -1.90 0.01 0.00 0.00

F2 -12.80 -12.80 -11.83 -11.83 2.26 0.16 -12.89

A6,A7,L.Pagie 2132.48 2154.16 2118.62 2313.35 285.97 429.54 259.06

B6, B7 821.89 871.74 613.15 614.02 782.43 797.29 728.92

Bayou Dulac -267.01 -265.74 -230.17 12.39 98.96 69.57 -299.56

C2-C7 391.10 393.69 373.08 376.54 0.00 0.00 393.29

C9 260.75 262.93 249.73 252.05 0.00 0.00 209.16

G1-G5 -216.52 -216.38 -210.49 -210.49 0.00 0.00 0.00

G2,G3,G6 (G7) 1189.93 1202.70 2444.33 2444.54 610.78 -40.94 938.24

Palm-Creole 0.00 0.00 0.00 0.00 0.00 0.00 0.00

C11-C14 -924.04 -920.94 -931.14 -926.24 -1012.06 -1012.42 -991.64

SUBTOTAL 3373.87 3467.46 4413.39 4862.44 768.35 243.20 1224.58

Diversion Independent Measures

WD2 -164.73 -164.73 -164.73 -164.73 0.00 0.00 0.00

WO2 0.00 11.97 0.00 11.97 11.97 0.00 0.00

CD1 -1.22 -1.22 -1.22 -1.22 0.00 0.00 -1.22

CD3 -2.64 -2.64 -2.64 -2.64 0.00 0.00 0.00

CD7 -1.30 -1.30 -1.30 -1.30 0.00 0.00 -4.62

CT1,6,7,8 18.63 18.63 18.63 18.63 0.00 0.00 0.00

EM3 1.83 1.83 0.00 0.00 0.00 0.00 0.00

ED5 -4.55 -4.55 -4.55 -4.55 -4.55 0.00 -4.55

SUBTOTAL -153.98 -142.01 -155.80 -143.84 7.42 0.00 -10.39

TOTAL 3,219.90 3,325.45 4,257.59 4,718.61 775.77 243.20 1,214.19

659
29

Figure 14. Locations along the GIWW, HNC, and Grand Bayou where predicted discharges

were obtained.

Table 7. Average monthly WS4 discharge into the Avoca Island Cutoff Channel.

Alt3

TY1

Alt3

TY10

Alt6

TY1

Alt6

TY10

Jan 2,483 2,588 2,475 2,592

Feb 3,504 3,649 3,499 3,660

Mar 107 113 103 110

Apr 112 118 109 116

May 0 0 0 0

Jun 57 60 55 59

Jul 2,275 2,372 2,267 2,374

Aug 801 840 788 832

Sep 782 821 769 812

Oct 725 762 712 753

Nov 480 506 465 496

Dec 971 1,017 958 1,010

FWOP Avoca Island Cutoff Channel discharge of 20,883 cubic feet per second (cfs), the WS4

structure would provide an additional 17.5% discharge (cfs). From the analysis conducted, it can

not be determined where this additional water goes. Without sensitivity analysis, the benefits

provided by this additional freshwater cannot be conclusively determined. However, inspection

of the available data suggests that minimal benefits are provided for this magnitude of additional

freshwater input.

The tentatively selected plan (TSP) does not does not include measure WS4. Instead, the TSP

focuses primarily on improving the distribution of existing freshwater. However, the TSP

includes measures to eliminate the GIWW constriction between Bayou Black and Bay Wallace

(measure WD3), plus a system of culverts in downtown Houma (measures CC1, CC2, and CD4)

660
30

to bypass the GIWW constriction at the Bayou Terrebonne junction. Those measures are

intended to passively increase the supply of GIWW freshwater to the central and eastern study

area.

TSP TY1 flows are greater than TY1 FWOP flows along the entire GIWW conduit (Tables 8a

and 8b), except that less water enters the Barataria Basin under the TSP due to increased

discharge from the GIWW southward into the Grand Bayou system. The TSP-related GIWW

flow increases in the Penchant area may be related to the combined effects of increased

discharge from Bayou Penchant (measure WD2), the GIWW constriction removal

Table 8a. GIWW flows in cfs for FWOP and Alt2 FWP.

Table 8b. GIWW and Grand Bayou Canal flows in cfs for FWOP and Alt2 FWP.

(measure WD3), bank armoring measures (WO2 and WO1), the GIWW constriction by-pass in

Houma, the Grand Pass plug (measure WP1), the enlargement of Grand Bayou Canal in the

eastern study area, and possibly other measures. GIWW flow increases in the central and eastern

study areas may also be due to Grand Bayou enlargement, the GIWW constriction by-pass in

Houma and other measures.

FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP

TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10

Jan 6,044 6,598 6,396 6,398 2,549 3,005 2,914 3,176 1,579 1,953 1,827 1,977 1,509 1,372 1,968 1,487 -235 -1,119 -203 -1,273

Feb 7,957 8,791 8,447 8,452 3,101 3,820 3,619 4,121 1,819 2,421 2,180 2,500 1,834 1,603 2,504 1,732 -352 -1,722 -307 -1,953

Mar 9,481 10,538 10,080 10,088 3,541 4,468 4,180 4,873 2,011 2,794 2,461 2,917 2,092 1,787 2,932 1,927 -445 -2,202 -389 -2,494

Apr 9,374 10,416 9,966 9,973 3,510 4,423 4,141 4,821 1,998 2,768 2,441 2,887 2,074 1,774 2,902 1,914 -439 -2,168 -384 -2,457

May 11,536 12,893 12,283 12,293 4,133 5,343 4,937 5,888 2,269 3,296 2,839 3,479 2,441 2,035 3,508 2,191 -571 -2,850 -501 -3,225

Jun 10,437 11,634 11,106 11,114 3,817 4,876 4,533 5,346 2,131 3,028 2,637 3,178 2,254 1,902 3,200 2,050 -504 -2,503 -441 -2,834

Jul 5,654 6,151 5,978 5,980 2,437 2,840 2,771 2,984 1,530 1,858 1,756 1,870 1,443 1,325 1,858 1,437 -211 -996 -182 -1,135

Aug 2,890 2,983 3,015 3,013 1,639 1,663 1,752 1,619 1,183 1,182 1,247 1,114 974 992 1,083 1,084 -41 -125 -33 -152

Sep 2,855 2,942 2,977 2,975 1,629 1,648 1,739 1,601 1,178 1,173 1,240 1,104 968 988 1,073 1,079 -39 -114 -31 -140

Oct 2,749 2,821 2,748 2,861 1,598 1,603 1,600 1,549 1,165 1,147 1,119 1,075 950 975 1,111 1,065 -33 -81 -37 -102

Nov 2,288 2,293 2,267 2,367 1,466 1,407 1,409 1,321 1,107 1,035 1,020 949 872 919 974 1,006 -5 65 -11 62

Dec 3,209 3,349 3,357 3,356 1,731 1,799 1,870 1,776 1,223 1,260 1,305 1,201 1,028 1,030 1,173 1,124 -61 -226 -50 -266

Ave. 6,206 6,784 6,552 6,573 2,596 3,075 2,955 3,256 1,600 1,993 1,839 2,021 1,537 1,392 2,024 1,508 -245 -1,170 -214 -1,331

GIWW east of Larose

Grand Bayou Canal

GIWW west of Houma GIWW east of Houma GIWW east of Company Canal (-flow to south)

FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP

TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10

Jan 13,697 13,778 14,154 14,309 10,892 11,199 11,367 11,731 7,482 8,669 7,830 9,031 3,890 4,119 4,099 4,175

Feb 16,314 16,372 16,909 17,077 13,700 13,991 14,320 14,691 8,803 10,145 9,244 10,570 5,066 5,362 5,352 5,403

Mar 18,398 18,438 19,103 19,282 15,936 16,214 16,671 17,048 9,855 11,320 10,370 11,795 6,002 6,351 6,350 6,381

Apr 18,253 18,294 18,950 19,128 15,780 16,059 16,507 16,884 9,781 11,238 10,292 11,710 5,937 6,282 6,280 6,313

May 21,210 21,224 22,061 22,256 18,951 19,213 19,842 20,228 11,274 12,905 11,890 13,448 7,264 7,686 7,695 7,701

Jun 19,707 19,735 20,480 20,666 17,340 17,610 18,147 18,529 10,515 12,058 11,078 12,564 6,590 6,973 6,976 6,996

Jul 13,164 13,250 13,593 13,745 10,320 10,630 10,766 11,128 7,213 8,369 7,542 8,718 3,651 3,866 3,844 3,925

Aug 9,383 9,502 9,614 9,745 6,264 6,598 6,501 6,851 5,305 6,237 5,499 6,495 1,953 2,071 2,034 2,151

Sep 9,334 9,454 9,563 9,694 6,212 6,546 6,447 6,797 5,280 6,210 5,473 6,467 1,931 2,048 2,011 2,128

Oct 9,189 9,310 9,400 9,540 6,056 6,391 6,280 6,632 5,207 6,128 5,441 6,381 1,866 1,979 1,969 2,060

Nov 8,559 8,686 8,742 8,874 5,380 5,719 5,573 5,919 4,889 5,772 5,107 6,011 1,583 1,680 1,675 1,764

Dec 9,819 9,935 10,073 10,207 6,732 7,063 6,993 7,345 5,525 6,483 5,735 6,752 2,149 2,278 2,243 2,356

Ave. 13,919 13,998 14,387 14,544 11,130 11,436 11,618 11,982 7,594 8,795 7,958 9,162 3,990 4,225 4,279 4,279

Avoca Island Cutoff W of Avoca Is Bayou Chene E of Penchant GIWW east of Bay Wallace GIWW middle of Penchant Basin

661
31

The Morganza to the Gulf Hurricane Protection Project was assumed to become functional in

TY10. FWOP HNC Lock operations, were simulated as lock closure during the months of

October and November for the purpose of saltwater intrusion abatement. Otherwise, the

Morganza Project was assumed to have no effects. FWP HNC Lock Multi-Purpose Operations

(MPO), were simulated as the year-round closure of the HNC Lock (beginning in TY10). The

HNC Lock operations appear to generally increase eastward GIWW flows under both FWOP

and FWP. The Morganza Projects GIWW floodgate east of Bayou Lafourche was not included

in the hydraulic model, hence, effects of that structure on area hydrology were not simulated.

Depending on its size and depth, that floodgate might further impede GIWW flow entering the

Barataria Basin and increase freshwater flow down Grand Bayou.

FWOP and TSP flows through un-improved channels that typically carry GIWW southward are

provided (Table 9). The predicted FWOP northward flow in both Bayou Copasaw and Minors

Canal is contrary to observed flow direction. Consequently, the predicted TSP northward flows

are also questionable. Predicted Minors Canals flows were among several discharge

measurements used to calculate FWP flow increases and associated TSP wetland benefits in

subunits A6, A7, Lake Pagie. Southward freshwater discharge in Grand Bayou would be

substantially increased there under the TSP and other alternatives which include those same

channel enlargement measures (Table 8b).

Table 9. FWOP and TSP discharge in un-improved channels connected to the GIWW.

Normally, the majority of GIWW freshwater entering Houma exits to the Gulf via the HNC.

Under the TSP, the additional discharges from the Bay Chene/GIWW system via measure WD2

and the Grand Bayou enlargement measures, may be responsible for the slight TY1 reduction in

southward HNC flows (Table 10). Although it can not be determined from the presented

information, measure WD3 (enlargement of the GIWW constriction between Bayou Black and

Bay Wallace) likely compensates for those additional discharges from the GIWW, thus

minimizing FWP flow reductions to the HNC and elsewhere. Once the Morganza system

becomes operational in TY10, the FWOP HNC Lock would be closed during October and

November for saltwater intrusion abatement. Those Lock closures substantially reduce exchange

through the HNC Lock during those months (as per flows at the HNC south of BGC). The MPO

FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP

TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10

Jan 1,614 2,456 2,622 2,539 1,004 1,004 1,087 1,031 -112 -199 -171 -181 -200 839 -154 -110

Feb 1,629 2,922 3,125 3,022 1,283 1,256 1,414 1,330 -222 -362 -312 -336 -305 997 -235 -162

Mar 1,642 3,293 3,525 3,407 1,505 1,457 1,674 1,569 -309 -491 -425 -460 -388 1,123 -300 -204

Apr 1,641 3,268 3,497 3,380 1,489 1,443 1,656 1,552 -303 -482 -417 -451 -382 1,114 -296 -201

May 1,659 3,794 4,066 3,926 1,804 1,728 2,025 1,891 -427 -666 -577 -626 -501 1,292 -388 -260

Jun 1,650 3,527 3,777 3,649 1,644 1,583 1,838 1,719 -364 -573 -496 -537 -440 1,202 -341 -230

Jul 1,611 2,361 2,519 2,440 947 953 1,020 970 -89 -166 -142 -150 -179 807 -137 -100

Aug 1,588 1,688 1,793 1,742 544 589 548 537 70 69 63 74 -27 579 -19 -24

Sep 1,588 1,679 1,783 1,733 539 584 541 532 72 72 65 77 -25 576 -18 -23

Oct 1,587 1,653 1,751 1,706 523 570 464 515 78 81 79 86 -20 567 -19 -20

Nov 1,583 1,541 1,635 1,590 456 509 384 443 104 121 110 123 6 529 1 -8

Dec 1,591 1,765 1,876 1,823 591 631 602 587 51 42 39 48 -45 605 -33 -33

Ave. 1,615 2,496 2,664 2,580 1,027 1,025 1,104 1,056 -121 -213 -182 -194 -209 852 -162 -115

Bayou Pechant mouth

(+flow to south)

Bayou Copasaw head

(-flow to south)

Minors Canal

(+flow to south)

Company Canal south of GIWW

(-flow to south)

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32

result in a substantial year-round reduction in southward flows (see Table 10, HNC south of

BGC, FWP TY10).

Table 10. FWOP and TSP discharge at locations on the HNC

Measure WD2 (the enlargement of the relic Carencro Bayou), a 140-foot-wide freshwater

conveyance channel from Bayou Penchant to Little Carencro Bayou (Figure 15), provides the

first major freshwater introduction opportunity from the Bayou Chene/GIWW conduit.

Consequently, WD2 captures more discharge than any other gravity-flow freshwater introduction

measure (up to 4,100 cfs), and hence, it provides more benefit than any other evaluated measure.

Although WD2 and all freshwater introduction measures were evaluated as providing no

sediment input benefits, the occasional presence of turbid water in Bayou Penchant suggests that

some sediment accretion benefits might be possible at times in the area influenced by WD2. The

319-acre construction impact for WD2 would be located in the Carencro subunit, and was

assessed independently of the freshwater introduction benefits, which were assumed to be

confined to the A6, A7, and Lake Pagie subunits. FWOP salinity modeling incorrectly

incorporated salinity reduction effects associated with an assumed smaller FWOP WD2 channel.

Consequently, the FWP salinity reduction benefits for the affected area may underestimate WD2

salinity lowering effects.

Alt7 does not include measure WD2. The resulting Alt7 benefits to the A6, A7, Lake Pagie area

of 430 AAHUs are much less than those alternatives which include WD2. This illustrates the

significant benefit associated with measure WD2. Measure WD2 did not include a salinity

control structure to preclude northward saltwater intrusion during periods of low Atchafalaya

River discharge. However, predicted Carencro subunit average monthly FWP salinities did not

differ from FWOP average monthly salinities. The other major project TSP (Alt2) effect in the

western study area is the anticipated salinity reduction associated with the combined effects of

the proposed Grand Pass plug (measure WP1), in combination with the increased freshwater via

WD2 (Table 11).

FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP

TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10 TY1 TY1 TY10 TY10

Jan 4,329 4,140 4355 3261 5,206 5,468 5357 3417 5,128 5,592 5422 1773

Feb 5,269 5,207 5260 4234 5,950 6,021 6039 3946 5,523 6,017 5760 1874

Mar 6,017 6,056 5981 5009 6,542 6,462 6582 4368 5,838 6,356 6029 1954

Apr 5,965 5,997 5931 4955 6,501 6,431 6544 4338 5,816 6,333 6011 1948

May 7,027 7,202 6953 6054 7,341 7,056 7314 4936 6,262 6,813 6393 2062

Jun 6,487 6,590 6434 5495 6,914 6,739 6923 4632 6,035 6,569 6199 2004

Jul 4,138 3,923 4171 3062 5,054 5,355 5218 3309 5,048 5,505 5353 1753

Aug 2,780 2,382 2863 1656 3,979 4,556 4233 2545 4,477 4,890 4864 1607

Sep 2,763 2,362 2847 1638 3,965 4,545 4221 2535 4,470 4,882 4858 1605

Oct 2,711 2,303 1812 1584 3,924 4,515 2259 2505 4,448 4,859 1527 1600

Nov 2,484 2,046 1578 1350 3,745 4,381 2087 2378 4,353 4,756 1510 1575

Dec 2,937 2,560 3014 1819 4,103 4,648 4347 2633 4,543 4,961 4921 1624

Ave. 4,409 4,231 4,267 3,343 5,269 5,515 5,094 3,462 5,162 5,628 4,904 1,782

HNC head HNC @ pontoon bridge HNC south of BGC

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33

Figure 15. Location of measure WD2.

Table 11. FWOP and TSP (Alt2) predicted average annual salinities in the subunits above the

Grand Pass plug.

Lost Lake subunit A8 subunit

TY1 TY10 TY50 TY1 TY10 TY50

(ppt*) (ppt) (ppt) (ppt) (ppt) (ppt)

FWOP 7.71 7.72 7.44 FWOP 3.43 3.36 2.98

Alt2 5.19 4.95 4.17 Alt2 2.38 2.01 1.46

* parts per thousand

Alternatives 2-5 and Alt8 included the CWPPRA programs North Lake Boudreaux Basin

Freshwater Introduction Project (TE-32a). This project would seasonally introduce HNC

freshwater into the upper basin marshes via enlargement of Bayou Pelton and construction of a

new conveyance channel (Figure 16). The associated freshwater introduction benefits to the

north Lake Boudreaux Basin marshes (subunits C2 through C7), are fairly consistent across

alternatives (Tables 5 and 6), suggesting that the water introduced into this area from the upper

HNC tends to be fairly independent of other measures. Because the Grand Bayou pumping

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34

alternatives (Alts 4 and 5) draw large volumes of water out of the GIWW, it appears they may

reduce the availability of freshwater to the HNC as indicated by the slightly reduced C2-C7

benefits for those alternatives. Salinity effects associated with freshwater inputs into the basin at

Bayou Pelton and Bayou Butler (measure CS1), in combination with the Robinson Canal plug

(measure CP1), and HNC Lock operations, appear to occur throughout all but the southeastern

portion of the basin (Table 12). The increased salinity in the southwestern portion of the basin

may be due to insufficient model-predicted mixing of water masses. Despite near basin-wide

salinity reductions, the CWPPRA Bayou Pelton freshwater introduction benefits are limited to

the upper basin (subunits C2-C7), and the benefits of the Bayou Bulter introduction are limited to

subunit C9 (Figure 16).

Figure 16. Lake Boudreaux Basin freshwater introduction sites and locations of salinity outputs.

TY1 modeling indicates that Bayou Dulac serves to discharge water from the basin under both

FWOP and the TSP. Although the FWP waters discharged from the basin range from 7 to 8 ppt,

the HNC receiving area apparently increased to over 9 ppt. In TY10, Bayou Dulac flow under

both FWOP and the TSP are reversed such that Bayou Dulac provides net inflow to the basin

665
35

Table 12. Lake Boudreaux Basin predicted salinities, FWOP and TSP (Alt2).

Station "C3" Station "C7"

Station "C10

North"

Station "C10

West"

Station "C10

South"

FWOP Alt2 FWOP Alt2 FWOP Alt2 FWOP Alt2 FWOP Alt2

(ppt) (ppt) (ppt) (ppt) (ppt) (ppt) (ppt) (ppt) (ppt) (ppt)

TY1 6.70 1.59 7.55 6.50 8.66 6.12 9.21 7.39 10.52 10.01

TY10 6.71 1.24 7.55 7.21 8.64 6.28 9.17 8.37 10.49 11.17

TY50 6.82 1.86 7.95 7.59 8.97 6.73 9.45 8.26 10.73 10.78

from the HNC. Nevertheless, average annual salinities within portions of the HNC at Bayou

Grand Caillou and at Falgout Canal exhibit FWP salinity increases (Table 13). Those salinity

increases also occur within Falgout Canal and in eastern portions of subunit A6. The HNC

salinity increases might be explained by saltwater moving northward through the locks sluice

gates during the late summer and early fall. The cause of this FWP salinity increase needs to be

confirmed. If it is related to operation of the lock sluice gates, revised sluice gate operations

should be evaluated to preclude this saltwater intrusion effect.

Table 13. FWOP and TSP (Alt2) predicted salinities north of the HNC lock.

Because of the uncertainty regarding the cause of this effect, the benefits of the MPO are

difficult to determine. Model parameters governing mixing within the Lake Boudreaux Basin

should also be re-examined to confirm that the TY1 mixing value(s) reflect conditions in a

relatively shallow open water body subject to tidal currents and considerable wind/wave action.

Details regarding the size and operation of sluice gates should be provided and the effects of

alternative sluice gate operations should be evaluated.

The estimation of benefits associated with the HNC Lock operation were also hampered to an

extent by the accidental omission of the Morganza Projects 2 freshwater introduction structures

located along the reach of Falgout Canal between Bayou DuLarge and the HNC. Since then,

Corps modelers have estimated that the maximum combined discharge of those structures would

be approximately 1,500 cfs (after the Morganza system becomes operational in TY10). The

benefits for areas B6 and B7 disclosed in this report do not include the effects associated with the

Falgout Canal structures. Preliminary evaluations suggest that benefits to areas B6 and B7

would increase with the additional freshwater input. Because MPO would increase discharge

down lower Bayou Grand Caillou (and into B6 via the Falgout Canal structures), it would also

reduce freshwater discharge below the Lock. Given that salinity monitoring conducted by the

Service has demonstrated that the lateral distribution of freshwater into marshes adjoining the

lower HNC is rather limited due apparently to the efficiency and size of the lower HNC, the

FWOP Alt2 FWOP Alt2 FWOP Alt2 FWOP Alt2

(ppt) (ppt) (ppt) (ppt) (ppt) (ppt) (ppt) (ppt)

TY1 9.21 7.39 3.62 5.41 8.14 9.44 1.24 2.94

TY10 9.17 8.37 3.17 3.91 8.26 9.32 1.03 2.24

TY50 9.45 8.26 2.84 4.18 8.80 9.68 0.86 2.21

Station "C10 West"

Station "HNC @

Falgout Canal"

Station "HNC A

Bayou Grand Station "A6 east"

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36

Service expected the freshwater deprivation effects to marshes in this area to be minor.

According to the methods used, however, those impacts were substantial. Although it is possible

that the predicted results are more accurate than initially thought, there are a number of

shortcomings that may have resulted in an overestimation of those impacts.

For the hydraulic model to accurately represent this landscape, the model grid should depict the

channels, natural bayou banks and other landforms that influence area hydrology. If the model

accurately represented area bathymetry/topography, then model results might be used to define

an impact area. Because of the shortened study schedule, this more desirable approach could not

be taken. Instead, a fairly large impact area was defined (subunits C11 through C14). Because

the degree of impact likely decreases with distance from the HNC, use of an excessively large

impact area may contribute to an overestimation of impacts.

Wetland acreage losses resulting from freshwater deprivation were quantified by running the

SAND2 model in reverse so that net freshwater input reductions were input as flow increases.

The sign of the resulting positive wetland acreage gains was then changed to a negative (wetland

loss). In this very atypical use of the SAND2 model, the results are subject to an increased

degree of uncertainty.

The average TY10 monthly Alt2 reduction in freshwater flow south of the HNC Lock is 3,122

cfs (Table 10). However, lower Bayou Grand Caillou receives only an additional 1,277 cfs.

Those increased flows account for only 41% of the flow lost to the lower HNC. If the model has

the unaccounted 1,845 cfs returning to the HNC through the marsh, then impacts to marshes

below the HNC are certainly overestimated. Conversely, if the uncounted for flow is entering

areas B6 and B7 through the marsh, then the benefits provided by that flow are not captured in

the current analysis. Because of the limited study schedule, there was not sufficient time to

address this issue. Consequently, the predicted benefits/impacts associated with the MPO are

subject to a high degree of uncertainty.

TSP-related freshwater introduction benefits to eastern study area marshes are limited to Bayou

Terrebonne, St. Louis Canal, and Grand Bayou. Although Bayou Terrebonne connects directly

to the GIWW, the majority of GIWW water enters Bayou Terrebonne via Company Canal. Most

of the fresh water flowing southward down Bayou Terrebonne exits the bayou via Humble Canal

to enter subunits E2, E3, and E4. Some Bayou Terrebonne flows may continue down Bayou

Terrebonne into subunit D3. However, the increased discharge from the Lake Boudreaux Basin

via Boudreaux Canal is likely the primary cause of the observed FWP salinity decreases there.

At both TY1 and TY10, the TSP Bayou Terrebonne discharge north of Humble Canal is reduced

compared to FWOP. Although this effect might be correct, hydraulic model calibration was

difficult in this area as the model was calibrated without simulating the actual Bayou Terrebonne

floodgate closure for high water conditions which occurred during the period when model

calibration data were collected. Although this issue has increased uncertainty regarding project

benefits in this area, the very high loss rates in this area would likely overwhelm any small to

medium freshwater flow increase.

Although the St. Louis Canal once allowed a small volume of GIWW freshwater to flow

southward into Bayou Pointe au Chene, recently constructed plugs have eliminated those

667
37

freshwater inputs. Model results did not include the effects of those plugs, and have incorrectly

indicated the presence of FWOP flows. Additionally, the TSP was determined to reduce those

FWOP freshwater inputs. This FWP flow reduction may be related to model issues regarding the

influence of the larger volumes being introduced via Grand Bayou. Use of the provided FWOP

and FWP model-predicted flows result in a predicted FWP reduction of freshwater inputs into

areas G1and G5. Hence, this measure was determined as causing net wetland loss due primarily

to channel construction impacts. There was not sufficient time to correct this and other errors.

The proposed enlargement of Grand Bayou is the second most beneficial measure(s) evaluated.

Much of the GIWW flow that would otherwise continue eastward into the Barataria Basin is

redirected southward into the Grand Bayou system (Table 8b). Wetland impacts associated with

channel enlargement initially result in TY1 impacts. However, benefits associated with the

freshwater introduction soon begin producing net benefits. Because there was insufficient time

to evaluate various alternative channel sizes and designs, only one enlargement design was

modeled. The design chosen for evaluation in this study, an east-branch 7,500 square foot

cross-section channel which was the preferred design among the alternative channels evaluated

under the CWPPRA programs Central and East Terrebonne Freshwater Delivery Project.

However, modeling difficulties experienced under the CWPPRA effort may have affected results

to the extent that selection of a preferred design would be inadvisable. Given this situation, it

was assumed the ARTM modeling would correct and re-evaluate alternative channel designs, but

the ARTM study schedule did not allow for that. Also, the channel design evaluated under the

ARTM modeling included dredging measure ED7, which was not part of the CWPPRA design.

Hence, the ARTM-determined construction impacts are in excess of that needed as the ARTM

design included more channel enlargements than did the CWPPRA-preferred design.

Consequently, without further evaluation, it cannot be determined that the most cost-effective

and least damaging Grand Bayou alternative channel was selected.

Table 14. FWOP and FWP freshwater inputs into the Grand Bayou system.

FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

TY1 TY1 TY1 TY1 TY1 TY1 TY1 TY1

(cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs)

Jan -235 -1,119 -1,152 -3,999 -3,999 -843 -235 -987

Feb -352 -1,722 -1,770 -3,999 -3,999 -1,276 -352 -1,514

Mar -445 -2,202 -2,203 -3,999 -3,999 -1,574 -445 -1,934

Apr -439 -2,168 -2,170 -3,999 -3,999 -1,551 -439 -1,905

May -571 -2,850 -2,850 -3,999 -3,999 -2,025 -571 -2,501

Jun -504 -2,503 -2,504 -3,999 -3,999 -1,784 -504 -2,198

Jul -211 -996 -1,027 -3,999 -3,999 -755 -211 -880

Aug -41 -125 -135 -3,999 -3,999 -131 -41 -118

Sep -39 -114 -123 -3,999 -3,999 -123 -39 -108

Oct -33 -81 -89 -3,999 -3,999 -99 -33 -79

Nov -5 65 60 -3,999 -3,999 5 -5 48

Dec -61 -226 -238 -3,999 -3,999 -203 -61 -206

Ave. -245 -1,170 -1,183 -3,999 -3,999 -863 -245 -1,032

Predicted freshwater inputs to Grand Bayou Canal (- flow to south)

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The Grand Bayou area FWP salinity reductions are proportional to the additional freshwater

input (Table 14). The pumping alternatives (Alts 4 and 5) would introduce the most additional

freshwater. In reality, however, pump discharge would likely have to greatly reduced or halted

during the fall months as pump operation would likely pull in brackish waters from the Barataria

Basin or elsewhere. Gravity flow alternatives would introduce up to 1,300 cfs of additional

freshwater to the Grand Bayou system.

The TSP and other gravity flow alternatives would result in FWP salinity reductions southward

through subunit G6 and into G7 (Table 15). However, the freshwater introduction influence area

was extended southward to include G7 only for the pumping alternatives (Alts 4 and 5), as the

G7 area experiences a more significant salinity lowering than for the gravity-flow alternatives.

Although the gravity flow alternatives would theoretically provide salinity reduction benefits to

area G7, the average annual salinity used in the WVA analysis (i.e., Variable 5) does not capture

those benefits as salinities ranging from 0 to 20 ppt are considered optimal and of equal

suitability for saline marshes.

Monthly salinity data also reveal that project-related channel enlargement may encourage

salinity increases during the fall months when Atchafalaya River inputs are at their lowest (Table

15). Those saltwater intrusion effects appear to be greatest near the northern end of the enlarged

channels (subunit G2) and least in areas south of the enlarged channel. Effects of FWP salinity

change for the brackish marshes of the Grand Bayou freshwater influence area would be

captured by the WVAs Variable 5 (average annual salinity value). Since optimal brackish

marsh average annual salinities range from 0 to 10 ppt in the brackish marsh WVA model, that

model does not capture many of the FWP salinity reduction effects for the G2, G3, and G6

influence areas (Table 16).

In the Grand Bayou marshes and other areas where wetland acreage declined rapidly during the

project life, a flaw in the application of the SAND2 model was discovered which causes an

overestimation of freshwater introduction benefits toward the end of the project life. Because

there was not sufficient time to correct this problem, the results presented here (Tables 5 and 6)

may overestimate the actual freshwater introduction benefits. The -40 AAHU benefit for area

G2,G3,G6 under Alt7 is also an error. This alternative does not include measures in the Grand

Bayou area, and therefore, there should be no benefits or impacts.

Alternatives 2 - 5 and alternative 8, include a plug on the Cutoff Canal (measure EP7) where it

was dredged through the Bayou Pointe au Chene ridge. Theoretically, this outfall management

feature would increase benefits to the upstream G2, G3, and G6 areas. However, the Cutoff

Canal plug would also reduce freshwater input benefits to the downstream subunit F2.

Consequently, F2 shows net impacts under alts 2-5, and Alt8 (Table 5). Those impacts were

generated using the SAND2 model in reverse as if freshwater were being introduced directly

into F2. However, the TY1 average annual FWOP F2 salinity of 16.0 ppt, and the FWP salinity

of 16.9 ppt illustrate that the plug does not appear to markedly affect F2 salinities. If nutrient

inputs would exhibit the same minimal changes due to the Cutoff Canal plug as the salinities,

then the SAND2 model-predicted impacts for area F2 may be overestimated.

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39

Table 15. FWOP and FWP monthly salinities for areas G2, G6, and G7.

Shaded cells indicate FWP salinity increases relative to FWOP.

TY1 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 3.87 3.49 3.02 2.07 2.02 2.85 3.87 3.85Feb 3.53 2.67 1.97 1.67 1.61 1.86 3.53 3.33Mar 3.26 2.01 2.00 1.36 1.35 1.99 3.26 2.91Apr 3.28 2.06 2.05 1.38 1.37 2.04 3.28 2.94May 2.90 1.12 1.12 0.93 0.93 1.19 2.90 2.35Jun 3.10 1.60 1.59 1.16 1.16 1.62 3.10 2.65Jul 3.94 3.66 3.23 2.15 2.10 3.05 3.94 3.96Aug 4.43 4.86 4.75 2.72 2.70 4.49 4.43 4.72Sep 4.44 4.87 4.77 2.73 2.71 4.51 4.44 4.73Oct 4.46 4.92 4.83 2.75 2.73 4.56 4.46 4.75Nov 4.54 5.12 5.08 2.85 2.83 4.80 4.54 4.88Dec 4.38 4.72 4.58 2.66 2.63 4.32 4.38 4.63Avg 3.85 3.42 3.25 2.04 2.01 3.11 3.85 3.81

TY10 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 4.08 3.77 3.73 2.03 2.02 3.01 3.93 3.69Feb 3.74 2.87 2.83 1.65 1.65 1.96 3.59 2.91Mar 3.47 2.16 2.15 1.36 1.36 2.15 3.32 2.30Apr 3.49 2.21 2.20 1.38 1.38 2.19 3.34 2.34May 3.11 1.20 1.20 0.96 0.96 1.31 2.96 1.46Jun 3.30 1.71 1.71 1.17 1.17 1.76 3.15 1.91Jul 4.15 3.95 3.91 2.10 2.09 3.22 4.00 3.85Aug 4.63 5.24 5.21 2.64 2.63 4.74 4.49 4.97Sep 4.64 5.26 5.22 2.65 2.64 4.76 4.49 4.99Oct 4.51 5.31 5.27 2.67 2.66 4.81 4.51 5.03Nov 4.59 5.52 5.49 2.76 2.75 5.07 4.59 5.22Dec 4.58 5.09 5.06 2.58 2.57 4.56 4.43 4.84Avg 4.02 3.69 3.66 2.00 1.99 3.29 3.90 3.63

TY50 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 5.00 4.59 4.43 2.50 2.48 4.35 4.73 3.94Feb 4.60 3.47 3.28 2.07 2.07 3.40 4.39 2.98Mar 4.28 2.57 2.55 1.74 1.73 2.65 4.13 2.21Apr 4.30 2.64 2.62 1.76 1.75 2.70 4.14 2.26May 3.85 1.37 1.37 1.28 1.28 1.63 3.77 1.17Jun 4.08 2.01 2.00 1.52 1.52 2.17 3.96 1.73Jul 5.08 4.82 4.67 2.59 2.57 4.54 4.80 4.13Aug 5.65 6.44 6.34 3.20 3.17 5.91 5.28 5.53Sep 5.66 6.46 6.36 3.21 3.18 5.93 5.29 5.54Oct 5.30 6.52 6.42 3.23 3.21 5.98 5.30 5.60Nov 5.39 6.79 6.70 3.33 3.31 6.21 5.39 5.83Dec 5.59 6.25 6.14 3.13 3.10 5.75 5.22 5.37Avg 4.90 4.50 4.41 2.46 2.45 4.27 4.70 3.86

G2 Salinities

TY1 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 11.29 8.68 8.26 1.76 1.76 8.73 11.29 8.75Feb 9.90 5.99 5.38 1.38 1.38 5.69 9.90 6.30Mar 8.79 3.86 3.85 1.09 1.08 5.18 8.79 4.34Apr 8.86 4.01 4.00 1.11 1.10 5.32 8.86 4.47May 7.29 0.97 0.97 0.68 0.68 2.46 7.29 1.70Jun 8.09 2.52 2.51 0.90 0.90 3.91 8.09 3.11Jul 11.57 9.23 8.85 1.84 1.83 9.35 11.57 9.25Aug 13.59 13.10 13.01 2.38 2.37 13.74 13.59 12.81Sep 13.61 13.15 13.06 2.39 2.38 13.79 13.61 12.85Oct 13.69 13.30 13.22 2.41 2.40 13.96 13.69 12.99Nov 14.03 13.95 13.92 2.50 2.49 14.69 14.03 13.58Dec 13.35 12.66 12.53 2.32 2.31 13.23 13.35 12.40Avg 11.17 8.45 8.30 1.73 1.72 9.17 11.17 8.55

TY10 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 11.71 9.06 9.00 1.85 1.84 8.84 11.21 8.92Feb 10.26 6.25 6.18 1.51 1.51 5.76 9.87 6.24Mar 9.10 4.02 4.01 1.25 1.25 5.28 8.81 4.11Apr 9.18 4.17 4.16 1.27 1.27 5.42 8.88 4.26May 7.53 1.00 1.00 0.90 0.90 2.53 7.37 1.23Jun 8.37 2.61 2.61 1.09 1.09 4.00 8.14 2.77Jul 12.01 9.64 9.57 1.91 1.91 9.47 11.49 9.46Aug 14.11 13.69 13.65 2.39 2.39 13.92 13.42 13.33Sep 14.14 13.75 13.70 2.40 2.39 13.97 13.45 13.38Oct 13.52 13.90 13.86 2.42 2.41 14.14 13.52 13.53Nov 13.84 14.58 14.54 2.50 2.49 14.89 13.84 14.17Dec 13.87 13.22 13.18 2.34 2.33 13.40 13.20 12.88Avg 11.47 8.83 8.79 1.82 1.82 9.30 11.10 8.69

TY50 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 13.08 10.36 9.83 3.38 3.38 11.25 12.57 10.29Feb 11.46 7.37 6.75 2.95 2.95 8.60 10.95 7.44Mar 10.16 4.98 4.91 2.61 2.60 6.58 9.65 5.17Apr 10.25 5.15 5.07 2.63 2.63 6.73 9.74 5.33May 8.42 1.77 1.77 2.14 2.14 3.76 7.91 2.11Jun 9.35 3.49 3.45 2.39 2.39 5.27 8.84 3.75Jul 13.41 10.97 10.46 3.46 3.46 11.79 12.90 10.88Aug 15.76 15.29 14.92 4.08 4.08 15.62 15.25 14.99Sep 15.79 15.34 14.98 4.09 4.08 15.67 15.28 15.05Oct 15.37 15.51 15.15 4.12 4.11 15.82 15.37 15.21Nov 15.77 16.23 15.89 4.22 4.21 16.46 15.77 15.89Dec 15.49 14.79 14.40 4.01 4.01 15.18 14.98 14.52Avg 12.86 10.10 9.80 3.34 3.34 11.06 12.44 10.05

G6 Average Salinities G7 Average Salinities

TY1 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 16.88 14.64 12.82 5.13 5.13 12.96 16.88 14.70Feb 14.53 11.09 8.35 4.53 4.53 8.45 14.53 11.27Mar 12.66 8.27 8.26 4.05 4.05 10.62 12.66 8.55Apr 12.79 8.46 8.46 4.08 4.08 10.79 12.79 8.74May 10.13 4.45 4.45 3.40 3.40 7.42 10.13 4.86Jun 11.48 6.49 6.49 3.75 3.75 9.13 11.48 6.83Jul 17.36 15.36 13.73 5.25 5.25 13.88 17.36 15.40Aug 20.76 20.49 20.18 6.12 6.12 20.40 20.76 20.35Sep 20.81 20.55 20.26 6.13 6.13 20.49 20.81 20.41Oct 20.94 20.75 20.51 6.17 6.16 20.74 20.94 20.60Nov 21.50 21.61 21.59 6.31 6.31 21.82 21.50 21.43Dec 20.37 19.90 19.44 6.02 6.02 19.65 20.37 19.78Avg 16.68 14.34 13.71 5.08 5.08 14.70 16.68 14.41

TY10 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 17.00 14.78 14.69 6.08 6.09 12.82 16.82 14.85Feb 14.61 11.21 11.08 5.38 5.39 8.36 14.47 11.40Mar 12.70 8.36 8.36 4.82 4.83 10.61 12.61 8.66Apr 12.84 8.56 8.56 4.86 4.87 10.77 12.74 8.85May 10.13 4.52 4.52 4.08 4.08 7.47 10.09 4.96Jun 11.51 6.57 6.57 4.48 4.48 9.15 11.44 6.94Jul 17.49 15.51 15.43 6.22 6.23 13.73 17.30 15.55Aug 20.94 20.68 20.65 7.23 7.24 20.19 20.68 20.53Sep 20.99 20.74 20.71 7.24 7.25 20.27 20.73 20.59Oct 20.86 20.94 20.91 7.28 7.29 20.52 20.86 20.79Nov 21.42 21.80 21.78 7.44 7.46 21.60 21.42 21.62Dec 20.55 20.08 20.04 7.11 7.12 19.44 20.29 19.96Avg 16.75 14.48 14.44 6.02 6.03 14.58 16.62 14.56

TY50 FWOP Alt2 Alt3 Alt4 Alt5 Alt6 Alt7 Alt8

Jan 17.24 15.56 14.75 10.02 10.02 16.32 17.04 15.64Feb 14.80 12.20 11.16 8.75 8.76 13.45 14.59 12.42Mar 12.86 9.52 9.44 7.74 7.74 11.30 12.64 9.86Apr 12.99 9.71 9.62 7.81 7.81 11.46 12.77 10.04May 10.24 5.90 5.90 6.38 6.38 8.27 10.00 6.40Jun 11.64 7.84 7.79 7.11 7.11 9.89 11.41 8.25Jul 17.73 16.25 15.48 10.27 10.28 16.90 17.54 16.30Aug 21.25 21.11 20.68 12.10 12.11 21.04 21.08 20.95Sep 21.30 21.17 20.74 12.13 12.14 21.09 21.12 21.01Oct 21.26 21.36 20.94 12.20 12.21 21.25 21.26 21.19Nov 21.85 22.17 21.81 12.50 12.51 21.94 21.85 21.96Dec 20.85 20.55 20.08 11.89 11.90 20.56 20.67 20.41Avg 17.00 15.28 14.87 9.91 9.91 16.12 16.83 15.37

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Table 16. FWOP and FWP average annual salinities for influence area G2,G3,G6.

* pumping alternatives

Measures to introduce freshwater into the Grand Bayou system would result in up to a 1,300 cfs

reduction in freshwater inputs to the Barataria Basin (Table 6a) and an average monthly

reduction of 516 cfs. Because the Davis Pond Freshwater Diversion Project operation schedule

is designed to introduce freshwater to maintain salinities at the designated 5 ppt isohaline across

the basin below Little Lake (Figure 17), the study team assumed that the operation of the Davis

Pond Diversion could compensate for the loss of GIWW freshwater inputs to that basin.

Consequently, an assessment of GIWW freshwater losses was not conducted within the Barataria

Basin.

Figure 17. Map depicting the location of the Davis Pond Diversion and the 5 ppt isohaline.

Alt2 Alt3 Alt4* Alt5* Alt6 Alt7 Alt8

(ppt) (ppt) (ppt) (ppt) (ppt) (ppt) (ppt)

FWOP TY1 8.3 8.3 8.3 8.3 8.3 8.3 8.3

FWP TY1 6.6 6.4 2.8 2.8 6.8 8.3 6.9

FWOP TY10 8.6 8.6 8.6 8.6 8.6 8.6 8.6

FWP TY10 6.9 6.9 3.2 3.2 6.9 8.3 6.8

FWOP TY50 10.0 10.0 10.0 10.0 10.0 10.0 10.0

FWP TY50 8.0 7.8 5.2 5.2 8.4 9.6 7.8

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The AAHU benefits presented in Table 5 were calculated without fisheries impacts (WVA

Variable 6 = 1.0 for all model runs) for the proposed Grand Pass plug (measure WP1), the

Robinson Canal plug (CP1), the Cutoff Canal plug (EP7), and the year-round closure of the HNC

Lock associated with the proposed HNC Lock Multi-purpose operations (measure CL1). Each of

those measures would correct significant hydrologic alterations on man-made canals which are

thought to have been significant causes of wetland degradation and loss. Additionally, the Grand

Pass plug would also serve as outfall management for WD2 and other Penchant Basin freshwater

introductions. The Robinson Canal plug would provide outfall management for Lake Boudreaux

Basin freshwater introduction measures, and the Cutoff Canal plug would provide outfall

management for Grand Bayou and St. Louis Canal freshwater introduction measures.

Theoretically, those outfall management features would increase the benefits associated with

their respective freshwater introduction measures. However, the preliminary application of

WVA Variable 6 (fish access variable) results in negative AAHUs for all alternatives, despite net

gains in wetland acres.

The decision not to apply the typical fisheries access impacts was justified in part by the

presence of other pathways for fisheries access. For example, channel cross-section data

provided by the Corps indicates that the structure on Grand Pass (measure WW2) would reduce

the available cross section of Grand Pass by 94%. However, Big Carencro Bayou, Blue

Hammock Bayou, Buckskin Bayou, and Bayou du Large would continue to provide unrestricted

water exchange and fisheries access to areas affected by WW2 (Figure 18).

Figure 18. Map delineating alternative fisheries routes for Measure WW2.

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Similarly, the Robinson Canal Plug (measure CP1) would eliminate all fisheries access to the

Lake Boudreaux Basin through Robinson Canal (Figure 19). The ARTM project would not

affect fisheries access to the Lake Boudreaux Basin via Boudreaux Canal. ARTM-related

increased closure duration of the HNC Lock would affect fisheries access to upper Bayou Grand

Caillou and thereby to Bayou Dulac

Figure 19. Map delineating alternative fish access routes for Measure CP1.

Comparison of FWOP and FWP (ARTM) total cross channel cross-section may provide a

measure of fisheries exchange reduction. However, natural and artificial variations in waterway

cross section may make such an analysis questionable depending on where cross section

measurements are taken. Concurrent FWOP discharge measurements made by the USGS

(Figure 20) indicate that Robinson canal provides 44 to 45% of the total Lake Boudreaux Basin

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water exchange. Provided that installation of that plug results in no compensatory flow

increases, measure CP1 might thereby reduce fisheries access to the basin by 44 to 46%.

Figure 20. Lake Boudreaux Basin tidal pass discharges.

Lake Boudreaux Basin Tidal Passes

May 20-21, 1999

-5,000

-4,000

-3,000

-2,000

-1,000

0

1,000

2,000

3,000

4,000

5,000

0 5 10 15 20 25 30 35

Hours

Discharge (cfs)

Robinson Canal

Bayou Dulac

Boudreaux Canal

Because ARTM-related HNC Lock closures would impact fisheries access via Bayou Dulac, a

further reduction in fisheries access would likely occur. Those impacts, however, affect access

provided by man-made canals and it could be argued that they would restore a more natural level

of fisheries access.

FWOP water exchange through Bayou Dulac would be affected by the HNC Lock and the Bayou

Grand Caillou Floodgate (both are features of the Morganza to the Gulf Hurricane Protection

Project). Those Morganza affects, considered as part of the FWOP ARTM condition, have not

yet been fully determined as design work for those features is not yet complete, and operation of

those Morganza features has not been determined.

According to Corps channel cross-section data, the Cutoff Canal Structure (EP7), would reduce

the existing cross section of the Cutoff Canal by 96%. This value may be high because the

structure is located in an unusually deep portion of the Cutoff Canal. Grand Bayou Blue also

provides a natural alternative fisheries access route to the area impacted by EP7 (Figure 21).

When the Grand Bayou Blue cross-section of 2,426 square feet (roughly at the same latitude as

EP7) is considered, the total FWP cross section provided by both channels is reduced 52%, from

a FWOP value of 5,301 square feet, to a FWP Alt2 value of 2,546 square feet. Given the

degraded condition of marshes in the Grand Bayou Blue area, there are also many other un674
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named small alternative routes for fisheries access into the area that would further reduce the

fisheries access impacts of measure EP7.

Figure 21. Map delineating alternative fisheries access routes for Measure EP7.

Further assessment work is needed to address this apparent conflict between fisheries access and

restoration of canal-related hydrologic impacts. That work should include staff from the

National Marine Fisheries Service and other interested natural resource agencies.

The results discussed above are for the low SLR scenario. Benefits under the medium SLR

scenario were prepared when initial indications suggested that Alt3 was the TSP (Table 17).

Time did not allow for the actual TSP (Alt2), to be evaluated under the medium SLR scenario.

However, the degree of benefit reduction should be very similar to the 66% reduction in Alt3

TY50 AAHUs.

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Table 17. Comparison of TY50 Alt3 benefits under low and medium SLR.

In summary, the TSPs freshwater introduction measures would restore and re-establish natural

processes which promote a more self-sustaining ecosystem. Under the low SLR scenario, the

TSP would provide an additional 3,220 AAHUs (Table 5), and would reduce wetland loss rates,

saving over 9,600 acres of marsh by the end of the 50-year project life (Table 18). Given the

FWOP loss of over 101,000 acres by TY50, the TSP (Alt2) would reduce this loss by only 10%.

Changes in future habitat types can not be predicted using the methods available, however, the

proposed freshwater introduction measures may temporarily halt or reverse the FWOP shift

toward more brackish habitat types in the central and eastern study area. Alt2 benefits also

include increased habitat diversity (primarily in central and eastern portions of the study area),

greater abundance of submerged aquatic vegetation, and a greater proportion of shallow open

water habitats.

Table 18. Summary of FWOP and FWP study area acreages by target year.

FWOP Alt2

FWOP Acres Net FWP

(acres) Lost (acres) (acres)

TY0 560,321 0 0 560,321

TY1 557,901 -2,419 -214 557,687

TY10 534,330 -25,991 1,832 536,162

TY50 458,894 -101,427 9,655 468,549

Alt3 Alt3 Alt3 Alt3

low SLR med SLR low SLR med SLR

Diversion Influence Area (AAHUs) (AAHUs) (acres) (acres)

E2-E4 -2 -1 0 0

F2 -13 0 0 0

A6,A7,L.Pagie 2,154 781 8,018 0

B6, B7 872 408 2,833 2,090

Bayou Dulac -266 5 -252 0

C2-C7 394 145 855 0

C9 263 52 602 0

G1-G5 -216 -169 -253 -222

G2,G3,G6 (G7) 1,203 170 4,880 0

Palm-Creole 0 0 0 0

C11-C14 -921 -198 -6,508 0

SUBTOTAL 3,467 1,192 10,175 1,868

Diversion Independent Measures

WD2 -165 -165 -319.0 -164.7

WO2 12 67 375.0 67.4

CD1 -1 -1 -3.4 -0.6

CD3 -3 -2 -7.6 -2.4

CD7 -1 3 -6.4 2.9

CT1,6,7,8 19 12 59.0 12.1

EM3 2 23 51.2 23.0

ED5 -5 -4 -14.1 -4.2

SUBTOTAL -142 -67 134.7 -66.6

TOTAL 3,325 1,126 10,310 1,801

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Although the TSP provides much needed wetland restoration benefits, those benefits will not be

of sufficient magnitude to prevent all the wetland losses in the central and eastern portions of the

study area. While the Service supports implementation of a restoration project within the study

area, project cost-constraints have precluded evaluation of larger measures/projects that might

provide significantly greater benefits. To significantly increase area self-sustainability, those

measures/projects must include larger volumes of freshwater inputs and those inputs must

contain reasonable quantities of suspended sediments to counter effects of subsidence and sea

level rise. Ideally, such efforts should also integrate hurricane protection planning with coastal

wetland restoration so that one does not preclude the other. The Service encourages such

planning efforts and is willing to assist in such efforts however possible.

FISH AND WILDLIFE CONSERVATION AND MITIGATION MEASURES

Plan formulation and evaluation shortcomings

Given the very high study area wetland loss rates and the hydrologic complexity of the study

area, effective and/or large-scale wetland restoration efforts will likely be costly. Evaluation of

such large-scale and more costly restoration opportunities were precluded by project cost limits

established in the authorizing legislation (Water Resources Development Act 2007, Title VII,

Section 7006). Additionally, because of the time required to complete hydraulic modeling runs

and conduct the subsequent analyses, the modeling of numerous alternatives was also precluded

by the compressed study schedule. These constraints may have precluded development and

analysis of more costly and potentially more effective alternatives, such as larger water control

structures in the Avoca Island Cutoff Levee capable of introducing greater volumes of

Atchafalaya River water into the Bayou Chene/GIWW conduit.

Although the proposed alternative plans were developed to protect and restore rapidly degrading

coastal wetlands, some of the proposed measures would result in direct wetland impacts

associated with the dredging of new channels and/or the enlargement of existing channels (Table

19).

Table 19. Summary of construction impacts by habitat type. Swamp/Wetland

Forest

Fresh

Marsh

Intermediate

Marsh

Brackish

Marsh

Saline

Marsh

Measure

Total

Feature Id Feature Name (acres) (acres) (acres) (acres) (acres) (acres)

ED2 St. Louis Canal enlargement 98.8 114.0 40.5 253.3

ED3 Upper Grand Bayou Canal enlargement 20.6 120.0 46.8 187.4

ED6 Grand Bayou East Branch enlargement 74.0 74.0

ED7 Lower Grand Bayou Canal enlargement 20.9 20.9

CD1 Bayou Provost enlargement 2.6 5.4 8.0

CD3 East Falgout Canal extension 8.5 8.5

CD7 Bayou Pelton enlargement* 1.5 7.7 9.2

CD6 Lake Boudreaux Water Conveyence Channel* 2.7 48.0 50.7

CLV1 North Forced Drainage Levee 4.9 4.9

CLV2 South Forced Drainage Levee 4.6 4.6

WD2 Relic Carencro Bayou enlargement 319.1 319.1

TOTAL 126.2 326.8 305.4 182.2 0.0 940.6

* Impact estimates from CWPPRA Lake Boudreaux Basin Freshwater Introduction Project (TE-32a)

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Due to the complexity of this project and the compressed study schedule, there was no

opportunity to evaluate alternative sizing of proposed channel construction/enlargement

measures to optimize channel size and thereby ensure that unnecessary wetland impacts were

avoided. Because model-predicted salinities demonstrate that proposed Grand Bayou channel

enlargement measures would result in higher average salinities during the fall months (Table 15),

a size/design analysis of the proposed St. Louis Canal and Grand Bayou Canal enlargement

measures would also provide an opportunity to determine if other channel sizes or designs might

reduce this undesired effect and result in a design with comparable benefits but less impacts.

The only enlargement design of Grand Bayou Canal (in the eastern study area) was the design

determined to be most effective under the CWPPRA Central and East Terrebonne Freshwater

Delivery Project. Although that design was based on a hydraulic modeling analysis of various

sizes and designs (branching versus straight channels), modeling flaws known to have occurred

may have invalidated the results of that modeling effort. Correction of those modeling flaws and

modeling re-analysis would be the only way to indentify the most effective Grand Bayou

enlargement alternative. Because of the compressed study schedule, this re-analysis could not be

done. Instead, the ARTM project had to rely on the faulty CWPPRA project modeling.

A number of known errors and problems affect the ability to determine the benefits/impacts of

the proposed HNC Lock Multi-Purpose Operations Project. Those issues include the omission of

the Morganza Projects Falgout Canal structures, model mesh detail below the HNC Lock,

unexplained increased salinities above the HNC Lock, potential impacts associated with the

HNC Lock sluice gate operations, unaccounted for freshwater inputs, and several errors

regarding application of the SAND2 model. These issues should be addressed in concert with

the National Marine Fisheries Service, the Louisiana Department of Wildlife and Fisheries, and

other interested natural resource agencies.

The study schedule also precluded an opportunity to assess the effectiveness of measures to

improve delivery of fresh water to central and eastern portions of the study area by enlarging

constricted segments of the GIWW. If those measures were found ineffective in increasing

freshwater inputs to desired locations, then the associated construction expense may be

unnecessary and may result in a project with reduced cost effectiveness. Similarly, the

compressed study schedule also precluded opportunities to assess benefits of individual outfall

management measures or small groups of outfall management measures. Because these

assessments could not be undertaken, the selected plan may not be as cost-effective as possible.

More significantly, the TSP includes 4 plugs on man-made channels (one being the HNC Lock).

Although those channels have resulted in major hydrology impacts and are suspected of having

increased loss rates of affected wetlands, the proposed plugs would reduce canal-enhanced

fisheries access. Preliminary indications are that use of the standard assessment methods for

evaluating those fisheries access impacts would result in negative AAHUs for project

alternatives containing those plugs. The Service believes that it would be inappropriate to assess

full fisheries impacts to those features because they are located on man-made canals and because

those features would correct canal-induced adverse hydrologic alterations. Hence, the Service

has not proceeded with the standard fisheries access impact assessments.

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Methodology shortcomings

The potential fisheries access impacts associated with the Grand Pass plug, the Robinson Canal

plug, the Cutoff Canal plug, and the HNC Lock MPO, are not included in the current analysis.

Although those plugs would address harmful canal-related wetland impacts, they would also

reduce canal-enhanced fisheries access and would therefore result in overall AAHU impacts,

according to the standard methodology for assessing such impacts. Because the standard

fisheries impact assessments do not consider the fisheries access increases associated with the

canal construction, that assessment approach can not only subordinate coastal wetland restoration

to fisheries access, but it can also serve to discourage wetland restoration and maintain the status

quo. Accordingly, the Service believes that it is inappropriate to assign full fisheries access

impacts in cases where natural waterways and/or other canals would remain open to provide

access more typical of the natural system.

The Service will proceed with a potentially modified assessment of fisheries impacts in

consultation with the National Marine Fisheries Service (NMFS), the Louisiana Department of

Wildlife and Fisheries (LDWF), and other interested natural resource agencies. Possible

methodology modifications would likely include the consideration of compensatory water

exchange increases at other locations due to plug installation. Other modification may also be

considered.

Several errors occurred in the reverse application of the SAND2 model for determining

impacts of project-related freshwater input reductions. Correction of those errors might reduce

the negative impacts of freshwater input reductions. Late in the study, it was also discovered that

the SAND2 model may begin providing unrealistic freshwater introduction related net wetland

acreage gains in areas where marsh loss rates decrease dramatically over time. This

methodology error could not be fully corrected prior to preparation of project reports.

Benefits associated with project-related salinity change would normally be captured through use

of the WVA marsh models. However, in many cases, both the reduced FWP average salinities

and FWOP salinities remained within the broad optimal ranges for the particular marsh model

used. As a result, benefits for those salinity reductions were rarely if ever captured in the benefit

assessments. Recently developed models are now available which would predict wetland

acreage benefits based on salinity-related change using salinity vs primary productivity

relationships. Use of those models would allow the project-related salinity change benefits to be

captured. However, because those models are not yet certified, Corps policy will not allow them

to be used. Because few Corps-approved benefits assessment models/tools are currently

available, an undetermined amount of project benefits may be unquantified.

FUTURE SERVICE INVOLVEMENT

Because of the issues discussed above, vital information needed to conduct a proper and

reasonable assessment of alternatives and project impacts is unavailable. Consequently, further

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evaluations are needed. Due to the extent and complexity of remaining benefits assessment

work, extensive funding will be needed by the Service to conduct the needed work and

participate throughout future detailed planning and post-authorization engineering studies, and to

facilitate fulfillment of our reporting responsibilities under Section 2(b) of the Fish and Wildlife

Coordination Act. Accordingly, the Service plans to work closely with the Corps and the State

of Louisiana to prepare detailed funding estimates to support our continued involvement in this

project.

Under provisions of Section 7 of the Endangered Species Act of 1973, as amended, the Service

will also assist the Corps to ensure that they will not jeopardize the continued existence of

threatened and endangered species, or adversely modify any designated critical habitat. The

required consultations will build on the programmatic consultation contained in the

Programmatic Environmental Impact Statement for the LCA study.

SUMMARY AND SERVICE POSITION

Having worked very closely with the Corps throughout the formulation and evaluation of project

alternatives, we are very familiar with the studys substantial cost and schedule-related

constraints, as well as the benefits assessment errors discussed previously. Unfortunately, those

constraints have precluded the consideration of truly large-scale ecosystem restoration efforts

that are needed in the study area, perhaps more so than anywhere else along the Louisiana coast,

due to the hydrologic complexity of the area and its rapid wetland loss rate. Consequently, the

TSP should be viewed as an array of short-term measures, and that the assessment of long-term

and more effective alternatives remain to be undertaken.

Study schedule constraints have also precluded opportunities for iterative project refinement

based on earlier analysis. Because such project refinement could not be undertaken, the TSP

may result in unnecessary wetland impacts and reduced project cost effectiveness. The study

schedule constraints have also precluded correction of many of the known planning and

evaluation errors. However, some of those errors and issues are likely of lesser magnitude than

those resulting from the significant uncertainties associated with hydrologic modeling

inaccuracies and those of the associated benefits assessment methodologies. When the study

schedule precludes correction of known errors and assessment deficiencies, proceeding with

authorization and construction of projects is far from ideal. Yet, the need to take quick action to

stem rapid degradation and wetland loss may to some extent counterbalance the reasonable

expectation to achieve higher-quality planning and benefits assessments. Accordingly, the

Service supports implementation of the TSP, provided that the following additional assessment

work is continued during the remaining planning phase and completed during the

preconstruction, engineering, and design phase, to address outstanding major issues that could

result in substantial improvements and/or modifications to the selected plan. Failure to make

significant progress on the following recommendations would result in quality of impact/benefits

disclosure significantly less than that typically associated with feasibility-level planning and

assessment. Furthermore, because of the schedule-driven decision to accept errors, the Service is

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unable to entirely fulfill our Coordination Act responsibilities until the following major issues

are addressed:

1. The Corps shall pursue additional hydrologic modeling and benefit analysis of various

sized and designed enlargements of Grand Bayou Canal/Bayou LEau Bleu (measures

ED3, ED5, ED6, and ED7) to avoid unnecessary construction impacts and unnecessary

canal-induced saltwater intrusion impacts. That work should also include efforts to

assess project-related effects of reduced freshwater inflows to the Barataria Basin. The

Service and other interested natural resource agencies should be involved in this effort.

2. The Corps shall pursue additional hydrologic modeling and benefits analysis of various

sized and designed enlargements of St. Louis Canal (measure ED2) to avoid unnecessary

construction impacts and unnecessary canal-induced saltwater intrusion impacts.

Following those additional assessments (qualitatively or quantitatively), the cost

effectiveness of the Grand Bayou and St. Louis Canal enlargements should be ranked to

determine whether they both should be included in the TSP. The Service and other

interested natural resource agencies should be involved in this effort.

3. The Corps shall pursue additional hydrologic modeling and assessment of benefits and

impacts resulting from the HNC Lock Multi-purpose Operations Project to more

accurately assess anticipated benefits and impacts, especially that of impacts below the

Lock. This revised assessment of HNC Lock Multi-purpose Operations should include

the following:

a) Assess whether the existing model grid in the area south of the HNC Lock is

adequate to simulate lock-related hydrology there. If not, revisions to the model

grid should be undertaken.

b) Less than half of the water rerouted from the lower HNC via HNC Locks MPO is

currently accounted for elsewhere. Model results should be re-examined to find

the unaccounted for flow and determine a benefit for that flow.

c) The Morganza Projects Falgout Canal water control structures should be

included in the hydraulic model.

d) Review and correct if necessary, the Lake Boudreaux water mixing parameters

within the hydraulic model to validate/correct the predicted trends of FWP

increasing salinities north of the HNC Lock.

e) The FWP increasing salinity trend north of the HNC Lock may be related to

operation of the HNC Lock sluice gates. The size and operation of those sluice

gates should be described.

f) If those sluice gates are determined to be the cause of increased FWP salinities

north of the HNC Lock, the Service recommends that alternative sluice gate

operations should be assessed to avoid FWP salinity increases. The Service and

other interested natural resource agencies should be involved in this effort.

4. The Corps shall avoid adverse impacts to bald eagle nesting locations and wading bird

colonies through careful design of project features and timing of construction. A

qualified biologist should inspect the proposed work site for the presence of

undocumented wading bird nesting colonies and bald eagles during the nesting season

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51

(i.e., February 16 through October 31 for wading bird nesting colonies, and October

through mid-May for bald eagles).

5. Unless needed for construction of spoil banks, dredged material should be used to create

marsh in strategic locations (to the greatest degree possible). The Service and other

interested natural resource agencies should be involved in this effort.

6. Operation plans for project water control structures should be developed in coordination

with the Service and other interested natural resource agencies. Those operation plans

should incorporate flexibility to respond to changing environmental conditions.

7. The Corps shall establish and continue coordination with the Louisiana Department of

Wildlife and Fisheries (225/765-2360) regarding the planning of project features that will

impact the Pointe-aux-Chenes Wildlife Management Area and State owned and managed

oyster seed grounds. Coordination shall also be re-established prior to construction and

any subsequent maintenance.

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LITERATURE CITED

Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands

Conservation and Restoration Authority. 1998. Coast 2050: Toward a Sustainable

Coastal Louisiana. 161 pp.

Nyman, J.A., DeLaune, R.D., and W.H. Patrick, Jr. Relationship between Vegetation and Soil

Formation in a Rapidly Submerging Coastal Marsh. Marine Ecology Progress Series.

Vol. 96: 269-279, 1993.

Swarzenski, C.M. 2003. Surface-water hydrology of the Gulf Intracoastal Waterway in SouthCentral Louisiana, 1996-1999. U.S. Geological Survey Professional Paper 1672;

prepared in cooperation with the U.S. Army Corps of Engineers, New Orleans District.

Turner, R.E. 1977. Intertidal vegetation and commercial yields of penaeid shrimp.

Trans. Am. Fish. Soc. 106:411-416.

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APPENDIX A

Letters from the

National Marine Fisheries Service

and the

Louisiana Department of Wildlife and Fisheries

Providing comments on the U.S. Fish and Wildlife Services

May 2010 Draft Fish and Wildlife Coordination Act Report

684
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685
A-3

686
A-4

687
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APPENDIX C

NOAA FISHERIES SERVICE COORDINATION

LETTER

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Volume VI

APPENDIX C:

NOAA Fisheries Service Coordination Letter

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693

APPENDIX D

404(b)(1) Evaluation

695
Volume III  Convey Atchafalaya Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Operation Lock  Appendix D  404(b)(1) Evaluation

D-1

SECTION 404(b)(1) EVALUATION

LOUISIANA COASTAL AREA - ECOSYSTEM RESTORATION PROJECT

Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock

I. INTRODUCTION

A.

The Louisiana Coastal Area  Convey Atchafalaya River Water to Northern Terrebonne

Marshes and Multipurpose Operation of Houma Navigation Lock project (LCA-ARTM)

project area comprises approximately 1,100 square miles (~700,000 acres) in Southern

Louisiana. LCA-ARTM fits into the Louisiana Coastal Area Ecosystem Restoration

Study Area, which has been identified as the Louisiana coastal area from Mississippi to

Texas.

Purpose and General Description.

The purpose of the proposed action is to reverse the current trend of degradation of the

Terrebonne Marshes, so as to contribute towards achieving and sustaining a coastal

ecosystem that can support and protect the environment, economy, and culture of

Southern Louisiana and thus the Nation. The objective of the study is to provide

additional freshwater, nutrients, and fine sediment to the area. The introduction of

additional freshwater would facilitate organic sediment deposition, improve biological

productivity, and prevent further deterioration of the marshes. Specific project objectives

include, but are not limited to: preventing, reducing and/or reversing future wetland loss;

achieving and maintaining characteristics of sustainable marsh hydrology; reducing

salinity levels in project area; increasing sediment and nutrient load to surrounding

wetlands; increasing residence time of fresh water; and sustaining productive fish and

wildlife habitat.

B.

The LCA-ARTM Project Area (Figure 1) is situated in Southern Louisiana in the vicinity

of the City of Houma and Terrebonne Parish. The overall project is bound to the west by

the Lower Atchafalaya River and to the east by the Bayou Lafourche ridge. The project

area is bound to the north by the Bayou Black ridge, from the Lower Atchafalaya River

to the City of Houma, and by the Gulf Intracoastal Waterway (GIWW) from the City of

Houma to the Bayou Lafourche ridge. The southern boundary of the project was based

on a delineation conducted in 2007 of coastal Louisiana vegetation types. The boundary

roughly follows the transition between saline and brackish marsh types identified by

Sasser et al. (2008). The project area contains a complex of habitat types, including

natural levees, lakes, swamps, marshes, and bayous formed from sediments of abandoned

Mississippi River deltas. Due to the magnitude of the project area, the entire LCAARTM study was divided into three subunits. The three subunit areas are referred to

Location.

as West-Bayou Penchant Area, Central-Lake Boudreaux Area, and East-Grand Bayou

Area.

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Figure 1 LCA-ARTM Project Area.

The West  Bayou Penchant Area is the largest of the three subunits identified by the

LCA-ARTM PDT, measuring approximately 680 square miles in size. The area envelops

sections of the GIWW that connect Morgan City, Louisiana to Houma, Louisiana. The

name of the subunit lends itself to the presence of the Penchant Basin, which is one of the

larger, more signature features within the subunit. The boundaries of the subunit can be

characterized as the following: the northern limits of the West  Bayou Penchant Area

subunit follow the northern edge of Lake Palourde and extend eastward down the Bayou

Black Ridge. The eastern limits are mostly bound by Bayou du Large, and the western

limits trace the Lower Atchafalaya River south of Morgan City, then cut eastward and

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line the edge of Four League Bay. Major freshwater delivery systems within the West 

Bayou Penchant Area subunit consist of the Atchafalaya River, Bayou Shaffer, Bayou

Boeuf, GIWW, Bayou Chene, Bayou Penchant, Bayou Copasaw, and Minors Canal.

Other significant features located within the study subunit include portions of the

proposed Morganza to the Gulf levee. The ecosystems within the West  Bayou

Penchant Area can be characterized as mostly forested swamps between the GIWW and

Bayou Black, floating freshwater marsh systems throughout the Penchant Basin, and

intermediate marsh systems starting in the vicinity of Lake de Cade. Brackish marsh

systems are also within the subunit, south of the intermediate zone.

The Central  Lake Boudreaux Area subunit, measuring approximately 210 square miles,

extends south of the GIWW at Houma, Louisiana and envelops the Houma Navigation

Canal. The limits of the subunit adjoin the West  Bayou Penchant Area subunit at

Bayou du Large. The eastern limit of the Central  Lake Boudreaux Area subunit

consists of Bayou Terrebonne. Major freshwater delivery features within the Central 

Lake Boudreaux Area include the GIWW, Houma Navigation Canal, Bayou du Large,

Bayou Grand Caillou, Bayou Petit Caillou, and Bayou Terrebonne. Other significant

features located within the study subunit include Lake Boudreaux, Lake Quitman, and the

proposed Houma Navigation Canal lock complex and Morganza to the Gulf levee. The

landcover within the Central  Lake Boudreaux Area can be characterized as mostly

urban and agriculture along Bayou Du Large, Bayou Grand Caillou, Bayou Petit Caillou,

and Bayou Terrebonne. Between the bayous, the stratification of ecosystems shifts from

forested swamps in the north, to freshwater marsh systems, to intermediated systems.

Brackish marshes are found around and south of Lake Boudreaux.

The East  Grand Bayou Area Subunit is located south of Larose, Louisiana and

measures approximately 185 square miles. The LCA-ARTM PDT identified the northern

limits of this study unit to be bound by the GIWW, the western limits to be bound by

Bayou Terrebonne, and the eastern limits to be bound by the Bayou Lafourche ridge.

The name of the subunit lends itself to the presence of the Grand Bayou Basin, which is

one of the larger, more signature features within the subunit. Major freshwater delivery

features within the East  Grand Bayou Area include the GIWW, Bayou Pointe au Chien,

Grand Bayou, Bayou Blue, Grand Bayou Blue, and Cutoff Canal. Other significant

features that are present within the study area include St. Louis Canal and portions of the

Pointe au Chien Wildlife Management Area.

C.

Title VII of the Water Resources Development Act (WRDA) 2007 authorizes the

Louisiana Coastal Area (LCA) ecosystem restoration program. Included within that

authority are requirements for comprehensive coastal restoration planning, program

governance, a Science and Technology Program, a program for the beneficial use of

dredged material, feasibility studies for restoration plans, project modification

investigations, and restoration project construction, in addition to other program

elements. This authorization was recommended by the Chief of Engineers Report, dated

January 31, 2005.

Authority.

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Under the 2007 WRDA Section 7006, the LCA program has authority for feasibilitylevel reports of six near-term critical restoration features. The excerpt below from

WRDA outlines the project authority for this report for the LCA-ARTM:

SEC. 7003. LOUISIANA COASTAL AREA.

(a) IN GENERAL.-The Secretary may carry out a program for ecosystem

restoration, Louisiana Coastal Area, Louisiana, substantially in accordance with

the report of the Chief of Engineers, dated January 31, 2005.

SEC. 7006. CONSTRUCTION.

(3) PROJECTS SUBJECT TO REPORTS. (A) FEASIBILITY

REPORTS.Not later than December 31, 2008,the Secretary shall

submit to Congress feasibility reports on the following projects

referred to in the restoration plan:

(i) Multipurpose Operation of Houma Navigation Lock at a total

cost of $18,100,000.

(ii) Terrebonne Basin Barrier Shoreline Restoration at a total cost

of $124,600,000.

(iii) Small Diversion at Convent/Blind River at a Total cost of

$88,000,000

(iv) Amite River Diversion Canal Modification at a total cost of

$5,600,000.

(v) Medium Diversion at Whites Ditch at a total cost of

$86,100,000.

(vi) Convey Atchafalaya River Water to Northern Terrebonne

Marshes at a total cost of $221,200,000.

(B) CONSTRUCTION.The Secretary may carry out the projects

under subparagraph (A) substantially in accordance with the

plans and subject to the conditions, recommended in a final report

of the Chief of Engineers if a favorable report of the Chief is

completed by not later than December 31, 2010.

(4) CONSTRUCTION.No appropriations shall be made to construct

any project under this subsection if the report under paragraph (2) or

paragraph (3), as the case may be, has not been approved by

resolutions adopted by the Committee.

The integrated feasibility study and environmental impact statement (EIS)

conducted for the LCA-ARTM fulfills the reporting requirement to Congress

under Section 7006(e)(3) which directs the Secretary of the Army to submit

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feasibility reports on the six projects included in the referenced section by

December 31, 2008. The authority also provides approval to implement the

projects provided a favorable Chief of Engineers Report is completed no later

than December 31, 2010.

D.

(1) General Characteristics of Material

General Description of Dredged and Fill Material.

The interagency team composed of the Corps, USFWS, NOAA, and the State of

Louisiana has Recommended a plan, which meets the study objectives. The

selected plan referred to as the RP reasonably maximizes ecosystem restoration

benefits compared to costs. The RP redistributes existing freshwater to benefit

Terrebonne marshes using a variety of measures. The following measures to

restrict, increase, and control water are proposed for each of the three subunits. In

the West  Bayou Penchant Area, dredging, a sediment plug, and a weir will be

utilized. In the Central  Lake Boudreaux Area, culverts, levees, dredging, marsh

terraces and berms, sediment plugs, modified operation of the future HNC

(Houma Navigation Canal) lock complex, and a large sluice gated box culvert are

proposed. In the East  Grand Bayou Area, culverts, dredging, gaps in canal spoil

banks, marsh berms, sediment plugs, and removal of a weir and soil plug are

proposed. The fifty-six construction features associated with the RP are

summarized below and are summarized by activity type.

(a) Deepening and widening of existing channels and creation of new conveyance

channels will be performed as part of this project (see Appendix R drawing C339 for typical sections of channel deepening or widening and R-102 and 103

for the new conveyance channel). Unless otherwise specified, an adjacent berm

will be constructed to contain dredge spoil. The dredged channels will be

constructed using one of the available dredge types in the area (i.e., cutter head).

Type A Dredged Channels, will be cut 5 feet or more away from the existing

bankline to prevent sloughing of the bankline. Unless otherwise specified, it is

assumed that all spoil material will be placed in an adjacent spoil area that is

constructed by building berms from in-situ material. If it is determined that the

dredge spoil can be used beneficially in other areas, the material will be used for

swamp and marsh nourishment. Dredge material will consist of excavated insitu material which is characterized as follows: surface and shallow subsurface

deposits found in swamps and marshes, canals, lakes, and bayous.

(b) Plugs will be constructed with a close-graded limestone aggregate obtained

from a quarried source. The aggregate will be placed to an elevation 2 feet

above the water surface. The plug will be tied-in with 1 vertical to 4 horizontal

slope extending to the existing ground (see Appendix R drawing C-340 for a

typical section). The aggregate will be placed with a track-hoe bucket and will

most likely be brought to the site via a barge or other floating vessel. It is

assumed that access to the sites is available or will be made available through

flotation channels.

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(c) Precast and cast-in-place concrete culverts will be placed to convey water from

one area to the other. Depending upon the location, there may be multiple

barrels and/or a flap gate. Those areas proposed for culverts will be excavated

to 2 feet below the flow line. The trench will be filled with 2 foot aggregate

bedding material and backfilled around the pipe. Culverts will be installed

through roadways, natural ridges, and dredged material embankments locally

known as spoil banks. It is assumed that access to the sites is available or will

be made available through flotation channels.

(d) Existing dredge spoil banks will be excavated to allow water conveyance and are

referred to on the drawings as Spoil Gaps (see Appendix R drawing C-342 for

details). The gaps will be excavated 50 feet long and will be excavated with

track-hoes and sloped back to existing ground. The excavated material will be

either hauled off by the contractor or placed adjacent to the gap. All exposed

ground above the water surface will be seeded to reduce erosion. It is assumed

that access to the sites will be made available through flotation channels.

(e) Removal of existing structures will occur using equipment containing a bucket

or a grapple. The material will be removed off site and disposed at the

contractors discretion. It is assumed that access to the sites is available or will

be made available through flotation channels. Two features will be removed

from canals within the East Grand Bayou Area. These features include a rock

weir and an existing soil plug.

(f) Diversion structure. This Central Diversion Structure (CS1) involves

constructing six 10' x 10' gated box culverts on Bayou Butler under Highway

57. The structure will increase fresh water movement from the HNC to Bayou

Grand Caillou/Lake Boudreaux.

(g) Levees listed on project plans as features CLV1 and CLV2 measure 5,173 linear

feet and 1,760 linear feet and will be constructed and function as forced

drainage levees. The levees will be created out of soil and will directly impact

23 acres of swamp through conversion to upland habitat. The proposed levees

would prevent potential flooding from proposed increases in flows to Lake

Boudreaux. Several project features (CC3, CC 5-15, [CD1-2, 6, 7], CLV1,

CLV2, and CP2) together will work in conjunction with the Central Diversion

Structure to deliver and retain fresh water and to prevent greater saltwater

intrusion into Lake Boudreaux.

(h) A Weir will be constructed of limestone riprap and will be placed across the

channel approximately 10 feet below the water surface. Side slopes will be 1

vertical to 5 horizontal as shown on drawing C-339 (Appendix R).

(i) Terracing berms will be constructed by excavating adjacent in-situ material and

piling the material until the berm is 2 feet above the water surface. The Terraces

will consist of a series of 10 foot wide parallel berms positioned approximately

90 degrees to the direction of surge (See Appendix R drawings C-341 for

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details). Borrow trenches will be located a minimum of 25 feet away to prevent

sloughing. The exposed ground above the water surface will be vegetated to

reduce erosion. It is assumed that access to the sites is available or will be made

available through flotation channels.

(j) Marsh berms will be created by borrowing adjacent in-situ material at least 25

feet from the berm toe. The material will be piled until the berm is at an

elevation of +2.5 feet. All berms are expected to contain a 30 foot wide top

width and any exposed ground above the water surface will be seeded for

erosion protection. It is assumed that access to the berm sites are available or

will be made available through flotation channels. Material for the berm will

be obtained by excavating in-situ material adjacent to the berm location. Spill

boxes will be placed in the berm to allow water to drain. The containment berm

construction will require constant monitoring to ensure no dredge material is

allowed to escape. The area within the containment berms will be filled with

dredge material up to an elevation of +2.5 feet to +3.0 feet. Booster pumps and

effluent pipes will run between the dredge borrow site and the marsh creation

areas. It is assumed from similar projects that the construction fill elevation of

the dredged material will settle over several years to an elevation of

approximately +1.0 feet to +1.5 feet. Once this elevation is achieved, marsh

vegetation can either be planted or will reestablish naturally. The containment

berms will be degraded to the adjacent dredge fill elevation after settling.

(2) Quantity of Material.

(a) Dredging will occur within all three subunits. Dredging activities within the east

subunit includes canal dredging to allow water movement from the GIWW to

Grand Bayou basin, as well as dredging within Grand Bayou to allow water

movement to East Grand Bayou marshes. The estimated quantity of dredged

material from the east subunit is 9.1 million cubic yards.

Dredging within the central subunit includes dredging within Bayou Provost, a

portion of Bayou Butler, and Falgout Canal to increase fresh water movement

from Houma Navigation Canal (HNC) to Bayou Grand Caillou/Lake Boudreaux.

A new water conveyance channel will be created to convey fresh water from

Bayou Pelton enlargement to north Lake Boudreaux marshes. Bayou Pelton will

also be dredged to enlarge the resource and increase fresh water movement from

the HNC to Bayou Grand Caillou/North Lake Boudreaux. A new secondary

channel along the GIWW at Hwy 24 bridges will also be created to increase

water volume moving past the GIWW constriction. An estimated 695,510 cubic

yards of material will be removed by the stated activities.

The western subunit includes dredging within a part of Carencro Bayou to create

a new canal for purposes of increasing delivery of fresh water from Bayou

Penchant to southeast Penchant Basin marshes. A portion of GIWW will also be

dredged to eliminate constriction in this waterway. An estimated 3.23 million

cubic yards of dredged material will be removed as part of the project.

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Unless otherwise specified, it is assumed that all spoil material will be placed in

adjacent spoil areas that are constructed by building berms from in-situ material.

If it is determined that the dredge spoil can be used beneficially in other areas,

the material will be used for swamp and marsh nourishment, particularly in the

vicinity of feature CD7 where approximately 92 acres of degraded marsh will be

nourished with dredge disposal material from Bayou Pelton.

(b) Close-graded aggregate will be used to create plugs within all subunits. The east

subunit will contain a plug and boat bay placed in Cutoff Canal on the north

bank of Bayou Pointe au Chien to retain fresh water in marshes to the north and

prevent saltwater intrusion from the south. Approximately 23,360 tons of

aggregate will be used to create the plug in the east subunit. The central subunit

has two plug features. One will occur at Robinson Canal and will retain fresh

water in Lake Boudreaux basin while preventing saltwater intrusion from Bayou

Petit Caillou. The second plug will be installed in a canal near Bayou Butler to

prevent short circuiting of fresh water through the north to south Gulf South

Pipeline canal. An estimated 15,000 tons of aggregate will be placed to create

the plugs. One plug is designed for the western subunit and will retain fresh

water in Bayou du Large and Lake Mechant. The feature will also prevent

saltwater intrusion. Approximately 7,500 tons of aggregate is required to create

the western plug.

(c) Precast and cast-in-place concrete culverts will be placed in strategic locations

in the eastern and central subunits (e.g. through roadways, ridges, or dredged

material embankments locally known as spoil banks). The primary purposes of

the culverts will be to improve freshwater distribution. Approximately 7,700

cubic yards of concrete will be placed in the eastern subunit, and 4,056 cubic

yards in the central subunit.

(d) Two spoil gaps will be created in existing canal spoil banks within the eastern

subunit. The spoil gaps will allow movement of fresh water from the unnamed

canal to marshes to the south/southwest and marshes to the east. Gaps will be

excavated 50 feet long with 1 vertical on 3 horizontal side slopes.

Approximately 20,500 cubic yards of material would be removed from the

existing spoil banks to create these openings.

(e) The rock weir and soil plug will be excavated from canals within the East Grand

Bayou subunit. The estimated removal quantity is 4,533 tons.

(f) The Central Diversion Structure (CS1) will be constructed under Highway 57

and will interface with Bayou Butler. The structure will consist of

approximately 35,400 square feet of precast concrete box culvert and an

additional 1,050 cubic yards of cast in place concrete.

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(g) Levees (CLV1 and CLV2) will result in the discharge of approximately 296,853

cubic yards of dredged material into 23 acres of swamp to create the elevated

surface to function as the forced drainage levee.

(h) A rock filled sheet pile weir with boat openings will be installed in the western

subunit and will constrict Grand Pass by 90 percent to minimize water exchange

between Bayou du Large and Caillou Lake. Approximately 9,400 tons of riprap

will be placed to facilitate construction of this feature.

(i) Terraces will be constructed within the central subunit within the Lake

Boudreaux area. The berms will be constructed by excavating adjacent in-situ

material and piling the material until the berm is 2 feet above the water surface.

The Terraces will consist of a grid of 10 wide berms perpendicular to surge

for purposes of retaining fresh water and preventing saltwater intrusion. The

associated excavation and discharge of dredged material is estimated at 1.1

million cubic yards.

(j) The eastern marsh creation requires constructing linear berms perpendicular to

tidal flow for purposes of slowing fresh water movement to the gulf and

preventing saltwater intrusion from the south in an effort to stabilize the

marshes in lower Grand Bayou basin. Soils for the berm creation will be

borrowed from open water areas within 25 feet from the proposed berm toe and

will be side cast to create an approximate 2.5 foot tall by 30 foot top width

berm. The estimated quantity of dredged material discharged to create the

eastern marsh berms is 711,187 cubic yards.

Marsh berms within the central subunit will be created in like fashion to those in

the eastern subunit. The berms will be placed perpendicular to flow and will

retain fresh water in central subunit Lake Boudreaux marshes as well as prevent

saltwater intrusion. A total of 821,000 cubic yards of material will be

excavated and placed to create the berms.

(3) Source of Material.

All excavated material, dredge material, and associated structure placement will

occur within the project area. These soils occur as ponded, frequently flooded,

and very frequently flooded, mucky and clayey, fluid soils that were formerly

deposited by the Mississippi River and are found in the Bayous, canals, open

water environments, marshes, and swamps that encompass the project area.

Riprap and crushed aggregate must be obtained from a quarry and brought in by

barge into the project area. Pre-cast concrete culverts will be obtained from a

manufacturer of the product. Concrete will be ordered from a concrete supplier to

construct all cast-in-place culverts.

E. Description of the Proposed Discharge Sites.

(1) Location and Size.

Figure 2 below provides an overview of the project features and their associated

position in the project area. The features are more specifically depicted in

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subsequent figures which follow Figure 2. The relative size of each feature is

discussed in this section as well.

Figure 2. Features Associated with the Proposed Action.

a) Deepening and widening of existing channels and creation of new conveyance

channels include activities within the eastern and central subunits. Project

measures in the eastern subunit include East Dredge Channel #5 (ED 5) which

is a new 1000-foot channel to connect the GIWW to Grand Bayou. East

Dredge Channel #3 (ED 3) is a 16,500-foot expansion of Grand Bayou to

deliver fresh water into the Grand Bayou Basin. A box culvert (EC 2) will

convey flow to the west through an existing levee along the alignment of the

existing Grand Bayou which will be dredged (ED 6) for a length of 16,800

feet to provide freshwater to the eastern Grand Bayou marshes.

Dredging within the central subunit includes dredging within Bayou Provost

(CD1) for 5,691 linear feet, and a portion of Bayou Butler (CD2) for 1,000

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linear feet. A new water conveyance channel will be dredged to convey fresh

water from Bayou Pelton to north Lake Boudreaux marshes. This feature is

identified as CD6 and contains a design length of 7,014 feet and 45-foot

width. Dredging activities will occur within Bayou Pelton (CD7) to enlarge

the resource (6,416 linear feet by 70 feet wide) and further assist in increasing

fresh water movement from HNC to Bayou Grand Caillou/North Lake

Boudreaux.

b) The east subunit will contain a plug and boat bay (EP7) that will be placed in

Cutoff Canal on the north bank of Bayou Pointe au Chien. The plug will

cover an approximate 5,000 square foot area.

The central subunit has two plug features. One plug identified as CP1will be

installed at Robinson Canal and will retain fresh water in Lake Boudreaux

basin while preventing saltwater intrusion from Bayou Petit Caillou. CP1 will

cover a 4,375 square foot area of Robinson Canal. The second plug (CP2)

will be installed in a canal near Bayou Butler to prevent short circuiting of

fresh water through the north to south Gulf South Pipeline canal. CP2 has a

design area of 1,500 square feet.

c) Culverts will be installed in the eastern and central subunits (see Table 1 for

structure name and dimensions and Figures 3 and 4 for locations).

Table 1. Culvert Designation and Dimension

ID1 Measure Name Description No. of Barrels Size/Width

(ft)

Length

(ft)

EC2 East Culvert #2 Box culvert 5 5x5 26

EC3 East Culvert #3 Flap gated box culverts w/variable crest

outfall 10 5x5 75

EC5 East Culvert #5 Bridge construction with Obermeyer gates

installed between the piers N/A 80 x 20 552

EC6 East Culvert #6 Flap gated box culverts 8 8x8 50

EC7 East Culvert #7 Flap gated box culverts 8 8x8 40

CC1 Central Culvert #1 Box Culvert under Highway 24 Bridge 6 10x10 115

CC2 Central Culvert #2 Box Culvert under Highway 24 Bridge 6 10x10 115

CC3 Central Culvert #3 Gated control structure 6 10x10 175

CC4 Central Culvert #4 Gated control structure 6 10x10 175

CC5 Central Culvert #5 Aluminum flap-gated culvert 1 4x4 48

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ID1 Measure Name Description No. of Barrels Size/Width

(ft)

Length

(ft)

CC63 Central Culvert #6 Aluminum flap-gated culvert 1 4x4 48

CC7 Central Culvert #7 Aluminum flap-gated culvert 1 4x4 48

CC8 Central Culvert #8 Aluminum flap-gated culvert 1 4x4 48

CC9 Central Culvert #9 Aluminum flap-gated culvert 1 4x4 40

CC103 Central Culvert #10 Aluminum flap-gated culvert 1 4x4 40

CC11 Central Culvert #11 Aluminum flap-gated culvert 1 4x4 40

CC12 Central Culvert #12 Aluminum flap-gated culvert 1 4x4 40

CC13 Central Culvert #13 Box culverts with sluice gates under Hwy

57 6 10x10 175

CC14 Central Culvert #14 Flap-gates w/ stop log bays 3 4x4 45

CC15 Central Culvert #15 Timber weir w/ boat openings N/A 68 N/A

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Figure 3 East Subunit Culvert Locations

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Figure 4. Central Subunit Culvert Locations

(d) Two spoil gaps (EG 1 and EG 2) will be excavated in the eastern subunit and

their specific locations are shown on Figure 5 below. The EG1 footprint is

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estimated at 1.7 acres and the EG2 gap is measured at 0.5 acres. The gaps

will be excavated -0.5 feet below the surrounding terrain.

Figure 5. Spoil Gaps and Structure Removal Locations

(e) Removal of a rock weir (EX 1) and a soil plug (EX 2) will increase water

movement through canals within East Grand Bayou. The removal area for

EX1 is 100 feet long by 50 feet wide. The soil plug EX2 covers an area

that is 130 feet long by 50 feet wide (see Figure 5 above for the removal

areas).

(f) The central diversion structure (CS1) is approximately 1-acre in size and

is located under Highway 57 and interfaces with Bayou Butler. See

Figure 6 below for the feature location.

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Figure 6 Central Diversion Structure Location

(g) Two levees will be constructed within the central subunit and are labeled

on Figure 7 below as CLV1 and CLV2. The levees measure 5,173 linear

feet and 1,760 linear feet respectively and will cover approximately 23

acres of swamp.

Figure 7 Levee Locations

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(h) A rock filled sheet pile weir with boat openings will be installed in the

western subunit and will constrict Grand Pass by 90 percent to minimize

water exchange between Bayou du Large and Caillou Lake. The design

dimensions for this structure are 100 feet long by 940 feet wide by 12 feet

deep.

(i) Terraces will be constructed within the central subunit within the Lake

Boudreaux area. See Figure 8 below for the measure name, location, and

size.

Figure 8 Central Terraces, Sizes and Locations.

(j) Marsh berms will be created within the eastern and central subunits. Marsh

berm (EM 1) will total 13,000 feet long by 30 feet wide. Further to the south,

EM3 will be created and will total 37,000 feet long by 30 feet wide. The

location of EM1 and EM3 are shown on Figure 3 above. Marsh berms (CM2,

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CM3, and CM4) will be created in the central subunit (depicted in Figure 4

above). CM2 contains a design dimension of 11,255 feet long by 30 feet

wide. CM3 is estimated at 8,975 feet long by 30 feet wide, and CM4 is

approximately 23,458 feet long by 30 feet wide.

(2) Type of Site.

(a) Deepening and widening of existing channels and creation of new

conveyance channels will occur within the bayous, canals, swamp/wetland

forests, fresh marshes, intermediate marshes, and brackish marshes.

(b) Plugs will be placed within bayous and canals, both of which consist of

open water environments.

(c) The culvert features will be placed within existing earthen levees,

excavated channels constructed through uplands, and under roadways.

Each of these structures will interface with aquatic resources to convey

flow from one waterway to another.

(d) Two spoil gaps will be created in existing canal spoil banks to allow

movement of fresh water from unnamed canals to adjacent marshes.

(e) Removal of a rock weir (EX1) and a soil plug (EX2) will occur in open

water canals situated in the Grand Bayou area.

(f) The Central Diversion Structure (CS1) will be installed under Highway 57

and the gated box culvert structure will interface with Bayou Butler.

(g) The levees within the central subunit will cover approximately 25.5 acres

with 23 acres of the area being labeled as swamp.

(h) The weir is proposed in an area known as Grand Pass which is situated

between Bayou du Large and Caillou Lake. Grand Pass consists of an

open water environment.

(i) Terracing Berms will be created within the shallow open waters of Lake

Boudreaux.

(j) Marsh Berms created within the eastern subunit (EM1 and EM3) will

primarily be created within shallow open waters of Grand Bayou. The

central subunit marsh berms (CM2 and CM3) are proposed within the

shallow open waters of Lake Boudreaux. Marsh berm (CM4) will traverse

open water habitats and brackish marshes situated to the west of Bayou

Grand Caillou.

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(3) Type of Habitat.

Project related features will be constructed within the following habitat types:

natural levees, lakes, swamps, marshes, canals, and bayous. The specific feature

and type of habitat to be affected is addressed in Table 2 below.

Table 2. Projected disturbance area by habitat type for construction features

impacting the project area.

Feature ID Feature Name Habitat Type

ED2 East Dredge Channel #2 Canal/Swamp Wetland Forest/Intermediate

Marsh/Brackish Marsh

ED3 East Dredge Channel #3 Canal/Intermediate Marsh/Swamp/Wetland

Forest/Brackish Marsh

ED5 East Dredge Channel #5 Canal/Wetland Forest

ED6 East Dredge Channel #6 Canal/Brackish Marsh

ED7 East Dredge Channel #7 Canal/Brackish Marsh

EP7 East Plug #7 Open Water

EG1 East Spoil Gap #1 Canal/Brackish Marsh

EG2 East Spoil Gap #2 Canal/Brackish Marsh

EX1 East Removal #1 Canal/Intermediate Marsh

EX2 East Removal #2 Canal/Intermediate Marsh

EC2 East Culvert #2 Canal/Brackish Marsh

EC3 East Culvert #3 Grand Bayou/Uplands/Canal

EC5 East Culvert #5 Bayou L'eau Blue/Uplands/Forested Wetland

EC6 East Culvert #6 St. Louis Canal

EC7 East Culvert #7 St. Louis Canal

EM1 East Marsh #1 Canal/Brackish Marsh

EM3 East Marsh #3 Canal/Saline Marsh

CC1 Central Culvert #1 GIWW

CC2 Central Culvert #2 GIWW

CC3 Central Culvert #3 HNC

CC4 Central Culvert #4 HNC

CC5 Central Culvert #5 Swamp/Wetland Forest

CC6 Central Culvert #6 Swamp/Wetland Forest

CC7 Central Culvert #7 Swamp/Wetland Forest

CC8 Central Culvert #8 Swamp/Wetland Forest

CC9 Central Culvert #9 Swamp/Wetland Forest

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CC10 Central Culvert #10 Swamp/Wetland Forest

CC11 Central Culvert #11 Swamp/Wetland Forest

CC12 Central Culvert #12 Swamp/Wetland Forest

CC13 Central Culvert #13 HNC

CC14 Central Culvert #14 Uplands

CC15 Central Culvert #15 Brackish Marsh

CD1 Central Dredge Channel

#1

Bayou Provost/Intermediate Marsh

CD1 Central Dredge Channel

#1

Bayou Provost/Swamp/Wetland Forest

CD2 Central Dredge Channel

#2

Bayou Butler

CD3 Central Dredge Channel

#3

Falgout Canal/Intermediate Marsh

CD6 Central Dredge Channel

#3

Swamp/Wetland Forest

CD6 Central Dredge Channel

#3

Freshwater Marsh

CD7 Central Dredge Channel

#7

Bayou Pelton/Swamp/Wetland Forest

CM2 Central Marsh Berm #2 Lake Boudreaux

CM3 Central Marsh Berm #3 Lake Boudreaux

CM4 Central Marsh Berm #4 Brackish Marsh

CP1 Central Plug #1 Robinson Canal

CP2 Central Plug #2 Canal

CS1 Central Diversion

Structure #1

HNC/Upland/Bayou Grand Caillou

CT1 Central Terracing #1 Saline Marsh

CT2 Central Terracing #2 Saline Marsh

CT3 Central Terracing #3 Saline Marsh

CT6 Central Terracing #6 Saline Marsh

CT7 Central Terracing #7 Saline Marsh

CT8 Central Terracing #8 Saline Marsh

CLV1 Central Levee #1 Swamp/Wetland Forest

CLV2 Central Levee #2 Swamp/Wetland Forest

WD2 West Dredge Channel #2 Carencro Bayou/Freshwater Marsh

WD3 West Dredge Channel #2 GIWW/Swamp

WP1 West Plug #1 Saline Marsh

WW2 West Weir #2 Grand Pass Channel

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(4) Timing and Duration of Discharge

The proposed project would have an initial direct impact on existing wetland

vegetation, wildlife and fisheries resources, and essential fish habitat within the

construction footprint. The dredge features WD2, CD1, CD3, CD6, ED2, ED3,

ED6, and ED7 would result in 148 acres of swamp, 343 acres of fresh marsh,

248 acres of intermediate marsh, and 182 acres of brackish marsh being directly

converted to open water. These features would also impact 614 acres of open

water habitat. Levee features (CLV1 and CLV2) would also result in 23 acres of

swamp being converted to upland. However, the project is expected to prevent

approximately 9,655 acres of marsh habitat loss over a 50-year period of analysis.

Dredged materials removed during excavation of new and enlargement of existing

conveyance channels would be deposited in a manner that would avoid

disruptions of water movement, flow, circulation and quality. Dredged material

deposition is not expected to result in significant or persistent water quality

impacts in the vicinity of construction activities. Any minor increases in

suspended sediment and turbidity levels during dredged material deposition

would be temporary and highly localized. Minor reductions in dissolved oxygen

levels associated with dredged material deposition would be temporary.

Several construction features (e.g., plug removal and installation, spoil gaps, weir

removal and installation, diversion structure installation, culverts, terrace berms

and marsh berms) associated with the proposed action would modify hydrologic

and sediment transport processes. The proposed project is designed to introduce

and/or divert fresh water to control salinities. Construction of the proposed

structures would also convey sediment and nutrients to the Northern Terrebonne

Marshes and elsewhere in the Terrebonne Basin to enhance fish and wildlife

habitat and productivity, and offset land loss. Areas modified by surface

alteration activities would, where applicable, be regraded and revegetated upon

feature installation. Potential impacts associated with surface alteration sites

would be minimized, as much as practicable, through the implementation of

stormwater pollution prevention plans (SWPPPs) and other applicable best

management practices (BMPs). Impacts associated with soil compaction, rutting,

rill, and gully erosion at surface alteration construction sites would be kept to a

minimum by use of proper construction techniques such as silt curtains,

temporary vegetative cover during construction, and regrading and permanent

vegetation establishment at the end of construction. The occurrence of low

dissolved oxygen conditions in the proposed project area waters would be

temporary and minor. The proposed action would directly create 257 acres of

brackish marsh and 72 acres of saline marsh as a result of features CM2, CM3,

CM4, CT1, CT2, CT3, CT6, CT7, CT8, EM1, and EM3.

F. Description of Disposal Method.

(a) Dredged materials, unless otherwise specified, will be disposed of in adjacent

spoil areas that are constructed by building berms. If it is determined that the

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dredge spoil can be used beneficially in other areas, the material will be used for

swamp nourishment, as proposed in the Bayou Pelton area (feature CD7).

(b) The plugs proposed in each subunit will be constructed from aggregate that will

be placed to an elevation of 2 feet above the water surface. The plug will be tiedin with 1 vertical to 4 horizontal slopes extending to the existing ground. The

aggregate will be placed with a track-hoe bucket and will most likely be brought

to the site via a barge or other floating vessel. It is assumed that access to the

sites is available or will be made available through flotation channels.

(c) Those areas proposed for culverts will be excavated to 2 feet below the proposed

flowline. The trench will be filled with 2 foot aggregate bedding material and

backfilled around the pipe. Culverts will be installed through roadways, natural

ridges, and dredged material embankments locally known as spoil banks. It is

assumed that access to the sites is available or will be made available through

flotation channels.

(d) Existing dredge spoil banks will be excavated to allow water conveyance and are

referred on the drawings as Spoil Gaps (see Appendix R drawing C-342 for

details). The gaps will be excavated 50 feet long and will be excavated with

track-hoes and back sloped to existing ground. The excavated material will be

either hauled off by the contractor or placed adjacent to the gap. All exposed

ground above the water surface will be seeded to reduce erosion. It is assumed

that access to the sites will be made available through flotation channels.

(e) Removal of existing structures will occur using equipment containing a bucket or

a grapple. The material will be removed off site and disposed at the contractors

discretion. It is assumed that site access is available or will be made available

through flotation channels. Two features will be removed from canals within

the East Grand Bayou Area. These features include a rock weir and an existing

soil plug.

(f) The Central Diversion Structure (CS1) consists of cast-in-place concrete inlet and

outlet monoliths supported on 14 inch by 14 inch precast prestressed concrete

piles. Lateral spacing of the piles will be 6.0 feet on center, and the pile tips will

be located at elevation -28.0 feet. A 4-inch stabilization slab will be placed

between the cast-in-place concrete substructures and the soil foundation. A steel

sheet pile scour wall will be placed around the perimeter of the inlet and outlet

monoliths. The pile tip elevation of the scour walls will be elevation -30.0 feet.

The precast concrete box culverts located between the inlet and outlet monoliths

will be supported on a 3.0 foot thick base of compacted material.

(g) Levees (listed as features CLV1 and CLV2) will be created out of dredged

disposal extracted from central canal dredge segments.

(h) Riprap used to construct the weir will be placed with a track-hoe bucket and will

most likely be brought to the site via a barge or other floating vessel. It is

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assumed that access to the sites is available or will be made available through

flotation channels.

(i) Terracing Berms will consist of a series of 10 foot wide parallel berms positioned

approximately 90 degrees to the direction of surge (See drawings C-341 for

details). Borrow trenches will be located a minimum of 25 feet away to prevent

sloughing. The exposed ground above the water surface will be vegetated to

reduce erosion. It is assumed that access to the sites is available or will be made

available through flotation channels.

(j) Material for marsh berm creation will be obtained by excavating in-situ material

adjacent to the berm location. Spill boxes will be placed in the berm to allow

water to drain. Containment berms will be filled with dredge material up to an

elevation of +2.5 feet to +3.0 feet. Booster pumps and effluent pipes will run

between the dredge borrow site and these marsh creation areas. It is assumed

from similar projects that the construction fill elevation of the dredged material

will settle over several years to an elevation of approximately +1.0 feet to +1.5

feet. Once this elevation is achieved, marsh vegetation can either be planted or

will reestablish naturally. All berms are expected to contain a 30 foot wide top

width and any exposed ground above the water surface will be seeded for erosion

protection. It is assumed that access to the sites is available or will be made

available through flotation channels.

II. FACTUAL DETERMINATIONS

A. Physical Substrate Determinations.

(1) Comparison of Existing Substrate and Fill.

(a) Dredge activities consist of the creation of two new water conveyance

channels for purposes of improving fresh water delivery. One of the channels

(ED5) will be installed through an area characterized as upland and has been

formerly altered to support a barge fleeting area and roadway infrastructure.

The second new channel (CD6) will be constructed through swamp and

freshwater marsh. A third new channel (WD2) will be constructed through

freshwater marsh. Swamp and marsh deposits consist mainly of very soft

clays and organic clays with peat that are generally less than 20 feet thick.

Direct impacts to soils and substrate from implementation of this projectrelated activity would primarily result from removal and disposal of the

excavated material.

(b) Deepening and widening of canals, bayous, and the GIWW from identified

project-related activities associated with features ED3, ED6, ED7, CD1, CD2,

CD3, CD4, CD7, and WD3 will result in direct impacts to the medium to stiff

silty clay substrate. The associated disposal of the dredged material will occur

along the dredged channel to create spoil banks that are elevated 6 to 8 feet

above the bank line. This activity will convert the smothered substrate to a

non-aquatic resource. However, much of the elevated berm will consist of

marsh edge species with more upland plant species colonizing the top and

upper side slopes of the berm which provides plant and habitat diversity. The

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spoil banks will aid in preventing saltwater intrusion and increase freshwater

residence time. One exception does exist as a result of the project and that is

in the area of feature CD7. This area will contain approximately 92 acres of

swamp nourishment that will result in a beneficial use of dredge material by

preventing the conversion of transitional wetlands to open water.

(c) Numerous channels have been dredged which cut through natural ridges

increasing both drainage and tidal exchange in the project area, exposing soils

to erosive forces. Three structural plugs will be installed into bayous and

canals with substrates consisting of medium to stiff silty clays. The plugs will

be created by discharging aggregate and sediment to a point where the feature

protrudes 2 feet above the waterline. The plugs are intended to retain

freshwater in marshes and prevent saltwater intrusion.

(d) Culverts will be installed through roadways, natural ridges, and existing spoil

banks. The culverts will interface with canals and bayous for purposes of

conveying or increasing freshwater movement into wetlands. Excavation of

the canal and bayou substrate is required at the interface locations to prepare

for the creation of a stable base to support the structure. The excavated area

would be backfilled with aggregate and permanently covered with the culvert.

(e) Existing dredge spoil banks will be excavated to allow water conveyance and

are referred to as Spoil Gaps. The excavated material will likely be placed

onto existing spoil banks that lie adjacent to the created gap.

(f) Two structural features, which include a rock weir and soil plug, will be

removed from canals within the East Grand Bayou Area. The materials will

be transported out of the project area and disposed of at an upland location.

(g) The Central Diversion Structure (CS1) will be constructed through an upland

area and will interface with the HNC and Bayou Grand Caillou. The

installation of this structure will result in substrate impacts and permanent fills

consistent with those addressed under culverts.

(h) Forced drainage levees CLV1 and CLV2 will be constructed through

freshwater swamps and marshes. Swamp and marsh deposits consist of very

soft clays and organic clays with peat that are generally less than 20 feet thick.

Direct impacts to soils and substrate from implementation of this projectrelated activity would primarily result from fill discharged to create the

elevated feature. The levees will be created out of soil and will permanently

convert 23 acres of wetland substrate to uplands. These project measures are

designed to work with several project features to deliver and retain fresh water

and to prevent greater saltwater intrusion into Lake Boudreaux.

(i) A riprap weir will be constructed within Grand Pass. Grand Pass likely

contains a medium to stiff silty clay substrate. The proposed structure will

consist of a rock filled sheet pile weir with boat openings and is intended to

constrict Grand Pass by 90 percent to minimize water exchange between

Bayou du Large and Caillou Lake.

(j) The Lake Boudreaux area is mapped on the soil survey as containing brackish

organic and mineral deltaic deposits. These bottom deposits would be

excavated in a series of trenches located approximately 25 feet from the base

of the proposed terrace berms. The excavated material will be side cast

covering the existing substrate and creating berms that extend 2 feet above the

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water surface and have a 10 foot top width. These berms are intended to

support marsh creation and retain freshwater in Lake Boudreaux.

(k) The marsh berms will be placed in the Grand Bayou area, within Lake

Boudreaux and brackish marsh. The substrate of Grand Bayou and Lake

Boudreaux are most likely medium to stiff silty clays. The brackish marsh

substrate consists of very soft clays and organic clays with peat that are

generally less than 20 feet thick. Direct impacts to substrate from

implementation of this project-related activity would primarily result from

removal and disposal of the excavated material. The side casted material

would be used to create berms that are 2.5 to 3.0 feet tall and contain a top

width of 30 feet. The berms are expected to settle to an elevation of +1.0 feet

to +1.5 feet. Once this elevation is achieved, marsh vegetation can either be

planted or will reestablish naturally.

(2) Changes to Disposal Area Elevation.

Feature ID Measure Name Approximate Change in

Disposal or Excavation Area Elevation (feet)

EC2 East Culvert #2 -4.5

EC3 East Culvert #3 -5.0

EC5 East Culvert #5 -14.0

EC6 East Culvert #6 -7.0

EC7 East Culvert #7 -7.0

ED2 East Dredge Channel #2 -8.0

ED3 East Dredge Channel #3 -14.0

ED5 East Dredge Channel #5 -14.0

ED6 East Dredge Channel #6 -14.0

ED7 East Dredge Channel #7 -14.0

EG1 East Spoil Gap #1 -0.5

EG2 East Spoil Gap #2 -0.5

EP7 East Plug #7 -5.0

EX1 East Removal #1 -5.0

EX2 East Removal #2 -5.0

EM1 East Marsh Berm #1 +3.0

EM3 East Marsh Berm #3 +3.0

CL1 Central Lock Complex #1 -7.0

CC1 Central Culvert #1 -20.0

CC2 Central Culvert #2 -20.0

CC3 Central Culvert #3 -10.0

CC4 Central Culvert #4 -5.0

CC5 Central Culvert #5 -5.0

CC6 Central Culvert #6 -5.0

CC7 Central Culvert #7 -5.0

CC8 Central Culvert #8 -5.0

CC9 Central Culvert #9 -5.0

CC10 Central Culvert #10 -5.0

CC11 Central Culvert #11 -5.0

CC12 Central Culvert #12 -5.0

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CC13 Central Culvert #13 -10.0

CC14 Central Culvert #14 -5.0

CC15 Central Culvert #15 -3.5

CD1 Central Dredge Channel #1 -10.0

CD2 Central Dredge Channel #2 -10.0

CD3 Central Dredge Channel #3 -10.0

CD4 Central Dredge Channel #4 -20.0

CD6 Central Dredge Channel #6 -10.0

CD7 Central Dredge Channel #7 -10.0

CLV1 Central Levee #1 +8.0

CLV2 Central Levee #2 +8.0

CP1 Central Plug #1 -10.0

CP2 Central Plug #2 -10.0

CS1 Central Diversion Structure #1 -10.0

CM2 Central Marsh Berm #2 +3.0

CM3 Central Marsh Berm #3 +3.0

CM4 Central Marsh Berm #4 +3.0

CT1 Central Terracing #1 +2.0

CT2 Central Terracing #2 +2.0

CT3 Central Terracing #3 +2.0

CT6 Central Terracing #6 +2.0

CT7 Central Terracing #7 +2.0

CT8 Central Terracing #8 +2.0

WW2 West Weir #2 -12.0

WP1 West Plug #1 -10.0

WD2 West Dredge #2 -7.0

WD3 West Dredge #3 -36.0

(3) Migration of Fill.

Of the 56 construction features associated with the proposed action, hydrologic

and sediment transport processes will be modified. The proposed project is

designed to introduce and/or divert fresh water to control salinities, convey

sediment and nutrients to the Northern Terrebonne Marshes and elsewhere in the

Terrebonne Basin. The proposed project will also enhance fish and wildlife

habitat and productivity, as well as offset land loss. Direct discharges of dredged

or fill material are intended for permanent placement, with anticipated settling of

the deposited material. The direct discharges of dredged and fill material have

been thoroughly studied and will be placed to benefit to the overall ecosystem.

Any minor increases in suspended sediment and turbidity levels during

construction would be temporary and highly localized. Also, soil compaction,

rutting, rill, and gully erosion at construction sites would occur. Impacts would

be kept to a minimum by use of proper construction techniques such as silt

curtains, temporary vegetative cover during construction, re-grading, and

permanent vegetation establishment at the end of construction.

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(4) Duration and Extent of Substrate Change.

Substrate will be permanently altered in those locations where levees, spoil banks,

terrace and marsh berms, culverts, plugs, weirs, and diversion structures are

proposed. These structures are essential to fulfill project objectives. Substrate

changes within those excavated canals and bayous generally consist of similar soil

types and textures, which results in a deeper water column over the inundated soil.

(5) Changes to Environmental Quality and Value.

Protection and enhancement of the project area is dependent on providing a

hydrologic regime that minimizes the physiological stress to wetland vegetation

from saltwater intrusion and tidal energy and is conducive to the retention of

locally provided fresh water and sediments. Several channels have been dredged

which cut through the natural ridges increasing both drainage and tidal exchange

in the project area, exposing the soil to erosive forces. Major navigation channels

in the subprovince are the Atchafalaya River, Wax Lake Outlet, HNC, GIWW,

and Lower Atchafalaya River (south of Morgan City). Each of these navigation

channels introduces and/or compounds marine influences in many of the interior

coastal wetlands and water bodies within the subprovince. Without action, the

Wetland Value Assessment analysis predicted that approximately 102,000 acres or

18 percent of remaining vegetated wetlands in the study area would be lost over

the 50-year period of analysis

The proposed action would have an initial negative direct impact on existing

wetland vegetation, wildlife and fisheries resources, and essential fish habitat

within the construction footprint. However, the proposed action is expected to

prevent approximately 9,655 acres of wetland from being converted to open water

by year 50 after project implementation. Based on the projected project benefits,

the proposed action will restore and maintain ecological integrity, including

habitats, communities, and populations of native species, and the processes that

sustain them by reversing the trend of degradation and deterioration in the project

area. The project is anticipated to contribute towards achieving and sustaining a

larger coastal ecosystem that can support and protect the environment, economy,

and culture of southern Louisiana and thus contribute to the economy and wellbeing of the Nation.

(6) Actions to Minimize Impacts.

Cost effectiveness analysis is used to determine what project features should be

built based on habitat benefits (outputs) that meet the goals and objectives of the

project and at the same time are the most cost effective. The Corps uses this

analysis in the evaluation process for all ecosystem restoration planning efforts.

After the cost effectiveness of identified alternatives has been established,

incremental cost analysis is conducted to reveal and evaluate changes in cost for

increasing levels of environmental output. While cost and environmental outputs

are necessary factors, other factors such as the ability to construct, schedule,

likelihood to achieve projected results, immeasurable environmental benefits, as

well as ancillary benefits were used in selecting the preferred alternative.

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The selected features have been designed to work with the natural, fluid, soft

environment of coastal Louisiana. Direct wetland impacts have been minimized

to the extent possible while striving to accomplish project objectives. As

previously stated, one of the project goals is to improve freshwater circulation and

redistribution within the study area. Project alternatives considered using various

freshwater delivery systems to achieve this goal and considered channels

extending from a variety of existing freshwater sources. A majority of the

proposed dredging activities will follow existing shallow sediment filled channels

(canals and bayous). Therefore, the proposed action reduces the length of newly

constructed linear channel needed for the project which minimizes direct wetland

conversions to open water conveyances.

Impacts associated with construction of features may include: increased total

suspended solids and turbidity, increased dissolved nutrient levels, mobilization

of existing contaminants in sediments, and decreases in dissolved oxygen levels.

These impacts would be minimized, as much as practicable, through the

implementation of SWPPPs and other applicable BMPs. Impacts associated with

soil compaction, rutting, rill, and gully erosion at surface alteration construction

sites would be kept to a minimum by use of proper construction techniques such

as silt curtains, temporary vegetative cover during construction, and re-grading

and permanent vegetation establishment at the end of construction. The

proposed action will decrease the rate of decline of various wetland types within

the study area to ensure their ability to provide geomorphic and hydrologic form

and function for the 50-year period of analysis. Marsh habitat for essential fish

and wildlife species will be sustained, mimicking as closely as possible conditions

which occur naturally in the area.

B. Water Circulation, Fluctuation, and Salinity Determinations.

(1) Alteration of Current Patterns and Water Circulation.

Major flow channels within the project area are the Atchafalaya River, the

GIWW, and the HNC. Generally, stages in the lower Atchafalaya River force

flow northeast through the Avoca Island Cutoff into the GIWW and Bayou

Penchant. Additional flow enters the GIWW from the Verret Basin through

Bayou Boeuf. Water travels eastward along the GIWW and through the Penchant

basin (west subunit). A portion of this water leaves the project area through the

Penchant basin along natural and man-made channels. The remaining flow

continues east along the GIWW. At Houma, the GIWW intersects the HNC

(central subunit). At this point, the majority of flow travels down the HNC to the

Gulf of Mexico. The remaining flow continues east along the GIWW. A small

amount of water enters the marshes of the Grand Bayou basin (east subunit)

through two channels, Company Canal and Bayou LEau Blue. Finally, the flow

exits the project area along the GIWW through the Bayou Lafourche ridge.

The proposed action will redistribute existing and increased flows of freshwater.

To achieve this, GIWW constrictions would be eliminated. Additionally, the

following measures to restrict increase, and control water are proposed for each of

the three subunits. In the West  Bayou Penchant Area, dredging, a sediment

plug, and a weir will be utilized. In the Central  Lake Boudreaux Area, culverts,

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levees, dredging, marsh terraces and berms, sediment plugs, modified operation of

the future HNC lock complex, and a large sluice gated box culvert are proposed.

In the East  Grand Bayou Area, culverts, dredging, gaps in canal spoil banks,

marsh berms, sediment plugs, and removal of a weir and soil plug are proposed.

Southeastern Penchant basin marshes (west subunit) would experience a flow

increase ranging from 100 to 3,000 cubic feet per second (cfs). Operation of the

HNC lock for environmental purposes would increase this flow benefit by an

additional 300 to 1,000 cubic feet/second (cfs). Flow through Grand Pass would

be reduced by 10 to 40 percent. High and low increases would correspond with

high and low Atchafalaya River stage, respectively.

Flow introduced to the Lake Boudreaux basin (central subunit) through the newly

dredged channels on the west side of the basin would range from 100 to 700 cfs.

With the closure of Robinson Canal and the construction of the marsh berm

features within the basin, the flows in Boudreaux Canal would increase

approximately 48 percent year round. High and low increases would correspond

with high and low Atchafalaya River stages, respectively.

Flows in the GIWW west of Grand Bayou would generally increase with

implementation of the proposed action. The increase would range from 0 to 20

percent west of Houma and could be as much as 50 percent east of Houma. These

increases stop as the GIWW reaches Grand Bayou. The additional flow through

Grand Bayou would cause the flow through Larose to reduce by as much as 50

percent. Flow increases into the Grand Bayou basin would range from 0 to 2,700

cfs throughout the year. Generally, the largest changes in flow would be seen

during high Atchafalaya stages and the smallest during low stages.

(2) Interference with Water Level Fluctuation.

Stage impacts in the western region of the project area would be limited to the

southeastern portion. Impacts of 0.1 to 0.2 feet would be seen from March to

September with the highest seen in July. These impacts would be attributed to the

reduced capacity of Grand Pass due to feature WW2 and from increased inflow to

this area from feature WD2.

In the central region of the project area stage impacts would be limited to the

Lake Boudreaux basin. Stage impacts would vary between 0.1 and 0.3 feet from

March to September, with the highest seen in July. These impacts would be

attributed to the increased flow into the basin through the culverts and dredged

channels connecting the Boudreaux basin to the HNC and from the closure of

Robinson Canal.

In the eastern region of the project area, impacts of up to 0.1 feet would be seen in

the Grand Bayou basin. These impacts would vary in duration throughout the

basin, with longer duration at the northern end, south of highway 24. Impacts

ranging from March through September would be the longest in this portion of the

project area. Stage reductions of up to 0.2 feet would also be seen along the

GIWW in the western portion of the project area. These too would be seen from

March to September with the largest reductions in July. Short duration impacts

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near the plug in Cutoff Canal would be as much as 0.4 feet. These impacts would

be highly localized to the area north of Bayou Pointe au Chien to Grand Bayou.

(3) Salinity Gradient Alteration.

Salinity levels throughout the project area are influenced by tides in the Gulf of

Mexico. Saline waters advance and retreat in channels and marshes with the tidal

cycle. As the land subsides and the marshes disappear, the limit of the saline

water advances further north. Salinity levels can also vary with seasonal wind

direction. In the fall and winter, southern winds push saline water into the

marshes. During other parts of the year, northern winds push water out of the

marshes, reducing salinity levels. Man made canals within the study area provide

efficient conduits for salinity to enter portions of the study area. These canals

include the HNC, Cutoff Canal, Robinson Canal, unnamed oil and gas exploration

canals, and pipeline canals. Areas projected to experience the greatest increases

in salinity are generally in the vicinity of the future location of the HNC lock

complex. In the central and eastern subunit areas, wetlands would continue to be

lost to subsidence, inundation of marsh plants, and subsequent erosion in brackish

and saline marshes. As these marshes disappear, salt water would begin to move

northward more rapidly, further stressing fresh and intermediate marshes. These

marshes would likely not tolerate the increasing salinity well and would probably

not convert to brackish marsh because the soils would be comprised of too much

organic matter.

Long-term direct impacts to water quality associated with implementation of the

proposed action would primarily be associated with changes in salinity and

nutrient concentrations of receiving waters. According to modeled salinity

values, changes in average annual salinities in the project area, as compared to the

No Action Alternative, generally range from increases of 2.0 parts per thousand

(ppt) to decreases of 4.7 ppt. Areas projected to experience the greatest decreases

in salinity values include the Lake Mechant area, Lake Boudreaux, and the Grand

Bayou area. In response to freshwater inputs and associated increased nutrient

inputs, indirect impacts of the proposed action would include long-term reduction

in losses of vegetation. Improved distribution of freshwater and nutrients would

enhance vegetative productivity and optimize conditions for maintenance of all

vegetative habitats. Most of the benefits from implementation of the proposed

action would be seen in the Lake Pagie area, south of Falgout Canal, in the Lake

Boudreaux area, and in the Grand Bayou area.

This LCA project proposes the development of an operational plan for the lock

complex structure authorized under Morganza to the Gulf in order to maximize

potential environmental benefits, both in terms of avoiding saltwater intrusion and

optimizing flow distribution. The proposed action with a constructed lock

complex (which comprises the Future-Without-Project condition for the LCA

project after 2025) is to operate it in such a way that freshwater from the GIWW

escaping down the HNC could be redirected into the surrounding wetlands.

The lock itself will be operated only when the floodgates are closed to reduce

salinity within the channel. Once closed, the floodgates would force water down

other waterways (such as Bayou Grand Caillou). Saltwater intrusion is halted at

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the gate, and freshwater flows increase in other waterways. If the HNC Lock is

not constructed by 2025, the benefits of its operation would be lost and other

benefits from LCA-ARTM from 2025 onward would be significantly altered.

(4) Cumulative Effects on Water Quality.

a. Salinity. Salinity levels would decrease or stabilize throughout most of

the project area with slight increases in salinity levels expected in areas

near the HNC lock complex. This alternative would have positive

synergistic effects on salinity levels when combined with other Federal,

state, local, and private restoration efforts. Changes in marsh health,

stratification and mixing patterns, and flow patterns in the project due to

project features could have a minor effect on tidal flows which could

affect salinities. With implementation of the proposed action, the coastal

plain of Louisiana would be affected by other activities and programs that

would have both cumulatively beneficial and detrimental effects on water

quality conditions. Some of these past, present, and foreseeable future

activities include state and local water quality management programs;

national level programs to address hypoxia in the northern Gulf of

Mexico; oil and gas development; industrial, commercial, and residential

development; and Federal, state, and local navigation and flood-damage

reduction projects.

b. Clarity. Suspended sediment loads to receiving areas within the

Terrebonne Basin would be increased. The southeast portions of the

Penchant basin would receive additional suspended sediment loads due to

feature WD2. Northern Boudreaux Basin would receive suspended

sediments brought through the GIWW to the HNC. These sediments

would be distributed throughout the Boudreaux Basin. An increased

amount of suspended sediment would reach the Grand Bayou basin.

These sediments would be distributed to the marshes east of Grand Bayou

with a much smaller portion exiting the basin through Cutoff Canal due to

feature EP7. Operations of the HNC lock would increase suspended

sediments to the marshes between the HNC and Bayou Du Large. There

would be a decreased suspended sediment load south of the HNC lock.

With the delivery of increased sediment comes increased turbidity which

reduces water clarity. This parameter is expected to change with the

implementation of the design features.

c. Color. The proposed action will redistribute existing freshwater flows to

benefit project area marshes, but this redistribution of flow would

permanently alter water color from its current state due to increased

sediment delivery. This change is desired as part of the proposed action to

facilitate marsh nourishment and marsh platform development and reduce

land loss. The primary areas where changes in water color will be most

apparent is along the GIWW, connecting channel conveyances, and

adjoining marshes. However, there would be a decreased suspended

sediment load south of the HNC lock.

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d. Water Chemistry and Dissolved Gasses. The redistribution of freshwater

within the Terrebonne Basin would immediately change the water

chemistry of receiving areas. Materials excavated to provide features of

the proposed action would contain variable concentrations of organic

material. Decomposition of organic material within the placement sites

may result in a local, temporary reduction in dissolved oxygen or release

of ammonia. However, hydrologic exchange between the dredged

conveyances and surrounding marshes would reduce dissolved oxygen

deficits and facilitate the transformation of ammonia into non-toxic nitrate.

The redistribution of fresh water into the basin may increase dissolved

oxygen concentrations, particularly during summer.

e. Temperature. The overall project is expected to decrease water

temperatures and result in fewer water temperature fluctuations with the

distribution of regular supply of freshwater. The establishment of

vegetative communities will also contribute in moderating water column

temperatures particularly during the growing season.

f. Nutrients. One of the stated project goals is to rebuild eroded wetlands in

the area through the diversion of fresh water, sediment, and nutrients. The

proposed project and all of its features will function together to elevate

water quality constituents such as nutrients, thereby increasing

organic/nutrient enrichment of the water column. Improved distribution of

freshwater and nutrients would enhance vegetative productivity and

optimize conditions for maintenance of all vegetative habitats, benefitting

the extensive fish and wildlife resources of the area. In summary,

nutrients help promote marsh building which suppresses the current land

loss trend.

(5) Changes to Environmental Quality and Value.

Changes may be beneficial or detrimental, depending on human perceptions and

the water uses. The change from a less fresh to a fresher system could be

perceived as beneficial to wetland nourishment, but detrimental to recreational

use because of water color changes, and possible changes in fish species

assemblages in the recreational area. However, the changes in water chemistry

would mimic natural conditions prior to the Northern Terrebonne Marshes partial

separation from the influence of the Atchafalaya River. Stabilization of salinity

regimes would probably aid resource managers, commercial and recreational

fisheries managers, and water users in making long-term decisions. Salinity could

be either beneficial or detrimental, depending on the user group. Salinity is not

necessarily a pollutant in coastal waters. Fresh water marshes, however, are

sensitive to salinity levels, but the varying levels of salinity have positive impacts

on various commercial and recreational fisheries. On balance, the stabilization of

salinities, or the relocation of saltier water zones gulfward, would help to achieve

the goals of the proposed project. The collective effect on water quality of the

Terrebonne Basin resulting from this project would be a synergistic positive result

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over and above the additive combination of impacts and benefits of the other

alternatives.

(6) Actions Taken to Minimize Impacts.

The future quality of Louisianas coastal waters depends on a responsible,

watershed approach to managing these activities. There are a number of present

and future activities that would continue to occur without the proposed actions of

the project and would affect surface water quality conditions in the coastal plain

of Louisiana. Although there is Federal, state and local regulations in place to

ensure protection of Louisianas public health and natural resources, water quality

conditions would likely improve with the programs in place. There is also

Federal, state, local and private ecosystem restoration projects being studied and

undertaken to improve water quality conditions within the LCA.

However, there are some activities that may potentially have negative effects on

water quality and will continue to occur with or without the proposed project.

Industrial, commercial, and residential development along the coast. With

this activity comes increased point and nonpoint source pollution from sources

such as wastewater treatment facilities and urban runoff from new

development. Also, activities associated with maintaining and improving

navigation along the coast would continue to occur.

Flooddamage reduction projects would continue to be planned, designed, and

constructed especially in areas highly susceptible to flood damages due to

hurricanes and tropical storm events. With these activities, more alterations to

the hydrology of the coast would potentially occur leading to areas of

degraded water quality. Some projects, such as the Morganza to the Gulf

Hurricane Protection Project, are incorporating resource sustainable design

techniques that may aid in protecting significant resources such as surface

waters of the state.

The most notable activity that would continue to occur without the proposed

LCA Plan is the ongoing erosion/subsidence or land loss of the coastal areas.

This would continue to unearth the expansive oil and gas infrastructure along

the coast of Louisiana. This would be a precarious situation, especially during

storm events and within navigable waterways. Exposed pipelines are

vulnerable to navigation vessels striking them, which could lead to discharges

into the Gulf of Mexico as well as other coastal water bodies. In the event of

discharges, extensive ecological damage would probably occur. The owner(s)

of the infrastructure could incur expensive fines and cleanup costs and vessel

operators could be seriously injured. There are other forms of infrastructure

that could potentially be exposed due to coastal erosion including wastewater

collection systems and other commercial industry related systems.

Therefore, there are no unavoidable adverse impacts as a result of the

implementation of reasonable alternatives for this project. Where possible,

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dredge channels excavated for increased fresh water conveyance will utilize

currently existing canals, which will reduce the length of newly constructed linear

channel needed for the project and minimize adverse impacts to wetlands

associated with channel excavation.

Potential impacts associated with surface alteration sites would be minimized, as

much as practicable, through the implementation of SWPPPs and other applicable

BMPs. Impacts associated with soil compaction, rutting, rill, and gully erosion at

surface alteration construction sites would be kept to a minimum by use of proper

construction techniques such as silt curtains, temporary vegetative cover during

construction, and regrading and permanent vegetation establishment at the end of

construction. The occurrence of low dissolved oxygen conditions in the proposed

project area waters would be temporary and minor.

C. Suspended Particulate / Turbidity Determinations.

(1) Alteration of Suspended Particulate Type and Concentration.

The lack of marsh forming sediments from riverine environments has accelerated

the degradation of all marsh types. Opportunities exist to re-introduce sediments

from the Atchafalaya River and several bayous and to use on site sediments

displaced by gulf storm events to create new marsh area. Suspended sediment

loads are expected to increase within the project area as part of the design.

However, suspended particulate concentrations were not analyzed as part of the

study. Historically, the Atchafalaya River and Bayou Lafourche were sources of

sediment to the project area. Sediments from these waters would be delivered

throughout the project area during annual floods through systems of distributary

channels and through overland flow.

Short-term direct impacts associated with construction of features could include

increased total suspended solids and turbidity. These impacts would be

minimized, as much as practicable, through implementation of appropriate Best

Management Practices. Any increases in suspended solids and turbidity levels

due to dredging related activities in the immediate project area would be minor,

temporary, and highly localized.

(2) Particulate Plumes Associated with Discharge.

Any minor increases in suspended sediment and turbidity levels during dredge

disposal would be temporary and highly localized. Minor reductions in dissolved

oxygen levels associated with dredged material deposition would be temporary.

Potential impacts associated with surface alteration sites would be minimized, as

much as practicable, through the implementation of stormwater pollution

prevention plans (SWPPPs) and other applicable best management practices

(BMPs). Impacts associated with soil compaction, rutting, rill, and gully erosion

at surface alteration construction sites would be kept to a minimum by use of

proper construction techniques such as silt curtains, temporary vegetative cover

during construction, and regrading and permanent vegetation establishment at the

end of construction.

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(3) Changes to Environmental Quality and Value.

Based on data from Gulf of Mexico gages, regional sea level rise is approximately

0.75 feet/century and based on gages at Grand Isle and Eugene Island, subsidence

in the project area is approximately 2.35 feet/century. This resource is technically

significant because it is a critical element of coastal habitats, and supports

vegetation growth and open-water benthic productivity.

By increasing suspended sediment loads to receiving areas, the southeast portions

of the Penchant basin would receive additional suspended sediment loads due to

feature WD2. Northern Boudreaux Basin would receive suspended sediments

brought through the GIWW to the HNC. Theses sediments would be distributed

throughout the Boudreaux Basin. An increased amount of suspended sediment

would reach the Grand Bayou basin. These sediments would be distributed to the

marshes east of Grand Bayou with a much smaller portion exiting the basin

through Cutoff Canal due to feature EP7. Operations of the HNC lock would

increase suspended sediments to the marshes between the HNC and Bayou Du

Large. This activity decreases marsh fragmentation and increases overall marsh

acreage while improving fish and wildlife habitat and productivity.

(4) Actions to Minimize Impacts.

Construction operations are expected to temporarily increase the concentration of

suspended particulates. Particulates suspended during project construction would

dissipate after construction activities are complete. Temporary increases in

suspended particulates will be minimized as much as possible through BMPs such

as creating containment berms, use of silt fencing, silt curtains, and seeding, to

prevent the unnecessary transport of sediments within the construction and

placement areas.

D. Contaminant Determinations.

As reported in the Phase I ESA, during records research and site reconnaissance it

was determined that areas adjacent to some of the project features contained Few

Recognized Environmental Conditions (RECs) that presented a low to moderate

risk of affecting potential project features, albeit that no RECs were noted within

direct proximity of land associated with any of the potential project features.

Should at anytime during the project HTRW concerns arise, the CEMVN would

take immediate actions to investigate the concerns. Should an HTRW issue be

determined and the development of a response action required, CEMVN would

coordinate with the appropriate Federal and state authorities to implement an

approved response action.

Consistent with ER 1165-2-132, an HTRW investigation of the project area was

conducted. Based upon findings from this investigation, the potential for direct

impacts to the project area from implementation of the proposed action would be

low and would likely continue to be low into the future.

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The mobilization of existing contaminants in sediments into the project area may

suspend some pollutants, which include primarily trace metals and hydrophobic

organic compounds from the Atchafalaya and Mississippi Rivers streambed

sediments. However, these contaminants are not expected to occur in such

quantities that they would impair water quality or be harmful to humans, fish, or

wildlife.

E. Aquatic Ecosystem and Organism Determinations.

(1) Effects on Plankton.

Increases in freshwater flows and associated nutrients from proposed features

would be expected to change plankton abundance and species composition.

Changes in plankton species assemblages would likely be similar to what is

observed along present day estuarine salinity gradients except that increased

freshwater flows would shift the plankton community, displacing marine species

in favor of fresher and more estuarine, euryhaline species. During actual

construction activities of project features there would only be short-term minor

adverse impacts to plankton populations due to increases in turbidity, low

dissolved oxygen, and introduction of dredged sediments into shallow open water

areas. There would be long-term loss of shallow water habitats due to dredge

disposal activities. However, there is an abundance of shallow open water habitat

available for use by plankton. Indirect impacts to plankton resources would

primarily be related to increases in the export of dissolved organic compounds

and detritus from enhanced marsh habitats that would benefit local plankton

populations by increasing the planktonic food web. It is unknown whether

proposed diversion flows and associated nutrients would result in noxious blooms

of blue-green algae, but there is likely some upper limit to the assimilation of

nutrients into estuarine waters, beyond which blooms would occur.

(2) Effects on Benthos.

Smothering of non-mobile benthic organisms could occur. These impacts would

be minimized, as much as practicable, through implementation of appropriate

Best Management Practices. Construction of proposed features and dredging

activities would destroy existing benthic communities at the proposed

construction sites. In addition, introduction of additional freshwater into estuarine

systems could have short-term impacts on benthic populations in receiving

waters. Introduction of freshwater flows from proposed features would be

expected to change benthic abundance, species composition, and species

distribution. Changes in benthic species assemblages would likely be similar to

what is observed along present day estuarine salinity gradients except that

increased freshwater flows would shift the benthic community, displacing marine

species in favor of fresher and more estuarine, euryhaline species.

Species richness of benthic communities is usually greater in higher salinity

waters (Day et al. 1989). Decreases in salinity would likely reduce benthic

species richness as greater volumes of freshwater are pushed deeper into estuarine

basins.

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(3) Effects on Nekton.

Nekton comprise animals largely from three clades; vertebrates, mollusks, and

crustaceans. Direct impacts to nekton from implementation of the proposed

action would result from construction of project features. Impacts from

construction of water control structures may include direct mortality due to burial

or sudden salinity changes; injury or mortality due to increased turbidity (e.g. gill

abrasion, clogging of feeding apparatus); modified behavior, and short-term

displacement. Dredging and placement of borrow material associated with dredge

features, terracing, and marsh creation would negatively impact benthic

organisms and benthic feeders in dredge channels and disposal areas. Sessile and

slow-moving aquatic invertebrates would be disturbed by the dredge or

excavation activity or buried by the placed material. Construction activities

would temporarily increase turbidity, temperatures, and biological oxygen

demand (BOD), and decrease dissolved oxygen. These temporary conditions

would likely displace more mobile nekton from the construction area. Following

construction, displaced nekton would likely return to the project area.

Direct impacts to nekton would also result from changes in salinity levels in the

project area as a result of water control structures. Areas projected to experience

the greatest increases in salinity are generally in the vicinity of the future location

of the HNC lock complex. These changes in salinities may change the

distribution of fish and shellfish species based on their salinity tolerance. In areas

freshened by water control structures, species assemblages would be expected to

shift toward the Gulf. Less freshwater tolerant species, such as brown shrimp and

spotted seatrout, may be displaced from freshened areas. Species such as Gulf

menhaden, blue crab, white shrimp, and red drum that commonly utilize low to

medium salinity areas and SAV habitats would likely benefit. Freshwater fishery

species, such as crawfish, catfish, largemouth bass, and other sunfish should

benefit from implementation of the RP. Conversely, in areas that see an increase

in salinities, more saltwater-tolerant species such as brown shrimp and spotted

seatrout would move further into area estuaries. For oysters, changes in salinities

outside of their optimum range (5-15ppt) could increase mortality, affect

reproduction, and affect spat settlement. Likewise, in areas that are currently too

fresh or too saline to support healthy oyster populations, changes in salinity due to

project implementation could provide new areas for oyster production.

Indirect benefits to nekton should result from increased productivity, land

building, and acreage of marsh and submerged aquatic vegetation habitats that are

supportive of freshwater, estuarine, and marine fishery species. Subsidence and

predicted sea level rise would be less likely to increase open water habitats. The

ARTM project is designed to prevent or slow the loss of marsh habitat in the

project area and generally improve conditions for SAV and other highly

productive forms of essential fish habitat. Inflows of fresh water and nutrients are

expected to create and maintain wetlands, which provide food and cover to

juvenile fish, shrimp, crabs, oysters, and other biota. As a result, the project area

would be expected to better maintain most of its current ability to support nekton

as well as those that are estuarine-dependent. Potential increases in submerged

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aquatic vegetation will increase the habitat required for juveniles to escape

predation.

(4) Effects on the Aquatic Food Web.

Louisianas coastal wetlands are the richest estuaries in the country for fisheries

production. Commercially and recreationally important species such as brown

and white shrimp, blue crabs, eastern oysters, and menhaden are abundant.

Louisiana has historically been an important contributor to the Nations domestic

fish and shellfish production, and is one of the primary contributors to the

Nations food supply for protein. While Louisiana has long been the Nations

largest shrimp and menhaden producer, it has also recently become the leading

producer of blue crabs and oysters.

Phytoplankton are the primary producers of the water column, and form the base

of the estuarine food web. Zooplankton provide the trophic link between the

phytoplankton and the intermediate level consumers such as aquatic invertebrates,

larval fish, and smaller forage fish species (Day et al. 1989). Although direct

impacts will occur through implementation of project features, it is the indirect

project impacts to plankton resources that demands attention. Indirect impacts

would primarily contribute to increases in the export of dissolved organic

compounds and detritus from enhanced marsh habitats that would benefit local

plankton populations by increasing the planktonic food web. This resource is

technically significant because plankton provide a major, direct food source for

animals in the water column and in the sediments.

The associated project features will provide inflows of fresh water and nutrients

which are expected to create and maintain wetlands. The wetlands will in turn

provide food and cover to juvenile fish, shrimp, crabs, oysters, and other biota.

As a result, the project area would be expected to better maintain most of its

current ability to support Gulf of Mexico Fishery Management Council (Councilmanaged) species (such as white shrimp, brown shrimp, and red drum), as well as

the estuarine-dependent species (such as spotted seatrout, gulf menhaden, striped

mullet, and blue crab) that are preyed upon by other Council-managed species

(such as mackerels, red drum, snappers, and groupers) and highly migratory

species (such as billfish and sharks). Marsh habitats protected by the proposed

action would serve as important and essential transitional wetland habitats used

by fishery resources for spawning, foraging, cover, nursery, and other life

requirements. In summary, the proposed action would have positive synergistic

effects at all levels of the aquatic food web.

(5) Effects on Threatened and Endangered Species.

The No Action Alternative would result in the continued degradation and loss of

important and essential fish and wildlife habitats used by many different fish and

wildlife for shelter, nesting, feeding, roosting, cover, nursery, and other life

requirements. The loss and deterioration of transitional wetland habitats would

continue to impact, to some undetermined degree, all listed species that

potentially utilize the project area including: West Indian manatee, piping plover,

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pallid sturgeon, Gulf sturgeon, green sea turtle, hawksbill sea turtle, Kemps

Ridley sea turtle, leatherback sea turtle, and loggerhead sea turtle.

Continued coastal land loss and deterioration of critical coastal habitats is

anticipated to impact all listed species that utilize them. This alternative would

have positive synergistic effects on listed species when combined with other

Federal, state, local, and private restoration efforts. The proposed action is not

likely to adversely affect any threatened or endangered species or any designated

critical habitat in the project area. It is unlikely that any of the features associated

with implementation of proposed action would present significantly adverse

indirect impacts to any threatened or endangered species or critical habitat. On

the contrary, all restoration features would likely provide a net increase of coastal

wetland habitats potentially used by these species.

(6) Effects on Other Wildlife.

Direct adverse impacts to wildlife resources would primarily result from

construction activities associated with the various features of the proposed action.

Some wildlife species could be temporarily displaced from an area as disturbance

from construction activities could result in unfavorable conditions for nesting,

foraging, and/or other activities. However, most species would move to an area

with more favorable conditions and return after construction is completed.

Permanent displacement may occur with the construction of permanent project

features. Any permanent displacement would be offset by the benefits associated

with restoration.

In order to minimize any potential impacts to nesting bald eagles that may be

found in the project area, project implementation would follow the National Bald

Eagle Management Guidelines. The guidelines recommend:

maintaining a specified distance between the activity and the nest (buffer area)

maintaining natural areas (preferably forested) between the activity and nest

trees (landscape buffers); and

avoiding certain activities during the breeding season

In order to minimize any potential impacts to colonial nesting waterbirds that may

be found in the project area, a qualified biologist would inspect the proposed work

site for undocumented nesting colonies during the nesting season prior to

construction. To minimize disturbance to colonial nesting waterbirds, the

following restrictions on activity would be observed:

for colonies containing nesting brown pelicans, all activity occurring within

2,000 feet of a rookery would be restricted to the non-nesting period

(September 15 through March 31)

for colonies containing nesting wading birds, anhingas, and/or cormorants, all

activity occurring within 1,000 feet of a rookery would be restricted to the

non-nesting period (September 16 through April 1)

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Indirect impacts to wildlife resources resulting from the proposed project would

include the creation, restoration, and protection of wetland habitats utilized by

species for nesting, rearing of young, resting, and foraging activities. An increase

in wetland acreage and quality (compared to the Future Without-Project

conditions) would provide nesting, brood-rearing, and foraging habitat for

resident avian species. Migratory avian species would also benefit from the

proposed project as important stopover habitat would be protected for neotropical

migrants and wintering habitat would be created/protected for waterfowl. Game

mammals and furbearers would also benefit from the protection of wetland types

favored by the majority of those species. Reptiles and amphibians, which prefer

fresher wetland types, would also benefit from the reduction in loss of wetland

acres.

In summary, the project will reverse the current trend of 1,844 acres of wetland

loss per year within the project area as a result ecosystem degradation.

Land loss leads to increased competition between local wetland-dependent

wildlife populations for decreasing resources; displacement to other more suitable

wetland areas; and localized decline in wetland-dependent wildlife populations.

The project will improve habitat and would lead to increased habitat for wetlanddependent wildlife; decreased competition for resources; and localized

stabilization or improvement in wetland-dependent wildlife populations.

(7) Actions to Minimize Impacts.

Formulation of project plans and designs, evaluation of alternative plans, and

development of operational scenarios for the preferred alternative, have all been

conducted with the objective of minimizing potential negative impacts to the

aquatic ecosystem. Study alternatives were developed in accordance with Corps

planning guidance at ER 1105-2-100 which directs that ecosystem restoration

projects be designed to avoid the need for compensatory fish and wildlife

mitigation. Formulation of project alternatives was conducted in compliance with

this guidance. Only Alternative 7 would result in a net loss of emergent marsh

habitat and would, therefore, require mitigation. Alternative 7 was not selected as

the National Ecosystem Restoration plan or the Recommended Plan.

F. Proposed Disposal Site Determinations.

Discussions pertaining to turbidity and suspended particulates are summarized under

Section II. C in this document. Contaminants were discussed previously under

Section II. D of this Evaluation. Implementation of the proposed project will have no

significant adverse effects on municipal or private water supplies; recreational or

commercial fisheries; water related recreation or aesthetics; parks; national

monuments; or other similar preserves. Any adverse impacts will be minor and of

short-term duration. An application for State water quality certification under Section

401 of the Clean Water Act is being submitted to the Louisiana Department of

Environmental Quality.

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G. Determination of Cumulative Effects on the Aquatic Ecosystem.

Cumulative effects on the coastal ecosystem would primarily be related to the

incremental impact of all past, present, and future actions affecting water quality

within the Basin such as: increase in fresh water areas; stabilization or decrease in

salinities; increase in sediment introduction to the coastal zone, with accompanying

minor increases in trace metals associated with bed sediments; increased total

suspended sediments; increased turbidity; increased organic/nutrient enrichment of

the water column; disturbance and release of possible contaminants; decrease in water

temperatures along with fewer water temperature fluctuations; and increased

dissolved oxygen levels. Likewise, there are no adverse alterations or destructions of

unique or valuable habitats, critical habitat for endangered species, important wildlife

or fishery breeding or nursery areas, designated wildlife management or sanctuary

areas, or forestlands. No adverse cumulative or secondary impacts to the biological

productivity of wetland ecosystems are anticipated. Adverse disruptions of coastal

wildlife and fishery migratory patterns are not anticipated.

The RP would have positive synergistic effects on the aquatic environment and the

vegetation and wildlife it supports particularly when this project is anticipated to

function in combination with other Federal, state, local, and private restoration

efforts. A net total of 9,655 acres of wetlands would be protected, created, and

nourished as part of this project.

H. Determination of Secondary Effects on the Aquatic Ecosystem.

The ARTM project is designed to prevent or slow the loss of marsh habitat in the

project area. This objective will be accomplished by re-introducing fresh water

supplies which balances the altered salinity regime, improves the viability of fresh

water marsh plant life and restores fish and wildlife habitats. These project features

will change marsh health, stratification and mixing patterns, flow patterns, and

increase sediment distribution through a much of the project area. These features

could have a minor effect on tidal flows which affects salinities within the project

area but these activities are not expected to contribute to degradation of the coastal

marshes. Rather, the ecosystems response to freshwater inputs and associated

increased sediment and nutrient inputs, would increase plant productivity and vertical

accretion of organic soils, increase diversity of natural vegetative communities, and

reduce vulnerability to invasive species threats. Indirect benefits to fish and wildlife

would result from increased productivity, land building, and acreage of marsh and

submerged aquatic vegetation habitats.

Therefore, the project features associated with implementation of the preferred

alternative would not result in significantly adverse indirect impacts to water quality,

threatened or endangered species, essential fish habitat, water bottoms, plankton,

vegetation, wildlife, or fisheries.

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III. FINDINGS OF COMPLIANCE OR NON-COMPLIANCE WITH THE

RESTRICTIONS ON DISCHARGE

A. No significant adaptations of the guidelines were made relative to this evaluation

B. No practicable alternatives to the proposed discharges could be identified that would

have less adverse impacts on the aquatic ecosystem.

C. Chemical constituents of the dredged material released during dredging and disposal

operations are not expected to exceed LA Water Quality Standards.

D. The proposed action is compliant with the Endangered Species Act of 1973, as

amended. The proposed action would not significantly affect endangered or threatened

species or their critical habitats.

E. The proposed action is compliant with specified protection measures for marine

sanctuaries designated by the Marine Protection, Research, and Sanctuaries Act of 1972.

All disposal sites and effects are inland waters. No effects would occur in ocean waters

beyond the shoreline of the Gulf of Mexico.

F. Evaluation of Extent of Degradation of the Waters of the United States.

(1) Effects on Human Health and Welfare

a. Municipal and Private Water Supplies.

Implementation of this RP is not anticipated to have any direct impacts to

drinking water supply or agricultural water use. The additional flow into the

southeastern Penchant, Lake Boudreaux, and Grand Bayou basins would work to

slow salt water intrusion in these areas. Slowed marsh loss would delay the

intrusion of salt water to populated portions of the project area. Decreased flow

through the GIWW at Larose could increase the intrusion of salt water in Bayou

Lafourche. This could result in the loss of agricultural water use in Bayou

Lafourche south of Larose; however this is the outcome of the No Action

Alternative.

b. Recreational and Commercial Fisheries.

Direct impacts to commercial fisheries from implementation of the RP would

primarily be related to reduced or impeded access to fishing areas. Feature WP1

would block access to a small area of saline marsh near Lake Mechant. The

modified operation of the HNC lock complex (CL1) would block vessel

movement in the HNC; however, other routes (e.g. Bayou Grand Caillou) would

remain open. The plug in Robinson Canal would prevent vessel movement

between Lake Boudreaux and Bayou Petit Caillou, limiting ingress and egress

from the east to Boudreaux Canal. Feature WW2 would restrict movement of

vessels with a draft greater than 12 feet. Feature EP7 would restrict movement

of vessels with a draft greater than 5 feet.

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Anticipated indirect impacts on commercial fisheries include affecting the

location of target species. Changes in salinity levels in the project area as a

result of project features would change the distribution of fish and shellfish

species based on their salinity tolerance. Changes in fisheries distribution would

impact commercial fishing patterns and locations. However, the project is

expected to benefit commercial fisheries by decreasing the rate of marsh loss in

the project area as compared to the No Action Alternative.

The Penchant marshes (west subunit) contain high quality floating marsh habitat

providing prime freshwater based recreational bass fishing. Potential positive

effects of redistributing freshwater flows include marsh nourishment around the

Penchant basin marshes and pushing freshwater further south and east to nourish

and stabilize deteriorating fresh, intermediate and brackish marsh in the east and

south portions of the west subunit. Periods of high Atchafalaya River would

likely result in temporary increases in turbidity, which may temporarily reduce

recreational fishing success.

In the Central subunit the potential impacts from the installation of flow

management features and associated redistribution of freshwater would be

similar to those effects in the West region. Freshwater flows are expected to

result in some reduction in salinity levels, and help to stabilize fresh,

intermediate, and brackish marsh in and around Lake Boudreaux and the Central

region. Therefore, freshwater based recreational fishing should improve and

current levels of recreational saltwater fishing would possibly be maintained.

Improved freshwater flow measures in the east subunit would have similar

effects to recreational and commercial fisheries as described for the Central

region. In particular, recreational fishing and shrimping at Pointe Au Chien

Wildlife Management Area would benefit as additional freshwater from the

improved flow measures would improve habitat for all of these species.

c. Plankton.

Project related activities will increase freshwater flows and associated nutrients

is expected to change plankton abundance and species composition. Changes in

plankton species assemblages would likely be similar to what is observed along

present day estuarine salinity gradients except that increased freshwater flows

would shift the plankton community, displacing marine species in favor of

fresher and more estuarine, euryhaline species. Therefore, the anticipated

increase and preservation of marsh habitats will benefit local plankton

populations by increasing the planktonic food web.

d. Fish.

The project area supports one of the most productive fisheries in the Nation.

However, wetland habitat losses would decrease the productivity of Louisianas

coastal fisheries. The commercial fishing industry would suffer significant

losses in employment as estuaries that are necessary to produce shrimp, oysters,

and other valuable species erode. Job losses would occur in the areas reliant on

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fishing, harvesting, processing, and shipping of the seafood catch. Thus, changes

in existing fisheries habitat caused by wetland loss, saltwater intrusion, and

reduced salinity gradients would likely increase the risk of a decline in the

supply of nationally distributed seafood products from Louisianas coast.

Declines in fishery productivity are expected to be reduced in these areas through

project implementation, and the long-term sustainability of a productive fishery

would be more likely than with No Action.

e. Shellfish.

Although the conversion of marsh into open water will likely provide temporary

new oyster habitat, the quality of this habitat is expected to decrease as

populations become stressed by increased saltwater intrusion, predation, and lack

of adequate shelter resulting from marsh erosion. Once buffered by interior and

barrier wetlands, oyster reefs will be exposed directly to the gulf as surrounding

marshes erode. The band of intermediate salinity necessary for oyster

production would likely narrow significantly leading to a net loss in oyster

populations. Therefore, the seafood industry would suffer significant losses in

employment as estuaries that are necessary to produce oysters, and other

valuable species erode, resulting in job losses related to harvesting, processing,

and shipping of the seafood. Thus, changes in existing fisheries habitat caused

by wetland loss, saltwater intrusion, and reduced salinity gradients would likely

increase the risk of a decline in the supply of nationally distributed seafood

products from Louisianas coast. Implementation of the RP is expected to

benefit commercial harvest of oysters by decreasing the rate of marsh loss in the

project area which assists in sustaining optimal habitat and areas of greatest

productivity.

f. Wildlife.

The greatest threat to wildlife resources across the project area is the ongoing

loss of coastal wetlands in the Terrebonne Basin. In the eastern Terrebonne

Basin, most wildlife populations are expected to decline due to high land loss.

Similarly, with less freshwater and intermediate marsh habitat, waterfowl

hunting opportunities would likely decrease. Ridge habitat would also likely

continue to decline, reducing opportunities for deer and other small game

hunting.

Planned and on-going restoration measures along with the proposed project will

likely be beneficial to the ecosystem and wildlife in numerous ways as habitat

for various stages in the life-cycles are stabilized, protected, improved, and

expanded. Marsh and ridge restoration will improve vegetation and habitat for

birds and wildlife and will enhance opportunities for birding, hunting, and

hiking. Stabilization and enhancement of fresh and intermediate marsh should

enhance waterfowl hunting.

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g. Special Aquatic Sites.

The study area includes the 4,212-acre Mandalay National Wildlife Refuge

(NWR) which is an important stopping point for migratory birds. The habitat of

the NWR is mostly fresh marsh with access to the interior of the NWR limited to

boat travel. The NWR is visited annually more than two thousand times. The

most prominent recreational activities within the NWR include fishing and

waterfowl hunting. Limited consumptive recreation uses include recreational

crabbing, shrimping, and crawfishing. Natural ridges are also utilized for deer

and small game hunting. Non-consumptive recreational activities attract far

fewer participants and include wildlife observation, photography, and boating.

The NWR also provides opportunities for environmental education and

interpretation. The NWR is showing a slight increase in land area and no losses

of aquatic habitat. No direct impacts to the NWR are anticipated from

implementation of the proposed action.

The Louisiana coastal wetlands represent an ecosystem of national importance

from an environmental standpoint. Subsidence, lack of sediment and nutrient

deposition, erosion via tidal exchange, channelization, and saltwater intrusion

have resulted in the loss of several thousand acres of solid, vegetated marsh. In

general, the areas with the highest rates of land loss are the intermediate,

brackish, and saline marshes in the southern and eastern sections of the study

area. The swamp and fresh marsh habitats generally are exhibiting lower rates of

land loss and in some cases land gain. For future without project condition

determination, the current rate of land loss within each polygon was assumed to

continue on a linear trend over the 50-year period of analysis. Over the entire

study area, approximately 100,000 acres of marsh were projected to be lost

between 2015 and 2065. Direct wetland impacts associated with the RP would

result in 148 acres of swamp, 343 acres of fresh marsh, 248 acres of intermediate

marsh, and 182 acres of brackish marsh being directly converted to open water.

The RP would also result in 23 acres of swamp being converted to upland

(levee). These direct impacts would be the result of dredge features WD2, CD1,

CD3, CD6, ED2, ED3, ED6, and ED7 and levee features CLV1 and CLV2. The

RP would also create 257 acres of brackish marsh and 72 acres of saline marsh

as a result of features CM2, CM3, CM4, CT1, CT2, CT3, CT6, CT7, CT8, EM1,

and EM3. Implementation of the RP would contribute to reducing regional rates

of marsh soil loss by an estimated 9,655 acres over the 50-year period of

analysis.

(2) Effects on Life Stages of Aquatic Life and Other Wildlife Dependent on Aquatic

Ecosystems.

There are no long-term adverse effects associated with the discharge of fill on the

life stages of aquatic life and other wildlife dependent on aquatic ecosystems within

the project area. Impacts from dredging activities, disposals, and structural feature

construction would be minimized, through the implementation of SWPPPs and other

applicable BMPs. Impacts associated with soil compaction, rutting, rill, and gully

erosion at construction sites would be kept to a minimum by use of proper

construction techniques such as silt curtains, temporary vegetative cover during

construction, and regrading and permanent vegetation establishment at the end of

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construction. Upon project completion, the features are anticipated to yield positive

benefits to the aquatic environment as well as fish, wildlife, and plankton that

depend upon coastal marshes for shelter, nesting, feeding, roosting, cover, nursery,

and other life requirements to sustain them and maintain their existence. Therefore,

associated habitat to be created as part of the project will be beneficial to the lifecycles of plankton, fishes, shellfish, crustaceans, amphibians, reptiles, birds, and

mammals.

(3) Effects on Aquatic Ecosystem Diversity, Productivity and Stability.

Construction of the RP would result in short-term construction-related impacts

within parts of the project area and would include some disturbance of fish and

wildlife habitat. However, these impacts would be temporary and would occur only

during construction, and are not expected to alter the long-term productivity of the

natural environment.

The RP would assist in the long-term productivity of the northern Terrebonne

marshes ecological community by improving the water quantity, water quality, and

nutrients delivered to area marshes as well as reduce negative impacts of Gulf storm

events. This in turn would facilitate the growth and productivity of emergent marsh

habitat. The RP would also result in enhancing the long-term productivity of the

natural communities throughout the region. These long-term beneficial effects of the

RP would outweigh the minimal and mitigable short-term impacts to the

environment resulting primarily from project construction.

(4) Effects on Recreational, Aesthetic, and Economic Resources.

Continued wetland fragmentation and the eventual conversion to shallow open

water habitat would likely have negative consequences on a variety of recreational

resources in the project area. Beneficial impacts to recreational resources are

expected to ultimately outweigh the negative, temporary impacts due to project

construction. These projects will likely stabilize and potentially enhance

recreational resources and associated economic activity well into the future. The

ecosystem restoration benefits of the other ongoing and planned projects coupled

with this alternative will maximize benefit to the recreational resource with

increased habitat stabilization and enhancement for fish and wildlife resources.

The project features will not adversely affect aesthetics within the project area.

Visual resources in the study area would be improved through the enhanced and

stabilized marsh and stabilized natural ridges. In particular, the enhanced and

stabilized marsh and stabilized natural ridges may be beneficial to Mandalay

National Wildlife Refuge and Pointe au Chien Wildlife Management Area and along

the Southern portions of the Wetlands Cultural Scenic Byway. Restored, enhanced

and sustained marshes will increase opportunities for visual use which include

wildlife observation, environmental interpretation, and cultural awareness.

Reducing the rate of land loss in the project area is expected to provide numerous

benefits on economic resources. The economic resources and industry that would

reap benefits from the project include agricultural lands used for timer production,

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commercial fishing and oyster industry, navigation industry, as well as oil, gas, and

utility companies.

G. Appropriate and Practicable Steps Taken to Minimize Potential Adverse Impacts of

the Discharge on the Aquatic Ecosystem.

As stated in Section II. E. (7) of this evaluation, formulation of project plans and designs,

evaluation of alternative plans, and development of operational scenarios for the RP, have

all been conducted with the objective of minimizing potential negative impacts to the

aquatic ecosystem. Without further action, the project area would continue to lose

approximately 2,500 acres of land per year, most of which is marsh. With continued

deterioration of marshes, the area landward will be more prone to flood during storm

surges and hurricanes. Additionally, the marshes of the study area represent an

ecosystem of national importance from an environmental standpoint. Deterioration will

continue unless preventative measures are taken. Therefore, there are no unavoidable

adverse impacts as a result of the implementation of reasonable alternatives for this

project. Placement of material excavated for construction of project features was

designed in the context of beneficial use, to be used for marsh and ridge creation which

will directly benefit habitat for wildlife and fish in the immediate vicinity of construction.

Plans for operation of the diversion structures have been and will continue to be refined

to maximize the beneficial effects of delivery of fresh water, sediment and nutrients to

the project area while avoiding or minimizing potential negative consequences to

freshwater, brackish, and saline marshes, swamps, bayous, lakes, and canals. The RP will

decrease the rate of decline of the wetlands to ensure their ability to provide geomorphic

and hydrologic form and function for the 50-year period of analysis. Marsh habitat for

essential fish and wildlife species will be sustained, mimicking as closely as possible

conditions which occur naturally in the area.

IV. EVALUATION RESPONSIBILITY

A. Evaluation Prepared By:

B. Evaluation Review By:

The proposed plan for the Convey Atchafalaya River Water to Northern Terrebonne

Marshes And Multipurpose Operation of Houma Navigation Lock, Lafourche,

Terrebonne, St. Mary Parish, Louisiana, which incorporates sites for dredging,

excavation, disposal, and the placement of fill, complies with the requirement of

guidelines, and includes appropriate and practicable methods to minimize adverse effects

to the aquatic ecosystem.

Date:

Alvin B. Lee

Colonel, U.S. Army

District Commander

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APPENDIX E:

Consistency Determination

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Volume III

APPENDIX E:

CONSISTENCY DETERMINATION

Louisiana Coastal Use Guidelines

1.0 INTRODUCTION ............................................................................................................... 2

2.0 PURPOSE AND NEED FOR THE PROPOSED ACTION................................................ 2

3.0 DESCRIPTION OF THE PROPOSED ACTION ............................................................... 4

4.0 GUIDELINES APPLICABLE TO ALL USES................................................................. 13

5.0 GUIDELINES FOR LEVEES ........................................................................................... 15

6.0 GUIDELINES FOR LINEAR FACILITIES..................................................................... 15

7.0 GUIDELINES FOR DREDGED MATERIAL DEPOSITION......................................... 16

8.0 GUIDELINES FOR SHORELINE MODIFICATIONS ................................................... 16

9.0 GUIDELINES FOR SURFACE ALTERATIONS ........................................................... 16

10.0 GUIDELINES FOR HYDROLOGIC AND...................................................................... 17

11.0 GUIDELINES FOR DISPOSAL OF WASTES................................................................ 17

12.0 GUIDELINES FOR USES THAT RESULT IN THE ALTERATION ............................ 17

13.0 GUIDELINES FOR OIL, GAS, AND OTHER MINERAL ACTIVITIES ...................... 17

14.0 CONSISTENCY DETERMINATION.............................................................................. 18

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Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

April 26, 2010 Draft

1.0 INTRODUCTION

Section 307 of the Coastal Zone Management Act of 1972, 16 U.S.C. 1451 et. seq. requires that

"each federal agency conducting or supporting activities directly affecting the coastal zone shall

conduct or support those activities in a manner which is, to the maximum extent practicable,

consistent with approved state management programs." In accordance with Section 307, a

Consistency Determination has been prepared for the proposed conveyance of Atchafalaya River

water to the Northern Terrebonne Marshes. This project was identified as a Near-term Critical

Restoration Feature Recommended for Study and Future Congressional Authorization in the

Louisiana Coastal Area (LCA) Main Report dated January 21, 2005. The project is described in

detail in the draft Integrated Feasibility Study and Environmental Impact Statement, Convey

Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma

Navigation Lock. The proposed action is located mostly in Terrebonne Parish in southeast

Louisiana at the northern edge of the Gulf of Mexico (Figure 1). Coastal Use Guidelines were

written in order to implement the policies and goals of the Louisiana Coastal Resources Program

(LCRP), and serve as a set of performance standards for evaluating projects. Compliance with

the LCRP, and therefore, Section 307, requires compliance with applicable Coastal Use

Guidelines.

2.0 PURPOSE AND NEED FOR THE PROPOSED ACTION

The natural processes of subsidence, habitat switching, and erosion, combined with human

activities, have caused significant adverse impacts to the Northern Terrebonne Marshes,

including accelerated wetland loss and ecosystem degradation. Wetlands in the project area are

deteriorating for several reasons: 1) subsidence, 2) lack of sediment and nutrient deposition, 3)

erosion via tidal exchange, 4) channelization, and 5) saltwater intrusion. These activities have

resulted in the loss of several thousand acres of solid, vegetated marsh. Deterioration will

continue unless preventative measures are taken.

In the absence of supplemental fresh water from the Atchafalaya River, subsidence, sea-level

rise, wave erosion, and saltwater intrusion will continue to be problems. Protection and

enhancement of this area are dependent on providing a hydrologic regime that minimizes the

physiological stress to wetland vegetation from saltwater intrusion and tidal energy and is

conducive to the retention of locally provided fresh water and sediments. Several channels have

been dredged which cut through the natural ridges, increasing both drainage and tidal exchange

in the project area, exposing the soil to erosive forces.

The wetland communities within the northwestern portion of the Terrebonne Basin, including

those located both north and south of the Gulf Intracoastal Waterway (GIWW), have been, in

part, separated from the influence of the Atchafalaya River. Instead, the hydrology of these areas

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is influenced by a widely variable pattern of Atchafalaya River backwater effect, rainfall runoff

events, and marine processes. Major navigation channels in the subprovince are the Atchafalaya

River, Wax Lake Outlet, Houma Navigation Canal, GIWW, and Lower Atchafalaya River (south

of Morgan City). Each of these navigation channels introduces and/or compounds marine

influences in many of the interior coastal wetlands and water bodies within the subprovince.

Without action, the fresh water, intermediate, and brackish marshes in the northern and eastern

areas of the Terrebonne Basin would continue to deteriorate and disappear due to the combined

effects of subsidence, saltwater intrusion, and a lack of riverine influence. The flotant marshes

within the Penchant Basin, located in northwest Terrebonne Basin, would continue to deteriorate

due to excessive backwater flooding events from the Atchafalaya River. To the south, the

brackish marshes surrounding Lake Mechant would continue to deteriorate due to saltwater

intrusion and a lack of riverine influence.

The project will provide opportunities to naturalize the distribution of fresh water and deltaic

forming sedimentsincluding those necessary for the creation of sustainable marsh

communities, improve hydrologic distribution of fresh water, improve topographic diversity, and

reduce the negative impacts of Gulf storm events.

Fresh Water Supply  Re-introduction of fresh water supplies is an opportunity to restore

a degraded and impaired deltaic forming process. Furthermore, fresh water introduction

has the potential to balance the altered salinity regime, improve the viability of fresh

water marsh plant life and therefore restore fish and wildlife habitats.

Hydraulic Distribution  Human induced habitat fragmentation (canals) has resulted in a

degraded condition whereby the limited existing fresh water supplies are directed towards

Terrebonne Marshes and into the Gulf. Opportunities exist to improve the internal

distribution of fresh water to restore and improve the sustainability of fresh water marsh

habitats.

Sediment Supply and Distribution  The lack of marsh forming sediments from riverine

environments has accelerated the degradation of all marsh types. Opportunities exist to

re-introduce sediments from the Atchafalaya River and several bayous to use on site

sediments displaced by Gulf storm events to create new marsh area.

Sustainability  As marsh degradation has accelerated, seasonal Gulf events have a

magnified impact on the remaining marsh areas. Opportunities exist through fresh water

supply and distribution and sediment supply and distribution to create a healthier marsh

which will be more resistant to the normal range of Gulf events.

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Figure 1. Project vicinity for the project, Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock.

3.0 DESCRIPTION OF THE PROPOSED ACTION

The overall study area is located mostly in Terrebonne Parish in southeast Louisiana at the

northern edge of the Gulf of Mexico and encompasses approximately 1,100 square miles

(700,000 acres). A portion of Lafourche Parish between Bayou Lafourche and Bayou Pointe au

Chien is also included in the study area. Small portions of St. Mary, St. Martin, and Assumption

Parishes are also included. The study area is approximately 55 miles wide from west to east and

averages 20 miles across from the north to south boundaries.

For the purposes of this Consistency Determination, the study area has been divided into three

sub-areas: West-Bayou Penchant Area, Central-Lake Boudreaux Area, and East-Grand Bayou

Area (Figure 2). The study area lies within the Barataria-Terrebonne estuary. This estuary

extends from the west bank levees of the Mississippi River (north and east), to the East Guide

Levee of the Atchafalaya River (west), to the Gulf of Mexico (south), and to the town of

Morganza (north). The Barataria Basin covers about 1,551,800 acres while the Terrebonne

Basin covers an area of about 2,063,500 acres. The study area lies within the southern end of the

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Figure 2. Map of project area for Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock. Project subareas are shown.

Terrebonne Basin and contains a complex of habitat types, including natural levees, lakes,

swamps, marshes, and bayous formed from sediments of abandoned Mississippi River deltas.

Elevations in the study area vary. Near Houma, the largest city in the area, the elevation is

approximately 10 feet National Geodetic Vertical Datum (NGVD). The elevation along the

bayou ridges is 4-5 feet NGVD and less than 1 foot NGVD along the southern portion near the

Gulf of Mexico.

The major streams located in the study area or that influence the study area are the Atchafalaya

River, Bayou du Large, Bayou Grand Caillou, Bayou Petit Caillou, Bayou Terrebonne, Bayou

Pointe au Chien, Bayou Lafourche, Bayou Leau Blue, and Bayou Black. There are no scenic

streams in the study area designated under the Louisiana Natural and Scenic River System. The

Houma Navigation Canal runs north and south from the GIWW to the Gulf of Mexico mainly

between Bayou du Large and Bayou Grand Caillou. The GIWW follows an east-west path in the

northern portion of the study area. These two waterways, along with the natural channels in the

area, have a strong influence on surface water in the area.

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The proposed action involves construction of 57 structures and other water management features

(Figure 3), in an effort to holistically address the declining health of the Terrebonne Marshes

ecosystem. For this Consistency Determination, construction features (measures) are identified

using a sequence of letters. This labeling convention is described in Table1. A description of

each proposed construction feature, including the dimensions and purpose of each feature, is also

included in Table 1.

There are two proposed water diversion-type structures at critical points in the Terrebonne

Marshes: the Central Diversion Structure (CS1) involves constructing six 10' x 10' gated box

culverts on Bayou Butler under Highway 57 to increase fresh water movement from the HNC to

Bayou Grand Caillou/Lake Boudreaux; the Eastern Culvert #5 (EC5) is composed of a bridge

with five 83-foot spans with two 68.5-foot spans accommodating Highway 24. Associated with

this bridge are five 80-foot Obermeyer gated openings, for a total flow opening width of 400

feet. EC5 is intended to convey fresh water from the GIWW to Grand Bayou under Highway 24.

Other project measures in the western portion of the project area include: 51,802 feet of

dredging (WD2 and WD3), which would increase delivery of fresh water from Bayou Penchant

to southeast Penchant Basin marshes and eliminate a constriction in the GIWW; a soil plug (WP

1), which would be placed to retain fresher water in Bayou du Large and Lake Mechant and

prevent saltwater intrusion; a rock filled sheet pile weir with boat openings, which would

constrict Grand Pass by 90% to minimize water exchange between Bayou du Large and Caillou

Lake.

There are several project measures in the central project area in addition to the Central Diversion

Structure: a set of three measures (CC1, CC2, and CD4) which would increase water volume

moving past the GIWW constriction at the twin span bridge in Houma; several project measures

(CT1-8, CM2, CM3, CC3-15, CD1-2, 6, 7, CLV1, CLV2, and CP2) working in conjunction with

the Central Diversion Structure to deliver and retain fresh water and to prevent greater saltwater

intrusion into Lake Boudreaux; a 23,500 linear foot soil berm (CM4), which would be placed

perpendicular to tidal flow to retain fresh water in marshes to the north and prevent saltwater

intrusion from the south in the marshes to the west of the proposed HNC Lock; a soil plug

(CP2), which would be placed in a canal near Bayou Butler to prevent short circuiting of fresh

water through the N/S Gulf South Pipeline canal; the Central Lock Complex (CL1), which is the

proposed HNC Lock that will optimize the sector gates operation for environmental benefits by

keeping them closed more frequently. This would hold water back and move fresh water onto

central Terrebonne marshes. When the sector gates are closed boat traffic would travel through

the lock chambers. For vessels exceeding the lock size, an industry traffic management system

will be developed to opportunistically open the sector gates to let these vessels pass.

Project measures in the eastern portion of the project area and associated with the Eastern

Culvert #5 (EC5) include a soil berm, culverts and dredging. East Dredge Channel #5 (ED5) is a

1000-foot channel that would connect the GIWW to EC5. East Dredge Channel #3 (ED3) is a

16,500-foot expansion of Grand Bayou that would deliver fresh water into the Grand Bayou

Basin. ED7 is a 13,000-foot extension of ED3 further into the Grand Bayou Basin. Along

Grand Bayou at the point where ED3 becomes ED7, 5 5 x 5 box culverts (EC2) would convey

flow to the west through an existing levee along the alignment of the existing Grand Bayou,

which would be dredged (ED6) for a length of 16,800 feet to freshen Eastern Grand Bayou

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marshes. Related to this a 13,000 linear foot soil berm (EM1) would be placed perpendicular to

tidal flow to prevent saltwater intrusion into the Eastern Grand Bayou marshes. Below ED7 on

Grand Bayou ten 5 x 5 flap-gated box culverts with variable crest outfall (EC3) would be

installed to convey fresh water, prevent saltwater movement, and allow control of water levels in

marshes to the northwest. Further to the south another 37,000-foot linear soil berm (EM3) would

be placed perpendicular to tidal flow to slow fresh water movement to the Gulf and prevent

saltwater intrusion from the south in an effort to stabilize the marshes in the lower Grand Bayou

basin.

Additionally in the projects eastern area several measures would be taken to improve fresh

water conveyance from the GIWW down St. Louis Canal. Two 8'x8' 8-barrel flap-gated culverts

(EC6 and EC7) would allow water movement under roads that are currently constricting flow

into St. Louis Canal. Planned dredging of St. Louis Canal for 56,300 feet (ED2) would allow

water movement from the GIWW through EC6 and EC7 to the Grand Bayou basin. Removals of

a rock weir (EX1) and of a soil plug (EX2) would increase water movement through the basin to

better distribute fresh water from Grand Bayou and St. Louis Canal. Excavations of two gaps

(EG1 and EG2) in canal spoil banks would facilitate better fresh water movement in the

respective areas. A boat bay 20' wide with an invert of -5' (EP7) would be placed on Cutoff

Canal on the north bank of Bayou Pointe au Chien to retain fresh water in marshes to the north

and prevent saltwater intrusion from the south.

The proposed action would have an initial negative direct impact on existing wetland vegetation,

wildlife and fisheries resources, and essential fish habitat within the construction footprint. The

dredge features WD2, CD1, CD3, CD6, ED2, ED3, ED6, and ED7 and levee features CLV1 and

CLV2 (Table 2) would directly impact approximately 622 acres of shallow open water (Table 2).

In addition, construction of these features would result in approximately 148 acres of swamp,

343 acres of fresh marsh, 248 acres of intermediate marsh, and 182 acres of brackish marsh

being directly converted to open water (Table 2). The proposed action would also result in

approximately 23 acres of swamp being converted to uplands (levee).

The proposed action would also create approximately 257 acres of brackish marsh and 72 acres

of saline marsh as a result of features CM2, CM3, CM4, CT1, CT2, CT3, CT6, CT7, CT8, EM1,

and EM3. Additionally, the proposed action is expected to prevent approximately 9,655 acres of

emergent marsh from being converted to open water by year 50 after project implementation.

These wetlands will continue to provide nesting, rearing, and foraging habitat for resident and

migratory wildlife species. Preserved wetlands will also provide valuable foraging, breeding,

and nursery habitat, as well as other essential fish habitat, for finfish and shellfish in the project

area.

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Figure 3. Map of the project area and Recommended Plan, showing the 57 structures and water management features proposed forconstruction for the project. Construction features, and their labeling convention, are further described in Table 1.

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Table 1. List and description of construction features (measures) proposed for the project.

ID1 Measure Name Description Size/ Width2 Lgth2 Purpose

CL1 Central Lock Complex #1 Multi-purpose operation of proposed HNC4 Lock Complex N/A N/A Optimize operation of HNC lock for distribution of fresh water and prevention of saltwater intrusionEC5 East Culvert #5 Bridge construction with Obermeyer gates installed between the piers 80 x 20 552 Convey fresh water from GIWW5 to Grand Bayou under Hwy 24, same location as ES2EC23 East Culvert #2 Box culvert 5x5 26 Convey flow through existing levee from Grand Bayou to WEC33 East Culvert #3 Flap-gated box culverts w/variable crest outfall 5x5 75 Convey fresh water to the W through an existing levee and prevent saltwater movement from Grand Bayou to NWEC6 East Culvert #6 Flap gated box culverts 8x8 50 Allow water movement down St. Louis Canal under Hwy 24EC7 East Culvert #7 Flap gated box culverts 8x8 40 Allow water movement down St. Louis Canal under roadED2 East Dredge Channel #2 Canal dredging 50 56270 Allow water movement from GIWW5 through EC6 & 7 to Grand Bayou basinED63 East Dredge Channel #6 Dredge a portion of Grand Bayou 290 16818 Allow water movement to E Grand Bayou marshesED73 East Dredge Channel #7 Canal dredging 150 13081 Allow water movement further down Grand BayouEM1 East Marsh Berm #1 A linear soil berm placed perpendicular to flow 30 W 13000 To slow fresh water movement to the gulf; prevent saltwater intrusion from SEM3 East Marsh Berm #3 A linear soil berm placed perpendicular to flow 30 W 37000 To slow fresh water movement to the gulf; prevent saltwater intrusion from SEG13 East Spoil Gap #1 Gap in canal spoil bank 1.7 acres 750 Allow movement of fresh water from unnamed canal to marshes to the S/SWEG23 East Spoil Gap #2 Gap in canal spoil bank 0.5 acres 400 Allow movement of fresh water from unnamed canal to marshes to the EEP7 East Plug #7 Boat bay on Cutoff Canal at junction with Point au Chien 20 360 To retain fresh water to N; prevent saltwater from SEX13 East Removal #1 Rock weir removal 50 W 100 Increase water movement through canal - distribute fresh water from Grand BayouEX23 East Removal #2 Soil plug removal 50 W 130 Increase water movement through canal - distribute fresh water from Grand Bayou/St. Louis CanalCC3 Central Culvert #3 Gated control structure 10x10 175 Increase fresh water delivery from HNC4 through Bayou Provost to Bayou Grand Caillou/Lake BoudreauxCC4 Central Culvert #4 Gated control structure 10x10 175 Increase fresh water movement from HNC4 to Bayou Grand Caillou/Lake BoudreauxCC53 Central Culvert #5 Aluminum flap-gated culvert 4x4 48 Convey fresh water from N to S into N Lake Boudreaux systemCC63 Central Culvert #6 Aluminum flap-gated culvert 4x4 48 Convey fresh water from N to S into N Lake Boudreaux systemCC73 Central Culvert #7 Aluminum flap-gated culvert 4x4 48 Convey fresh water from N to S into N Lake Boudreaux systemCC83 Central Culvert #8 Aluminum flap-gated culvert 4x4 48 Convey fresh water from N to S into N Lake Boudreaux system

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ID1 Measure Name Description Size/ Width2 Lgth2 Purpose

CC93 Central Culvert #9 Aluminum flap-gated culvert 4x4 40 Convey fresh water from N to S into N Lake Boudreaux systemCC103 Central Culvert #10 Aluminum flap-gated culvert 4x4 40 Convey fresh water from N to S into N Lake Boudreaux systemCC113 Central Culvert #11 Aluminum flap-gated culvert 4x4 40 Convey fresh water movement from N to S into N Lake Boudreaux systemCC123 Central Culvert #12 Aluminum flap-gated culvert 4x4 40 Convey fresh water movement from N to S into N Lake Boudreaux systemCC133 Central Culvert #13 Box culverts with sluice gates under Hwy 57 10x10 175 Increase fresh water movement from HNC4/Bayou Grand Caillou to N Lake BoudreauxCC143 Central Culvert #14 Flap-gates each with a stop log bay 4x4 45 Convey fresh water from new channel to N marshesCC153 Central Culvert #15 Timber weir placed at 90 to flow with boat openings 68 W N/A Prevent short circuiting of fresh water through the N/S Gulf S Pipeline canalCD1 Central Dredge Channel #1 Dredge Bayou Provost 70 W 5,691 Increase fresh water delivery from HNC4 through CC3 to Bayou Grand Caillou/Lake BoudreauxCD2 Central Dredge Channel #2 Dredge part of Bayou Butler 45 W 1000 Increase fresh water movement from HNC4 through CS1 to Bayou Grand Caillou/Lake BoudreauxCD3 Central Dredge Channel #3 Dredge Falgout Canal 70 W 4426 Increase fresh water movement from HNC4 through CC4 to Bayou Grand Caillou/Lake BoudreauxCD63 Central Dredge Channel #6 Dredge new water conveyance channel 45 W 7014 Convey fresh water from Bayou Pelton enlargement through CC14 to N Lake Boudreaux marshesCD73 Central Dredge Channel #7 Dredge Bayou Pelton to enlarge it 70 W 6416 Increase fresh water movement from HNC4 through CC13 to Bayou Grand Caillou/N Lake BoudreauxCLV13 Central Levee #1 New forced drainage levee +8 H 5173 Prevent potential flooding from proposed increase in flows to N Lake BoudreauxCLV23 Central Levee #2 New forced drainage levee +8 H 1760 Prevent potential flooding from proposed increase in flows to N Lake BoudreauxCM2 Central Marsh Berm #2 A linear soil berm placed perpendicular to flow 30 W 11255 Retain fresh water in Lake Boudreaux and marshes to N; prevent saltwater intrusion from SCM3 Central Marsh Berm #3 A linear soil berm placed perpendicular to flow 30 W 8975 Retain fresh water in Lake Boudreaux and marshes to N; prevent saltwater intrusion from SCM4 Central Marsh Berm #4 A linear soil berm placed perpendicular to flow 30 W 23458 Retain fresh water in marshes to N; prevent saltwater intrusion from SCP1 Central Plug #1 Soil plug in Robinson Canal 175 W 25 Retain fresh water in Lake Boudreaux basin; prevent saltwater intrusion from Bayou Petit CaillouCP23 Central Plug #2 Soil plug in canal near Bayou Butler 60 W 25 Prevent short circuiting of fresh water through the N/S Gulf S Pipeline canalCS1 Central Diversion Structure #1 Sluice gated box culverts on Bayou Butler under Hwy 57 10x10 100 Increase fresh water movement from HNC4 to Bayou Grand Caillou/Lake BoudreauxCT13 Central Terracing #1 A grid of 10 wide berms perpendicular to surge 359 acres N/A Retain fresh water and prevent saltwater intrusion

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ID1 Measure Name Description Size/ Width2 Lgth2 Purpose

CT23 Central Terracing #2 A grid of 10 wide berms perpendicular to surge 40 acres N/A Retain fresh water and prevent saltwater intrusionCT33 Central Terracing #3 A grid of 10 wide berms perpendicular to surge 109 acres N/A Retain fresh water and prevent saltwater intrusionCT63 Central Terracing #6 A grid of 10 wide berms perpendicular to surge 71 acres N/A Retain fresh water and prevent saltwater intrusionCT73 Central Terracing #7 A grid of 10 wide berms perpendicular to surge 83 acres N/A Retain fresh water and prevent saltwater intrusionCT83 Central Terracing #8 A grid of 10 wide berms perpendicular to surge 156 acres N/A Retain fresh water and prevent saltwater intrusionWD2 West Dredge Channel #2 Dredge a part of Carencro Bayou and create new canal 200 35463 Increase delivery of fresh water from Bayou Penchant to SE Penchant Basin marshesWD3 West Dredge Channel #3 Dredge a portion of GIWW5 50 16339 Eliminate constriction in GIWW5WP1 West Plug #1 Soil plug 20 115 Retain fresher water in Bayou du Large and Lake Mechant and prevent saltwater intrusionWW23 West Weir #2 Rock filled sheet pile weir with boat openings 940 W 100 Constrict Grand Pass by 90% to minimize water exchange between Bayou du Large and Caillou LakeED33 East Dredge Channel #3 Canal dredging 470 16483 Convey fresh water from GIWW5 to Grand Bayou basinCD4 Central Dredge Channel #4 Dredge a new secondary channel along the GIWW at Hwy 24 bridges 70 1852 Increase water volume moving past GIWW5constrictionED5 East Dredge Channel #5 Dredge new canal 470 1000 Convey fresh water from GIWW5 through ES2 or EC5 to Grand BayouCC1 Central Culvert #1 Box culvert in CD4 channel under Hwy 24 bridge 10x10 115 Increase water volume moving past GIWW5constrictionCC2 Central Culvert #2 Box culvert in the CD4 channel under Hwy 24 bridge 10x10 115 Increase water volume moving past GIWW5constriction

1 Measure ID  Measures are identified by a unique sequence such as EC5. The first letter describes the subunit location: W = Bayou Penchant, C = Lake Boudreaux, and E = Grand Bayou. The second

and third letters describe the type of measure: C = culvert, D = dredge, M & MC = marsh creation, X = removal, S = structure, L = lock, G = gap, P = plug, LV = levee, T = terracing, O = shorelineprotection and W = weir. The number provides a unique ID for that particular type of measure in that subunit. In some cases, measures were redesigned but the ID was retained. 2 All measurements are approximate. Unless otherwise noted, all measurements are in feet.

3 Measures in bold were proposed as part of a Coastal Wetlands Planning, Protection, and Restoration Act project. 4 HNC  Houma Navigation Canal 5 GIWW  Gulf Intracoastal Waterway

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Table 2. Projected disturbance area by habitat type for construction features impacting the project area.

Feature

ID Feature Name Wetland Type

Wetland

Disturbance

(length x width)

Wetland Disturbance

Area (acres)

Existing

Channel

Width (feet)

Open Water

DisturbanceArea (acres)

ED2 East Dredge Channel #2 Swamp/Wetland Forest 18,720 x 230 98.8 50.0 21.5ED2 East Dredge Channel #2 Intermediate Marsh 21,600 x 230 114.0 50.0 24.8ED2 East Dredge Channel #2 Brackish Marsh 7,680 x 230 40.5 50.0 8.8ED3 East Dredge Channel #3 Intermediate Marsh 10,363 x 505 120.0 225.0 53.5ED3 East Dredge Channel #3 Swamp/Wetland Forest 1,604 x 560 20.6 170.0 6.3ED3 East Dredge Channel #3 Brackish Marsh 4,477 x 455 46.8 275.0 28.3ED6 East Dredge Channel #6 Brackish Marsh 17,000 x 190 74.0 360.0 140.5ED7 East Dredge Channel #7 Brackish Marsh 13,000 x 70 20.9 330.0 98.5

CD1 Central Dredge Channel #1 Intermediate Marsh 3,383 x 70 5.4 210.0 16.3CD1 Central Dredge Channel #1 Swamp/Wetland Forest 1,602 x 70 2.6 210.0 7.7CD3 Central Dredge Channel #3 Intermediate Marsh 3,700 x 100 8.5 120.0 10.2CD6 Central Dredge Channel #3 Swamp/Wetland Forest 2,587 x 290 17.2 N/A 0.0CD6 Central Dredge Channel #3 Fresh Marsh 3,562 x 290 23.7 N/A 0.0CD7 Central Dredge Channel #7 Swamp/Wetland Forest 5,387 x 260 9.2 60.0 7.4

CLV1 Central Levee #1 Swamp/Wetland Forest N/A 18.4 N/A 0.0CLV2 Central Levee #2 Swamp/Wetland Forest N/A 4.4 N/A 0.0

WD2 West Dredge Channel #2 Fresh Marsh 2,471 x 290 16.4 140.0 7.9WD2 West Dredge Channel #2 Fresh Marsh 27,063 x 430 267.1 N/A 0.0WD2 West Dredge Channel #2 Fresh Marsh 5,766 x 269 35.6 161.0 21.3WD3 West Dredge Channel #3 Swamp/Wetland Forest 16,500 x 205 0.0 445.0 168.6

Total 9441 622

1 converted to open water with the exception of 23 acres converted to uplands (levee)

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4.0 GUIDELINES APPLICABLE TO ALL USES

These guidelines are acknowledged and have been addressed through the preparation of

responses to the guidelines contained within the specific use categories.

Guidelines 1.1  1.6: The guidelines have been read in their entirety, and all applicable

guidelines would be complied with. The proposed project would be in conformance with all

applicable water and air quality laws, standards and regulations, and with those other laws,

standards and regulations which have been incorporated into LCRP, and is deemed in

conformance with the program except to the extent that these guidelines would impose additional

requirements. The proposed activity shall not be carried out or conducted in such a manner as to

constitute a violation of the terms of a grant or donation of any lands or water-bottoms to the

State or any subdivision thereof. Information regarding potential impacts of the proposed action

is provided herein and in the accompanying feasibility study and environmental impact statement.

Guideline 1.7: Potential short- and long-term effects resulting from the proposed project include

increased total suspended sediments, turbidity, and organic/nutrient enrichment of the water

column; disturbance and release of possible contaminants; decrease in water temperatures; and

the possible release of oxygen depleting substances as well as possibly increasing dissolved

oxygen levels. Potential impacts would be minimized, as much as practicable, through the

implementation of stormwater pollution prevention plans (SWPPPs) and other applicable best

management practices (BMPs). Impacts associated with soil compaction, rutting, rill, and gully

erosion at construction sites would be kept to a minimum by use of proper construction

techniques such as silt curtains, temporary vegetative cover during construction, and regrading

and permanent vegetation establishment at the end of construction.

Generally, four water quality conditions could change with implementation of the proposed

project:

1) Fresh water would be moved throughout the entire project area;

2) Salinities would decrease throughout most of the project area;

3) Sediments in the project area would increase allowing for marsh nourishment and marsh

platform development, along with accompanying minor increases in trace metals associated

with bed sediments; and

4) Nutrients in the project area could increase.

Introduction of river water into the Terrebonne Basin would immediately change the water

chemistry of receiving areas. Change may be beneficial or detrimental, depending on human

perceptions and the water uses. The change from a less fresh to a fresher system could be

perceived as beneficial to wetland nourishment, but detrimental to recreational use because of

water color changes, and possible changes in fish species assemblages in the recreational area.

However, the changes in water chemistry would mimic natural conditions prior to the Northern

Terrebonne Marshes partial separation from the influence of the Atchafalaya River.

Stabilization of salinity regimes would probably aid resource managers, commercial and

recreational fisheries managers, and water users in making long-term decisions. Salinity could

be either beneficial or detrimental, depending on the user group. Salinity is not necessarily a

pollutant in coastal waters. Fresh water marshes, however, are sensitive to salinity levels, but the

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varying levels of salinity have positive impacts on various commercial and recreational fisheries.

On balance, the stabilization of salinities, or the relocation of saltier water zones gulfward, would

help to achieve the goals of the proposed project. The reintroduction of streambed sediments

into the project area may add some contaminants; these could include primarily trace metals and

hydrophobic organic compounds from the Atchafalaya and Mississippi Rivers streambed

sediments.

Cumulative impacts to water quality would primarily be related to the incremental impact of all

past, present, and future actions affecting water quality within the Basin such as: increase in

fresh water areas; stabilization or decrease in salinities; increase in sediment introduction to the

coastal zone, with accompanying minor increases in trace metals associated with bed sediments;

increased total suspended sediments; increased turbidity; increased organic/nutrient enrichment

of the water column; disturbance and release of possible contaminants; decrease in water

temperatures along with fewer water temperature fluctuations; and increased dissolved oxygen

levels. However, the cumulative impacts to the water quality of the Terrebonne Basin resulting

from this project would be a synergistic positive result over and above the additive combination

of impacts and benefits of the other alternatives.

Any increases in suspended solids and turbidity levels due to dredging related activities in the

immediate project area would be minor, temporary, and highly localized.

No adverse alteration or destruction of unique or valuable habitats, critical habitat for endangered

species, important wildlife or fishery breeding or nursery areas, designated wildlife management

or sanctuary areas, or forestlands is anticipated. No adverse cumulative or secondary impacts to

the biological productivity of wetland ecosystems are anticipated. Adverse disruptions of coastal

wildlife and fishery migratory patterns are not anticipated.

No adverse alteration or destruction of public parks, shoreline access points, public works,

designated recreation areas, scenic rivers, or other areas of public use and concern is anticipated.

No increases in the potential for flood, hurricane or other storm damage, or increases in the

likelihood that damage will occur from such hazards are anticipated.

No significant economic impacts on the locality or adverse disruptions of existing social patterns

would occur due to the proposed action. No cultural, historical, or recreational resource sites

would be impacted by construction. No proximal areas of special concern exist. No land loss,

erosion, or subsidence would occur. This project would not result in reduced long-term

biological productivity of the coastal ecosystem.

Guidelines 1.8  1.10: Acknowledged. Perceived adverse impacts listed above would clearly be

outweighed by the human and environmental benefits the proposed project would provide

through the naturalization of the distribution of fresh water and deltaic forming sediments

including those necessary for the nourishment and creation of sustainable marsh communities,

improvements to hydrologic distribution of fresh water, improvements to topographic diversity,

reduction in negative impacts of Gulf storm events, and the inhibition of invasive species in the

Northern Terrebonne Marshes and the Terrebonne Basin.

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5.0 GUIDELINES FOR LEVEES

Guidelines 2.1  2.6: Acknowledged. Approximately 5173 and 1760 linear feet of levee will be

constructed for CLV1 and CLV2 features, respectively. Construction of these forced drainage

levees would directly impact 23 acres of swamp through conversion to upland habitat. The

proposed levees would prevent potential flooding from proposed increases in flows to Lake

Boudreaux. A 23,500 linear foot soil berm (CM4) would be placed perpendicular to tidal flow to

retain fresh water in marshes to the north and to prevent saltwater intrusion from the south. Two

additional soil berms (CM2 and CM3) encompassing 20,230 linear feet would retain fresh water

in Lake Boudreaux and marshes to the north while preventing saltwater intrusion from the south.

The remaining two soil berms (EM1 and EM3) would be constructed to slow the movement of

fresh water gulfward while preventing saltwater intrusion from the south.

6.0 GUIDELINES FOR LINEAR FACILITIES

Guidelines 3.1  3.8: Acknowledged.

Guideline 3.9: The proposed dredge channels excavated for increased fresh water conveyance

would improve natural hydrologic and sediment transport patterns, sheet flow, and water quality,

and will positively benefit the receiving wetlands and associated fish and wildlife habitat in the

project area and elsewhere in the Terrebonne Basin.

Guideline 3.10

The Central Lock Complex (CL1) would optimize operation of the proposed Houma Navigation

Canal (HNC) Lock Complex for improved distribution of fresh water and prevention of saltwater

intrusion.

: Linear facilities shall be planned, designed, and built using the best practical

techniques to prevent bank slumping and erosion, saltwater intrusion, and to minimize the

potential for inland movement of storm-generated surges. Consideration shall be given to the

use of locks in navigation canals and channels which connect more saline areas with fresher

areas.

Guideline 3.11: Soil plugs would be utilized in Cutoff Canal (EP7), in an opening near Bayou

du Large (WP1), Robinson Canal (CP1), and in a canal near Bayou Butler (CP2). EP7 would be

placed in Cutoff Canal on the north bank of Bayou Pointe au Chien to retain fresh water in

marshes to the north while preventing saltwater intrusion from the south. WP1 would be placed

to retain fresh water in Bayou du Large and Lake Mechant and prevent saltwater intrusion. CP1

would help to retain fresh water in the Lake Boudreaux basin and prevent saltwater intrusion

from Bayou Petite Caillou. CP2 would prevent short circuiting of fresh water through the N/S

Gulf South Pipeline canal. All plugs would be properly maintained.

Guideline 3.12: Where possible, dredge channels excavated for increased fresh water

conveyance will utilize currently existing canals, which will reduce the length of newly

constructed linear channel needed for the project and minimize adverse impacts to wetlands

associated with channel excavation.

Guidelines 3.13  3.16: Acknowledged.

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7.0 GUIDELINES FOR DREDGED MATERIAL DEPOSITION

Guideline 4.1: Several channels (both new and existing) are proposed for dredging in the project

area (Table 1). Dredged materials removed during excavation and enlargement of conveyance

channels would be deposited in a manner that would avoid disruptions of water movement, flow,

circulation and quality. Dredged material deposition is not expected to result in significant or

persistent water quality impacts in the vicinity of construction activities. Any minor increases in

suspended sediment and turbidity levels during dredged material deposition would be temporary

and highly localized. Minor reductions in dissolved oxygen levels associated with dredged

material deposition would be temporary.

Guideline 4.2: Acknowledged. Dredged material shall be used beneficially to the maximum

extent practicable to improve productivity or create new habitat, reduce or compensate for

environmental damage done by dredging activities, or prevent environmental damage. Dredged

materials would be used to create 43,688 linear feet of marsh berm, which will help to create

approximately 329 acres of marsh platform, retain fresh water in Lake Boudreaux and adjacent

marshes, and prevent salt water intrusion from the south. Dredged materials would be used in

the construction of approximately 23 acres of uplands, which would help to prevent potential

flooding from proposed increase in flows to north Lake Boudreaux, while providing new ridge

habitat for wildlife.

Guideline 4.3: Dredged materials will not be disposed of in a manner which could result in the

impounding or draining of wetlands or the creation of development sites.

Guidelines 4.4 - 4.6: Acknowledged.

Guideline 4.7: Not applicable.

8.0 GUIDELINES FOR SHORELINE MODIFICATIONS

Guidelines 5.1  5.4: Acknowledged. Shoreline modifications in the proposed project area will

result from construction of several in-water culvert features, including gated openings associated

with bridge construction (Table 1).

Guidelines 5.5  5.9: Not Applicable.

9.0 GUIDELINES FOR SURFACE ALTERATIONS

Guidelines 6.1  6.5: Acknowledged. Surface alterations in the proposed projects construction

footprint will mainly entail the construction of culverts, excavation of new channels and old spoil

bank gaps, enlargement of existing channels for improved conveyance, and placement of

excavated material for the creation of new construction features, such as levees and marsh berms

(Table 1).

Guideline 6.6: Acknowledged. Areas modified by surface alteration activities would, where

applicable, be regraded and revegetated upon termination of the use.

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Guidelines 6.7 - 6.13: Potential impacts associated with surface alteration sites would be

minimized, as much as practicable, through the implementation of stormwater pollution

prevention plans (SWPPPs) and other applicable best management practices (BMPs). Impacts

associated with soil compaction, rutting, rill, and gully erosion at surface alteration construction

sites would be kept to a minimum by use of proper construction techniques such as silt curtains,

temporary vegetative cover during construction, and regrading and permanent vegetation

establishment at the end of construction. The occurrence of low dissolved oxygen conditions in

the proposed project area waters would be temporary and minor. No heavy metal traps would be

created.

Guideline 6.14: Fill materials used in the construction of levees (CLV1 and CLV2) and marsh

berms (CM2-4) for the proposed action would be, to the maximum extent practicable, free of

known contaminants and compatible with the environmental setting.

10.0 GUIDELINES FOR HYDROLOGIC AND SEDIMENT TRANSPORT

MODIFICATIONS

Guidelines 7.1-7.9: Acknowledged. Numerous construction features (e.g., operation of

proposed HNC lock complex, conveyance channels, plug removal and construction, terracing,

spoil gaps, weir removal and construction, Obermeyer gates, berms, and culverts) (Table 1)

associated with the proposed action would modify hydrologic and sediment transport processes.

The proposed project is designed to introduce and/or divert fresh water to control salinities.

Construction of the proposed structures and other water management features would also convey

sediment and nutrients to the Northern Terrebonne Marshes and elsewhere in the Terrebonne

Basin to enhance fish and wildlife habitat and productivity, and offset land loss.

11.0 GUIDELINES FOR DISPOSAL OF WASTES

Guidelines 8.1  8.9: The proposed action would not involve the disposal of wastes; therefore,

these guidelines are not applicable.

12.0 GUIDELINES FOR USES THAT RESULT IN THE ALTERATION OF WATERS

DRAINING INTO COASTAL WATERS

Guideline 9.1: The proposed action will minimally affect water quality and flows in the

Atchafalaya River, while providing benefits to the environment of the Terrebonne Basin through

the diversion of fresh water, sediments, and nutrient inputs that should enhance fish and wildlife

habitat and productivity, and reduce land loss.

Guidelines 9.2 - 9.3: Not applicable.

13.0 GUIDELINES FOR OIL, GAS, AND OTHER MINERAL ACTIVITIES

Guidelines 10.1  10.14: The proposed action would not involve oil, gas, and other mineral

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activities; therefore, these guidelines are not applicable.

14.0 CONSISTENCY DETERMINATION

The proposed conveyance of Atchafalaya River water to the Northern Terrebonne Marshes will

provide additional fresh water, nutrients, and fine sediments to the Barataria-Terrebonne estuary

in southeast Louisiana. The proposed action will restore and maintain ecological integrity,

including habitats, communities, and populations of native species, and the processes that sustain

them by reversing the trend of degradation and deterioration in the project area, so as to

contribute towards achieving and sustaining a larger coastal ecosystem that can support and

protect the environment, economy, and culture of southern Louisiana and thus contribute to the

economy and well-being of the Nation. Based on this evaluation, the U. S. Army Corps of

Engineers, New Orleans District, has determined that the proposed action is consistent, to the

maximum extent practicable, with the State of Louisiana's Coastal Resources Program.

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APPENDIX F:

Cultural Resources Appendix

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Volume III

APPENDIX F:

Cultural Resources

Assessment of the Potential Effects on Archaeological Resources within

the LCA ARNTM Project Area

Prepared by

U.S. Army Engineer District St. Louis

Center of Expertise for Curation and Management

of Archaeological Collections (CX-CMAC)

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Table of Contents

1.1 Introduction.............................................................................................................. 4

2.1 Consultations............................................................................................................ 7

3.1 Physiographic Setting .............................................................................................. 8

4.1 Geomorphic History................................................................................................. 8

5.1 National Register of Historic Places ...................................................................... 10

6.1 Known Archaeological Surveys ............................................................................ 12

7.1 Project Area Reconnaissance................................................................................. 13

8.1 Site Population....................................................................................................... 14

9.1 Site Cultural/Temporal Affiliation......................................................................... 15

10.1 Site Locations......................................................................................................... 17

11.1 Site Landform Associations as listed on Site Record Forms................................. 18

12.1 Site Regional Landform Associations ................................................................... 18

13.1 Potential Disturbance from Project Features ......................................................... 25

14.1 Known Sites Endangered by Project Features ....................................................... 27

15.1 Testing Strategies................................................................................................... 30

16.1 Summary................................................................................................................ 31

17.1 References Cited .................................................................................................... 32

18.1 Addendum: Gagne Private Cemetery .................................................................... 33

19.1 Background............................................................................................................ 33

20.1 History of Cemetery Location ............................................................................... 34

21.1 Brief history of the Gagne Brothers....................................................................... 39

22.1 Summary and Conclusion...................................................................................... 40

23.1 References Cited .................................................................................................... 42

List of Figures

Figure 1. Physiographic sections along the lower Mississippi .......................................... 8

Figure 2. Historic delta sequence (after Weinstein and Gagliano 1985: Fig. 1)................ 9

Figure 3. Map of proposed project area displaying listed National Register locations ... 11

Figure 4. Map of proposed project area with known archaeological surveys and sites... 13

Figure 5. Map of routes taken by investigators during project reconnaissance............... 14

Figure 6. Chart showing chronology of cultural periods and number of sites within

project area so designated (in circle) ................................................................................ 17

Figure 7. Major site clusters within project boundary ..................................................... 18

Figure 8. Geologic map of proposed project area with known archaeological sites ....... 20

Figure 9. 1895 map of proposed project area showing known archaeological sites........ 24

Figure 10. Sites within 100 meters of proposed project features..................................... 28

Addendum

Figure 1. Current parcel lots in Houma, LA .................................................................... 33

Figure 2. Original land patents in Terrebonne Parish from 1830 survey......................... 34

Figure 3. Sketch map from Wesley House NRHP nomination ....................................... 36

Figure 4. 1924 Sanborn map of area near cemetery with modern shoreline indicated.... 37

Figure 5. 1940 Sanborn map of area near cemetery with modern shoreline indicated.... 37

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Figure 6. Land segments annexed to Houma................................................................... 38

List of Tables

Table 1. NR listed properties within project boundary.................................................... 10

Table 2. NR listed properties within one kilometers of project area ............................... 10

Table 3. Metrics of archaeological surveys within project boundary.............................. 12

Table 4. NRHP status for sites within project boundary ................................................. 15

Table 5. Cultural/temporal affiliation of sites within project boundary .......................... 15

Table 6. Landform listed on State Site Record Forms..................................................... 18

Table 7. Non-random distribution of sites verses geography of project area .................. 21

Table 8. Non-random distribution of sites verses geography of project area (single marsh

category) ........................................................................................................................... 21

Table 9. Non-random distribution of survey tracks vs. geography of project area ......... 22

Table 10. Non-random distribution of sites vs. geography of linear survey area (proxy for

bias)................................................................................................................................... 22

Table 11. Non-random distribution of sites vs. geography of linear survey area (proxy for

survey bias) with single marsh category........................................................................... 22

Table 12. Non-random distribution of sites verses geography of project area from 1895

map.................................................................................................................................... 23

Table 13. Temporary ROW of project features ............................................................... 25

Table 14. Impacted geologic regions of combined project features ................................ 26

Table 15. Archaeological sites within 100 meters of proposed project features ............. 30

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1.1 Introduction

In satisfaction of Section 106 of the NHPA, a Programmatic Agreement (PA) between

USACE-MVN, SHPO, and ACHP, has been developed to address the needs of LCA

projects including Convey Atchafalaya River Water to North Terrebonne Marshes. A

copy of the PA appears at the conclusion of this section. Federally recognized tribes,

State tribes, local governments and other interested parties have been invited to

participate as consulting parties. Copies of notification documents and lists of interested

parties follow the Programmatic Agreement at the end of the cultural resources summary.

The cultural resources portion of this feasibility study provides a synthesis of previous

investigations in the project area that includes the locations and available information for

surveys and sites reported, thus facilitating the expeditious planning and implementation

of the resulting project. The primary purpose of cultural resources identification is to

provide recommendations that will assist project managers, engineers, and other decisionmakers in the avoidance of adverse impacts. The current feasibility study is limited to

literature and records review and sample survey as set forth in ER 1105-2-100 paragraph

5 (Feasibility Phase Studies). There has been no evaluation and testing, intensive

survey/inventory, or mitigation.

Discovery of cultural resources and determinations of significance presented in this

section are drawn from archaeological survey reports and site recording documents

housed at the State Historic Preservation Office (SHPO) in Baton Rouge, Louisiana.

Both SHPO and THPO notification was undertaken to prepare concerned parties for

future project possibilities (see correspondence section below). Regular meetings with

SHPO and the Louisiana State Archaeologist were supplemented by email

correspondence in an effort to work in concert with the interests of the State and its

citizens. Visits to potentially impacted loci within the project area were undertaken over

two days on May 6, 2009 and May 7, 2009.

The standard for site significance adheres to the criteria established by the National

Register of Historic Places (NRHP) and outlined within 36 CFR 60.4. The standard for

significance as it applies to archaeological sites includes 1) sites that possess integrity

of location, design, setting, materials, workmanship, feeling, and association,

2) sites that are associated with events that have made a significant contribution to the

broad patterns of our history, 3) sites that are associated with the lives of persons

significant in our past, 4) sites that embody the distinctive characteristics of a type,

period, or method of construction, or represent the work of a master, possess high

artistic values, or represent a significant and distinguishable entity whose components

may lack individual distinction, or 5) sites that have yielded, or may be likely to yield,

information important to prehistory, or history.

The study area comprises approximately 1100 square miles, or 700,000 acres, that

includes four primary geologic regions. The full array of 61 project features have a total

temporary right of way of approximately 3497 acres. This represents the area of direct

impact. However, the intent of this project is to deliver fresh water in quantities such that

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the broader area of impact has yet to be determined. As such, the total area of potential

effect (APE) cannot be mapped at this time. In discussions with the Louisiana State

Archaeologist, a monitoring plan that would record long-term impacts to cultural

resources has been proposed and is included in the protocols to the Programmatic

Agreement.

The historic properties aspect of this feasibility study has the dual objective of identifying

cultural resources and site variability within the diverse biomes of the coastal Louisiana

marshes. The wetlands and natural levees comprise seven biotic communities that

sustained over four-hundred-fifty readily identifiable plant and animal species, providing

a vast resource base for human subsistence. Underlying these biotic communities are the

depositional environments that comprise the geomorphic history of the Terrebonne

Marshes project area. Depositional environments include fluvial features, such as the

natural levees, marshes, inland swamps, and lakes that support the distinctive biotic

communities previously mentioned. These features can be identified from maps and

remote imagery, from their distinctive lithological composition, and via various dating

techniques including radiocarbon (14C) and thermoluminescence (TL). Understanding

the relationship between sites and landforms helps archaeologists to both develop

probabilistic models and locate cultural resources. The effort for this study has been to

develop such a model for current and future planning.

Biological and environmental diversity in the coastal Louisiana marshes has supported

nomadic and settled subsistence regimes for human populations dating to at least 1000

B.C. Abundant archaeological evidence indicates a settlement pattern concentrated on

stable landscape features such as the natural levees flanking bayous, both active and

inactive, in the study area. To date, approximately three hundred archaeological sites

have been identified in the Terrebonne marshes and along the lobes of the LafourcheTerrebonne Delta. Given the nature of the terrain it is supposed that many Native

American traditional cultural properties, and or sacred sites have not been recorded. In

some cases, these areas cannot be identified without the assistance of the tribes. Thus, we

have requested tribal assistance in identifying such areas within the project boundaries.

The recoverable settlement history for the Terrebonne marshes appears to be tied to the

deposition and subsequent stabilization of the Lafourche-Terrebonne Delta between 2000

and 0 B.C. Relict beaches and channels of the delta provided early human foragers with

locations to which they returned in seasonal rounds of hunting and collecting. Repeated

use of these places is attested by deposits of shells from the bivalve Rangia cuneata, a

brackish-water clam. These shell deposits, or middens, contain both faunal and human

remains and culturally produced artifacts including pottery, which is used to tie

occupations at these sites to a relative chronology that is supported by radiocarbon (14C)

assay from other archaeological sites. Lenses of sediment frequently appear interspersed

within layers of shell, attesting to episodic overbanking along levees, and artifacts

indicate that sites may have been abandoned for extended periods, possibly due to

elevated water levels. The density of settlements associated with different periods of

occupation along Bayous Boeuf, Black, Shaffer, Chene, Mauvais Bois, De Cade, Du

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Large, Terrebonne, and Bayou Pointe au Chien, all natural levee landforms with sites

dispersed at several hundred meter intervals, may reflect a shifting settlement system in

response to this variable water table.

Significant sites were visited repeatedly and many habitation loci that were clearly

established in prehistory continued to be utilized through the post-bellum period.

Settlements in the Terrebonne marshes have been dated to major cultural periods from

the pre-ceramic Poverty Point (2000-500 B.C.) through Tchula-Tchefuncte (500-0 B.C.),

Marksville (A.D. 0-400), Baytown-Troyville (A.D. 400-700), Coles Creek (A.D. 700-

1000), the Mississippian (or Plaquemine) (A.D. 1200-1700), and into Colonial and

modern historic times. A sugar economy dominated the agrarian market from the late

1840s through the Civil War, with some thirty to forty plantations eventually constructed

along Bayous Boeuf, Shaffer, Black, Du Large, and parts of the Lower Atchafalaya

River. Confederate fortifications were established at the confluence of Bayous Shaffer

and Chene, and on the west bank of the Atchafalaya River at its junction with Little Wax

Bayou. Subsequent Union army occupation of the entire study area, as far west as

Berwick Bay, produced additional fortifications along the northernmost edge of the

Terrebonne marshes. Restoration period economic activity continued to focus on sugar

under a share-crop system supplemented by shell fish production and to a lesser extent

lumber extraction. After the early 20th century discovery of oil and gas these industries

have dominated the regional economy.

The marshes are an extremely dynamic environment where sites are subject to erosion,

alluviation, and subsidence. Therefore, the physical integrity or visibility of sites that

may have been present when previous studies were undertaken might now be in question.

The following recommended strategy for sites assessment and discovery as the project

goes forward has been coordinated with both the State of Louisiana SHPO and

archaeologists at the U.S. Army Engineer District New Orleans.

Determine which sites may be impacted by the current plan that have been listed

eligible or recommended as potentially eligible for inclusion in the Nation Register

of Historic Places (NRHP) by previous surveys.

Reassess the current condition of those previously recommended sites.

Perform Phase I field inspections and limited subsurface testing in areas where

structures associated with the implementation of the plan will be installed to

identify sites not previously discovered or recorded. Geotechnical data gathered in

the areas of planned construction are extremely useful for this and should be

accessed/shared with the archaeologist/cultural specialist.

Monitor construction to record unanticipated site disturbance for sites not

previously identified (i.e., sites below the surface not discovered via the methods

outlined above. The likelihood of encountering buried cultural material in the

course of mechanical excavation increases because of alluviation and subsidence.

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Following sections describe the physiographic setting, geomorphic history and the

previous research conducted within the study area. Statistical modeling is used to

examine correlations between settlement and prominent landforms.

2.1 Consultations

Both the SHPO and Tribes were contacted by the St. Louis District Engineering and

Construction Division Curation and Archives Analysis Branch between mid-May and

early-June of 2009. SHPO notification is dated May 19, 2009 and was sent to the

attention of Mr. Scott Hutcheson, Office of Historic Preservation, Capitol Annex

Building, P.O. Box 44247, Baton Rouge, Louisiana 70804. Tribal notification was sent

by the districts Native American Coordinator, Roberta L. Hayworth, to elected Tribal

Leaders and appointed Tribal Representatives for the following Nations.

Alabama Coushatta Tribe of Texas

Caddo Nation of Oklahoma

Chitimacha Tribe of Louisiana

Choctaw Nation of Oklahoma

Coushatta Tribe of Louisiana

Jena Band of Choctaw

Mississippi Band of Choctaw

Quapaw Tribe of Oklahoma

Seminole Nation of Oklahoma

Seminole Tribe of Florida

Tunic-Biloxi Tribe of Louisiana

No written responses to these notifications were received by the St. Louis District Office.

Visits to the Baton Rouge Office of Historic Preservation were undertaken by St. Louis

District cultural resources POC, Susan Malin-Boyce, on February 19, 2009 and February

20, 2009 to meet with the Louisiana State Archaeologist and review survey reports for

the proposed project area. Subsequent meetings with the Louisiana State Archaeologist

were attended on July 1, 2009, and November 4, 2009. A draft copy of this report

Appendix was submitted to the Louisiana State Archaeologist for review and comment.

In a response via email correspondence (December 28, 2009) Dr. McGimsey expressed

an interest in potential time and budget impacts in the event that archaeological materials

are recovered during monitoring, and concern for the development of a strategy for

assessing long-term effects of project implementation. Specifically, he wanted to know

when during the planning process such a strategy might be forthcoming.

A notice in intent to prepare a draft EIS for this project was published in the Federal

Register (Vol. 73 No. 246) on December 22, 2008. Two public scoping meetings have

been held, first on February 3, 2009, and on the following day, February 4, 2009 in

Houma and Morgan City respectively. More than 350 media outlets were provided with

the advisory announcing these meetings.

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3.1 Physiographic Setting

The project area is located within the Mississippi Alluvial Plain physiographic section

(Fenneman and Johnson 1946) (Figure 1). It lies to the southwest of the current course of

the Mississippi River at the distal end of the valley known as the deltaic plain.

Figure 1. Physiographic sections along the lower Mississippi

Within a deltaic plain, landforms and the physical environment in general are the

predominate factors influencing where people lived and interacted with their environment

during both the prehistoric and historic periods. Micro-scale changes in elevation could

determine which areas were habitable and which were inundated, while significant

shoreline changes could occur in a relatively short period of time. An understanding of

the regions geomorphic setting and processes is thus critical in predicting where human

habitation may have occurred over time and where the archaeological record might best

be preserved.

4.1 Geomorphic History

The geomorphic history of the delta has been the subject of many studies in the past half

century (e.g., Fisk 1944, Kob and Van Lopik 1958, Frazier 1967, Smith et al. 1986).

While certain aspects of the developmental history remain contentious, a broad

geomorphic sequence has achieved general acceptance (Weinstein and Kelly 1992:3).

The surface landforms dominating the project area have been formed within the last 9000

years (Frazier 1967). The first period of delta building dating from 9000 to 6500 B.P. is

known as the Maringouin (Figure 2). The sea level rise and erosion have since caused a

shoreline regression of over 40 miles.

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Figure 2. Historic delta sequence (after Weinstein and Gagliano 1985: Fig. 1)

Around 5800 years B.P. sea level had risen to approximately the present elevation and the

Mississippi began prograding a new delta known as the Teche. There is some debate

over the exact age of the delta, with Smith et al. (1986:61-62) suggesting the major

deposition happened ca. 4500 to 3500 B.P., while Weinstein and Gagliano (1985:123)

propose an earlier date of 5800 to 3900 B.P.

The main channel of this system has since been reoccupied by bayous Teche, Beuf,

LOurse and Black (Weinstein and Kelley 1992:3). Its natural levees still exist as raised

surface exposures up to a mile wide. The major distributaries of this main channel all

trend to the southeast and include Bayou Cocodrie, Bayou Piquant, Bayou Penchant,

Carencro Bayou and Little Horn Bayou. Their natural levees are considerably smaller

than the main channel and indeed some have completely subsided beneath the delta

marshes. Weinstien and Galiano (1985:123) also attribute several southwesterly trending

distributaries, including Bayou du Large, Bayou Mauvais Bois and Small Bayou La

Point, to the Teche Delta while Smith et al. (1986:64-67) argue that the latter date to

subsequent episodes of delta progradation.

Approximately 4800 B.P. the Mississippi River started shifting from the Teche course

and creating a new delta to the east known variously as the Cocodri, Metairie, or earlystage St. Bernard Delta (Weinstein and Kelly 1992:4-5). While the Mississippi shifted to

the east, the old course of the Teche was eventually occupied by the Red River. The

duration of this occupation has been debated, with Russ (1975:163-166) arguing that it

was only a relatively short term event. Based on archaeological evidence other scholars,

however, have suggested that the Red River only abandoned the Teche around 1800-1900

B.P. (see Weinstein and Kelly 1992:5).

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Gradually, the Mississippi shifted away from the St. Bernard Delta to the Bayou

Lafource, which reached its peak flow about 2000 B.P creating new delta lobes and

reoccupying old Teche distributaries such as Bayou Black and Bayou LOurse. As noted

previously, Smith et al. (1986:64) argue that the southwestern trending distributaries in

the region were formed at this time. Around 1000 B. P. the Mississippi again shifted its

course to the east and began building the Plaquemines Delta and subsidence and marsh

transgression became the dominant processes with the Terrebonne marsh (Weinstein and

Kelly 1992:5).

5.1 National Register of Historic Places

There are eight (8) locations listed on the National Register than are within the project

boundary (Table 1 and Figure 3). There are an additional six (6) within a one kilometer

radius of the area (Table 2).

Table 1. NR listed properties within project boundary

Name

Date

Published Address Location Description

Atkinson Memorial

Presbyterian Church 3/19/91 214 Fourth Street Morgan City Gothic Revival Bld

Brubaker House 2/29/95 1102 Second Street Morgan City Stick/Eastlake Bld

Gibson Methodist Episcopal

Church 5/8/86 S. Bayou Black Drive Gibson Greek Revival Bld

Montegut School 10/7/93 1137 LA 55 Montegut Building

Morgan City Historic District 1/9/86 N/A Morgan City District

Residence Plantation House 9/8/01 8951 Park Avenue Houma Stick/Eastlake Bld

U. S. Post Office 12/17/82 1st and Everett Streets Morgan City Beaux Arts Bld

Wesley House 8/11/82 1210 E. Main Street Houma Greek Revival Bld

Table 2. NR listed properties within one kilometers of project area

Name

Date

Published Address Location Description

Argyle 7/1/94 3313 Bayou Black Dr Houma Colonial Revival Bld

Golden Meadow High School 11/23/98 630 S. Bayou Drive

Golden

Meadow Classical Revival Bld

Orange Grove Plantation House 3/26/80 W of Houma on U.S. 90

Houma

vicinity Greek Revival Bld

Smith, Clifford Percival, House 4/20/89 501 E. Park Avenue Houma Queen Anne Bld

Southwest Reef Lighthouse 9/12/91

Jct. of Bellevue Front and

Canton Streets Bewick Structure

St. Matthew's Episcopal Church 5/1/89 243 Barrow Street Houma Gothic Revival Bld

Of the National Register locations, only the Wesley House is located in close proximity

to a potential project feature being within 100 meters from features CC2 and CD4. A

private cemetery associated with the Wesley House is within the AOE of CD4 (see

discussion of the Gagne Cemetery at end of report).

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Figure 3. Map of proposed project area displaying listed National Register locations

Figure 3. Map of proposed project area displaying listed National Register locations

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6.1 Known Archaeological Surveys

Assuming a typical survey corridor of 100 meters, a total of 19,910 acres within the

proposed project area have been recorded as having undergone an archaeological survey.

This amounts to just under three percent of the total area (Table 3). This number may be

an underestimate as many recorded sites fall outside the recorded survey tracks (Figure

4). Older surveys may not be recorded on the maps of the Louisiana State Historical

Preservation Office from which this dataset was derived.

Table 3. Metrics of archaeological surveys within project boundary

Project Area Sq Meters Ha Acres Percent Note

Lake Boudreaux 595,851,917.6 59,585.2 147,238.2

Grand Bayou 1,773,445,986.0 177,344.6 438,228.0

Bayou Penchant 478,948,908.7 47,894.9 118,350.9

Total 2,848,246,812.3 284,824.7 703,817.1

Survey Tracks (> 25 acres)

22-2115 31,409,226.8 3,140.9 7,761.4

22-174 1,634,888.0 163.5 404.0

22-3149 1,561,435.1 156.1 385.8

22-1194 268,490.5 26.8 66.3

22-1050 208,533.0 20.9 51.5

22-147 171,531.3 17.2 42.4

22-3189 145,273.5 14.5 35.9

22-1194 129,014.6 12.9 31.9

22-284 125,935.5 12.6 31.1

Total 35,654,328.3 3,565.4 8,810.4 1.25%

Linear Survey (>2 miles) Meters Km Miles

22-80 114,426.3 114.4 71.1

22-106 96,220.6 96.2 59.8

22-398 65,340.9 65.3 40.6

22-317 61,763.8 61.8 38.4

22-675 34,737.6 34.7 21.6

22-2019 31,570.6 31.6 19.6

22-977 22,699.7 22.7 14.1

22-1205 17,539.3 17.5 10.9

22-1050 15,823.2 15.8 9.8

22-1482 11,779.3 11.8 7.3

22-901 11,530.8 11.5 7.2

22-1987 10,699.4 10.7 6.6

22-1160 10,058.0 10.1 6.2

22-1597 8,726.2 8.7 5.4

22-386 8,399.3 8.4 5.2

22-2968 7,065.5 7.1 4.4

22-1206 6,541.6 6.5 4.1

22-818 5,689.3 5.7 3.5

22-359 5,451.0 5.5 3.4

22-1267 4,717.0 4.7 2.9

22-272 4,579.9 4.6 2.8

22-2304 4,318.6 4.3 2.7

22-3362 3,937.5 3.9 2.4

Total 449,188.9 449.2 279.1 1.58% ( w/100m corridor)

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Project Area Sq Meters Ha Acres Percent Note

Total Area Surveyed as percent of Project Area 2.83%

Figure 4. Map of proposed project area with known archaeological surveys and sites

7.1 Project Area Reconnaissance

On May 6, 2009 and May 7, 2009 a reconnaissance was conducted by members of the

Project Delivery Team, representatives from the U. S. Fish and Wildlife Service and

other state agencies to familiarize team members with the physical geography,

biodiversity and cultural resources of the project area. Approximately 264 linear

Figure 4. Map of proposed project area with known archaeological surveys and sites

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kilometers within the project boundary were examined during the trip (Figure 5). The

routes selected were targeted toward potential feature areas that will be impacted if the

project goes to construction.

Figure 5. Map of routes taken by investigators during project reconnaissance

8.1 Site Population

There are 290 known archaeological sites within the proposed project area. Of these, 283

are represented within the project GIS database by polygon features and seven by points. Figure 5. Map of routes taken by investigators during project reconnaissance

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This dataset was derived from both the on-line dataset of the Louisiana Division of

Archaeology and sites digitized manually after a visual examination of the legacy 7.5

minute quad maps at the Louisiana State Historic Preservation Office. One

archaeological site thought to be in the area (16TR80) is not in the on-line dataset and

was not located on the quad maps. The site files for the majority of these sites do not list

their National Register status (Table 4).

Table 4. NRHP status for sites within project boundary

Status No.

No Status Listed 29

Declared Eligible 8

Not Eligible 84

Recommended Eligible 28

Unknown 141

9.1 Site Cultural/Temporal Affiliation

The primary cultural/temporal associations for the archaeological sites within the

proposed project area as listed in their site record forms are presented in Table 5.

Table 5. Cultural/temporal affiliation of sites within project boundary

Affiliation No.

No affiliation listed 29

Antebellum 4

Baytown 2

Civil War 13

Coles Creek 31

Historic (unk) 16

Industrial Modern 50

Marksville 12

Mississippian 5

Neo-Indian (unk) 43

Prehistoric and Historic (unk) 2

Poverty Point 1

Plaquemine 17

Prehistoric (unk) 52

Tchefuncte 1

Troyville 12

Discounting those sites with no listed affiliation or those given a generic prehistoric or

prehistoric and historic classification, the most common designation is Neo-Indian

followed by Mississippian and Industrial/Modern (Figure 6).

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Figure 6. Chart showing chronology of cultural periods and number of sites within project area so designated (in circle)

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Figure 6. Chart showing chronology of cultural periods and number of sites within project area so

designated (in circle)

10.1 Site Locations

A STAC (Spatial and Temporal Analysis of Crime) algorithm was used to perform a

cluster analysis of the known archaeological sites. STAC was among the first clustering

techniques developed for use in spatial analysis within GIS (Levine 2004:7.1). The

techniques scan-type algorithm overlays a circle of a given size on each node of a grid

defining the study area, counts the number of points contained within, and then combines

overlapping clusters until none remains. The user provides the minimum number of

points to be considered and the search radius (in this case 10 and 5 miles respectively).

Combining aspects of hierarchical (the aggregation of smaller clusters) and partitioning

(the use of search circles) methods, STAC is very flexible and complements hierarchical

clustering well (Leveine 2004:7.17).

Known archaeological sites cluster in three main regions (Figure 7). Eighty eight (88)

sites are located in the extreme northwest section of the proposed project area. These

sites are situated around Lake Palourde and Six Mile Lake (Avoca Lake) as well as in and

around the municipalities of Morgan City and Amelia (i.e., the Morgan City Micropolitan

Statistical Area). With a minimum convex polygon of less than 62,000 acres, this cluster

averages one site per 705 acres. The second cluster is more dispersed with 165 sites

populating a minimum convex polygon of approximately 260,000 acres for an average of

one site per 1575 acres. The second cluster covers the central third of the project area

centered on Bayou du Large. The smallest cluster exists on the central reach of Bayou

Pointe au Chien and Grand Bayou Canal were 21 sites are spread over a minimum

convex polygon of 25,000 acres.

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Figure 7. Major site clusters within project boundary

11.1 Site Landform Associations as listed on Site Record Forms

The vast majority of site record forms list natural levee as the landform associated with

the sites with no other single category representing any significant percentage (Table 6).

Table 6. Landform listed on State Site Record Forms

Landform No.

No landform listed 29

Batture (elevated river bed) 2

Beach deposit 11

Chenier (beach ridge on swamp) 1

Marsh 15

Natural levee 198

Other 25

Ridge 3

Swamp 4

Underwater 2

12.1 Site Regional Landform Associations

Site correlation to regional-scale landforms was also undertaken within the project GIS.

Site features were spatially joined to a digitized version of a 1:500,000 scale Geologic

Map of Louisiana developed by the Louisiana Geological Survey (Figure 8). The

relatively small scale of the map lead to some sites falling into obviously incorrect areas

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(e.g., known terrestrial sites falling into the water category). Moreover, the map scale

only allows the broadest expression of landforms to be mapped. Natural levees, for

example, are limited to major ones located along the primary bayous.

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Figure 8. Geologic map of proposed project area with known archaeological sites

Figure 8. Geologic map of proposed project area with known archaeological sites

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The number of sites located on alluvium and natural levees is clearly higher than

what would have been expected given a random distribution of sites across the landscape.

A chi-squared goodness-of-fit test was conducted to assess the statistical association

between sites and the mapped landform. Based upon the total area of the various

geologic categories within the project area an expected number of sites to be located

within each category were generated. This expected number of sites was compared to the

known number and a chi-square test used to assess the statistical significance of the

difference (Table 7). The results indicate that it is statistically considered extremely

unlikely that the distribution would have occurred randomly.

Table 7. Non-random distribution of sites verses geography of project area

Geography Sites Percent Sq Meters Percent Expected

Alluvium 44 15.17% 361,872,321 12.71% 37

Delta Plain, Fresh Marsh 83 28.62% 1,404,281,006 49.30% 143

Delta Plain, Saline Marsh 61 21.03% 591,351,869 20.76% 60

Natural Levees 92 31.72% 246,681,233 8.66% 25

Water 10 3.45% 244,060,751 8.57% 25

290 100% 2,848,247,179 100% 290

Chi squared equals 215.076 with 4 degrees of freedom.

The two-tailed P value is less than 0.0001

By conventional criteria, this difference is considered to be extremely statistically significant.

As the boundaries between Fresh Marsh and Saline Marsh categories were thought to

be temporally sensitive, they were combined and the analysis performed again (Table 8).

Again, the difference in distributions was considered extremely significant.

Table 8. Non-random distribution of sites verses geography of project area (single marsh category)

Geography Sites Percent Sq Meters Percent Expected

Alluvium 44 15.17% 361,872,321 12.71% 37

Delta Plain 144 49.66% 1,995,632,875 70.07% 203

Natural Levees 92 31.72% 246,681,233 8.66% 25

Water 10 3.45% 244,060,751 8.57% 25

290 100% 2,848,247,179 100% 290

Chi squared equals 207.032 with 3 degrees of freedom.

The two-tailed P value is less than 0.0001

By conventional criteria, this difference is considered to be extremely statistically significant.

Given the statistics presented above, it might be proposed that levees and areas of

alluvium were preferentially selected for site location by people. Other mitigating

factors, however, need to be taken into account. For example, the perceived preference

of site location may be simply be a function of where archaeological surveys have

historically been undertaken. Indeed, when the known geologic provenience of survey

tracks are themselves queried against a random landform distribution, the difference is

consistently statistically significant (Table 9). The results are not dissimilar to

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site/geologic correlations with alluvium and natural levees being over represented.

In simple terms, at least some of the apparent site location preferences are doubtless

attributable to the bias for archaeological surveys to be conducted on those landforms.

Table 9. Non-random distribution of survey tracks vs. geography of project area

Geography Sq. Meters Percent Sq Meters Percent Expected

Alluvium 12,306,373 14.67% 361,872,321 12.71% 10,657,166

Delta Plain, Fresh Marsh 44,167,506 52.65% 1,404,281,006 49.30% 41,356,177

Delta Plain, Saline Marsh 10,516,218 12.54% 591,351,869 20.76% 17,415,355

Natural Levees 12,430,092 14.82% 246,681,233 8.66% 7,264,780

Water 4,460,896 5.32% 244,060,751 8.57% 7,187,607

83,881,086 100.00% 2,848,247,179 100% 83,881,086

Chi squared equals 7886424.459 with 4 degrees of freedom.

The two-tailed P value is less than 0.0001

By conventional criteria, this difference is considered to be extremely statistically significant.

To account for this survey locational bias, a further couple of chi-square tests were

performed using the survey geological associations rather than the total project area

associations. In this way, if site associations with geologic categories are statistically

different from the survey areas association with those categories, it can be asserted that

the site associations are not solely attributable to the latter (Table 10 and Table 11).

Again, the two-tailed P value is considered very significant.

Table 10. Non-random distribution of sites vs. geography of linear survey area (proxy for bias)

Geography Sites Percent Sq Meters Percent Expected

Alluvium 44 15.17% 12,306,373 14.67% 43

Delta Plain, Fresh Marsh 83 28.62% 44,167,506 52.65% 153

Delta Plain, Saline Marsh 61 21.03% 10,516,218 12.54% 36

Natural Levees 92 31.72% 12,430,092 14.82% 43

Water 10 3.45% 4,460,896 5.32% 15

290 100% 83,881,086 100.00% 290

Chi squared equals 106.914 with 4 degrees of freedom.

The two-tailed P value equals 0.0001

By conventional criteria, this difference is considered to be extremely statistically significant.

Table 11. Non-random distribution of sites vs. geography of linear survey area (proxy for survey

bias) with single marsh category

Geography Sites Percent Sq Meters Percent Expected

Alluvium 44 15.17% 12,306,373 14.67% 43

Delta Plain 144 49.66% 54,683,724 65.19% 189

Natural Levees 92 31.72% 12,430,092 14.82% 43

Water 10 3.45% 4,460,896 5.32% 15

290 100% 83,881,086 100.00% 290

Chi squared equals 68.241 with 3 degrees of freedom.

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The two-tailed P value is less than 0.0001

By conventional criteria, this difference is considered to be extremely statistically significant.

This association of sites to levee and alluvial geological areas is not unexpected and

indeed, if anything, may be under-represented. An 1895 map of the region was digitized

and georeferenced for comparison to the geologic map (Figure 9). The areas in the

historic map without hatching represent natural levees and other elevated areas. The

hatched areas represent marshlands (there named prairie). The elevated areas

correspond well with the areas designated natural levee on the geologic maps and to a

lesser extent with those designated alluvium. It is interesting, however, that the historic

map shows the levees extending much further south along the bayous than the geologic

map. Consequently, many sites that are associated with marshland on the geologic map

are associated with natural levee land on the historic map. A clear example is the string

of sites along the lower Bayou du Large. Again, the chi-square statistic indicates that the

non-random correlation is highly significant.

Table 12. Non-random distribution of sites verses geography of project area from 1895 map

Landform Sites Percent Sq. Meters Percent Expected

Elevated 148 51.03% 630,218,211 22.13% 64

Prairie 137 47.24% 2,036,736,481 71.51% 207

Water 5 1.72% 181,292,121 6.37% 19

290 100% 2,848,246,812 100% 290

Chi squared equals 144.237 with 2 degrees of freedom.

The two-tailed P value is less than 0.0001

By conventional criteria, this difference is considered to be extremely statistically significant.

It is clear from both the micro-scale landforms listed on the State Site Record Forms

(Table 6) and the macro-scale landform statistics presented above that the elevated

landforms (i.e., natural levees and alluvium regions) are significantly more likely to

contain archaeological resources. As such, they are considered in this study as higher

probability areas while the delta marshes are considered lower probability areas.

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Figure 9. 1895 map of proposed project area showing known archaeological sites

Figure 9. 1895 map of proposed project area showing known archaeological sites

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13.1 Potential Disturbance from Project Features

Disturbances to archaeological resources can result from both construction of project

features and the long-term operational effects of the features in an integrated system.

While construction disturbances are relatively straightforward to quantify, operational

disturbances are harder to measure at this juncture.

Construction Disturbances

The following table (Table 13) details the expected temporary right of way (ROE) for the

61 project features proposed in the current range of alternatives. These areas are

expected to be disturbed by construction activity. A subtotal of the various landform

acreage affected is presented in Table 14. These numbers represent a sum for all the

features from all project alternatives.

Table 13. Temporary ROW of project features

Temporary Right of Way

ID Feature Name Geologic Landform Width

(ft)

Length

(ft)

Area

(acres)

EC2 East Culvert #2 Qdf (Quaternary delta, fresh) 100 100 0.2

EC3 East Culvert #3 Qdf 100 100 0.2

EC5 East Culvert #5 Qal (Quaternary alluvium) 600 700 9.6

EC6 East Culvert #6 Qnl (Quaternary natural levee) 100 100 0.2

EC7 East Culvert #7 Qnl 100 100 0.2

ED2 East Dredge Channel #2 Qal (65%), Qnl (11%), Qdf

(21%), Qds (3%)

280 56450 362.9

ED3 East Dredge Channel #3 Qdf (70%), Qal (18%), Qnl

(12%)

730 16483 276.2

ED5 East Dredge Channel #5 Qal 740 1100 18.7

ED6 East Dredge Channel #6 Qdf 550 17000 214.6

ED7 East Dredge Channel #7 Qdf 400 13200 121.2

EM1 East Marsh Creation #1 Qds (90%), Qdf (10%) 200 13,310 61.1

EM3 East Marsh Creation #3 Qds (Quaternary delta, saline) 200 36620 168.1

EG1 East Spoil Gap #1 Qdf 60.0

EG2 East Spoil Gap #2 Qdf 26.0

EP7 East Plug #7 Qds 360 175 1.4

EP8 East Plug #8 Qal (60%), Qnl (40%) 140 110 0.4

ES2 East Diversion Structure #2 Qal (90%), Qnl (10%) 600 700 9.6

EX1 East Removal #1 Qdf 150 115 0.4

EX2 East Removal #2 Qdf 170 115 0.4

CC1 Central Culvert #1 Qnl 150 200 0.7

CC2 Central Culvert #2 Qnl 150 200 0.7

CC3 Central Culvert #3 Qnl 120 100 0.3

CC4 Central Culvert #4 Qnl 100 100 0.2

CC5 Central Culvert #5 Qdf 100 100 0.2

CC6 Central Culvert #6 Qdf 100 100 0.2

CC7 Central Culvert #7 Qdf 100 100 0.2

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Temporary Right of Way

ID Feature Name Geologic Landform Width

(ft)

Length

(ft)

Area

(acres)

CC8 Central Culvert #8 Qdf (75%), Qal (25%) 100 100 0.2

CC9 Central Culvert #9 Qal 100 100 0.2

CC10 Central Culvert #10 Qal 100 100 0.2

CC11 Central Culvert #11 Qal 100 100 0.2

CC12 Central Culvert #12 Qal 100 100 0.2

CC13 Central Culvert #13 Qnl 200 800 3.6

CC14 Central Culvert #14 Qdf (60%), Qal (40%) 100 150 0.4

CC15 Central Culvert #15 Qdf 200 100 0.5

CD1 Central Dredge Channel #1 Qnl (53%), Qal (47%) 280 6000 38.6

CD2 Central Dredge Channel #2 Qdf 240 800 4.4

CD3 Central Dredge Channel #3 Qdf (55%), Qnl (45%) 220 4600 23.2

CD4 Central Dredge Channel #4 Qdf 270 1700 10.5

CD6 Central Dredge Channel #6 Qdf (54%), Qal (32%), Qnl

(14%)

290 7200 47.9

CD7 Central Dredge Channel #7 Qnl (62%), Qal (38%) 320 6700 49.2

CL1 Central Lock Complex #1 Qds

CLV1 Central Levee #1 Qal (86%), Qnl (14%) 160 5180 19.0

CLV2 Central Levee #2 Qnl (68%), Qal (32%) 160 1760 6.5

CM2 Central Marsh Berm #2 Qds 200 11255 51.7

CM3 Central Marsh Berm #3 Qds 200 8975 41.2

CM4 Central Marsh Berm #4 Qds 200 23358 107.2

CP1 Central Plug #1 Qnl 180 150 0.6

CP2 Central Plug #2 Qdf 70 100 0.2

CS1 Central Diversion Structure.

#1

Qdf (75%), Qnl (25%) 200 800 3.6

CT1 Central Terracing #1 Qds (82%), Qnl (18%) 395.0

CT2 Central Terracing #2 Qds 44.0

CT3 Central Terracing #3 Qds 120.0

CT6 Central Terracing #6 Qds 78.0

CT7 Central Terracing #7 Qds 91.0

CT8 Central Terracing #8 Qds 172.0

WD2 West Dredge Channel #2 Qdf 430 35500 350.4

WD3 West Dredge Channel #3 Qal 650 16500 246.2

WP1 West Plug #1 Qds 100 200 0.5

WO2 W. Shoreline Protection #2 Qdf 225 48200 249.0

WS4 West Diversion Structure #4 Qdf 200 1000 4.6

WW2 West Weir #2 Qds 100 1000 2.3

Total 3761.2

Table 14. Impacted geologic regions of combined project features

Code Description Area (acres) Percent

Qal Alluvium 605.44 16.17%

Qdf Delta Plain - Fresh Water 1635.03 43.67%

Qds Delta Plain - Saline Water 1269.48 33.91%

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Qnl Natural Levee 233.74 6.24%

3743.69 100.00%

Note: Discounting Water Classification

Operational Disturbances

While construction of individual project features has an immediate impact on their

surrounding environment, as an integrated system they are designed to affect the regional

environment at large. These operational disturbances are much more likely to affect

the cultural resources within the project area as they impact a much larger area than the

construction of individual features. Examples of such effects include increased erosion

of riverbanks and shorelines due to changing water flow patterns and increased

sedimentation or overburden. While the burying of archaeological resources is

generally considered a benign, or even beneficial, effect, erosion shorelines or river banks

is a major concern as it may result in the destruction of cultural resources. At this point

in the projects feasibility study, it is not possible to model the effects of the operational

disturbance to archaeological resources over the long term.

14.1 Known Sites Endangered by Project Features

Fourteen sites are located within 100 meters of a proposed project feature (Figure 10 and

Table 15), as the latter are represented within the project GIS. Two of the sites are within

10 meters and three are in actual contact with a project feature. Two of the sites are

described in their State Site Record files as being eligible for listing in the National

Register of Historic Places (NRHP), five as unknown and seven as not eligible.

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Figure 10. Sites within 100 meters of proposed project features

Figure 10. Sites within 100 meters of proposed project features

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Table 15. Archaeological sites within 100 meters of proposed project features

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Table 15. Archaeological sites within 100 meters of proposed project features

15.1 Testing Strategies

Testing strategies generally follow the procedures outlined in the Field and Report

Standards of the Louisiana Division of Archaeology. Relevant sections include

Reconnaissance Surveys, Phase I Surveys, Phase II Archaeological Testing and

Archaeological Monitoring. Deviations from these standards (in methodology, transect

widths etc.) are made to reflect specific project needs and goals. Areas to be tested at

this juncture are limited to those that are directly and immediately impacted by the

construction of project features. Areas potentially disturbed by the projects longer term

operational effects are not considered here.

Known resources impacted

A full archival investigation will be completed for each of the known archaeological sites

determined to be potentially impacted by the construction of project features. These

should include initial and updated site record forms as well as all archaeological reports

pertaining to the sites. In order to verify the location and current condition of these sites,

a reconnaissance will be undertaken and a fully documented site assessment produced.

Higher probability areas

Areas of raised land (e.g., natural levees) are considered higher probability areas. In

such cases traditional shovel test transects will be undertaken in accordance with the

Phase I Standards of the Louisiana Division of Archaeology. These include a mandated

30 meter distance between transects and a 30 meter spacing between STPs on those

transects and/or monitoring during feature construction. Other guidelines can be found

on the Divisions website (http://www.crt.state.la.us/archaeology/). In the case that

potential sites are discovered, they will be delineated following the given standards.

Lower probability areas

Lower probability areas are limited to inundated or marsh environments within the

project area. Traditionally, boat or airboats have been used to survey these areas are with

examinations being limited to exposed ground (such as remnant natural levees).

Limitations to such surveys, however, include excessive ingress and egress times for each

area of interest (AOI) and partial or limited visibility for areas not directly adjacent to

open water locations.

In order to maximize efficiency, lower probability areas will be surveyed by helicopter.

This technique allows the rapid investigation of a large amount of territory within a short

time period. Moreover, it enables examination of areas not easily accessible by water or

land. Sites characterized by Rangia shell and ceramic scatters have proven to be

generally visible. If potential sites are identified within the lower probability areas,

testing strategies outlined for higher probability areas will be followed.

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16.1 Summary

Two hundred and ninety (290) known archaeological sites are located in the

project area as currently delineated.

Many of these archaeological sites were recorded more than 20 years ago.

There is a relative paucity of previously identified archaeological sites that have

yielded datable materials.

Many sites that have reliable cultural associations were repeatedly occupied, so

for instance a site may have a Marksville (AD 1-400) occupation followed by

Baytown (AD 400-700) or Coles Creek (AD 700-1200), a Mississippian

occupation (AD 1200-1700), an early settlers farm and then a modern plantation

 because these were significant places in human memory, and also they were

strategically located on high ground and next to distributary channels.

Very few of the sites extend all the way back to the Poverty Point period (1000

BC to AD 1) and only a handful to the Marksville.

Any site likely to be adversely impacted in the course of this project should be

carefully considered for the contribution it may make to an understanding of the

prehistory of this area.

Sixty-five (61) project features have been considered for adverse effect and

budgetary purposes.

Fourteen (14) known archaeological sites are located within 100 meters of a

potential project feature.

Thirteen residential structures and one recreational structure will require

evaluation depending on the alternate chosen, as they will need to be relocated.

The National Register of Historic Places (NRHP) lists eight (8) locations within

the project boundary.

One (1) location listed on the NRHP (the Wesley House) is situated within 100

meters of a potential project feature.

A small family cemetery of probably under ten (10) interments associated with

the Wesley House (the Gagne cemetery) is within the APE of a project feature.

Operational effects (secondary impacts) of project features on the archaeological

landscape have not been modeled for this feasibility study as there is insufficient

information available to do so at this time.

A Programmatic Agreement (PA) to guide consideration of historic properties

relative to implementation of the LCA Program for ecosystem restoration

(including this undertaking) is being developed.

This PA will assist the Corps in meeting its responsibilities under Section 106 of

the National Historic Preservation Act for the LCA Program (including this

undertaking).

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17.1 References Cited

Fenneman, N. M., and Johnson, D. W.

1946 Physical Divisions of the United States. 1:7,000,000-scale map. USGS,

Washington, D.C.

Fisk, H. N.

1944 Geological Investigation of the Alluvial Valley of the Lower Mississippi River.

Mississippi River Commission, U. S. Army Corps of Engineers, Vicksburg.

Frazier, D. E.

1967 Recent Deltaic Deposits of the Mississippi river: Their Development and

Chronology. Transactions of the Gulf Coast Association of Geological

Societies 17: 287-315.

Kob, C. R. and J. R. Van Lopik

1958 Geology of the Mississippi River Deltaic Plain, Southeastern Louisiana.

Technical Report No. 3-483. Waterways Experiment Station, U. S. Army

Corps of Engineers, Vicksburg.

Levine, N.

2004 CrimeStat: A Spatial Statistics Program for the Analysis of Crime Incident

Locations (v. 3.0). Ned Levine & Associates: Houston, TX, and the National

Institute of Justice, Washington, D.C.

Russ, D. P.

1975 The Quaternary Geomorphology of the Lower Red River Valley, Louisiana.

Ph.D. dissertation, Pennsylvania State University. University Microfilms, Ann

Arbor.

Smith, L. M., J. B. Dunbar, and L. D. Britsch

1986 Geomorphological Investigation of the Atchafalaya Basin, Area West,

Atchafalaya Delta and Terrebonne Marsh. Technical Report NO. GL-86-3.

Waterways Experiment Station, U. S. Army Corps of Engineers, Vicksburg.

Weinstein, R. A. and S. M. Gagliano

1985 The Shifting Deltaic Coast of the Lafource County and its Prehistoric

Settlement. In The Lafourche Country: The People and the Land, edited by

Philip D. Uzer, pp. 122-149. Center for Louisiana Studies, University of

Southwestern Louisiana, Lafayette.

Weinstein, R. A. and D. B. Kelley

1992 Cultural Resources Investigations in the Terrebonne Marsh, South-Central

Louisiana. A report prepared by Coastal Environments, Inc. for the U.S. Army

Corps of Engineers, New Orleans

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18.1 Addendum: Gagne Private Cemetery

19.1 Background

The Real Estate division, in the course of their normal investigations, identified a

historic cemetery within the AOE of potential feature CD-4. CD-4 is a dredge feature

running alongside the Gulf Intracoastal Waterway (GIWW) and is situated wholly within

the boundary of Houma in Terrebonne Parish. The lot in which the cemetery is

reportedly located (parcel ID: A03C-42226) is immediately southeast of the intersection

of the Terrebonne Bayou and Intracoastal Waterway in Ward 03C (Figure 1). The lot

immediately to the north has the address of 8308 Main Street.

Figure 1. Current parcel lots in Houma, LA

Research failed to find any notation of the cemetery on historic Sanborn Maps (1924,

1939 and 1940), or historic USGS quad maps (1944, 1963, and 1974). Internet research

found a reference to a Zeringue Gagne private cemetery located southeast of the

intersection of the Terrebonne Bayou and Intracoastal Waterway (e.g., http://www.lacemeteries.com/Maps/Terrebonne/TB11MapVE.htm). One source (cited above) lists the

cemetery with a CSA attribution indicating that at least one Confederate States Army

veteran is interred at the location. As the cemetery is not in the SHPO or NR databases, it

appears it has never been evaluated for NRHP status.

The Louisiana Cemetery Board (LCB) maintains a database of cemeteries that are

licensed and/or registered, but does not include abandoned ones. A Gagne cemetery is

not listed in this database and none of the other entries appears to match the location. It

is assumed that it is an abandoned family graveyard.

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On Nov. 9th 2009, Project Manager John Peukert conducted a site visit to the location of

the cemetery. He reported that no grave markers were visible at that time. Subsequent

research, however, has determined the nature of the cemetery and the identities of the

individuals interred.

20.1 History of Cemetery Location

The history of the property prior to the purchase of Louisiana by the United States is

largely unknown. As Spanish records were unavailable and/or incomplete, however, in

the early 1800s the American State Papers were assembled. Settlers had to prove that

they had occupied and cultivated land to which they claimed. Those whose claims were

accepted gained patents to the land. Pierre Minoux was able to prove that he had

permission by a Spanish officer prior to December 20th, 1803 to settle 640 acres on both

sides of Bayou Derbonne (later Bayou Terrebonne) and that he had cultivated that land

(United States Congress 1834: 247). The land included the area now occupied by the

Gagne cemetery (Figure 2). In the 1830s Pierres widow, Marie Rose, divided the land

and sold it off in pieces.

Figure 2. Original land patents in Terrebonne Parish from 1830 survey

At some point, a four room, cypress, raised Greek Revival cottage was built in the

immediate area of the cemetery. Based upon its architectural style it has been dated to

the 1830s and therefore is probably related to the breakup of Minoux patent. The

building was expanded in the 1880s and again in the 1930s. It is one of the few

remaining examples of a Greek Revival plantation house in the parish and is

distinguished by its French hall-less plan. In 1982, it was placed on the National Register

of Historic Places. It is uncertain when the Gagne family acquired the house and

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associated property, but the first record of their presence in Terrebonne Parish is 1848

and the first known burial in the cemetery dates to 1859. In his obituary, Joseph Gagne is

described as dying at his residence near Houma suggesting that it was his purchase

(Louisiana Sugar Planters' Association 1890: 137-138).

The majority of the property stayed in the Gagne family until it was sold to Adam Boquet

after the death of Sarah Dunn Gagne circa 1917. Boquet quickly resold the property,

however, claiming that the building was haunted by the ghost of the latter (Hebert 1994).

The Gagne house along with 18 acres was acquired in 1919 by Ella K. Hooper and Laura

White, deaconesses of the Methodist Episcopal Church South, for use as a school for girls

to address the need for their education in the Houma area. The building became known

as the Wesley House, a common name for homes sponsored by the Methodist Church

that took in young girls to raise them in a Christian manner. Soon more structures were

built and the campus was named the MacDonell French Mission School. Around 1952,

MacDonell became a home serving children, who for various reasons, needed to live

away from their homes. It has since evolved into a therapeutic residential facility for

school-aged children owned by the MacDonell United Methodist Children's Services,

Inc.

Before the property was sold to the Methodist Church in 1919, a lot (approx. 315 x 80

feet) containing the Gagne family cemetery and frontage on Main Street was extracted

and remained in possession of the Gagne family. In a plat attached to the Westly House

NRHP recommendation (1982) it is labeled Harris Gagne or assigns (Figure 3). Harris

Gagne died in 1939 and it is unknown to whom the lot passed at that juncture.

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Figure 3. Sketch map from Wesley House NRHP nomination

This lot appears on the 1924 and 1940 Sanborn maps of the area (Figure 4 and Figure 5).

These show the Gulf Intracoastal Waterway excavated to the west of the property. In

1933, the region around the cemetery was annexed to Houma (Figure 6) and at some

point after 1940, the lot was divided in half to obtain the current configuration.

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Figure 4. 1924 Sanborn map of area near cemetery with modern shoreline indicated

Figure 5. 1940 Sanborn map of area near cemetery with modern shoreline indicated

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Figure 6. Land segments annexed to Houma

Published research lists eight headstone inscriptions in the graveyard (Terrebonne

Genealogical Society 1989: 203). These include four adults and four young children, two

of whom probably died during childbirth.

1) A Kind, Indulgent, Father

Joseph A. Gagne

Died

Feb. 16, 1890

Aged

65 Years 4 Months 13 Days

5) Daughter No Name

Died August 2, 1868

Aged 1 Hour

2) Our Dear Beloved Mother

Sarah A. Gagne

Died

July 18, 1803 [1903]

Aged

77 Years 6 Months 19 Days

6) James Bateman Gray

Died Nov 8, 1899

Aged 2 Months and 19 Days

3) Julia Danks Gagne

Died September 10, 1862

Age 2 Years and 1 Month

A Lovely Child

7) Mother

Sophy Gagne Gray

Born Jan. 16, 1870

Died Nov. 25, 1912

4) Son No Name

Died April 18, 1859

Aged 1 Hour

8) Father

David Fuqua Gray

Born Sept. 6 1859

Died May 27, 1943

Annexed

09/20/1933

Ordinance No.

2257-1

Annexed

03/20/1957

Ordinance No.

2254-1

Original Hache

Patent

1834

Annexed

02/27/1960

Ordinance No.

2388-1

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21.1 Brief history of the Gagne Brothers

The 1850 federal census for Terrebonne Parish lists a Frank Gagne as a 29 year old

merchant and a Joseph A. Gagne as a 24 year old clerk, both born in Canada. We

know from later documents that the two were brothers and it seems likely that Joseph

assisted Frank in his business as Franks real estate value was recorded to be $600, while

no value is assigned for Joseph (United States Census Bureau 1850: Sheet 315B). It is

probable that the brothers immigrated to Louisiana sometime in the mid 1840s as in his

1890 obituary, Joseph is described as being a pillar of the community for over forty

years(Louisiana Sugar Planters' Association 1890: 137-138). Joseph had four children

with the first being born in 1848 (Hebert 1974: 255). By 1850, it appears that the

brothers were solidly placed among the minor gentry in Houma.

As fitting for a member of the gentry, when the Civil War ensued Joseph Gagne was

commissioned into the Confederate Army as an officer. His record is summarized in

Booths work as:

Gagne, J. A., 2nd Lt. Capt. 1st Special Battn. (Rightor's) La. Inf. En. April 16, 1861,

Houma, La. Roll to May 31, 1861, Absent with leave. Roll for June 16, 1861,

Present. Promoted 2nd Jr. Lt., June 11, 1861. Roll for July and Aug., 1861, Present.

Regtl. Returns for Dec., 1861, and Jan., 1862, Present or absent not stated. (Booth

1920: 950)

Another Gagne is also listed as serving in the same battalion only this time as an enlisted

man. It is likely that he was a son or nephew of Joseph.

Gagne, E. O., Pvt. Co. E, 1st Special Battn. (Rightor's) La. Inf. En. April 16, 1861,

Houma, La. Roll to May 31, 1861, Absent with leave, sick. Roll for June 16 to Aug.

15, 1861, Present. Roll for July and Aug., 1861. Discharged on account of ill health,

Yorktown, by Gen. Magruder's order, July 7, 1861.

Within the 1st Special Battalion, Joseph was associated with Company E: the Grivot

Guards (Bartlett 1874: 253). In December 1861 he was nominated to be a Captain in the

Quartermaster Department (United States Senate 1904: 626). It appears he also took on

local responsibilities. In lieu of U.S. currency, paper money was issued by the Houma

Consolidated Association briefly during the early part of the Civil War. These notes

bore the signatures of A. J. Delaporte and Joseph Gagne, listed as the president and

treasurer of the parish police jury respectively (Ellzey 2009).

In May of 1862, a Union column conducted a punitive mission in Houma in retaliation

for a partisan ambush on a small group of wounded Union soldiers passing through the

area. After the column entered the town its commander, Lt. Colonel John Keith, issued a

proclamation stating that unless the perpetrators were identified, Houma would be burned

to the ground. A list of names was quickly produced by local citizens. While everyone

on the list was absent, having fled, all of their houses and other property were destroyed.

After fining the town for the expeditions expenses and making townsfolk rebury the two

Federal soldiers killed in the initial ambush, the column left. With them, they took a

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number of notable locals including a Captain Gayne (United States War Department

1886: 450-456). In an associated document accompanying Keiths report, a F. Gayne

is also listed as a prominent local in the town. It is likely that this individual is Frank

Gagne. Captain Gayne was likely Joseph Gagne. It is unknown when he was released

by Federal authorities, as are the activities of either brother during the remainder of the

war.

Records suggest that by at least the 1870s the Gagnes had financially prospered in

Houma. An indication of this relative affluence is seen in an 1879 appeals case involving

Joseph that was brought to the Louisiana Supreme Court (Robert 1880). As former

administrator of the succession, and tutor of the minor children of Frank Gagne, Joseph

had sold property belonging to the succession. At the probate sale, his wife purchased

a block of brick stores in the town of Houma, at the appraised value, $3000. After

fulfilling his responsibilities as administrator, he also resigned as tutor. The minors

subsequent Tutrix brought a case against Joseph and his wife the results of which were

appealed to the State Supreme Court.

22.1 Summary and Conclusion

The Gagne cemetery is a private family graveyard associated with the Wesley House, a

Greek Revival style plantation house probably built in the 1830s and listed on the

National Register of Historic Places (08/11/1982). The first Gagne associated with the

property is Joseph A. Gagne, a veteran of the Confederate States Army. Joseph

immigrated to Terrebonne Parish in the 1840s and died in 1890. The property stayed in

the Gagne family until 1917 when the bulk of it was bought by the Methodist Church to

become the site of the MacDonell School for girls, which still exists as the MacDonell

United Methodist Children's Services. Apparently, at the time of the sale to the church, a

small lot including the location of the cemetery was deducted from the larger property.

This lot continued to be owned by a Gagne until it was sold out of the family at some

unknown time.

The first identified burial at the cemetery dates to 1859 and the last to 1944. There are

only eight known interments at the location, although it is possible there are additional

unmarked graves, or some for which the headstone has been buried or otherwise

obscured. At the most, only three generations of the Gagne family occupied the

plantation, so it is probable that even given the latter case, the number of burials is

relatively small, almost certainly less than twenty. Being a small family cemetery, it

seems likely to be contained wholly within the approx. 80 by 155 foot lot. Indeed, it is

possible the lots dimensions were designed to this effect. It is therefore unlikely that the

cemetery was affected by the construction of the Gulf Intracoastal Waterway. As no

grave markers were located during the November site visit, it is possible that they were

removed sometime after their 1989 documentation. Given that situation, however, it is

still unknown if the graves themselves would have been relocated. Alternately, the grave

markers many simply have been obscured or buried at the time of the visit.

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In accordance with the terms of the PA, a subsequent Phase I investigation will make a

recommendation on the NRHP eligibility of this property, either on its own or as part of

the Wesley House, which is a NR site.

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23.1 References Cited

Booth, A. B.

1920 Records of Louisiana Confederate Soldiers and Louisiana Confederate

Commands. Louisiana Military Records, New Orleans.

Hebert, D. J.

1974 Southwest Louisiana records: church and civil records of settlers. Volume 5.

Donald J. Hébert, Eunice, LA.

Hebert, T.

1994 Methodism along the Bayou. Electronic document, http://www.gbgmumc.org/history/hist1.htm, accessed December 15, 2009.

Louisiana Sugar Planters Association

1890 The Louisiana planter and sugar manufacturer. Volume 4, Number 9.

Louisiana Sugar Planters Association, New Orleans.

Napier, B.

1874 A Soldiers Story of the War: Including the Marches and Battles of the

Washington Artillery and of Other Louisiana Troops. Clark & Hofeline, New

Orleans.

Robert, P.

1880 Reports of cases argued and determined in the Louisiana Supreme Court,

Volume XXXI for the year 1879. No. 7359. F. F. Hansell, New Orleans.

Terrebonne Genealogical Society

1989 Cemeteries of Houma Louisiana. Terrebonne Genealogical Society, Houma,

LA.

United States Census Bureau

1850 State: Louisiana, Parish: Terrebonne, Sheet No: 315A . United States Census

Bureau, Washington, D.C.

United States Congress

1834 American State Papers, Public Lands. Volume 3. Duff Green, Washington,

D.C.

United States Senate

1904 Journal of the Congress of the Confederate States of America, 1861-1865.

Volume I. Government Printing Office, Washington, D.C.

United States War Department

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1886 The War of the Rebellion: A compilation of the Official Records of the Union

and Confederate Armies. Series I, Volume XV. Government Printing Office,

Washington, D.C.

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Programmatic Agreement

Followed by Notification of Interested Parties to

the Programmatic Agreement

807
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

WHEREAS, the United States Army Corps of Engineers (USACE), in cooperation with

the Coastal Protection and Restoration Authority of Louisiana (CPRA), has been working

to reverse the current trend of coastal degradation; and

WHEREAS, the Louisiana Coastal Area Plan (LCA Plan) is the recommended plan

resulting from the Louisiana Coastal Area Ecosystem Restoration Study, completed in

November 2004 and recommended to the Congress by a Chief of Engineers report dated

January 31, 2005; and

WHEREAS, Section 7006 of the Water Resources Development Act (WRDA) of 2007

(Public Law 110-114) includes conditional authorization for the LCA Plan; and

WHEREAS, the LCA Plan calls for a coordinated, feasible solution to the identified

critical water resource problems and opportunities in coastal Louisiana and includes

fifteen (15) near-term critical restoration features (Undertakings); and

WHEREAS, the USACE has determined that the restoration features are undertakings as

defined in the regulations of the Advisory Council on Historic Preservation (ACHP)

implementing Section 106 of the National Historic Preservation Act (36 CFR § 800) that

may affect properties included in or eligible for inclusion in the National Register of

Historic Places (NRHP); and

WHEREAS, the USACE has consulted with the ACHP and the Louisiana State Historic

Preservation Officer (SHPO) to develop this Programmatic Agreement (Agreement)

pursuant to 36 CFR § 800.14(b)(1) of the ACHPs regulations implementing Section 106;

and

WHEREAS, Section 7006(e)(3) of WRDA 2007 requires submittal of additional

feasibility reports on the following six (6) of the fifteen (15) near-term critical restoration

features identified in the 2004 LCA Study: (1) Multipurpose Operation of Houma

Navigation Canal Lock, (2) Terrebonne Basin Barrier Shoreline Restoration, (3) Small

Diversion at Convent/Blind River, (4) Amite River Diversion Canal Modification, (5)

Medium Diversion at Whites Ditch, and (6) Convey Atchafalaya River Water to

Northern Terrebonne Marshes; and authorizes construction of those six features

substantially in accordance with the recommendations presented in a final report of the

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Chief of Engineers if a favorable report of the Chief is completed by not later than

December 31, 2010; and

WHEREAS, Section 7006(e)(1) of WRDA 2007 requires submittal of feasibility reports

on the following four (4) of the fifteen (15) near-term critical restoration features

identified in the 2004 LCA Study: (1) Land Bridge between Caillou Lake and the Gulf of

Mexico, (2) Gulf Shoreline at Point au Fer Island, (3) Modification of Caernarvon

Diversion, and (4) Modification of Davis Pond Diversion; and authorizes construction of

those four features if the Secretary of the Army determines that the projects are feasible;

and

WHEREAS, Section 7006(c) of WRDA 2007 requires submittal of construction reports

on the following five (5) of the fifteen (15) near-term critical restoration features

identified in the 2004 LCA Study: (1) Mississippi River-Gulf Outlet Environmental

Restoration, (2) Small Diversion at Hope Canal, (3) Barataria Basin Barrier Shoreline

Restoration, (4) Small Bayou Lafourche Reintroduction, and (5) Medium Diversion at

Myrtle Grove; and authorizes construction of those five features substantially in

accordance with the report of the Chief of Engineers dated January 31, 2005; and

WHEREAS, the USACE has elected to fulfill its obligations under Section 106 of the

National Historic Preservation Act of 1966, as amended, through the execution and

implementation of this Agreement as provided in 36 CFR § 800; and

WHEREAS, the Undertakings, including stipulations of the Agreement, are subject to

provisions of the Antideficiency Act (31 U.S.C. § 1341), the unavailability of funds shall

not relieve the USACE from its obligation to perform those Section 106 responsibilities

set forth in the Agreement; and

WHEREAS, the USACE, ACHP, SHPO, and Indian tribes as defined in 36 CFR §

800.16(m), representatives of local governments, and other appropriate parties have

consulted to develop this Agreement to define efficient and cost effective processes and

protocols for taking into consideration the effects of the Undertakings upon historic

properties pursuant to 36 CFR § 800.14(b)(1); and

WHEREAS, the USACE acknowledges Indian tribes as sovereign nations which have a

unique government-to-government relationship with the federal government and its

agencies; the USACE further acknowledges its Trust Responsibility to those recognized

Indian tribes; and

WHEREAS, the USACE has notified affected Indian tribes and shall fulfill its tribal

consultation responsibilities through ongoing consultation with Indian tribes that attach

religious and cultural significance to historic properties that may be affected by the

Undertakings; and

WHEREAS, the USACE has decided that it will invite any interested Indian tribe to sign

this Agreement as a concurring party; and

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WHEREAS, the CPRA has been invited to be a signatory to this Agreement; and

WHEREAS, the USACE, in coordination with the SHPO, has taken appropriate measures

to identify other consulting parties and to invite such parties to participate in the

development and execution of this Agreement; and

WHEREAS, the USACE has requested the participation of local governments and the

public by mail during the development of this Agreement and will take appropriate steps

to involve and notify those parties, as appropriate, during the implementation of the terms

of this Agreement; and

NOW, THEREFORE, the USACE, ACHP, and SHPO agree that the implementation of

the following stipulations will evidence that the USACE has taken into account the

effects of the Undertakings upon historic properties.

STIPULATIONS

The USACE shall adhere to the process and protocols set forth in this Agreement and

shall ensure the following stipulations are carried out.

I. Tribal Consultation

A. The USACE shall conduct government-to-government consultation with

Indian tribes that attach religious and cultural significance to historic

properties that may be affected by the Undertakings.

B. The USACE will develop protocols with Indian tribes with cultural,

religious, and/or ancestral ties to the Gulf Coast region to facilitate tribal

consultation regarding the potential effect of the Undertakings on

properties with tribal cultural or religious significance. The USACE

shall provide Indian tribes with copies of all plans, determinations, and

findings provided to the SHPO to assist the Indian tribes in identifying

activities that may be of interest.

C. Pursuant to this Agreement, the USACE will develop consultation

protocols with each Indian tribe, as requested, within ninety (90) days of

the execution of this Agreement unless that timeframe is modified by

written agreement.

D. The USACE has invited the Alabama Coushatta Tribe of Texas, the

Caddo Nation of Oklahoma, the Chitimacha Tribe of Louisiana, the

Choctaw Nation of Oklahoma, the Coushatta Tribe of Louisiana, the

Jena Band of Choctaw Indians, the Mississippi Band of Choctaw

Indians, the Quapaw Tribe of Oklahoma, the Seminole Nation of

Oklahoma, the Seminole Tribe of Florida, and the Tunica-Biloxi Tribe

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of Louisiana to consult in the development of the Agreement. The

Alabama-Coushatta Tribe of Texas and the Mississippi Band of

Choctaw Indians have participated in the development of the Agreement

and will each sign the Agreement as a concurring party. The USACE

will provide all invited Indian tribes with a copy of the Programmatic

Agreement and will invite them to sign the Agreement as concurring

parties.

II. Public Involvement

A. The USACE, in coordination with the SHPO, shall identify and provide

members of the public likely to be interested in the effects of the

Undertakings upon historic properties with a description of the

restoration features and the provisions of the Agreement.

B. The USACE will involve the public through the National Environmental

Policy Act (NEPA) process, which affords all persons, organizations and

government agencies the right to review and comment on proposed

major federal actions that are evaluated by a NEPA document. This is

known as the scoping process. The scoping process is the initial step

in the preparation of a NEPA document and will help identify (1) the

range of actions (project, procedural changes), (2) alternatives (both

those to be rigorously explored and evaluated and those that may be

eliminated), and (3) the range of environmental resources considered in

the evaluation of environmental impacts.

C. The USACE will release a draft of the NEPA document for each of the

Undertakings to the public for a review period. A public meeting

soliciting comments on the proposed action presented in each draft

NEPA document will be held during the public comment period.

Comments from this review period will be incorporated into each final

NEPA document.

D. To the extent permitted under applicable federal laws and regulations, the

USACE will release to the public documents developed pursuant to this

Agreement, including protocols, effects determinations, and Interim

Progress Reports.

III. Other Consulting Parties

A. The USACE, in coordination with the SHPO, will continue efforts

during the duration of this Agreement to identify other parties with

demonstrated interests in preservation issues and invite them to

participate as consulting parties.

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B. The USACE will document the consulting parties in the consultation

process for each of the Undertakings and maintain it as part of the

administrative record.

C. If any dispute arises about the right to be recognized as a consulting

party, the USACE will contact the ACHP and provide all appropriate

documentation. The ACHP will participate in the resolution of the issue.

IV. Identification, Evaluation, and Assessment of Effects Determinations

A. In coordination with the SHPO and Indian tribes, the USACE will

develop protocols for the identification and evaluation of historic

properties covered under the terms of this Agreement. Such protocols

also will address applicable professional standards, documentation

requirements for SHPO submissions, review procedures, and the

involvement of consulting parties. Identification and evaluation

protocols will be developed within ninety (90) days of the execution of

this Agreement unless that timeframe is modified by written agreement.

B. The USACE, in consultation with the SHPO and Indian tribes, will

define and document the area of potential effects (APE) for each of the

Undertakings based on the nature of the proposed construction, existing

information on the presence or absence of historic properties, the types

of historic properties expected to be encountered, the physical

characteristics of the APE, and the religious and cultural significance of

the APE to Indian tribes. The APE associated with each restoration

feature will anticipate the potential for direct, indirect, and cumulative

effects upon historic properties. Identification and evaluation efforts

will be limited to the APE once that APE is approved by the SHPO and

Indian tribes who have signed this Agreement.

C. In the event of disagreement between the USACE, SHPO, and/or Indian

tribes on the eligibility of a property for listing in the National Register

of Historic Places under 36 CFR § 60, the USACE shall request a formal

determination of eligibility for that property from the Keeper of the

National Register of Historic Places (Keeper). The determination by the

Keeper will serve as the final decision regarding the National Register

eligibility of the property.

D. All standard response timeframes established under 36 CFR § 800 will

apply during the interim period between the execution of this Agreement

and the adoption of identification and evaluation protocols, unless

otherwise agreed by the SHPO and Indian tribes. The USACE may

request expedited review by the SHPO and Indian tribes on a case by

case basis during the interim period.

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V. Coordination of Effects Determinations

A. The USACE shall evaluate effects of each of the Undertakings on

historic properties in a holistic manner. In the event the USACE

determines that any aspect of an Undertaking will have an effect or

adverse effect on a historic property within the restoration features

APE, the entire restoration feature will be reviewed accordingly.

B. In the absence of alternative response timeframes identified in approved

protocols developed pursuant to this Agreement, consultation under this

Agreement will be concluded for USACE findings of no historic

properties affected when the SHPO and Indian tribes have reviewed the

written documentation and concur with the USACE finding or do not

object within thirty (30) days of receipt of an adequately documented

finding.

C. Following submission of written documentation to the SHPO and Indian

tribes, the USACE may propose a finding of no adverse effect with

conditions, as appropriate. Such conditions may include, but are not

limited to:

1. Avoidance and/or preservation in-place of historic properties;

2. Unavoidable visual effects to historic properties in cases where

reasonable and practicable efforts to screen views are

considered and implemented; and

3. Modifications or conditions to ensure consistency with the

Secretary of Interiors Standards for the Treatment of Historic

Properties and applicable guidelines.

D. In the absence of alternative response timeframes identified in approved

protocols developed pursuant to this Agreement, consultation under this

Agreement will be concluded for USACE findings of no adverse effect

or no adverse effect with conditions when the SHPO and Indian tribes

have reviewed the written documentation and concur with the USACE

finding or do not object within thirty (30) days of receipt of an

adequately documented finding. The public shall also be afforded an

opportunity to comment.

E. Should the SHPO and/or Indian tribes object to USACEs findings of no

historic properties affected, findings of no adverse effect with

conditions, findings of no adverse effect, or should the USACE

determine that it cannot accept conditions requested by the SHPO and/or

Indian tribes, the USACE shall seek to resolve such objection through

consultation in accordance with Stipulation IX of this Agreement.

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VI. Resolution of Adverse Effects

A. In the event that the USACE, in consultation with the SHPO and Indian

tribes, determines that the implementation of an Undertaking may result

in an adverse effect upon historic properties as defined in 36 CFR §

800.5(a)(1) and (2) of the ACHPs regulations, the USACE shall notify

the ACHP, SHPO, Indian tribes, other consulting parties, and the public.

If the project activity will affect a National Historic Landmark, the

USACE shall also notify the National Park Service (NPS). The adverse

effect notification shall include the documentation specified in 36 CFR §

800.11(e), subject to the confidentiality provisions of 36 CFR §

800.11(c).

B. In the absence of alternative response timeframes identified in approved

protocols developed pursuant to this Agreement, the ACHP, SHPO,

Indian tribes, consulting parties, including NPS, as appropriate, and the

public shall be afforded an opportunity to review and comment on the

adverse effect notification for a period of thirty (30) days after receipt of

the adverse effect notification.

C. The USACE, in consultation with the SHPO, Indian tribes, other

consulting parties, and the ACHP if they notify the parties of their

participation pursuant to 36 CFR 800.6(a)(1)(iii), will develop treatment

plans for the resolution of adverse effects to historic properties within

sixty (60) days of the receipt of the adverse effect notification. Such

treatment plans will address measures to avoid, minimize, or mitigate

adverse effects on historic properties. Standard mitigation measures will

be tailored to the significance of the historic property, and may address

the following:

1. Public Interpretation;

2. Documentation consistent with the Level II Standards of the

Historic American Building Survey/ Historic American

Engineering Record (HABS/HAER);

3. Historical, Architectural or Archaeological Monographs;

4. Rehabilitation of historic buildings in accordance with the

Secretary of the Interiors Standards for the Treatment of

Historic Properties (36 CFR § 68);

5. Off-site mitigation, including acquisition of property or

preservation easements on property, as appropriate, containing

threatened resources of comparable significance in

814
Page 8

circumstances where there is an imminent need to proceed with

construction activity and it is in the public interest;

6. Ethnographic studies;

7. Studies of traditional cultural properties;

8. Relocation of historic properties to sites approved by the SHPO

as possessing similar overall character; and

9. Data recovery for archeological properties.

D. Once the consulting parties agree to a treatment plan for the resolution

of adverse effects on historic properties, the parties will execute a

memorandum of agreement.

E. Should the USACE, SHPO, and/or Indian tribes disagree on the

proposed mitigation measures, the USACE shall seek to resolve such

objection through consultation in accordance with Stipulation IX of this

Agreement.

F. As specified in Section 7(a) of Public Law 86-523, as amended by

Public Law 93-291 (16 U.S.C. 469c(a)), the USACE may not incur costs

for data recovery activities that exceed one percent of the total amount

authorized to be appropriated for the critical restoration feature, unless

and until the Assistant Secretary of the Army (Civil Works) has waived

that limit and the Secretary of the Interior has concurred in the waiver in

accordance with Section 208(3) of Public Law 96-515, as amended (16

U.S.C. 469c-2(3)).

VII. Unanticipated Discoveries and Effects

A. In the event that the USACE discovers a previously unidentified historic

property, including archeological sites, human remains, and properties of

traditional religious and cultural significance to Indian tribes, during the

execution of any of the Undertakings, the USACE immediately shall

secure the jobsite and suspend work in the vicinity of the affected

resource. The USACE shall immediately notify the SHPO, Indian tribes

consistent with tribal protocols, and other consulting parties, as

appropriate, should the proposed work adversely affect a previously

unidentified historic property or will adversely affect a known historic

property in an unanticipated manner. In accordance with Stipulation VI

of this Agreement, the USACE, in coordination with the ACHP, SHPO,

Indian tribes, and other consulting parties, as appropriate, will develop

standard mitigation measures. The USACE will implement the standard

815
Page 9

mitigation measures once approved by the ACHP, SHPO, Indian tribes,

and consulting parties, as appropriate.

B. In the event that the USACE discovers a previously unidentified burial,

including burial sites, human skeletal remains, or burial artifacts, on

private or state land during the execution of any of the Undertakings, the

USACE will follow procedures established in the Louisiana Unmarked

Human Burial Sites Preservation Act (R.S. 8:671-681).

C. In the event that the USACE discovers a previously unidentified burial,

including burial sites, human remains or funerary objects, on federal or

tribal land during the execution of any of the Undertakings, the USACE

will follow procedures established by the Native American Graves

Protection and Repatriation Act (NAGPRA) of 1990 and the regulations

that allow for its implementation (43 CFR § 10) and the Archaeological

Resources Protection Act of 1979 (Public Law 96-95; 16 U.S.C. 470aamm), as amended, and implementing regulations (32 CFR § 229).

D. The USACE shall insure that all contractors are made aware of the

requirements of this Agreement by way of its inclusion with solicitation

and award documentation. In the event that a contractor discovers a

previously unidentified historic property, the contractor shall

immediately notify the USACE, refrain from further project activities

within the immediate vicinity of the discovery, and take reasonable

efforts to avoid and minimize harm to the historic property. The USACE

shall implement additional measures to secure the historic property for

safety and security concerns, as appropriate.

E. In the event that previously unidentified direct adverse effects to historic

properties are identified following the completion of work within an

activity area, any party may provide the USACE with evidence of such

effects for a period of twelve (12) months from the completion of the

affecting work. The USACE, in consultation with the SHPO, Indian

tribes, and ACHP, as appropriate, will review the effect in accordance

with the provisions of this Agreement.

F. In the event that previously unidentified direct adverse effects to

structural historic properties are identified following the completion of

work within an activity area, owners of such affected properties may

provide the USACE with evidence of such effects for a period of twelve

(12) months from the completion of the affecting work. The USACE, in

consultation with the SHPO, Indian tribes, as appropriate, and the

ACHP, as appropriate, will review the effect in accordance with the

provisions of this Agreement.

816
Page 10

G. If the USACE, SHPO, Indian tribes, consulting parties, or member of the

public, as appropriate, cannot agree on an appropriate course of action to

address the discovery situation, the USACE shall initiate the dispute

resolution process set forth in Stipulation IX of this Agreement.

H. If, during performance of any relocations, construction of any

improvements required on lands, easements, and rights-of-way to enable

the disposal of dredged or excavated material, or performance of any

operation, maintenance, repair, rehabilitation and replacement

(OMRR&R) activities required for a critical restoration feature, the

CPRA discovers a previously unidentified historic property, including

archeological sites, human remains, and properties of traditional

religious and cultural significance to Indian tribes, the CPRA shall

immediately notify the USACE, refrain from further project activities

within the immediate vicinity of the discovery, and take reasonable

efforts to avoid and minimize harm to the historic property. The CPRA,

in coordination with the USACE, shall follow the procedures discussed

in paragraphs A. through C. of this Stipulation, as applicable. The

CPRA shall not proceed with performance of any relocation or

construction of any improvement that is related to such a discovery until

the USACE provides written notice to the CPRA that it should proceed

with such work.

I. The CPRA shall insure that its contractors are made aware of the

requirements of this Agreement by way of its inclusion with solicitation

and award documentation for activities related to performance of

relocations, construction of improvements, or OMRR&R activities

required for a critical restoration feature. In the event that a contractor

discovers a previously unidentified historic property, the contractor shall

immediately notify the CPRA, refrain from further project activities

within the immediate vicinity of the discovery, and take reasonable

efforts to avoid and minimize harm to the historic property. The CPRA

shall implement additional measures to secure the historic property for

safety and security concerns, as appropriate.

VIII. Treatment of Human Remains

A. Pursuant to this Agreement, the USACE, in consultation with the SHPO

and Indian tribes will develop protocols within ninety (90) days of the

execution of this Agreement that take into account all applicable laws

and regulations for the treatment of human remains that may be

encountered during any ground disturbing activities related to the

Undertakings.

817
Page 11

B. For human remains that are determined to be Native American, the

USACE will develop a subset of the treatment protocols in consultation

with the SHPO and Indian tribes.

C. The USACE or the CPRA, as applicable, will implement the approved

treatment protocols, in consultation with the SHPO and Indian tribes, in

the event human remains are encountered during any ground disturbing

activities related to the Undertakings.

IX. Dispute Resolution

A. Except for the resolution of eligibility issues, as set forth in Stipulation

IV.C. of this Agreement, should the SHPO, Indian tribes, or member of

the public disagree on the implementation of the provisions of this

Agreement, they will notify the USACE, who will seek to resolve such

objection through consultation.

B. If the dispute cannot be resolved through consultation, the USACE shall

forward all documentation relevant to the dispute to the ACHP,

including any proposed resolution identified during consultation. Within

seven days after receipt of all pertinent documentation, the ACHP may:

1. Provide the USACE with recommendations to take into

account in reaching final decision regarding the dispute; or

2. Notify the USACE that it will comment pursuant to 36 CFR §

800.7(c) and provide formal comments within twenty-one (21)

days.

C. Any recommendation or comment provided by the ACHP will be

understood to pertain only to the subject of the dispute, and the

USACEs responsibilities to fulfill all actions that are not subject of the

dispute will remain unchanged.

D. If the ACHP does not provide the USACE with recommendations or

notification of its intent to provide formal comments within seven (7)

days, the USACE may assume that the ACHP does not object to its

recommended approach and it will proceed accordingly.

X. Administration and Duration of this Agreement

A. This Agreement will become effective upon the date of execution by the

final signatory. The refusal of any party invited to concur in the

Agreement will not invalidate the Agreement.

818
Page 12

B. This Agreement will remain in effect for fifteen (15) years from the date

of execution, unless extended for a five-year period by written

agreement negotiated by all signatories by July 2025.

C. The USACE shall provide all signatories with annual Interim Progress

Reports, which will be submitted every twelve (12) months from the

execution date of this Agreement.

D. The consulting parties to this Agreement shall meet annually, or as

needed, to evaluate the effectiveness of this Agreement.

XI. Amendment and Termination

A. Notwithstanding any provision of this Agreement, the signatories may

request that it may be amended, whereupon the signatories will consult

to consider such amendment. The USACE will facilitate such

consultation, including Indian tribes, within thirty (30) days of the

request from one of the signatory parties. Any amendment will be in

writing and will be signed by the USACE, ACHP, SHPO, and CPRA,

and shall be effective on the date of the final signatory.

B. This Agreement may be terminated at the request of any of the signatory

parties within thirty (30) days following written notification to all

parties. In the event of termination, the USACE shall comply with 36

CFR § 800 on a case by case basis for all activities covered by the

Agreement.

819
820
821
822
Page 16

Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Execution of this Programmatic Agreement and implementation of its terms evidences

that the USACE has taken into account the effects of the LCA Plan upon historic

properties and has afforded the ACHP an opportunity to comment.

Signatory:

Advisory Council on Historic Preservation

By: Date:

John M. Fowler

Executive Director

Advisory Council on Historic Preservation

823
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Alabama Coushatta Tribe of Texas

By: Date:

Carlos Bullock, Tribal Council Chairman

824
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Mississippi Band of the Choctaw Indians

By: Date:

Beasley Denson, Chief

825
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Caddo Nation of Oklahoma

By: Date:

Brenda Shemayme Edwards, Chairperson

826
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Chitimacha Tribe of Louisiana

By: Date:

John Paul Darden, Chairman

827
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Choctaw Nation of Oklahoma

By: Date:

Gregory E. Pyle, Chief

828
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Coushatta Tribe of Louisiana

By: Date:

Kevin Sickey, Chief

829
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Jena Band of the Choctaw Indians

By: Date:

Christine Norris, Principal Chief

830
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Quapaw Tribe of Oklahoma

By: Date:

John Berrey, Chairman

831
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Seminole Nation of Oklahoma

By: Date:

Enoch Kelley Haney, Principal Chief

832
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Seminole Tribe of Florida

By: Date:

Mitchell Cypress, Chairman

833
Programmatic Agreement

among

the United States Army Corps of Engineers,

the Coastal Protection and Restoration Authority of Louisiana,

the Louisiana State Historic Preservation Officer,

and

the Advisory Council on Historic Preservation,

Regarding the

Louisiana Coastal Area Ecosystem Restoration Plan (LCA Plan)

Concurring Party:

Tunica-Biloxi Tribe of Louisiana

By: Date:

Earl J. Barbry Sr., Chairman

834
F-45

May 19, 2009

Engineering and Construction Division

Curation and Archives Analysis Branch

Mr. Scott Hutcheson

Office of Historic Preservation

Capitol Annex Building

P.O. Box 44247

Baton Rouge, Louisiana 70804

Dear Mr. Hutcheson:

The New Orleans and St. Louis Districts, U.S. Army Corps of Engineers are presently

conducting research and planning for a project located in southern Louisiana. The name

of the project is "Louisiana Coastal Area, Convey Atchafalaya River Water to Northern

Terrebonne Marches" (LCA-ARNTM). This is a feasibility study, developed out of the

Louisiana Coastal Area Ecosystem Restoration Study of 2004, to explore a large-scale

and long-term restoration project moving fresh water, sediments, and nutrients from the

Atchafalaya River and the Gulf Intracoastal Waterway (GIWW). Although the project is

still in preliminary planning, when it reaches construction phase it has the potential to

impact cultural resources. Therefore, we are contacting you to solicit your comments and

any information you care to provide.

As background, the LCA program, of which ARNTM is a portion, was authorized by

Title VII of the Water Resources Development Act (WRDA) 2007. The authority

includes requirements for comprehensive coastal restoration planning, program

governance, project modification investigations, a Science and Technology program,

restoration project construction, a program for beneficial use of dredged material,

feasibility studies for restoration plan components, and other program elements. The

LCA-ARNTM Study Area (see enclosure) comprises approximately 1000 square miles

(~660,000 acres) in southern Louisiana in the vicinity of the city of Houma in Terrebonne

Parish. The LCA-ARNTM study area fits into the Louisiana coastal Area Ecosystem

Restoration Study Area, which has been identified as the Louisiana coastal region from

Mississippi to Texas. The overall study area is bounded to the west by the Lower

Atchafalaya River, and to the east by the Bayou Lafourche ridge. The study area is

further bounded to the north by the Bayou Black ridge, from the Lower Atchafalaya

River to the city of Houma, and the Gulf Intracoastal Waterway (GIWW), from the city

of Houma to the Bayou Lafourche ridge. The southern boundary of the project was based

on a delineation conducted in 2007 of coastal Louisiana vegetation types. This boundary

identifies the transition between saline and brackish marsh types.

DEPARTMENT OF THE ARMY

ST. LOUIS DISTRICT, CORPS OF ENGINEERS

1222 SPRUCE STREET

ST. LOUIS, MISSOURI 63103-2833

REPLY TO

ATTENTION OF:

835
F-46

A site file and records review by District personnel found that nearly four hundred

prehistoric and historic sites have been identified in the Terrebonne marshes and along

the lobes of the Lafourche-Terrebonne Delta. While the current project is a feasibility

study, the anticipated work product for cultural resources is a synthetic GIS-based dataset

that will provide guidance for cultural resources planning throughout the subsequent

stages of the ecosystem restoration program within the Terrebonne marshes.

We will be keeping you informed regarding the progress of this project as more

concrete plans are developed for construction that may impact cultural resources within

the study area. If you have any questions or comments, please feel free to contact Susan

Malin-Boyce (314-331-8804) at the St. Louis District.

Sincerely,

Michael K. Trimble, Ph.D.

Chief, curation and Archives

Analysis Branch

Enclosure

Barnes

CEMVS-EC-Z

Malin-Boyce

CEMVS-EC-Z

Pulliam

CEMVS-EC-Z

Trimble

CEMVS-EC-Z

836
F-47

June 5, 2009

Engineering and Construction Division

Curation and Archives Analysis Branch

Principal Chief Oscola Clayton M. Sylestine

Alabama Coushatta Tribe of Texas

571 State Park Road 56

Livingston, Texas 77351

Dear Principal Chief Sylestine:

The New Orleans and St. Louis Districts, U.S. Army Corps of Engineers are presently

working together on a project located in southern Louisiana. The St. Louis District is

assisting the New Orleans District with their consultation activities. As part of this

assistance the St. Louis District is sending out information regarding this project.

The name of the project is "Louisiana Coastal Area, Convey Atchafalaya River Water

to Northern Terrebonne Marches" (LCA-ARNTM). The project is located primarily in

Terrebonne Parish with a small portion in Lafourche Parish (see attachment 1). This

project is a feasibility study, developed out of the Louisiana Coastal Area Ecosystem

Restoration Study of 2004, to explore a large-scale and long-term restoration project that

will move fresh water, sediments, and nutrients from the Atchafalaya River and the Gulf

Intracoastal Waterway (GIWW) into the marshes south of the GIWW. Currently, the

feasibility study is limited to literary sources and there are no plans for active

archaeological field surveys at this point of the project.

As background, this project was authorized by Title VII of the Water Resources

Development Act (WRDA) 2007. The authority includes requirements for

comprehensive coastal restoration planning, program governance, project modification

investigations, a Science and Technology program, restoration project construction, a

program for beneficial use of dredged material, feasibility studies for restoration plan

components, and other program elements. The LCA-ARNTM Study Area comprises

approximately 1000 square miles (~660,000 acres) in southern Louisiana in the vicinity

of the city of Houma in Terrebonne Parish. This study area fits into the Louisiana coastal

Area Ecosystem Restoration Study Area, which has been identified as the Louisiana

coastal region from Mississippi to Texas. The overall study area is bounded to the west

by the Lower Atchafalaya River and to the east by the Bayou Lafourche ridge. The study

area is further bounded to the north by the Bayou Black ridge, from the Lower

Atchafalaya River to the city of Houma, and the Gulf Intracoastal Waterway, from the

city of Houma to the Bayou Lafourche ridge. The southern boundary was based on a

2007 delineation of coastal Louisiana vegetation types. This boundary identifies the

transition between saline and brackish marsh types.

DEPARTMENT OF THE ARMY

ST. LOUIS DISTRICT, CORPS OF ENGINEERS

1222 SPRUCE STREET

ST. LOUIS, MISSOURI 63103-2833 REPLY TO

ATTENTION OF:

837
F-48

This study called for a review of archived records and documents to identify any

previously recorded archaeological sites, traditional cultural properties, and or sacred

sites located within the project area. A site file and records review by District personnel

found that nearly four hundred prehistoric and historic sites have been identified and

recorded within the Terrebonne marshes and along the lobes of the LafourcheTerrebonne Delta.

Most Native American traditional cultural properties, and or sacred sites have not

been recorded. These areas cannot be identified without the assistance of the tribes.

Thus we are requesting your assistance in identifying such areas within the project

boundaries. With this information the New Orleans and St. Louis Districts will be better

informed on areas that need to be protected. This information will also allow the New

Orleans and St. Louis Districts to begin consultation early and to look at alternative plans

if sites are in the path of construction. If the project reaches a construction phase it has

the potential to impact cultural resources other than archaeological sites, thus your

assistance in identifying such sites would be of great benefit in protecting areas important

to your tribe. All of the following tribes are being notified regarding this project as

potential interested parties.

Alabama Coushatta Tribe of Texas

Caddo Nation of Oklahoma

Chitimacha Tribe of Louisiana

Choctaw Nation of Oklahoma

Coushatta Tribe of Louisiana

Jena Band of Choctaw

Mississippi band of Choctaw

Quapaw Tribe of Oklahoma

Seminole Nation of Oklahoma

Seminole Tribe of Florida

Tunica-Biloxi Tribe of Louisiana

The St. Louis District will keep you informed regarding the progress of this project as

concrete plans are developed for construction that may impact cultural resources within

the study area. If your tribe would like to be a consulting party to this project to help

delineate cultural resources please contact Roberta L. Hayworth, St. Louis District, by

phone at (314-331-8833) or at the address below by 1 September 2009.

838
F-49

Roberta L. Hayworth

Native American Coordinator

USACE St. Louis District

ATTEN: CEMVS-EC-Z

1222 Spruce Street

St. Louis, Missouri 63103

e-mail: roberta.l.hayworth@usace.army.mil

If you have further questions or need additional information, please contact Ms.

Hayworth, and copy Mr. Gary Demarcay (gary.b.demarcay@usace.army.mil) and Mr.

Mike Swanda (michael.l.swanda@usace.army.mil).

Sincerely,

Michael K. Trimble, Ph.D.

Chief, curation and Archives

Analysis Branch

Attachments

Copy Furnished:

Hayworth

CEMVS-EC-Z

Malin-Boyce

CEMVS-EC-Z

Pulliam

CEMVS-EC-Z

Trimble

CEMVS-EC-Z

839
F-1

840
F-61

841
F-62

March 30, 2010

Regional Planning and

Environmental Division, South

New Orleans Environmental Branch

Mr./Ms. Name, Title

Organization

Address

City, State Zip

Re: Programmatic Agreement regarding the Louisiana Coastal Area Ecosystem

Restoration Plan (LCA Plan), Louisiana.

Dear Mr./Ms. Last Name:

The United States Army Corps of Engineers, New Orleans District (CEMVN), is initiating

consultation to develop a Programmatic Agreement for the Louisiana Coastal Area Ecosystem

Restoration Plan (LCA Plan) pursuant to Section 106 of the National Historic Preservation Act

of 1966, as amended. The LCA Plan is the recommended plan of the Louisiana Coastal Area

(LCA), Louisiana Ecosystem Restoration Study (LCA Study), which was completed in

November 2004 and recommended to the Congress by a Chief of Engineers report dated January

31, 2005. The proposed undertakings of the LCA Plan have the potential to impact historic

properties. We invite the Name of Organization/Person to participate in this consultation.

The LCA Plan calls for a coordinated, feasible solution to the identified critical water

resource problems and opportunities in coastal Louisiana. The 2004 LCA Study included the

following recommendations: 1) five near-term critical restoration features that have some

planning and design already underway; 2) ten additional near-term critical restoration features; 3)

beneficial use of dredged material; 4) authority to initiate studies of modifications to existing

water control structures; 5) science and technology program demonstration projects; 6) science

and technology program; and 7) studies on long-term, large-scale restoration concepts. Section

7006 of the Water Resources Development Act (WRDA) of 2007 includes conditional

authorization for the LCA projects described in the 2004 report. Section 7006(e) of WRDA

2007 requires that an additional feasibility report for six of the ten near-term critical restoration

features identified in the 2004 LCA Study be submitted to the Congress by the Secretary of the

Army on or before December 31, 2010. Additional information can be found on the web at

http://www.mvn.usace.army.mil/environmental/lca.asp. A map showing the 15 critical

restoration features of the LCA Plan is enclosed herein.

DEPARTMENT OF THE ARMY

NEW ORLEANS DISTRICT, CORPS OF ENGINEERS

P.O. BOX 60267

NEW ORLEANS, LOUISIANA 70160-0267

REPLY TO

ATTENTION OF:

842
F-63

-2-

The CEMVN proposes to develop a Programmatic Agreement that will establish Section 106

consultation procedures under the accelerated schedules required by the above authorization.

The goal of this Section 106 consultation is to seek ways to balance the critical need to reverse

the current trend of coastal ecosystem degradation against any historic preservation concerns to

come out in the public interest. These procedures will involve consultation, treatment

approaches, resolution of adverse effects, and mitigation of impacts.

Please notify Rebecca Hill of my staff if the Name of Organization/Person or any other

interested party you may know wishes to participate in this consultation. You can reach her at

the above address or by phone at (504) 862-1474 or by e-mail at Rebecca.Hill@usace.army.mil.

We propose to forward future notices, draft agreements, and other background information to

the consulting parties by email to minimize communication delays and expedite the development

of the Programmatic Agreement for this critical coastal Louisiana ecosystem restoration plan.

Please let me know if this is impractical so that we can make alternative arrangements. The

CEMVN will distribute a draft Programmatic Agreement by email to consulting parties prior to a

teleconference that will be held during the week of April 12, 2010. The proposed date for the

teleconference will be confirmed upon notification of your participation.

Sincerely,

Joan M. Exnicios

Chief, New Orleans Environmental Branch

Enclosure

Swanda

CEMVN-PDR-RN

Exnicios

CEMVN-PDR-R

843
F-64

Interested Parties notified for the LCA Plan Programmatic Agreement:

LOCAL GOVERNMENTS

Ascension Parish

Mr. Tommy Martinez, Parish President

Ascension Parish

208 East Railroad Avenue

Gonzales, LA 70737

Assumption Parish

Mr. Martin S. Triche, Parish President

Assumption Parish Police Jury

P.O. Box 520, 4813 Highway One

Napoleonville, LA 70390

Calcasieu Parish

Mr. Bryan C. Beam, Parish Administrator

Calcasieu Parish Police Jury

1015 Pithon Street, P.O. Box 1583

Lake Charles, LA 70602

Cameron Parish

Ms. Earnestine "Tina" Horn, Parish Administrator

Cameron Parish Police Jury

P.O. Box 1280

Cameron, LA 70631

Iberia Parish

Mr. Ernest Freyou, Parish President

Iberia Parish

300 Iberia Street, Suite 400

New Iberia, LA 70560

Jefferson Parish

Mr. Steve J. Theriot, Parish President

Jefferson Parish

1221 Elmwood Park Boulevard, Suite 1002

Jefferson, LA 70123

Lafourche Parish

Ms. Charlotte A. Randolph, Parish President

Lafourche Parish

402 Green Street, P.O. Drawer 5548

Thibodaux, LA 70302

844
F-65

Livingston Parish

Mr. Mike Grimmer, Parish President

Livingston Parish

P.O. Box 427

Livingston, LA 70754

Orleans Parish

Mr. C. Ray Nagin, Mayor

City of New Orleans

1300 Perdido Street

New Orleans, LA 70112

Plaquemines Parish

Mr. Billy Nungesser, Parish President

Plaquemines Parish

8056 Highway 23, Suite 200

Belle Chasse, LA 70037

St. Bernard Parish

Mr. Craig P. Taffaro, Jr., Parish President

St. Bernard Parish

8201 West Judge Perez Drive

Chalmette, LA 70043

St. Charles Parish

Mr. V.J. St. Pierre, Jr., Parish President

St. Charles Parish

P.O. Box 302, 15045 Highway 18

Hahnville, LA 70057

St. James Parish

Mr. Dale Hymel, Jr., Parish President

St. James Parish

5800 Highway 44

Convent, LA 70723

St. John Baptist Parish

Mr. Pat McTopy, Parish President

St. John Baptist Parish

1801 West Airline Highway

LaPlace, LA 70068

St. Martin Parish

Mr. Guy Cormier, Parish President

St. Martin Parish

301 Port Street, P.O. Box 9

St. Martinville, LA 70582

845
F-66

St. Mary Parish

Honorable Paul P. Naquin, Jr., Parish President

St. Mary Parish

Fifth Floor Courthouse Building

Franklin, LA 70538

St. Tammany Parish

Mr. Kevin Davis, Parish President

St. Tammany Parish

P.O. Box 628

Covington, LA 70434

Tangipahoa Parish

Mr. Gordon Burgess, Parish President

Tangipahoa Parish

P.O. Box 215, 206 East Mulberry Street

Amite, LA 70422

Terrebonne Parish

Honorable Michel Claudet, Parish President

Terrebonne Parish

8026 Main Street, Suite 700

Houma, LA 70360

Vermilion Parish

Mr. Chris Theriot, Parish Administrator

Vermilion Parish Police Jury

100 North State Street, Suite 200

Abbeville, LA 70510

LEVEE DISTRICTS

Atchafalaya Basin Levee District

Mr. John Grezaffi, President

Board of Commissioners

P.O. Box 170

Port Allen, LA 70767

Pontchartrain Levee District

Mr. Steven C. Wilson, President

Board of Commissioners

P.O. Box 426

Lutcher, LA 70071

846
F-67

Lafourche Basin Levee District

Mr. Robert LeBlanc, President

Board of Commissioners

P.O. Box 670

Vacherie, LA 70090

East Jefferson Levee District

Ms. Fran Campbell, Executive Director

203 Plauche Court

Harahan, LA 70123

Orleans Levee District

Mr. Gerard J. Gillen, III, P.E.

Director of Hurricane and Flood Protection

6920 Franklin Ave

New Orleans, LA 70122

West Jefferson Levee District

Mr. Giuseppe Miserendino, Director of Operations

7001 River Road

Marrero, LA 70072

Plaquemines Parish Government

Mr. Billy Nungesser, Parish President

8056 Highway 23, Suite 200

Belle Chasse, LA 70037

Lake Borgne Basin Levee District

Ms. Peggy Sembera, Executive Director

P.O. Box 216

Violet, LA 70092

St. Mary Parish Council

Mr. Paul Naquin, Parish President

Fifth Floor, Courthouse

Franklin, LA 70538

South Lafourche Levee District

Mr. Ronald Callais, President

Board of Commissioners

P.O. Box 426

Galliano, LA 70354

Town of Berwick

Honorable Louis Ratcliff

Mayor of Berwick

P.O. Box 486

Berwick, LA 70342

847
F-68

City of Morgan City

Honorable Tim Matte

Mayor of Morgan City

P.O. Box 1218

Morgan City, LA 70381

Grand Isle Independent Levee District

Mayor David Camardelle, President

Board of Comissioners

P.O. Box 757

Grand Isle, LA 70358

Terrebonne Levee and Conservation District

Mr. Reggie Dupre, Jr., Executive Director

Board of Commissioners

220-A Clendenning Road

Houma, LA 70363

North Lafourche Conservation Levee and Drainage District

Mr. Dwayne Bourgeois

P.O. Drawer 230

Raceland, LA 70394

Southeast Louisiana Flood Protection Authority - East

Mr. Timothy P. Doody, President

East Jefferson, Orleans and Lake Borgne Levee Districts

6508 Spanish Fort Boulevard

New Orleans, LA 70124

Southeast Louisiana Flood Protection Authority - West

Mr. Giuseppe R. Miserendino, C.P.A.

West Jefferson and Algiers Levee Districts

7001 River Road

Marrero, LA 70072

HISTORICAL SOCIETIES

Louisiana Genealogical and Historical Society

Irma Lee Jackson, President

P.O. Box 82060

Baton Rouge, LA 70884

LAGenWeb Project

Edward Hayden, Coordinator

P.O. Box 7165

Pasadena, TX 77508

848
F-69

Ark-La-Tex Genealogical Association, Inc.

Jim Johnson, President

P.O. Box 4463

Shreveport, LA 71134

Canary Islanders Heritage Society of Louisiana

Rose Marie Powell, President

13190 Legacy Court

Baton Rouge, LA 70816

Genealogical Research Society of New Orleans

Sidney J. Mazerat, III, President

P.O. Box 51791

New Orleans, LA 70151

Louisiana Archaeological Society

John H. Guy, Jr., President-Elect

P.O. Box 503, 4105 Main Street

Anacoco, LA 71403

The Louisiana Division of Archaeology

Dr. Charles McGimsey, Director

P.O. Box 44247

Baton Rouge, LA 70804

Southeast Archeological Center

David Morgan, Director

2035 East Paul Dirac Drive, Johnson Building Suite 120

Tallahassee, FL 32310

Louisiana Landmarks Society

Susan Lloyd McClamroch, Pitot House Director

1440 Moss Street

New Orleans, LA 70119

Louisiana Creole Heritage Center

Janet Ravare Colson, Executive Director

Northwestern State University, Box 5675

Natchitoches, LA 71497

Louisiana Historical Association

Mark Fernandez, President

P.O. Box 42808

Lafayette, LA 70504

849
F-70

Louisiana Historical Society

G. Howard Hunter, President

5615 Perrier Street

New Orleans, LA 70115

Foundation for Historical Louisiana

Mark Upton, Chairman

P.O. Box 908

Baton Rouge, LA 70821

Division of Historic Preservation

Nicole Hobson-Morris, Executive Director

1051 North Third Street

Baton Rouge, LA 70804

National Trust for Historic Preservation Southern Office

William Aiken House

456 King Street

Charleston, SC 29403

The Southwest Louisiana Genealogical Society, Inc.

P.O. Box 5652

Lake Charles, LA 70606

Genealogy West

5644 Abbey Drive

New Orleans, LA 70130

Louisiana Roots

105 North Main Street

Marksville, LA 71351

Louisiana Trust for Historic Preservation

Michelle Meche, Executive Director

P.O. Box 1587

Baton Rouge, LA 70821

National Trust for Historic Preservation, New Orleans Field Office

923 Tchoupitoulas Street

New Orleans, LA 70130

Ascension Heritage Association

Pam Gregoire, President

P.O. Box 404

Donaldsonville, LA 70346

850
F-71

East Ascension Genealogical and Historical Society

P.O. Box 1006

Gonzales, LA 70707

Calcasieu Historical Preservation Society

Donna Richard, President

P.O. Box 1214

Lake Charles, LA 70602

Iberia Cultural Resources

924 East Main Street

New Iberia, LA 70560

Jefferson Historical Society of Louisiana

Frank J. Borne, Jr., President

3404 Tolmas Drive

Metairie, LA 70002

Westwego Historical Society

Daniel P. Alario, Sr., President

502 Second Street

Westwego, LA 70094

The Gretna Historical Society

205 Lafayette Street

Gretna, LA 70053

Francaise Comite Louisiana

2717 Massachusetts Street

Metairie, LA 70003

Historical Society of Grand Isle

P.O. Box 275

Grand Isle, LA 70358

Lafourche Heritage Society

P.O. Box 567

Thibodaux, LA 70393

Edward Livingston Historical Association

P.O. Box 67

Livingston, LA 70754

French Settlement Historical Society

P.O. Box 365

French Settlement, LA 70733

851
F-72

The Historic New Orleans Collection

533 Royal Street

New Orleans, LA 70130

The Historic District Landmarks Commission

C. Elliott Perkins, Executive Director

1340 Poydras Street, Suite 1152

New Orleans, LA 70112

Preservation Resource Center

Patricia Gay, Executive Director

923 Tchoupitoulas Street

New Orleans, LA 70130

St. James Historical Society

1988 Jefferson Highway

Lutcher, LA 70071

Los Isleños Heritage and Cultural Society

Dorothy (Dot) L. Benge, President

1345-1347 Bayou Road

St. Bernard, LA 70085

St. Bernard Genealogical Society

P.O. Box 271

Chalmette, LA 70044

River Road Historical Society

Nancy J. Robert, Administrator

P.O. Box 5

Destrehan, LA 70047

German-Acadian Coast Historical and Genealogical Society

P.O. Box 517

Destrehan, LA 70047

The Godchaux-Reserve House Historical Society

P.O. Box 234

Reserve, LA 70084

St. Mary Genealogical and Historical Society

P.O. Box 662

Morgan City, LA 70381

St. Tammany Parish Historical Society

P.O. Box 1251

Mandeville, LA 70470

852
F-73

St. Tammany Genealogy Society

P.O. Box 1904

Covington, LA 70434

Tangipahoa Parish Historical Society

77139 North River Road

Kentwood, LA 70444

Amite Genealogical Club

739 West Oak

Amite, LA 70422

Terrebonne Genealogical Society

Philip Chauvin, President

P.O. Box 20295

Houma, LA 70360

The Terrebonne Historical & Cultural Society, Inc.

Ms. Dale Norred, President

P.O. Box 2095

Houma LA 70361

Vermilion Historical Society

P.O. Box 877

Abbeville, LA 70511

Vermillion Genealogical Society

P.O. Box 117

Abbeville, LA 70511

LOUISIANA STATE RECOGNIZED TRIBES

Adai Caddo Tribe

Rufus Davis, Chairman

4500 Hwy 485

Robeline, LA 71469

Biloxi-Chitimacha Confederation/ Bayou Lafourche Band

Randy Verdun, Chairman

P.O. Box 856

Zachary, LA 70791

Choctaw - Apache Community of Ebarb

John W. Porcell, Chairman

P.O. Box 1428

Zwolle, LA 71486

853
F-74

Clifton Choctaw Tribe

Tom Neal, Chairman

1312 Clifton Road

Gardner, LA 71447

Four Winds Tribe, La. Cherokee Confederacy

Jackie Womack, Principal Chief

P.O. Box 118

Merryville, LA 70653

Point-Au-Chien Tribe

Charles Verdin, Chairman

P.O. Box 416

Montegut, LA 70377

United Houma Nation

Brenda DarDar, Chairwoman

20986 Hwy 1

Golden Meadow, LA 70357

Isle de Jean Charles Band

Albert Naquin, Chief

100 Dennis Street

Montegut, LA 70377

The Louisiana Choctaw Tribe

James D. Rainwater, Chairman

15212-B Hubb Road

Pride, LA 70770

Grand Caillou/Dulac Band

Marlene Foret, Chairwoman

114 Retreat Drive

Bourg, LA 70343

Talimali Band Apalache of Louisiana

Gilmer Bennett

P.O. Box 84

Libuse, LA 71348

Atakapa-Ishak Nation

Michael Amos, Chief

P.O. Box 1532

Lake Charles, LA 70602

854
F-75

Louisiana Choctaw Turtle Tribe

James Greywolf Gil, Chief

379 Sharon Lane

Lake Charles, LA 70611

Chahta Tribe

Elwin Warhorse Gillum, Chief

61357 Dixe Ranch Road

Slidell, LA 70460

Louisiana Intertribal Council

Kevin Billiot, Director

5723 Superior, Suite B-1

Baton Rouge, LA 70816

Louisiana Indian Education Association

Pat Arnould, Director

17114 Grey Birch Drive

Greenwell Springs, LA 70739

Louisiana Indian Heritage Association

Andrea Randazzo, Powwow Chairperson

P.O. Box 1390

Folsom, LA 70437

LOUISIANA REGIONAL AND STATION ARCHAEOLOGISTS

Jeff Girard, Regional Archaeologist

Regional Archaeology Program

School of Social Sciences

Northwestern State University

Natchitoches, LA 71497

Dr. Joe Saunders, Regional Archaeologist

Regional Archaeology Program

Department of Geosciences

The University of Louisiana at Monroe

Monroe, LA 71209

Dr. David Palmer, Regional Archaeologist

Regional Archaeology Program

Department of Sociology and Anthropology

University of Louisiana at Lafayette

Lafayette, LA 70504-0198

855
F-76

Dr. Rob Mann, Regional Archaeologist

Regional Archaeology Program

Department of Geography and Anthropology

227 Howe Russell

Louisiana State University

Baton Rouge, LA 70803

Andrea White, Regional Archaeologist

Department of Anthropology

School of Urban Planning and Regional Studies

University of New Orleans

New Orleans, LA 70148

Dr. Diana Greenlee, Station Archaeologist

Poverty Point State Historic Site

P.O. Box 276

Epps, LA 71237

856
APPENDIX G:

Responses to Comments

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1. Acknowledged. 1

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1. Acknowledged. Comment of support noted. 1

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2. Acknowledged. Slope stability and bankline stability

analyses will be conducted on WD3 during preconstruction engineering and design. Hydraulic, slopestability, and bankline stability analyses will be conductedon WD2 during pre-construction engineering and design.

3. Acknowledged.4. Acknowledged. Analysis conducted in conjunction with

the CWPPRA TE-32a Lake Boudreaux FreshwaterIntroduction Project demonstrated that increasing flow byway of these bayous was not efficient or technicallyfeasible. Therefore, these features were eliminated fromconsideration for the LCA-ARTM study.

5. Acknowledged.6. Acknowledged.

2

3

1

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1. Concur. The use of the term reverse was replaced with

reduce the trend.

2. Concur. Responses to those recommendations have been

added to Section 7.2.1 of the report.

1

2

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3. Concur. Discussion of trends in Penchant Basin flotant

marshes clarified throughout document.

4. Acknowledged. However this information is too detailed

for Executive Summary. This information can be found inChapter 5 and Appendix L.

5. Concur. Updated language in ES 9.6. Concur. Updated language in Sec 15.4.4.7. Concur. Updated language in Sec 2.3.3.8. Concur. Updated language in Sec 2.3.3.9. Concur. An additional figure showing the features in the

north Lake Boudreaux area has been added after thealternatives figures.

10. Concur. Section 3.5.2 modified accordingly.

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11. Non-Concur. There are two identical structures that pass

under Highway 57. CC13 is as stated by the commenterand is located near Bayou Pelton. CS1 passes underHighway 57 on Bayou Butler.

12. Concur. Text modified accordingly.13. Concur. Text modified accordingly.14. Concur. Section 4.2.7.1 modified accordingly.15. Concur. Text modified accordingly.16. Acknowledged. Dredged material will be used beneficially

to the maximum extent practicable. However, due tounknown material and site properties, acreages could not bedetermined. These will be determined in future during preconstruction engineering and design (PED). The results offurther evaluations conducted during PED will be disclosedto the public.

17. Concur. Sections 5.15.10.1.2.1 and 5.15.10.1.2.2 modified

accordingly. Parts of Section 5.15.10.1.2.1 subsequentlymoved to Section 5.15.6 (Navigation).

18. Concur. Text modified accordingly in sections 3.3.2,

3.10.4, and 8.1.

1112131415161718

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19. Concur. Updated language in Sec 8.3.20. Acknowledged.21. This concern is noted and the desired outcome has been

deleted. Vegetation monitoring is still proposed to groundtruth the proposed Landsat imagery.

19

2021

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22. The LCA AM Framework team agrees that these types of

analyses could be valuable. These analyses arecomplicated, but not impossible, for project areas obscuredby vegetation structure. Because Landsat imagery isalready proposed for utilization in the monitoring andadaptive management plan, this additional information canbe easily evaluated relatively economically. If the PDTdetermines this information is necessary, then it can beadded during plan modification during pre-constructionengineering and design.

23. Concur. Utilization of pre- and post-project fishery data

from Louisiana Department of Wildlife and Fisheries isnow included in the monitoring and adaptive managementplan. Expansion of the current LDWF sampling regime isnot proposed at this time. If it is determined, incoordination with LDWF and other resource agencies, thatadditional sampling is needed, it will be considered duringpre-construction engineering and design.

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1. Acknowledged. 1

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2. Acknowledged.3. Acknowledged.4. Acknowledged. Additional projects may need to be

considered in the future based on RSLR, ARTM projectperformance during monitoring, the updated State MasterPlan, Medium and Long-term LCA proposals based on thedata and methods being evaluated by the LCA ScienceBoard and others. The ARTM project is a critical near-termproject to address the immediate needs of the study areaand its critical resources.

5. Concur. Text modified accordingly.

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6. Non-concur. Alternatives were formulated to achieve the

objectives set forth early in the planning process by themulti-agency project delivery team, but these objectivescould not be fully attained through this study alone.Modifying objectives at this stage in the plan formulationprocess would potentially reduce USACE credibility in thisscientific analysis.

7. Concur. However, due to schedule limitations, the

hydraulic and habitat assessment analyses necessary for acomplete sensitivity analysis related to Morganza to theGulf completion schedules cannot be conducted. In lieu ofthis, a sensitivity analysis based on analysis of Alternative7 results (the Alternative involving only the modifiedoperation of the HNC lock complex) was added to Section3.10.4 of the report.

8. Acknowledged. At this time the implications of this project

on the HNC deepening and vice versa are anticipated to benegligible. The HNC deepening would not impact themodified operation since the operation plan is to have thefloodgate closed year-round. Any impacts associated withthe modified operation plan are already discussed in thereport.

9. Concur. HNC lock assumptions clarified throughout

document.

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10. Concur. A description of how the sluice gates would be

operated was added to subsections of section 3.3.2. Theimpacts of this operation were included in the benefitsanalysis, but were not specifically determined.

11. Concur. Discussion of trends in Penchant Basin flotantmarshes clarified throughout document.

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12. Acknowledged.13. Acknowledged.14. Concur.

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1. Concur. A Monitoring and Adaptive Management Plan has

been developed for the project and will facilitateoperational flexibility of project features in coordinationwith regulatory and resource agencies.

2. Concur. All water control structures will be designed

accordingly.

3. Concur. The appropriate Special Use Permits will be

obtained from LDWF prior to construction of the project.

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1. Acknowledged.2. Acknowledged.3. Non-Concur. Due to the similarity of features and

environmental consequences among many of theAlternatives, the descriptions of consequences on a givenresource for Alternatives 3 through 8 frequently refer backto the descriptions of consequences for Alternative 2. Asnecessary, the descriptions of consequences forAlternatives 3 through 8 are expanded beyond those forAlternative 2.

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4. Concur. Text modified accordingly throughout document.5. Concur. Text modified accordingly.6. Acknowledged. Due to close proximity to the study area

this will remain in report.

7. Concur. Text modified accordingly.8. Concur. Descriptions of omitted CWPPRA projects added

to Section 1.5.4.4 accordingly.

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9. Non-Concur. Section 2.3.1 of the report provides a general

discussion of the problems within the project area. Adiscussion of the details of alternatives analysis and relateduncertainty does not belong in this section. A note wasadded to Section 2.3.1 to point the reader to the appropriatesection in the report for a discussion of the uncertainty inrelative sea level rise.

10. Concur. Text modified in Section 2.3.1 accordingly.11. Acknowledged. Flow impacts to the Grand Bayou area are

not identified in the Morganza to the Gulf EIS. LCAARTM operated under the assumption that the final designof all water control structures associated with Morganza tothe Gulf would minimize impacts by mimicking existingflow patterns. Therefore no negative impacts to the GrandBayou area from implementation of Morganza to the Gulfwere anticipated.

12. Concur. Section 3.5.2 modified accordingly.

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13. Concur. Text modified in Section 3.6.1 accordingly.14. Concur. Information on temporary work areas added to

various sections of Chapter 5, EnvironmentalConsequences, accordingly.

15. Acknowledged. Comments from the April 12, 2010 letter

have been addressed and the Monitoring and AdaptiveManagement Plan has been modified accordingly and isincluded as Appendix I.

16. Concur. Text modified accordingly.17. Concur. Due to time constraints, analysis of the RP cannot

be completed. Table 3.10 was replaced with a summarytable showing RSLR, Net AAHU and net acreage valuesfor Alternative 3.

1314151617

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18. Concur. Text changed accordingly.19. Concur. Text added to Sections 5.3.4 and 5.3.5

accordingly.

20. Concur. Table 5.2 added to beginning of Chapter 5

accordingly.

21. Concur. Information on land loss acreages with and

without project implementation added to various sectionsof Chapter 5.

22. Concur. Text modified accordingly.

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23. Concur. Table summarizing impacts of each measure on

fishery access added to Section 5.9. Further analysis oftotal cross-sectional area of pathways available formigration and development of maps indicating areasaffected by restricted movement cannot be completed atthis time due to lack of available data and time constraints.USACE will continue to work closely with NMFS, FWS,and other agencies to ensure that monitoring and adaptivemanagement are effectively utilized to address fisherymovement issues.

24. Acknowledged.25. Concur. Statement added accordingly.26. Concur. Statement added accordingly.

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27. Concur. Table summarizing impacts associated with each

feature added to beginning of Section 5.0 EnvironmentalConsequences and referenced in Section 5.10 EFH.

28. Concur. Text changed accordingly.29. Concur. Discussion of anticipated changes in oyster

production has been expanded in Section 5.15.10.2 of thereport. Maps of anticipated oyster lease and seedproduction locations could not be generated at this time dueto time constraints.

30. Concur. The MAMP has been modified in accordance with

recommendations contained in the April 12, 2010 letter asappropriate. The MAMP has been modified to includeutilization of LDWF fishery monitoring data.

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1. Acknowledged. 1

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2. Acknowledged. During pre-construction engineering and

design the team will sample the area to determine thealignment of the historic Bayou Carencro Channel. TheWD2 channel will follow this alignment and the mineralsoils found in the ridge will be used beneficially to createstable banklines. This channel will re-establish the naturalhydrology and geomorphology of Bayou Carencro whichincludes occasional storm and drought events that mayoccur as part of the natural process. In addition, anynegative impacts can be addressed through monitoring andadaptive management.

3. Acknowledged. This comment is not specific enough to

project features including culverts and specific banklines inthe study area to be properly addressed.

4. Acknowledged. Dredging of Carencro Bayou is included

in the Recommended Plan (feature WD2). Due to themagnitude of development along the length of BayouGrand Caillou and the lack of connection to the GIWW,dredging this waterway was not considered a reasonablealternative. Analysis conducted in conjunction with theCWPPRA TE-32a Lake Boudreaux FreshwaterIntroduction Project demonstrated that increasing flow byway of Bayou Petit Caillou and Bayou Terrebonne was notefficient or technically feasible. Therefore, these featureswere eliminated from consideration for the LCA-ARTMstudy.

5. Acknowledged.

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6. Many of the LCA-ARTM features identified in the Lake

Boudreaux area are, indeed, features pulled directly fromthe CWPPRA TE-32a Project. Since the TE-32a Projectwas not approved for construction funding at the time ofLCA-ARTM plan formulation, it was not considered to bepart of the Future Without Project condition.Implementation of the TE-32a project features byCWPPRA would not negatively impact the LCA-ARTMProject.

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LDEQ Comments regarding US ACOE Proposal to Convey Atchafalaya River Water to the Northern

Terrebonne Marshes

07/05/2010

LDEQ Comments Concerning US Army Corps of Engineers Convey

Atchafalaya River Water to Northern Terrebonne Marshes Study, LA, May

2010

General Comments:

1. LDEQ supports the Corps efforts to restore the wetland habitat of the Northern Terrebonne

Marshes. Overall, the project will be beneficial to the area.

2. The Lake Boudreaux and Grand Bayou Terrebonne marshes are disappearing. The City of

Houma pumps storm water to Lake Boudreaux via Bayou Chauvin. This nutrient and

sediment loading adversely impacts the water quality for Bayou Chauvin and Lake

Boudreaux. However, pumping this storm water to the Northern Terrebonne Marshes instead

of Bayou Chauvin and Lake Boudreaux could have a mutually beneficial impact. The

sediment and nutrient would be placed into the marsh, where it can be assimilated and help

rebuild the marshes. At the same time, the sediment and nutrients would not be placed in

Bayou Chauvin and Lake Boudreaux, where these parameters can cause impairments to the

water quality. Additionally, other pumping stations located within this project area should

also be considered for re-routing to the marshes. The LDEQ has water quality standards for

nutrient assimilation in wetlands and can assist in the effective planning for management of

out-of-channel storm water flows.

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1. Acknowledged. Comment of support noted.2. Acknowledged. That type of project feature would be

outside the authorized scope of conveying AtchafalayaRiver water for this study.

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1. Acknowledged.2. Acknowledged. During pre-construction engineering and

design the team will sample the area to determine thealignment of the historic Bayou Carencro Channel. TheWD2 channel will follow this alignment and the mineralsoils found in the ridge will be used beneficially to createstable banklines. This channel will re-establish the naturalhydrology and geomorphology of Bayou Carencro whichincludes occasional storm and drought events that mayoccur as part of the natural process. Hydraulic analysis willbe conducted to determine saltwater intrusion impacts, andthe design will minimize these impacts. In addition, anynegative impacts can be addressed through monitoring andadaptive management.

12

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3. Acknowledged. This comment is not specific enough to

project features including culverts and specific banklines inthe study area to be properly addressed.

4. Acknowledged. Dredging of Carencro Bayou is included

in the Recommended Plan (feature WD2). Due to themagnitude of development along the length of BayouGrand Caillou and the lack of connection to the GIWW,dredging this waterway was not considered a reasonablealternative. Analysis conducted in conjunction with theCWPPRA TE-32a Lake Boudreaux FreshwaterIntroduction Project demonstrated that increasing flow byway of Bayou Petit Caillou and Bayou Terrebonne was notefficient or technically feasible. Therefore, these featureswere eliminated from consideration for the LCA-ARTMstudy.

5. Acknowledged.6. Many of the LCA-ARTM features identified in the Lake

Boudreaux area are, indeed, features pulled directly fromthe CWPPRA TE-32a Project. Since the TE-32a Projectwas not approved for construction funding at the time ofLCA-ARTM plan formulation, it was not considered to bepart of the Future Without Project condition.Implementation of the TE-32a project features byCWPPRA would not negatively impact the LCA-ARTMProject.

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1. Concur. During pre-construction engineering and design,

impacts and/or construction methods resulting in adischarge will be identified and submitted to LDEQ as partof a LPDES permit application. Discharge will bemanaged in a manner that will either eliminate or reducenon-point discharge in accordance with LPDES permitguidelines. All other applicable permits will be sought andall applicable regulations will be followed.

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1. Acknowledged. While not expressly stated in the

document, the study team was fully aware of the need toavoid stage increases in the upper Penchant Basin and wasaware of the Environmental Assessment for TE-34. TheRP does not increase stages in the upper Penchant Basin asdetailed in Engineering Appendix L, Annex 2, DetailedHydraulic Modeling Studies. Potential errors in land lossanalysis in the upper Penchant Basin due to the presence offloating vegetation are now acknowledged in the report.

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2. Acknowledged. During pre-construction engineering and

design the team will sample the area to determine thealignment of the historic Bayou Carencro Channel. TheWD2 channel will follow this alignment and the mineralsoils found in the ridge will be used beneficially to createstable banklines. This channel will reestablish the naturalhydrology and geomorphology of Bayou Carencro whichincludes occasional storm and drought events that mayoccur as part of the natural process. Hydraulic analysis willbe conducted to determine saltwater intrusion impacts, andthe design will minimize these impacts. In addition, anynegative impacts can be addressed through monitoring andadaptive management.

2

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3. See response to Comment #2 above.

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1. Acknowledged2. Acknowledged. According to ER 1105-2-100, Alternative

2 was identified as the National Ecosystem RestorationPlan. The NER Plan is recommended by USACE and thenon-federal sponsor as representing the best value forecosystem restoration to the Nation. The significant addedcost of Alternative 3 is not justified by the small increase inbenefits.

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1. Acknowledged. During pre-construction engineering and

design the team will sample the area to determine thealignment of the historic Bayou Carencro Channel. TheWD2 channel will follow this alignment and the mineralsoils found in the ridge will be used beneficially to createstable banklines. This channel will reestablish the naturalhydrology and geomorphology of Bayou Carencro whichincludes occasional storm and drought events that mayoccur as part of the natural process. In addition, anynegative impacts can be addressed through monitoring andadaptive management.

2. Acknowledged. The study team chose the planned

alignment because with the current data at hand theproposed channel follows natural waterways. If in fact it isfound that this is not the case or if there is an obvious costand benefit effective alignment alternative, this issue maybe reconsidered in Preconstruction Engineering and Design(PED).

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972
APPENDIX H:

Value Engineering Report

973
Attached is a brief summary of the

Value Engineering Study conducted

for this feasibility investigation. A

complete version of the document is on

file and available at the

US Army Corps of Engineers,

New Orleans District

974
Value Engineering Study Report

Terrebonne Basin Barrier Shoreline Restoration

Multipurpose Operation of Houma Navigation Lock

Convey Atchafalaya River Water to Northern Terrebonne Marshes

CEMVNVE0904

June 2009

Prepared by

Value Management Strategies, Inc.

975
INTRODUCTION

This Value Engineering (VE) Study Report summarizes the events of the VE workshop

conducted May 5  8, 2009 for the U.S. Army Corps of Engineers (USACE), New Orleans

District, by Value Management Strategies, Inc. The subject of the study was the Houma

Navigation Gate Operations Plan, and the Convey Atchafalaya River Water to Northern

Terrebonne Marshes project. This study was conducted at the Feasibility Scoping

Report/Preliminary Draft EIS, an early stage of project development, and as such is the

beginning of plan formulation.

VE STUDY RESULTS

The VE team developed alternative concepts which are intended to assist the USACE in better

formulating plans to carry forward into the next phase of development. These recommendations

are categorized per subject project as well as those that pertain to general plan formulation.

Major findings of the workshop are summarized as follows:

Multipurpose Operation of Houma Navigation Lock

The Houma Navigation Canal (HNC) lock and floodgate were planned over a decade ago. The

possible addition of a yearround significant freshwater flow into the HNC from the proposed

Atchafalaya River Diversion Project would significantly affect the operation of the lock and

floodgate and perhaps even warrant reconsideration of the facility design. The lock and gate

complex will have to balance the impacts to navigation with the necessity of protecting the

interior from tidal surge and salinity. Finally, the potential future global sea level (GSL) rise

impacts what type of facility should be constructed.

Key VE Alternatives identified to address these issues are as follows:

Optimize holistic system by balancing HNC flow rate capacity with gate and lock design and

operation plan  Response: The proposed HNC Gate/Lock complex is a feature of the

authorized Morganza to the Gulf Hurricane Risk Reduction Project (currently undergoing a

Post-Authorization Change (PAC)). While assumptions were made during the feasibility

investigation of the proposed LCA ARTM project, more detailed opportunistic operation

usage of the complex will be looked into. The capacity of the gate and lock is a part of the

Morganza to the Gulf project.

Develop a set of guidelines for when gate will be shut and install monitors and controls to

automatically close gate  Response: An operations plan will be developed. However,

implementation of an automated system may or may not be suitable.

Configure proposed 250foot floodgate such that an additional gate could be added in the

future in order to upgrade to a lock to accommodate a possible higher than expected future

sea level  Response: WRDA 2007 does not provide authority for the LCA ARTM study to

alter the design of the proposed Morganza to the Gulf gate/lock complex on the HNC.

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Issues with this project are that freshwater and sediment has poor delivery to the wetlands due to

1) alterations in natural hydrologic flow (canals, etc.), 2) constrictions in the Gulf Intracoastal

Waterway (GIWW) that reduce freshwater flow to the subunit, and 3) freshwater delivered to the

HNC bypasses adjacent wetlands and delivers to the Gulf of Mexico. The project is also having

to identify where the freshwater needed should be derived from and how it should be delivered to

the areas that need it.

Finally, seasonal differences in the need for freshwater and nutrients, and the locations from

which freshwater can be recruited and distributed, may have conflicting parameters (i.e.,

freshwater is particularly needed during periods of low flow in the rivers).

Key VE alternatives identified to address these issues are as follows:

GIWW Constriction at Houma

o Louisiana Department of Transportation and Development (LADOTD) to build a highrise

bridge and take the tunnel out of service  Response: While removal of the tunnel in

Houma is an alternative, the LADOTD has not prepared any studies or estimates for the

removal of the tunnel and construction of an overpass in its place.

o Install a channel section through the Twin Span bridge  Response: This recommendation

has been utilized.

Address Freshwater Quantity Limitations

o Alter Old River Control Structure to divert more than 70/30 allocation  Response:

determined to beyond the scope of the LCA ARTM study.

o Develop a seasonal freshwater management plan  Response: this effort would require

more time and funding than currently available in the LCA ARTM investigation.

o Install wicker gates on HNC cuts into the marsh  Response: unsure technology for use

in coastal marsh

Address Freshwater Source and Transport

o Use Bayou Lafourche to convey freshwater to the northern Terrebonne marshes 

Response: investigations showed higher salinity gulf water being pulled up Bayou

Lafourche. Assumptions based on other project investigations that Bayou Lafourche

cannot currently carry enough water to reach the GIWW in amounts required to see

tangible benefits.

General/Plan Formulation

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Develop Plan Strategies that account for much higher levels of GSL rise

One issue addressed by the VE team spans all three projects and has ramifications throughout

the Louisiana Coastal Area (LCA) program. All three projects are currently assuming a

minimum amount of relative sea level rise (combination of sea level rise and subsidence).

Currently, work is underway by the USACE, National Oceanic and Atmospheric

Administration (NOAA), and United States Geological Survey (USGS) to investigate the

glacial melt contribution to future GSL rise. Project benefits depend upon habitats maintained

above sea level. Consequently, benefits beyond the 50year planning horizon will be lost if

subsidence and GSL rise exceed the current assumptions. The rate of GSL rise in the future is

currently unknown, but could be much greater than the current assumptions. As such, the

projects should develop specific Plan Strategies that consider the range of possible future GSL

rates.  Response: low, medium, and high sea level rates were employed in the analysis of

ecosystem benefits. At medium and high sea level rise rates, most if not all measures are lost

or the benefits derived are significantly reduced.

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APPENDIX I

ADAPTIVE MANAGEMENT / MONITORING PLAN

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Louisiana Coastal Area (LCA) Program:

Convey Atchafalaya River Water to Northern

Terrebonne Marshes Project

And Multipurpose Operation of

Houma Navigation Lock Feasibility-Level

Monitoring and Adaptive Management Plan

23 July 2010

DRAFT

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TABLE OF CONTENTS

1.0 INTRODUCTION ....................................................................................................... 4

1.1 Authorization for Adaptive Management in the LCA Program .............................. 4

1.2 Procedure for Drafting Adaptive Management Plans for LCA Projects ................. 4

1.3 LCA Communication Structure for Implementation of Adaptive Management ..... 6

2.0 PROJECT ADAPTIVE MANAGEMENT PLANNING ............................................. 7

2.1 Project Goals and Objectives................................................................................... 8

2.2 Management and Restoration Actions..................................................................... 8

2.3 Conceptual Ecological Model for Monitoring and Adaptive Management............. 8

2.4 Sources of Uncertainty............................................................................................. 9

3.0 RATIONALE FOR ADAPTIVE MANAGEMENT................................................... 9

3.1 Adaptive Management Program for the Convey Atchafalaya River Water to

Northern Terrebonne Marshes Project ................................................................... 10

4.0 MONITORING.......................................................................................................... 10

4.1 Rationale for Monitoring ....................................................................................... 11

4.2. Monitoring Plan for the Convey Atchafalaya River Water to Northern Terrebonne

Marshes Project ...................................................................................................... 12

5.0 DATABASE MANAGEMENT ................................................................................ 15

5.1 Description and Location....................................................................................... 16

5.2 Data Storage and Retrieval .................................................................................... 16

5.3 Analysis, Summarizing, and Reporting ................................................................. 16

6.0 ASSESSMENT.......................................................................................................... 16

6.1 Assessment Process ............................................................................................... 17

6.2 Variances and Success ........................................................................................... 17

6.3 Frequency of Assessments..................................................................................... 18

6.4 Documentation and Reporting ............................................................................... 18

7.0 DECISION-MAKING ............................................................................................... 18

7.1 Decision Criteria .................................................................................................... 18

7.2 Potential Adaptive Management Measures ........................................................... 19

7.3 Project Close-Out................................................................................................... 19

8.0 COSTS FOR IMPLEMENTATION OF MONITORING AND ADAPTIVE

MANAGEMENT PROGRAMS....................................................................................... 19

8.1 Costs for Implementation of Monitoring Program ................................................ 19

8.2 Costs for Implementation of Adaptive Management Program.............................. 22

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List of Figures

Figure 1. Set-up Phase of the LCA Adaptive Management Framework.

Figure 2. Implementation Phase of the LCA Adaptive Management Framework.

Figure 3. LCA Communication Structure for Implementation of Adaptive Management.

List of Tables

Table 1. Preliminary Cost Estimates for Implementation of the Monitoring Program for the LCA

Convey Atchafalaya River Water to Northern Terrebonne Marshes Project.

Table 2. Preliminary Cost Estimates for Set-up Implementation of Adaptive Management

Program for the LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes Project.

Table 3. Preliminary Cost Estimates for Implementation of Adaptive Management Program for

the LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes Project.

List of Attachments

Annex 1. LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes Project

Conceptual Ecological Model.

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1.0 INTRODUCTION

This document outlines the feasibility-level monitoring and adaptive management plan for the

Louisiana Coastal Area (LCA) Convey Atchafalaya River Water to Northern Terrebonne

Marshes (ARTM) project. The LCA Adaptive Management Framework Team developed this

monitoring and adaptive management plan with assistance from the Project Delivery Team

(PDT). This plan identifies and describes the monitoring and adaptive management activities

proposed for the Convey Atchafalaya River Water to Northern Terrebonne Marshes project and

estimates their cost and duration. This plan will be further developed in the preconstruction,

engineering, and design (PED) phase as specific design details are made available.

1.1 Authorization for Adaptive Management in the LCA Program

The LCA Ecosystem Restoration Study Chiefs Report (2005) states (for the 15 near-term

features aimed at addressing the critical restoration needs)

the feasibility level of detail decision documents will identify specific sites, scales, and

adaptive management measures, and will optimize features and outputs necessary to achieve the

restoration objectivesto ensure that LCA ecosystem restoration objectives are realized,

monitoring and adaptive management must be a critical element of LCA projects.

Section 7003(a) of Water Resources Development Act of 2007 (WRDA 2007) stipulates:

The Secretary may carry out a program for ecosystem restoration, Louisiana Coastal Area,

Louisiana, substantially in accordance with the report of the Chief of Engineers, dated January

31, 2005..

Additionally, Section 2039 of WRDA 2007 directs the Secretary of the Army to ensure that,

when conducting a feasibility study for a project (or component of a project) for ecosystem

restoration, the recommended project includes a plan for monitoring the success of the ecosystem

restoration. The implementation guidance for Section 2039, in the form of a CECW-PB

Memorandum dated 31 August 2009, also requires that an adaptive management plan be

developed for all ecosystem restoration projects.

At the programmatic level, knowledge gained from monitoring one project can be applied to

other projects. Opportunities for this type of adaptive management are common within the LCA

Ecosystem Restoration Study (USACE 2004), which also builds upon lessons learned in other

related efforts such as the Coastal Wetlands Planning, Protection and Restoration Act

(CWPPRA). Oversight by the LCA Science and Technology (S&T) Program and the LCA

Adaptive Management Planning Team provides the basic structure to ensure that knowledge

gained is effectively shared across programs and projects.

1.2 Procedure for Drafting Adaptive Management Plans for LCA Projects

The U.S. Army Corps of Engineers, Mississippi Valley Division, New Orleans District (USACE

MVN), Louisiana Coastal Protection and Restoration Authority (CPRA), and the LCA S&T

Office collaborated to establish a general framework for adaptive management to be applied to

all LCA projects. The framework for adaptive management is consistent with the previously

mentioned implementation guidance, as well as with the guidance provided by the U.S. Fish and

Wildlife Service (USFWS) and the National Oceanic and Atmospheric Administration's

(NOAA) "Availability of a Final Addendum to the Handbook for Habitat Conservation Planning

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and Incidental Take Permitting Process in Federal Register vol. 65, No. 106 35242. The LCA

adaptive management framework includes both a set-up phase (Figure 1) and an implementation

phase (Figure 2).

Figure 1. Set-up Phase of the LCA Adaptive Management Framework.

Figure 2. Implementation Phase of the LCA Adaptive Management Framework.

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1.3 LCA Communication Structure for Implementation of Adaptive Management

To execute an adaptive management strategy for the LCA Ecosystem Restoration Plan, a

communication Plan, a communication structure has been identified (Figure 3). The structure

establishes clear lines of communication between LCA Program Management, and Adaptive

Management Planning Team, the S&T Program, PDTs and stakeholders. Successful

implementation will require the right resources being coupled at the right time to support the

framework components.

Figure 3. LCA Communication Structure for Implementation of Adaptive Management.

As part of the LCA Program communication structure for implementation of adaptive

management structure (Figure 3), an LCA Adaptive Management Planning Team will be

established. This Team will be led jointly by a Senior Planner from the USACE and a

counterpart from the CPRA. Other team members include USACE and State support staff and

representatives from USFWS, NOAA, Natural Resources Conservation Service (NRCS), and

Louisiana Department of Wildlife and Fisheries (LDWF). These members will be selected on the

basis of their knowledge of ecosystem restoration, coastal Louisiana ecosystems and adaptive

management. Other resources and expertise will be brought in as needed. This team will be

responsible for recommending project and program adaptive management actions to the LCA

Management Team.

The LCA Science and Technology (S&T) Office was established by the USACE and the State of

Louisiana (the non-Federal sponsor) to effectively address coastal ecosystem restoration needs

and to provide a strategy, organizational structure, and process to facilitate integration of science

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and technology into the adaptive management process. Under the Adaptive Management

Framework, there are five primary elements in the LCA S&T Program, and each element differs

in emphasis and requirements. These elements include: (1) Science Information Needs, (2) Data

Acquisition and Monitoring, (3) Modeling, (4) Research, and (5) Data Management and

Reporting (Assessment).

Under the LCA S&T Office, an Assessment Team will be established. This team will be led by

the S&T Director and a representative of the U.S. Geological Survey (USGS) who will also

serve as direct liaisons between the S&T Assessment Team and the LCA Adaptive Management

Planning Team. Other members will be identified from Federal and State agencies.

Responsibilities of this team include analysis and reporting of data to the LCA Adaptive

Management Planning Team and the LCA Program Management Team.

2.0 PROJECT ADAPTIVE MANAGEMENT PLANNING

Specific LCA PDTs assisted the LCA Adaptive Management Framework Team in developing

the monitoring and adaptive management plan for each specific project. The members of the this

Adaptive Management Framework Team for this project were Tomma Barnes, USACE-MVN;

Steve Bartell, E2 Consulting Engineers; Laura Brandt, U.S. Fish and Wildlife Service; Craig

Fischenich, USACE/Engineer Research and Development Center;, Barbara Kleiss, USACE

Mississippi Valley Division; Carol Parsons Richards, CPRA; Greg Steyer, USGS National

Wetlands Research Center; and John Troutman, CPRA.

The resulting adaptive management plan for the Convey Atchafalaya River Water to Northern

Terrebonne Marshes project describes and justifies whether adaptive management is needed in

relation to the recommended plan (RP) identified in the feasibility study. The plan also identifies

how adaptive management would be conducted for the project and who would be responsible for

this project-specific adaptive management program. The developed plan outlines how the results

of the project-specific monitoring program would be used to adaptively manage the project,

including specification of conditions that will define project success.

This Adaptive Management Plan for this project reflects a level of detail consistent with the

project Feasibility Study. The primary intent was to develop monitoring and adaptive

management actions appropriate for the projects restoration goals and objectives. The specified

management actions permit estimation of the adaptive management program costs and duration

for the project.

The following adaptive management plan section (1) identifies the restoration goals and

objectives identified for the Convey Atchafalaya River Water to Northern Terrebonne Marshes

project, (2) outlines management actions that can be undertaken to achieve the project goals and

objectives, (3) presents a conceptual ecological model that relates management actions to desired

project outcomes, and (4) lists sources of uncertainty that would recommend the use of adaptive

management for this project. Subsequent sections describe monitoring, data management,

assessment, decision-making, and implementation costs.

The level of detail in this plan is based on currently available data and information developed

during plan formulation as part of the feasibility study. Uncertainties remain concerning the

exact project features, monitoring elements, and adaptive management opportunities.

Components of the monitoring and adaptive management plan, including costs, were similarly

estimated using currently available information. Uncertainties will be addressed in the

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preconstruction engineering and design (PED) phase, and a detailed monitoring and adaptive

management plan, including a detailed cost breakdown, will be drafted as a component of the

design document.

2.1 Project Goals and Objectives

During initial stages of project development, the Project Delivery Team, with stakeholder input,

developed restoration goals and objectives to be achieved by the ARTM project. These goals and

objectives were subsequently refined through interactions with the LCA Adaptive Management

Framework Team. The overarching goal of this project is to reduce the current trend of

degradation of the Terrebonne marshes, so as to contribute towards achieving and sustaining a

coastal ecosystem that can support and protect the environment, economy, and culture of

southern Louisiana and thus the Nation. The specific restoration project objectives for the

Convey Atchafalaya River Water to Northern Terrebonne Marshes project are to:

 Prevent, reduce, and/or reverse future wetland loss

 Achieve and maintain characteristics of sustainable marsh hydrology

 Reduce salinity levels in the project area

 Increase sediment and nutrient load to surrounding wetlands

 Increase residence time of fresh water

 Sustain productive fish and wildlife habitat

2.2 Management and Restoration Actions

The PDT performed a thorough plan formulation process to identify potential management

measures and restoration actions that address the project objectives. Many alternatives were

considered, evaluated, and screened in producing a final array of alternatives. The PDT

subsequently identified a recommended plan (RP).

The RP is the NER Alternative, Alternative #2, which involves construction of 56 structures and

other water management features in an effort to holistically address the declining health of the

Terrebonne Marshes ecosystem. This alternative redistributes existing freshwater to benefit

Terrebonne marshes using a variety of measures, including elimination of GIWW constrictions.

Additionally, measures are proposed that restrict, increase, and control water in each of the three

subunits. In the western portion of the study area (Bayou Penchant), dredging, a sediment plug,

and a weir are proposed. In the central portion of the study area (Lake Boudreaux), culverts,

levees, dredging, marsh terraces and berms, sediment plugs, modified operation of the future

HNC (Houma Navigation Canal) lock complex, and a large sluice gated box culvert are

proposed. In the eastern portion of the study area (Grand Bayou), culverts, dredging, gaps in

canal spoil banks, marsh berms, sediment plugs, and removal of a weir and soil plug are

proposed.

2.3 Conceptual Ecological Model for Monitoring and Adaptive Management

As part of the planning process, members of the ARTM PDT developed a conceptual ecological

model to represent current understanding of ecosystem structure and function in the project area,

identify performance measures, and help select parameters for monitoring (Annex 1). The model

illustrates the effects of important natural and anthropogenic activities that result in different

ecological stressors on the system. The effects of concern can be measured for selected

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performance measures defined as specific physical, chemical, and biological attributes of the

system.

2.4 Sources of Uncertainty

Adaptive management provides a coherent process for making decisions in the face of

uncertainty. Scientific uncertainties and technological challenges are inherent with any largescale ecosystem restoration project. Below is a list of uncertainties associated with restoration of

the coastal wetland systems included in the Convey Atchafalaya River Water to Northern

Terrebonne Marshes project.

 Ability of the hydrologic model to predict project impacts/benefits

 Ability of Wetland Value Assessment (WVA) model to predict project impacts/benefits

 Ability of SAND2 (Boustany-ERDC model) to predict impacts/benefits of increases and

decreases in freshwater inputs.

 Elevations/bathymetry throughout project area

 Correct engineering and design to address project objectives

 Correct operational regime to achieve project objectives

Potential climate change issues, such as sea level rise, in addition to regional subsidence rates are

significant scientific uncertainties for all LCA projects. These issues were incorporated in the

plan formulation process and will be monitored by gathering data on water levels, salinities, and

land elevation. These data will inform adaptive management actions, but future climate change

projections remain highly uncertain at this time.

3.0 RATIONALE FOR ADAPTIVE MANAGEMENT

The primary incentive for implementing an adaptive management program is to increase the

likelihood of achieving desired project outcomes given the identified uncertainties. All projects

face uncertainties with the principal sources of uncertainty including (1) incomplete description

and understanding of relevant ecosystem structure and function, (2) imprecise relationships

between project management actions and corresponding outcomes, (3) engineering challenges in

implementing project alternatives, and (4) ambiguous management and decision-making

processes.

Given these uncertainties, adaptive management provides an organized, coherent, and

documented process that suggests management actions in relation to measured project

performance compared to desired project outcomes. In the case of the Convey Atchafalaya River

Water to Northern Terrebonne Marshes project, the adaptive management program will use the

results of continued project monitoring to manage the project in order to achieve the previously

stated project goals and objectives. Adaptive management establishes the critical feedback of

information from among project monitoring to inform project management and promote learning

through reduced uncertainty.

Several questions were considered to determine if adaptive management should be applied to the

Convey Atchafalaya River Water to Northern Terrebonne Marshes project:

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1) Are the ecosystems to be restored sufficiently understood in terms of hydrology and

ecology, and can project outcomes be accurately predicted given recognized natural and

anthropogenic stressors?

2) Can the most effective project design and operation to achieve project goals and

objectives be readily identified?

3) Are the measures of this restoration projects performance well understood and agreed

upon by all parties?

4) Can project management actions be adjusted in relation to monitoring results?

A NO answer to questions 1-3 and a YES answer to question 4 qualifies the project as a

candidate that could benefit from adaptive management. The Framework Team and the PDT

decided that the project meets these qualifications, and, therefore, is a candidate for adaptive

management.

For this project, there are a number of uncertainties associated with ecosystem function and how

the ecosystem components of interest will respond to the restoration project. In addition, there

are associated uncertainties about the best design and operation for the project. Using an adaptive

management approach during project planning provided a mechanism for building flexibility into

project design and for providing new knowledge to better define anticipated ecological

responses. This also enabled better selection of appropriate design and operating scenarios to

meet the project objectives. Additionally, an adaptive management approach will help define

project success and identify outcomes that should realistically be expected for the project.

3.1 Adaptive Management Program for the Convey Atchafalaya River Water to Northern

Terrebonne Marshes Project

An Adaptive Management Program for the Convey Atchafalaya River Water to Northern

Terrebonne Marshes project is needed to ensure proper implementation of adaptive management.

The Program will also facilitate coordination of projects within the LCA Program and

coordination among PDTs, the LCA S&T, and LCA Program Management. The LCA Adaptive

Management Planning Team will lead all LCA project and program adaptive management

recommendations and actions. This team is responsible for ensuring that monitoring data and

assessments are properly used in the adaptive management decision making process. If this team

determines that adaptive management actions are needed, the team will coordinate a path

forward with project planners and project managers. Other PDT members may be solicited as

needed; for instance, if the adaptive management measure is operational, Operations and

Hydraulics representatives might be asked to participate.

The LCA Adaptive Management Planning Team is also responsible for project documentation,

reporting, and external communication. Tables 2 and 3 list the cost estimates for these adaptive

management activities.

4.0 MONITORING

Independent of adaptive management, an effective monitoring program will be required to

determine if the project outcomes are consistent with original project goals and objectives. The

power of a monitoring program developed to support adaptive management lies in the

establishment of feedback between continued project monitoring and corresponding project

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management. A carefully designed monitoring program is a central component of the ARTM

adaptive management program.

4.1 Rationale for Monitoring

Monitoring must be closely integrated with all other LCA adaptive management components

because it is the key to the evaluation and learning components of adaptive management. Project

and system level objectives must be identified to determine appropriate indicators to monitor. In

order to be effective, monitoring designs must be able to distinguish between ecosystem

responses that result from project implementation (i.e., management actions) and natural

ecosystem variability. In coastal Louisiana, there are many existing restoration and protection

projects already constructed, and many more are being planned under different authorizations

and programs. In combination, these projects will ultimately influence much of coastal

Louisiana. Monitoring must therefore be conducted across a range of carefully selected scales to

assess short-term project performance and to characterize longer-term, system-wide trends and

conditions.

Achieving monitoring objectives will require monitoring that focuses on different spatial and

temporal scales. Spatially, a project might achieve local objectives, but have little or no

measurable effect at larger scales. Temporally, monitoring designs need to consider the amount

of time it could take for slowly changing ecological variables to respond to management actions.

Additionally, monitoring should be designed to measure the persistence of near-term effects.

Larger-scale effects will generally take longer to develop and longer to detect than more

localized effects.

Monitoring for large scale effects can be more difficult than monitoring for local effects because

the ecological linkages become more complicated as factors outside project boundaries influence

processes and biota that affect desired project outcomes. The benefits of improved habitat in one

location may be counteracted by degradation at another location, thus showing no overall benefit

at large scales. In addition, monitoring at large scales can involve changes in underlying

conditions over time or space and be very labor intensive. When possible, specific monitoring

and large scale information needs should be interrelated. In some cases, large scale monitoring

may be just an extension of local monitoring in space and time, but it may also involve designs

and procedures that are separate from site specific monitoring and extend beyond the purview of

the project teams.

When possible, specific monitoring and large scale information needs should be integrated with

existing monitoring efforts that are underway in coastal Louisiana. For example, the CWPPRA

program has been monitoring restoration projects in coastal Louisiana since 1990 (Steyer and

Stewart 1992, Steyer et al. 1995). The monitoring program incorporates a system-level wetland

assessment component called the Coastwide Reference Monitoring System (CRMS-Wetlands,

Steyer et al. 2003). CRMS-Wetlands provide system-wide performance measures that are

evaluated to help determine the cumulative effects of restoration projects in coastal Louisiana.

LCA monitoring plans will incorporate existing monitoring networks to the extent practicable

and participate in the implementation of CRMS-Wetlands. Such participation can maintain the

data consistencies necessary to conduct project and programmatic adaptive management.

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4.2. Monitoring Plan for the Convey Atchafalaya River Water to Northern Terrebonne

Marshes Project

According to the CECW-PB Memo dated 31 August 2009, Monitoring includes the systemic

collection and analysis of data that provides information useful for assessing project

performance, determining whether ecological success has been achieved, or whether adaptive

management may be needed to attain project benefits. The following discussion outlines key

components of a monitoring plan that will support the LCA ARTM project Adaptive

Management Program.

The plan identifies performance measures along with desired outcomes (i.e. targets) in relation to

specific project goals and objectives. A performance measure includes specific feature(s) to be

monitored to determine project performance. In addition, if applicable, a risk endpoint was

identified. Risk endpoints measure undesirable outcomes of a management or restoration action.

A monitoring design was established to determine if the desired outcome or risk endpoint is met.

Upon completion of the ARTM project, monitoring for ecological success will be initiated and

will continue until ecological success is achieved, as defined by the project-specific objectives.

This monitoring plan includes the minimum monitoring actions to evaluate success. Although

the law allows for a ten-year cost-shared monitoring plan, ten years of monitoring may not be

required. Once ecological success has been achieved, which may occur in less than ten years

post-construction, no further monitoring will be performed. If success cannot be determined

within that ten-year period of monitoring, any additional monitoring will be a non-Federal

responsibility. This plan estimated monitoring costs for a period of ten years because that is the

maximum allowed federal contribution to monitoring. As soon as ecological success is achieved,

monitoring will cease.

Additional monitoring is identified as supporting information needs that will help to further

understand and corroborate project effects.

Objective 1:

Performance Measure 1: habitat and land:water classification

Prevent habitat conversion and reduce and/or reverse future wetland loss

Desired Outcome: Reduce the rate of land loss (10 year post-construction trend) compared to

the pre-project condition excluding storm events (1985  2012)

Monitoring Design: Habitats will be classified using Landsat TM scenes collected in two preconstruction, 5 construction and 10 post-project construction years and Digital Orthophoto

Quadrangles for three construction and two post-project construction years, as well as any

available field data in the study area to assess land:water trends and habitat distribution.

Monitoring Design: For ground-truthing of Landsat imagery, permanent vegetation monitoring

stations will be established at 24 locations for assessing project area vegetation communities, and

sampled annually. These stations will be monitored 2 years during PED, 5 years during

construction, and 10 years post-construction.

Objective 2:

Performance Measure 2: Depth, duration and frequency of marsh flooding

Achieve and maintain characteristics of sustainable marsh hydrology.

Desired Outcome: Maintain marsh hydrology in range of conditions that support sustainable

fresh, intermediate and brackish marsh

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Monitoring Design: Marsh hydrology will be assessed at 24 stations within the project area and

additional hydrologic stations located in marshes adjacent to Bayou Copasaw, Minors Canal,

Houma Navigational Canal, and Grand Bayou. The need for additional stations will be

determined during pre-construction engineering and design.

Desired Outcome: Maintain hydrology that matches the predicted salinity, temperature,

discharge and flooding characteristics from modeling of selected plan at particular points in time

Supporting Information Need: Salinity, temperature, discharge (velocity and cross-channel

profile), conductivity, turbidity, pH, and water surface elevation

Monitoring Design: The water gauging network (12 stations) that was established for model

development will continue to be monitored during two years during pre-construction, 5 years

during construction and 10 years post-project construction.

Objective 3:

Performance Measure 3: Pore water and surface salinity

Reduce salinity levels in project area

Desired Outcome: Maintain range of variability in salinities at desired locations that will be

identified from modeling output from recommended plan to maintain baseline vegetation

community types.

Monitoring Design: Marsh salinity will be assessed at 24 stations within the project area and

additional hydrologic stations located in marshes adjacent to Bayou Copasaw, Minors Canal,

Houma Navigation Canal, and Grand Bayou, as needed. The need for additional stations will be

determined during pre-construction engineering and design.

Objective 4:

Performance Measure 4: Elevation and accretion

Increase sediment and nutrient load to surrounding wetlands

Desired Outcome: Maintain marsh elevation within tidal frame (relative sea level rise = 0 cm

yr-1).

Monitoring Design: Marsh elevation and accretion will be assessed at 24 stations within the

project area and at additional hydrologic and salinity stations located in marshes adjacent to

Bayou Copasaw, Minors Canal, Houma Navigation Canal, and Grand Bayou, as needed. The

need for additional stations will be determined during pre-construction engineering and design.

Supporting Information Need: Total suspended sediment and macro nutrients

Desired Outcome: Increase sediment and nutrient load

Monitoring Design: Collection of total suspended sediment and nutrients (total nitrogen, nitrate

+ nitrite, total phosphorus) will be used to evaluate change compared to existing conditions using

a subset of the water and salinity gauging network (12 stations) in proximity to Bayou Copasaw,

Minors Canal, Houma Navigation Canal and Grand Bayou.

Objective 5:

Performance Measure: Fish population data

Sustain productive fish and wildlife habitat

Desired Outcome: Sustain current levels of productive fish and wildlife habitat after project

construction

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Monitoring Design: Pre- and post-project data collected by LDWF will be utilized to determine

status and trends of fishery populations in the project area. Assessments utilizing this data will

be performed as long as data are made available. Expansion of the current LDWF sampling

regime is not proposed at this time. If it is determined, in coordination with LDWF and other

resource agencies, that additional sampling is needed, it will be considered during preconstruction engineering and design.

4.2.1 Monitoring Procedures

The following monitoring procedures will provide the information necessary to evaluate the

previously identified project objectives for the Convey Atchafalaya River Water to Northern

Terrebonne Marshes project. Unless otherwise stated, monitoring will begin during PED for two

years, continue for 5 years during construction, and continue for another 10 years postconstruction.

Land:Water and Habitat Classification: Land:water and habitat summaries will be performed

on classified Landsat TM scenes for 1985, 1987, 1990, 1998, 1999, 2001, 2002, 2004, 2005,

2006, 2008, 2009, 2010, 2011, and 2012 in the project area. Linear regression will be used to

calculate land change trends based on those years, excluding anomalous data. Post-project trends

calculated from Landsat TM scenes classified annually will be compared to the pre-project

trends to determine whether conversion of land to open water is being reduced in the project

area. Digital Orthophoto Quarter Quadrangles (DOQQ) of the project area will need to be flown

and habitat analysis completed to capture land cover for one pre-construction and two postconstruction years.

Channel Hydrology: Continuous salinity, temperature, velocity and water surface elevation

measurements will be conducted at 12 locations along the GIWW, Bayou Copasaw, Minors

Canal, Houma Navigation Canal, Bayou Grand Caillou, Cutoff Canal and Grand Bayou.

Discharge will be measured at these stations using velocity and the channels cross-sectional area.

Measurements will be taken at the mouth and downstream of the mouth of each bayou/canal.

Stations will be serviced and data downloaded quarterly or on an as-needed basis.

Marsh Hydrology: To determine whether sustainable marsh hydrology is being maintained in

the project area, water levels in marshes adjacent to flow pathways will be measured hourly with

datasondes at 24 stations within the project area. Each water level gauge will be surveyed

relative to the top of a rod-surface elevation table (RSET) to NAVD88 and will be serviced

approximately 9 times per year. Duration and frequency of flooding will be calculated using

water levels along with the average elevation of the marsh surface.

Water Quality: Measuring and monitoring various water quality parameters, including salinity,

nutrients, conductivity, turbidity, pH, and total suspended solids (TSS) will indicate whether

riverine inputs are impacting water quality in the project area. Monitoring these parameters will

document the water quality of the diverted water. To determine if riverine inputs are flushing

high salinity waters from the project area, the concentration of salt in surface water will be

measured hourly at hydrology locations and discretely by using a porewater sipper device when

sondes are serviced (Folse et al. 2008). Synoptic measurements of nutrients (total nitrogen,

Nitrate+Nitrite, total phosphorus) and total suspended solids will be taken 6 to 9 times per year at

a subset of the water and salinity gauging network in proximity to Bayou Copasaw, Minors

Canal, Houma Navigation Canal and Grand Bayou according to methods described in Day et al.

(2001) and Edwards (1999). Duration of this sampling schedule will be dependent upon final

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project design and operations. Water samples will be collected in 500-mL acid-washed

polyethylene bottles, stored on ice and taken to a laboratory for processing. Within 24 hrs, 60 mL

from each water sample will be filtered through pre-rinsed 25-mm 0.45-μm Millipore filters.

Samples and filters will be frozen until analyzed within one month of collection. Nitrate and

nitrite will be determined separately using automated cadmium reduction method, ammonium by

automated phenate method and phosphate by automated ascorbic acid reduction method

(Standard Methods 1992). Suspended solids will be sampled at points in the center, left and right

of the channel cross-section with a depth-integrated sampler.

Vegetation: Vegetation sampling will occur at the 24 marsh hydrology stations and begin in

PED for 2 years, continue for 5 years during construction, and for 10 years post-construction.

Sampling will occur annually between August and October at each site, and will consist of

sampling ten replicate 2-m x 2-m stations located along a transect within a 200-m x 200-m

square.

Species composition and percent cover for each station will be determined using visual estimates

of cover following the Braun-Blanquet cover scale (Mueller-Dombois and Ellenburg 1974). The

species composition data obtained from vegetation sampling will be used as a means for groundtruthing the land:water and habitat classifications.

Sediment Accretion and Elevation: Sediment accretion and elevation will be assessed at the 24

marsh hydrology stations semi-annually, and begin in PED for 2 years, continue for 5 years

during construction, and for 10 years post-construction. Sediment elevation within the project

area will be measured over time by using the rod-surface elevation table (RSET) technique

which is described in Folse et al. (2008) and references therein. The RSET allows for precise,

repeated measurements of the soil elevation. Marker horizons consisting of feldspar clay will be

used to determine vertical accretion/loss within the project area (Folse et al. 2008).

Fisheries: Monitoring procedures for fisheries status and trends monitoring will follow

established LDWF protocols.

4.2.2 2 Use of Monitoring Results and Analyses

Project monitoring is the responsibility of the CPRA and the USACE. However, because of the

need to integrate monitoring for programmatic adaptive management, extensive agency

coordination is required. A monitoring workgroup, led by the LCA S&T Program and the USGS,

will be responsible for ensuring that project-specific monitoring plans are technically competent

and appropriately integrated within a system-wide assessment and monitoring plan (SWAMP).

The results of the monitoring program will be communicated to an Assessment Team (AT) that

will use the information to assess system responses to management, evaluate overall project

performance, construct project report cards, and recommend modifications (i.e., adaptation) of

the Convey Atchafalaya River Water to Northern Terrebonne Marshes project as appropriate.

5.0 DATABASE MANAGEMENT

Database management is an important component of the monitoring plan and the overall

adaptive management program. Data collected as part of the monitoring and adaptive

management plans for the LCA projects will be archived as prescribed in the LCA Data

Management Strategic Plan developed for the LCA S&T Office, and further developed by the

LCA S&T Data Management Working Group.

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Data standards, quality assurance and quality control procedures and metadata standards will be

prescribed by the LCA S&T Data Management Working Group. Data collected for LCA with

similar data types and collection frequencies as those data collected under the CRMS program

will be managed by the Louisiana Strategic Online Natural Resources Information System

(SONRIS). Pre-existing standard operating procedures built for SONRIS cover issues such as

data upload process and format, quality assurance/quality control, and public data release.

Storage of all other LCA collected data (spatial or non-spatial) will be handled by the LCA

project-specific data libraries on LCA.GOV.

Where applicable, Open Geospatial Consortium standards will be used to facilitate data sharing

among interested parties. Data analysis and reporting responsibilities will be shared between

project assessment and adaptive management efforts in order to provide ARTM project reports

for the LCA Program Management Team.

5.1 Description and Location

The data management plan should identify the computing hardware and any specialized or

custom software used in data management for an adaptive management program. Opportunities

exist to develop either a centralized or distributed data management system. With input from the

LCA Adaptive Management Planning Team, the data managers should determine which

approach best suits the needs of the overall adaptive management program.

Individuals with responsibility for data management activities (data managers) in support of an

adaptive management program should be identified. The data managers should collaborate with

the Adaptive Management Planning Team in developing a data management plan to support the

adaptive management program. The data management plan should be incorporated into the

overall program adaptive management plan  either in the main body of the adaptive

management plan or as an appendix.

5.2 Data Storage and Retrieval

Data standards, quality assurance and quality control procedures and metadata standards will be

prescribed by the Data Management Working Group, and will be complementary with the

CRMS-Wetlands program and SONRIS database. Data will be served using a map services tool,

similar to that currently employed by the CRMS-Wetlands project.

5.3 Analysis, Summarizing, and Reporting

Data analysis and reporting responsibilities will be shared between project and programmatic

adaptive management efforts in order to provide reports for the ARTM Assessment Team,

project managers, and decision-makers.

6.0 ASSESSMENT

The assessment phase of the framework describes the process by which the results of the

monitoring efforts will be compared to the desired project performance measures and/or

acceptable risk endpoints (i.e., decision criteria) that reflect the goals and objectives of the

management or restoration action. The assessment process addresses the frequency and timing

for comparison of monitoring results to the selected measures and endpoints. The nature and

format (e.g., qualitative, quantitative) of these comparisons are defined as part of this phase. The

resulting methods for assessment should be documented as part of the overall adaptive

management plan.

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The results of the ARTM project monitoring program will be regularly assessed in relation to the

desired project outcomes as described by the previously specified project performance measures.

This assessment process continually measures the progress of the project in relation to the stated

project goals and objectives and is critical to the project adaptive management program. The

assessments will continue through the life of the project or until it is decided that the project has

successfully achieved its goals and objectives.

6.1 Assessment Process

The Assessment Team assigned to the ARTM project will identify a combination of qualitative

(i.e., professional judgment) and quantitative methods for comparing the values of the

performance measures produced by monitoring with the selected values of these measures that

define criteria for evaluating project effectiveness.

Appropriate statistical comparisons (e.g., hypothesis testing, ANOVA, multivariate methods,

etc.) will be used to summarize monitoring data as they are obtained and compare these data

summaries with the project decision criteria. These continued assessments will be documented as

part of the project reporting and data management system.

6.2 Variances and Success

The project Assessment Team will collaborate with project managers and decision-makers to

define magnitudes of difference (e.g., statistical differences, significance levels) between the

values of monitored performance measures and the desired values (i.e., decision criteria) that will

constitute variances. Meaningful comparisons between monitoring results and desired

performance will require characterization of historical and current spatial-temporal variability

that define baseline conditions. Variances (or their absence) will be used to recommend adaptive

management actions, including (1) continuation of the project without modification, (2)

modification of the project within original design specifications, (3) development of new

alternatives, or (4) termination of operation of the ARTM project.

Conceptual models have been developed for each project describing the linkages between

stressors and performance measures. The assessments will help determine if the observed

responses are linked to the project. Each project has been formulated to address as many system

stressors as feasible. If the stressors targeted by the project have changed and the performance

measure has not, the linkages in the conceptual model should be examined to determine what

other factors may be influencing the performance measure response.

The assessments will also determine if the responses are undesirable (e.g., are moving away from

restoration goals) and if the responses have met the success criteria for the project. If

performance measures are not responding as desired because the stressor has not changed

enough in the desired direction, then recommendations should be made concerning modifications

to the project. If the stressor has changed as expected/desired and the performance measure has

not, additional research may be necessary to understand why.

From a system-wide perspective, scientific and technical information would be generated from

the implementation of a systemwide monitoring effort. Information generated from this effort

should be linked to evaluating LCA performance and system response. From a project-level

perspective, monitoring plans should be designed to inform adaptive management decision

making by providing monitoring data that are relevant to addressing uncertainty.

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Similarly, for given multiple performance measures and corresponding monitoring results, the

Assessment Team will determine the number and magnitude of variances within a single

assessment that will be required to recommend modifications to the project.

6.3 Frequency of Assessments

Ideally, the frequency of assessments for the ARTM project would be determined by the relevant

ecological scales of each performance measure. The projects technical support staff will identify

for each performance measure the appropriate timescale for assessment. The project should have

a combination of short-, medium-, and long-term performance measures. Assessments should be

performed at a five year interval at a minimum; however, depending on the timescale of expected

responses of the specific measure and frequency of data collection, it may be determined during

PED that more frequent reporting may be necessary.

6.4 Documentation and Reporting

The Assessment Team will document each of the performed assessments and communicate the

results of its deliberations to the managers and decision-makers designated for the ARTM

project. The Assessment Team will work with the project monitoring team and monitoring

workgroup to produce periodic reports that will measure progress towards project goals and

objectives as characterized by the selected performance measures. The results of the assessments

will be communicated regularly to the project managers and decision-makers.

7.0 DECISION-MAKING

Adaptive management is distinguished from more traditional monitoring in part through

implementation of an organized, coherent, and documented decision process. For the Convey

Atchafalaya River Water to Northern Terrebonne Marshes Adaptive Management program, the

decision process includes (1) anticipation of the kinds of management decisions that are possible

within the original project design, (2) specification of values of performance measures that will

be used as decision criteria, (3) establishment of a consensus approach to decision-making, and

(4) a mechanism to document, report, and archive decisions made during the timeframe of the

Adaptive Management Program.

7.1 Decision Criteria

Decision criteria, also referred to as adaptive management triggers, are used to determine if and

when adaptive management opportunities should be implemented. These criteria are usually

ranges of expected and/or desirable outcomes. They can be qualitative or quantitative based on

the nature of the performance measure and the level of information necessary to make a decision.

Desired outcomes can be based on reference sites, predicted values, or comparison to historic

conditions. Specific decision criteria will be developed during the pre-construction engineering

and design phase of the project.

To meaningfully manage these parameters, hydraulic models may need to be revisited and

recalibrated based on field data and observations prior to change in management of a project.

Additional modeling or experimental efforts might be required to understand and manage

observed biotic responses.

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7.2 Potential Adaptive Management Measures

The project report card, drafted by the Assessment Team, will be used to evaluate project status

and adaptive management needs. The Assessment Team may submit recommendations for

adaptive management actions to the Adaptive Management Planning Team. The Adaptive

Management Planning Team will investigate and further refine adaptive management

recommendations and present them to the Program Management Team. Some potential adaptive

management actions for this project may include marsh creation, terracing, canal modification,

gate aperture controls at water control structures, spoil bank gapping, or additional culverts,

shoreline protection features, and modifications to the Houma Navigation Canal Lock Complex.

7.3 Project Close-Out

Close-out of the project would occur when at it is determined that the project has been successful

or when the maximum ten-year monitoring period has been reached. Success would be

considered to have been achieved when the project objectives have been met, or when it is clear

that they will be met based upon the trends for the site conditions and processes. Project success

would be based on the following:

 Stabilization in the total area of marsh habitat

 Stabilization of elevations

 Stabilization of plant relative abundance

 Improvement in water quality

There may be issues related to the sustainability of the project that would require some

monitoring and management beyond achieving these objectives. Due to the variable nature of the

Louisiana coastal zone, the monitoring baseline may change during the period of analysis.

Consequently, it may be appropriate to consider extending project specific monitoring and

adaptive management beyond ten years.

8.0 COSTS FOR IMPLEMENTATION OF MONITORING AND

ADAPTIVE MANAGEMENT PROGRAMS

The costs associated with implementing these monitoring and adaptive management plans were

estimated based on currently available data and information developed during plan formulation

as part of the feasibility study. Because uncertainties remain as to the exact project features,

monitoring elements, and adaptive management opportunities, the costs estimated in Tables 1, 2,

and 3 (below) will be need to be refined in PED during the development of the detailed

monitoring and adaptive management plans. The current total estimate for implementing the

monitoring and adaptive management programs is approximately $21,189,500. Unless otherwise

noted, costs should begin at the onset of construction and should be budgeted as construction

costs.

8.1 Costs for Implementation of Monitoring Program

Costs to be incurred during the PED and construction phases include drafting of the detailed

monitoring plan, monitoring site establishment and pre-construction and construction data

acquisition to establish baseline conditions. Cost calculations for post-construction monitoring

are displayed as a ten-year (maximum) total. If ecological success is determined earlier (prior to

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ten years post-construction), the monitoring program will cease and costs will decrease

accordingly.

It is intended that monitoring conducted under the LCA program will utilize centralized data

management, data analysis, and reporting functions. It is proposed that all data collection

activities follow consistent and standardized processes regardless of the organization responsible

for monitoring. Costs were estimated for monitoring equipment, monitoring station

establishment, data collection, quality assurance/quality control, data analysis, assessment, and

reporting for the proposed monitoring elements and are summarized in Table 1 below. These

estimates account for a 2.6% annual inflation rate, adopted from the CWPPRA Program. The

current total estimate for implementing the monitoring program is approximately $19,209,500.

Unless otherwise noted, costs will begin at the onset of the PED phase and will be budgeted as

construction costs.

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Table 1. Preliminary Cost Estimates for Implementation of the Monitoring Program for

the LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes Project.

Category Activities 2 yr PED

Set-up &

Data

Acquisition

5 yr

Construction

10 yr Post

Construction

Total

Monitoring Monitoring workgroup,

Drafting detailed

monitoring plan,

Working with PDTs on

performance measures

:

planning and

management

$135,900 $91,015 $221,127 $448,042

Monitoring Landrights, site

construction, and

surveying

:

data collection $387,900

$387,900

Land:Water $40,500 $110,925 $269,498 $420,957

Habitat Classification $203,049 $493,320 $696,369

Channel Hydrology $501,400 $1,372,051 $3,333,488 $5,206,916

Marsh Hydrology $687,500 $1,881,280 $4,570,693 $7,139,433

Water Quality $54,900 $150,175 $364,859 $569,911

Vegetation $194,600 $532,438 $1,293,592 $2,020,594

Sediment accretion and

elevation

$77,800 $212,975 $517,437 $808,238

Fisheries $0* $0* $0* $0*

Database

Management

Database development,

management, and

maintenance, Webpage

development for

communication of data

to stakeholders

$145,500 $398,191 $967,430 $1,511,128

TOTAL $2,226,000 $4,952,099 $12,031,444 $19,209,488

*Costs have not been included for fisheries monitoring because it is assumed to be provided by existing

LDWF monitoring.

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8.2 Costs for Implementation of Adaptive Management Program

Costs for the project adaptive management program were based on level of effort. The current

total estimate for implementing the adaptive management program is $1,980,000. Unless

otherwise noted, costs will begin at the onset of the PED phase and will be budgeted as

construction costs.

Table 2. Preliminary Cost Estimates for Set-up of Adaptive Management Program for the

LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes Project.

Category Annual

Cost 7 yr Total

Detailed AM Plan and

Program Set-up

(During PED and Construction)

$100,000 $700,000

TOTAL $100,000 $700,000

Table 3. Preliminary Cost Estimates for Implementation of Adaptive Management

Program for the LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes

Project.

Category Annual

Cost 10 yr Total

Management of AM Program

(Post Construction) $50,000 $500,000

Assessment $47,000 $470,000

Decision Making $31,000 $310,000

TOTAL $128,000 $1,280,000

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9.0 LITERATURE CITED

Cretini, K.F., J.M. Visser, K.W. Krauss, and G.D. Steyer. 2010. CRMS Vegetation Analytical

Team Framework: Methods for Collection, Development, and Use of Vegetation Response

Variables. National Wetlands Research Center, Lafayette, LA, 64 p.

Folse, T.M., J.L. West, M.K. Hymel, J.P. Troutman, L. Sharp, D. Weifenbach, T. McGinnis, and

L.B. Rodrigue. 2008. A standard operating procedures manual for the Coast-wide Reference

Monitoring System-Wetlands: methods for site establishment, data collection, and quality

assurance/quality control: Baton Rouge, La., Louisiana Coastal Protection and Restoration

Authority, Office of Coastal Protection and Restoration, 191 p.

Mueller-Dombois, D. and H. Ellenberg 1974. Aims and Methods of Vegetation Ecology. New

York: John Wiley and Sons. 547 pp.

Standard Methods for the examination of water and wastewater. 18th edition, 1992. Greenberg,

A.E., R.R. Trussell, L.S. Clesceri, M.A.H. Franson, eds. American Public Health Association.

Washington D.C.

Steyer, G.D., and R.E. Stewart, Jr. 1992. Monitoring Program for Coastal Wetlands Planning,

Protection, and Restoration Act projects. U.S. Fish and Wildlife Service, National Wetlands

Research Center Open-File Report 93-01. 85 pp.

Steyer, G.D., R.C. Raynie, D.L. Steller, D. Fuller, and E. Swenson. 1995. Quality management

plan for Coastal Wetlands Planning, Protection, and Restoration Act monitoring program. OpenFile Report 95-01. Baton Rouge: Louisiana Department of Natural Resources, Coastal

Restoration Division. 97 pp.

Steyer, G.D., C.E. Sasser, J.M. Visser, E.M. Swenson, J.A. Nyman, and R.C. Raynie. 2003. A

Proposed Coast-wide Reference Monitoring System for Evaluating Wetland Restoration

Trajectories in Louisiana. Environmental Monitoring and Assessment. 81:107-117.

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ANNEX 1. LCA Convey Atchafalaya River Water to Northern Terrebonne

Marshes Project

Conceptual Ecological Model

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1.0 INTRODUCTION

1.1 CONCEPTUAL ECOLOGICAL MODEL DEFINITION

Although the term conceptual ecological model (CEM) may be applied to numerous disciplines, CEMs

are generally simple, qualitative models, represented by a diagram, that describe general functional

relationships among the essential components of an ecosystem. CEMs typically document and

summarize current understanding of, and assumptions about, ecosystem function. When applied

specifically to ecosystem restoration projects, CEMs also describe how restoration actions

propose to alter ecosystem processes or components to improve system health (Fischenich 2008).

To describe ecosystem function, a CEM usually diagrams relationships between major

anthropogenic and natural stressors, biological indicators, and target ecosystem conditions.

1.2 PURPOSE and FUNCTION of CONCEPTUAL ECOLOGICAL MODELS

CEMs can be particularly helpful with the Louisiana Coastal Area (LCA) Program and its

projects by providing assistance with four important tasks: ecosystem simplification,

communication, plan formulation, and science, monitoring and adaptive management.

1.2.1 Ecosystem Simplification

Because natural systems are inherently complex, resource managers must utilize tools that

simplify ecosystem relationships and functions within the target ecosystem. An understanding of

the target ecosystem is paramount to planning and constructing effective ecosystem restoration

projects. During CEM development, knowns and unknowns about the connections and

causalities in the systems are identified and delineated (Fischenich 2008).

CEMs can promote ecosystem simplification through the following processes:

 Organization of existing scientific information;

 Clear depiction of system components and interactions;

 Promotion of understanding of the ecosystem;

 Diagnosis of underlying ecosystem problems;

 Isolation of cause and effect relationships; and

 Identification of species most likely to demonstrate an ecosystem response.

1.2.2 Communication

CEMs are an effective tool for the communication of complex ecosystem processes to a large

diverse audience (Fischenich 2008). It is vitally important that project teams understand

ecosystem function in order to realistically predict accomplishments to be achieved by

restoration projects. CEMs can facilitate effective communication between project team

members about ecosystem function, processes, and problems, and can assist in reaching consensus

within the project team on project goals and objectives. Because CEMs summarize relationships

among the important attributes of complex ecosystems, they can serve as the basis for sound

scientific debate. Stakeholder groups, agency functions (e.g., planning and operations), and

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technical disciplines typically relate to systems resource use and management independently, but

CEMs can be used to link these perspectives.

The process of model development is at least as valuable as the model itself and affords an

opportunity to draw fresh insight as well as address unique concerns or characteristics for a given

project. Workshops to construct CEMs are brainstorming sessions that explore alternative ways

to compress a complex system into a small set of variables and functions. This interactive

process of system model construction facilitates communication between project team members

and almost always identifies inadequately understood or controversial model components.

CEMs can promote communication by facilitating the following:

 Integrating input from multiple sources and informing groups of the ideas, interactions,

and involvement of other groups. (Fischenich 2008);

 Assembling project/study managers with the project team and stakeholders to discuss ecosystem

condition, problems, and potential solutions;

 Synthesizing current understanding of ecosystem function;

 Developing consensus on a working set of hypotheses that explain habitat changes;

 Developing consensus on indicators that can reflect project specific ecological conditions; and

 Establishing a shared vocabulary among project participants.

1.2.3 Plan Formulation

Formulating a plan for an effective ecosystem restoration project requires an understanding of

the following elements:

1. The underlying cause(s) of habitat degradation;

2. The manner in which causal mechanisms influence ecosystem components and dynamics;

and

3. The manner in which intervening with a restoration project may reduce the effects of

degradation.

These three elements should form the basis of any CEM applied to project formulation

(Fischenich 2008).

CEMs can provide valuable assistance to the plan formulation process through the following:

 Supporting decision-making by assembling existing applicable science;

 Assisting with formulation of project goals and objectives, indicators, management

strategies, and results;

 Providing a common framework among team members from which to develop

alternatives;

 Supplementing numerical models to assess project benefits and impacts; and

 Identifying biological attributes or indicators that should be monitored to best interpret ecosystem

conditions, changes, and trends.

1.2.4 Science, Monitoring, and Adaptive Management

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Through the recognition of important physical, chemical, or biological processes in an

ecosystem, CEMs identify aspects of the ecosystem that should be measured. Hypotheses about

uncertain relationships or interactions between components may be tested and the model may be

revised through research and/or an adaptive management process. Indicators for this process may

occur at any level of organization, including the landscape, community, population, or genetic

levels; and may be compositional (i.e., referring to the variety of elements in a system), structural

(i.e., referring to the organization or pattern of the system), or functional (i.e., referring to

ecological processes) in nature.

CEMs can be helpful in restoration science, monitoring, and adaptive management through the

following:

 Making qualitative predictions of ecosystem response;

 Identifying possible system thresholds that can warn when ecological responses may

diverge from the desired effect;

 Outlining further restoration and/or research and development needs;

 Identifying appropriate monitoring indicators and metrics;

 Providing a basis for implementing adaptive management strategies;

 Interpreting and tracking changes in project targets;

 Summarizing the most important ecosystem descriptors, spatial and temporal scales, and

current and potential threats to the system;

 Facilitating open discussion and debate about the nature of the system and important

management issues;

 Determining indicators for monitoring;

 Helping interpret monitoring results and explore alternative courses of management;

 Establishing institutional memory of the ideas that inspired the management and

monitoring plan;

 Forecasting and evaluating effects on system integrity, stress, risks, and other changes;

 Identifying knowledge gaps and the prioritization of research;

 Interpreting and monitoring changes in target indicators; and

 Assisting in qualitative predictions and providing a key foundation for the development

of benefits metrics, monitoring plans, and performance measures.

1.2.5 Limitations of Conceptual Ecological Models

CEMs cannot identify the most significant natural resources within the target ecosystem or

prioritize project objectives. They do not directly contribute to the negotiations and trade-offs

common to ecosystem restoration projects. CEMs are not The Truth, but are simplified

depictions of reality. They are not Final, but rather provide a flexible framework that evolves as

understanding of the ecosystem increases. CEMs are not Comprehensive because they focus only

upon those components of an ecosystem deemed relevant while ignoring other important (but not

immediately germane) elements. CEMs do not, in and of themselves, quantify restoration

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outcomes, but identify indicators that can be monitored to determine responses within the target

ecosystem to restoration outputs.

Good conceptual models effectively communicate which aspects of the ecosystem are essential

to the problem, and distinguish those outside the control of the implementing agency. The best

conceptual models focus on key ecosystem attributes, are relevant, reliable, and practical for the

problem considered, and communicate the message to a wide audience.

1.3 TYPES of Conceptual Ecological Models

CEMs can be classified according to both their composition and their presentation format. They

can take the form of any combination of narratives, tables, matrices of factors, or box-and-arrow

diagrams. The most common types of CEMs are narrative, tabular, matrix, and various forms of

schematic representations. A comprehensive discussion of these types of CEMs is provided in

Fischenich (2008). Despite the variety in types of CEMs, no single form will be useful in all

circumstances (Fischenich 2008). Therefore, it is of vital importance to establish the specific

plan formulation needs to be addressed by the CEM, and develop the CEM accordingly because

[c]onceptual models . . . are most useful when they are adapted to solve specific problems

(Fischenich 2008).

1.3.1 Application of Conceptual Ecological Models to LCA Projects

CEMs have been widely used in other regions of North America when planning large-scale

restoration projects (Barnes and Mazzotti 2005). The LCA team has decided to utilize the Ogden

model (Ogden and Davis 1999). The LCA team recognizes that CEM development, like plan

formulation, is likely to be an iterative process, and that CEMs developed for LCA projects

during early plan formulation may be dramatically changed before project construction.

1.3.2 Model Components

The CEM utilized for LCA projects follows the top-down hierarchy of information using the

components established by Ogden and Davis (1999). The schematic organization of the CEM is

depicted in Figure 1 and includes the following components:

Drivers- This component includes major external driving forces that have large-scale

influences on natural systems. Drivers may be natural (e.g., eustatic sea level rise) or

anthropogenic (e.g., hydrologic alteration) in nature.

Ecological Stressors- This component includes physical or chemical changes that occur

within natural systems, which are produced or affected by drivers and are directly

responsible for significant changes in biological components, patterns, and relationships

in natural systems.

Ecological Effects- This component includes biological, physical, or chemical responses

within the natural system that are produced or affected by stressors. CEMs propose

linkages between one or more ecological stressors and ecological effects and attributes to

explain changes that have occurred in ecosystems.

Attributes- This component (also known as indicators or end points) is a frugal subset of

all potential elements or components of natural systems representative of overall

ecological conditions. Attributes may include populations, species, communities, or

chemical processes. Performance measures and restoration objectives are established for

each attribute. Post-project status and trends among attributes are measured by a system1008
29

wide monitoring and assessment program as a means of determining success of a program

in reducing or eliminating adverse effects of stressors.

Performance measures- This component includes specific features of each attribute to be monitored

to determine the degree to which the attribute is responding to projects designed to correct adverse

effects of stressors (i.e., to determine success of the project).

Figure 1. Conceptual Ecological Model Schematic Diagram.

This CEM does not attempt to explain all possible relationships or include all possible factors

influencing the performance measure targets within natural systems in the study area. Rather, the

model attempts to simplify ecosystem function by containing only information deemed most

relevant to ecosystem monitoring goals.

2.0 CONCEPTUAL ECOLOGICAL MODEL DEVELOPMENT

2.1 METHODOLOGY

A CEM was developed for the Convey Atchafalaya River Water to Northern Terrebonne

Marshes (ARTM) Project by members of the interagency Project Delivery Team. The creation of

this CEM was an interactive and iterative process. Prior to model development, the project team

reviewed existing information on the ecosystem within the study area. A small team meeting was

then convened to identify and discuss causal hypotheses that best explain both natural and key

anthropogenically-driven alterations in the study area. A list of appropriate stressors and

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consequent ecological effects in the study area ecosystem was developed from these discussions.

Additionally, a series of attributes was identified that exhibited characteristics that ideally suited

them to serve as key indicators of project success through the measurement and analysis of

performance measures associated with these attributes. The project team used these hypotheses

and lists of components to develop an initial draft of the model and to prepare a supporting

narrative document to explain the organization of the model and science supporting the

hypotheses. Additional information about the components of this CEM is presented below.

2.2 PROJECT BACKGROUND

The ARTM project was identified as a near-term critical feature in the Louisiana Coastal Area,

(LCA), Louisiana - Ecosystem Restoration Study (2004 LCA Plan; USACE 2004). The 2004

LCA Plan was recommended to Congress by a Chief of Engineers report dated January 31, 2005,

which recommended a coordinated, feasible solution to the identified critical water resource

problems and opportunities in coastal Louisiana. This project was included in that plan along

with other near-term critical restoration features throughout coastal Louisiana. Including this

project, 10 additional projects were recommended for further studies, in anticipation that such

features would be subsequently recommended for future Congressional authorization. The 2004

LCA Plan was developed by the State of Louisiana and the United States Army Corps of

Engineers (USACE) in order to implement the restoration strategies outlined in the 1998 report

Coast 2050: Toward a Sustainable Coastal Louisiana.

The purpose of this study is to investigate the feasibility of increasing Atchafalaya River

influence to central and eastern Terrebonne marshes via the Gulf Intracoastal Waterway

(GIWW) by enlarging channel constrictions and increasing Atchafalaya flows into the GIWW.

This Feasibility Study is authorized by the 2004 LCA Plan and the 2007 Water Resources

Development Act (WRDA 2007), which requires the completion of a Feasibility Study and the

incorporation of the study findings into a signed Chief of Engineers Report, which must be

submitted to Congress by the Secretary of the Army by December 31, 2010.

Pursuant to the completion of this Feasibility Study, a CEM was developed to establish causal

hypotheses that best explain the major alterations in the natural systems within the study area, to

identify attributes of the natural system that are likely to exhibit a response to project features,

and to identify performance measures that can be monitored to determine the degree of project

success with respect to countering or correcting the natural system alterations.

2.2.1 Project Goals and Objectives

The goal of the ARTM project is to reduce the current trend of degradation of the Terrebonne

marshes, so as to contribute towards achieving and sustaining a coastal ecosystem that can

support and protect the environment, economy, and culture of southern Louisiana and thus the

Nation.

The objectives of the project include the following:

 Prevent, reduce, and/or reverse future wetland loss;

 Protect vital socioeconomic resources including cultures, community, infrastructure,

business and industry, and flood protection;

 Achieve and maintain characteristics of sustainable marsh hydrology;

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31

 Reduce salinity levels in the project area;

 Increase sediment and nutrient load to surrounding wetlands;

 Increase residence time of fresh water; and

 Sustain productive fish and wildlife habitat.

2.2.2 Project Description

The ARTM study area comprises approximately 1,100 square miles (~700,000 acres) in southern

Louisiana in the vicinity of the City of Houma and Terrebonne Parish. The study area is

contained within the larger LCA Ecosystem Restoration Study Area, which has been identified

as the Louisiana coastal area from Mississippi to Texas. The proposed project is located in the

Deltaic Plain within Subprovince 3, one of the four Subprovinces identified in the LCA Study

Area.

The study area is bound to the west by the Lower Atchafalaya River, to the east by the Bayou

Lafourche ridge, and to the north by the Bayou Black ridge from the Lower Atchafalaya River to

the City of Houma and by the GIWW from the City of Houma to the Bayou Lafourche ridge.

The southern boundary of the project was roughly based on the 2007 delineation between

brackish and saline marsh habitat as identified by Sasser et al. (2008).

3.0 CONCEPTUAL ECOLOGICAL MODEL DISCUSSION

The CEM developed for the ARTM project is presented in Figure 2. Model components are

identified and discussed in the following subsections.

3.1 DRIVERS

3.1.1 Anthropogenic Alterations  Altered Hydrology

The central and eastern marshes of the project area do not receive adequate amounts of fresh

water or sediments from the Atchafalaya River (via the GIWW) or from the Mississippi River

(via Bayou Lafourche). Anthropogenic controls regulating the volume of water entering the

Atchafalaya River and Bayou Lafourche from the Mississippi River, in addition to the distance

of the marshes from these potential sources of fresh water and sediments, limit the benefits to the

central and eastern marshes. Consequently, subsidence and sea level rise are outpacing accretion

in most central and eastern marshes, resulting in increased submergence of marsh vegetation and

eventual marsh loss. In addition, canals and associated spoil banks, constructed for navigation

and/or oil and gas development, can be found throughout the project area. The canals serve as

easy routes for fresh and saltwater movement, serving as conduits for beneficial freshwater to

escape the system and for harmful saltwater to enter the system. In addition, spoil banks

compartmentalize wetlands, restricting water and animal movement between areas.

3.1.2 Storms and Hurricanes

Coastal storms, particularly tropical cyclone events, exert a stochastic but severe influence on the

study area. Data obtained from the National Oceanic and Atmospheric Administration (NOAA)

Coastal Services Center indicate that the storm centers of at least 19 tropical cyclones with a

Saffir-Simpson Hurricane Scale of Category 2 or higher have passed within 50 miles of the study

area during the interval 1851-2008, and at least 31 such tropical cyclones have passed within 100

miles of the study area during the same interval. The most recent tropical cyclones to affect the

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study area were Hurricanes Katrina and Rita, which occurred in August 2005 and September

2005, respectively, and Hurricanes Gustav and Ike, which occurred in September 2008.

Principal impacts to the marshes in the study area as a result of tropical cyclone events are due to

storm surge and associated erosion and saltwater intrusion. Storm surge exerts widespread stress

upon vegetation through the introduction of storm surge waters that exhibit higher salinity

concentrations than are normally present in surface waters within the study area and by direct

erosion of marsh plants and soils. Hurricanes Rita and Ike resulted in measurable storm surges

within the study area. Water gage data from the Houma Navigation Canal indicate storm surges

from Hurricanes Rita and Ike of approximately 5.0 feet and 6.3 feet above average water levels,

respectively.

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Figure 2. Conceptual Ecological Model, LCA Convey Atchafalaya River Water to Northern Terrebonne Marshes Project.

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3.1.3 Relative Sea Level Rise

Relative sea level rise consists of eustatic sea level rise combined with subsidence.

Eustatic sea level rise is defined as the global increase in oceanic water levels primarily

due to changes in the volume of major ice caps and glaciers, and expansion or contraction

of seawater in response to temperature changes. Baseline (i.e. recent) eustatic sea level

rise in the project area is approximately 0.75 feet/century. Subsidence is the decrease in

land elevations, primarily due to consolidation of sediments, faulting, groundwater

depletion, and possibly oil and gas withdrawal. Subsidence in the project area is

approximately 2.35 feet/century. Relative sea level rise affects project area marshes by

gradually inundating marsh plants. Marsh soil surfaces must vertically accrete to keep

pace with the rate of relative sea level rise or marshes eventually convert to open water

due to the depth of submergence.

3.2 ECOLOGICAL STRESSORS

3.2.1 Decreased Freshwater, Sediment, Nutrients, and Residence Time

The altered hydrology of the project area results in less freshwater and associated

sediment and nutrients being delivered to marsh vegetation. Lack of freshwater facilitates

increased saltwater intrusion and its associated effects on marsh vegetation. Vertical

accumulation of wetland soils is achieved by accretion of mineral sediment inputs and/or

organic accumulation resulting from above and below-ground plant productivity

(DeLaune et al. 1983; DeLaune et al. 1990a). The survival and productivity of marshes is

reliant on these soil-building processes to offset submergence and sea level rise (DeLaune

et al. 1978; DeLaune et al. 1979; DeLaune et al. 1990b). As the natural hydrology of the

project area marshes has become short-circuited by canals, the residence time of the

limited freshwater inputs has also decreased. Shorter residence times result in less settling

of suspended sediments and less uptake of nutrients.

3.2.2 Increased Saltwater Intrusion

The altered hydrology of the project area facilitates increased saltwater intrusion and

increased tidal exchange by providing efficient conduits for loss of freshwater and

intrusion of saltwater. Wetland plant species have evolved different levels of tolerance to

salinity and respond to salinity with different mechanisms. Numerous studies have

demonstrated that elevated salinity can negatively affect all wetland species and can

contribute to large-scale vegetation dieback (Chabreck and Linscombe 1982; McKee and

Mendelssohn 1989). Storm surge can also be a mechanism for saltwater intrusion. This

form of saltwater intrusion can be particularly detrimental to areas that have been

hydraulically isolated, leading to extended durations of saltwater inundation.

3.2.3 Increased Erosion

Significant and immediate erosion of marsh vegetation and associated soils can occur as a

result of storm surge events. Losses may be more significant in areas that are already

under stress from other ecological stressors, but healthy marsh systems can be

significantly impacted as well.

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3.3 ECOLOGICAL EFFECTS

3.3.1 Increased Submergence

Wetland plants employ different physical and/or metabolic mechanisms that enable them

to tolerate and grow in flooded soils. However, in almost all cases plants are dependent

on the maintenance of soil surface elevations to sustain the flooding regime to which they

are adapted. Increases in flooding depth and duration stress plants by altering metabolic

function and negatively impacting productivity, survival, and regeneration. Relative sea

level rise in the project area combined with insufficient accretion results in marsh

systems with reduced productivity, survival, and regeneration due to submergence.

Organic matter accumulation is also reduced, further exacerbating the impacts of

submergence.

3.3.2 Decreased Wetland Health

Decreased freshwater, decreased nutrients, decreased residence time, increased saltwater

intrusion, and increased submergence all act to decrease the overall health of the project

area marshes. As marsh plants become stressed by inundation and saltwater intrusion,

their productivity, survival, and regeneration are all negatively impacted. Over time,

healthy marshes gradually decline to more interspersed marshes and eventually convert to

open water.

3.3.3 Increased Wetland Loss

Wetland loss in the project area can be the result of gradual decline of marsh vegetation

due to inundation and saltwater intrusion eventually leading to complete loss of marsh

vegetation or the result of storm surge events. As marsh vegetation is lost, underlying

soils are more susceptible to erosion and are typically lost as well, leading to deeper

water and precluding marsh regeneration. Significant accretion of sediments is then

required in order for marsh habitat to reestablish.

3.4 ATTRIBUTESAND PERFORMANCE MEASURES

3.4.1 Elevation and Accretion

Ground surface elevation has been identified as a key indicator of project success with

respect to increasing sediment and nutrient load within the study area. Comparison of

pre-project elevations with post-project elevations would serve to determine if sediment

input and soil accretion is occurring within the study area in response to project features.

A post-project decrease in the rate of elevation decline would implicitly indicate the

introduction of nutrients and sediment into the marshes as a result of the project. Two

performance measures have been identified for this attribute, including surface elevation

table (SET) measurements and feldspar marker horizon measurements.

 Surface Elevation Table (SET) measurements provide a constant reference plane

in space from which the distance to the sediment surface can be measured by

means of pins lowered to the sediment surface. Repeated measurements of

elevation can be made with high precision because the orientation of the table in

space remains fixed for each sampling. Elevation change measured by the SET is

influenced by both surface and subsurface processes occurring within the soil

profile.

1015
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 Feldspar marker horizon measurements involve the placement of a cohesive layer

of feldspar clay on the ground surface. Soil borings are extracted at the marker

horizon location periodically to measure the amount of soil deposition and/or

accretion that has occurred above the horizon since placement. Significant

quantities of soil atop marker horizons are indicative of soil building within the

area, which in turn indicates an increase in relative elevation.

A post-project stabilization of elevation as evidenced by SET measurements or

documented soil accretion atop a marker horizon within the study area would be an

indication of significant project success, while a post-project decrease in the rate of

decline in elevation would be an indication of moderate project success. Conversely, no

change in the rate of elevation decline post-project within the study area would indicate

that the project did not succeed in offsetting subsidence and, by extension, habitat

conversion and future land loss.

3.4.2 Land Cover

Land cover has been identified as a key indicator of project success with respect to

preventing, reducing, or reversing wetland loss in the study area. Comparison of preproject land cover characteristics with post-project land cover characteristics would serve

to determine if the rate of conversion of marsh habitat to open water within the study area

declines post-project.

 Spatial analysis has been identified as a performance measure for the

determination of the response of land cover to the proposed project. Spatial

analysis may involve comparative analysis of pre-project and post-project aerial

or satellite imagery and may utilize thematic mapper analysis to determine

relative changes in habitat composition within the study area.

A post-project stabilization in the total area of marsh habitat would be an indication of

significant project success, while a post-project reduction in the rate of marsh loss within

the study area would be an indication of moderate project success. Conversely, no change

in the rate of marsh loss within the study area would indicate that the project did not

succeed in preventing habitat conversion and, by extension, future habitat loss.

3.4.3 Plant Diversity and Distribution

Plant diversity and distribution has been identified as a key indicator of project success

with respect to preventing, reducing, or reversing wetland loss in the study area.

Comparison of pre-project vegetation monitoring data with post-project vegetation

monitoring data would serve to determine if plant communities within the study area

change in response to project features. Relative abundance has been identified as the

performance measure for this attribute.

 Relative abundance is a measure of the abundance or dominance of each species

present in a sample. Relative abundance can be used to document the degree of

impact in an area by measuring both species dominance and evenness. Relative

abundance can be used to assess marsh health by comparing plant density before

and after project implementation. The Braun-Blanquet method (Mueller-Dombois

and Ellenberg 1974) as described in Steyer et al. (1995) will be utilized to

measure relative abundance.

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A post-project stabilization of relative abundance within the study area would be an

indication of significant project success, while a post-project reduction in the rate of

decline of relative abundance would be an indication of moderate project success.

Conversely, no change in the rate of decline of relative abundance post-project would

indicate that the project did not succeed in increasing vegetation productivity.

3.4.4 Water Quality

Water quality has been identified as a key indicator of project success with respect to

reducing salinity levels and increasing sediment and nutrient loads within the study area.

Comparison of pre-project water quality with post-project water quality would serve to

determine if freshwater throughput is introducing sediments and nutrients and flushing

out saline waters within the study area in response to project features. Three performance

measures have been identified for this attribute, including total suspended solids (TSS),

nutrients, and salinity.

 Total suspended solids (TSS) is a measurement of the total volume of sediment

suspended in a given volume of water. Project features are designed to increase

the amount of freshwater, and consequently suspended sediments, delivered to

marshes in the study area.

 Nutrients are chemical compounds or minerals contained in surface waters that

are extracted by organisms for nourishment. Common nutrients in surface waters

include nitrates, phosphates, and ammonia. Project features are designed to

increase the amount of freshwater, and consequently nutrients, delivered to

marshes in the study area.

 Salinity is a measure of the concentration of dissolved salt in a given volume of

water. Surface waters within the study area often exhibit elevated salinity levels

with respect to their historic levels due to the altered hydrology of the area and

periodically due to storm surge. Project features are designed to increase the

amount of freshwater in the project area and consequently reduce salinity levels.

Post-project improvements in water quality within the study area, as evidenced by

analysis of these measures, would be an indication of significant project success, while a

post-project stabilization or decline in water quality within the study area would indicate

that the project did not succeed in increasing riverine influence on the study area.

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4.0 LITERATURE CITED

Barnes, T.K. and F.J. Mazzotti. 2005. Using Conceptual Models to Select Ecological

Indicators for Monitoring. Restoration and Management of Estuarine Ecosystems. In:

S.A. Bortone (ed.) Estuarine Indicators, CRC Press, Boca Raton, FL.

Chabreck, R.H. and G. Linscombe. 1982. Changes in vegetative types in Louisiana

coastal marshes over a ten-year period. Louisiana Academy of Sciences 45:98102.

DeLaune, R.D., W.H. Patrick, Jr. and R.J. Buresh. 1978. Sedimentation rates determined

by 137 Cs dating in a rapidly accreting salt marsh. Nature 275:12. pp. 532-533.S. R.

Pezeshki, J. H. Pardue, J. H. Whitcomb, and W. H. Patrick, Jr. 1990. Some

DeLaune, R.D., R.J. Buresh, and W.H. Patrick, Jr. 1979. Relationship of soil properties to

standing crop biomass of Spartina alterniflora in a Louisiana marsh. Estuarine Coastal

Marine Science 8: 477-487.

DeLaune, R.D., C. J. Smith, and W. H. Patrick. 1983. Relationship of marsh elevation,

redox potential, and sulfide to Spartina alterniflora productivity. Soil Sci. Soc. AM. J.

47:930-935.

DeLaune, R.D., S. R. Pezeshki, J. H. Pardue, J. H. Whitcomb, and W. H. Patrick, Jr.

1990a. Some influences of sediment addition to a deteriorating salt marsh in the

Mississippi River deltaic plain: A pilot study. Journal of Coastal Research 6:1:181-188.

DeLaune, R.D., W.H. Patrick, and N. Van Breemen. 1990b. Processes governing marsh

formation in a rapidly subsiding coastal environment. Catena 17:277-288. Cremlingen,

Germany.

Fischenich, J.C. 2008. The Application of Conceptual Models to Ecosystem Restoration.

Engineer Research and Development Center Publication TN-EMRRP-EBA-01. U.S.

Army Corps of Engineers, Vicksburg District, Vicksburg, MS.

McKee, K.L. and I.A. Mendelssohn. 1989. Response of a freshwater marsh plant

community to increased salinity and increased water level. Aquatic Botany 34:301-316.

Mueller-Dombois, D. and H. Ellenberg. 1974. Aims and Methods of Vegetation Ecology.

New York: John Wiley and Sons. 547 pp.

Ogden, J.C. and S.M. Davis. 1999. The Use of Conceptual Ecological Landscape Models as

Planning Tools for the South Florida Ecosystem Restoration Programs. South Florida Water

Management District, West Palm Beach, FL.

Sasser, C.E., J.M. Visser, E. Mouton, J. Linscombe, and S.B. Hartley. 2008. Vegetation

types in coastal Louisiana in 2007: U.S. Geological Survey Open-File Report 20081224,

1 sheet, scale 1:550,000.

Steyer, G. D., R. C. Raynie, D. L. Steller, D. Fuller, and E. Swenson. 1995. Quality

management plan for Coastal Wetlands Planning, Protection, and Restoration Act

monitoring program. Open-file Series No. 95-01. Louisiana Department of Natural

Resources, Coastal Restoration Division, Baton Rouge.

U.S. Army Corps of Engineers. 2004. Louisiana Coastal Area (LCA) Ecosystem

Restoration Study. Volume I: Main Report. New Orleans District, New Orleans, LA.

1018
APPENDIX J:

REAL ESTATE PLAN

1019

Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate



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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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Louisiana Coastal Area

Near-Term Ecosystem Restoration Plan

Convey Atchafalaya River Water

To Northern Terrebonne Marshes

And Multipurpose Operation of

Houma Navigation Lock

1. PURPOSE


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2. DESCRIPTION OF LANDS, EASEMENT, AND RIGHT-OF-WAY (LER)

a. Description of Lands, Easements and Rights-of-Way (LER) required for the

construction, operation and maintenance of the project


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57.= 45:1 72<1 23 /41 02?17/ 0277 65/17 .= /41 7/5/1 >195871 /41B 561 =286.741C >B /41

/9453505B5 .:16 	50/?5/16 .=/687.2= 299867 ?41= 36174?5/16 302?7 C1961571 .= :208<1!

5002?.=A 750/?5/16 362< /41 A803! ?4.94 .7 415:.16 /45= 36174?5/16! /2 <2:1 .=05=C 26

G8;7/615<H 	50/?5/16 95= /41= .=3.0/65/1 36174 A628=C?5/16 5=C 7863591 ?5/16 78;;0.17! 5=C

C5<5A1 36174?5/16 1927B7/1<7 F/61<1 750.=./B 945=A17 95= 7/6177 36174 5=C .=/16<1C.5/1

<567417 /2 /41 ;2.=/ ?4161 :1A1/5/.2= C.17 5=C /41 ?1/05=C7 92=:16/ .=/2 2;1= ?5/16


41 5/.2=50 927B7/1< 17/265/.2=  ;05= 326 /4.7 617/265/.2= ;62E19/ .7 0/16=5/.:1

 0/16=5/.:1  .7 5072 /41 192<<1=C1C 05= ! 5=C 92=7.7/7 23 #& 315/8617 /45/

?280C .=961571 1F.7/.=A /9453505B5 .:16 .=3081=91 /2 91=/650 5I1 28C6158F 5=C 157/16=

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65=C 5B28 
1661>2==1 <567417 :.5 /41  >B .=/62C89.=A 302? .=/2 /41 5I1 28C6158F

5=C 65=C 5B28 57.=7 
4.7 ?.00 >1 5992<;0.741C >B 9615/.=A 92==19/.=A 945==107 /2 /4171

>57.=7 5/1C 92=/620 7/689/8617 ?280C >1 .=7/5001C /2 617/6.9/ 945==10 96277719/.2=7 /2 ;61:1=/

.=961571C 750/?5/16 .=/687.2= C86.=A /41 05/1 78<<16 5=C 3500 ?41= /9453505B5 .:16 .=3081=91

.7 /B;.9500B 02? 	2<1 58F.0.56B 36174?5/16 C.7/6.>8/.2= 7/689/8617 7894 57 980:16/7 ?.00 >1

.=908C1C 
4.7 ;62E19/ 5072 .=908C17 .=96157.=A 36174?5/16 78;;0B /4628A4 1=056A.=A 92=7/6.9/.2=7

.= /41  61CA.=A 23 916/5.= 95=507 ?.00 5002? 386/416 36174?5/16 9.69805/.2=! 5=C /41

C61CA1C <5/16.50 ?.00 >1 ;0591C .= 5CE591=/ <567417 .= 5= 13326/ /2 C1961571 <5674 365A<1=/5/.2=


41 ;0591<1=/ 23 <5/16.50 .= 7/65/1A.9 0295/.2=7 /2 92=7/689/ 6.CA17! 9615/.=A 5 /16659.=A 13319/!

?.00 716:1 /2 702? 36174?5/16 <2:1<1=/ 5=C 410; ;61:1=/ 750/?5/16 .=/687.2=

b. Total LER required for each project purpose and feature


4161 561 98661=/0B #& ;62;271C ;62E19/ 315/8617 /45/ 92<;6.71 /41   /2/50 23

5;;62F.<5/10B !'# 59617 .7 61D8.61C 326 /4.7 ;62E19/ 
41 /2/50 59615A1 61D8.61C 326 ?5/16

92=/620 7/689/8617 .7 5;;62F.<5/10B '' 59617 ;;62F.<5/10B #& 59617 .7 =1917756B 326 50/165/.2=

23 95=507 /4628A4 ;0591<1=/ 26 61<2:50 23 ;08A7 5=C /41 ;0591<1=/ 23 A5;7 ;;62F.<5/10B

! && 59617 561 =1917756B 326 /41 .<;62:1<1=/ 23 945==107 /4628A4 C61CA.=A! /41 871 23

980:16/7! 5=C 742610.=1 ;62/19/.2= ;;62F.<5/10B &(&" 59617 561 61D8.61C /2 5992<<2C5/1

<5674 617/265/.2= 13326/7 
41 92=7/689/.2= 23 5 ?1.6 ?.00 61D8.61 5;;62F.<5/10B  59617

;;62F.<5/10B # 59617 .7 =1917756B 326 /41 .<;62:1<1=/ 23  01:117 = 5CC./.2=50 #' #

59617 .7 61D8.61C 326 /1<;2656B ?26I 5615 = 5CC./.2= /2 /41 17/5/17 59D8.61C /2 5992<<2C5/1

;62E19/ 315/8617! 5;;62F.<5/10B  59617 23 2B7/16 015717 561 5=/.9.;5/1C /2 >1 C.619/0B

.<;59/1C 5=C! /41613261! <87/ >1 59D8.61C

c. Estates to be acquired.


41 4.13J7 1;26/ /45/ ?57 5;;62:1C .= 5=856B ))# 326 /41 ))  927B7/1<

17/265/.2= 	/8CB! 92=/5.=1C 71:1650 17/5/17 >2/4 7/5=C56C 5=C =2=7/5=C56C /2 >1 871C 326 /41

 ;62E19/7 
41 .7/6.9/ 59I=2?01CA17 /45/ ./ .7 26;7 23 =A.=1167 ;20.9B /2 59D8.61 311

7.<;01 /./01 326 1927B7/1< 617/265/.2= ;62E19/7 .= 26C16 /2 61C891 /41 6.7I /45/ .=92<;5/.>01 8717

2= ;62E19/ 05=C ?.00 29986 53/16 ;62E19/ 92=7/689/.2= 5=C /2 1=7861 /45/ 2?=1674.; 6.A4/7 :17/1C

.= /41 ;62E19/ 561 90156 5=C 1=326915>01  )#))! ;;1=C.F ! <1=C<1=/ K! 

)>5 2?1:16! 61A805/.2=7 5072 .=C.95/1 /45/ 5 017716 .=/1617/! 7894 57! 5 7;19.3.9 /B;1 23

;16<5=1=/ 1571<1=/! <5B >1 5;;62;6.5/1 C1;1=C.=A 8;2= /41 2;165/.2=50 61D8.61<1=/7 23 /41

;62E19/ 5=C 2/416 9.698<7/5=917 6101:5=/ /2 ;62E19/ .<;01<1=/5/.2=! .=908C.=A 05=C2?=16

;613161=91  "##)! &> .698<7/5=917 ?4161.= /41 59D8.7./.2= 23 .=/1617/7 0177 /45=

311 <5B >1 5;;62;6.5/1 .7 ?4161 2=0B 71019/ 5=C 157.0B .C1=/.3.5>01 5=C =5662? 533.6<5/.:1 6.A4/7

561 61D8.61C 326 7899177380 .<;01<1=/5/.2= 23 /41 ;62E19/  )#))! ;;1=C.F !

<1=C<1=/ K ! )>>.

4161 ;62E19/ 315/8617 1F.7/! /41 ;62;271C ;16<5=1=/ 17/5/1 59D8.7./.2= .7 7833.9.1=/ /2

5992<;0.74 92=7/689/.2=! 2;165/.2= 5=C <5.=/1=5=91 23 /41 315/861 
41 ;62E19/ 457 7;19.3.9

315/8617 .= C13.=1C 56157! 5=C /41 =1917756B 6150 17/5/1 6.A4/7 561 =5662?! 533.6<5/.:1 6.A4/7 /45/

95= 157.0B >1 C13.=1C / .7 >10.1:1C /45/ 5 6150 17/5/1 .=/1617/ .7 =2/ =1917756B 28/7.C1 /41 ;62E19/

315/861 56157 >195871 /41 17/5/17 ;62;271C 4161.= ;62:.C1 7833.9.1=/ 6.A4/7 /2 /41 2:16=<1=/ /2

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92=7/689/ /41 ;62E19/ 5=C 5072 ;62/19/ /41 .=/1617/7 23 /41 2:16=<1=/ >B ;624.>./.=A 871 23 /41

7863591 326 <.=1650 1F;0265/.2= 26 92=7/689/.2= 23 .<;62:1<1=/7 = 5CC./.2=! >195871 /41

;62E19/ 5615 .7 9257/50 ?1/05=C7! /41 ;62E19/ 315/8617 561 386/416 ;62/19/1C /4628A4 /41 ;20.91

;2?167 23 /41 1C1650 2:16=<1=/ /4628A4 	19/.2= ) 23 /41 015= 5/16 9/ ?4.94 61D8.61 5

;16<./ 362< /41 26;7 23 =A.=1167 326 5=B 59/.:./B /45/ 9280C =1A5/.:10B .<;59/ 5 ?1/05=C

57/0B! C81 /2 /41 /2;2A65;4B 23 /41 ;62E19/ 5615! ./ .7 4.A40B 8=0.I10B /45/ /41 >1=13.//1C <567417

9280C >1 C1:102;1C 
4171 /4611 ;62/19/.2=7 92<>.=1C A615/0B 61C891 /41 6.7I /45/ .=92<;5/.>01

8717 2= ;62E19/ 05=C7 ?.00 29986 53/16 92=7/689/.2=

00 C298<1=/5/.2= 57729.5/1C ?./4 /41 5;;62:50 61D817/ /2 C1:.5/1 362< 311 7.<;01 /./01

59D8.7./.2= .7 .=908C1C 57 F4.>./ 

=B 59/.:./B /45/ <5B 45:1 5 C1/6.<1=/50 13319/ /2 /41 >1=13./7 5615 23 /41 ;62E19/ .7

61A805/1C 
41613261 /41 6.7I7 2:16 /.<1 ?280C >1 <.=.<50 57.C1 362< 8=92=/62005>01 326917 7894

57 =5/861 4866.95=17! 1/9 
41 /B;17 23 59/.:./.17 /45/ ?280C >1 92=7.C161C 6.7I7 2.0*A57 7863591

1F;0265/.2=! 1F95:5/.2= 5=C 3.00 59/.:./.17! 1/9 561 98661=/0B 61A805/1C >B /41 28.7.5=5

1;56/<1=/ 23 5/8650 17286917! 
33.91 23 257/50 5=5A1<1=/! 8=C16 
./01 ! 45;/16 & 23

/41 28.7.5=5 C<.=.7/65/.:1 2C1 	;19.3.9500B! 78>945;/16 ! 	19/.2= &! 61D8.617

;16<./7 326 C61CA.=A 26 3.00.=A! 86>5= C1:102;<1=/7! 1=16AB C1:102;<1=/ 59/.:./B 1F;0265/.2=

5=C /65=7<.77.2= 23 2.0*A57! <.=.=A 59/.:./.17 7863591 L 78>7863591! 7863591 ?5/16 92=/620!

742610.=1 <2C.3.95/.2=! 619615/.2=50 C1:102;<1=/7! .=C87/6.50 C1:102;<1=/! C65.=5A1 ;62E19/7 5=C

G5=B 2/416 59/.:./.17 26 ;62E19/7 /45/ ?280C 61D8.61 5 ;16<./ 26 2/416 326< 23 92=71=/ 26

58/426.@5/.2= 362< /41 	 6<B 26;7 23 =A.=1167! /41 =:.62=<1=/50 62/19/.2= A1=9B! 26

/41 28.7.5=5 1;56/<1=/ 23 5/8650 17286917H CC./.2=500B! 59/.:./.17 .= /41 <567417

?1/05=C7 561 61A805/1C >B 	19/.2= ) 23 /41 015= 5/16 9/ 8=C16 /41 ;86:.1? 23 /41

	 16/5.= 2/416 59/.:./.17 561 61A805/1C >B /41 	 .74 5=C .0C0.31 	16:.91! /41

5/.2=50 56.=1 .7416.17 	16:.91! /41 ! 5=C /41 28.7.5=5 1;56/<1=/ 23 =:.62=<1=/50

%850./B


4161 561 71:1= & 17/5/17 ;62;271C 326 871 326 /4.7 ;62E19/M 3286 7/5=C56C 5=C /4611 =2=

7/5=C56C 
41 6192<<1=C1C 17/5/17 /2 >1 59D8.61C 561 1F;05.=1C >102?

Temporary Work Area Easement (standard estate)

 /1<;2656B 1571<1=/ 5=C 6.A4/23?5B .=! 2=! 2:16 5=C 596277 /41 05=C C1796.>1C .= 	941C801


659/ 2NNM 326 5 ;16.2C =2/ /2 1F911C /?2  B1567! >1A.==.=A ?./4 /41 C5/1 23 ;277177.2=

23 /41 05=C .7 A65=/1C /2 /41 =./1C 	/5/17! 326 871 >B /41 =./1C 	/5/17! ./7 61;6171=/5/.:17!

5A1=/7! 5=C 92=/659/267 57 5 ?26I 5615! .=908C.=A /41 6.A4/ /2 >2662? 5=C*26 C1;27./ 3.00! 7;2.0

5=C ?57/1 <5/16.50 /41612= <2:1! 7/261 5=C 61<2:1 1D8.;<1=/ 5=C 78;;0.17! 5=C 1619/ 5=C

61<2:1 /1<;2656B 7/689/8617 2= /41 05=C 5=C /2 ;16326< 5=B 2/416 ?26I =1917756B 5=C .=9.C1=/

/2 /41 92=7/689/.2= 23 /41 2=:1B /9453505B5 62E19/! /2A1/416 ?./4 /41 6.A4/ /2 /6.<! 98/! 3100

5=C 61<2:1 /4161362< 500 /6117! 8=C16>6874! 2>7/689/.2=7! 5=C 5=B 2/416 :1A1/5/.2=! 7/689/8617! 26

2>7/59017 ?./4.= /41 0.<./7 23 /41 6.A4/23?5BM 61716:.=A! 42?1:16! /2 /41 05=C2?=167! /41.6 41.67

5=C 577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57 <5B >1 871C ?./428/ .=/16316.=A ?./4 26 5>6.CA.=A

/41 6.A4/7 5=C 1571<1=/ 4161>B 59D8.61CM 78>E19/! 42?1:16! /2 1F.7/.=A 1571<1=/7 326 ;8>0.9

625C7 5=C 4.A4?5B7! ;8>0.9 8/.0./.17! 65.0625C7 5=C ;.;10.=17

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Fee excluding minerals (with restriction on use of the surface) (standard estate)


41 311 7.<;01 /./01 /2 /41 05=C C1796.>1C .= 	941C801 
659/ 2NN! 78>E19/! 42?1:16! /2

1F.7/.=A 1571<1=/7 326 ;8>0.9 625C7 5=C 4.A4?5B7! ;8>0.9 8/.0./.17! 65.0625C7 5=C ;.;10.=17M

1F91;/.=A 5=C 1F908C.=A 362< /41 /5I.=A 500 2.0 5=C A57! .= 5=C 8=C16 75.C 05=C 5=C 500

5;;86/1=5=/ 6.A4/7 326 /41 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C 2.0 5=C A57!

>8/ ?./428/ /41 6.A4/ /2 1=/16 8;2= 26 2:16 /41 7863591 23 75.C 05=C 326 /41 ;86;271 23 C6.00.=A 5=C

1F/659/.=A /4161362< 75.C 2.0 5=C A57

Channel improvement easement (standard estate)

 ;16;1/850 5=C 577.A=5>01 6.A4/ 5=C 1571<1=/ /2 92=7/689/! 2;165/1! 5=C <5.=/5.= 945==10

.<;62:1<1=/ ?26I7 2=! 2:16 5=C 596277 /41 05=C C1796.>1C .= 	941C801 
659/ 2NN 326 /41

;86;2717 57 58/426.@1C >B /41 9/ 23 2=A6177 5;;62:1C NNNNNNNNNNNNNNN! .=908C.=A /41 6.A4/

/2 90156! 98/! 3100! 61<2:1 5=C C.7;271 23 5=B 5=C 500 /.<>16! /6117! 8=C16>6874! >8.0C.=A7!

.<;62:1<1=/7 5=C*26 2/416 2>7/689/.2=7 /4161362<M /2 1F95:5/1! C61CA1! 98/ 5?5B! 5=C 61<2:1

5=B 26 500 23 75.C 05=C 5=C /2 ;0591 /41612= C61CA1 26 7;2.0 <5/16.50M 5=C 326 7894 2/416 ;86;2717

57 <5B >1 61D8.61C .= 92==19/.2= ?./4 75.C ?26I 23 .<;62:1<1=/M 61716:.=A! 42?1:16! /2 /41

2?=167! /41.6 41.67 5=C 577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57 <5B >1 871C ?./428/ .=/16316.=A

?./4 26 5>6.CA.=A /41 6.A4/7 5=C 1571<1=/ 4161>B 59D8.61CM 78>E19/! 42?1:16 /2 1F.7/.=A

1571<1=/7 326 ;8>0.9 625C7 5=C 4.A4?5B7! ;8>0.9 8/.0./.17! 65.0625C7 5=C ;.;10.=17

Flood Protection Levee Easement (standard estate)

 ;16;1/850 5=C 577.A=5>01 6.A4/ 5=C 1571<1=/ .= /41 05=C C1796.>1C .= 	941C801 
659/ 2NN

/2 92=7/689/! <5.=/5.=! 61;5.6! 2;165/1! ;5/620 5=C 61;0591 5 3022C ;62/19/.2= 01:11! .=908C.=A 500

5;;86/1=5=917 /4161/2M 61716:.=A! 42?1:16! /2 /41 2?=167! /41.6 41.67 5=C 577.A=7! 500 7894 6.A4/7

5=C ;6.:.01A17 .= /41 05=C 57 <5B >1 871C ?./428/ .=/16316.=A ?./4 26 5>6.CA.=A /41 6.A4/7 5=C

1571<1=/ 4161>B 59D8.61CM 78>E19/! 42?1:16! /2 1F.7/.=A 1571<1=/7 326 ;8>0.9 625C7 5=C

4.A4?5B7! ;8>0.9 8/.0./.17! 65.0625C7 5=C ;.;10.=17

Canal alteration easement (non-standard estate)

 ;16;1/850 5=C 577.A=5>01 6.A4/ 5=C 1571<1=/ .= /41 05=C C1796.>1C .= 	941C801 
659/ 2NN

/2 C1;27./ <5/16.507 ?./4.= 5=C 5628=C /41 95=50! /2 ;0591 ;08A7 26 3800B 90271 /41 95=50! /2 98/

A5;7 .= /41 95=50! 26 <5I1 2/416 50/165/.2=7 /2 /41 95=50! .= 26C16 /2 617/261 /41 4BC6202AB 5=C *26

/2 7/5>.0.@1 /41 7;2.0 >5=I7 502=A /41 95=50M 5=C 326 7894 2/416 ;86;2717 57 <5B >1 61D8.61C .=

92==19/.2= ?./4 75.C ?26I 23 .<;62:1<1=/M 61716:.=A! 42?1:16! /2 /41 2?=167! /41.6 41.67 5=C

577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57 <5B >1 871C ?./428/ .=/16316.=A ?./4 26 5>6.CA.=A /41

6.A4/7 5=C 1571<1=/ 4161>B 59D8.61CM 5=C 1F;61770B 1F91;/.=A 5=C 1F908C.=A 500 2.0! A57 5=C

2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! .= 5=C 8=C16 75.C 05=C 5=C 500

5;;86/1=5=/ 6.A4/7 326 /41 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C 2.0! A57 5=C

2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! >8/ ?./428/ /41 6.A4/ /2 1=/16 8;2=

26 2:16 /41 7863591 23 75.C 05=C 326 /41 ;86;271 23 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C

61<2:50 /4161362< 23 75.C 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287

326<M ;62:.C1C 42?1:16! /45/ /41 6.A4/7! .=/1617/7 5=C ;6.:.01A17! 57729.5/1C ?./4 /41 26.A.=50

95=50 6.A4/23?5B! 4161.=5>2:1 1F91;/1C 5=C 61716:1C 561 4161>B 78>26C.=5/1C /2 /41 6.A4/ 23

/4.7 95=50 50/165/.2= 1571<1=/

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'

Wetland creation and restoration easement (non-standard estate)

 ;16;1/850 5=C 577.A=5>01 1571<1=/ 5=C 6.A4/23?5B .=! 2=! 2:16 5=C 596277 /41 05=C C1796.>1C

.= 	941C801  
659/ 2  /2 92=7/689/! 2;165/1! <5.=/5.=! ;5/620! 61;5.6! 61=286.74! 5=C 61;0591

?1/05=C7 5=C 57729.5/1C 9257/50 45>./5/7! .=908C.=A /41 6.A4/ /2 >2662? 5=C*26 C1;27./ 3.00M /2

5992<;0.74 5=B 50/165/.2=7 23 92=/2867 2= 75.C 05=CM /2 ;05=/ :1A1/5/.2= 2= 75.C 05=CM /2 1F95:5/1!

C61CA1! 98/ 5?5B! 5=C 61<2:1 5=B 26 500 23 75.C 05=C 5=C /2 ;0591 /41612= C61CA1 26 7;2.0

<5/16.50M /2 92=7/689/ C.I17 5=C /2 .=7/500! 50/16! 610295/1! 61;5.6 26 ;08A 98/7 .= /41 >5=I7 23 C.I17M

/2 92=7/689/! 2;165/1 5=C <5.=/5.= ;.;10.=17 326 /41 ;86;271 23 C61CA1 26 7;2.0 <5/16.50 /65=7;26/

5=C C1;27./.2=M /2 <2:1! 7/261 5=C 61<2:1 1D8.;<1=/ 5=C 78;;0.17M /2 ;08A! 3.00 26 50/16 ;.;10.=1

95=507 0295/1C ?./4.= /41 0.<./7 23 /41 1571<1=/M /2 /6.<! 98/! 3100 5=C 61<2:1 /4161362< 500 /6117!

8=C16>6874! 2>7/689/.2=7! 5=C 5=B 2/416 :1A1/5/.2=! 7/689/8617! 26 2>7/59017 ?./4.= /41 0.<./7 23

/41 1571<1=/ 1F91;/.=A /41 7/689/8617 =2? 1F.7/.=A 2= /41 05=C! C1796.>1C 57 NNNNNNNNN!

;62:.C1C /45/ =2 2/416 7/689/8617 74500 >1 92=7/689/1C 26 <5.=/5.=1C 2= /41 05=C 1F91;/ 57 <5B >1

5;;62:1C .= ?6./.=A >B /41 61;6171=/5/.:1 23 /41 =./1C 	/5/17 .= 9456A1 23 /41 ;62E19/! /45/ =2

1F95:5/.2= 74500 >1 92=C89/1C 5=C =2 05=C3.00 ;0591C 2= /41 05=C ?./428/ 7894 5;;62:50 57 /2 /41

0295/.2= 5=C <1/42C 23 1F95:5/.2= 5=C*26 ;0591<1=/ 23 05=C3.00! O/45/ =2 :14.9017 74500 >1

2;165/1C ?./4.= /41 0.<./7 23 /41 1571<1=/ ?./428/ 7894 5;;62:50! 1F91;/ 57 <5B >1 61D8.61C /2

2;165/1 5=C <5.=/5.= /41 1571<1=/!P 5=C /45/ =2 /6.<<.=A! 98//.=A! 3100.=A 26 61<2:50 23 /6117!

8=C16>6874! 5=C 5=B 2/416 :1A1/5/.2= 74500 >1 92=C89/1C ?./428/ 7894 5;;62:50M /41 5>2:1 17/5/1

.7 /5I1= 78>E19/ /2 1F.7/.=A 1571<1=/7 326 ;8>0.9 625C7 5=C 4.A4?5B7! ;8>0.9 8/.0./.17! 65.0625C7

5=C ;.;10.=17M 61716:.=A! 42?1:16! /2 /41 A65=/267! 4.7 416 ./7 /41.6 41.67! 7899177267 5=C

577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57 <5B >1 871C ?./428/ .=/16316.=A ?./4 26 5>6.CA.=A /41

6.A4/7 5=C 1571<1=/ 4161>B 59D8.61CM 5=C 1F;61770B 1F91;/.=A 5=C 1F908C.=A 500 2.0! A57 5=C

2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! .= 5=C 8=C16 75.C 05=C 5=C 500

5;;86/1=5=/ 6.A4/7 326 /41 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C 2.0! A57 5=C

2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! >8/ ?./428/ /41 6.A4/ /2 1=/16 8;2=

26 2:16 /41 7863591 23 75.C 05=C 326 /41 ;86;271 23 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C

61<2:50 /4161362< 23 75.C 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287

326<

Dike (and/or weir) easement (non-standard estate)


41 ;16;1/850 5=C 1F9087.:1 6.A4/ /2 92=7/689/! <5.=/5.=! 61;5.6! 2;165/1! ;5/620 5=C 61;0591 5 C.I1

5=C*26 ?1.6! 2=! 2:16 5=C 596277 /41 05=C C1796.>1C .= 	941C801 
659/ 2NN .=908C.=A 500

5;;86/1=5=917 /4161/2M ;62:.C1C /45/ =2 45>./5>01 7/689/8617 74500 >1 92=7/689/1C 26 <5.=/5.=1C

2= /41 05=CM 1F91;/.=A 5=C 1F908C.=A 362< /41 /5I.=A 500 <.=16507! .= 5=C 8=C16 75.C 05=C 5=C 500

5;;86/1=5=/ 6.A4/7 326 /41 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C <.=16507!

>8/ ?./428/ /41 6.A4/ /2 1=/16 8;2= 26 2:16 /41 7863591 23 75.C 05=C 326 /41 ;86;271 23 C6.00.=A 5=C

1F/659/.=A /4161362< 75.C <.=16507


5>01  >102? C1;.9/7 /41 17/5/17 ;62;271C /2 >1 59D8.61C /2 5992<<2C5/1 1594

;56/.98056 ;62E19/ 315/861

1027
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

(

Table 2.1. Estate Table


5>017 ! ! 5=C  >102? C1;.9/ /41 ;16<5=1=/ 59615A1 61D8.61C! /41 5CC./.2=50

/1<;2656B 59615A1 61D8.61C! =8<>16 23 /659/7 53319/1C! A1=1650 2?=1674.; ;6.:5/1 :7 ;8>0.9 5=C

17/.<5/1C :5081 326 1594 ;56/.98056 ;62E19/ 315/861 326 /41 ?17/16=! 91=/650 5=C 157/16= 61A.2=7 23

/41 ;62E19/ 5615 617;19/.:10B 
41 17/.<5/1C :5081 .=908C17 17/.<5/1C 610295/.2= 927/7 326 /4271

;62;271C ;62E19/ 315/8617 ?4161 610295/.2=7 561 5=/.9.;5/1C


4161 561 98661=/0B 61CA1 .7;2750 56157 /45/ <5B >1 599177.>01 /2 72<1 23 /41 ;62;271C

;62E19/ 315/8617 2?1:16! >195871 23 /.<1 92=7/65.=/7 5=C 326 /41 ;86;2717 23 61572=5>01 927/

17/.<5/.2=! 5= 5CC./.2=50 )) 311/ 23 6.A4/23?5B ?.C/4 ?57 17/.<5/1C 326 C61CA.=A 315/8617 /2

5002? 326 C61CA1 C.7;2750 5CE591=/ /2 /41 C61CA1C 945==10 
45/ 5CC./.2=50 ?.C/4 .7 .=908C1C .=

500 C61CA1 315/8617! 5=C .7 92:161C >B /41 45==10 <;62:1<1=/ 571<1=/


5>01  17/16= 1A.2=  CC./.2=50 .A4/235B 11C1C

62E19/

15/861

16<5=1=/

9615A1

1D8.61C


1<;2656B

9615A1

1D8.61C

K 23 
659/7 
?=1674.; 7/.<5/1C 5081

  '# (  56.74 7717726 61926C7 .=C.95/1

;62;16/B .7 6.:5/1 L L

L 2?1:16! 	/5/1 905.<7 5

Q&!)))

7/5/1 62E19/ 15/8617 
2/50 59615A1

61D8.61C

11 1F908C.=A <.=16507 ?./4

;624.>./.2= 2= 871 23 /41 7863591

! #! !  ! !  !

#! 	!

'' 59617

5=50 0/165/.2= 571<1=/  ! ! &! $! $! ! !



#& 59617

45==10 <;62:1<1=/ 571<1=/



! "! &! ! ! #! "!

&! ! ! #! "! &! '!

(! )! ! ! ! !

!  ! "! &! ! !

! && 59617

1/05=C 615/.2= 5=C 17/265/.2=

571<1=/ L

! ! ! !  ! 
!


! 
! 
"! 
&! 
'

&(&" 59617


1<;2656B 26I 615 571<1=/ 00 315/8617 61D8.6.=A ;16<5=1=/ 62?

?.00 5072 61D8.61 /1<;2656B 92=7/689/.2=




#' # 59617

.I1 5=C*26 ?1.6 571<1=/   59617

022C 62/19/.2= 1:11 571<1=/ !  # 59617

1028
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation

Lock  Appendix J  Real Estate

)

;26/.2= 23 /41 ?5/16 >2//2<7

;62;271C 326 C61CA.=A

     ;26/.2= 23 ;62E19/ 315/861 .7 ?./4.=

	/5/1 905.<1C ?5/16 >2//2< 
41

61<5.=C16 .7 ?./4.= 
 


59D8.61C 326 

Q)!)))

    62;271C 315/861 0.17 ?./4.= 	/5/1

905.<1C ?5/16 >2//2< CE591=/

05=C2?=16 .7 ;6.:5/1

Q!)))

  (  62;271C 315/861 0.17 ?./4.= 	/5/1

905.<1C ?5/16 >2//2< CE591=/

05=C2?=16 .7 ;6.:5/1

Q!)))


5>01  1=/650 1A.2=  CC./.2=50 .A4/235B 11C1C

62E19/

15/861

16<5=1=/

9615A1

1D8.61C


1<;2656B

9615A1

1D8.61C

K 23 
659/7 
?=1674.; 7/.<5/1C 5081

    6.:5/1 2?=1674.; L ;8>0.9 
 	/5/1

?B   5B28 
1661>2==1 .7 	/5/1

905.<1C ?5/16 >2//2<

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1661>2==1 .7 	/5/1

905.<1C ?5/16 >2//2<

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    2950 2:16=<1=/ 80:16/ ?280C >1

;0591C 8=C16 
 ;56.74 


	46.<;16J7 2? 25C

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#    6.:5/1 R 560 1>05=9 Q!)))

"    6.:5/1 R 65=I  J<.92! 6 Q!)))

&   2= ;62;16/B

0.=1

6.:5/1 R 2=65C .928! 6 =26/416=

/659/ 2?=16') " L .0C61C 1>05=9

728/416=<27/ /659/ 2?=16&&#'

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'    6.:5/1 R .0C61C 1>05=9 Q!)))

(    6.:5/1 R .0C61C 1>05=9 5635./ Q!)))

)   2= ;62;16/B

0.=1

6.:5/1 R .0C61C 1>05=9 5635./

   L 56E26.1 1>05=9   

Q!)))

   2= ;62;16/B

0.=1

6.:5/1  56E26.1 1>05=9    L

10:.=5 1>05=9 86=/426=1   (

Q!)))

    6.:5/1 R 10:.=5 1>05=9 86=/426=1 Q!)))

1029
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation

Lock  Appendix J  Real Estate



  #   

 R 980:16/ 7./85/1C 8=C16 	/5/1

.A4?5B #& 5I5 65=C 5.0028 25C

Q !)))

    6.:5/1 R +1>19!  Q!)))

#    6.:5/1 R 
41 :17/ 2.7.=! 	6

26;265/.2= 75<1 05=C2?=16 57 

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 &  # 6.:5/1  23 /41 # ;569107 561 2?=1C >B

B;6177 .C15?5B! =9!  ;56910 .7

>5//861 05=C7! 5=C /41 2/416  ;569107

45:1 5 /2/50 23 # 0.7/1C 2?=167

Q#!)))

    6.:5/1 Q(!)))

    6.:5/1 R 	50:5C26  5<.=./5! 	6 L

2>16/  28C6158F! 6 S 5CC./.2=50

2?=167

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 (  # 6.:5/1 L ;8>0.9 2?=1674.; L ;8>0.9


 	/5/1 ?B   L 
 ;2?16

;2017 5=C 7/611/7 61CA1 5615 /4628A4

5B28 
1661>2==1 .7 	/5/1 905.<1C

?5/16 >2//2< 2/4 /41 1/42C.7/

1701B 	94220 5=C 5 ;6.:5/1 91<1/16B

?280C >1 53319/1C >B /4.7 315/861

Q!#' !)))

" ""  ) 6.:5/1 R 5.0028 62:1! ! +1>19!

! L # 5CC./.2=50 .=C.:.C8507

Q "!)))

& &'   6.:5/1 R .0<16 45<>1605.= L 0.1

1001A6.= 9*2 166B 5=1 5//1672=

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=11C1C

=2 62?

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) 80/.;86;271 2;165/.2= 23 ;62;271C

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  &"  6.:5/1 Q"!)))

 ( " ( 6.:5/1 R 56910! .6943.10C! 8.C6B!

8/46.1! 8I1! +1>19! ! 16C.=!

2.7.=! 56027

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  )&  5=C /659/7 561 2?=1C ;6.:5/10B

7941/1 7/5/1 R ' 0.7/1C 2?=167M 5=C

;5941 26/4 <16.95! =9 
4161 561

	/5/1 05.<1C ?5/16 >2//2<7 ?./4.= /41

315/861 5615 57 ?100 57 05=C 905.<1C >B

>2/4 /41 	/5/1 5=C /41 5CE591=/ ;6.:5/1

05=C2?=16

Q &!)))

  & "#  1560B 500 23 /41 ;62;16/B 61D8.61C 326

/4.7 ;62E19/ 315/861 .7 905.<1C >B >2/4

/41 	/5/1 5=C /41 5CE591=/ 05=C2?=167

R ;5941 26/4 <16.95! =9 

;569107 5=C 6=17/ 
4.>2C158F 7/5/1

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Q!)))

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926;265/.2=7  8;2=/! 566B 286A

Q !)))

1030
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation

Lock  Appendix J  Real Estate



26; L L2=292 
4161 .7 5

7<500 719/.2= 23 	/5/1 905.<1C ?5/16

>2//2<7 ?./4.= /4.7 ;62;271C 315/861

5615 .= 5CC./.2= /2 5 :16B 7<500 ;56910 23

05=C 905.<1C >B >2/4 /41 	/5/1 5=C /41

5CE591=/ 05=C2?=16

    6.:5/1 R 5;1B62871 	15322C 56 L

62916B! =9 415:.0B 871C ?5/16?5B

Q'!)))

    6.:5/1  
41 :17/ 2.7.=! 	6

26;265/.2= 75<1 05=C2?=16 57 #

Q!)))

	  #  6.:5/1 05=C7 5=C ;8>0.9 
 	/5/1

?B #&

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<16 7941/1 7/5/1 ' 0.7/1C 2?=167!

1=6B .61//1 7/5/1  0.7/1C 2?=167!

1=/865! L  	/ 56/.= 2! 
  

;569107

Q !)))


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/2/50 23 ' 0.7/1C 2?=167 23 /41 ( /659/7

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/2/50 23 " 0.7/1C 2?=167 23 /41 

/659/7

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;62E19/

315/861 2=

75<1 ;56910

57 >2/4 
&

L 
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	/5/1 05.<1C ?5/16 >2//2<7 
3 /41

61<5.=.=A 315/861 5615! 5;;62F.<5/10B

4503 23 /41 05=C .7 905.<1C >B >2/4 /41

	/5/1 5=C /41 5CE591=/ ;6.:5/1

05=C2?=16 
41 61<5.=C16 23 /41

;62E19/ 315/861 .7 2= ;62;16/B ?./4.=

;6.:5/1 926;265/1 2?=1674.; ;5941

26/4 <16.95! =9

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& # " "  
41 <5E26./B 23 /41 ;62E19/ 315/861 0.17

2= ;62;16/B 905.<1C >B >2/4 /41 	/5/1

05.<1C 5=C /41 5CE591=/ ;6.:5/1

05=C2?=16 ;5941 26/4 <16.95!

=9  :16B 7<500 ;26/.2= 23 /41

315/861 0.17 ?./4.= 	/5/1 905.<1C ?5/16

>2//2<7

Q!)))


' ) "''  
4.7 ;62E19/ 315/861 0.17 2= ;62;16/B

905.<1C >B >2/4 /41 	/5/1 5=C /41

5CE591=/ ;6.:5/1 05=C2?=16 ;5941

26/4 <16.95! =9

Q '!)))

1031
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation

Lock  Appendix J  Real Estate




5>01   57/16= 1A.2=  CC./.2=50 .A4/235B 11C1C

62E19/

15/861

16<5=1=/

9615A1

1D8.61C


1<;2656B

9615A1

1D8.61C

K 23 
659/7 
?=1674.; 7/.<5/1C 5081

    6.:5/1 Q!)))

    2.=/1 8F 41=17  Q!)))

# #' '  6.:5/1 /659/ L 8>0.9 


315/861 /2 ;577 8=C16  	/5/1

?B  R 286A56271 ?B

Q!)))

"   2= ;62;16/B 0.=1 6.:5/1 /659/7 L 8>0.9 


315/861 /2 ;577 8=C16  	/5/1

?B  R 286A56271 ?B

Q !)))

&    6.:5/1 /659/ 5=C 315/861 /2 ;577

8=C16 ;6.:5/1 625C

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41 728/416= ;26/.2= 23 /4.7 315/861

.7 ?./4.= /41 2.=/1 8F 41=17

 
41 =26/416= ;26/.2= .7 .=

6.:5/1 2?=1674.;

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/41 61<5.=C16

23 /4.7 315/861 .7

?5/16 >571C

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/41 2.=/1 8F 41=17 ! 5=C

5 ;26/.2= .7 .= 6.:5/1 2?=1674.;

= 5CC./.2=! 2=0B 5 ;26/.2= 23 /4.7

?5/16?5B .7 	/5/1905.<1C ?5/16

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# #   6.:5/1 Q!&#!)))

" '( "   ;26/.2= 23 /4.7 315/861 .7 ?./4.=

/41 2.=/1 8F 41=17 ! 5=C

5 ;26/.2= .7 .= 6.:5/1 2?=1674.;

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/41 2.=/1 8F 41=17 ! 5=C

5 ;26/.2= .7 .= 6.:5/1 2?=1674.;

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 "&   2.=/1 8F 41=17  Q#!)))

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   2.=/1 8F 41=17  Q!)))

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& ( #   ;26/.2= 23 /4.7 315/861 .7 ?./4.=

/41 2.=/1 8F 41=17 ! 5=C

5 ;26/.2= .7 .= 6.:5/1 2?=1674.;

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$ =2

;16<5=1=/

62? =11C1C

  6.:5/1 R 2= /41 =26/416= >26C16 23

/41 2.=/1 8F 41=17 

Q!)))

1032
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation

Lock  Appendix J  Real Estate

 

$ =2

;16<5=1=/

62? =11C1C

  2.=/1 8F 41=17  Q!)))

3. LERRD OWNED BY THE NON-FEDERAL SPONSOR


41 =2=31C1650 7;2=726 326 /4.7 ;62E19/ .7 /41 257/50 62/19/.2= 5=C 17/265/.2=

8/426./B 23 28.7.5=5 ! /4628A4 /41 
33.91 23 257/50 62/19/.2= 5=C 17/265/.2= 
4161

561 	2?=1C ?5/16 >2//2<7 61D8.61C 326 /4.7 ;62E19/

= 5CC./.2=! 71:1650 ;62;271C ;62E19/ 315/8617 561 ?./4.= /41 2.=/1 8F 41=17 .0C0.31

5=5A1<1=/ 615  
41  92<;6.717 5;;62F.<5/10B #!))) 59617 5=C .7 2?=1C >B

/41 28.7.5=5 1;56/<1=/ 23 .0C0.31 5=C .7416.17 
4161 561 101:1=  ;62;271C ;62E19/

315/8617 /45/ 0.1 92<;01/10B 26 ;56/.500B ?./4.= /41 2.=/1 8F 41=17 .0C0.31 5=5A1<1=/

615 .= 53286941 56.74  61D8.61C 326 /4271  315/8617 92=7/./8/1 /41 056A17/ 5615 23

92=/.A8287 05=C7 2?=1C >B /41 	/5/1 23 28.7.5=5 ?./4.= /41 ;62E19/ 5615

= 5CC./.2=! /4161 561 3286/11=   ;62E19/ 315/8617 /45/ 561 ;62;271C ?./4.= 	/5/1905.<1C

?5/16 >2//2<7 5=C*26 ?4161 >2/4 /41 	/5/1 23 28.7.5=5 5=C ;6.:5/1 ;56/.17 905.< /41 05=C*?5/16

>2//2<7

0/428A4 
5>017 !  L  .= /41 ;61:.287 719/.2= C1/5.0 500  61D8.61C 326 /41

;62E19/! 
5>01  >102? ;62:.C17 .=326<5/.2= 1F9087.:1 /2 /4271 ;62;271C ;62E19/ 315/8617 ?4161

/41 	/5/1 23 28.7.5=5 2?=7 26 905.<7 500 26 5 ;26/.2= 23 /41 61D8.61C  
2 >1 90156! 
5>01

 .7 =2/  .= 5CC./.2= /2 /45/ C1796.>1C .= 
5>017 !  L  ! ./ .7  2?=1C*905.<1C >B

/41 =2=31C1650 7;2=726 26 5= 57729.5/1C 	/5/1 5A1=9B /45/ .7 61D8.61C 326 /4.7 ;62E19/


41 5>2:1613161=91C 05=C7 5=C ?5/16 >2//2<7 561 5:5.05>01 326 /41 ;62E19/ >8/ =2/

7833.9.1=/ /2 92:16 /41 1=/.61 6.A4/23?5B =1917756B! /41613261 5CC./.2=50 1571<1=/7 ?.00 >1

=1917756B / /4.7 /.<1! =2=1 23 /41 6.A4/23?5B .C1=/.3.1C 57 	2?=1C 05=C7*?5/16 >2//2<7

45:1 >11= ;61:.2870B ;62:.C1C 57 5= ./1< 23 922;165/.2= 326 5=2/416 1C1650 ;62E19/ 61C./ ?.00

>1 6191.:1C 326 /41 61D8.61C 


5>01  	/5/1
?=1C 

62E19/

15/861

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9615A1

1D8.61C


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?=1674.; 7/.<5/1C

5081

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L L L 2?1:16! /41 	/5/1 23

28.7.5=5 905.<7 5 ;26/.2= 23 /41 ?5/16 >2//2<7

;62;271C 326 C61CA.=A

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59D8.61C 326 

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1033
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

#

>2//2< CE591=/ 05=C2?=16 .7 ;6.:5/1

   6.:5/1 2?=1674.; L ;8>0.9 
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5B28 
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61CA1 5615 /4628A4 5B28 
1661>2==1 .7 	/5/1

905.<1C ?5/16 >2//2< 2/4 /41 1/42C.7/ 1701B

	94220 5=C 5 ;6.:5/1 91<1/16B ?280C >1 53319/1C

>B /4.7 315/861

Q!#' !)))

  )& 5=C /659/7 561 2?=1C ;6.:5/10B 7941/1 7/5/1 R

' 0.7/1C 2?=167M 5=C ;5941 26/4 <16.95!

=9 
4161 561 	/5/1 05.<1C ?5/16 >2//2<7

?./4.= /41 315/861 5615 57 ?100 57 05=C 905.<1C >B

>2/4 /41 	/5/1 5=C /41 5CE591=/ ;6.:5/1 05=C2?=16

Q &!)))

  & "# 1560B 500 23 /41 ;62;16/B 61D8.61C 326 /4.7 ;62E19/

315/861 .7 905.<1C >B >2/4 /41 	/5/1 5=C /41

5CE591=/ 05=C2?=167 R ;5941 26/4 <16.95!

=9  ;569107 5=C 6=17/ 
4.>2C158F 7/5/1 ##

0.7/1C 2?=167

Q!)))

 "  (  ;6.:5/1 .=C.:.C8507!  ;6.:5/1 926;265/.2=7 

8;2=/! 566B 286A 26; L L2=292


4161 .7 5 7<500 719/.2= 23 	/5/1 905.<1C ?5/16

>2//2<7 ?./4.= /4.7 ;62;271C 315/861 5615 .=

5CC./.2= /2 5 :16B 7<500 ;56910 23 05=C 905.<1C >B

>2/4 /41 	/5/1 5=C /41 5CE591=/ 05=C2?=16

Q !)))


" "'   ;26/.2= 23 /41 315/861 5615 0.17 ?./4.= 	/5/1

05.<1C ?5/16 >2//2<7 
3 /41 61<5.=.=A 315/861

5615! 5;;62F.<5/10B 4503 23 /41 05=C .7 905.<1C >B

>2/4 /41 	/5/1 5=C /41 5CE591=/ ;6.:5/1 05=C2?=16


41 61<5.=C16 23 /41 ;62E19/ 315/861 .7 2= ;62;16/B

?./4.= ;6.:5/1 926;265/1 2?=1674.; ;5941 26/4

<16.95! =9

Q'!)))


& # " " 
41 <5E26./B 23 /41 ;62E19/ 315/861 0.17 2= ;62;16/B

905.<1C >B >2/4 /41 	/5/1 05.<1C 5=C /41 5CE591=/

;6.:5/1 05=C2?=16 ;5941 26/4 <16.95! =9

 :16B 7<500 ;26/.2= 23 /41 315/861 0.17 ?./4.=

	/5/1 905.<1C ?5/16 >2//2<7

Q!)))


' ) "'' 
4.7 ;62E19/ 315/861 0.17 2= ;62;16/B 905.<1C >B

>2/4 /41 	/5/1 5=C /41 5CE591=/ ;6.:5/1 05=C2?=16

;5941 26/4 <16.95! =9

Q '!)))

   2.=/1 8F 41=17  Q !)))

 ("  
41 728/416= ;26/.2= 23 /4.7 315/861 .7 ?./4.= /41

2.=/1 8F 41=17  
41 =26/416= ;26/.2= .7

.= 6.:5/1 2?=1674.;

Q (!)))

 (    ;26/.2= 23 /4.7 315/861 .7 ?./4.= /41 2.=/1 8F

41=17 ! 5=C 5 ;26/.2= .7 .= 6.:5/1

2?=1674.; = 5CC./.2=! 2=0B 5 ;26/.2= 23 /4.7

?5/16?5B .7 	/5/1905.<1C ?5/16 >2//2<7

Q')!)))

1034
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

"

" '( "  ;26/.2= 23 /4.7 315/861 .7 ?./4.= /41 2.=/1 8F

41=17 ! 5=C 5 ;26/.2= .7 .= 6.:5/1

2?=1674.;

Q#!)))

& ( '  ;26/.2= 23 /4.7 315/861 .7 ?./4.= /41 2.=/1 8F

41=17 ! 5=C 5 ;26/.2= .7 .= 6.:5/1

2?=1674.;

Q(!)))

 "&   2.=/1 8F 41=17  Q#!)))

 ))( "& 2.=/1 8F 41=17  Q &!)))

   2.=/1 8F 41=17  Q!)))

   2.=/1 8F 41=17  Q!)))

& ( #  ;26/.2= 23 /4.7 315/861 .7 ?./4.= /41 2.=/1 8F

41=17 ! 5=C 5 ;26/.2= .7 .= 6.:5/1

2?=1674.;

Q!)))

$ =2

;16<5=1=/

62? =11C1C

 2.=/1 8F 41=17  Q!)))

4. NON-STANDARD ESTATES DISCUSSION


41 ;62;271C =2=7/5=C56C 17/5/17! 95=50 50/165/.2= 1571<1=/! ?1/05=C 9615/.2= 5=C

617/265/.2= 1571<1=/! 5=C C.I1 5=C*26 ?1.6 1571<1=/! 561 .=908C1C 4161.=! 9 5>2:1 7 5072

<1=/.2=1C .= ! /41 4.13J7 1;26/ /45/ ?57 5;;62:1C .= 5=856B ))# 326 /41 )) 

927B7/1< 17/265/.2= 	/8CB! 92=/5.=1C 71:1650 17/5/17 >2/4 7/5=C56C 5=C =2=7/5=C56C /2 >1

871C 326 /41  ;62E19/7 ;;62:50 23 /4171 =2=7/5=C56C 17/5/17 .7 61D817/1C 57 ;56/ 23

C298<1=/ 5;;62:50 00 C298<1=/5/.2= 57729.5/1C ?./4 /41 5;;62:50 61D817/ 23 /41 =2=7/5=C56C

17/5/17 .7 .=908C1C 57 F4.>./ 

5. EXISTING FEDERAL PROJECTS WITHIN THE LERRD REQUIRED FOR THE

PROJECT


4161 561 /?2  1F.7/.=A 31C1650 ;62E19/7 /45/ 0.1 ?./4.= /41  61D8.61C 326 /4.7

;62E19/M /41  5=C /41 28<5 5:.A5/.2= 5=50

803 =/169257/50 5/16 5B , 571<1=/7 ?161 59D8.61C .= /41 ()J7 5=C

( )J7 326 G92=7/689/.2=! 1=056A1<1=/! 6150.A=<1=/! 2;165/.2= 5=C <5.=/1=5=91H! .= 5CC./.2= /2

GC8<;.=A ;6.:.01A17H C61CA1 C.7;2750 326 5=C .= 92==19/.2= ?./4 /41  ;62E19/

28<5 5:.A5/.2= 5=50 ,  9456A1 23 /4.7 ;62E19/ .7 /2 1:5085/1 <80/.;86;271

2;165/.2= 23 /41 28<5 29I 326 1=:.62=<1=/50 >1=13./7 	.=91 /41 28<5 29I 92=7/689/.2= .7

58/426.@1C 8=C16 /41 26A5=@5 /2 /41 803 ;62E19/! ./ ?57 92=7.C161C 5 ;6171=/ 92=C./.2=! 1:1=

/428A4 /4161 .7 =2 29I ;4B7.9500B ;6171=/ 5/ /4.7 /.<1 
41613261! ./ .7 5778<1C /45/ 500 6150

17/5/1 .=/1617/7 /45/ <5B >1 53319/1C >B 2;165/.2= 23 /41 28<5 29I ?.00 >1 5CC61771C .= /41

150 7/5/1 05= 326 /41 26A5=@5 /2 /41 803 ;62E19/

1035
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

&

6. FEDERALLY OWNED LAND REQUIRED FOR THE PROJECT


4161 .7 =2 31C16500B 2?=1C 05=C ?./4.= /41 ;62E19/ 5615! 50/428A4! 57 C1/5.01C 5>2:1

/4161 .7 31C16500B <5=5A1C 6.A4/23?5B

7. NAVIGATION SERVITUDE

5:.A5/.2= 	16:./8C1 5002?7 59D8.7./.2= 23 74261 05=C7 1F/1=C.=A /2 /41 26C.=56B 4.A4

?5/16 <56I /416123 5=C <5B >1 1F169.71C 8=C16 7/5/8/26B 6.A4/7 5=C ;2?167 ?./428/ 2>0.A5/.2=

326 92<;1=75/.2= /2 /41 6.;56.5= 05=C2?=167 / .7 =2/ 5=/.9.;5/1C /45/ 5:.A5/.2= 	16:./8C1 ?.00

>1 1F169.71C 326 /4.7 ;62E19/

8. MAPS

 62E19/ 	./1 <5; 95= >1 328=C .= F4.>./ ! ;5A1  742?.=A /41 A12A65;4.9 0295/.2= 23

/41 ;62E19/ 5615 ?./4 500 ;62;271C ;62E19/ 315/8617 05>101C F4.>./ ! ;5A17  C.7;05B 315/8617

.= /41 ?17/16=! 91=/650! 5=C 157/16= 61A.2=7 617;19/.:10B 
41 5CC./.2=50 <5;7 .=908C1C .= F4.>./

 C1;.9/ 1594 8=.D810B 05>101C 5=C =8<>161C ;62E19/ 315/861

9. INDUCED FLOODING

/ .7 =2/ 5=/.9.;5/1C /45/ .=C891C 3022C.=A ?.00 6.71 /2 /41 01:10 23 5 /5I.=A 326 ?4.94 E87/

92<;1=75/.2= ?.00 >1 2?1C 
41 <5; .=908C1C .= F4.>./  C1;.9/7 ?4161 ?5/16 01:107 561

5=/.9.;5/1C /2 6.71 326 916/5.= ;16.2C7 23 /.<1 5==8500B


41 <5E26./B 23 /41 56157 5=/.9.;5/1C /2 1F;16.1=91 70.A4/ .=9615717 .= ?5/16 101:5/.2=7 561

<567405=C7 00 1F.7/.=A :.5>01 8717 23 /41 <567405=C7 561 =2/ 1F;19/1C /2 >1 C1/6.<1=/500B

53319/1C >B /41 ;16.2C.9 945=A1 .= ?5/16 101:5/.2= 00 C1:102;1C 56157 ?./4.= /41 ;62E19/ 5615

561 ;62/19/1C >B 01:117 5=C*26 6.CA17 
41613261! /41 70.A4/ 5=C ;16.2C.9 .=961571 .= ?5/16 01:107

.7 =2/ 5=/.9.;5/1C /2 .<;59/ 5=B C1:102;1C 56157


41 
 ;62E19/ 315/8617 ?.00 <2C.3B 1F.7/.=A 56/.3.9.50 302? 5=C C65.=5A1 ;5//16=7 .=

26C16 /2 >1//16 5;;62F.<5/1 /41 ;5//16=7 /45/ 871C /2 =5/86500B 29986 
41 
 ;62E19/ 315/8617

561 =2/ ;61C.9/1C /2 7.A=.3.95=/0B .=961571 /41 <5A=./8C1 26 361D81=9B 23 .=8=C5/.2= /45/ ?.00

6191.:1 .=961571C 36174?5/16 302?7 =B .=961571 .= ?5/16 01:107 ?./4.= /41 ;62E19/ 5615 .7

C.619/0B 6105/1C .= .=961571C ?5/16 7/5A17 .= /41 /9453505B5 .:16 
41613261! 302?5A1

1571<1=/7 561 =2/ =1917756B ?./4.= /41 ;62E19/ 5615

10. BASELINE COST ESTIMATE

 927/ 17/.<5/1 23 /41 6150 ;62;16/B .=/1617/7 61D8.61C 326 /4.7 ;62E19/ .7 .=908C1C 57

F4.>./  
41 150 62;16/B 27/7 326 /41 ;62E19/ ?161 C16.:1C 362< 5 6277 ;;65.750 /45/ ?57

;16326<1C .= 191<>16 ))( =326<5/.2= 871C .= /41 6277 ;;65.750 ?57 2>/5.=1C 362< /41 56.74

7717726J7 233.91! 92<;565>01 75017! 5=C .=/16:.1?7 ?./4 02950 5;;65.7167 5=C 05=C2?=167 
41 	5017

2<;56.72= ;;62594 ?57 871C .= /41 5;;65.750 /2 C16.:1 98661=/ 35.6 <56I1/ :5081

1036
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

'

11. RELOCATION ASSISTANCE BENEFITS

=B 61D8.61C 610295/.2=7 ?.00 >1 ;16326<1C .= 59926C5=91 ?./4 /41 ;62:.7.2=7 23 8>0.9

5? (" "! /41 =.326< 10295/.2= 9/! 57 5<1=C1C 
5>01 " ;62:.C17 5 A1=1650

C1796.;/.2= 23 /41 .<;62:1<1=/7 ?./4.= 1594 ;62;271C ;62E19/ 315/861 ?4.94 <5B >1 10.A.>01 326

610295/.2= 
41 1=90271C 927/ 17/.<5/1 .=908C17 17/.<5/1C 610295/.2= 927/7 326 /4271 ;62;271C

;62E19/ 315/8617 ?4161 610295/.2=7 561 5=/.9.;5/1C

/ /4.7 /.<1! =2 17/.<5/1 .7 .=908C1C 326 ;277.>01 >87.=177 610295/.2= 927/7 57729.5/1C ?./4

2B7/16 01571 59D8.7./.2= 57 C.798771C .= 719/.2= ) >102? / .7! 42?1:16! 5=/.9.;5/1C /45/

<.=.<50 <2:.=A 927/7 <5B >1 57729.5/1C ?./4 /41 <2:.=A 23 <56I167 ;1672=50 ;62;16/B /45/

C10.=15/1 /41 01571C 56157

12. MINERAL ACTIVITY/TIMBER HARVESTING IN PROJECT AREA


41 ;62E19/ 5615 457 78>7/5=/.50 <.=1650 59/.:./B =:17/.A5/.2=7 561 2=A2.=A 61A56C.=A

<.=1650 .=/1617/! 2.0 L A57 .=/1617/7 = //26=1BJ7 
;.=.2= 23 2<;1=75>.0./B ?.00 /41= >1

;16326<1C 61A56C.=A 5=/.9.;5/1C .<;59/1C <.=1650 .=/1617/7 / .7 =2/ 5=/.9.;5/1C /45/

<16945=/5>01 /.<>16 ?.00 >1 .<;59/1C 57 5 61780/ 23 /4.7 ;62E19/

13. NON-FEDERAL SPONSOR ASSESSMENT


41 =2=31C1650 7;2=726 326 /4.7 ;62E19/ .7 /41 257/50 62/19/.2= 5=C 17/265/.2=

8/426./B 23 28.7.5=5 ! /4628A4 /41 
33.91 23 257/50 62/19/.2= 5=C 17/265/.2= 7

/41 =2=31C1650 7;2=726!  <87/ ;62:.C1 500 6150 17/5/1 .=/1617/7 61D8.61C 326 /41 ;62E19/! .1!

500 05=C7! 1571<1=/7! 6.A4/723?5B! 610295/.2=7! 5=C 5=B 2/416 .=/1617/! .=908C.=A 78./5>01 >2662?

5=C C61CA1C 26 1F95:5/1C <5/16.50 C.7;2750 56157 7


41 2=1C1650 	;2=726 .7 5771771C /2 >1 3800B 95;5>01 /2 ;16326< 500 59D8.7./.2=

59/.:./.17 57729.5/1C ?./4 /4.7 ;62E19/ 
41 	;2=726 457 /41 95;5>.0./B /2 59D8.61 5=C 420C 6150

17/5/1 57 ?100 57 /41 5>.0./B /2 92=/659/ 326 6150 17/5/1 716:.917 /2 78;;01<1=/ ./7 7/533 .= 26C16 /2

<11/ ;62E19/ 7941C8017 2?1:16! ./ <87/ >1 6192A=.@1C 4161.= /45/  .7 /41 =2=31C1650

7;2=726 326 500 1? 
6015=7 .7/6.9/ 9257/50 617/265/.2= ;62E19/7 5=C 500 4866.95=1 6.7I 61C89/.2=

;62E19/7 
41613261! .3 500  ;62E19/7 5=C 71:1650 4866.95=1 6.7I 61C89/.2= ;62E19/7 561

58/426.@1C 326 92=7/689/.2= 8=C16 92=98661=/ 7941C8017! /4161 .7 5 ;277.>.0./B /45/  <5B =2/

>1 5>01 /2 5992<;0.74  59D8.7./.2= C81 /2 /41 <577.:1 5<28=/ 23 ?26I 61D8.61C 326 7894 5=

8=C16/5I.=A 3 /45/ ?161 /41 9571! ./ .7 ;277.>01 /45/  <5B 61D817/ /45/ /41 1C1650

2:16=<1=/ 5992<;0.74 59D8.7./.2= 23  2= /41.6 >14503


41 77177<1=/ 23 /41 2=1C1650 	;2=726J7 150 7/5/1 9D8.7./.2= 5;5>.0./.17 .7

5//5941C 57 F4.>./ 

14. ZONING IN LIEU OF ACQUISITION


4161 ?.00 >1 =2 @2=.=A 26C.=5=917 1=59/1C /2 359.0./5/1 59D8.7./.2= 23 05=C 326 /41

;62E19/

1037
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

(

15. SCHEDULE

 C1/5.01C 7941C801 ?.00 >1 C1:102;1C ?41= /41 3.=50 
 .7 C1/16<.=1C 26<500B! 5=

17/.<5/1 23 2=1 B156 .7 5002?1C /2 59D8.61 
 326 5 ;62E19/ 2?1:16! 05=C 6.A4/7 59D8.7./.2=

?./4.= /41 ;62E19/ 5615 ?.00 >1 /.<1 92=78<.=A >195871 /4161 561 <80/.;01 2?=167 326 7.=A01

;569107 / .7 5=/.9.;5/1C /45/ 59D8.7./.2= 23 90156 /./01 ?.00 >1 C.33.980/ .= <5=B 95717

5=C2?=167 ?./4.= /41 ;62E19/ 5615 5072 .=908C1 056A1 926;265/.2=7 5=C 05=C <5=5A1<1=/

92<;5=.17 7894 57 2=/.=1=/50 5=C L 86! ;5941 
.0! 5=C 2=292 4.00.;7 326<160B

28.7.5=5 5=C L F;0265/.2= L 195871 23 /41 <5A=./8C1 23 59D8.7./.2= ;62;271C 326

/4.7 ;62E19/! 5= 59D8.7./.2= 7941C801 23 5/ 0157/ /?2 B1567 .7 92=7.C161C =1917756B

16. FACILITY OR UTILITY RELOCATION

/ .7 5=/.9.;5/1C /45/ 72<1 359.0./B 5=C*26 8/.0./B 610295/.2=7 ?.00 >1 61D8.61C 

;610.<.=56B 2;.=.2= 23 92<;1=75>.0./B .7 >1.=A ;61;561C 57 23 /41 C5/1 23 /4.7 61;26/ 2?1:16!

5= 17/.<5/1 23 0.I10B 359.0./B 610295/.2= 927/7 .7 .=908C1C .= /41 927/ 17/.<5/.=A ;26/.2= 23 /41

3157.>.0./B 61;26/ 57 92=7/689/.2= 927/7 
5>01 " C1;.9/7 5=/.9.;5/1C 8/.0./B*359.0./B 610295/.2=7

.= 92==19/.2= ?./4 1594 ;56/.98056 ;62;271C ;62E19/ 315/861 10295/.2=7 561 2=0B 5=/.9.;5/1C 326

/4271 315/8617 .=908C1C .= 
5>01 " 2 8/.0./B*359.0./B 610295/.2=7 561 5=/.9.;5/1C 326 /4271

315/8617 =2/ 0.7/1C .= /41 /5>01


5>01 " /.0./B*59.0./B 10295/.2=7

Project

Feature

Permanent

Acreage

Required

Temporary

Acreage

Required

# of

Utilities/

Facilities

Utility/Facility owner Improvements w/in

proposed feature

ROW included in

the appraisal

Affected Utility/Facility

# #' '  .A4?5B  

 2000 ft of 2-lane highway rerouted. Old

road alignment will be abandoned.

"    .A4?5B  

 200 ft long x 50 ft wide of 2-lane

highway will need to be dug up and

replaced so culvert can be installed

under road

&    6.:5/1 599177 625C 30 ft long x 40 ft wide of 2-lane private

drive will need to be dug up and

replaced so culvert can be installed

under road

 ("   .A4?5B  

 2<1 See EC6 and EC7

# #   .A4?5B  

 19615/.2=50

7/689/861*95>.=

See EC5.

    01:5/1C 	/5/1 .A4?5B "#(



 L 28<5 9./B 7/611/

R .= 92=E8=9/.2= ?./4 315/861

 

See CD4

    01:5/1C 	/5/1 .A4?5B "#(



 L 28<5 9./B 7/611/

R .= 92=E8=9/.2= ?./4 315/861

 

See CD4

    	46.<;16J7 2? C 


;56.74 
 2:16415C ;2?16

0.=17 5/ 96277.=A 1=/6B /2

95=50

 75 feet long x 30 ft wide of existing

bridge removed and replaced with

CC3 structure.

 8 diameter water line (75 feet

long) that is attached to the bridge

will need to be relocated.

 Power lines not anticipated to be

1038
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation

Lock  Appendix J  Real Estate

)

affected.

    	46.<;16J7 2? C 


;56.74 


	 ;2?16 ;2017

 75 feet long x 30 ft wide of existing

2 lane road will be excavated and

replaced with CC4 structure.

 6 diameter underground water

line (100 feet long) will need to be

relocated.

 Power lines not anticipated to be

affected.

  #  	/5/1 .A4?5B #& 

 See CD6

 &  ) 	 ;2?16 0.=1  The dredge cut passes under an

overhead line. There may be

clearance issues.

   ) 2 C298<1=/1C 8/.0./.17 17.C1=91  No known utilities affected.

 (  5/ 0157/ 	 0.=1! 
 0.=1!

2<957/! 	/5/1 ?B7 "#( L

 

! 5=C 28<5 9./B

7/611/7

) 617.C1=/.50

7/689/8617

 Potentially 3 electric poles with

associated overhead electric line

affected.

 Potentially 6 houses with unknown

underground utilities affected.

" ""   	 ;2017! 65=C 5.0028

25C 
 
!  


?5/16 0.=17

2<1  100 feet long x 40 feet wide 2 lane

highway to be excavated and

replaced with structure CC13

 Potentially 1 overhead electric line

might need to be temporarily

removed if there is a clearance

issue.

 8 diameter buried water line (100

feet long) will need to be relocated.

 12 diameter buried water line

(100 feet long) will need to be

relocated.

& &'   	 L =/16AB ;2?16 0.=17

96277 ;62;271C C61CA1 5615

 Potentially 1 overhead electric line

might need to be temporarily.

removed if there is a clearance

issue.

 The dredge will need to pass under

the Entergy overhead line. There

might be a clearance issue.

 ( "  	 ;2?16 0.=1  The levee will potentially pass

under an overhead electric line.

The poles are NOT in the way.

There may be a clearance issue

under the overhead line.

 "  (  	 ;2017 =156 =*? 926=16

23 ;62;271C ;62E19/ 315/861

<5F.<8< 23  ;2017

.<;59/1C

 One (1) pole is very near the berm

footprint and might need to be

relocated.

 The berm potentially passes under

an overhead electric line.

Clearance under the line may be

an issue.

   ) =/16AB ;2017 =156>B 74280C

=2/ >1 .<;59/1C

No affected utilities can be seen.

	  #  	/5/1 .A4?5B #& 



 
 ?5/16 0.=17

 50 ft x 40 ft wide bridge to be

removed and replaced with CS1

structure

 150 ft long x 40 ft wide highway to

be excavated and replaced.

 6 diameter water line (150 feet

total: 120 feet is buried, 30 feet is

attached to bridge) will need to be

relocated.

 12 diameter water line (150 feet

total: 120 feet is buried, 30 feet is

attached to bridge) will need to be

relocated.

1039
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation

Lock  Appendix J  Real Estate




 " &" ) =/16AB ;2017 =156>B 74280C

=2/ >1 .<;59/1C

No impact.

17. HTRW AND OTHER ENVIRONMENTAL CONSIDERATIONS

=:17/.A5/.2= 326 92=/5<.=5=/7 ?./4.= /41 ;62E19/ >28=C56.17 ?57 92=C89/1C .=

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617;2=71 59/.2=7 ?.00 >1 61D8.61C

2?1:16! .3 ./ .7 C.792:161C /45/ 9015=8; 26 617;2=71 59/.2=7 561 =1917756B! .=

59926C5=91 ?./4 6/.901   23 /41 157.>.0./B 27/ 	456.=A A611<1=/ 	! 1F198/1C 2= "

2:1<>16 ))'! G
41 =2=31C1650 7;2=726 74500 >1 617;2=7.>01 326 /41 /2/50 927/ 23 C1:102;.=A 5

617;2=71 ;05= 326 5CC6177.=A 5=B 45@56C287 78>7/5=917 61A805/1C 8=C16 /41 2<;6141=7.:1

=:.62=<1=/50 17;2=71! 2<;1=75/.2= 5=C .5>.0./B 9/ 23 (')! 8>  2 ("#)! ( 	/5/

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92=7/689/.2=! 2;165/.2=! 5=C <5.=/1=5=91 23 /41 ;62E19/ 	894 927/7 74500 =2/ >1 .=908C1C .= /2/50

7/8CB 927/7H

18. LANDOWNER ATTITUDE


4161 .7 5 A615/ C150 23 05=C2?=16 78;;26/ 326 /4.7 ;62E19/ 2?1:16! /4161 .7 5072 5 A615/

C150 23 92=916= /45/ 5CC./.2=50 ?5/16 .=/62C891C .=/2 /41 7B7/1< ?.00 5C:16710B 53319/ 3025/.=A

<567417 .= /41 5615M ;56/.980560B /4271 05=C7*<567417 2?=1C >B :16B 056A1 05=C2?=167

62;271C ;62E19/ 315/861  .7 5072 =2/ 5=/.9.;5/1C /2 >1 6191.:1C 35:265>0B >195871 ./ .7

.= C2?=/2?= 28<5 5/ /41 92=3081=91 23 /41  5=C 5B28 
1661>2==1 5=C ?.00 95871

92=7.C165>01 C.768;/.2= C86.=A 92=7/689/.2= = 26C16 /2 92=7/689/ /41 ;62;271C ;62E19/ 315/8617

.= /45/ 5615! 71:1650 617.C1=917 502=A ?./4 /41 ;8>0.9 8/.0./.17 57729.5/1C ?./4 /4271 617.C1=917

?280C >1 .<;59/1C 502=A ?./4 /41 1/42C.7/ 1701B 	94220 5=C 5 ;6.:5/1 91<1/16B 92=/5.=.=A

A65:17 C5/.=A >59I /2 /41 05/1 '))J7

19. NOTIFICATION TO THE NFS REGARDING THE RISKS ASSOCIATED WITH

ACQUIRING LAND BEFORE EXECUTION OF THE PROJECT PARTNERSHIP

AGREEMENT (PPA)

7 ;62E19/ 6.A4/23?5B .7 <261 901560B C13.=1C! /41 =2=31C1650 7;2=726 ?.00 >1 .7781C 5

6.7I 01//16 1F;05.=.=A /41 6.7I 23 59D8.6.=A 05=C7 ;6.26 /2 /41 1F198/.2= 23 /41  5=C 5C:.71C /2

?5./ 2= 9226C.=5/.2= 23 /41 59D8.7./.2= ;05= 5=C =2/.91 /2 ;62911C ?./4 59D8.7./.2=

20. OTHER REAL ESTATE ISSUES RELEVANT TO THE PROJECT

	28/416= 
1661>2==1 56.74 /41 728/416= ;26/.2= 23 /41 ;62E19/ 5615 .7 5>8=C5=/ ?./4

2B7/167 8=C61C7 23 	/5/1 2B7/16 015717 1F.7/ ?./4.= /41 ;62E19/ >28=C56B = 59926C5=91 ?./4

	/5/1 7/5/8/1! 500 2B7/16 01571 59615A1 C1/16<.=1C /2 >1 C.619/0B .<;59/1C >B 5 ;62E19/ 315/861 74500

>1 59D8.61C 
41 5615 23 .<;59/ /2 2B7/16 015717 .7 A1=16500B 92=7.C161C /2 >1 /41 322/;6.=/ 23 /41

;62E19/ 315/861 ;087 5= 5;;62F.<5/10B #) 322/ >83316 2=7.C16.=A 	/5/1 7/5/8/1! ./ .7 5=/.9.;5/1C

/45/ 5/ 0157/ 5 ;26/.2= 23 1.A4/11= ' 2B7/16 015717 ?.00 =11C /2 >1 59D8.61C 
5>01 ) >102?

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

 

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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1049
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate



1050
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate



1051
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate



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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

 

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

 

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

 

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

 

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

 

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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1071
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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1072
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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1073
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix J  Real Estate

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EXHIBIT B: INUNDATION MAP

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PROJECT FEATURES FOR ALTERNATIVE TWO



 
 


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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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TOTAL REAL PROPERTY COST FOR

ALTERNATIVE TWO $8,110,000

PROJECT FEATURES FOR ALTERNATIVE THREE

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TOTAL REAL PROPERTY COST FOR

ALTERNATIVE THREE $8,232,000

PROJECT FEATURES FOR ALTERNATIVE FOUR

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

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TOTAL REAL PROPERTY COST FOR

ALTERNATIVE FOUR $8,329,000

PROJECT FEATURES FOR ALTERNATIVE FIVE

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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TOTAL REAL PROPERTY COST FOR

ALTERNATIVE FIVE $8,451,000

PROJECT FEATURES FOR ALTERNATIVE SIX

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1089
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix J  Real Estate

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

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8717 2= ;62E19/ 05=C ?.00 29986 53/16 ;62E19/ 92=7/689/.2=! 5=C /2 1=7861 /45/

2?=1674.; 6.A4/7 :17/1C .= /41 ;62E19/ 561 90156 5=C 1=326915>01  )#))!

;;1=C.F ! <1=C<1=/ K! )>5 2?1:16! 61A805/.2=7 5072 .=C.95/1 /45/ 5

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C1;1=C.=A 8;2= /41 2;165/.2=50 61D8.61<1=/7 23 /41 ;62E19/ 5=C 2/416 9.698<7/5=917

6101:5=/ /2 ;62E19/ .<;01<1=/5/.2=! .=908C.=A 05=C2?=16 ;613161=91  "##)!

&> .698<7/5=917 ?4161.= /41 59D8.7./.2= 23 .=/1617/7 0177 /45= 311 <5B >1

5;;62;6.5/1 .7 ?4161 2=0B 71019/ 5=C 157.0B .C1=/.3.5>01 5=C =5662? 533.6<5/.:1 6.A4/7

561 61D8.61C 326 7899177380 .<;01<1=/5/.2= 23 /41 ;62E19/  )#))! ;;1=C.F

! <1=C<1=/ K ! )>>.

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# / .7 /41 2;.=.2= 23 /41 2=1C1650 	;2=726! 
41 257/50 62/19/.2= 5=C 17/265/.2=

8/426./B  5=C /41 .7/6.9/ /45/ 92=7/689/.2= 23 /4.7 ;62E19/ 95= >1

5992<;0.741C /4628A4 /41 59D8.7./.2= 23 ;16;1/850 1571<1=/7 65/416 /45= 311 
41

;62E19/ 457 7;19.3.9 315/8617 .= C13.=1C 56157! 5=C /41 =1917756B 6150 17/5/1 6.A4/7 561

=5662?! 533.6<5/.:1 6.A4/7 /45/ 95= 157.0B >1 C13.=1C 
41 7/5=C56C 45==10

<;62:1<1=/ 571<1=/ ?280C 5002? /41 2:16=<1=/ 7833.9.1=/ 6.A4/7 /2 92=7/689/

/?1=/B7.F " 23 /41 3.3/B71:1= #& ;62E19/ 315/8617! .=908C.=A /4.6/11=  C61CA1

98/7 5=C /4.6/11=  980:16/7 /2 5.C .= 36174?5/16 C.7/6.>8/.2= 
41 7/5=C56C 022C

62/19/.2= 1:11 571<1=/ ?280C 5002? /41 2:16=<1=/ 7833.9.1=/ 6.A4/7 /2 92=7/689/

/?2  01:117 .= /41 5I1 28C6158F 5615 .7/6.9/ 
33.91 23 28=710 457 ;61;561C 5

=2=7/5=C56C 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/ /45/ ?280C 5002? /41

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45>./5/ 5=C ?280C ;62/19/ /41 1=:.62=<1=/ >B ;624.>./.=A 92=7/689/.2= 23 7/689/8617!

1F95:5/.2= 23 /41 ;62;16/B 26 ;0591<1=/ 23 3.00 ?./428/ 5;;62:50 >B /41 =./1C 	/5/17


41 17/5/1 5072 ;624.>./7 871 23 /41 7863591 /2 1F;0261 326 <.=16507 .7/6.9/ 
33.91 23

28=710 457 5072 ;61;561C 5 =2=7/5=C56C 5=50 0/165/.2= 571<1=/ ?4.94 ?280C

5002? /41 ;0591<1=/ 23 <5/16.50 5=C 98//.=A 23 A5;7 .= 1F.7/.=A 95=507! 7;19.3.9500B

;624.>./7 /41 871 23 /41 7863591 326 <.=1650 1F;0265/.2= .= 5CC./.2= /2 ;624.>./.=A 5=B

59/.:./B /45/ .=/1631617 ?./4 /41 6.A4/7 23 /41 1571<1=/ .7/6.9/ 
33.91 23 28=710 457

5072 ;61;561C 5 =2=7/5=C56C .I1 5=C*26 1.6 571<1=/ /45/ ?280C 5002? /41

2:16=<1=/ 7833.9.1=/ 6.A4/7 /2 92=7/689/ /41 2=1  C.I1 5=C*26 ?1.6 315/861

C17.A=1C /2 61/5.= 36174 ?5/16 617.C1=91 /.<1 5=C 61C891 750/?5/16 .=/687.2= 5=C

?280C ;62/19/ /41 1=:.62=<1=/ >B ;624.>./.=A 92=7/689/.2= 23 7/689/8617 5=C /41 871 23

/41 7863591 /2 1F;0261 326 <.=16507

" / .7 /41 2;.=.2= 23 /41 .7/6.9/ /45/ /41 17/5/17 ;62;271C 4161.= ;62:.C1 7833.9.1=/

6.A4/7 /2 /41 2:16=<1=/ /2 92=7/689/ /41 ;62E19/ 5=C 5072 ;62/19/ /41 .=/1617/7 23 /41

2:16=<1=/ >B ;624.>./.=A 871 23 /41 7863591 326 <.=1650 1F;0265/.2= 26 92=7/689/.2=

23 .<;62:1<1=/7 = 5CC./.2=! >195871 /41 ;62E19/ 5615 .7 9257/50 ?1/05=C7! /41 ;62E19/

315/8617 561 386/416 ;62/19/1C /4628A4 /41 ;20.91 ;2?167 23 /41 1C1650 2:16=<1=/

/4628A4 	19/.2= ) 23 /41 015= 5/16 9/ ?4.94 61D8.61 5 ;16<./ 362< /41 26;7 23

=A.=1167 326 5=B 59/.:./B /45/ 9280C =1A5/.:10B .<;59/ 5 ?1/05=C 57/0B! C81 /2 /41

/2;2A65;4B 23 /41 ;62E19/ 5615! ./ .7 4.A40B 8=0.I10B /45/ /41 >1=13.//1C <567417 9280C

>1 C1:102;1C 
4171 /4611 ;62/19/.2=7 92<>.=1C A615/0B 61C891 /41 6.7I /45/

.=92<;5/.>01 8717 2= ;62E19/ 05=C7 ?.00 29986 53/16 92=7/689/.2=

& 
41 .7/6.9/ ;62;2717 /41 59D8.7./.2= 23 1571<1=/7 65/416 /45= 311 92=7.C16.=A /45/ /4.7

;62E19/ .7 2=1 23 # 28.7.5=5 257/50 615  ;62E19/7 ?4.94 920019/.:10B

1=92<;577 /42875=C7 23 59617 
41 C19.7.2=7 61A56C.=A ?4.94 17/5/17 /2 59D8.61 326


 ?.00 .<;59/ /41 2/416   ;62E19/7 
41 =2=31C1650 7;2=726! 
41 !

.7 =2/ .= 35:26 23 2?=.=A 311 .=/1617/ 2:16 /41 ;62E19/ 5615 326 
 
41 <.77.2= 23

/41 =2=31C1650 7;2=726 .7 /2 2:16711 500 4866.95=1 6.7I 61C89/.2= ;62E19/7 5=C 500

9257/50 617/265/.2= ;62E19/7 .= 728/4 28.7.5=5 
41 7;2=726 .7 ?.00.=A /2 59D8.61 5 311

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17/5/1 ?41= ./ .7 5>7208/10B =1917756B 326 /41 ;62E19/ 2?1:16! 2?=.=A 311 05=C7 326

;8>0.9 599177 .7 =2/ ?./4.= /41 58/426.@1C <.77.2=7 23 /41 =2=31C1650 7;2=726

' ;;62:50 23 /41 =2=7/5=C56C 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/ .7

61D817/1C >195871 /4161 .7 =2 7/5=C56C 1571<1=/ /45/ .=908C17 /41 6150 17/5/1 6.A4/7

=1917756B 326 92=7/689/.2= 23 916/5.= ;62E19/ 315/8617 
41 ;62E19/ .=908C17 C.7;2750

23 C61CA1C <5/16.50 .= C17.A=5/1C 56157 /2 871 ./ >1=13.9.500B /2 1=45=91 1F.7/.=A

<5674 5=C /2 ;62;5A5/1 /41 A62?/4 23 <5674 .= ?5/16>2//2<7

 
41 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/ ;62:.C17 500 /41 =1917756B 6.A4/7

/2 ;62/19/ /41 <5674 >1.=A 9615/1C 57 ?100 57 /41 <5674 /45/ ?.00 =5/86500B

;62;5A5/1 .= /41 ;62E19/ 5615 
41 2=0B ;2/1=/.50 8717 23 /41 ;62;16/B! A.:1= ./7

0295/.2= 5=C ;4B7.950 945659/16.7/.97! 561 326 619615/.2= 3.74.=A 5=C 48=/.=A!

2B7/16 456:17/.=A 5=C <.=1650 C1:102;<1=/ 19615/.2=50 8717 ?.00 =2/ .<;59/ /41

:.5>.0./B 23 /41 ;62E19/ 
41 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/

;624.>./7 /41 92=7/689/.2= 23 7/689/8617! 2;165/.2= 23 :14.9017! 1F95:5/.2= 23 /41

05=C! ;0591<1=/ 23 05=C3.00! 98//.=A 23 /6117! 5=C /41 871 23 /41 7863591 326 <.=1650

1F;0265/.2= ?./428/ ;6.26 5;;62:50 >B /41 =./1C 	/5/17

 
41 927/ 23 59D8.6.=A /41 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/ .7 0177 /45=

/41 927/ 23 59D8.6.=A 11 26 /41 ;86;2717 23 /4.7 ;62E19/ /41 1/05=C 615/.2=

5=C 17/265/.2= 571<1=/ .7 :5081C 5/ #)U 23 11 :5081

 
41 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/ ?57 ?6.//1= 87.=A 05=A85A1 362<

71:1650 7/5=C56C 17/5/17 7894 57 /41 16;1/850 1594 286.74<1=/ 571<1=/! /41

16;1/850 1594 	/26< 5<5A1 1C89/.2= 571<1=/ ! /41 11 F908C.=A

.=16507 ?./4 617/6.9/.2=7 2= 871 23 /41 7863591! 5=C /41 02?5A1 571<1=/

16<5=1=/ 022C.=A

 26 1571 23 61:.1?! 5//5941C 57 F4.>./  .7 5 4.A40.A4/1C :167.2= 23 /41 1/05=C

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7/5=C56C 17/5/17 5=C ?4.94 05=A85A1 .7 =2=7/5=C56C 072 5//5941C 57 F4.>./ 

.7 5 3.=50 :167.2= 23 /41 17/5/1 F4.>./  .7 5 ?6.//1= 7/5/1<1=/ 362< 
33.91 23

28=710 ! .=C.95/.=A /41 01A50 7833.9.1=9B 23 /41 2=	/5=C56C 7/5/1

( ;;62:50 .7 5072 61D817/1C 326 5 =2=7/5=C56C 5=50 0/165/.2= 571<1=/ >195871

/4161 .7 =2 7/5=C56C 1571<1=/ /45/ .=908C17 /41 6150 17/5/1 6.A4/7 =1917756B 326 /41

92=7/689/.2= 23 916/5.= ;62E19/ 315/8617 
41 ;62E19/ .=908C17 ;059.=A ;08A7 5=C

98//.=A A5;7 .= C17.A=5/1C 56157*95=507 /2 61C.619/ 36174?5/16 5=C 617/6.9/ 5 916/5.=

01:10 23 750/?5/16 362< 1=/16.=A 786628=C.=A <567405=C7

 
41 5=50 0/165/.2= 571<1=/ ;62:.C17 500 /41 =1917756B 6.A4/7 /2 92=7/689/!

2;165/1 5=C <5.=/5.= /41 ;08A7 5=C A5;7 57 ?100 57 5C5;/.:10B <5=5A1 /41 ?5/16

617/6.9/.2= 5=C 92=:1B5=91 57729.5/1C ?./4 /41 ;62E19/ 
41 ;2/1=/.50 8717 23 /41

;62;16/B A.:1= /41 0295/.2= 5=C ;4B7.950 945659/16.7/.97 561 326 >25/ /6533.9!

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<.=1650 C1:102;<1=/ 5=C 2B7/16 456:17/.=A 
41 5=50 0/165/.2= 571<1=/

7;19.3.9500B ;624.>./7 /41 871 23 /41 7863591 326 <.=1650 1F;0265/.2= .= 5CC./.2= /2

;624.>./.=A 5=B 59/.:./B /45/ .=/1631617 ?./4 /41 6.A4/7 23 /41 1571<1=/

 
41 927/ 23 59D8.6.=A /41 5=50 0/165/.2= 571<1=/ .7 0177 /45= /41 927/ 23

59D8.6.=A 11 F908C.=A .=16507 ?./4 617/6.9/.2=7 2= 871 23 /41 7863591 26

/41 ;86;2717 23 /4.7 ;62E19/ /41 5=50 0/165/.2= 571<1=/ .7 :5081C 5/ #)U 23 11

:5081

 26 1571 23 61:.1?! 5//5941C 57 F4.>./  .7 5 4.A40.A4/1C :167.2= 23 /41 5=50

0/165/.2= 571<1=/ ?4.94 .=C.95/17 ?4.94 05=A85A1 ?57 /5I1= 362< 7/5=C56C

17/5/17 5=C ?4.94 05=A85A1 .7 =2=7/5=C56C 072 5//5941C 57 F4.>./  .7 5 3.=50

:167.2= 23 /41 17/5/1 F4.>./  .7 5 ?6.//1= 7/5/1<1=/ 362< 
33.91 23 28=710

! .=C.95/.=A /41 01A50 7833.9.1=9B 23 /41 2=	/5=C56C 7/5/1

) ;;62:50 23 /41 =2=7/5=C56C .I1 5=C*26 1.6 571<1=/ .7 61D817/1C >195871

/4161 .7 =2 7/5=C56C 1571<1=/ /45/ .=908C17 /41 6150 17/5/1 6.A4/7 =1917756B 326 /41

92=7/689/.2= 23 916/5.= ;62E19/ 315/8617 
41 ;62E19/ .=908C17 ;059.=A 5 ?1.6 .= /41

C17.A=5/1C 0295/.2= /2 ;62<2/1 36174?5/16 61/1=/.2= 5=C .=4.>./ 750/?5/16 .=/687.2=

.=/2 /41 ;62E19/ 5615

 
41 .I1 5=C*26 1.6 571<1=/ ;62:.C17 500 /41 =1917756B 6.A4/7 /2 ;62/19/ 5615

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.=4.>./ 750/?5/16 .=/687.2= .=/2 /41 ;62E19/ 5615 
41 ;2/1=/.50 871 23 /41 ;62;16/B

A.:1= ./7 0295/.2= 5=C ;4B7.950 945659/16.7/.97 561 326 >25/ /6533.9 5=C 2B7/16

456:17/.=A 
41 .I1 5=C*26 1.6 571<1=/ ;624.>./7 /41 92=7/689/.2= 23

7/689/8617 5=C /41 871 23 /41 7863591 326 <.=1650 1F;0265/.2=

 
41 927/ 23 59D8.6.=A /41 .I1 5=C*26 1.6 571<1=/ .7 0177 /45= /41 927/ 23

59D8.6.=A 11 F908C.=A .=16507 ?./4 617/6.9/.2=7 2= 871 23 /41 7863591 26

/41 ;86;2717 23 /4.7 ;62E19/ /41 .I1 5=C*26 1.6 571<1=/ .7 :5081C 5/ #)U 23

11 :5081

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5=C*26 1.6 571<1=/ ?4.94 .=C.95/17 ?4.94 05=A85A1 ?57 /5I1= 362< 7/5=C56C

17/5/17 5=C ?4.94 05=A85A1 .7 =2=7/5=C56C 072 5//5941C 57 F4.>./  .7 5 3.=50

:167.2= 23 /41 17/5/1 F4.>./  .7 5 ?6.//1= 7/5/1<1=/ 362< 
33.91 23 28=710

! .=C.95/.=A /41 01A50 7833.9.1=9B 23 /41 2=	/5=C56C 7/5/1

 	.<.056 =2=7/5=C56C 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/! 5=50 0/165/.2=

571<1=/! 5=C .I1 5=C*26 1.6 571<1=/ ?161 ;61:.2870B .=908C1C .= /41

5;;62:1C ))  62E19/ 1;26/

1098
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>571C 2= /41 7/5=C56C 16;1/850 1594 286.74<1=/ 571<1=/ 5=C 2/416 7/5=C56C

17/5/17

 ;16;1/850 5=C 577.A=5>01 1571<1=/ 5=C 6.A4/23?5B .=! 2=! 2:16 5=C 596277 /41 05=C

C1796.>1C .= 	941C801  
659/ 2  /2 92=7/689/! 2;165/1! <5.=/5.=! ;5/620! 61;5.6!

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5=C /2 ;0591 /41612= C61CA1 26 7;2.0 <5/16.50M /2 92=7/689/ C.I17 5=C /2 .=7/500! 50/16!

610295/1! 61;5.6 26 ;08A 98/7 .= /41 >5=I7 23 C.I17M /2 92=7/689/! 2;165/1 5=C <5.=/5.=

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7/261 5=C 61<2:1 1D8.;<1=/ 5=C 78;;0.17M /2 /6.<! 98/! 3100 5=C 61<2:1 /4161362< 500

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/41 0.<./7 23 /41 1571<1=/ 1F91;/.=A /41 7/689/8617 =2? 1F.7/.=A 2= /41 05=C! C1796.>1C 57

NNNNNNNNNM ;62:.C1C /45/ =2 7/689/8617 326 ;16<5=1=/ 48<5= 45>./5/.2= 74500 >1

92=7/689/1C 26 <5.=/5.=1C 2= /41 05=CM /45/ =2 2/416 7/689/8617 74500 >1 92=7/689/1C 26

<5.=/5.=1C 2= /41 05=C 1F91;/ 57 <5B >1 5;;62:1C .= ?6./.=A >B /41 61;6171=/5/.:1 23 /41

=./1C 	/5/17 .= 9456A1 23 /41 ;62E19/! /45/ =2 1F95:5/.2= 74500 >1 92=C89/1C 5=C =2

05=C3.00 ;0591C 2= /41 05=C ?./428/ 7894 5;;62:50 57 /2 /41 0295/.2= 5=C <1/42C 23

1F95:5/.2= 5=C*26 ;0591<1=/ 23 05=C3.00! 5=C /45/ =2 /6.<<.=A! 98//.=A! 3100.=A 26 61<2:50

23 /6117! 8=C16>6874! 5=C 5=B 2/416 :1A1/5/.2= 74500 >1 92=C89/1C ?./428/ 7894 5;;62:50M

/41 5>2:1 17/5/1 .7 /5I1= 78>E19/ /2 1F.7/.=A 1571<1=/7 326 ;8>0.9 625C7 5=C 4.A4?5B7!

;8>0.9 8/.0./.17! 65.0625C7 5=C ;.;10.=17M 61716:.=A! 42?1:16! /2 /41 A65=/267! 4.7 416

./7 /41.6 41.67! 7899177267 5=C 577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57 <5B >1 871C

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1F;61770B 1F91;/.=A 5=C 1F908C.=A 500 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .=

0.D8.C 26 A571287 326<! .= 5=C 8=C16 75.C 05=C 5=C 500 5;;86/1=5=/ 6.A4/7 326 /41

1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C 2.0! A57 5=C 2/416 <.=16507

299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! >8/ ?./428/ /41 6.A4/ /2 1=/16 8;2= 26 2:16

/41 7863591 23 75.C 05=C 326 /41 ;86;271 23 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C

61<2:50 /4161362< 23 75.C 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26

A571287 326<

2/1 2=0B /41 05=A85A1 ?./4 61C 32=/ .7 =2=7/5=C56C 05=A85A1 00 2/416 05=A85A1 .7

/5I1= 362< 7/5=C56C 17/5/17

F4.>./ 

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 ;16;1/850 5=C 577.A=5>01 1571<1=/ 5=C 6.A4/23?5B .=! 2=! 2:16 5=C 596277 /41 05=C

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659/ 2  /2 92=7/689/! 2;165/1! <5.=/5.=! ;5/620! 61;5.6!

61=286.74! 5=C 61;0591 ?1/05=C7 5=C 57729.5/1C 9257/50 45>./5/7! .=908C.=A /41 6.A4/ /2

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5=C /2 ;0591 /41612= C61CA1 26 7;2.0 <5/16.50M /2 92=7/689/ C.I17 5=C /2 .=7/500! 50/16!

610295/1! 61;5.6 26 ;08A 98/7 .= /41 >5=I7 23 C.I17M /2 92=7/689/! 2;165/1 5=C <5.=/5.=

;.;10.=17 326 /41 ;86;271 23 C61CA1 26 7;2.0 <5/16.50 /65=7;26/ 5=C C1;27./.2=M /2 <2:1!

7/261 5=C 61<2:1 1D8.;<1=/ 5=C 78;;0.17M /2 ;08A! 3.00 26 50/16 ;.;10.=1 95=507 0295/1C

?./4.= /41 0.<./7 23 /41 1571<1=/M /2 /6.<! 98/! 3100 5=C 61<2:1 /4161362< 500 /6117!

8=C16>6874! 2>7/689/.2=7! 5=C 5=B 2/416 :1A1/5/.2=! 7/689/8617! 26 2>7/59017 ?./4.= /41

0.<./7 23 /41 1571<1=/ 1F91;/.=A /41 7/689/8617 =2? 1F.7/.=A 2= /41 05=C! C1796.>1C 57

NNNNNNNNN! ;62:.C1C /45/ =2 2/416 7/689/8617 74500 >1 92=7/689/1C 26 <5.=/5.=1C 2= /41

05=C 1F91;/ 57 <5B >1 5;;62:1C .= ?6./.=A >B /41 61;6171=/5/.:1 23 /41 =./1C 	/5/17 .=

9456A1 23 /41 ;62E19/! /45/ =2 1F95:5/.2= 74500 >1 92=C89/1C 5=C =2 05=C3.00 ;0591C 2= /41

05=C ?./428/ 7894 5;;62:50 57 /2 /41 0295/.2= 5=C <1/42C 23 1F95:5/.2= 5=C*26 ;0591<1=/

23 05=C3.00! O/45/ =2 :14.9017 74500 >1 2;165/1C ?./4.= /41 0.<./7 23 /41 1571<1=/ ?./428/

7894 5;;62:50! 1F91;/ 57 <5B >1 61D8.61C /2 2;165/1 5=C <5.=/5.= /41 1571<1=/!P 5=C /45/

=2 /6.<<.=A! 98//.=A! 3100.=A 26 61<2:50 23 /6117! 8=C16>6874! 5=C 5=B 2/416 :1A1/5/.2=

74500 >1 92=C89/1C ?./428/ 7894 5;;62:50M /41 5>2:1 17/5/1 .7 /5I1= 78>E19/ /2 1F.7/.=A

1571<1=/7 326 ;8>0.9 625C7 5=C 4.A4?5B7! ;8>0.9 8/.0./.17! 65.0625C7 5=C ;.;10.=17M

61716:.=A! 42?1:16! /2 /41 A65=/267! 4.7 416 ./7 /41.6 41.67! 7899177267 5=C

577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57 <5B >1 871C ?./428/ .=/16316.=A ?./4 26

5>6.CA.=A /41 6.A4/7 5=C 1571<1=/ 4161>B 59D8.61CM 5=C 1F;61770B 1F91;/.=A 5=C

1F908C.=A 500 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! .=

5=C 8=C16 75.C 05=C 5=C 500 5;;86/1=5=/ 6.A4/7 326 /41 1F;0265/.2=! C1:102;<1=/!

;62C89/.2= 5=C 61<2:50 23 75.C 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26

A571287 326<! >8/ ?./428/ /41 6.A4/ /2 1=/16 8;2= 26 2:16 /41 7863591 23 75.C 05=C 326 /41

;86;271 23 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 /4161362< 23 75.C 2.0! A57

5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26 A571287 326<

F4.>./ 

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4.7 .7 /2 916/.3B /45/ /41 1/05=C 615/.2= 5=C 17/265/.2= 571<1=/! 5 =2=

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5>2:1 613161=91C ;62E19/

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//26=1B 5<1! 
./01

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5/1

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 ;16;1/850 5=C 577.A=5>01 6.A4/ 5=C 1571<1=/ .= /41 05=C C1796.>1C .= 	941C801


659/ 2NN /2 C1;27./ <5/16.507 ?./4.= 5=C 5628=C /41 95=50! /2 ;0591 ;08A7 26 3800B

90271 /41 95=50! /2 98/ A5;7 .= /41 95=50! 26 <5I1 2/416 50/165/.2=7 /2 /41 95=50! .= 26C16 /2

617/261 /41 4BC6202AB 5=C *26 /2 7/5>.0.@1 /41 7;2.0 >5=I7 502=A /41 95=50M 5=C 326 7894

2/416 ;86;2717 57 <5B >1 61D8.61C .= 92==19/.2= ?./4 75.C ?26I 23 .<;62:1<1=/M

61716:.=A! 42?1:16! /2 /41 2?=167! /41.6 41.67 5=C 577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57

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59D8.61CM 5=C 1F;61770B 1F91;/.=A 5=C 1F908C.=A 500 2.0! A57 5=C 2/416 <.=16507 299866.=A

=5/86500B .= 0.D8.C 26 A571287 326<! .= 5=C 8=C16 75.C 05=C 5=C 500 5;;86/1=5=/ 6.A4/7 326

/41 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C 2.0! A57 5=C 2/416 <.=16507

299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! >8/ ?./428/ /41 6.A4/ /2 1=/16 8;2= 26 2:16

/41 7863591 23 75.C 05=C 326 /41 ;86;271 23 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C

61<2:50 /4161362< 23 75.C 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26

A571287 326<M ;62:.C1C 42?1:16! /45/ /41 6.A4/7! .=/1617/7 5=C ;6.:.01A17! 57729.5/1C ?./4

/41 26.A.=50 95=50 6.A4/23?5B! 4161.=5>2:1 1F91;/1C 5=C 61716:1C 561 4161>B

78>26C.=5/1C /2 /41 6.A4/ 23 /4.7 95=50 50/165/.2= 1571<1=/

F4.>./ 

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 ;16;1/850 5=C 577.A=5>01 6.A4/ 5=C 1571<1=/ .= /41 05=C C1796.>1C .= 	941C801


659/ 2NN /2 C1;27./ <5/16.507 ?./4.= 5=C 5628=C /41 95=50! /2 ;0591 ;08A7 26 3800B

90271 /41 95=50! /2 98/ A5;7 .= /41 95=50! 26 <5I1 2/416 50/165/.2=7 /2 /41 95=50! .= 26C16 /2

617/261 /41 4BC6202AB 5=C *26 /2 7/5>.0.@1 /41 7;2.0 >5=I7 502=A /41 95=50M 5=C 326 7894

2/416 ;86;2717 57 <5B >1 61D8.61C .= 92==19/.2= ?./4 75.C ?26I 23 .<;62:1<1=/M

61716:.=A! 42?1:16! /2 /41 2?=167! /41.6 41.67 5=C 577.A=7! 500 7894 6.A4/7 5=C ;6.:.01A17 57

<5B >1 871C ?./428/ .=/16316.=A ?./4 26 5>6.CA.=A /41 6.A4/7 5=C 1571<1=/ 4161>B

59D8.61CM 5=C 1F;61770B 1F91;/.=A 5=C 1F908C.=A 500 2.0! A57 5=C 2/416 <.=16507 299866.=A

=5/86500B .= 0.D8.C 26 A571287 326<! .= 5=C 8=C16 75.C 05=C 5=C 500 5;;86/1=5=/ 6.A4/7 326

/41 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C 2.0! A57 5=C 2/416 <.=16507

299866.=A =5/86500B .= 0.D8.C 26 A571287 326<! >8/ ?./428/ /41 6.A4/ /2 1=/16 8;2= 26 2:16

/41 7863591 23 75.C 05=C 326 /41 ;86;271 23 1F;0265/.2=! C1:102;<1=/! ;62C89/.2= 5=C

61<2:50 /4161362< 23 75.C 2.0! A57 5=C 2/416 <.=16507 299866.=A =5/86500B .= 0.D8.C 26

A571287 326<M ;62:.C1C 42?1:16! /45/ /41 6.A4/7! .=/1617/7 5=C ;6.:.01A17! 57729.5/1C ?./4

/41 26.A.=50 95=50 6.A4/23?5B! 4161.=5>2:1 1F91;/1C 5=C 61716:1C 561 4161>B

78>26C.=5/1C /2 /41 6.A4/ 23 /4.7 95=50 50/165/.2= 1571<1=/

F4.>./ 

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4.7 .7 /2 916/.3B /45/ /41 5=50 0/165/.2= 571<1=/! 5 =2=7/5=C56C 17/5/1! 457

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;62E19/

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//26=1B 5<1! 
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5/1

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

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 *
  	



41 ;16;1/850 5=C 1F9087.:1 6.A4/ /2 92=7/689/! <5.=/5.=! 61;5.6! 2;165/1! ;5/620 5=C

61;0591 5 C.I1 5=C*26 ?1.6 2=! 2:16 5=C 596277 /41 05=C C1796.>1C .= 	941C801 
659/

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92=7/689/1C 26 <5.=/5.=1C 2= /41 05=CM 1F91;/.=A 5=C 1F908C.=A 362< /41 /5I.=A 500

<.=16507! .= 5=C 8=C16 75.C 05=C 5=C 500 5;;86/1=5=/ 6.A4/7 326 /41 1F;0265/.2=!

C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C <.=16507! >8/ ?./428/ /41 6.A4/ /2 1=/16

8;2= 26 2:16 /41 7863591 23 75.C 05=C 326 /41 ;86;271 23 C6.00.=A 5=C 1F/659/.=A /4161362<

75.C <.=16507

F4.>./ 

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 *
  	



41 ;16;1/850 5=C 1F9087.:1 6.A4/ /2 92=7/689/! <5.=/5.=! 61;5.6! 2;165/1! ;5/620 5=C

61;0591 5 C.I1 5=C*26 ?1.6 2=! 2:16 5=C 596277 /41 05=C C1796.>1C .= 	941C801 
659/

2NN! .=908C.=A 500 5;;86/1=5=917 /4161/2M ;62:.C1C /45/ =2 45>./5>01 7/689/8617 74500 >1

92=7/689/1C 26 <5.=/5.=1C 2= /41 05=CM 1F91;/.=A 5=C 1F908C.=A 362< /41 /5I.=A 500

<.=16507! .= 5=C 8=C16 75.C 05=C 5=C 500 5;;86/1=5=/ 6.A4/7 326 /41 1F;0265/.2=!

C1:102;<1=/! ;62C89/.2= 5=C 61<2:50 23 75.C <.=16507! >8/ ?./428/ /41 6.A4/ /2 1=/16

8;2= 26 2:16 /41 7863591 23 75.C 05=C 326 /41 ;86;271 23 C6.00.=A 5=C 1F/659/.=A /4161362<

75.C <.=16507

F4.>./ 

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4.7 .7 /2 916/.3B /45/ /41 .I1 5=C*26 1.6 571<1=/! 5 =2=7/5=C56C 17/5/1! 457 >11=

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5/1

F4.>./ 

1108
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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Quality Control Checklist

Request to Deviated from Guidance as to Appropriate

Interest to Acquire

5=C*26

Request for Approval of Use of Non-standard Estate

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5 ;62E19/ 26 5 ;56/.98056 59D8.7./.2=

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F4.>./ 

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1110
K-1

APPENDIX K:

Economics Appendix

Benefit / Cost  Incremental Cost Analysis

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K-1

Volume III

APPENDIX K:

Economics

Cost Effectiveness & Incremental Cost Analysis

Appendix K1 Table of Contents

1.0 Purpose............................................................................................................................... 2

1.1 Alternative Plans............................................................................................................... 2

1.1.1 Description of Alternative Plans............................................................................... 2

1.1.2 Assessment Methods................................................................................................. 5

1.1.3 Cost Estimation......................................................................................................... 6

1.2 Cost Effectiveness (CE) .................................................................................................... 8

1.2.1 Alternatives Removed from Further Consideration.................................................. 8

1.2.2 Screening/Evaluation of Alternatives ....................................................................... 8

1.3 Incremental Cost Analysis (ICA) .................................................................................... 9

1.3.1 Incremental Cost Analysis Process........................................................................... 9

1.3.2 Results of the CE/ICA Process ............................................................................... 12

1.4 Other Factors .................................................................................................................. 14

1.4.1 Navigation Effects .................................................................................................. 14

1.4.2 Acceptability, Completeness, Effectiveness, and Efficiency.................................. 15

1.4.3 Recommendation of the Recommended Plan......................................................... 15

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K-2

1.0 PURPOSE

The purpose of this appendix is to describe the process by which alternatives for the LCA -

ARTM were developed and incrementally compared. A Cost Effectiveness & Incremental Cost

Analysis (CE/ICA) model (1) was utilized to evaluate and compare benefits and costs for each

Alternative.

1.1 ALTERNATIVE PLANS

1.1.1 Description of Alternative Plans

Conceptual alternatives were integrated with the suitable locations for diversion structures to

yield an array of alternatives that meet the goals and objectives of the project and are likely to

restore the impaired deltaic processes. The alternatives are:

Alternative 1 - No Action (Future without Project Condition)

This alternative includes no measures from this project. The future without project condition

will include sea level rise, subsidence, and other projects that are under construction or are likely

to be constructed.

Alternative 2 - Strategy: Utilize Existing Flow and Management Measures.

This alternative redistributes existing freshwater to benefit Terrebonne marshes using a variety of

measures. To achieve this, Gulf Intracoastal Waterway (GIWW) constrictions would be

eliminated. Additionally, the following measures to restrict increase, and control water are

proposed for each of the three subunits. In the West  Bayou Penchant Area, culverts, dredging,

bank protection, a sediment plug, and a weir will be utilized. In the Central  Lake Boudreaux

Area, culverts, levees, dredging, marsh terraces and berms, sediment plugs, modified operation

of the future HNC (Harbor Navigation Canal) lock complex, and a large sluice gated box culvert

are proposed. In the East  Grand Bayou Area, culverts, dredging, gaps in canal spoil banks,

marsh berms, sediment plugs, and removal of a weir and soil plug.

Alternative 3 - Strategy: Increase Atchafalaya River Flows and Management Measures.

This alternative will increase Atchafalaya River inflows and redistribute existing freshwater.

Thus, Alternative 3 includes all the measures in Alternative 2 and three additional. All three

measures are in the West  Bayou Penchant Area. To increase flows from the Atchafalaya River

to the GIWW, water will be moved from Bayou Shaffer to the Avoca Island Cutoff/Bayou

Chene. This will be accomplished by creating an opening through Avoca Island and installing a

large gated diversion structure (WS4) in the opening. The remaining two measures (WO1 and

WO2) would place stone along the shore of Bayou Chene and Avoca Island Cutoff to protect

from increased flows.

Alternative 4 - Strategy: Increase Flow from East of the Project Area and Management

Measures.

This alternative will increase freshwater flows from east of the project area and redistribute

existing freshwater. Thus, Alternative 4 includes all but one of the measures in Alternative 2,

(1) IWR-Planning Suite Model, version 2.0.1.0 Beta: Corps-certified.

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K-3

and has two additional measures. Alternative 4 varies from Alternative 2 by the measures in the

East  Grand Bayou Area. In Alternative 2, a bridge with Obermeyer gates (EC5) is proposed to

connect the GIWW to Grand Bayou under Hwy 24. In Alternative 4, this measure is replaced by

a pump station (ES2). This pump station would increase freshwater delivery to the Grand Bayou

watershed but not the other subunits. The second new measure is a soil plug (EP8) in Bayou

Leau Bleu. Bayou Leau Bleu connects the canal receiving the pump station outflow to the

GIWW. The pump station is pumping water from the GIWW, thus the soil plug is necessary to

prevent recirculation of water.

Alternative 5 - Strategy: Increase Flow from the East and from the Atchafalaya River and

Management Measures.

This alternative will increase flows from the east and west and redistribute existing freshwater.

This alternative is a combination of Alternatives 3 and 4. The only measure in Alternative 3 not

within this alternative is the Hwy. 24 Bridge with Obermeyer gates (EC5) which is replaced by a

pump station (ES2), as in Alternative 4.

Alternative 6 - Strategy: Increase Atchafalaya River Flow and Management Measures.

This alternative will increase Atchafalaya River inflows and improve the passage of freshwater

through the GIWW while slowing water passage to the gulf through the HNC. Alternative 6

differs from Alternative 3, because Alternative 6 only includes water management measures

along the GIWW. The measures to increase Atchafalaya River inflows are the same as

Alternative 3. A large gated diversion structure (WS4) would be placed in the new opening

created in Avoca Island. Shoreline protection would be placed (WO1 and WO2) in Bayou

Chene and Avoca Island Cutoff. To improve freshwater flows through the GIWW to Grand

Bayou, the following measures from Alternative 2 are proposed. In East  Grand Bayou Area,

dredging is proposed to connect Grand Bayou to the GIWW (ED5) and enlarge Grand Bayou

(ED3). In Central  Lake Boudreaux Area, the GIWW is constricted as it passed under Hwy. 24.

The Hwy. 24 bridge columns do not allow for channel enlargement. Therefore dredging a

secondary channel is proposed with two culverts; one under each Hwy. 24 bridge. Modifying

the operation of the HNC Lock Complex is also included in this alternative.

Alternative 7 - Strategy: Utilize Existing Flow and Management Measures.

This alternative will slow the movement of freshwater to the Gulf of Mexico and thus put

additional freshwater onto northern Terrebonne marshes. The one measure in this alternative is

modified operation of the proposed HNC Lock Complex (CL1). The HNC Lock Complex is part

of the proposed U.S. Army Corps of Engineers Morganza to the Gulf project for flood risk

management. The Lock Complex includes a set of navigable sector gates. Under normal

operation, the navigable sector gates would remain open with unrestricted vehicle passage and

closed during storm events and when the Atchafalaya River is low. This alternative proposes to

keep the sector gates closed more frequently to hold water back thus moving freshwater onto

northern marshes. When the sector gates are closed boat traffic would travel through the lock

chambers. As part of this alternative, an industry traffic management system would be

developed for vessels exceeding the lock size that will require the sector gates to be opened.

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Alternative 8 - Strategy: Utilize Existing Flow and Management Measures

This alternative redistributes existing freshwater to benefit eastern and central Terrebonne

marshes using a variety of measures. This alternative represents an increment between

Alternative 7 and Alternative 2 and contains many of the features of Alternative 2. In the Central

 Lake Boudreaux Area, culverts, levees, dredging, marsh terraces and berms, sediment plugs,

modified operation of the future HNC (Houma Navigation Canal) lock complex, and a large

sluice gated box culvert are proposed. In the East  Grand Bayou Area, culverts, dredging, gaps

in canal spoil banks, marsh berms, sediment plugs, and removal of a weir and soil plug are

proposed.

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1.1.2 Assessment Methods

Wetland Value Assessment

The Wetland Value Assessment (WVA) methodology is a quantitative habitat-based

assessment methodology developed for use in determining wetland benefits of project

proposals submitted for funding under the Coastal Wetlands Planning, Protection, and

Restoration Act (CWPPRA). The WVA quantifies changes in fish and wildlife habitat

quality and quantity that are expected to result from a proposed wetland restoration

project. The results of the WVA, measured in Average Annual Habitat Units (AAHUs),

can be combined with cost data to provide a measure of the effectiveness of a proposed

project in terms of annualized cost per AAHU gained. In addition, the WVA

methodology provides an estimate of the number of acres benefited or enhanced by the

project and the net acres of habitat protected/restored. Additional explanation of the

WVA methodology can be found in Section 3.5.2 of the Main Report.

Habitat variables considered appropriate for describing habitat quality in each wetland

type were selected according to the following criteria:

o The condition described by the variable had to be important in characterizing fish

and wildlife habitat quality in the wetland type under consideration;

o Values had to be easily estimated and predicted based on existing or readily

obtainable data (e.g., aerial photography, habitat classification data, water quality

monitoring stations, interviews with knowledgeable individuals, etc.); and

o The variable had to be sensitive to the types of changes expected to be brought

about by typical wetland restoration projects proposed under the Coastal Wetlands

Planning, Protection, and Restoration Act (CWPPRA).

Habitat Suitability Index

A habitat suitability index graph is a graphical representation of how fish and wildlife

habitat quality or "suitability" of a given habitat type is predicted to change as values of

the given variable change, and allows the model user to numerically describe, through a

Suitability Index, the habitat quality of a wetland area for any variable value. Each

Suitability Index ranges from 0.1 to 1.0, with 1.0 representing the optimal condition for

the variable in question. Suitability Index (SI) graphs are constructed for each variable.

The final step in model development was to construct a mathematical formula that

combines all Suitability Indices into a single Habitat Suitability Index (HSI) value.

Because the Suitability Indices range from 0.1 to 1.0, the HSI also ranges from 0.1 to 1.0,

and is a numerical representation of the overall or "composite" habitat quality of the

particular wetland area being evaluated. The HSI formula defines the aggregation of

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Suitability Indices in a manner unique to each wetland type depending on how the

formula is constructed.

Benefit Assessment

The net benefits of a proposed project are estimated by predicting future habitat

conditions under two scenarios: future without-project and future with-project.

Specifically, predictions are made as to how the model variables will change through

time under the two scenarios. Through that process, HSIs are established for baseline

(pre-project) conditions and for future without- and future with-project scenarios for

selected "target years" throughout the expected life of the project. Those HSIs are then

multiplied by the study area acreage at each target year to arrive at Habitat Units (HUs).

Habitat Units represent a numerical combination of quality (HSI) and quantity (acres)

existing at any given point in time. The HUs resulting from the future without- and

future with-project scenarios are annualized, averaged over the project life, to determine

Average Annual Habitat Units (AAHUs). The "benefit" of a project can be quantified by

comparing AAHUs between the future without- and future with-project scenarios. The

difference in AAHUs between the two scenarios represents the net benefit attributable to

the project in terms of habitat quantity and quality.

Based on the WVA process AAHUs were calculated for each of the alternatives. The Net

AAHUs generated for each Alternative are presented in Table K1.

Table K1: LCA-ARTM Benefits

Alternative Net AAHUs

Alt. 1 (No Action) N/A

Alt. 2 3,219.90

Alt. 3 3,325.45

Alt. 4 4,257.59

Alt. 5 4,718.61

Alt. 6 775.77

Alt. 7 243.20

Alt. 8 1,214.19

1.1.3 Cost Estimation

First Cost Construction

The CE/ICA process using IWR Suite is employed to further refine the preliminary

alternatives. The first step involves developing preliminary cost estimates for each

alternative. Items included in the first cost construction estimates include mobilization,

dredging, placement, demobilization, contingency, Engineering and Design during

Construction (EDC), Supervision & Administration (S&A), and Real Estate.

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OMRR&R Costs

Operation, maintenance, repair, rehabilitation and replacement (OMRR&R) costs are also

estimated for each alternative, compiling appropriate annual, 5-year and 10-year

OMRR&R costs for each alternative.

Monitoring Cost

Annual monitoring cost, estimated at $1,005,000, is included for Alternatives 2 through

8. For Alternatives 2, 3, 4, 5, 6, and 8, monitoring cost would be incurred annually for

the first decade of the project life cycle, starting in year 2013. However, for Alternative

7, monitoring cost would be incurred annually for the second decade of the project life

cycle, starting in year 2023.

All first costs, OMRR&R costs and monitoring costs are present-valued to the

beginning of the period of analysis (project life cycle), and amortized at the Fiscal Year

(FY) 2010 federal discount rate of 4.375 percent over the 50-year period of analysis, in

order to develop equivalent average annual (annualized) cost. Table K2 summarizes

these annualized costs associated with each alternative.

Table K2: LCA-ARTM: Step 1

Alternative Costs

Alternative First Cost*

Annualized

First Cost**

Annualized

Monitoring

Cost**

Annualized

OMRR&R**

Total

Annualized

Investment

Cost

Alt. 1 (No Action) N/A N/A N/A N/A N/A

Alt. 2 $203,047,200 $10,066,504 $396,686 $72,514 $10,535,704

Alt. 3 $232,041,000 $11,503,935 $396,686 $75,889 $11,976,509

Alt. 4 $253,038,800 $12,544,946 $396,686 $1,656,894 $14,598,526

Alt. 5 $294,899,600 $14,620,286 $396,686 $1,660,269 $16,677,241

Alt. 6 $134,199,000 $6,653,206 $396,686 $10,175 $7,060,066

Alt. 7 $42,000 $2,082 $258,513 $0 $260,595

Alt. 8 $86,777,600 $4,302,187 $396,686 $48,684 $4,747,557

*Includes Real Estate and

Cultural Resources

**Discount Rate: 4-3/8%

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1.2 COST EFFECTIVENESS (CE)

1.2.1 Alternatives Removed from Further Consideration

At this point in the analysis, Alternatives 4 and 5 (underlined above in Table K2) are

removed from consideration prior to performing the CE/ICA. At the TSP meeting, it was

determined Alternatives 4 and 5 were not sustainable from an efficiency or acceptability

standpoint. These alternatives required a large 4,000 cfs pumping station at the

confluence of the GIWW and Grand Bayou. The large pump station adversely impacted

the isohalines in the Barataria basin and would have forced salt water intrusion up into

Bayou Lafourche. The interagency team determined that these were unacceptable adverse

environmental impacts and precluded the alternatives from further consideration and

analysis. The effects of this pumping station do not conform to the USACE

Environmental Operating Principles concerning sustainability.

1.2.2 Screening/Evaluation of Alternatives

Prior to identifying cost effective alternatives, all five remaining alternatives

(Alternatives 2, 3, 6, 7, and 8) are sorted by Total AAHUs (average annual output level),

from lowest to highest. After sorting by Total AAHUs, any non-cost effective

alternatives are identified as either Inefficient in Production or Ineffective in Production.

These steps identify the least-cost alternative for every level of output under

consideration. Inefficient in Production is defined as any Alternative where the same

output level can be generated at a lesser cost by another alternative. The alternatives are

evaluated and wherever there are two or more Alternatives providing the same output

level, aside from any other considerations (i.e., uncertainty about the reliability of cost or

output estimates), the more costly alternative(s) generating that same output level is

eliminated as Inefficient in Production. Next, any alternatives that are Ineffective in

Production are identified. Ineffective in Production is defined as any alternative where a

greater output level can be generated at a lesser or equal cost by another alternative.

With the alternatives still sorted by output level (AAHUs), a pair-wise comparison of

output level and average annual cost is made for all remaining Alternatives that passed

the Inefficient in Production screening in the previous step. The alternatives are again

evaluated and any alternative generating less output at an equal or greater cost is

eliminated as Ineffective in Production. Noting Table K3, Alternative 6 generates less

output (AAHUs) than Alternative 8, (780.20 < 1,214.19). However, Alternative 6 has a

greater average annual cost than Alternative 8, ($5,792,824 > $4,747,577), and thus

Alternative 6, in italics, is identified and eliminated as being Ineffective in Production.

The four remaining alternatives that passed the Inefficient or Ineffective in Production

screenings, Alternatives 2, 3, 6, and 7, are all cost effective alternatives. Investment costs

and Net AAHUs for these remaining cost effective alternatives are presented in Table K4,

sorted by Net AAHUs.

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Table K3: LCA-ARTM: Step 2

Net

AAHUs

Average

Annual

Cost Per

Unit (AAHU)

Non-Cost Effective

Alternative Alternatives

Average

Annual

Cost

Alt. 1 (No Action) N/A 0 N/A

Alt. 7 $260,595 243.20 $1,071.53

Alt. 6 $5,792,824 775.77 $7,467.19 Ineffective in Production

Alt. 8 $4,747,577 1,214.19 $3,910.06

Alt. 2 $10,535,704 3,219.90 $3,272.06

Alt. 3 $11,976,509 3,325.45 $3,601.47

Table K4: LCA-ARTM: Step 2

Net

AAHUs

Average

Annual

Cost Per

Alternative Unit (AAHU)

Average

Annual

Cost

Alt. 1 (No Action) N/A 0 N/A

Alt. 7 $260,595 243.20 $1,071.53

Alt. 8 $4,747,577 1,214.19 $3,910.06

Alt. 2 $10,535,704 3,219.90 $3,272.06

Alt. 3 $11,976,509 3,325.45 $3,601.47

1.3 INCREMENTAL COST ANALYSIS (ICA)

1.3.1 Incremental Cost Analysis Process

Incremental cost analysis is conducted on the remaining alternatives. This consists of

several iterative steps where the incremental difference in both cost and output (AAHUs)

are computed. Incremental cost is the additional cost incurred by selecting one

alternative over another alternative, and is computed by subtracting the cost of one

alternative under consideration from the cost of another alternative under consideration.

Similarly, incremental output is the additional output generated by selecting one

alternative over another alternative, and is computed by subtracting the output of one

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alternative under consideration from the output of another alternative under

consideration. The first step is compute the incremental change in cost and incremental

change in output from implementing each remaining alternative over the No Action

Alternative, where the No Action Alternative is considered the baseline condition against

which each remaining cost effective alternative is compared. Next, the alternative

yielding the lowest incremental cost per unit over the No Action Alternative is identified.

In other words, this identified alternative is the most cost effective remaining alternative

for production of AAHUs over the No Action Alternative. After identifying this

alternative with the lowest incremental cost per unit (i.e., the most cost efficient from a

production perspective, producing output at the lowest unit cost), any alternatives (shown

in italics) generating a lower output level are removed from further consideration in the

ICA process. The eliminated alternatives are less efficient in production, producing a

lower level of output at a higher incremental unit cost. For example, in Table K6,

Alternative 8, in italics, is removed from further consideration in the ICA process. The

remaining alternatives are further evaluated via repeated steps of this incremental ICA

process, where the most cost effective remaining alternative becomes the new baseline

condition against which each remaining cost effective alternative is compared. This

iterative process continues until only the most cost effective, production efficient

alternatives remain. When the most cost effective remaining alternative is the last

alternative evaluated, there is no need for further incremental cost analysis; the ICA

process is complete. The following steps display the progression through the ICA

process, resulting in the remaining Best Buy alternatives (Table K8).

Table K5: LCA-ARTM: Step 3

Baseline: No Action Plan

Net AAHUs

Average

Annual

Incremental

Cost

Incremental

Net AAHUs

Average Annual

Incremental

Cost per Unit

Alternative (AAHU)

Average

Annual

Cost

Alt. 1 (No Action) N/A 0 N/A N/A N/A

Alt. 7 $260,595 243.20 $260,595 243.20 $1,071.53

Alt. 8 $4,747,577 1,214.19 $4,747,577 1,214.19 $3,910.06

Alt. 2 $10,535,704 3,219.90 $10,535,704 3,219.90 $3,272.06

Alt. 3 $11,976,509 3,325.45 $11,976,509 3,325.45 $3,601.47

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Table K6: LCA-ARTM: Step 4

Baseline: Last Selected Plan

(Alt. 7)

Net AAHUs

Average

Annual

Incremental

Cost

Incremental

Net AAHUs

Average Annual

Incremental

Cost per Unit

Alternative (AAHU)

Average

Annual

Cost

Alt. 1 (No Action) N/A 0 N/A N/A N/A

Alt. 7 $269,595 243.20 $260,595 243.20 $1,071.53

Alt. 8 $4,747,577 1,214.19 $4,486,962 970.99 $4,621.02

Alt. 2 $10,535,704 3,219.90 $10,275,109 2,976.70 $3,451.85

Alt. 3 $11,976,509 3,325.45 $11,715,914 3,082.25 $3,801.09

Table K7: LCA-ARTM: Step 5

Baseline: Last Selected Plan

(Alt. 2)

Net AAHUs

Average

Annual

Incremental

Cost

Incremental

Net AAHUs

Average Annual

Incremental

Cost per Unit

Alternative (AAHU)

Average

Annual

Cost

Alt. 1 (No Action) N/A 0 N/A N/A N/A

Alt. 7 $260,595 243.20 $260,595 243.20 $1,071.53

Alt. 2 $10,535,704 3,219.90 $10,275,109 2,976.70 $3,451.85

Alt. 3 $11,976,509 3,325.45 $1,440,805 105.55 $13,650.45

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Table K8: LCA-ARTM: Step 6

Best Buy Plans

Net AAHUs

Average

Annual

Incremental

Cost

Incremental

Net AAHUs

Average Annual

Incremental

Cost per Unit

Alternative (AAHU)

Average

Annual

Cost

Alternative. 1 (No

Action) N/A 0 N/A N/A N/A

Alternative 7 $260,595 243.20 $260,595 243.20 $1,071.53

Alternative 2 $10,535,704 3,219.90 $10,275,109 2,976.70 $3,451.85

Alternative 3 $11,976,509 3,325.45 $1,440,805 105.55 $13,650.45

1.3.2 Results of the CE/ICA Process

As presented in Table K8, the remaining cost effective, production efficient Alternatives

are known as Best Buy Plans. These Plans can be used to determine the desired project

scale for environmental restoration planning. Characteristic of Best Buy Plans, the

average annual incremental cost per unit increases for successive larger levels of

incremental output (AAHUs).

Alternative 7 provides 243.20 total AAHUs at an average annual cost of $260,595, and

an average annual incremental cost per unit (AAHU) of $1,071.53 for each of the 243.20

AAHUs. Alternative 2 provides 3,219.90 total AAHUs, at an average annual cost of

$10,535,704, and an average annual incremental cost per unit of $3,451.85 for each of the

additional 2,976.70 AAHUs over Alternative 7. Alternative 3 provides 3,325.45 total

AAHUs at an average annual cost of $11,976,509, and an average annual incremental

cost per unit of $13,650.45 for each of the additional 105.55 AAHUs over Alternative 2.

The first best buy plan is the most efficient plan from an incremental cost per AAHU

perspective. However, if a higher level of output (AAHUs) is desired than that provided

by the first best-buy plan, the second best buy plan becomes the most efficient plan for

producing additional output, and so on. The recommended Best Buy Plan is Alternative

2, generating 3,219.90 total AAHUs at an average annual investment cost of

$10,535,704, and a first cost of $203,047,200.

Figure K1 displays the relation of Output (AAHUs) to Average Annual Cost, while

Figure K2 displays the relation of Output (AAHUs) to Incremental Cost per Unit

(AAHU).

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Figure K1: CE/ICA of Non-Cost Effective, Cost Effective and Best Buy Alternatives

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Figure K2: ICA of Best Buy Plans

1.4 OTHER FACTORS

1.4.1 Navigation Effects

The Houma Navigation Canal (HNC) is a 40.5 miles channel with authorized dimensions

of 15 feet deep by 150 feet wide from Houma to mile zero and 18 feet deep by 300 feet

wide to the 18-foot contour of the Gulf of Mexico. A lock structure located along the

Canal consists of a 250-foot wide floodgate and a 200-foot lock. Typically the floodgate

is secured in the open position, allowing vessel traffic to transit thru the gate opening.

The recommended Alternative would require closure of this gate, forcing vessel traffic to

transit the Canal via the lock. The effects of such a gate closure on potential navigation

delays were analyzed and evaluated under the navigation section of the Economic

Appendix of the 2002 Final Feasibility Report for the Mississippi River and Tributaries,

Morganza, Louisiana to the Gulf of Mexico, Hurricane Protection. As noted in the 2002

Report, historically traffic on the Houma Canal has been roughly the same since 1992,

where variations in tonnage can be tied directly to the fortunes of the oil and gas industry.

Any changes in traffic would be associated with new finds in the Gulf of Mexico and/or

new facilities within the Canals service area. Therefore, for this report as was the case

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for the 2002 Report, 1995 traffic patterns and total volumes are used as the typical year

for both with and without project conditions, and are held constant over the project life

for purposes of this analysis. Implementation of Alternative #2 would increase annual

closure duration of the floodgate from two months (No Action Alternative) to twelve

months, thereby delaying 10 months of HNC traffic. Assuming Houma Canal vessel

traffic patterns as described here, transiting the 200-foot wide lock due to closure of the

floodgate is estimated to generate average annual navigation delay costs during this 10-

month closure period of approximately $240,600, which is considered an upper bound

estimate. Therefore, navigation effects along the Houma Canal given closure of the

floodgate are estimated as minimal if not negligible to the vessel traffic industry. As a

perspective, the 2002 Report estimates an extended halt to navigation within the Canal

would halt all traffic and demand relocation by oil platform manufacturing industries,

resulting in NED impacts estimated in excess of $100 million. Navigation delay costs of

$240,600 generated under the implementation of the recommended Alternative would

therefore be approximately two-tenths of one percent of the $100 million navigation

delay figure estimated under extended navigation interruption. Additional details are

provided in the March 2002 Final Feasibility Report.

1.4.2 Acceptability, Completeness, Effectiveness, and Efficiency

Alternative Plan 3 meets the four evaluation criteria of the Economic and Environmental

Principles and Guidelines for Water and Related Land Resources Implementation

Studies. Special consideration is also given to these criteria within the larger context of

the LCA Report (2004). The four criteria are acceptability, completeness, effectiveness,

and efficiency.

Acceptability. The plan is acceptable to Federal, state, tribal, local entities, and the public.

It is compatible with existing laws, regulations, and policies.

Completeness. The plan is complete. Realization of the plan does not depend on

implementation of actions outside the plan.

Effectiveness. The plan is effective. It addresses most of the project objectives. It

improves marsh habitat by restoring deltaic process related to freshwater, nutrient and

sediments.

Efficiency. The plan is efficient. It is a cost-effective solution to the stated problems and

objectives. No other plan produces the same level of output more cost effectively. The

plan is cost effective and provides the greatest increase in benefits for the least increase in

cost.

1.4.3 Recommended Plan

The PDT recommends Alternative Plan 2 as the recommended plan (RP).

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This alternative best meets the study objectives. It would result in restoration of deltaic

processes within the project area. In cooperation with the USFWS, NOAA, and the State

of Louisiana the Corps has planned and would design a project that serves the needs of

the nation.

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APPENDIX L:

Engineering Appendix

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Volume III

APPENDIX L:

5 Engineering

Convey Atchafalaya River to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

10 Final Feasibility Report

Appendix L  Engineering Investigations and Cost Estimates

Table of Contents

L1 GENERAL......................................................................................................................... 7

15 L2 HYDRAULICS AND HYDROLOGY ............................................................................ 8

L2.1 CLIMATOLOGY ............................................................................................................................................8

L2.1.1 Climate 8

L2.1.2 Temperature 8

L2.1.3 Precipitation 8

20 L2.1.4 Wind 9

L2.1.5 Stream Gaging Data 11

L2.1.6 Floods of Record 13

L2.1.7 Tides 15

L2.2 HYDRAULIC MODELING ............................................................................................................................15

25 L3 SURVEYING, MAPPING, AND GEOSPATIAL DATA REQUIREMENTS ......... 15

L3.1 GEOSPATIAL DATA....................................................................................................................................15

L3.2 AERIAL PHOTOGRAPHY.............................................................................................................................19

L3.2.1 2008 Digital Orthophoto Quarter Quadrangles 19

L3.2.2 2002 LDEQ Landsat Enhanced Thematic Mapper Pan-Sharpened Mosaic of Louisiana UTM15 NAD83, (2002)

30 MrSID 19

L3.2.3 2002 Louisiana Federal Emergency Management Agency (FEMA) LIDAR 20

L3.3 GROUND TOPOGRAPHIC SURVEYS.............................................................................................................20

L4 GEOLOGY...................................................................................................................... 20

L4.1 GEOLOGIC SETTING OF STUDY AREA........................................................................................................21

35 L4.3 GROUNDWATER ........................................................................................................................................22

L5 GEOTECHNICAL INVESTIGATIONS AND DESIGN............................................ 22

L5.1 GENERAL...................................................................................................................................................22

L5.2 FIELD INVESTIGATION...............................................................................................................................23

L5.3 LABORATORY TESTING .............................................................................................................................23

40 L5.4 FOUNDATION DESIGN................................................................................................................................24

L5.4.1 Slope Stability Analyses (SS) 24

L5.4.2 Individual Features SS 25

L5.4.3 Bedding for Culverts 26

L5.4.4 Pile Foundation 26

45 L5.4.5 Construction Excavation 27

L5.4.6 Hydrostatic Uplift 27

L6 ENVIRONMENTAL ENGINEERING ........................................................................ 43

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L6.1 HAZARDOUS, TOXIC AND RADIOACTIVE WASTES......................................................................43

L7 CIVIL DESIGN CRITERIA.......................................................................................... 43

50 L7.1 GENERAL...................................................................................................................................................43

L7.1.1 Surveys 43

L7.1.2 Right-of-Way (ROW) 43

L7.2 FEATURE DESIGNS ....................................................................................................................................43

L7.2.1 STRUCTURES 43

55 L7.2.3 SHORELINE PROTECTION 44

L7.2.4 DREDGED CHANNELS 44

L7.2.5 WEIRS 44

L7.2.6 PLUGS 44

L7.2.7 TERRACING 45

60 L7.2.8 CULVERTS 45

L7.2.9 REMOVALS 45

L7.2.10 SPOIL GAP 45

L7.2.11 MARSH BERM 45

L7.2.12 MARSH CREATION (BENEFICIAL USE OF DREDGE CHANNEL SPOIL) 46

65 L8 STRUCTURAL DESIGN CRITERIA.......................................................................... 46

L8.1 FOUNDATION RECOMMENDATIONS...............................................................................................46

L8.1.1 GENERAL 46

L8.1.2 DESCRIPTION OF FEATURE FOUNDATIONS 47

L8.2 STRUCTURAL DESIGN FOR DIVERSION FACILITY.......................................................................48

70 L8.2.1 GENERAL 48

L8.2.2 DESCRIPTION OF STRUCTURAL FEATURES 48

L9 ELECTRICAL AND MECHANICAL REQUIREMENTS ....................................... 53

L9.1.1 ELECTRICAL SOURCES AND SUPPLY REQUIREMENTS..........................................................53

GENERAL 53

75 L9.1.2 ELECTRICAL REQUIREMENTS PER SITE 54

L9.2 SOLAR POWER SUPPLY SYSTEMS....................................................................................................54

L9.2.1 GENERAL 54

L9.3 ELECTRICAL AND MECHANICAL DESIGN FOR DIVERSION FACILITY ....................................54

L9.3.1 GENERAL 54

80 L9.3.2 ELECTRICAL/MECHANICAL REQUIREMENTS PER SITE 55

L10 OPERATIONS AND MAINTENANCE....................................................................... 56

L11 COST ESTIMATES ....................................................................................................... 56

L11.1 BASIS OF COST ESTIMATE .........................................................................................................................56

L11.1.1 Equipment Cost 56

85 L11.1.2 Labor Cost 56

L11.1.3 Dredge Cost 57

L11.1.4 Estimate Documents 57

L11.1.5 Areas of Consideration for Cost 57

L11.2 CONTINGENCIES ........................................................................................................................................57

90 L11.3 PLANNING, ENGINEERING AND DESIGN.....................................................................................................57

L11.4 CONSTRUCTION MANAGEMENT ................................................................................................................58

L11.5 DETAILED ESTIMATE.................................................................................................................................58

L11.6 RISK ANALYSIS .........................................................................................................................................58

L12 CONSTRUCTION SEQUENCE................................................................................... 58

95 L12.1 GENERAL...................................................................................................................................................58

L13 ANNEXES ....................................................................................................................... 61

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List of Figures

FIGURE L1  MAP OF STUDY AREA..................................................................................... 8

FIGURE L2 - CLIMATE STATIONS...................................................................................... 10

FIGURE L3 - STREAM GAGING STATIONS...................................................................... 12

105 FIGURE L4 - GEOTECHNICAL BORING DATA FOR BORING HNCL-32U (02-06)... 29

FIGURE L5 - GEOTECHNICAL BORING DATA FOR BORING CN99-3U (99-527)..... 30

FIGURE L6 - GEOTECHNICAL BORING DATA FOR BORING BLK-8U (03-17885). 31

FIGURE L7 - GEOTECHNICAL BORING DATA FOR BORING CN07-2U (07-19678). 32

FIGURE L8 - GEOTECHNICAL BORING DATA FOR 12-AIUT (84-18) ........................ 33

110 FIGURE L9 - WD3 Q-CASE..................................................................................................... 34

FIGURE L10 - EC5 BANKS...................................................................................................... 35

FIGURE L11 - S-CASE.............................................................................................................. 36

FIGURE L12 - ES2 S-CASE...................................................................................................... 37

FIGURE L13 - EC3 GLOBAL STABILITY............................................................................ 38

115 FIGURE L14 - Q-CASE PILE CAPACITY ............................................................................ 39

FIGURE L15 - S-CASE PILE CAPACITY ............................................................................. 40

FIGURE L16 - Q-CASE PILE CAPACITY ............................................................................ 41

FIGURE L17 - S-CASE PILE CAPACITY ............................................................................. 42

FIGURE L18 - CONSTRUCTION SCHEDULE .................................................................... 59

120 FIGURE L19 - CONSTRUCTION SCHEDULE (PAGE 2) .................................................. 60

FIGURE L20 - CONSTRUCTION SCHEDULE (PAGE 3) ...... ERROR! BOOKMARK NOT

DEFINED.

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125 List of Tables

TABLE L1 - MEAN MONTHLY AND ANNUAL TEMPERATURES (°F).......................... 8

TABLE L3 - MONTHLY AND ANNUAL PRECIPITATION (INCHES)............................. 9

TABLE L4 - STREAM GAGING DATA................................................................................. 11

130 TABLE L5  GEOTECHNICAL ANALYSIS PERFORMED .............................................. 22

TABLE L6 - SUMMARY OF MECHANICAL PROPERTIES FOR BORINGS USED.... 24

TABLE L7 - TYPICAL VALUES FOR SILTS, SANDS AND RIP RAP ............................. 25

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L1 GENERAL

135 The LCA-ARTM Study Area (Figure L1) comprises approximately 1000 square miles (~660,000

acres) in Southern Louisiana in the vicinity of the City of Houma and Terrebonne Parish. The

LCA-ARTM study area fits into the Louisiana Coastal Area Ecosystem Restoration Study (LCA

Study) Area, which has been identified as the Louisiana coastal area from Mississippi to Texas.

The proposed LCA-ARTM project is located in the Deltaic Plain within Subprovince 3, one of

140 the four Subprovinces identified in the LCA Study Area.

The overall study area is bound to the west by the Lower Atchafalaya River. The study area is

bound to the east by the Bayou Lafourche ridge. The study area is bound to the north by the

Bayou Black ridge, from the Lower Atchafalaya River to the City of Houma, and by the Gulf

145 Intracoastal Waterway (GIWW), from the City of Houma to the Bayou Lafourche ridge. The

southern boundary of the project was based on a delineation conducted in 2007 of coastal

Louisiana vegetation types. The boundary identifies the transition between saline and brackish

marsh types identified by Sasser et al. (2008).

150 Eight alternatives, including the No Action alternative were formulated to address the goals and

objectives of the study. These alternatives included 62 features dispersed throughout the project

area. These features include various water control structures, dredged channels, culverts, weirs,

plugs, terracing, marsh berms, spoil gaps, bank line protection, and removal of existing

structures.

155

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Figure L1  Map of Study Area.

L2 HYDRAULICS AND HYDROLOGY

160

L2.1 Climatology

L2.1.1 Climate

The climate of the area is humid subtropical and is subject to significant polar influences during

165 the winter as cold air masses periodically move southward over the area displacing warm moist

air. Prevailing southerly winds create a strong maritime character. This movement from the Gulf

of Mexico helps to decrease the range between hot and cold temperatures and provides a source

of abundant moisture and rainfall.

170 L2.1.2 Temperature

Records of temperature are available from "Climatography of the United States No. 81" for

Louisiana, published by the National Climatic Data Center. The study area can be described by

using the normal temperature data observed at three stations located within the study area. These

stations are shown in Table L1 with the monthly and annual mean normals based on the period

1971-2000. The average annual mean normal temperature is 68.5 degrees Fahrenheit (o 175 F), with

monthly mean temperature normal varying from 82.5°F in July to 51.8o

F in January.

Table L1 - Mean Monthly and Annual Temperatures (°F)

30 Year Normals (1971 - 2000)

Station JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN

Galliano 53.0 55.7 62.3 67.9 75.1 80.1 81.9 81.8 78.5 69.9 62.2 55.3 68.6

Houma 53.1 56.2 62.7 68.4 75.8 80.7 82.5 82.3 78.9 69.9 62.1 55.4 69.0

Morgan

City 51.8 54.8 61.2 67.4 74.5 79.6 81.5 81.2 78.2 70.0 61.3 54.6 68.0

180 A maximum extreme temperature of 102°F was recorded at Morgan City during July 1980 and a

minimum extreme of 4°F was recorded during December 1971 at Morgan City. Figure L2 shows

the location of the climate gages.

L2.1.3 Precipitation

185 Records of precipitation are also available in publications by the National Climatic Center. Three

stations have been used to show the rainfall data for the study area (these stations are shown on

Figure L2). Table L2 gives a list of the stations with their period of record and available

extremes. Three of these stations have 30-year monthly and annual normals. The average annual

normal rainfall of these stations is 64.14 in. based over the period 1961-1990. Table L3 lists the

190 monthly and annual normals. The wettest month is July with an average monthly normal of 7.71

in October is the driest month averaging 3.47 in.

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Table L2 - Precipitation Extremes

Station

Period Maximum Minimum Greatest

of Record Monthly Date Monthly Date 1-Day Date

(to 2001) (in) (in) (in)

Galliano 1968 - Date 21.35 09/98 0.12 10/78 9.90 5/30/1975

Houma 1930 - Date 20.84 05/91 0.00 10/78 11.35 5/31/1959

Morgan City 1930 - Date 18.82 05/91 0.01 10/78 10.02 5/9/1995

195 Table L3 - Monthly and Annual Precipitation (inches)

30 Year Normals (1971 - 2000)

Station JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN

Galliano 5.85 4.59 5.53 4.43 5.75 5.82 7.69 7.13 6.34 3.65 4.67 4.03 65.48

Houma 5.43 4.59 4.96 4.46 5.35 5.96 7.85 6.73 6.28 3.11 4.55 4.40 63.67

Morgan

City 5.81 4.39 4.70 4.22 5.38 5.81 7.60 7.40 6.49 3.66 5.07 4.95 65.48

L2.1.4 Wind

The average wind speed in the study area is 7.9 miles per hour (mph), based on the period 1973-

1998 at New Orleans Moisant Airport. Southeast winds predominate in the spring and fall while

200 the fall and winter's prevailing wind direction is from the northeast. Winter storms in the area

have produced wind speeds of up to 47 mph. The summer is often disturbed by tropical storms

and hurricanes that produce the highest winds in the area. The maximum wind speed observed

(highest one-minute speed) since 1963 was 69 mph, and was caused by Hurricane Betsy in

September 1965.

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205

Figure L2 - Climate Stations

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L2.1.5 Stream Gaging Data

Stream gaging data are available from eight major stations in the study area. Some stations are

210 maintained through a cooperative agreement between the U.S. Army Corps of Engineers and the

U.S. Geological Survey. The stations with their maximum and minimum stages and available

discharges are shown in Table L4. The station locations are shown on Figure L3.

Table L4 - Stream Gaging Data

Station

Period of

Record

Maximum Stage Minimum Stage

(ft)

NGVD Date (ft) NGVD Date

Bayou Lafourche

at Thibodaux 1966 - Present i 9.8 6/7/2001 -0.4 12/2/1966

Bayou Grand Caillou

at Dulac 1984 - Present i 8.89 10/28/1985 - -

Houma Navigation Canal

at Dulac 1992 - Present 7.17 9/12/2008 -1.42 1/8/1996

GIWW

at Houma 1997 - Present 4.87 9/13/2008 -0.34 12/15/1997

Bayou Boeuf

at Amelia 1955 to Present i 4.9 4/30/1975 DRY 1/20/1940

Bayou Boeuf (Lock)

West 1954 - Present 10.56 5/27/1973 -1.98 11/8/1959

East 1954 - Present 4.68 4/17/1973 -1.14 12/24/1989

Lower Atchafalaya River

at Morgan City 1905 - Present 10.53a 8/25/1992 -5.44c 8/25/2026

Station

Period of

Record

Maximum

Discharge Minimum Discharge

cfs Date cfs Date

Bayou Lafourche

at Thibodaux 1984 - Present 1,450 5/9/1995 - -

Lower Atchafalaya River

at Morgan City 1976 - Present i 741,000 6/8/2027 -151,000 10/3/2003

i Intermittently a From incomplete records

215

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Figure L3 - Stream Gaging Stations

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220 L2.1.6 Floods of Record

The study area floods from tidal surges associated with hurricanes and tropical storms. Lower

Atchafalaya River waters enter the study area from the Avoca Island Cutoff Channel and the

GIWW. Heavy rainfall also affects highly developed areas.

225 Some of the major historical floods caused by heavy rainfall or tides occurred in 1973, 1980,

1983, and 1991. A description of these significant floods follows.

1973 Flood: Flooding occurred throughout the eastern portion of the study area during the spring

of 1973. Below Highway 90, tidal flooding inundated nearly all areas except the alluvial ridges

230 of the Mississippi River, Bayou Lafourche, and the many smaller streams that drain into the Gulf

of Mexico. Peak stages recorded on May 27 include 11.16 (ft), NGVD at Wax Lake Outlet at

Calumet and 6.27 ft, NGVD at Lower Atchafalaya River below Sweet Bay Lake. On May 28,

flooding caused a high stage of 10.53 ft, NGVD on the Lower Atchafalaya River at Morgan City.

235 1980 Flood: Heavy rains at the end of March and early April setup flooding which occurred over

the study area during mid April. A maximum extreme was set at Bayou Black at Greenwood

(4.82 ft, NGVD). Some of the one-day rainfall totals on April 13 were 9.1 in. at Morgan City and

11.8 in. at Thibodaux.

240 1983 Flood: Heavy rains north of the study area produced this flood. In the Atchafalaya Basin

Floodway System, peak stages from this event include 8.11 ft, NGVD at Wax Lake Outlet at

Calumet and 7.32 ft, NGVD at Lower Atchafalaya River at Morgan City, both on June 6.

1991 Flood: Flooding occurred throughout the study area due to above normal rainfall during

245 most of the year. One example of this flooding occurred in the Houma-Thibodaux area during

May 8-10. Three-day totals at these two sites were 12.94 and 14.33 in., respectively. The rainfall

event set a maximum extreme stage of 8.76 ft, NGVD on Bayou Lafourche at Thibodaux gage

on May 9. In addition to heavy rainfall, high tides in the Gulf of Mexico affected runoff.

250 Some of the major historical hurricanes that affected the study area were in 1909, 1915, 1956

(Flossy), 1957 (Audrey), 1961 (Carla), 1964 (Hilda), 1974 (Carmen), 1985 (Juan), and 1992

(Andrew). A description of these significant storms follows.

1909 Flood: Wind speeds of 80 mph were reported for Thibodaux and for the mouth of Bayou

255 Terrebonne, 40 miles south of Thibodaux, as a tropical cyclone passed through the study area

from September 19-20. The highest tides were experienced at the mouth of Bayou Terrebonne in

Lafourche Parish, where an elevation of 15 ft above sea level was attained at Sea Breeze.

1915 Flood: Heavy rainfall, high winds, and extremely low barometric pressures from this

260 hurricane from 29 September- 2 October caused headwater flooding along Bayou Lafourche

where stages of 9 and 5 ft above sea level, respectively, were reported at Leeville and Golden

Meadow. The U.S. Weather Bureau 5-minute sustained and extreme wind velocities for the 29

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September were 66 and 75 miles per hour at New Orleans. In Leeville, approximately 13 miles

west of Grand Isle, only 1 of the 100 houses remained standing as a result of this storm.

265

1956 Flood: Hurricane Flossy, during the period September 21-30, was the cause of this flood.

Tides reached 5 to 8 ft above normal along most of the southeastern coast. Rainfall during the

storm was quite heavy. The heaviest occurred at Golden Meadow where 16.7 in. of rain was

recorded.

270

1957 Flood: Heavy rainfall and high winds associated with Hurricane Audrey, June 25-28,

caused headwater flooding along the Louisiana coast. The storm set peak stages of 8.05 ft

NGVD at Lower Atchafalaya River Below Sweet Bay Lake, 6.81 ft NGVD at Atchafalaya Bay

at Eugene Island, 8.52 ft and 7.35 ft, NGVD respectively at IWW at Wax Lake East and West on

275 June 27. Maximum stages were also set along the coastline on this date and included 6.00 ft

NGVD at Schooner Bayou and 8.12 ft NGVD at Leland Bowman Lock.

1961 Flood: Hurricane Carla raised tides 3 to 4 ft above normal along the entire coastline of

Louisiana during the period September 4-14. Rainfall associated with the hurricane amounted to

280 6.2 in. at Morgan City and 3.4 in. at Houma.

1964 Flood: Hurricane Hilda, during the period October 3-5, caused extensive tidal and

headwater flooding in the study area. Heavy rainfall north of the study area associated with this

hurricane ranged from 10.1 in. at New Roads to 8.9 in. at Baton Rouge.

285

1974 Flood: Hurricane Carmen was responsible for this flood during September 5-9. The highest

known storm tide, 11.64 ft, NGVD occurred at Cocodrie in Terrebonne Parish. This stage was

reportedly more than 10 ft above normal.

290 1985 Flood: Hurricane Juan, during the period October 27-31, caused massive flooding

throughout the study area due to its prolonged 5-day stay along the Louisiana coast. Tides were

generally 3 to 6 ft above normal, and storm surges of 5 to 8 ft were reported in several coastal

parishes. Rainfall amounts in the study area ranged from 5 to nearly 17 in. for this period.

295 1992 Flood: Hurricane Andrew, during the period August 24-27, set new maximum extreme of

7.65 ft, NGVD at Round Bayou at Deer Island and recorded 6.8 ft, NGVD for the Lower

Atchafalaya River at Morgan City. The Intracoastal Waterway at the Wax Lake East Control

Structure recorded a stage of 6.15 ft, NGVD.

300 2002 Flood: Hurricane Lili, a major hurricane over the Gulf of Mexico, during the daylight

hours of October 2, 2002 moved steadily northwest around 15 mph toward the Louisiana coast

during the evening hour. The hurricane weakened rapidly to a Category 1 Hurricane by the time

it made landfall during the morning of October 3rd along the south central Louisiana coast.

Storm surge tides were 4 to 7 feet above normal across south Lafourche and Terrebonne

305 Parishes. Heavy rainfall was not widespread, in part due to the rapid movement of the hurricane

away from the area.

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2005 Flood: Hurricane Rita impacted the project area from on September 23  24. Across

southeast Louisiana, the main affect from Hurricane Rita was the substantial storm surge

310 flooding that occurred in low lying communities across coastal areas of southern Terrebonne,

southern Lafourche, and southern Jefferson Parishes where numerous homes and businesses

were flooded. Some of the most substantial damage occurred in southern Terrebonne Parish

where storm surge of 5 to 7 feet above normal overtopped or breached local drainage levees

inundating many small communities.

315

L2.1.7 Tides

Tides are diurnal and range from 1.5 to 2.0 ft Inland, the extent of tidal range and area of

influence are determined by the rainfall flow exiting the drainage areas into the Gulf of Mexico

and by flows in the GIWW originating in the Atchafalaya River. Mean tide ranges are 1.3 ft at

320 Cocodrie and 0.9 ft at Leeville; inland at Houma the mean tide range is only 0.2 ft. During a

spring tidal cycle these ranges will be larger; during a neap tidal cycle these ranges will be less.

L2.2 Hydraulic Modeling

RMA-2 and RMA-11 modeling was performed on the entire project area utilizing the Resource

325 Modeling Associates versions of the models. Model extents were the Atchafalaya River to the

west, the Mississippi River to the east, the Gulf of Mexico to the south, and the Bayou Black

ridge and other hydrologic barriers to the north. The model was calibrated to the period of

October to November 2004.

330 Alternatives analysis included high and low Atchafalaya River conditions runs. Results of these

runs were used to develop yearly hydrographs using monthly averaged values for select locations

throughout the project area. The same procedure was used for salinity and stage values. Model

results were provided to the environmental team for use in benefits analysis.

335 A detailed description of the modeling effort and its results can be found in Annex 2 to this

Appendix.

L3 SURVEYING, MAPPING, AND GEOSPATIAL DATA REQUIREMENTS

340

L3.1 Geospatial Data

The geometry representing proposed features in the maps and the Engineering plan views were

created using ArcGIS 9.3. This project consisted of new features developed by the Project

Development Team and of other features developed by previous projects. Due to features being

345 incorporated from other projects into this project, different horizontal coordinate systems were

used to create the data. The two coordinate systems used for data creation were; NAD 1983

UTM Zone 15N and NAD 1983 StatePlane Louisiana South FIPS 1702 ft. The United States

Army Corps of Engineers St. Louis & New Orleans District and the Louisiana Department of

Wildlife and Fisheries created the above mentioned new geometry in 2009 and 2010. The data

350 were created using the 2008 Digital Orthophoto Quarter Quadrangles as a reference, for further

information on the photography see C. 3.2 Aerial Photography.

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The United States Army Corps of Engineers St. Louis District created salinity point data, flow

rate data, water surface elevation data, and the hydraulic matrix for this project. The data were

355 created in the hydraulic modeling process of the project. For any further information on the data

see the Hydraulic Engineering Annex to this Appendix.

The United States Army Corps of Engineers New Orleans District created similarity zones and

historic districts data for this project. The data was created in the Cultural and Natural Resources

360 Section of the Environmental Branch. For any further information on the data see the 4.2.13

Aesthetics section of this report.

ArcGIS software provided the capabilities of transforming the data and aerial photography into

one uniform coordinate system for analysis of features and map production. The uniform

365 coordinate system used for these tasks was NAD 1983 StatePlane Louisiana South FIPS 1702 ft.

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Reference Data:

Boring Logs. Louisiana: United States Army Corps of Engineers  New Orleans District, 2009.

370 Cities. United States Army Corps of Engineers  New Orleans District, 2009.

Communities. Louisiana: State of Louisiana, 2009.

District Boundary. Louisiana: United States Army Corps of Engineers  New Orleans District,

2009.

Eco Regions. Louisiana: State of Louisiana, 2009.

375 Existing Land Use. Louisiana: State of Louisiana, 2009.

Federal and Local Levees. Louisiana: Terrebonne Parish Consolidated Government, 2009.

Federal and Local Levees. Louisiana: United States Army Corps of Engineers  New Orleans

District, 2009.

General Base Data. Tele Atlas North America, 2007.

380 Hurricane Tracks. National Oceanic and Atmospheric Administration Coastal Services Center,

2009.

Hydrography. Louisiana: State of Louisiana, 2009.

Hydrography. Louisiana: United States Army Corps of Engineers  New Orleans District, 2009.

Landowners. Louisiana: Terrebonne Parish Consolidated Government, 2009.

385 Land Gain/Loss Rates. United States Geological Survey, 2009.

National Forests. Louisiana: State of Louisiana, 2009.

National Parks. Louisiana: State of Louisiana, 2009.

National Wildlife Refugees. Louisiana: State of Louisiana, 2009.

National Wildlife Refugees. Louisiana: United States Army Corps of Engineers  New Orleans

390 District, 2009.

Oil and Gas Infrastructure. Louisiana: Louisiana Department of Natural Resources Strategic

Online Natural Resources Information System, 2009.

Oyster Seed Grounds and Leases. Louisiana: Louisiana Department of Wildlife and Fisheries,

2009.

395 Parish Boundaries. Louisiana: State of Louisiana, 2009.

Parish Boundaries. Louisiana: United States Army Corps of Engineers  New Orleans District,

2009.

Soils. Louisiana: United States Army Corps of Engineers  New Orleans District, 2009.

State Parks. Louisiana: State of Louisiana, 2009.

400 State Parks. Louisiana: United States Army Corps of Engineers  New Orleans District, 2009.

Thoroughfares. Louisiana: State of Louisiana, 2009.

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Urban Centers. Louisiana: State of Louisiana, 2009.

USGS Habitat Classifications. United States Geological Survey & National Wetlands Research

Center, 2009.

405 Utilities. Louisiana: Terrebonne Parish Consolidated Government, 2010.

Wildlife Management Areas. Louisiana: State of Louisiana, 2009.

Wildlife Management Areas. Louisiana: United States Army Corps of Engineers  New Orleans

District, 2009.

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410 L3.2 Aerial Photography

L3.2.1 2008 Digital Orthophoto Quarter Quadrangles

The 2008 Digital Orthophoto Quarter Quadrangles (DOQQs) were provided by the United States

Army Corps of Engineers New Orleans District. The following information is provided in the

metadata of the DOQQ data set. This data set was produced in accordance with USGS Standards

415 for Digital Orthophotos, 1996. Review was provided by the USGS National Geospatial

Technical Operations Center (NGTOC). The data set was created by Photo Science, Inc. in 2009

for the USGS National Wetlands Research Center and CWPPRA Task Force.

The horizontal coordinate system is projected coordinate system NAD 1983 UTM Zone 15N.

420 The DOQQ horizontal positional accuracy and the assurance of that accuracy depend, in part, on

the accuracy of the data inputs to the rectification process. These inputs consist of the digital

elevation model (DEM), aerotriangulation control and methods, sensor calibration, and aerial

imagery that meet National Aerial Photography Program (NAPP) standards. The vertical

accuracy of the verified USGS format DEM is equivalent to or better than a USGS level 1 or 2

425 DEM, with a root mean square error (RMSE) of no greater than 7.0 meters. Field control is

acquired by third-order class 1 or better survey methods sufficiently spaced to meet National

Map Accuracy Standards (NMAS) for 1:12,000-scale products. Photo-identifiable ground test

points are identified in the orthorectified image and measured. The image coordinates are

compared to the known positions of these points and the radial differences for each point

430 computed. A radial RMSE value is then calculated for the DOQQ. Note: Adjacent DOQQ's,

when displayed together in a common planimetric coordinate system, may exhibit positional

discrepancies across common DOQQ boundaries. Linear features, such as streets, may be offset

between images. However, these edge mismatches still conform to NMAS positional horizontal

accuracy requirements. The estimated accuracy is 3.34 meters which was determined by the

435 Federal Geographic Data Committee, 1998, Geospatial Positioning Accuracy Standard, Part 3,

National Standard for Spatial Data Accuracy, FGDC-STD-007.3-1998.

L3.2.2 2002 LDEQ Landsat Enhanced Thematic Mapper Pan-Sharpened Mosaic of

Louisiana UTM15 NAD83, (2002) MrSID

440 The 2002 Landsat Imagery was provided by the United States Army Corps of Engineers New

Orleans District. The following information is provided in the metadata of the Landsat data set.

The horizontal coordinate system is projected coordinate system NAD 1983 UTM Zone 15N.

This data set is a satellite image of the lands and waters of the State of Louisiana. It was created

445 by combining fourteen scenes of 30-meter resolution Landsat Thematic Mapper (TM) imagery

with 15-meter resolution panchromatic imagery. The TM and panchromatic imagery for each

scene are coincident. The original image data were geo-rectified and resampled using cubic

convolution to 25-meter (TM) and 12.5-meter (pan) cells by the Earth Resources Observation

Systems (EROS) Data Center. These data were purchased from EROS by the Louisiana

450 Department of Environmental Quality (northern half of state) and the USGS's National Wetlands

Research Center Lafayette (southern half of state.) The processing to produce a seamless

enhanced image was performed at LDEQ by a LDEQ contractor. The work was funded by a

grant from the US EPA to the LDEQ Non-Point Source Water Pollution Section. The image was

constructed from a red, green, blue (RGB) composite of bands 7,5 & 3 fused with the

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455 panchromatic image to produce the enhanced TM pan sharpened mosaic. The merged satellite

image was produced to support on-going research for the LDEQ Non-point Source Program by

providing a more current view of land cover/land use within Louisiana and to support NWRC's

work in evaluating Louisiana's coastal wetlands.

460 L3.2.3 2002 Louisiana Federal Emergency Management Agency (FEMA) LIDAR

The 2002 LIDAR was provided by the United States Army Corps of Engineers New Orleans

District. The following information is provided in the metadata of the LIDAR data set.

465 The horizontal coordinate system is projected coordinate system NAD 1983 UTM Zone 15N.

These data were produced for the Louisiana Federal Emergency Management Agency (FEMA)

Project under the U.S. Army Corps of Engineers, Saint Louis District contract number

DACW43-00D-0511 0014.

470 While the United States Army Corps of Engineers, St. Louis District (hereinafter referred to

USACE) has made a reasonable effort to insure the accuracy of the maps and associated data, it

should be explicitly noted that USACE makes no warranty, representation or guaranty, either

express or implied, as to the content, sequence, accuracy, timeliness or completeness of any of

the data provided herein. The USACE, its officers, agents, employees, or servants shall assume

475 no liability of any nature for any errors, omissions, or inaccuracies in the information provided

regardless of how caused. The USACE, its officers, agents, employees or servants shall assume

no liability for any decisions made or actions taken or not taken by the user of the maps and

associated data in reliance upon any information or data furnished here. By using these maps and

associated data the user does so entirely at their own risk and explicitly acknowledges that he/she

480 is aware of and agrees to be bound by this disclaimer and agrees not to present any claim or

demand of any nature against the USACE, its officers, agents, employees or servants in any

forum whatsoever for any damages of any nature whatsoever that may result from or may be

caused in any way by the use of the maps and associated data.

485 L3.3 Ground Topographic Surveys

No surveying was conducted during the feasibility stage of this project.

L4 GEOLOGY

490 The geologic development of coastal Louisiana is closely related to shifting Mississippi River

courses since the slowing of Holocene post-glacial sea level rise (Fisk, 1955; Frazier, 1967; and

Coleman and Gagliano, 1964). The Mississippi River has changed its course several times

during the last 7,000 years, leading to the development of the Mississippi River deltaic and

chenier plains. The deltaic plain is composed of several major delta complexes, two of which

495 (the Plaquemines/Modern and Atchafalaya) are still active. Dominant physiographic features of

the deltaic plain include abandoned courses and distributaries and their associated natural levees,

swamps, marsh, hundreds of lakes and bays, and barrier islands.

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Recognition that the deltaic plain is formed by an orderly progression of events related to

500 shifting Mississippi River courses led to the identification and characterization of the delta

cycle (Scruton, 1960; Frazier, 1967). The delta cycle is a dynamic and cyclic process that

alternates between periods of progradation and a subsequent transgression of deltaic headlands as

deltas are abandoned and reworked by marine waters (Penland et al., 1988; Roberts, 1997).

Throughout most of the last 7000 years the delta cycle has created more land by building

505 deltas (regressive phase) than was destroyed by relative sea level rise and erosional processes

(transgressive phase). Since the early 1900s man has had a major influence on many of the key

elements controlling the delta cycle. The Old River Control Structure has eliminated the delta

switching process by maintaining the Mississippi River in its present course. Flood protection

levees confine the flow of the Mississippi River eliminating overbank flooding and the nutrients

510 and sediments that accompany these floods. Also, the suspended sediment load of the

Mississippi River has declined by approximately 50 percent between the 1930 to 1952 period

and the 1963 to 1982 period (Kesel, 1988). This decline has been attributed to bank stabilization

by revetments, dams constructed on the Missouri River and other large tributaries, and other

erosion control measures.

515

As the natural delta-building process was restrained, relative sea level rise and erosion

(transgressive processes) began to dominate the coastal landscape. Within this environment of

diminished delta building, man began a period of extensive development in the coastal zone

beginning in the early 1900s. Man-made alterations to the natural landscape such as dredging of

520 navigation and access canals, construction of roads and levees within the wetlands, and drainage

projects altered the natural hydrology compounding the negative effects of relative sea level rise

and wetland erosion

Coastal Louisiana is characterized by depositional environments and shoreline configurations

525 representing various phases of the delta cycle. Presently, most of the Louisiana coastal zone is

in the marine-dominated, transgressive phase of the delta cycle. Only the Modern and

Atchafalaya Deltas are in the fluvially-dominated, regressive phase.

L4.1 Geologic Setting of Study Area

530

The study area is part of the Teche and Lafourche Delta complexes which began depositing

deltaic sediments in the study area approximately 4,500 years ago (Frazier, 1967). Bayou Black

was the main course of the Teche-Mississippi River which entered the study area from the west

approximately 4,500 years before present. Major distributaries of the Teche Delta which

535 contributed sediment to the study area were Bayous Penchant, Cocodrie, Piquant, Little Horn,

and Carencro. These distributaries all trend southeast, indicative of the direction of deltaic

growth. Bayou Lafourche was the main course of the Lafourche-Mississippi River which

entered the study area from the north approximately 2,000 years before present. Major

distributaries of the Lafourche Delta which contributed sediment to the study area were Bayous

540 Mauvais Bois, du Large, Grand Caillou, Terrebonne, Little Caillou, and Pointe au Chien.

Dominant physiographic features include the natural levees associated with Bayous Black and

Lafourche, Lakes such as Palourde, Mechant, de Cade, Boudreaux, and Felicity, the Isles

Dernieres and Timbalier barrier island chains, marshes, and bays.

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545 The entire study area is in the marine dominated/transgressive phase of the delta cycle. During

this phase, delta abandonment takes place and the processes of subsidence, erosion, and marine

transgression dominate the landscape. The result is land loss, submergence, habitat change

(driven mainly by elevation decrease and salinity increase), and an increase in water area.

550 The surface and shallow subsurface is generally characterized by natural levee, swamp, and

marsh deposits separated by abandoned distributaries. Natural levee deposits are generally

characterized by medium to stiff clays and silt. Swamp and marsh deposits consist mainly of

very soft clays and organic clays with peat. Natural levee, swamp, and marsh deposits are

generally less than 20 ft thick. Beach deposits composed mainly of fine sand and shell are found

555 along the Isles Dernieres and Timbalier Island chains. Interdistributary deposits are located

beneath natural levee, swamp and marsh deposits. Interdistributary deposits are commonly over

100 ft thick and consist of very soft to medium clays with minor amounts of silt, shell fragments,

and organics. Prodelta deposits, characterized by medium clays, may underlie interdistributary

deposits. Prodelta and interdistributary deposits vary widely in thickness throughout the study

560 area, but generally thicken from north to south. Massive substratum sands are located beneath

interdistributary and prodelta deposits.

L4.3 Groundwater

565 Groundwater is at or near the surface throughout most of the study area. Point bar deposits

associated with Bayou Black may be hydraulically connected to the adjacent waterway.

L5 GEOTECHNICAL INVESTIGATIONS AND DESIGN

L5.1 General

570 The project area is located in Terrebonne Parish, Louisiana. The following Table L5 presents the

features and the analyses performed.

Table L5  Geotechnical analysis performed

Feature Pile

Capacity

Slope

Stability

WS4 X X

EC3 X X

ES2 X

EC5 X X

CC3, CC4,

CC13, CS1

X

WW2 X

WD3 X

CD2 & 7 X

575

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The subsurface information available is for a general design and cost estimate purpose. The

subsequent geotechnical design on the detail features will be presented in a Design Report (DR)

in an appropriate time prior to the preparation of the Plans and Specifications.

580 L5.2 Field Investigation

Borings were obtained from existing exploration done in the area by the New Orleans District

(MVN). The borings used for this design were, CN99-3U, HNCL-32U, BLK-8U, 12-AIUT,

CNO7-2U. Boring logs will be presented in the appendix as Figure 1-5. They were chosen based

on the location relative to the different features and the fact that they were undisturbed samples.

585 These undisturbed samples were obtained by using a Shelby tube sampler.

While the borings are representative of subsurface conditions at their locations and specifically

for the reach along the length of the boring, variations in characteristics of the subsurface

materials are anticipated. Furthermore, many of the borings used, because of availability, are

590 dated and located some distance from the actual design feature. True design borings must be

done prior to any final design report at the actual location of the features in order to obtain a

more accurate representation of subsurface conditions.

Only two of the borings indicate a groundwater level of 5.2 ft GW conditions vary with rainfall

595 and drainage. Throughout the design a GW level of EL. 0 (NGVD) was assumed unless the

available data indicated differently.

L5.3 Laboratory Testing

The lab testing performed on the undisturbed samples includes Atterberg limits, unit weight,

600 unconfined compression tests and un-drained tri-axial shear tests. These results are presented in

the boring logs. Most of the borings are characterized by thicker layers of fat clays (CH) with

some silt and sandy silts. Logs are available in Figure L4 through Figure L8. The shear strength

parameters obtained from the borings and utilized in the analyses are summarized in the

following Table L6.

605

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Table L6 - Summary of Mechanical Properties for borings used

Boring Elevations

(top to

bottom)

Material Unit Weight

(pcf)

Cohesion

(psf)

Phi (deg)

HNCL-32U -5.4 to -35 CH 100 360 0

Figure L4 -35 to -45 CL 110 240 0

-45 to -57 CH 105 400 0

CN99-3U 7 to -10 CH 100 400 0

Figure L5 -10 to -25 SM 122 0 30

BLK-8U 2 to -20 CH 100 500 0

Figure L6 -20 to -35 CH 90 450 0

-35 to -55 CH 90 400 0

-55 to -73 CL 120 850 0

CNO7-2U 8.2 to 0 CH 110 500 0

Figure L7 0 to -15 CH 100 300 0

-15 to -20 ML 115 700 15

-20 to -60 CH 100 500 0

-60 to -90 CH 100 800 0

12-AIUT 1.86 to -15 CH 105 400 0

Figure L8 -15 to -31 ML 110 300 15

-31 to -105 CH 100 700 0

L5.4 Foundation Design

610 L5.4.1 Slope Stability Analyses (SS)

The results of the soil borings and laboratory test data were evaluated and the strength

parameters were selected for design. Some design parameters were also taken from typical

values presented in the USACE HSDRRS. Both, Q-case short term un-drained case and S-case

615 long term consolidated drained case analyses were performed.

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Table L7 - Typical Values for Silts, Sands and Rip Rap

Soil Type Unit Weight (pcf) Cohesion (psf) Friction Angle

(deg)

Silt 117 200 15

Silty Sand 122 0 30

Poorly graded sand 122 0 33

Riprap 132 0 40

S-case parameters

Silt: Cohesion = 0 psf, phi = 28

620 Clay: Cohesion = 0 psf, phi = 23

Stability of channel dredging and other earth cuts were analyzed using the GEO-Studio 2007

(Version7.14) software, specifically the SLOPE/W platform. The Spencer Method is used in this

analysis with a block specified slip surface to determine the critical slip surface and the factor of

625 safety (FS).

Factor of Safety Requirements for HSDRRS

Low Water (hurricane condition) 1.4

630 Low Water (non-hurricane condition) S-case 1.4

L5.4.2 Individual Features SS

-WD3: A cross section of existing channel conditions and expected dredging was provided.

635 Boring BLK-8U was used for the design. The channel is about 40 ft deep with slopes of 1 on 4

(1V: 4H). For the Q-case analyses FS of 1.7 and 1.7 were obtained for the left bank (Figure L9)

and the right bank, respectively. For the S-case FS of 2.1 and 1.9 were obtained for the left and

right bank respectively. These FS comply with the 1.4.

640 -WW2: The rock weir in this feature was analyzed using a simple Infinite Slope Analyses since

the granular material would yield infinite failures. The formula for the FS is:









tan

tan '

'

tan

tan '





F

H

c BAF

645 The second term can be eliminated because cohesion for rock is zero (0) and the parameter A of

the first term is associated with pore-pressure which can be assumed as 1 because the weir is

completely submerged. The angle phi corresponds to the friction angle and the angle beta

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corresponds to the angle of the slope. This calculation resulted in the determination that a 1 on 2

slope was necessary to achieve a 1.7 FS.

650

 -EC5: Boring CN99-3U was used for the analyses. The channel is 22 ft deep and 470 ft

wide. Analyses show that for Q-case and for S-case the slopes should be 1 on 4 in order

to achieve a FS higher than 1.4 (Figure L10). Shoreline erosion is expected in these

designs and mitigation methods shall be evaluated in a more detailed Design Report.

655

 CD2 & 7 (Figure L11): Boring HNCL-32U was used for the analysis. The features

consist of a channel 45 ft wide and about 10 ft deep. On both sides fill will be used to

create embankments. The one on the left bank will be a minimum of 6 ft tall and 10 ft

wide at the crown. The embankment on the right will be a minimum of 8 ft tall and 10 ft

660 wide crown. The analyses showed that for the smaller spoil bank the FS was on the order

of 2.0 with the toe of the embankment a minimum of 30 ft away from the channel bank.

The side with the larger embankment resulted in a FS of 1.6 with the toe of the

embankment a minimum of 40 ft away from the channel bank. The S-case analyses

results in a 1.6 FS for the smaller embankment and a 1.4 FS for the larger bank. These

665 results indicate that the embankments should have slopes of 1 on 3 and the channel banks

slopes of 1 on 2. If either of the embankments is to be larger than the minimum they

would have to be moved further away from the channel bank in order to maintain the

appropriate FS.

670  ES2: Boring CNO7-2U was used for this analysis. The use of 1 on 4 slope is

recommended to meet the Q-case and S-case FS. With a 1 on 4 slope the critical FS for

the S-case is calculated as 1.4 (Figure L12).

 EC3: For EC3 a global stability analysis was conducted with the water elevation at 6 ft At

675 this level the water is almost to the crown of the levee. For this analysis the FS was 5.0

(Figure L13).

L5.4.3 Bedding for Culverts

680 The culverts that do not require deep pile foundations will require bedding material. This

bedding should be 2 ft deep and should consist of 2a coarser gravel on the bottom with a finer

gravel on the top layer of the bedding.

L5.4.4 Pile Foundation

685

Most of the heavier structures will require deep pile foundation because of the quality of the soil

and the size of the feature. The pile founded features include: a pump station with obermeyer

gates (ES2), The ten 5 x 5 box culverts (EC3), the 15 x 15 sluice gate through the levee

section (WS4), the obermeyer gates across the channel with the highway bridge on top (EC5)

690 and the 10 x 10 culverts (CC3, CC4, CC13, CS1).

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Pile capacity analyses were conducted using the MVN Pile Capacity Program based on an Excel

macro. Borings used include: 12-AIUT and CNO7-2U. These results are presented in the

appendix. The pile capacity graph for WS4, EC3 and EC5 is noted as Figure L14 and Figure

695 L15. The pile capacity graph for ES2, CC3, CC4, CC13 and CS1 is noted as Figure L16 and

Figure L17.

Recommended FS for compression and tension design loads are:

700 Design Case With Pile Load Test Without Pile Load Test

Q-Case 2.0 3.0

S-Case 1.5 1.5

705

Note: Q-Case is characterized as a short term un-drained case relative to the soil.

S-Case is characterized as a long term consolidated drained case relative to the

710 soil.

L5.4.5 Construction Excavation

715 The excavations for construction will require a cofferdam system due to high GW levels as well

as the presence of waterways. The cellular cofferdam structures will be constructed from flat

sheet piles typical for such use to stabilize the adjacent ground and minimize groundwater

infiltration. The cofferdam system should be designed and analyzed according to all applicable

USACE design criteria.

720

a. Excavation will vary from elevation -7 NGVD for the obermeyer gates to -21 NGVD

for the pump station.

b. The design ground surface elevation varies from, depending on the feature, from 1.8 ft

725 to -5.4 ft.

L5.4.6 Hydrostatic Uplift

Hydrostatic uplift during construction should be controlled by using a passive dewatering system

730 with perforated pipe imbedded into trenches and then backfilled with gravel. Piezometric levels

in the pervious and semi-pervious foundation strata should be reduced to no higher than the

excavation surface. Adequate temporary piezometers shall be required to monitor the

performance of the dewatering system. Because dewatering and pressure relief operations will

lower the ground water level in the vicinity of the excavations and thus result in settlement of the

735 adjacent ground surface, measures such as cutoff walls, recharge wells, and/or some other

method may be necessary. A passive system was chosen based on the stratigraphy of the project

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area, composed largely of impervious clays. A well point active system would be highly

inefficient and costly because these systems are intended for more coarse grained pervious

material.

740

The dewatering system shall be implemented in all features that require the construction of pile

caps and in features built through levee sections. The trenches should be 3 ft deep 2 ft wide at the

bottom and 8 ft wide at the top. The trenches should be built around the outer edges of the

excavation and some trenches should also be built in the center of the excavation If they are large

745 enough.

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Figure L4 - Geotechnical Boring Data for Boring HNCL-32U (02-06)

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750

Figure L5 - Geotechnical Boring Data for Boring CN99-3U (99-527)

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Figure L6 - Geotechnical Boring Data for Boring BLK-8U (03-17885)

755

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Figure L7 - Geotechnical Boring Data for Boring CN07-2U (07-19678)

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Figure L8 - Geotechnical Boring Data for 12-AIUT (84-18) 760

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Figure L9 - WD3 Q-Case

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Figure L10 - EC5 Banks 765

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Figure L11 - S-Case

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770

Figure L12 - ES2 S-Case

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Figure L13 - EC3 Global Stability

775

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Figure L14 - Q-Case Pile Capacity

Figure 11

Q-Case Pile Capacity (WS4, EC3, EC5)

Boring 12-AIUT

-105-120

-15-30-45-60-75-90

0

15

0 10 20 30 40 50 60 70 80

Pile Capacity (Tons)

(ft) Elevation

Compresion w/o Load Test FS=3 Tension w/o Load Test FS=3Compresion w/ Load Test FS=2 Tension w/ Load Test FS=2

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Figure L15 - S-Case Pile Capacity

Figure 11

S-Case Pile Capacity (WS4, EC3, EC5)

Boring 12-AIUT

-105-120

-15-30-45-60-75-90

0

15

0 20 40 60 80 100 120 140

Pile Capacity (tons)

(ft) Elevation

Compresion w/o Load Test FS=1.5 Tension w/o Load Test FS=1.5Compresion w/ Load Test FS=1.5 Tension w/ Load Test FS=1.5

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780

Figure L16 - Q-Case Pile Capacity

Figure 12

Q-Case Pile Capacity (ES2, CC3, CC4, CC13, CS1)

Boring CNO7-2U

-105-120

-15-30-45-60-75-90

0

15

0 10 20 30 40 50 60 70 80 90

Pile Capacity (Tons)

(ft) Elevation

Compresion w/o Load Test FS=3 Tension w/o Load Test FS=3Compresion w/ Load Test FS=2 Tension w/ Load Test FS=2

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Figure L17 - S-Case Pile Capacity

Figure 12

S-Case Pile Capacity (ES2, CC3, CC4, CC13, CS1)

Boring CNO7-2U

-105-120

-15-30-45-60-75-90

0

15

-20 0 20 40 60 80 100 120 140 160

Pile Capacity (tons)

(ft) Elevation

Compresion w/o Load Test FS=1.5 Tension w/o Load Test FS=1.5Compresion w/ Load Test FS=1.5 Tension w/ Load Test FS=1.5

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785 L6 ENVIRONMENTAL ENGINEERING

L6.1 HAZARDOUS, TOXIC AND RADIOACTIVE WASTES

As reported in the Phase I ESA, during records research and site reconnaissance it was

determined that areas adjacent to some of the project features contained RECs that presented a

790 low to moderate risk of affecting potential project features, albeit that no RECs were noted

within direct proximity of land associated with any of the potential project features.

Should at anytime during the project HTRW concerns arise, the CEMVN would take immediate

actions to investigate the concerns. Should an HTRW issue be determined and the development

795 of a response action required, CEMVN would coordinate with the appropriate Federal and state

authorities to implement an approved response action.

For more information on the Phase I performed for the project see chapters four and five of the

main report along with the HTRW appendix, Appendix N.

800

L7 CIVIL DESIGN CRITERIA

L7.1 General

All drawing sheet references in this section can be found in Annex 4 of this Appendix.

805 L7.1.1 Surveys

Very little survey information was available for this feasibility design. When available, existing

ground elevations and bathymetry was used. If elevations were not available, reasonable

assumptions were made based on elevations from similar projects located in the same area.

L7.1.2 Right-of-Way (ROW)

810 Temporary and Permanent ROW areas were estimated based on the feature footprint and

construction limit requirements. A Real Estate plan showing actual Temporary and Permanent

ROW requirements will be performed at the beginning of the Construction P&S phase.

1) Temporary ROW / Construction Limits  Temporary right-of-way will be minimized to

reduce damage and mitigation to adjacent areas. Some features will require temporary

815 ROW outside of the feature footprint for construction equipment access and movement.

2) Permanent ROW  Some features such as the Structures will require long term

maintenance. Permanent ROW may be necessary for access to and around the feature.

See the Real Estate section for more information.

820 L7.2 Feature Designs

L7.2.1 STRUCTURES

1) Site Design  The various structures will require excavation and backfilling. See the

structural drawings for more details.

2) Construction  See the structural drawings for more details.

825 3) Assumptions - It is assumed that access to the sites is available or will be made available

through flotation channels.

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L7.2.3 SHORELINE PROTECTION

1) Site Design  Several locations require the Shoreline Protection feature. This project utilizes

830 Type B protection (see drawings sheet C-339) which consists of a rock berm placed parallel

to the existing bank. The top of the berm shall be 5 ft above the elevation of the existing

bank. The berm will be made of riprap material to resist wave action.

2) Construction  Construction of the Shoreline Protection will most likely take place from

floating vessels. The rock will be placed from adjacent barges with a track-hoe bucket, by

835 pushing the rock off the barge deck, or with a combination of both.

3) Assumptions  It is assumed that access to the sites is available or will be made available

through flotation channels.

L7.2.4 DREDGED CHANNELS

840 1) Site Design  Deepening of existing channels and widening of existing channels will be

performed in this project. See drawing C-339 for typical sections. Unless specifically

specified, an adjacent berm will be constructed to contain the dredge spoil.

2) Construction  The dredged channels will be constructed using one of the available dredge

types in the area (i.e., cutter head). For Type A Dredged Channels, the width of cut will be 5

845 ft or more away from the existing bankline to prevent sloughing of the bankline. The spoil

area will be constructed in a fashion to add value to the environment (i.e., marsh creation).

All exposed ground above the waterline will be seeded to prevent erosion.

3) Assumptions  Unless otherwise specified, it is assumed that all spoil material will be placed

in an adjacent spoil area that is constructed by building berms from in-situ material. If it is

850 determined that the dredge spoil can be used beneficially in other areas, the material will be

used for Marsh Creation areas and will be designed and constructed as described in

paragraph 7.2.12 (below).

L7.2.5 WEIRS

855 1) Site Design  Riprap type material will be placed across the channel approximately 10 ft

below the water surface. Side slopes will be 1 vertical to 5 horizontal as shown on drawing

C-339.

2) Construction  The riprap used to construct the weir will be placed with a track-hoe bucket

and will most likely be brought to the site via a barge or other floating vessel.

860 3) Assumptions  It is assumed that access to the sites is available or will be made available

through flotation channels.

L7.2.6 PLUGS

1) Site Design  Plugs will be constructed with a close-graded aggregate to an elevation 2 ft

865 above the water surface. The plug will be tied-in with 1V:4H slopes extending to the

existing ground. See drawing C-340 for a typical section.

2) Construction  The aggregate will be placed with a track-hoe bucket and will most likely be

brought to the site via a barge or other floating vessel.

3) Assumptions - It is assumed that access to the sites is available or will be made available

870 through flotation channels.

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L7.2.7 TERRACING

1) Site Design  Terracing consists of a series of 10 ft wide parallel berms positioned

approximately 90 degrees to the direction of surge. Existing terraced areas were looked at to

875 determine spacing, lengths, and relative areas. See drawing C-341 for details.

2) Construction  The terracing berms are constructed by excavating adjacent in-situ material

and piling the material until the berm is 2 ft above the water surface. The borrow trench is

located a minimum of 25 ft away to prevent sloughing. The exposed ground above the water

surface will be vegetated to reduce erosion.

880 3) Assumptions  It is assumed that access to the sites is available or will be made available

through flotation channels.

L7.2.8 CULVERTS

1) Site Design  The culvert is placed to convey water from one area to the other. Depending

885 upon the location, there may be multiple barrels and/or a flapgate.

2) Construction - The area to receive the culvert is excavated to 2 ft below the flowline. The

trench is filled with 2 ft of bedding material and backfilled around the pipe.

3) Assumptions - It is assumed that access to the sites is available or will be made available

through flotation channels.

890

L7.2.9 REMOVALS

1) Site Design  N/A

2) Construction  The structures will be removed with equipment such as a track-hoe with a

grapple, and the material will be removed off site and disposed at the contractors discretion.

895 3) Assumptions - It is assumed that access to the sites is available or will be made available

through flotation channels.

L7.2.10 SPOIL GAP

1) Site Design  Existing dredge spoil banks will be excavated to allow water conveyance.

900 Gaps will be excavated 50 ft long with 1V on 3H side slopes. See drawing C-342 for details.

2) Construction  The gaps will be excavated with track-hoes and sloped back to existing

ground. The excavated material will be either hauled off by the contractor or placed adjacent

to the gap. All exposed ground above the water surface will be seeded to reduce erosion.

3) Assumptions - It is assumed that access to the sites is available or will be made available

905 through flotation channels.

L7.2.11 MARSH BERM

1) Site Design  The marsh berm has a 30 ft wide top width. All exposed ground above the

water surface will be seeded for erosion protection.

910 2) Construction  The marsh berms will be constructed by borrowing adjacent in-situ material

at least 25 ft from the berm toe. The material will be piled until the berm is at an elevation of

+2.5.

3) Assumptions - It is assumed that access to the sites is available or will be made available

through flotation channels.

915

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L7.2.12 MARSH CREATION (BENEFICIAL USE OF DREDGE CHANNEL SPOIL)

1) Site Design  Marsh Creation areas consist of a containment berm surrounding the area to be

filled. The berm borrow site will be located within the marsh creation area. The fill material

borrow site will be located at some distance and location to be determined. Booster pumps

920 and effluent pipes will run between the dredge borrow site and the marsh creation areas.

2) Construction  A containment berm is first created around the area by excavating in-situ

material adjacent to the berm location. The material is piled until the berm is 2 ft above the

dredge fill elevation. Spill boxes will be placed in the berm to allow water to drain. The area

within the containment berms will be filled with dredge material up to an elevation of +2.5 to

925 +3.0 in one or two lifts. Grading stakes will be placed throughout the areas for monitoring

the fill elevations. The containment berm will require constant monitoring and maintenance

to ensure no dredge material is allowed to escape.

3) Assumptions  It is assumed from similar jobs that the construction fill elevation of the

dredged material will be +2.5 to +3.0 and will settle over several years to an elevation of

930 approximately +1.0 to +1.5. Once this elevation is achieved, marsh vegetation can either be

planted or establish naturally. The containment berms will be degraded to the adjacent

dredge fill elevation after settling.

L8 STRUCTURAL DESIGN CRITERIA

935

L8.1 FOUNDATION RECOMMENDATIONS

All drawings referenced in this section can be found in Annex 4 to this Appendix.

L8.1.1 GENERAL

940 Development of this proposed diversion project will require various proposed features to

accomplish the intended purpose. Among those will be a variety of structures. A description of

the foundations for each structural feature will be shown below. The pile founded structures will

incorporate the use of steel H-piles and sheet piles, precast prestressed concrete (PPC) piles, and

timber piles where indicated on the drawings. Preliminary assumptions of pile sizes, spacing, and

945 pile tip elevations were based on the design of similar structures found in the vicinity.

Verification of the pile assumptions, along with any adjustments, was accomplished with the use

of pile capacity curves that were developed for similar soils. A more accurate determination of

soil properties was not possible due to the absence of reliable borings, therefore pile tip

elevations may be adjusted in the next stage of design. All cast-in-place concrete structure

950 monoliths exposed to lateral loadings were analyzed using the COE CASE program CPGA

(X0080), Pile Group Analysis Program to determine adequacy of pile pattern assumptions.

Stability of sheet pile cellular structures was determined thru the use of the COE CASE program

CCELL (X0040), Analysis of Circular Sheet Pile Cells. Precast concrete box culverts will be

soil founded structures supported by a compacted base material of assumed varying thicknesses

955 which will be finalized in the next design stage. All designs were performed in accordance with

applicable COE and technical publications, and industry codes. All structures will be constructed

using conventional construction equipment and techniques. The contractor will be required to

provide dewatering systems (where necessary) in order to construct foundations in a near dry

atmosphere. The contractor will also be required to provide a system of shoring or open

960 excavation to safely facilitate construction procedures.

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L8.1.2 DESCRIPTION OF FEATURE FOUNDATIONS

a. Project Feature WS4.  The proposed concrete monolithic structures at this location will be

supported on a combination of steel HP14x73 piles, 12 in. x12 in. PPC piles, and 14 in. x14

965 in. PPC piles. Location, spacing, and pile tip elevations of the piling is shown on drawing S201. A 4 stabilization slab will be placed between the concrete substructures and the soil

foundation to act as a stable working surface during construction. A steel sheet pile seepage

cut-off wall will be placed around the perimeter of the concrete substructures. The pile tip

elevations of the cut-off walls are shown on drawing S-201.

970 b. Project Feature EC3.  The proposed cast-in-place concrete inlet and outlet monoliths of this

diversion structure will be supported on 14 in. x14 in. PPC piles. Location, spacing, and pile

tip elevations of the piling is shown on drawing S-210. A 4 in. stabilization slab will be

placed between the cast-in-place concrete substructures and the soil foundation. A steel sheet

pile scour wall will be placed around the perimeter of the inlet and outlet monoliths. The pile

975 tip elevation of the scour walls will be El.-30.0. The precast concrete box culverts located

between the inlet and outlet monoliths will be supported on a 2.0 ft thick base of compacted

material.

c. Project Feature ES2.  The proposed concrete pumping station, inlet, and outlet structures,

bridge and gate structures, and piers for the service access area at this location will be

980 supported on 14 in. x14 in. PPC piles. Location, spacing, and pile tip elevations of the piling

is shown on drawing S-330. A 4 in. stabilization slab will be placed between the concrete

substructures and the soil foundation. A steel sheet pile scour wall will be placed around the

perimeter of the concrete substructures. The pile tip elevation of the scour walls will be El.-

45.0.

985 d. Project Feature EC5.  The proposed concrete bridge substructure for this feature will be

supported on 14 in. x14 in. PPC piles. Location, spacing, and pile tip elevations of the piling

is shown on drawing S-140. A 4 in. stabilization slab will be placed between the concrete

substructure and the soil foundation. A steel sheet pile scour wall will be placed around the

perimeter of the concrete substructure. The pile tip elevation of the scour walls will be El.-

990 45.0.

e. Project Feature WW2.  The proposed steel sheet pile cells and connecting arcs forming a

straight line wall at this location will be founded at varying elevations, which are shown on

drawing S-220.

f. Project Feature CC14.  The substructure for this proposed feature will be a combination of

995 steel sheet piling and 12 in. diameter treated timber piles. Since reliable information

pertaining to the existing ground elevations is not available, pile tip elevations will be

determined in the next design stage.

g. Project Feature CC3, CC4, CC13, and CS1.  The proposed cast-in-place concrete inlet and

outlet monoliths of this diversion structure will be supported on 14 in. x14 in. PPC piles.

1000 Location of the piling is shown on drawings R-301 and R-302. Lateral spacing of the piles

will be 6.0 ft on center, and the pile tips will be located at El.-28.0. A 4 in. stabilization slab

will be placed between the cast-in-place concrete substructures and the soil foundation. A

steel sheet pile scour wall will be placed around the perimeter of the inlet and outlet

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monoliths. The pile tip elevation of the scour walls will be El.-30.0. The precast concrete box

1005 culverts located between the inlet and outlet monoliths will be supported on a 3.0 ft thick

base of compacted material. The steel sheet pile wingwalls connected to the inlet and outlet

monoliths will extend from a top elevation of +4.0 to a tip elevation of -30.0.

h. Project Feature CC15.  The substructure for this proposed feature will be a combination of

treated timber piles and treated 2 in. x12 in. timber sheeting. Pile tip elevations could not be

1010 determined at this time due to the lack of reliable existing ground elevations.

L8.2 STRUCTURAL DESIGN FOR DIVERSION FACILITY

L8.2.1 GENERAL

1015 The general physical configuration of structures for this proposed diversion project were based

on a variety of considerations, among them hydraulic requirements, similar structures performing

the same function, and utilizing existing designs from other projects. Two types of box culverts

are being presented in this project. The first type constructed of reinforced cast-in-place concrete,

and the other reinforced precast concrete. All other concrete structures will be reinforced and

1020 cast-in-place, except the bridge beams for the highway, and trash handling bridges which will be

PPC beams. Concrete member sizes were assumed based on similar structures of equivalent size

with similar loadings, therefore, no stress analyses were performed in this design phase.

L8.2.2 DESCRIPTION OF STRUCTURAL FEATURES

1025 a. Project Feature WS4.  The proposed structures at this location will be a series of reinforced

cast-in-place concrete box culverts constructed monolithically in conjunction with inflow,

roller gate, bulkhead, and outflow monoliths. These structures will be located under an

existing earth levee. There will be six box culvert barrels, each 15 ft high and 15 ft wide

(inside dimensions). The flow line elevation inside the barrels will be El.-15.0. The box

1030 culverts base slab will be 4.0 ft thick, the top slab will be 3.0 ft thick, the interior vertical

walls will be 2.5 ft thick, and the exterior vertical walls will be 3.0 ft thick. The length of the

box culverts will be 120.0 ft. The concrete inflow monoliths on the upstream end of the

structure will be comprised of a 4.0 ft thick base slab and two 3.0 ft thick vertical guidewalls

providing a length of 90.0 ft. The roller gate monolith will be 60.0 ft long and 108.5 ft wide.

1035 The concrete bulkhead and outflow monoliths on the downstream end of the structure will

also be comprised of a 4.0 ft thick base slab and two 3.0 ft thick vertical guidewalls

providing a length of 95.0 ft and a width of 108.5 ft. The inflow channel bottom will be El.-

15.0, with a width of 108.5 ft and side slopes of 1 vert. on 3 horiz. The total width of the

concrete structure will be 108.5 ft. The outflow channel bottom will be El.-19.0, with a

1040 width of 108.5 ft and side slopes of 1 vert. on 3 horz. Vertical slots and structural steel roller

guides will be provided in the concrete walls at each end of the barrels for the placement of a

bulkhead, when required. A 15 ft high and 15 ft wide fabricated structural steel roller gate

will be located at the upstream end of each barrel. A concrete platform will be located at

El.+21.0 to support the roller gate operators. A machinery building will be located adjacent

1045 to the support platform, also at El.+21.0. A 2.0 ft thick vertical concrete seepage cut-off wall

extending from the top of the box culverts to El.+17.0 will be located on the roller gate

monolith near the centerline of the earth levee. A 17.0 ft wide and 34.0 ft long timber pile

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supported concrete bulkhead storage slab will be located on the landside of the levee. This

feature can be seen in drawings S-101 and S-201 located in Annex 4 to this Appendix.

1050 b. Project Feature EC3.  The proposed structures at this location will be a series of precast

reinforced concrete box culverts placed individually, with a common cast-in-place reinforced

concrete inflow monolith located at each end of the culverts. This structure will be located

under an existing earth levee. There will be ten box culverts placed parallel to each other, and

spaced at 10.0 ft on center. Each culvert will be 5 ft high and 5 ft wide (inside dimensions).

1055 The flow line elevation inside each culvert will be El.-5.0. The flow line elevation inside

each culvert will be El.-5.0. The thickness of the base slab, top slab, and side walls will be

determined during detailed design using the applicable requirements of ASTM C 1433 and

this design will be confirmed with a precast fabricator. The approximate length of the

culverts will be 48.0 ft. The concrete inflow monoliths will be comprised of a 1.5 ft thick

1060 base slab, with 1.5 ft thick vertical divider walls located on each side of the culverts. A steel

sheet pile wingwall will be connected to the vertical walls at each end of the monolith to

retain the embankment. The inflow monolith adjacent to the Grand Bayou will be 15.0 ft

long and 101.5 ft wide, and the inflow monolith at the other end of the culverts will be 13.0 ft

long and 101.5 ft wide. A 1.5 ft thick vertical headwall will be located at each end of the

1065 culverts. The channel bottom at the Grand Bayou end of the structure will be El.-5.5, and the

channel bottom at the other end will be El.-5.0. The channel bottom width at both ends will

be 111.5 ft with side slopes of 1 vert. on 3 horiz. Slots will be provided in the divider walls at

each end of the structure for the placement of stoplog needles, when required. A 5 ft high and

5 ft wide flap valve will be attached to the Grand Bayou end of each culvert. Since operation

1070 of this structure considers flows in both directions, provisions will be made to retain the flap

valves in a full open position. Slots will also be provided in the divider walls at the structure

end opposite the Grand Bayou for the placement of an adjustable weir. A 10.0 ft wide and

10.0 ft long timber pile supported concrete dewatering needles storage slab will be located on

the Grand Bayou side of the levee. This feature can be seen in drawings S-110 and S-210

1075 located in Annex 4 to this Appendix.

c. Project Feature ES2.  This proposed feature will be a combination of multiple structures. A

proposed channel thru this location will provide a channel bottom width of 470.0 ft with an

elevation of El.-14.0. Side slopes of the channel will be 1 vert. on 4 horiz. A new highway

bridge will be constructed to span the channel. A stormwater pumping station will be

1080 constructed adjacent to the bridge, and located on the centerline of the channel. A series of

pneumatic spillway gates will be constructed in conjunction with the bridge substructure on

each side of the pumping station. This feature can be seen in drawings S-130, S-230, and S330 located in Annex 4 to this Appendix.

1) Pumping Station  The proposed pumping station will be located on the upstream side of

1085 the highway bridge. This structure will be made up of the following four parts; the

structure containing the pumps, the inlet structure containing the trash racks and trash

handling bridge, the outlet structure which will also be the highway bridge footing, and

the service access and parking area. The cast-in-place reinforced concrete pump structure

will be 93.0 ft long and 160.0 ft wide. The flow line elevation of the pump intake ports

1090 will be El.-14.0, and the flow line elevation of the discharge outlets will be El.-12.5. The

founding elevation of the pump structure will be El.-21.0. Sluice gates and gate operators

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will be provided for the intake ports at the upstream end of the structure, and for the

discharge outlets at the downstream end. Two 9 ft high and 15 ft wide access tunnels will

be located in the substructure, extending the width of the structure. The floor elevation of

1095 the upper tunnel will be El.+9.0, and the floor elevation of the lower tunnel will be El.-

2.0. The operating floor elevation will be El.+23.0. An 80.0 ft wide rigid frame steel

building, extending the width of the pump structure, will be provided. The building will

extend vertically from the operating floor to El.+60.0. A bridge crane will be located

inside the building and will be sized during a later design phase based on the weight of

1100 the pump and prime mover. A 6 ft wide walkway at El.+29.0 will be located on the

downstream side of the building, and extend the width of the pump structure. The cast-inplace reinforced concrete inlet structure containing the structural steel trash racks will be

55.0 ft long and 160.0 ft wide. The flow line elevation of the inlet structure will be El.-

14.0, and the founding elevation will be El.-21.0. A trash raking machine will be utilized

1105 to remove trash from the trash racks. A 26.0 ft wide vehicle bridge at El.+15.0, extending

the width of the inlet structure, will be located adjacent to the trash racks to provide

access for trash removal. The bridge will be comprised of a reinforced concrete deck

supported by 5-27 in. PPC beams spaced at 5.5 ft on center. Slots will be provided in the

upstream end of the 4.0 ft thick vertical divider walls located on the inlet structure for the

1110 placement of stop logs, when required. The cast-in-place reinforced concrete outlet

structure, which also serves as the footing for the proposed highway bridge piers, will be

40.0 ft long and extend the width of the pump structure. The flow line elevation of the

outlet structure will be El.-14.0, and the founding elevation will be El.-18.0. The service

access and parking area, located adjacent to the East end of the pump structure, will be

1115 40.0 ft wide and approximately 124.0 ft long. The area will be a reinforced concrete deck

at El.+15.0 supported by 36 in. PPC beams spaced at 7.0 ft on center. The beams will be

supported at the pump structure on concrete haunches. The other end of the PPC beams

will be supported on a continuous cast-in-place reinforced concrete beam which will be

supported on 2.5 ft diameter concrete columns spaced at 20.0 ft on center. The columns

1120 will be resting on 10.0 ft square concrete footings. The footings will be 4.0 ft thick and

founded at El.-21.0.

2) Highway Bridge  The centerline of the proposed highway bridge will be located

approximately 20.0 ft downstream from and parallel to the pumping station. The bridge

will span the proposed 470.0 ft wide channel. The roadway width will be 32.0 ft,

1125 assuming two 12.0 ft wide driving lanes and two 4.0 ft wide shoulders. A concrete barrier

wall and aluminum single tube guardrail will be placed on each side of the roadway. The

roadway deck will be cast-in-place reinforced concrete with a top El.15.0. The

approximate length of the bridge deck between the end abutments will be 552.0 ft. The

bridge deck will be supported with 5-36 in. PPC beams spaced at 7.0 ft on center. The

1130 end abutments will be cast-in-place reinforced concrete with turned back wings, and

supported with a 3.0 ft thick foundation wall. The wall will rest on a 4.0 ft thick common

footing which will also support the intermediate piers and spillway gates. The 3.0 ft thick

intermediate piers will be 40.0 ft long and extend from a top elevation of approx. El.11.0

to the common footing, which will be founded at El.-18.0. The span lengths between

1135 piers are shown on drawing S-130.

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3) Pneumatic Spillway Gates  The proposed spillway gates will be located within the

confines of the first two highway bridge spans on each side of the pumping station.

Design and operation of the gates will be similar to those produced by Obermeyer Hydro,

Inc. The 10 ft wide gates are raised and lowered by means of air bladders, controlled with

1140 compressed air. The 83.0 ft bridge spans will contain eight gates, and the 63.0 ft bridge

spans will contain six. The gates will be hinged at the bottom to a common 4.0 ft thick

concrete foundation, 40.0 ft wide and the length of the highway bridge. The hinge point

will be approx. El.-14.0, and the top of the gate will terminate at El.+6.0. The air bladders

provided will be in 20.0 ft lengths. Restraining straps will be used to ensure the gates stay

1145 within their intended operating range. UHMW polyethylene abutment plates are attached

to the bridge piers to provide a rubbing surface and seal for the gates as recommended by

the gate manufacturer. The first bridge spans adjacent to the abutments will utilize a 2.0 ft

thick concrete wall oriented parallel to the bridge, in lieu of the spillway gates. The top of

the walls will be at El.+6.0 and rest on the common foundation at El.-14.0.

1150 d. Project Feature EC5.  This proposed feature will be a combination of two structures. A

proposed channel thru this location will provide a channel bottom width of 470.0 ft with an

elevation of El.-14.0. Side slopes of the channel will be 1 vert. on 4 horiz. A new highway

bridge will be constructed to span the channel, and a series of pneumatic spillway gates will

be constructed in conjunction with the bridge substructure. This feature can be seen in

1155 drawings S-140 and S-240 located in Annex 4 to this Appendix.

1) Highway Bridge  The centerline of the proposed highway bridge will be oriented normal

to the centerline of the proposed channel, and span the overall width of the channel. The

roadway width will be 32.0 ft, assuming two 12.0 ft wide driving lanes and two 4.0 ft

wide shoulders. A concrete barrier wall and aluminum single tube guardrail will be

1160 placed on each side of the roadway. The roadway deck will be cast-in-place reinforced

concrete with a top El.15.0. The approx. length of the bridge deck between the end

abutments will be 552.0 ft. The bridge deck will be supported with 5-36 in. PPC beams

spaced at 7.0 ft on center. The end abutments will be cast-in-place reinforced concrete

with turned back wings, and supported with a 3.0 ft thick foundation wall. The wall will

1165 rest on a 4.0 ft thick common footing which will also support the intermediate piers and

spillway gates. The 3.0 ft thick intermediate piers will be 40.0 ft long and extend from a

top elevation of approx. El.11.0 to the common footing, which will be founded at El.-

18.0. The span lengths between piers are shown on drawing S-140

2) Pneumatic Spillway Gates  The proposed spillway gates will be located within the

1170 confines of all five 83.0 ft bridge spans. Design and operation of the gates will be similar

to those produced by Obermeyer Hydro, Inc. The 10 ft wide gates are raised and lowered

by means of air bladders, controlled with compressed air. Each 83.0 ft bridge span will

contain eight gates. The gates will be hinged at the bottom to a common 4.0 ft thick

concrete foundation, 40.0 ft wide and the length of the highway bridge. The hinge point

1175 will be approx. El.-14.0, and the top of the gate will terminate at El.6.0. The air bladders

provided will be in 20,0 ft lengths. Restraining straps will be used to ensure the gates

remain within their intended operating range. UHMW polyethylene abutment plates are

attached to the bridge piers to provide a rubbing surface and seal for the gates. The first

bridge spans adjacent to the abutments will utilize a 2.0 ft thick concrete wall oriented

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1180 parallel to the bridge, in lieu of the spillway gates. The top of the walls will be at El.+6.0

and rest on the common foundation at El.-14.0.

e. Project Feature WW2.  The proposed structure at this location will be a water control

structure oriented normal to the centerline of the existing waterway. The structure will

require the placement of twenty circular steel sheet pile cells and eighteen steel sheet pile

1185 connecting arc cells, and the placement of a rock weir. Construction of this feature will

provide a straight line structure with a 100.0 ft opening in the sheet pile cell wall. The

opening will allow the passage of watercraft. A rock weir will be placed in the opening with

a top elevation of El.-12.0, and side slopes of 1 vert. on 2 horiz.. The circular cells will have

a diameter of 37.5 ft spaced at 42.5 ft on center, and a top elevation of El.+3.0. The

1190 connecting arc cells will have a radius of approx.11.0 ft and a top elevation of El.+3.0. Total

length of the proposed structure will be 940.0 ft. Design of the circular and connecting arc

cells was based on the assumption that PS27.5 sheet piles will be used. Determination of

factors of safety of the cell failure modes were calculated with the use of the COE CASE

program CCELL (X0040). All circular and connecting arc cells will be filled with sand or

1195 shells. This feature can be seen in drawing S-220 located in Annex 4 to this Appendix.

f. Project Feature CC14.  The proposed structure at this location will also be a water

control structure oriented normal to the centerline of the existing waterway. A straight line

wall will be constructed in the waterway with the use of 12 in. diameter treated timber piling,

and steel sheet piling. The timber piling will be spaced at 5.0 ft on center, and provide a

1200 cluster of piles at each location. The cluster will have one vertical pile, and two battered

away from the wall. 20.0 ft long sheet pile will be placed between the vertical timber piles. A

4.0 ft wide timber walkway will be located on top of the battered piles and extend the total

length of the structure. Three fabricated structural steel boxlike enclosures will be attached at

the center of the structure. A 4.0 ft square flap valve will be attached to each enclosure on the

1205 same side. An adjustable weir will be attached to each enclosure on the opposite side. Timber

stoplogs will be used to adjust the water level at the weir. The top elevation and total length

of the proposed structure will be determined in the next design phase, since reliable

topography information was not available at this time. This feature can be seen in drawing S220 located in Annex 4 to this Appendix.

1210 g. Project Features CC3, CC4, CC13, and CS1.  The proposed structures at these locations will

be a series of precast reinforced concrete box culverts placed individually, with a common

cast-in-place reinforced concrete inflow monolith on the upstream end of the culverts and a

common cast-in-place reinforced concrete outflow monolith on the downstream end of the

culverts. These structures will be located under existing roadways. There will be six culverts

1215 placed parallel to each other, and spaced at 14.0 ft on center. Each culvert will be 10 ft high

and 10 ft wide (inside dimensions). The flow line elevation inside each culvert will be El.-

10.0. The thickness of the base slab, top slab, and side walls will be determined at a later time

when a specific fabricator for the precast culverts is considered. The approx. length of the

culverts will be 100.0 ft. The concrete inflow monoliths will be comprised of a 2.5 ft thick

1220 base slab with 3.0 ft thick vertical divider walls located on each side of the culverts. A steel

sheet pile wingwall will be connected to the vertical walls at each end of the monoliths to

retain the embankment. The inflow monoliths will be 53.0 ft long, and the outflow monoliths

will be 22.0 ft long. A 1.5 ft thick vertical headwall will be located at each end of the

1181
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culverts. The flow line elevation of the inflow and outflow monoliths will be El.-10.0. The

1225 channel bottom at each end of the structures will be El.-10.0. Slots will be provided in the

divider walls at each end of the inflow and outflow structures for the placement of stoplog

needles, when required. Galvanized structural steel trash racks will be placed between the

divider walls of the inflow monoliths for all four structures. Trash handling access bridges

will be constructed adjacent to the trash racks. The bridges which will be constructed with

1230 precast concrete deck slabs, will allow for a 15.0 ft wide vehicle clearance. A 4 ft wide

galvanized steel walkway and vehicle guardrail will be erected parallel and adjacent to the

bridges. A 10 ft square sluice gate and gate operator will be installed on a concrete headwall

at the inlet end of all culverts. Reinforced concrete platforms will be constructed at the inlet

end of all culverts to support the sluice gate operators. The top of the platforms will be

1235 El.+13.5. A 15.0 ft wide and 10.0 ft long timber pile supported concrete slab for dewatering

needles storage will be located near the inflow end of all four structures. The handling of

traffic during construction has not been addressed at this time, therefore it has not been

determined whether a temporary road relocation will be necessary at each or any of the four

structure locations. These features can be seen in drawings R101, R301 and R302 located in

1240 Annex 4 to this Appendix.

h. Project Feature CC15.  The proposed structure at this location will be a water control

structure oriented normal to the centerline of the existing waterway. A straight line wall with

three openings (boat bays) will be constructed in the waterway with the use of 12 in.

diameter treated timber piling, and 2 in. x12 in. treated timber sheeting. The timber piling

1245 will be spaced at 8.0 ft on center, and provide a pair of piles at each location. The pair will be

one vertical, and one battered away from the wall. The vertical piling will be 40.0 ft long,

and the battered piling will be 45.0 ft long. Two layers of 2 in x12 in sheeting will be placed

vertically and parallel to the vertical piling, for the entire length of the proposed structure.

The piling and sheeting will be separated with 10 in x 10 in treated timber wales attached

1250 horizontally. The three boat bay openings will be centered on the waterway, and will allow

the passage of watercraft. The clear openings of the boat bays will be 7.0 ft horizontal, and

approx. 5.0 ft vertically. The top elevation and total length of the proposed structure will be

determined in the next design phase, since reliable topography information was not available

at this time.

1255

L9 ELECTRICAL AND MECHANICAL REQUIREMENTS

L9.1.1 ELECTRICAL SOURCES AND SUPPLY REQUIREMENTS

GENERAL

1260 Development of this proposed diversion project will require various proposed structural features

to accomplish the intended purpose. Specific structural features will require an electrical power

source depending on the operational requirements at each site. The ability to furnish electrical

power to each structural feature from an offsite location has not been determined at this time, and

will be investigated in another design stage. The possible electrical requirements at each feature

1265 site have been presented below.

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L-54

L9.1.2 ELECTRICAL REQUIREMENTS PER SITE

a. Project Feature WS4.  An electrical power supply will be required to operate the roller gate

operators. Whether the operators will be electrically or hydraulically operated has not been

1270 determined at this time. In either case an electrical power source will be required for the

operator motors, or for the electrical motors driving the hydraulic pumps for the operators. In

addition, a power source will be required for the machinery building lighting, and

switchboard equipment in the building.

b. Project Feature ES2.  An electrical power supply will be required to operate the intake, and

1275 discharge sluice gate operators located inside the pumping station. Whether the operators will

be electrically or hydraulically operated has not been determined at this time. In either case

an electrical power source will be required for the operator motors, or for the electrical

motors driving the hydraulic pumps for the operators. In addition, a power source will be

required to operate the trash raking machine located on the inlet structure for the pumping

1280 station. An electrical power source will also be required inside the building located on top of

the pumping station for the lighting, exhaust fans, and bridge crane. The air compressor and

electrical control panel for the pneumatic spillway gates may be located inside the pumping

station building, and if that is the case a permanent electrical power source will be required.

Otherwise, a portable air compressor could be utilized.

1285 c. Project Feature EC5.  The electrical control panel and air lines termination point for the

pneumatic spillway gates will be located near one of the highway bridge abutments. It has

been assumed a portable air compressor will be used to activate the spillway gates, and

therefore an offsite electrical power supply will not be required.

d. Project Features CC3, CC4, CC13, and CS1.  An electrical power supply will be required to

1290 operate the sluice gate operators. Whether the operators will be electrically or hydraulically

operated has not been determined at this time. In either case an electrical power source will

be required for the operator motors, or for the electrical motors driving the hydraulic pumps

for the operators. In addition, a power source will be required for the control house building,

lighting and switchboard equipment.

1295 e. Electric Power Source(s).  Electric power source(s) can be either commercial utility electric

power or diesel engine generators. Location of commercial utility power and the cost to

supply this power will be compared to the cost of a diesel engine generator set, including

estimated O&M costs to determine the recommended source of the required electrical power.

1300 L9.2 SOLAR POWER SUPPLY SYSTEMS

L9.2.1 GENERAL

At this phase of the design it has been determined no structural features will incorporate a solar

power supply system.

1305 L9.3 ELECTRICAL AND MECHANICAL DESIGN FOR DIVERSION FACILITY

L9.3.1 GENERAL

The size and type of electrical and mechanical components for the project features were selected

based on a variety of considerations, among them hydraulic requirements, similar features

performing the same function, and utilizing existing designs from other projects.

1310

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L9.3.2 ELECTRICAL/MECHANICAL REQUIREMENTS PER SITE

a. Project Feature WS4.  Regulation of flow thru the culverts will be controlled with the use of

six 15x15 fabricated structural steel roller gates. The gates will be raised/lowered with the

use of a gate hoist supplied by a known and acceptable gate manufacturer. Selection of either

1315 electric motor operated or hydraulically operated gate hoists will be determined in a later

project design stage. Two fabricated structural steel bulkheads approximately 15 ft square

will be provided and stored on site when not in use. The bulkheads will be fitted with rollers,

and vertical steel roller guides will be cast in slots in the concrete walls.

b. Project Feature ES2.  Regulation of flow in the proposed channel at this site will be

1320 controlled with the combined use of a stormwater pumping station, and pneumatic spillway

gates.

1) Pumping Station - The pump station will utilize ten 9 wide by 8 high cast iron sluice

gates at the intake end, and five 10x10 cast iron sluice gates at the discharge end of the

structure. The gates will be raised/lowered with the use of a gate hoist supplied by the

1325 sluice gate manufacturer. The gates will be mounted to a cast iron wall thimble cast in the

concrete. The gates located at the intake end of the structure will be positioned to provide

a flush bottom closure, and the gates located at the discharge end will be positioned to

provide a raised bottom closure. Selection of either electric motor operated or

hydraulically operated gate hoists will be determined in a later project design stage. The

1330 pumping station will be provided with five vertical lineshaft stormwater pumps. Each

pump will provide a rated capacity of 800 cubic ft per second. Each pump will be driven

with an individual diesel engine thru a right angle speed reducer. The diesel engine

exhaust system will extend outside the steel building enclosure. In addition, exhaust fans

will be provided in the building. A rail mounted bridge crane with a movable trolley will

1335 also be provided inside the building. The lifting capacity of the bridge crane will be

determined at a later time when requirements are known. A mechanical trash rake will be

provided at the concrete intake structure to remove trash and debris from trash racks. The

mechanical rake will be on a movable trolley extending the width of the trash racks.

2) Pneumatic Spillway Gates  Operation of the gates requires a compressed air source.

1340 Distribution of the compressed air to the gate bladders will be attained thru stainless steel

pneumatic pipes embedded in the concrete structure supporting them. All the pipes will

terminate at one central location where the compressed air source is introduced, which

will be either a portable or permanently installed air compressor. Location of the air

compressor will be finalized at a later time.

1345 c. Project Feature EC5.  Regulation of flow in the proposed channel at this site will be

controlled with pneumatic spillway gates. Operation of the gates requires a compressed air

source. Distribution of the compressed air to the gate bladders will be attained thru stainless

steel pneumatic pipes embedded in the concrete structure supporting them. All the pipes will

terminate at one central location where the compressed air source is introduced, which will

1350 be either a portable or permanently installed air compressor. Location of the air compressor

will be finalized at a later time.

d. Project Features CC3, CC4, CC13, and CS1.  Regulation of flow thru the culverts at each of

these sites will be controlled with the use of six 10x10 cast iron sluice gates. The gates will

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L-56

be raised/lowered with the use of a gate hoist supplied by the sluice gate manufacturer. The

1355 gates will be mounted to a cast iron wall thimble cast in the concrete, and positioned to

provide a flush bottom closure. Selection of either electric motor operated or hydraulically

operated gate hoists will be determined in a later project design stage.

L10 OPERATIONS AND MAINTENANCE

1360 All features were considered for Operational Cost and Maintenance Cost. Items that require

painting, periodic inspections and debris removal were considered features that will have annual

cost to them and have been priced accordingly. Features that consist of dredging or berm type

work are considered as having no maintenance cost.

1365 Operation of the HNC lock and sector gate will involve closure of the sector gate year round.

Normal vessel traffic will pass through the lock. A few times each year, large vessels that will

not fit in the lock will need to pass through the structure. These vessels will schedule openings

of the sector gate portion of the structure. After the vessel passes, the sector gates will again be

closed. The sluice gates located within the HNC lock structure will be open year round with the

1370 exception of storm event conditions.

For the purposes of benefits analysis, all structures, with the exception of the HNC Lock, were

assumed to be in the open position year-round.

1375 L11 COST ESTIMATES

L11.1 Basis of Cost Estimate

Two types of estimates were developed for this study, a preliminary cost estimate and a detailed

cost estimate. The preliminary cost estimate for this Feasibility Study is based upon unit price

method. The detailed cost estimate has been developed for all features identified in each of the

1380 study alternatives. Most of the construction quantities and estimates, for both type of estimates,

were based upon historical costing data for this area and have been developed using the most

recent and accurate information available. This data was developed specifically for this area and

for this type of construction practice. The unit price cost estimates have been developed for all

features identified in each study alternative. The detailed cost estimate is based upon developed

1385 crews of equipment and labor for only new type construction for the base year of 2010. The unit

price estimates are based on the current design concepts, data and quantities for each study

alternative, and site information available to date. Unit pricing for both types of estimates, come

from data that was developed from using the most recent cost information for similar type

construction.

1390

L11.1.1 Equipment Cost

The equipment cost, used in the detailed estimate to perform this work is specific for this area

and for this type of construction practice

1395 L11.1.2 Labor Cost

The labor rates used in the detailed estimate to perform this work are specific for this type of

construction and specifically for the State of Louisiana.

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L-57

L11.1.3 Dredge Cost

1400 All dredging cost used in this study were developed from previous information and data, from

previous dredging contracts from this area. Costs for the preliminary type estimate were

developed from unit price method from previous dredging contracts. Costs for the detailed

estimates were developed by the CEDEP calculation method.

1405 L11.1.4 Estimate Documents

The preliminary cost estimates for the various components were developed from conceptual

exhibits, schematics, sketches and in limited cases, from drawings for the components. Many of

the exhibits were GIS-based and should be considered less accurate than detailed construction

plans.

1410

L11.1.5 Areas of Consideration for Cost

The estimate includes considerations for the following factors:

Permanent constructed facility

Ancillary site improvements, such as driveway, drainage, fencing, security, lighting, etc.

1415 Existing Site Conditions

Construction Access

Construction Techniques

Major construction facilities

Temporary Road Relocations and detours

1420 Temporary railroad Relocations

Pipeline Relocations

Utility Adjustments and Relocations

Construction Sequences

Storm Water pollution

1425 Dewatering and water management

Net Earth Quantities

Availability of Material

1430 L11.2 Contingencies

Contingencies of 39% were used for all features identified in each study alternative for the

preliminary cost estimates. These estimates were used for alternatives comparison.

Contingencies for the MCACES detailed estimate are based on a Cost and Schedule Risk

1435 Analysis completed using Crystal Ball software. This analysis resulted in a 34% contingency,

which was used for the MCACES detailed estimate performed on the RP. Further discussion of

the Cost and Schedule Risk Analysis are discussed in the Risk Analysis Section below.

L11.3 Planning, Engineering and Design

1440 A rate of 10 percent was applied for all features identified in each study alternative that

contained construction type activity. This percentage is based on MVNs average cost for

planning, engineering and design for a Feasibility Report.

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L11.4 Construction Management

1445 A rate of 8 percent applied to all features identified in each study alternative that contained

construction type activity. This percentage is based on MVNs average expenditures for

construction management on a typical contract of this magnitude.

L11.5 Detailed Estimate

1450 A detailed cost estimate was performed on the Recommended Plan (RP). The detailed cost was

developed using MCACES program as required under MVD direction. Included in the estimate

is the category for Lands and Damages, Cultural Resource Preservation, Planning,

Engineering and Design and Construction Management. All construction type work is divided

in the Relocations, Roads, Railroads and Bridges, Channels and Canals, Floodway Control &

1455 Diversion Structures and Bank Stabilization. This estimate can be seen in Volume III Appendix

O.

L11.6 Risk Analysis

A cost risk analysis was performed for this project in accordance with ER 1110-2-1302

1460 paragraph 7.3.2 and ER 1110-2-1302, Appendix P, paragraph 4. The results of the cost risk

analysis are shown in the Project Cost and Schedule Risk Analysis Report included in Volume

III Appendix P.

L12 CONSTRUCTION SEQUENCE

1465 L12.1 General

The anticipated construction schedule for the RP is shown in Figure L18 and Figure L19. This

schedule assumes a two year preconstruction engineering and design period and a five year

construction period. Dates on the schedule are for demonstration purposes and do not represent

actual planned dates. The schedule assumes that various types of work will be performed

1470 concurrently. This schedule may be shortened by adding crews for more concurrent

construction.

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Figure L18 - Construction Schedule

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1475

Figure L19 - Construction Schedule (Page 2)

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L13 ANNEXES

1480 Annexes are provided as separate document.

Annex 1  Detailed Construction Cost Estimates for Studied Alternatives

Annex 2  Detailed Hydraulic Modeling Studies

Annex 3  Hydraulic Model Sensitivity Analysis Report

1485 Annex 4  Engineering Drawings

Annex 5  Total Project Cost Summary

Annex 6  Reserved

Annex 7  Reserved

Annex 8  Reserved

1490

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Volume III

APPENDIX L

Annex 2



Convey Atchafalaya River to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

Final Feasibility Report

 Appendix L  Engineering Investigations and Cost Estimates

Annex 2  Detailed Hydraulic Modeling Studies

Table of Contents

  	

  	



  

 

 
 	

 
 

 
 
 	 	

 

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1191
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



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1192
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



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1193
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

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1194
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

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1195
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



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Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



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1197
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

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1198
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

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1199
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



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1200
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

Figure L2-1 - Finite element mesh for Penchant Basin before refinement

$ Figure L2-2 - Finite element mesh for Penchant Basin after refinement

1201
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

Figure L2-3 - Final Penchant Basin bathymetry.

1202
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

$# Figure L2-4 - Final Lake Boudreaux and Grand Bayou Basin bathymetry

Figure L2-5 - Final Mesh Bathymetry

1203
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

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1204
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



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1205
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



   
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1206
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-7 - Eugene Island Tide Gage data adjusted to NAVD 88.

  

 
 

 
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1207
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

Figure L2-8 - All Gulf of Mexico tide gage data

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1208
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

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) +=-36$# --

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A

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EI observed Eugene Island tide gage NOAA ft NAVD

USGS ft NAVD

BP observed stage at Bayou Penchant South Morganof City

ft NAVD

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USGS ft NAVD

LAR observed stage at Lower Atchafalay Rivera Morganat City

GIWW predicted stage GIWWat RM NAVDft

Where

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obs

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1209
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-9 - Comparison of observed and predicted water surface elevation data, GIWW at RM 103.

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1210
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

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1211
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

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Table L2-1 - Root mean square error values for water surface calibration

Station RMSE

ft

BLF N of Company Canal 2.07

Company Canal @ Hwy 1 0.62

Lake Fields 0.63

GIWW E of BLF 0.77

BLF S of GIWW 1.56

GIWW W of BLF 0.23

Sulphur Mine Canal Marsh E of Grand Bayou 0.28

B, Terrebonne SE of Houma 1.03

Bayou Lafourche @ Thibodaux 2.29

Lake Cataouatche 0.73

Lake Salvador 0.29

Barataria Pass E of Grand Isle 0.19

Bayou Petit Caillou @ Cocodrie 0.40

GIWW @ Houma S of B. Terrebonne 0.67

GIWW W of Minors Canal 0.38

Bayou Penchant S of GIWW 0.23

6' 9 
 
  	  %  
&
 
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  %  &


1212
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

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1213
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

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Figure L2-10 - Upstream water surface boundary condition data for high runs

2.0

3.0

4.0

5.0

6.0

7.0

8.0

05/04/08 05/11/08 05/18/08 05/25/08 06/01/08 06/08/08 06/15/08 06/22/08 06/29/08

CST

Water Elevation (ft NAVD 88)

USGS 07381600 - Lower Atchafalaya River USGS 073814675 - Bayou Boeuf USGS 073816202 - GIWW RM 103

1214
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



3 Figure L2-11 - Tidal boundary conditions for high runs

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

05/04/08 05/11/08 05/18/08 05/25/08 06/01/08 06/08/08 06/15/08 06/22/08 06/29/08

CST

Water Elevation (ft NAVD 88)

NOAA 8762075 - Port Fourchon NOAA 8761724 - Grand Isle NOAA 8764227 - Lawma

1215
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-12 - Upstream stage boundary conditions for low runs

3 Figure L2-13 - Downstream boundary conditions for low runs

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

10/28/05 11/04/05 11/11/05 11/18/05 11/25/05 12/02/05 12/09/05 12/16/05 12/23/05

CST

Water Elevation (ft NAVD 88)

USGS 07381600 - Lower Atchafalaya River USGS 073814675 - Bayou Boeuf USGS 073816202 - GIWW RM 103

-2.0

-1.5

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0.0

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1.5

2.0

2.5

3.0

10/28/05 11/04/05 11/11/05 11/18/05 11/25/05 12/02/05 12/09/05 12/16/05 12/23/05

CST

Water Elevation (ft NAVD 88)

NOAA 8762075 - Port Fourchon NOAA 8761724 - Grand Isle USACE 88550 - Atchafalaya Bay

1216
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



$ .
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36 Table L2-2 - 2015 run geometries

Geometry Features Bayou

Boeuf Lock

ex2015 Alt 1 Open

ex2015b Alt 1 Closed

fo2015 Alt 2 Open

fo2015b Alt 2 Closed

wf2015 Alt 3 Open

wf2015b Alt 3 Closed

ef2015 Alt 4 Open

ef2015b Alt 4 Closed

bf2015 Alt 5 Open

bf2015b Alt 5 Closed

wo2105 Alt 6 Open

wo2015bw Alt 6 Closed

wo2015b* Alt 6 Closed

rp2015 Alt 8 Open

rp2015b Alt 8 Closed

* Structure WS4 is closed

Table L2-3 - 2025 run geometries

Geometry Features Bayou

Boeuf Lock

HNC

Lock

ex2025 Alt 1 Open Open

ex2025c Alt 1 Open Closed

ex2025b Alt 1 Closed Open

ex2025bc Alt 1 Closed Closed

fo2025c Alt 2 Open Closed

fo2025bc Alt 2 Closed Closed

wf2025c Alt 3 Open Closed

wf2025bc Alt 3 Closed Closed

ef2025c Alt 4 Open Closed

ef2025bc Alt 4 Closed Closed

bd2025c Alt 5 Open Closed

Geometry Features Bayou

Boeuf Lock

HNC

Lock

bf2025bc Alt 5 Closed Closed

wo2025c Alt 6 Open Closed

wo2025bwc Alt 6 Closed Closed

wo2025bc* Alt 6 Closed Closed

rp2025c Alt 8 Open Closed

rp2025bc Alt 8 Closed Closed

* Structure WS4 is closed in this geometry

33 Table L2-4 - 2065 run geometries

Geometry Features Bayou

Boeuf Lock

HNC

Lock

ex2065 Alt 1 Open Open

ex2065c Alt 1 Open Closed

ex2065b Alt 1 Closed Open

ex2065bc Alt 1 Closed Closed

fo2065c Alt 2 Open Closed

fo2065bc Alt 2 Closed Closed

wf2065c Alt 3 Open Closed

wf2065bc Alt 3 Closed Closed

ef2065c Alt 4 Open Closed

ef2065bc Alt 4 Closed Closed

bd2065c Alt 5 Open Closed

bf2065bc Alt 5 Closed Closed

wo2065c Alt 6 Open Closed

wo2065bwc Alt 6 Closed Closed

wo2065bc* Alt 6 Closed Closed

rp2065c Alt 8 Open Closed

rp2065bc Alt 8 Closed Closed

* Structure WS4 is closed in this geometry

1217
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

33

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Equation L2-2  RMA Type 3 Structure

 +)JGAM - Q  BJAJ HNHN  CJ

Equation L2-3  RMA Type 4 Structure

 +)JGAM Q  BJAJ HN  CJ

1218
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$

- Equation L2-4  RMA Type 5 Structure

GAM Exponent

CJ Coefficient

BJ Coefficient

AJ Coefficient

HN Head downstream

Where HN Head upstream

HNHN BJAJ Q GAM

























A

+)J 

Equation L2-5 - Coefficient BJ1 for Type 3 Structure

-  CAnBJ  g

Equation L2-6 - Coefficient BJ1 for Type 4 Structure

# 

-A

 +)

  

s

ft g

n Number of boxes

A Area of culvert

Where C

g CAn

BJ











- Table L2-5 - Structure coefficients for RMA 2 modeling

Feature Structure

Type

Coefficient *

BJ1 GAM1

EC2 5 1.55E-06 2.0

EC3 3 16.05 0.5

EC6 3 32.87 0.5

EC7 5 9.26E-08 2.0

EP7 4 52.00 1.5

CC3 5 6.74E-08 2.0

CC4 5 6.74E-08 2.0

CC13 5 6.74E-08 2.0

CL1 5 9.70E-08 2.0

CS1 5 6.74E-08 2.0

WS4 5 1.33E-08 2.0

* Coefficients AJ1 and CJ1 have a value of

0.0 for all structures

1219
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



	 "= 

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1220
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

-6

Figure L2-14 - Synthesized and computed monthly average stage hydrograph

@ &
 
  


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Table L2-6 - Fraction of range used, by month

Month Fraction

Jan 0.41

Feb 0.61

Mar 0.78

Apr 0.77

May 1.00

Jun 0.88

Jul 0.36

Aug 0.07

Sep 0.06

Oct 0.05

Nov 0.00

Dec 0.10

-3 Table L2-7 - Geometries used by alternative -

2015

Alternative Low

Run High Run

High

Run

Mar-Jun

1 ex2015 ex2015b ex2015b

2 fo2015 fo2015b fo2015b

3 wf2015 wf2015b fo2015b

4 ef2015 ef2105b ef2015b

5 bf2015 bf2015b ef2015b

6 wo2015 wo2015bw wo2015b

8 rp2015 Rp2051b Rp2015b

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

LAR Morgan City Stage (ft)

Monthly Average Morgan City Stage Synthesized Monthly Average

1221
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

Table L2-8 - Geometries used by alternative -

2025

Alternative Low

Run High Run High Run

Mar-Jun

1* ex2025 ex2025b ex2025bc

2 fo2025c fo2025bc fo2025bc

3 wf2025c wf2025bc fo2025bc

4 ef2025c ef2105bc ef2025bc

5 bf2025c bf2025bc ef2025bc

6 wo2025c wo2025bwc wo2025bc

7 ex2025c ex2025bc ex2025bc

8 rp2025c rp2025c rp2025bc

* ex c geometries used for Oct-Nov

--

Table L2-9 - Geometries used by alternative -

2065

Alternative Low

Run High Run High Run

Mar-Jun

1* ex2065 ex2065b ex2065b

2 fo2065c fo2065bc fo2065bc

3 wf2065c wf2065bc fo2065bc

4 ef2065c ef2105bc ef2065bc

5 bf2065c bf2065bc ef2065bc

6 wo2065c wo2065bwc wo2065bc

7 ex2065c ex2065bc ex2065bc

8 rp2065c rp2065bc rp2065bc

* ex c geometries used for Oct-Nov

--

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1222
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

' 
& # %  
  
 
      
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Table L2-10 - Summary of Sea Level Rise and Subsidence values used in Alternatives modeling

Rate

Sea Level Rise from 2004 Sea Level

2015 2025 2065

mm/yr ft/century m ft m ft m ft

Low Rate 2.28 0.75 0.025 0.082 0.048 0.157 0.139 0.456

Intermediate

(NRC Curve I) N/A N/A 0.031 0.101 0.064 0.210 0.243 0.798

High (NRC

Curve III) N/A N/A 0.071 0.232 0.156 0.512 0.698 2.291

Subsidence 7.165 2.35 0.079 0.259 0.150 0.494 0.437 1.435

$ 


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1223
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

* 

% 

 
  

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1224
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

'-  	@5,;!5* 9;*1

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1225
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to

Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#


"
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1226
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EIS WRDA 2007 Section 7006(e)(3) May 2010

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##

3

Figure L2-15 - Data sources of various model portions

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Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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Table L2-11  Data collection stations and their sampling durations and intervals

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Figure L2-16 - Location of Data Collection Sites -

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Figure L2-17 - Boundary Conditions Used in the Model

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Table L2-12 - RMA-2 calibration parameter values

Water body Element Type EV-x u-vel (lb-sec/ft2

)

EV-y u-vel

(lb-sec/ft2

)

EV-x v-vel

(lb-sec/ft2

)

EV-y v-vel

(lb-sec/ft2

)

Manning's

"n"

Bayou Terrebonne 8, 65 20 20 20 20 0.025Bayou Petit Caillou 12 20 20 20 20 0.025Bush Canal 13 20 20 20 20 0.045Boudreaux Canal 25 20 20 20 20 0.045Penchant Basin 1D channels 29-59, 61 20 20 20 20 0.025Unsurveyed Pipeline Canal in Penchant Basin 68 20 20 20 20 0.04GIWW north of Bayou Lafourche 60 20 20 20 20 0.025South Bayou Grand Caillou 62 20 20 20 20 0.025South Houma Navigation Canal 63,64 20 20 20 20 0.025South Bayou Pointe Au Chien 66 20 20 20 20 0.025Grand Bayou Blue 67 20 20 20 20 0.025All remaining 1D Channels

1-7, 9-11, 14-24,

26-28 20 20 20 20 0.02

Dummy material types

95, 98, 99, 100,

108, 118, 119

Marsh areas and marsh areas connected to Gulf 70, 81, 82 Scaled Scaled Scaled Scaled 0.03Elements by barrier islands 71 Scaled Scaled Scaled Scaled 0.025Gulf of Mexico 72 Scaled Scaled Scaled Scaled 0.03Isolated marsh areas with connections to channels 73, 74 Scaled Scaled Scaled Scaled 0.045Marsh areas connected to Gulf 69, 75-77, 80 Scaled Scaled Scaled Scaled 0.04Gulf of Mexico 78, 79 Scaled Scaled Scaled Scaled 0.03GIWW E of BLF/B. Des Allemands 83 Scaled Scaled Scaled Scaled 0.045Overbanks 84 Scaled Scaled Scaled Scaled 0.025Canals within Grand Bayou triangle 85 Scaled Scaled Scaled Scaled 0.045Marsh N of S Pipeline Canal in Grand Bayou 86 Scaled Scaled Scaled Scaled 0.045Marsh S of S Pipeline Canal in Grand Bayou 87 Scaled Scaled Scaled Scaled 0.0452D canals S of Cutoff Canal 88 Scaled Scaled Scaled Scaled 0.0452D canals S of Cutoff Canal & Grand Bayou 89 Scaled Scaled Scaled Scaled 0.035B. Blue & newly coded 2D canals E and N of Grand 90 Scaled Scaled Scaled Scaled 0.035

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Water body Element Type EV-x u-vel (lb-sec/ft2

)

EV-y u-vel

(lb-sec/ft2

)

EV-x v-vel

(lb-sec/ft2

)

EV-y v-vel

(lb-sec/ft2

)

Manning's

"n"

BayouMarsh elements east of Grand Bayou 91 Scaled Scaled Scaled Scaled 0.04Open water elements East of Grand Bayou 92 Scaled Scaled Scaled Scaled 0.032D elements as extensions to 1D channels in Gulf 93-109 Scaled Scaled Scaled Scaled 0.022D Cutoff Canal 110 Scaled Scaled Scaled Scaled 0.045Atchafalaya marsh (elev -2) 111 Scaled Scaled Scaled Scaled 0.045Atchafalaya open water (elev -5) 112 Scaled Scaled Scaled Scaled 0.03Atchafalaya 2D channel (elev -5) 113 Scaled Scaled Scaled Scaled 0.045Atchafalaya overbanks (elev +2) 114 Scaled Scaled Scaled Scaled 0.025COE Atch. Open water/2D channels 115 Scaled Scaled Scaled Scaled 0.045USACE Atch. Morgan City lock 116 Scaled Scaled Scaled Scaled 0.045USACE lower LAR 115 Scaled Scaled Scaled Scaled 0.045USACE upper LAR 115 Scaled Scaled Scaled Scaled 0.045USACE Gulf of Mexico 115 Scaled Scaled Scaled Scaled 0.045USACE overbanks/Avoca Is. Cutoff 117 Scaled Scaled Scaled Scaled 0.025Atchafalaya land/healthy marsh (elev +2) 120-129 Scaled Scaled Scaled Scaled 0.045Lapeyrouse Canal 130 Scaled Scaled Scaled Scaled 0.045

-

Table L2-13 - RMA-11 Calibration Parameters

Water body Element Type

Dispersion

Scale Factor

in XDirection

Dispersion

Scale Factor

in YDirection

Minimum

Dispersion

in XDirection

(m2/s)

Minimum

Dispersion

in YDirection

(m2/s)

Bayou Terrebonne 65 15 15 0.5 0.5Bayou Petit Caillou 12 50 50 0.5 0.5Bush Canal 13 1 1 0.5 0.5Boudreaux Canal 25 25 25 0.5 0.5Penchant Basin 1D channels 30-59, 61, 68 1 1 0.5 0.5

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#'

Water body Element Type

Dispersion

Scale Factor

in XDirection

Dispersion

Scale Factor

in YDirection

Minimum

Dispersion

in XDirection

(m2/s)

Minimum

Dispersion

in YDirection

(m2/s)

GIWW north of Bayou Lafourche 60 1 1 0.5 0.5South Bayou Grand Caillou 62 25 25 0.5 0.5South Houma Navigation Canal 63,64 25 25 0.5 0.5South Bayou Pointe Au Chien 66 25 25 0.5 0.5Grand Bayou Blue 67 25 25 0.5 0.5Grand Bayou 6 3 3 0.5 0.5St. Louis Canal 9 10 10 0.5 0.5Bayou Pointe au Chien 10 5 5 0.5 0.5Cutoff Canal south of Bayou Pointe au Chien 28 25 25 0.5 0.5Bayou Jean Lacroix south of Lake Chien 29 25 25 0.5 0.5HNC north of Bayou Gran Caillou 17 3 3 0.5 0.5Bayou Grand Caillou East of HNC 18 10 10 0.5 0.5Bayou Dulac 24 25 25 0.5 0.5Robinson Canal 26 10 10 0.5 0.5All remaining 1D Channels

1-5, 7, 8, 11, 14-16,

19-23, 27 1 1 0.5 0.5

Dummy material types

95, 98, 99, 100,

108, 118, 119

Marsh areas and marsh areas connected to Gulf 81 100 100 0.5 0.5Marsh areas connected to Gulf in Barataria Basin 82 2 2 0.5 0.5Lake Boudreaux Basin and Marshes connected to Gulf 70 1 1 0.5 0.5Elements by barrier islands 71 500 500 0.5 0.5Gulf of Mexico 72 10 10 0.5 0.5Isolated marsh areas with connections to channels 73 1 1 0.5 0.5Isolated marsh areas with connections to channels 74 5 5 0.5 0.5Open water elements in Barataria Basin 77 10 10 0.5 0.5Marsh areas connected to Gulf east of Grand Bayou Blue 69 3 3 0.5 0.5Marsh areas connected to Gulf 75, 76, 80 1 1 0.5 0.5Marshes east of Caillou Lake 78 75 75 0.5 0.5

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Water body Element Type

Dispersion

Scale Factor

in XDirection

Dispersion

Scale Factor

in YDirection

Minimum

Dispersion

in XDirection

(m2/s)

Minimum

Dispersion

in YDirection

(m2/s)

North of Barrier Islands 79 10 10 0.5 0.5GIWW E of BLF/B. Des Allemands 83 1 1 0.5 0.5Overbanks 84 1 1 0.5 0.5Canals within Grand Bayou triangle 85 25 25 0.5 0.5Marsh N of S Pipeline Canal in Grand Bayou 86 10 10 0.5 0.5Marsh S of S Pipeline Canal in Grand Bayou 87 10 10 0.5 0.52D canals S of Cutoff Canal 88 10 10 0.5 0.52D canals S of Cutoff Canal & Grand Bayou 89 5 5 0.5 0.5B. Blue & newly coded 2D canals E and N of GrandBayou 90 25 25 0.5 0.5Marsh elements east of Grand Bayou 91 3 3 0.5 0.5Open water elements East of Grand Bayou 92 5 5 0.5 0.5

2D elements as extensions to 1D channels in Gulf

93 50 50 0.5 0.5

94 10 10 0.5 0.595 100 100 0.5 0.596 50 50 0.5 0.597 50 50 0.5 0.598 100 100 0.5 0.599 100 100 0.5 0.5

101 100 100 0.5 0.5102 100 100 0.5 0.5103 100 100 0.5 0.5104 100 100 0.5 0.5105 10 10 0.5 0.5106 10 10 0.5 0.5107 2 2 0.5 0.5109 50 50 0.5 0.5

2D Cutoff Canal 110 25 25 0.5 0.5Atchafalaya marsh (elev -2) 111 10 10 0.5 0.5

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Water body Element Type

Dispersion

Scale Factor

in XDirection

Dispersion

Scale Factor

in YDirection

Minimum

Dispersion

in XDirection

(m2/s)

Minimum

Dispersion

in YDirection

(m2/s)

Atchafalaya open water (elev -5) 112 50 50 0.5 0.5Atchafalaya 2D channel (elev -5) 113 10 10 0.5 0.5Atchafalaya overbanks (elev +2) 114 10 10 0.5 0.5COE Atch. Open water/2D channels 115 75 75 0.5 0.5USACE Atch. Morgan City lock 116 10 10 0.5 0.5USACE lower LAR 115 75 75 0.5 0.5USACE upper LAR 115 75 75 0.5 0.5USACE Gulf of Mexico 115 75 75 0.5 0.5USACE overbanks/Avoca Is. Cutoff 117 10 10 0.5 0.5Atchafalaya land/healthy marsh (elev +2) 120-129 10 10 0.5 0.5

130 10 10 0.5 0.5131 10 10 0.5 0.5

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Figure L2-18 - Flow output locations from the model '

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Table L2-14 - Flow output locations from model

Point Name Point Name

0 Avoca Lake drain 25 Robinson Canal1 Avoca Island Cutoff W of Avoca Is 26 Company Canal north of GIWW2 Avoca Island Cutoff at LAR 27 GIWW east of Company Canal3 Bayou Chene E of Penchant 28 Bayou Boeuf Lock4 Bayou Penchant mouth 29 Grand Pass5 Carencro Bayou at Penchant 30 Company Canal south of GIWW6 Palmetto Bayou head 31 Bayou Terrebonne north of Humble Canal7 Bayou Boeuf 32 Humble Canal8 GIWW east of Bay Wallace 33 GIWW west of Larose9 United Gas Pipeline Canal head 34 GIWW east of Larose

10 Bayou Copasaw head 35 Bayou Lafourche north of GIWW11 Bayou Penchant below Copasaw 36 Bayou Lafourche south of GIWW12 Brady Canal head 37 Grand Bayou Canal13 GIWW middle of Penchant Basin 38 Cutoff Canal14 Minors Canal 39 Grand Bayou Blue15 GIWW west of Houma 40 Bayou Chene @ GIWW16 HNC head 41 WD217 GIWW east of Houma 42 Bayou Dulac18 HNC @ pontoon bridge 43 CS119 Falgout Canal west of HNC 44 CC1320 Falgout Canal west of DuLarge 45 EC221 HNC south of BGC 46 EC322 Bayou Grand Caillou west of HNC 47 St. Louis Canal23 Bayou Grand Caillou east of HNC 48 WS424 Boudreaux Canal

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Figure L2-19 - Stage output locations from model '

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Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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Table L2-15 - Stage output locations from model

Point Name Point Name Point Name Point Name

0 H1 26 D3 Central 52 B6 South 78 Big Carencro Bayou1 H2 West 27 C2 53 B7 North 79 H32 H2 East 28 C3 54 B7 Southeast 80 HNC North3 H2 Central 29 C1 55 B7 Southwest 81 Bayou Boeuf Lock4 G2 30 C4 56 A1 82 Bayou Boeuf at Amelia5 G3 East 31 C5 57 A3 South 83 GIWW middle of Penchant Basin6 G3 West 32 C6 58 A3 North 84 HNC head7 G6 West 33 C7 59 A4 85 GIWW west of Larose8 G6 Central 34 C8 60 A5 86 Bayou Petit Caillou nr Chauvin9 G6 Southeast 35 C9 61 A6 East 87 Bayou Chene E of Penchant

10 G7 Catfish Lake 36 C10 West 62 A6 West 88 Cutoff Canal11 G7 Northwest 37 C10 South 63 A7 89 GIWW east of Company Canal12 G7 Southeast 38 C10 North 64 A8 90 St. Louis Canal13 G1 South 39 HNC at Bayou Grand Caillou 65 A9 91 Grand Bayou Canal14 G1 North 40 HNC below Lock Complex 66 Lake Palourde 92 Bayou Terrebonne15 G5 South 41 C14 North 67 Bayou Black 93 Falgout Canal west of DuLarge16 G5 North 42 C14 Central 68 Avoca Island17 F2 43 HNC South 69 Bayou Copasaw18 F3 North 44 HNC at Falgout Canal 70 Bayou Penchant19 F3 South 45 B2 North 71 Palmetto Bayou20 E2 Northwest 46 B2 South 72 Creole Bayou21 E2 Southeast 47 B8 73 Carencro Bayou22 E3 North 48 B3 74 Lake Pagie South23 E4 North 49 B9 75 Lake Pagie North24 D3 North 50 B5 76 Lost Lake West25 D3 South 51 B6 North 77 Lost Lake East

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Figure L2-20 - Salinity output locations from the model

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Table L2-16 - Salinity output locations from model 

Point Name Point Name Point Name Point Name

0 H1 24 E4 North 48 B2 North 72 Bayou Copasaw1 H2 West 25 E4 South 49 B2 South 73 Bayou Penchant2 H2 East 26 D3 North 50 B8 74 Palmetto Bayou3 H2 Central 27 D3 South 51 B3 75 Creole Bayou4 G2 28 D3 Central 52 B9 76 Carencro Bayou5 G3 East 29 C2 53 B5 77 Lake Pagie South6 G3 West 30 C3 54 B6 North 78 Lake Pagie North7 G6 West 31 C1 55 B6 South 79 Lost Lake West8 G6 Central 32 C4 56 B7 North 80 Lost Lake East9 G6 Southeast 33 C5 57 B7 Southeast 81 Big Carencro Bayou

10 G7 Catfish Lake 34 C6 58 B7 Southwest 82 H311 G7 Northwest 35 C7 59 A1 83 HNC North12 G7 Southeast 36 C8 60 A3 South13 G1 South 37 C9 61 A3 North14 G1 North 38 C10 West 62 A415 G5 South 39 C10 South 63 A516 G5 North 40 C10 North 64 A6 East17 F2 41 HNC at Bayou Grand Caillou 65 A6 West18 F3 North 42 HNC below Lock Complex 66 A719 F3 South 43 C14 North 67 A820 E2 Northwest 44 C14 Central 68 A921 E2 Southeast 45 C14 South 69 Lake Palourde22 E3 North 46 HNC South 70 Bayou Black23 E3 South 47 HNC at Falgout Canal 71 Avoca Island

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Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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Figure L2-21 - Salinity polygons used in benefits analysis

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Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

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 RMA-2 Stage Calibration Results

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Figure L2-22 - RMA-2 calibration plot for Station 1

Figure L2-23 - RMA-2 calibration plot for Station 2

Bayou Lafourche North of Company Canal

Station 1 - Node 435

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

Company Canal at Highway 1

Station 2 - Node 15795

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

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Figure L2-24 - RMA-2 calibration plot for Station 3

Figure L2-25 - RMA-2 calibration plot for Station 4

Lake Fields

Station 3 - Node 17403

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

GIWW East of Bayou Lafourche

Station 4 - Node 21076

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

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Figure L2-26 - RMA-2 calibration plot for Station 5

Figure L2-27 - RMA-2 calibration plot for Station 6

Bayou Lafourche south of GIWW

Station 5 - Node 21057

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

GIWW West of Bayou Lafourche

Station 6 - Node 15791

0.5

1.0

1.5

2.0

2.5

3.0

3.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

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 Figure L2-28 - RMA-2 calibration plot for Station 7

Figure L2-29 - RMA-2 calibration plot for Station 8

Sulphur Mine Canal Marsh East of Grand Bayou

Station 7 - Node 13805

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

Bayou Terrebonne Southeast of Houma

Station 8 - Node 2087

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

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Figure L2-30 - RMA-2 calibration plot for Station 10



Figure L2-31 - RMA-2 calibration plot for Station 12

Bayou Lafourche at Thibodaux

Station 10 - Node 163

1

2

3

4

5

6

7

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

Lake Cataouatche

Station 12 - Node 33388

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

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Figure L2-32 - RMA-2 calibration plot for Station 13

# Figure L2-33 - RMA-2 calibration plot for Station 14

Lake Salvador

Station 13 - Node 33207

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

Barataria Pass East of Grand Isle

Station 14 - Node 22757

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

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Figure L2-34 - RMA-2 calibration plot for Station 15

Figure L2-35 - RMA-2 calibration plot for Station 16

HNC at Dulac

Station 15 - Node 11291

0.5

1.0

1.5

2.0

2.5

3.0

3.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

Bayou Petit Caillou at Cocodrie

Station 16 - Node 3534

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

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Figure L2-36 - RMA-2 calibration plot for Station 17

Figure L2-37 - RMA-2 calibration plot for Station 18

GIWW at Houma

Station 17 - Node 14653

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

GIWW West of Minors Canal

Station 18 - Node 63877

0.5

1.0

1.5

2.0

2.5

3.0

3.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

1252
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

$ Figure L2-38 - RMA-2 calibration plot for Station 19

Bayou Penchant East of Avoca Island Cutoff

Staion 19 - Node 64672

1.0

1.5

2.0

2.5

3.0

3.5

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Water Surface Elevation (ft, NAVD88)

Observed Model

1253
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

RMA-11 Salinity Calibration Results

1254
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

Figure L2-39 - RMA-11 calibration plot for Station 1

$

Figure L2-40 - RMA-11 calibration plot for Station 2

Bayou Lafourche North of Company Canal

Station 1 - Node 435

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

Company Canal at Highway 1

Station 2 - Node 15795

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1255
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

Figure L2-41 - RMA-11 calibration plot for Station 3

Lake Fields

Station 3 - Node 17403

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1256
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6



Figure L2-42 - RMA-11 calibration plot for Station 4

Figure L2-43 - RMA-11 calibration plot for Station 5

GIWW East of Bayou Lafourche

Station 4 - Node 21076

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

Bayou Lafourche south of GIWW

Station 5 - Node 21057

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1257
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6#

 Figure L2-44 - RMA-11 calibration plot for Station 6

Figure L2-45 - RMA-11 calibration plot for Station 7

GIWW West of Bayou Lafourche

Station 6 - Node 15791

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

Sulphur Mine Canal Marsh East of Grand Bayou

Station 7 - Node 13044

2

3

4

5

6

7

8

9

10

11

12

13

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1258
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6$

Figure L2-46 - RMA-11 calibration plot for Station 8

6

Figure L2-47 - RMA-11 calibration plot for Station 12

Bayou Terrebonne Southeast of Houma

Station 8 - Node 2087

0

1

2

3

4

5

6

7

8

9

10

11

12

13

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

Lake Cataouatche

Station 12 - Node 33388

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1259
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

Figure L2-48 - RMA-11 calibration plot for Station 13

6 Figure L2-49 - RMA-11 calibration plot for Station 14

Lake Salvador

Station 13 - Node 33207

1

2

3

4

5

6

7

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

Barataria Pass East of Grand Isle

Station 14 - Node 22757

12

14

16

18

20

22

24

26

28

30

32

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1260
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

66

Figure L2-50 - RMA-11 calibration plot for Station 15

Figure L2-51 - RMA-11 calibration plot for Station 16

HNC at Dulac

Station 15 - Node 11291

0

1

2

3

4

5

6

7

8

9

10

11

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

Bayou Petit Caillou at Cocodrie

Station 16 - Node 3534

0

2

4

6

8

10

12

14

16

18

20

22

24

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1261
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

63

3

Figure L2-52 - RMA-11 calibration plot for Station 17

GIWW at Houma

Station 17 - Node 14653

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

01-Oct-0408-Oct-0415-Oct-0422-Oct-0429-Oct-04

05-Nov-0412-Nov-0419-Nov-0426-Nov-04

Salinity (ppt)

Observed Model

1262
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6-

RMA-2 Flow Change Results

3 ) 
 $ 
  8

 
    "
+

1263
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6'

Figure L2-53  Flow for Alternative 1, February 2015

1264
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

Figure L2-54 - Flow for Alternative 1, May 2015

1265
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

-

Figure L2-55 - Flow for Alternative 1, November 2015

1266
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

Figure L2-56 - Flow change for Alternative 2, February 2015

1267
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3#

Figure L2-57 - Flow change for Alternative 2, May 2015 -

1268
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3$

Figure L2-58 - Flow change for Alternative 2, November 2015

1269
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

Figure L2-59 - Flow change for Alternative 3, February 2015

1270
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

36

'

Figure L2-60 - Flow change for Alternative 3, May 2015

1271
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

33

Figure L2-61 - Flow change for Alternative 3, November 2015

1272
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3-

Figure L2-62 - Flow change for Alternative 4, February 2015 '

1273
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3'

Figure L2-63 - Flow change for Alternative 4, May 2015

1274
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

Figure L2-64 - Flow change for Alternative 4, November 2015

1275
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-



Figure L2-65 - Flow change for Alternative 5, February 2015

1276
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

Figure L2-66 - Flow change for Alternative 5, May 2015

1277
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-#

Figure L2-67 - Flow change for Alternative 5, November 2015 

1278
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-$

Figure L2-68 - Flow change for Alternative 6, February 2015

1279
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

Figure L2-69 - Flow change for Alternative 6, May 2015

1280
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-6



Figure L2-70 - Flow change for Alternative 6, November 2015

1281
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-3

Figure L2-71 - Flow change for Alternative 8, February 2015

1282
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

--

Figure L2-72 - Flow change for Alternative 8, May 2015 

1283
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-'

Figure L2-73 - Flow change for Alternative 8, November 2015

1284
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

Figure L2-74 - Flow for Alternative 1, February 2025

1285
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'



Figure L2-75 - Flow for Alternative 1, May 2025

1286
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

Figure L2-76 - Flow for Alternative 1, November 2025

1287
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'#

Figure L2-77 - Flow change for Alternative 2, February 2025 

1288
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'$

Figure L2-78 - Flow change for Alternative 2, May 2025

1289
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

Figure L2-79 - Flow change for Alternative 2, November 2025

1290
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'6

#

Figure L2-80 - Flow change for Alternative 3, February 2025

1291
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'3

Figure L2-81 - Flow change for Alternative 3, May 2025

1292
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'-

Figure L2-82 - Flow change for Alternative 3, November 2025 #

1293
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

''

Figure L2-83 - Flow change for Alternative 4, February 2025

1294
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-84 - Flow change for Alternative 4, May 2025

1295
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



$

Figure L2-85 - Flow change for Alternative 4, November 2025

1296
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-86 - Flow change for Alternative 5, February 2025

1297
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

Figure L2-87 - Flow change for Alternative 5, May 2025 $

1298
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$

Figure L2-88 - Flow change for Alternative 5, November 2025

1299
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-89 - Flow change for Alternative 6, February 2025

1300
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6



Figure L2-90 - Flow change for Alternative 6, May 2025

1301
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

Figure L2-91 - Flow change for Alternative 6, November 2025

1302
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

Figure L2-92 - Flow change for Alternative 7, February 2025 

1303
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

Figure L2-93 - Flow change for Alternative 7, May 2025

1304
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-94 - Flow change for Alternative 8, February 2025 6

1305
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-95 - Flow change for Alternative 8, May 2025

1306
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



6

Figure L2-96 - Flow change for Alternative 8, November 2025

1307
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

Table L2-17 - Flow Change Summary for 2015

1308
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$

3

1309
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



1310
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

*"
 -  /

%   
 

1311
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

3

1312
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

1313
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

RMA-2 Water Surface Elevation Change Results

) 
 $ 
  8

 
    "
+

1314
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-97 - Monthly averaged water surface impact for Alternative 2, 2015 -

1315
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-98 - Monthly averaged water surface impact for Alternative 3, 2015

1316
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-99 - Monthly averaged water surface impact for Alternative 4, 2015

1317
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

-

Figure L2-100 - Monthly averaged water surface impact for Alternative 5, 2015

1318
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$

Figure L2-101 - Monthly averaged water surface impact for Alterative 6, 2015

1319
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



'

Figure L2-102 - Monthly averaged water surface impact for Alternative 8, 2015

1320
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

Table L2-19 - Stage impact summary 2015

1321
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

'

1322
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

1323
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

1324
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

1325
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

#

1326
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern

Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

RMA-11 Average Annual Salinity Change Results

) 
 $ 
  8

 
    "
+

1327
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Houma Navigation Lock

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##

Figure L2-103 - Average annual salinity for Alternative 1, 2015

1328
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#$

#

Figure L2-104 - Average annual salinity change for Alternative 2, 2015

1329
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

Figure L2-105 - Average annual salinity change for Alternative 3, 2015

1330
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

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#6

Figure L2-106 - Average annual salinity change for Alternative 4, 2015 #

1331
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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#3

Figure L2-107 - Average annual salinity change for Alternative 5, 2015

1332
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#-

Figure L2-108 - Average annual salinity change for Alternative 6, 2015

#

1333
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#'

Figure L2-109 - Average annual salinity change for Alternative 8, 2015

1334
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$

Figure L2-110 - Average annual salinity for Alternative 1, 2025

1335
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$

#

Figure L2-111 - Average annual salinity change for Alternative 2, 2025

1336
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$

Figure L2-112 - Average annual salinity change for Alternative 3, 2025

1337
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$#

Figure L2-113 - Average annual salinity change for Alternative 4, 2025 #

1338
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$$

Figure L2-114 - Average annual salinity change for Alternative 5, 2025

1339
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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EIS WRDA 2007 Section 7006(e)(3) May 2010

$

Figure L2-115 - Average annual salinity change for Alternative 6, 2025

1340
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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$6

##

Figure L2-116 - Average annual salinity change for Alternative 7, 2025

1341
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$3

Figure L2-117 - Average annual salinity change for Alternative 8, 2025

##

1342
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$-

Figure L2-118 - Average annual salinity for Alternative 1, 2065

1343
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

$'

Figure L2-119 - Average annual salinity change for Alternative 2, 2065

1344
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

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#$

Figure L2-120 - Average annual salinity change for Alternative 3, 2065

1345
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Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-121 - Average annual salinity change for Alternative 4, 2065

1346
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010



Figure L2-122 - Average annual salinity change for Alternative 5, 2065 #$

1347
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

#

Figure L2-123 - Average annual salinity change for Alternative 6, 2065

1348
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

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$

Figure L2-124 - Average annual salinity change for Alternative 7, 2065

#

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Houma Navigation Lock

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Figure L2-125 - Average annual salinity change for Alternative 8, 2065

1350
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Houma Navigation Lock

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6

Table L2-20 - Salinity change summary, 2015

#

1351
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

3

1352
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Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

-

1353
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

'

1354
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Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

1355
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Houma Navigation Lock

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6

#6

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Houma Navigation Lock

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6

#6 Table L2-21 - Salinity change summary for 2025

1357
Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6#

#3

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Volume III  Appendix L  Annex 2  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6$

1359
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Houma Navigation Lock

EIS WRDA 2007 Section 7006(e)(3) May 2010

6

#3

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66

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Houma Navigation Lock

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63

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6-

#- Table L2-22 - Salinity change summary for 2065

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Houma Navigation Lock

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6'

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Houma Navigation Lock

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3

#-

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3

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Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock

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RMA-11 Maximum Monthly Salinity Change Results


 
 
         !

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Figure L2-126 - Maximum monthly salinity change for Alternative 2, 2015

1370
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"

		

Figure L2-127 - Maximum monthly salinity change for Alternative 3, 2015

1371
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Figure L2-128 - Maximum monthly salinity change for Alternative 4, 2015

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EIS WRDA 2007 Section 7006(e)(3) May 2010

#

Figure L2-129 - Maximum monthly salinity change for Alternative 5, 2015 	


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Figure L2-130 - Maximum monthly salinity change for Alternative 6, 2015

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EIS WRDA 2007 Section 7006(e)(3) May 2010

#	

Figure L2-131 - Maximum monthly salinity change for Alternative 8, 2015 	

1375
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#

Figure L2-132 - Maximum monthly salinity change for Alternative 2, 2025

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Figure L2-133 - Maximum monthly salinity change for Alternative 3, 2025

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#




Figure L2-134 - Maximum monthly salinity change for Alternative 4, 2025

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Figure L2-135 - Maximum monthly salinity change for Alternative 5, 2025

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Figure L2-136 - Maximum monthly salinity change for Alternative 6, 2025 	

1380
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#"

Figure L2-137 - Maximum monthly salinity change for Alternative 7, 2025

1381
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Figure L2-138 - Maximum monthly salinity change for Alternative 8, 2025 


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Figure L2-139 - Maximum monthly salinity change for Alternative 2, 2065

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Figure L2-140 - Maximum monthly salinity change for Alternative 3, 2065

1384
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Figure L2-141 - Maximum monthly salinity change for Alternative 4, 2065

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Figure L2-142 - Maximum monthly salinity change for Alternative 5, 2065

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Figure L2-143 - Maximum monthly salinity change for Alternative 6, 2065 


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Figure L2-144 - Maximum monthly salinity change for Alternative 7, 2065

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Figure L2-145 - Maximum monthly salinity change for Alternative 8, 2065 	

1389

 	



 

 

1391
ATCHAFALAYA FRESHWATER

CONVEYANCE PROJECT

HYDROLOGIC MODELING REPORT

SENSITIVITY ANALYSIS

MAY 12, 2010

1392
ATCHAFALAYA FRESHWATER CONVEYANCE PROJECT

HYDROLOGIC MODELING REPORT

SENSITIVITY ANALYSIS

Prepared for

US Army Corps of Engineers

St. Louis District

1222 Spruce Street RM 4207

St. Louis, MO 63103-2833

Prepared by

FTN Associates, Ltd.

3 Innwood Circle, Suite 220

Little Rock, AR 72211

FTN No. 1160-066.001

May 12, 2010

1393
May 12, 2010

i

TABLE OF CONTENTS

1.0 INTRODUCTION ...............................................................................................................1

2.0 SENSITIVITY ANALYSIS SETUP ...................................................................................2

2.1 Mannings n Values .................................................................................................2

2.2 Eddy Coefficients.....................................................................................................3

2.3 Diffusion Coefficients..............................................................................................6

3.0 MODEL SIMULATIONS .................................................................................................10

4.0 RESULTS ..........................................................................................................................11

5.0 CONCLUSIONS................................................................................................................15

LIST OF APPENDICES

APPENDIX A: Water Surface Elevation and Salinity Time-Series Plots for Mannings n

Sensitivity Analysis

APPENDIX B: Water Surface Elevation and Salinity Time-Series Plots for Eddy

Coefficient Sensitivity Analysis

APPENDIX C: Salinity Time-Series Plots for Diffusion Coefficient Sensitivity Analysis

APPENDIX D: Salinity Isohalines

1394
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ii

LIST OF TABLES

Table 1 Base, low, and high values for Mannings n by material type................................ 4

Table 2 Base, low, and high values for eddy coefficients and scale factors

by material type....................................................................................................... 6

Table 3 Base, low, and high values for the diffusion coefficient scale factors.................... 8

Table 4 Maximum and minimum differences in water surface elevations

for the Mannings n and eddy coefficient sensitivity analyses............................. 12

Table 5 Maximum and minimum differences in salinity for the Mannings n,

eddy coefficient, and diffusion coefficient sensitivity analyses ........................... 13

1395
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1

1.0 INTRODUCTION

The St. Louis District of the US Army Corps of Engineers (USACE) contracted with

FTN Associates, Ltd. (FTN) (Contract No. W912P8-07-D-0060) to develop and calibrate a

hydrodynamic model for the Atchafalaya Freshwater Conveyance Project for use in the selection

of preferred project construction features to distribute existing Atchafalaya River freshwater

flows into deteriorating portions of the Penchant and northern Terrebonne basins. The results of

that study were documented in FTNs report to USACE entitled Atchafalaya Freshwater

Conveyance Project Hydrologic Modeling Report, dated February 8, 2010. The St. Louis District

modified FTNs contract to perform a sensitivity analysis on the calibrated model to analyze

ranges of input coefficients in the calibrated RMA-2 and RMA-11 models. The three input

coefficients investigated in the sensitivity analysis were Mannings n values, eddy coefficients,

and diffusion coefficients. This report documents the methodology and findings of the sensitivity

analysis. This report is intended as a supplement to the original report and does not repeat all of

the pertinent information in the original report.

1396
May 12, 2010

2

2.0 SENSITIVITY ANALYSIS SETUP

The St. Louis District provided a revised version of the model geometry FTN developed

for the original project. This revised model geometry was used for all of the sensitivity analysis

runs. The St. Louis District also provided hotstart files and model input files for both RMA-2 and

RMA-11 that were used as the base conditions for the sensitivity analysis. The same time period

(October through November of 2004) and boundary conditions were used for the base model

simulations and the sensitivity analysis simulations.

The basic concept of the sensitivity analysis was to execute RMA-2 and RMA-11 model

simulations using the base parameters provided by the St. Louis District, then change the input

coefficients and perform additional simulations for comparison with the results of the base

simulations. Each parameter of interest was varied with high and low values representing a

reasonable range for the parameter. RMA-2 simulations were performed with high and low

values for Mannings n and eddy coefficients. RMA-11 simulations using these RMA-2 results

were executed using the base diffusion coefficients. Thus, any differences in RMA-11 results for

the Mannings n and eddy coefficient sensitivity analysis would be due to differences in the

depth and velocity fields computed by RMA-2. Similarly, the base conditions RMA-2 results

were used to drive the RMA-11 simulations in the diffusion coefficient sensitivity analysis. Any

differences in the RMA-11 results for the diffusion coefficient sensitivity analysis would be

solely due to the effect of the diffusion coefficients.

2.1 Mannings n Values

A range of Mannings n values were used for different material types in the base model.

The Mannings n values were used as a calibration parameter in the original model simulations,

so the base conditions Mannings n values reflect the results of the calibration process. For the

sensitivity analysis, the base Mannings n values were reduced by 25% for the low parameter

values, and increased by 25% for the high parameter values. There was one exception to this

model setup  the low Mannings n RMA-2 simulation crashed during week 1 at a weir

connection to Grand Bayou, which is material type 86. The base Mannings n value for material

1397
May 12, 2010

3

type 86 was 0.045. The 25% reduction resulted in a Mannings n value of 0.034. To prevent

RMA-2 instability, the low Mannings n value for material type 86 was increased to 0.040,

representing an 11% reduction of the base value. The low Mannings n RMA-2 simulation was

executed with this revised value with no further problems. Table 1 shows the base, low, and high

values for Mannings n by material type.

2.2 Eddy Coefficients

According to Users Guide to RMA2 WES Version 4.5, turbulence exchange is fluid

momentum transfer associated with the chaotic motion of fluid particles, and can be viewed as

the temporal effects occurring at time scales smaller than the model time step. In RMA-2, eddy

(turbulence exchange) coefficients are specified as eddy viscosities associated with all four

combinations of direction and velocity components. The u-velocity is in the x-direction, and the

v-velocity is in the y-direction. Thus, the four eddy coefficients are of the form Eij, where

i = direction and j = velocity component. The four eddy coefficients are Exu, Eyu, Exv, and Eyv.

The eddy coefficients theoretically represent both molecular viscosity and the effects of

turbulence from Reynolds stress; however, the Reynolds stress terms are orders of magnitude

larger than the effects of molecular viscosity, so the molecular viscosity is ignored.

In RMA-2, there are two options available for specifying the eddy coefficients. The first

option is the direct specification of the numerical eddy coefficients. The second option is the

specification of a scale factor applied to a representative length of the element in the coordinate

direction. As element sizes increase, the eddy coefficient should increase. Therefore, for eddy

coefficients in the x-direction (Exu and Exv), the program calculates a representative length of the

element in the x-direction and multiplies the representative length by the specified scale factor to

compute the eddy coefficient for that element. The program does the same thing for eddy

coefficients in the y-direction (Eyu and Eyv).

1398
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4

Table 1. Base, low, and high values for Mannings n by material type.

Material

Type

Manning's n Material

Type

Manning's n

Base Low High Base Low High

1 0.020 0.015 0.025 66 0.025 0.019 0.031

2 0.020 0.015 0.025 67 0.025 0.019 0.031

3 0.020 0.015 0.025 68 0.040 0.030 0.050

4 0.020 0.015 0.025 69 0.040 0.030 0.050

5 0.020 0.015 0.025 70 0.030 0.023 0.038

6 0.020 0.015 0.025 71 0.025 0.019 0.031

7 0.020 0.015 0.025 72 0.030 0.023 0.038

8 0.025 0.019 0.031 73 0.045 0.034 0.056

9 0.020 0.015 0.025 74 0.045 0.034 0.056

10 0.020 0.015 0.025 75 0.040 0.030 0.050

11 0.020 0.015 0.025 76 0.040 0.030 0.050

12 0.025 0.019 0.031 77 0.040 0.030 0.050

13 0.045 0.034 0.056 78 0.030 0.023 0.038

14 0.020 0.015 0.025 79 0.030 0.023 0.038

15 0.020 0.015 0.025 80 0.040 0.030 0.050

16 0.020 0.015 0.025 81 0.030 0.023 0.038

17 0.020 0.015 0.025 82 0.030 0.023 0.038

18 0.020 0.015 0.025 83 0.045 0.034 0.056

19 0.020 0.015 0.025 84 0.025 0.019 0.031

20 0.020 0.015 0.025 85 0.045 0.034 0.056

21 0.020 0.015 0.025 86 0.045 0.040 0.056

22 0.020 0.015 0.025 87 0.045 0.034 0.056

23 0.020 0.015 0.025 88 0.045 0.034 0.056

24 0.020 0.015 0.025 89 0.035 0.026 0.044

25 0.045 0.034 0.056 90 0.035 0.026 0.044

26 0.020 0.015 0.025 91 0.040 0.030 0.050

27 0.020 0.015 0.025 92 0.030 0.023 0.038

28 0.020 0.015 0.025 93 0.020 0.015 0.025

29 0.025 0.019 0.031 94 0.020 0.015 0.025

30 0.025 0.019 0.031 95 0.020 0.015 0.025

31 0.025 0.019 0.031 96 0.020 0.015 0.025

32 0.025 0.019 0.031 97 0.020 0.015 0.025

33 0.025 0.019 0.031 98 0.020 0.015 0.025

34 0.025 0.019 0.031 99 0.020 0.015 0.025

35 0.025 0.019 0.031 100 0.020 0.015 0.025

36 0.025 0.019 0.031 101 0.020 0.015 0.025

37 0.025 0.019 0.031 102 0.020 0.015 0.025

38 0.025 0.019 0.031 103 0.020 0.015 0.025

1399
May 12, 2010

Table 1. Base, low, and high values for Mannings n by material type (continued).

5

Material

Type

Manning's n Material

Type

Manning's n

Base Low High Base Low High

39 0.025 0.019 0.031 104 0.020 0.015 0.025

40 0.025 0.019 0.031 105 0.020 0.015 0.025

41 0.025 0.019 0.031 106 0.020 0.015 0.025

42 0.025 0.019 0.031 107 0.020 0.015 0.025

43 0.025 0.019 0.031 108 0.020 0.015 0.025

44 0.025 0.019 0.031 109 0.020 0.015 0.025

45 0.025 0.019 0.031 110 0.045 0.034 0.056

46 0.025 0.019 0.031 111 0.045 0.034 0.056

47 0.025 0.019 0.031 112 0.030 0.023 0.038

48 0.025 0.019 0.031 113 0.045 0.034 0.056

49 0.025 0.019 0.031 114 0.025 0.019 0.031

50 0.025 0.019 0.031 115 0.045 0.034 0.056

51 0.025 0.019 0.031 116 0.045 0.034 0.056

52 0.025 0.019 0.031 117 0.025 0.019 0.031

53 0.025 0.019 0.031 118 0.045 0.034 0.056

54 0.025 0.019 0.031 119 0.045 0.034 0.056

55 0.025 0.019 0.031 120 0.045 0.034 0.056

56 0.025 0.019 0.031 121 0.045 0.034 0.056

57 0.025 0.019 0.031 122 0.045 0.034 0.056

58 0.025 0.019 0.031 123 0.045 0.034 0.056

59 0.025 0.019 0.031 124 0.045 0.034 0.056

60 0.025 0.019 0.031 125 0.045 0.034 0.056

61 0.025 0.019 0.031 126 0.045 0.034 0.056

62 0.025 0.019 0.031 127 0.045 0.034 0.056

63 0.025 0.019 0.031 128 0.045 0.034 0.056

64 0.025 0.019 0.031 129 0.045 0.034 0.056

65 0.025 0.019 0.031 130 0.045 0.034 0.056

1400
May 12, 2010

6

For the base model, eddy coefficients for one-dimensional (1-D) elements were specified

as direct numerical values. For the sensitivity analysis, the 1-D eddy coefficients were reduced

by 50% for the low values and increased by 100% for the high values. For 2-D elements,

scale factors were specified in the base model. The base eddy scale factors were 0.2 for Exu and

1.0 for Eyv, Exv, and Eyv. For the high eddy scale factors, all scale factors were set equal to 1.0.

This value was chosen because it is not reasonable to use a scale factor larger than the

representative length of the element. For the low eddy scale factors, the base scale factors were

initially reduced by 50%. This resulted in an unstable model that was unable to run the

simulations. After considerable trial and error, the low eddy scale factors were set at 0.15 for

Exu and 0.5 for Eyu, Exv, and Eyv. The only exception was that material type 113 had to be set to

the original eddy scale factors to prevent model instability. Table 2 shows the base, low, and

high values for eddy coefficients and scale factors by material type. Negative values in Table 2

indicate scale factors, as entered on the RMA-2 ED card.

Table 2. Base, low, and high values for eddy coefficients and scale factors by material type.

Material

Type

Base Low High

Exu Eyu Exv Eyv Exu Eyu Exv Eyv Exu Eyu Exv Eyv

1  67, 130 20 20 20 20 10 10 10 10 40 40 40 40

113 -0.2 -1 -1 -1 -0.2 -1 -1 -1 -1 -1 -1 -1

68  129 -0.2 -1 -1 -1 -0.15 -0.5 -0.5 -0.5 -1 -1 -1 -1

2.3 Diffusion Coefficients

The diffusion coefficients are specified in RMA-11. There are two required coefficients,

one for the x-direction and one for the y-direction. Conceptually, the coefficients reflect the

influence of turbulent behavior in the convective field. According to the Users Guide to RMA4

WES Version 4.5, convection is usually the dominant transport process, and mixing may have a

relatively minor effect on the results. The diffusion coefficients have a somewhat arbitrary

physical basis and are typically used as calibration parameters in water quality analyses.

In RMA-11, there are a number of options that affect how the diffusion coefficients are

specified and applied. These are selected by the IDIFF field on the C1 card. The base model uses

option 1, which has the following implications: horizontal diffusion coefficients are applied in

1401
May 12, 2010

7

the direction of flow. For the longitudinal direction, the diffusion coefficients are computed from

the element size and velocity magnitude, and are scaled by the input value on the DF card. The

transverse diffusion coefficients are calculated by a further scale factor times the longitudinal

diffusion coefficient. Thus, there are two scale factors on the DF card corresponding with these

definitions. In the base model, the same value is always specified for both scale factors, although

the magnitude changes depending on material type as a result of the calibration process. There is

also a minimum value for the lateral and longitudinal diffusion coefficients, which is always

specified as 0.50 in both directions regardless of material type or the value of the scale factors.

The approach for the diffusion coefficient sensitivity analysis was to reduce the

magnitude of the scale factors by 50% for the low values and increase the magnitude of the

scale factors by 100% for the high values. Table 3 shows the base, low, and high values for the

diffusion coefficient scale factors.

1402
May 12, 2010

8

Table 3. Base, low, and high values for the diffusion coefficient scale factors.

1403
May 12, 2010

9

Table 3. Base, low, and high values for the diffusion coefficient scale factors (continued).

1404
May 12, 2010

10

3.0 MODEL SIMULATIONS

A few RMA-2 model instabilities were encountered during the sensitivity analysis

simulations that affected the selection of values for the parameters. As previously noted, the

low Mannings n simulation was unstable and diverged at a weir connection between Grand

Bayou and the 2-D marsh, so the Mannings n value for Grand Bayou was slightly increased.

There were considerable RMA-2 model instabilities associated with the initial low eddy

coefficients. At first, the eddy coefficients for individual material types where instabilities

occurred were increased. This approach had to be abandoned because as one problem area was

corrected, another one occurred in a different material type. Ultimately, the eddy scale factors

were increased for all material types until model stability was achieved. These results

demonstrate that model convergence is generally aided by higher Mannings n values and eddy

coefficients, resulting in a model system that is more damped.

Results from the model simulations were extracted at the same locations that were used

as calibration points for the base model. The model results for water surface elevation and

salinity at these locations were imported into a spreadsheet, and time-series plots were created to

compare the sensitivity analysis results with the base model results. In addition, salinity

isohalines comparing high and low parameter values were generated at a snapshot in time

(November 3, 2004, 7:15 AM) to show the differences in salinity distribution for the sensitivity

analysis. This date and time was chosen because the time-series plots at the calibration stations

indicated relatively large differences in salinity at this point.

1405
May 12, 2010

11

4.0 RESULTS

Time-series plots for the base conditions and sensitivity analysis simulations at the

calibration stations are included as appendices to this report. Appendix A contains RMA-2 water

surface elevation and RMA-11 salinity time-series plots for the Mannings n sensitivity analysis.

Appendix B contains RMA-2 water surface elevation time-series plots and RMA-11 salinity

time-series plots for the eddy coefficient sensitivity analysis. Appendix C contains RMA-11

salinity time-series plots for the diffusion coefficient sensitivity analysis results. All time-series

plots in the appendices also include the observed data at the calibration stations so that the

impact of the model coefficients on the calibration can be assessed. Isohalines generated for the

sensitivity analysis are found in Appendix D. Table 4 shows the maximum and minimum

differences in water surface elevation for the Mannings n and eddy coefficient sensitivity

analyses. Table 5 shows the maximum and minimum differences in salinity for the Mannings n,

eddy coefficient, and diffusion coefficient salinity analyses.

The results of the sensitivity analysis indicate that, in general, both RMA-2 and RMA-11

model results are more sensitive to Mannings n values than the eddy scale factors. The variation

in eddy scale factors had very little effect on RMA-2 or RMA-11 model results as compared to

the base conditions results. Although the variation in Mannings n values had more impact on the

RMA-2 and RMA-11 results, the effects were not deemed significant enough to materially

improve the model calibration for water surface elevation or salinity.

1406
May 12, 2010

12

Table 4. Maximum and minimum differences in water surface elevations for the Mannings n and eddy coefficient

sensitivity analyses.

1407
May 12, 2010

13

Table 5. Maximum and minimum differences in salinity for the Mannings n, eddy coefficient, and diffusion coefficient

sensitivity analyses.

1408
May 12, 2010

14

As could be expected, the diffusion coefficients had a significant effect on the salinity

results. For some calibration stations on Company Canal (stations 1 and 2), the salinity

calibration results were significantly improved for the high diffusion coefficients. At other

stations (e.g., station 12  Lake Cataouatche and station 13  Lake Salvador) the salinity

calibration results are significantly worse for the high diffusion coefficients. These results

might imply that some improvement to the salinity calibration might be possible by selectively

increasing the diffusion coefficients for some material types. However, considerable effort was

expended in the base model salinity calibration, and it was found that the diffusion coefficients

selected were optimum for balancing the overall calibration results. Some of the trends

associated with higher and lower diffusion coefficients had already been observed during the

salinity calibration of the base model. Therefore, it is not believed that the salinity calibration

could be materially improved.

1409
May 12, 2010

15

5.0 CONCLUSIONS

A sensitivity analysis was performed on the base conditions Atchafalaya Freshwater

Conveyance Project RMA-2 and RMA-11 models that investigated the sensitivity of the model

results to variations in Mannings n, eddy coefficients, and diffusion coefficients. The sensitivity

analysis results were compared to the calibrated base model results. It was found that varying the

parameters did not significantly improve the calibration of the base model.

1410
APPENDIX A

Water Surface Elevation and Salinity Time-Series Plots

for Mannings n Sensitivity Analysis

1411
6.0

5.55.04.54.03.53 0

urface Elevation (ft, NAVD88) S

Bayou Lafourche North of Company Canal

Station 1 - Node 435

3

2.52.01.51.0

.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1412
3.5

3.02.52.01.5

urface Elevation (ft, NAVD88) S

Company Canal at Highway 1

Station 2 - Node 15795

1.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1413
4.5

4.03.53.02.5

urface Elevation (ft, NAVD88) S

Lake Fields

Station 3 - Node 17403

2.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1414
5.0

4.54.03.53.0

urface Elevation (ft, NAVD88) S

GIWW East of Bayou Lafourche

Station 4 - Node 21076

2.52.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1415
5.0

4.54.03.53.0

urface Elevation (ft, NAVD88) S

Bayou Lafourche south of GIWW

Station 5 - Node 21057

2.52.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1416
3.5

3.02.52.0

urface Elevation (ft, NAVD88) S

GIWW West of Bayou Lafourche

Station 6 - Node 15791

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1417
4.0

3.53.02.52.0

urface Elevation (ft, NAVD88) S

Sulphur Mine Canal Marsh East of Grand Bayou

Station 7 - Node 13805

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1418
5.0

4.54.03.53.02.5

urface Elevation (ft, NAVD88) S

Bayou Terrebonne Southeast of Houma

Station 8 - Node 2087

2.01.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1419
7

654

urface Elevation (ft, NAVD88) S

Bayou Lafourche at Thibodaux

Station 10 - Node 163

321

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1420
3.5

3.02.52.01.5

urface Elevation (ft, NAVD88) S

Lake Cataouatche

Station 12 - Node 33388

-0.5

1.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1421
4.0

3.53.02.52.0

urface Elevation (ft, NAVD88) S

Lake Salvador

Station 13 - Node 33207

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1422
4.5

4.03.53.02.52.0

urface Elevation (ft, NAVD88) S

Barataria Pass East of Grand Isle

Station 14 - Node 22757

1.51.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1423
3.5

3.02.52.0

urface Elevation (ft, NAVD88) S

HNC at Dulac

Station 15 - Node 11291

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1424
4.0

3.53.02.52.0

urface Elevation (ft, NAVD88) S

Bayou Petit Caillou at Cocodrie

Station 16 - Node 3534

1.51.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1425
3.5

3.02.52.01.5

urface Elevation (ft, NAVD88) S

GIWW at Houma

Station 17 - Node 14653

1.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1426
3.5

3.02.52.0

urface Elevation (ft, NAVD88) S

GIWW West of Minors Canal

Station 18 - Node 63877

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1427
3.5

3.02.5

urface Elevation (ft, NAVD88) S

Bayou Penchant East of Avoca Island Cutoff

Staion 19 - Node 64672

2.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-n High-n

1428
0.40

0.350.300.250.20

Salinity (ppt)

Bayou Lafourche North of Company Canal

Station 1 - Node 435

0.150.100.050.00

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1429
0.40

0.350.300.250.20

Salinity (ppt)

Company Canal at Highway 1

Station 2 - Node 15795

0.150.100.050.00

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1430
0.40

0.350.300.250.20

Salinity (ppt)

Lake Fields

Station 3 - Node 17403

0.150.100.050.00

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1431
2.4

2.22.01.81.61.41.21.0

Salinity (ppt)

GIWW East of Bayou Lafourche

Station 4 - Node 21076

0.80.60.40.20.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1432
2.2

2.01.81.61.41.21.0

Salinity (ppt)

Bayou Lafourche south of GIWW

Station 5 - Node 21057

0.80.60.40.20.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1433
3.2

3.02.82.62.42.22.01.81.61.4

Salinity (ppt)

GIWW West of Bayou Lafourche

Station 6 - Node 15791

1.21.00.80.60.40.20.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1434
9

87

13121110

Salinity (ppt)

Sulphur Mine Canal Marsh East of Grand Bayou

Station 7 - Node 13044

65432

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1435
9

876

13121110

Salinity (ppt)

Bayou Terrebonne Southeast of Houma

Station 8 - Node 2087

543210

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1436
1.6

1.51.41.31.21.11.00.90.8

Salinity (ppt)

Lake Cataouatche

Station 12 - Node 33388

0.70.60.50.40.30.20.1

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1437
7

654

Salinity (ppt)

Lake Salvador

Station 13 - Node 33207

321

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1438
32

302826242220181614

Salinity (ppt)

Barataria Pass East of Grand Isle

Station 14 - Node 22757

86420

1210

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1439
9

8765

1110

Salinity (ppt)

HNC at Dulac

Station 15 - Node 11291

43210

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1440
24

22201816141210

Salinity (ppt)

Bayou Petit Caillou at Cocodrie

Station 16 - Node 3534

86420

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1441
0.16

0.140.120.100.08

Salinity (ppt)

GIWW at Houma

Station 17 - Node 14653

0.060.040.020.00

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-n High-n

1442
APPENDIX B

Water Surface Elevation and Salinity Time-Series Plots

for Eddy Coefficient Sensitivity Analysis

1443
6.0

5.55.04.54.03.53 0

urface Elevation (ft, NAVD88) S

Bayou Lafourche North of Company Canal

Station 1 - Node 435

3

2.52.01.51.0

.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1444
3.5

3.02.52.01.5

urface Elevation (ft, NAVD88) S

Company Canal at Highway 1

Station 2 - Node 15795

1.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1445
4.5

4.03.53.02.5

urface Elevation (ft, NAVD88) S

Lake Fields

Station 3 - Node 17403

2.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1446
5.0

4.54.03.53.0

urface Elevation (ft, NAVD88) S

GIWW East of Bayou Lafourche

Station 4 - Node 21076

2.52.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1447
5.0

4.54.03.53.0

urface Elevation (ft, NAVD88) S

Bayou Lafourche south of GIWW

Station 5 - Node 21057

2.52.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1448
3.5

3.02.52.0

urface Elevation (ft, NAVD88) S

GIWW West of Bayou Lafourche

Station 6 - Node 15791

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1449
4.0

3.53.02.52.0

urface Elevation (ft, NAVD88) S

Sulphur Mine Canal Marsh East of Grand Bayou

Station 7 - Node 13805

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1450
5.0

4.54.03.53.02.5

urface Elevation (ft, NAVD88) S

Bayou Terrebonne Southeast of Houma

Station 8 - Node 2087

2.01.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1451
7

654

urface Elevation (ft, NAVD88) S

Bayou Lafourche at Thibodaux

Station 10 - Node 163

321

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1452
3.5

3.02.52.01.5

urface Elevation (ft, NAVD88) S

Lake Cataouatche

Station 12 - Node 33388

-0.5

1.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1453
4.0

3.53.02.52.0

urface Elevation (ft, NAVD88) S

Lake Salvador

Station 13 - Node 33207

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1454
4.5

4.03.53.02.52.0

urface Elevation (ft, NAVD88) S

Barataria Pass East of Grand Isle

Station 14 - Node 22757

1.51.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1455
3.5

3.02.52.0

urface Elevation (ft, NAVD88) S

HNC at Dulac

Station 15 - Node 11291

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1456
4.0

3.53.02.52.0

urface Elevation (ft, NAVD88) S

Bayou Petit Caillou at Cocodrie

Station 16 - Node 3534

1.51.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1457
3.5

3.02.52.01.5

urface Elevation (ft, NAVD88) S

GIWW at Houma

Station 17 - Node 14653

1.00.50.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1458
3.5

3.02.52.0

urface Elevation (ft, NAVD88) S

GIWW West of Minors Canal

Station 18 - Node 63877

1.51.00.5

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1459
3.5

3.02.5

urface Elevation (ft, NAVD88) S

Bayou Penchant East of Avoca Island Cutoff

Station 19 - Node 64672

2.01.51.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

S Water

Observed Base Low-Eddy High-Eddy

1460
0.40

0.350.300.250.20

Salinity (ppt)

Bayou Lafourche North of Company Canal

Station 1 - Node 435

0.150.100.050.00

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-Eddy High-Eddy

1461
0.40

0.350.300.250.20

Salinity (ppt)

Company Canal at Highway 1

Station 2 - Node 15795

0.150.100.050.00

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-Eddy High-Eddy

1462
0.40

0.350.300.250.20

Salinity (ppt)

Lake Fields

Station 3 - Node 17403

0.150.100.050.00

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-Eddy High-Eddy

1463
2.4

2.22.01.81.61.41.21.0

Salinity (ppt)

GIWW East of Bayou Lafourche

Station 4 - Node 21076

0.80.60.40.20.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-Eddy High-Eddy

1464
2.2

2.01.81.61.41.21.0

Salinity (ppt)

Bayou Lafourche south of GIWW

Station 5 - Node 21057

0.80.60.40.20.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-Eddy High-Eddy

1465
3.2

3.02.82.62.42.22.01.81.61.4

Salinity (ppt)

GIWW West of Bayou Lafourche

Station 6 - Node 15791

1.21.00.80.60.40.20.0

01-Oct-04

08-Oct-04

15-Oct-04

22-Oct-04

29-Oct-04

05-Nov-04

12-Nov-04

19-Nov-04

26-Nov-04

Observed Base Low-Eddy High-Eddy

1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493

1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
R-102

Feature CD6

1554
R-103

Feature CD6

1555
1556
1557
1558
R-303

FEATURE CD7

1559
R-304

FEATURE CD7

1560
1561

1563

1565
1566
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)



	
 

 
 
  	
 
 
	 	  
	 

 



  

 
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1567
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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1568
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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marsh berm measures)

 

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1980199020002010202020302040205020602070

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1569
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

A

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1570
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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2.2 Predicting Net Wetland Benefits of Marsh Nourishment Measures (e.g. measure

CD7)

 

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1000

2000

3000

4000

5000

6000

2000 2020 2040 2060 2080 2100 2120 2140 2160 2180 2200

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Acres

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0

200

400

600

800

1000

Net Benefit Acres

FWOP

FWP

FWOP w/med SLR

FWP w/med SLR

benefits

benefits w/ med SLR

1571
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

?

	 
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1572
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

*6

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2.3 Predicting Net Wetland Benefits of Shoreline Protection Measures (e.g. measure

WO2)

 

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Marsh Nourishment

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

1980 2000 2020 2040 2060 2080 2100 2120 2140 2160 2180 2200

Year

Acres

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

Net Benefit Acres

FWOP

FWP

FWOP w/med SLR

FWP w/ med SLR

Benefits

Benefits w/med SLR

1573
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

**

	 
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1574
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

*0

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1575
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

*2

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1576
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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1577
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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Scenario (cfs) (cfs) (cfs) Scenario Formula

A -200 -100 0 =IF(AND(FWP<=0,FWOP<=0),0, below if statement)

B -200 100 -100 =IF(AND(FWP<0,FWOP>=0),FWOP*(-1), below if statement)

C 200 -100 200 =IF(AND(FWP>0,FWOP<=0),FWP, below if statement)

D 200 100 100 =IF(AND(FWP>=0,FWOP>=0),FWP-FWOP,"")

Net

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B -200 100 -200 =IF(AND(FWP>=0,FWOP>=0),FWP,"")*(-1)

C 200 -100 100 =IF(AND(FWP>=0,FWOP<0),FWOP*(-1), below if statement)*(-1)

D 200 100 0 =IF(AND(FWP>=0,FWOP>=0),0, below if statement)*(-1)

-100

0

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(cfs)

Positive Flow Freshwater Introduction Scenarios

Negative Flow Freshwater Introduction Scenarios

100

200

1578
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

*4

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1579
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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1580
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Annex 1

FWS Comments on WVA Model Certification

FWS Comments on WVA Model Certification Relative to the LCA Convey

Atchafalaya River Water to Northern Terrebonne Marshes (ARTM) Project

February 10, 2010

8
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Comment #1: Starting the SI curves for all variables at 0.1 is problematic because even

habitat with no ecological value appears to have some ecological value.

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Comment #2: Justification for assigning variable weights needs to be provided.

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Comment #3: The number of target years should be increased to improve the predictive

ability of the models given that changes are often non-linear.

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1581
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)


 	 


 
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Comment #4: In the spreadsheet for the marsh models, open water and emergent marsh

AAHUs are incorrectly combined and should be added rather than taking the weighted

arithmetic mean (model issue).

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Comment #6: Sea level is an important phenomenon and relative sea level rise and

climate change should be included in the models

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Comment # 10: For some model variables, policy decisions appear to supersede what is

known about the ecology and hydrology of the relationships.

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Comment #11: The spreadsheets for the models as created are likely to lead to errors in

maintenance and use.

1582
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

9+1 	/ 1
   	
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Comment #12: Several inaccuracies were identified in the model spreadsheets that

should be corrected (spreadsheet issue).

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Comment # 15: The WVA method should be expanded to handle risk and uncertainty in

areas exposed to episodic events.

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Comment # 16: The WVA methodology should be updated, taking into account new

sources of GIS data, LIDAR, and other new data sources, as well as computer simulation

and visualization tools.

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Comment #18: The use of the geometric mean may be more appropriate than the

arithmetic mean to derive some HSIs. Provide scientific basis for the decision to use one

over the other.

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1583
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Comment #20: The geographic boundaries/domain of the models is unclear.

9+1 	/ # +, 	 $
 	 	
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Comment # 21: An explicit statement should be provided regarding the minimum area to

which the models can be applied.

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1584
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Annex 2

SAND2 Model Verification

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1585
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

9
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54,000

59,000

64,000

69,000

74,000

79,000

84,000

89,000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Time (yr)

Marsh Area (ac)

Diversion Begins

Observed

Predicted FWOP

Predicted FWP

1586
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

9
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6,000

7,000

8,000

9,000

10,000

11,000

12,000

13,000

14,000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Time (yr)

Marsh Area (ac)

Diversion Begins

Observed

Predicted FWOP

Predicted FWP

1587
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

9
 : 1L:0 
	 	 
 L	 9
$

 :
	 1	 *??20664!

24,000

24,500

25,000

25,500

26,000

26,500

27,000

27,500

28,000

28,500

29,000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Time (yr)

Marsh Area (ac)

Diversion Begins

Observed

Predicted FWOP

Predicted FWP

1588
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose

Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Annex 3. Quantifying Benefits of Freshwater Flow Diversion to Coastal Marshes:

Theory and Applications.

1589
Quantifying Benefits of Freshwater Flow Diversion to Coastal

Marshes: Theorya and Applicationsb

S. Kyle McKay1, J. Craig Fischenich2, S. Jarrell Smith3, and Ronald Paille4

1

U.S. Army Engineer Research and Development Center (ERDC)

Environmental Laboratory

187 Oglethorpe Ave. Apt. B

Athens, Georgia, 30606

Email: Kyle.McKay@usace.army.mil

2

U.S. Army Engineer Research and Development Center (ERDC)

Environmental Laboratory

3909 Halls Ferry Rd.

Vicksburg, Mississippi, 39180

Email: Craig.J.Fischenich@usace.army.mil

3

U.S. Army Engineer Research and Development Center (ERDC)

Coastal and Hydraulics Laboratory

3909 Halls Ferry Rd.

Vicksburg, Mississippi, 39180

Email: Jarrell.Smith@usace.army.mil

4

U.S. Fish and Wildlife Service

646 Cajundome Boulevard, Suite 400

Lafayette, Louisiana 70506

Email: Ronald_Paille@fws.gov

Keywords: wetland, Louisiana, accretion, uncertainty, organic, inorganic, coastal

restoration, operation,

Abstract

The combination of relative sea level rise and river/marsh disconnection has created a

deficit of available soil and accompanying land loss in a large portion of coastal

Louisiana. The U.S. Congress recently charged the U.S. Army Corps of Engineers, State

of Louisiana, and other federal and local agencies with restoring the coastal wetlands of

Louisiana and Mississippi. Many alternative combinations of restoration measures have

been proposed, and assessment of the advantages and disadvantages of these efforts must

be made to determine the optimal design. One technique being applied for coastal

restoration is the reconnection of rivers to coastal marshes through flow diversions.

a Based on material from McKay, S.K., J.C. Fischenich, and S.J. Smith. (2008). Quantifying Benefits of

Flow Diversion to Coastal Marshes. I: Theory. In draft for submission to Ecological Engineering.

b Based on material from McKay, S.K., J.C. Fischenich, and R. Paille. (2008). Quantifying Benefits of

Flow Diversion to Coastal Marshes. II: Application to Louisiana Coastal Protection and Restoration. In

draft for submission to Ecological Engineering.

1

1590
Freshwater flow diversions offer significant nutrient and sediment inputs to marshes that

induce both organic and inorganic accumulation of soil. Boustany (2007) presented a

screening level model for assessing both the nutrient and sediment benefits of flow

diversion over long time scales. This paper has presented the adaptation of Boustanys

(2007) model to include daily variation in sediment processes in order to optimize

diversion structure design and operation. The model was verified using an existing

diversion to prove the ability of the model to track land evolution associated with flow

diversion. This paper also demonstrates the application of the model to diversion

operational and structural optimization.

Introduction

In the fall of 2005, Hurricanes Katrina and Rita awakened the United States public to the

natural protection that coastal wetlands provide in reducing of the effects of hurricanes on

coastal communities. In response to these catastrophic events, the U.S. Congress directed

the U.S. Army Corps of Engineers (USACE) to conduct a comprehensive hurricane

protection analysis and designto develop and present a full range of flood control,

coastal restoration, and hurricane protection measures (USACE, 2006). This paper

focuses on interagency efforts to assess and weigh benefits of coastal restoration via

freshwater flow diversion. The paper will focus on the development and adaptation of a

screening level model to quantify the benefits of flow diversion to coastal marshes and

will describe the assessment of various diversion operational and structural scenarios.

Coastal Marsh Accretion and Flow Diversion

The tidal marshes of coastal Louisiana are receding at alarming rates as high as 115

km2

/yr (Barras et al., 1994). Submergence of these valuable ecological assets (Figure 1)

was once counteracted by vertical accretion due to the addition of freshwater, nutrient,

and mineral inputs from riverine environments; however, eustatic sea level rise (ESLR)

and basin subsidence now exceed the current rate of vertical accretion, and coastal

marshes have been disconnected from their freshwater and sediment sources, distributary

channels of the Mississippi and Atchafalya Rivers. ESLR has been attributed to global

increase in ocean volume and has been estimated as 1.0-2.4 mm/yr (Church et al., 2001).

Subsidence of the Mississippi delta has been attributed to multiple factors, namely:

regional isostasy, faulting, sediment consolidation, and soil dewatering (Dokka et al.,

2006). Previous researchers identified other potential sources of subsidence as

groundwater and petroleum extraction (Morton et al., 2002); however, Dokka et al.

(2006) renounce these hypotheses as unlikely due to the relative lack of groundwater

extraction from the highly saltwater intruded groundwater table of most of southern

Louisiana and the lack of coincidence between petroleum extraction and subsidence. The

synergy of ESLR and basin subsidence has created an apparent local change in sea level

known as Relative Sea Level Rise (RSLR) that has been measured in the Mississippi

Delta at rates as high as 10 mm/yr (Snedden et al., 2007).

In addition to RSLR, the disconnection of coastal marshes from their sediment and

nutrient source is equally disconcerting. Over geologic time scales, large-scale delta lobe

switching has lead to alternating episodes of delta building and redistribution of sediment

2

1591
and nutrients throughout the coastal plain (Coleman, 1988; Coleman et al., 1998);

however, in the last two centuries, the Mississippi River has been controlled by levees

and other structures in order to maintain a consistent navigation channel for commerce

and protect infrastructure against floods (Coleman et al., 1998; Parker et al., 2006).

Presently, much of the sediment and nutrient load of the Mississippi River is discharged

directly into the northern Gulf of Mexico through the birdsfoot delta, providing little

benefit to protective delta building and contributing to an increasing zone of hypoxia near

the river mouth (Mitsch et al., 2001). In addition to problems associated with fate of

river sediment and nutrients, this disconnection starves coastal wetlands of historic

nutrient and sediment inputs necessary for marsh sustainment. Although the relative

importance of this multitude of factors has yet to be rigorously quantified throughout the

Louisiana coastal plain, the combination of RSLR and river/marsh disconnection has led

to high land loss rates and conversion of many freshwater marshes to shallow saltwater

bays.

In recent years, freshwater flow diversions from river sources to coastal marshes have

been offered as a tool for combating RSLR and disconnection of rivers and wetlands. In

these diversions, river water is released into marshes to simulate flooding of a river onto

its floodplain and increase hydrologic connectivity. Potential benefits have been

observed from pulsing diversion discharges to simulate natural flood regimes (Day et al.,

2003; Reyes et al., 2003; Snedden et al., 2007). Many studies have also shown that flow

diversion is a plausible remedy to reconnect rivers to tidal marshes and deltas and induce

organic and inorganic deposition (Parker et al., 2006; Snedden et al., 2007). An ancillary

benefit of these flow diversions is potentially reduction of the nutrient loading to the Gulf

of Mexico with associated reduction in the hypoxic zone (Lane et al., 1999; Mitsch et al.,

2001).

Vertical accretion of marshes has been identified as highly dependent upon both

inorganic and organic accumulation (Figure 2; Delaune et al., 1981; Nyman et al., 1993;

Day et al., 1995; Reed, 1995; Foote and Reynolds, 1997; Nyman et al., 2006; Morris,

2007). Often accretion is only accounted for through sedimentation (e.g. Parker et al.,

2006); however locations have been identified that depend more upon organic inputs than

sediment inputs (Nyman et al., 2006). The characteristics of the receiving marsh and

associated hydrologic connectivity are likely to influence whether inorganic or organic

inputs control (Boustany, 2007). For instance, if a region is initially unvegetated,

sediment inputs will be necessary to establish a soil platform for dense vegetative growth;

however, once vegetation is well established, the vegetative inputs are likely to dominate

while at the same time inducing higher retention of sediment in the process. This

complex feedback system necessitates the inclusion of both inorganic (sediment) and

organic (vegetative) inputs to any calculation of vertical accretion (Reed, 1995).

Vegetative accumulation in coastal marshes involves a delicate balance of above and

belowground plant productivity (Gosselink, 1984; Edwards and Mills, 2005), salinity

(Visser et al., 2004), nutrient availability (Delaune et al., 2005), flood frequency (Nyman

et al., 2006), vegetation type (Gosselink, 1984), and seasonality (Visser et al., 2004),

among other factors. Freshwater reintroduction has been shown to increase nutrient

3

1592
inputs to coastal marshes (Lane et al., 1999) and stimulate growth in these ecosystems

(Cardoch et al., 2002), further causing vegetative inputs to contribute to accretion. In

coastal Louisiana most marshes are nutrient limited (Nyman et al., 1990; Delaune et al.,

2005), so the introduction of limiting nutrients such as nitrogen and phosphorous from

flow diversion is a topic of great importance when considering flow diversion alternatives

and benefits (Lane et al., 1999; Hyfield, 2004; Hyfield, 2008); however, excessive

nutrient loading to coastal wetlands could potentially induce harmful water quality effects

such as eutrophication (Delaune et al., 2005) or stimulation of invasive plant species

(Carter and Bernard, 2007), so diversion of flow to coastal wetlands must be carefully

balanced and planned.

The accretion of sediment on coastal marshes and deltas has also been studied

extensively (Stumpf, 1983; Wang, 1997; Rybczyk and Cahoon, 2002; Reyes et al., 2003;

Parker et al., 2006; Snedden et al., 2007). Relevant sedimentation processes have been

identified as sediment loading from floods/diversions (Reed, 1995; Parker et al., 2006),

sediment settling properties (Stumpf, 1983; Soulsby, 1997; Winterwerp and van

Kesteren, 2004), tidal erosion (Stumpf, 1983; Wang et al., 1997), wind and storm induced

erosion and deposition (Wang, 1997), sediment export through canals and bayous (Wang,

1997; Baustian and Turner, 2006), and vegetation induced settling (Gleason et al., 1979;

Stumpf, 1983; Reed, 1995; Leonard and Luther, 1995).

Although flow diversions have proved useful for combating coastal land loss, the

optimization of flow diversion locations and operation has been difficult due to the

complexity in data needs of a coupled ecological and hydrodynamic model (Reyes et al.,

2003; Delaune et al., 2003; Snedden et al., 2007). These complexities encourage the

development of a simple, screening-level model that includes the effects of vegetation

and sediment dynamics and allows for straightforward examination and optimization of

flow diversion feasibility and operational benefits.

Boustany (2007) Landscape Evolution Model

Boustany (2007) developed a composite nutrient and sediment model to assess the

feasibility of flow diversions and screen diversion alternatives under the Coastal Wetland

Planning, Protection, and Restoration Act (CWPPRA; Boustany, Personal

Communication). This model, herein referred to as the Boustany Model (BM), presents

all benefits of flow diversion in terms of marsh area by assuming all nutrient and

sediment benefits additive to the existing area and land change rate:

1 ii  nut i  AAAA sed

Equation 1

Where Ai is the marsh area at time i, nut is the fractional change in land area due to

RSLR and river-marsh disconnection (value may be positive or negative) that has been

adjusted to account for the benefits associated with nutrient addition, and Ased is the area

benefit of sediment addition.

The BM was developed to compare long term relative benefits of many flow diversion

locations and was implemented with an annual time step to provide quick estimates of the

potential benefits of diversions. The BM is sufficient for quick estimation of flow

4

1593
diversion benefits and initial screening of alternatives, but the LACPR program required

greater temporal resolution in order to assess not only the relative benefits of diversion

locations, but also the effects of diversion structure type, diversion operational regimes,

and hydrologic variability. Ideally a detailed two- or three-dimensional model coupling

nutrient and sediment processes would be used to account for the complex mechanisms

governing coastal marsh accretion (Reyes et al., 2000; Dortch et al., 2007); however, the

vast number of alternatives and short time scale of the LACPR report to Congress

precluded development of such models for every alternative and marsh. As such, the BM

was adapted to include processes deemed most critical to LACPR alternatives analysis.

The following sections provide further details of the nutrient and sediment models

implemented in the landscape evolution calculations, but the two major adaptations of the

BM were:

 High temporal variability in sediment processes encouraged the refinement of the

temporal resolution of the sediment model to include daily impacts of the

diversion on the marsh.

 In order to maintain model simplicity, the BM required estimation of a number of

parameters to account for nutrient and sediment processes (e.g. sediment retention

and average annual suspended sediment concentration). The adaptation of the

model has also included the calculation of many of these inputs in order to

account for temporal variance, reduce data requirements, and minimize potential

input errors.

Nutrient Benefits

Nutrient addition to coastal marshes has proven to be a source of vegetation stimulation

and strengthening and biomass creation (Deegan et al., 2007). Boustany (2007) proposes

a model that accounts for the ability of nutrients to stimulate vegetation to better resist

erosional processes. This model determines the percent of the vegetated area that is

strengthened from nutrient addition. This parameter is found by examining the annual

nutrient requirements of the marsh relative to the nutrients loaded to the marsh.

The nutrients required by the marsh for vegetative growth are assumed to be the mass of

the nutrients held in plant biomass. This quantity may be assessed by examining the rate

of biomass production (annual primary productivity, Pr) and the percent of biomass

containing these nutrients (). Since most Louisiana coastal marshes are nitrogen or

phosphorous limited, Boustany proposes that the total concentration of nitrogen and

phosphorous (TNP) be used to account for nutrient benefits.

LRreq Pr TNP  

Equation 2

Where LRreq is the marsh required nutrient loading rate [ML-2T-1], Pr is primary

productivity [ML-2T-1], and TNP is the percent of plant biomass containing nitrogen and

phosphorous [1].

The nutrient loading rate of the diversion to plant biomass, LRdiv, may be calculated from

the volumetric discharge of water to the marsh from the diversion, Qdiv [L3T-1], the

5

1594
concentration of nutrients in the source water, Csource [ML-3], the retention rate of

nutrients in plant biomass, Rnut [1], and the vegetated marsh area, Aveg [L2].

nut

veg

div source

div R

A

CQ LR 

Equation 3

In addition to nutrient loading from the diversion, there is ambient nutrient loading to the

marsh from other ongoing processes (e.g. atmospheric deposition, stormwater runoff,

current plant decomposition, denitrification, etc.). These processes will be accounted for

by a loading rate for background sources, LRbackground. The net loading of nutrients to the

marsh, LRnet, is therefore the sum of the background and diversion loading rates.

net div  LRLRLR background

Equation 4

From knowledge of the loading rates applied, LRnet, and required, LRreq, one may obtain

the fraction of wetlands sustained by nutrient addition, Es.

req

net

s LR

LR E 

Equation 5

In this model, nutrients are assumed to be unable to freely construct land; however, they

can reduce the loss rate by strengthening vegetated areas against erosion. This

assumption produces conservative estimates of the organically-induced benefits of the

diversion. For instance, in an environment with a low land loss rate, according to the

model, the diversion could potentially reduce the land loss to zero; however, no land gain

would be associated with organic inputs. The percentage of wetland sustained by nutrient

addition serves as a reduction ratio to the land loss rate in the form of Equation 6.

 

	








 
  0 11 1

s

s s

nut ForE

 ForEE



Equation 6

Where  is the land change rate prior to the diversion and nut is the nutrient adjusted land

change rate.

Sediment Benefits

The accumulation of diverted sediments is determined by a sediment budgeting model

utilizing the input concentration of sediment from the source water and calculated

hydrodynamics of the system to determine the quantity of diverted sediment retained in

the marsh. As previously specified, the BM implemented sedimentation calculations on

an annual timescale, and while this assumption is reasonable for preliminary screening of

alternatives, further refinement is necessary for more detailed analyses of flow diversion

benefits. The sediment model implemented herein relies on calculation of sediment

inputs and sediment settling theory on a daily timescale over a single representative year

and reapplies that year throughout the proposed project life cycle.

Sediment Input

In order to minimize costs and maximize benefits of flow diversion in coastal Louisiana,

diversion structures often withdraw water from one of the regions major rivers (e.g.

6

1595
Mississippi, Atchafalya, Calcasieu). These rivers are located throughout the coastal

plain, carry large water and sediment loads, and serve as a virtually infinite source of

diversion resources.

River discharge and suspended sediment concentration have often been shown to be

positively correlated (Mossa, 1996; Snedden et al., 2007). The relationship between

discharge and sediment load may be determined by analytical and partially analytical

models (e.g. Meyer-Peter Muller, Einstein, Yang; Richardson et al., 2001) or by

empirical models for a given set of observed discharge and sediment concentration values

(Mossa, 1996; Snedden et al., 2007). In coastal Louisiana, there exists enough recorded

sediment discharge data to generate empirical models of sediment concentration for some

of the major rivers of the region. For this analysis, a power function was found to

provide enough resolution in sediment concentration variation (Equation 7). Table 1

presents a number of sediment ratings of this form for coastal Louisiana.

2

, 1

a

s river  QaQ river

Equation 7

Where Qs,river is sediment load (ton/da), Qriver is river discharge (cfs), a1 is a dimensional

coefficient, and a2 is a dimensionless coefficient. From this sediment rating, flowaveraged suspended sediment concentration of the river, Criver, may be

calculated 



 



  river

s river

river Q

Q C , and transformed to the desired units.

Regardless of the model defining this relationship, the sediment concentration has been

shown to be highly dependent upon discharge; therefore, in order to capture the temporal

variance in sediment discharge through a diversion, the sediment concentration must vary

with river discharge at an appropriate time scale (Snedden et al., 2007). For the purposes

of this analysis, daily variation in discharge provides sufficient temporal resolution for

accurate calculation of sediment loading to marshes by diversions.

One of the purposes for adapting the BM is the desire to examine relative diversion

structure operation. In order to do this, daily estimates of diversion discharge are also

required. These daily diversion discharges, Qdiv, are combined with the daily predictions

of river suspended sediment concentration, Criver, to determine the mass loading rate of

sediment to the marsh, Qs,div (Equation 8). This increase in temporal resolution allows for

examination of diversion discharge operation such that sediment benefits may be

maximized by coinciding diversion discharges with periods of high river suspended

sediment concentration.

,divs  CQQ riverdiv

Equation 8

Sediment Retention

After sediment laden water has been diverted to a coastal wetland, a portion of the

sediment load is expected to settle from suspension and deposit. Sediment that remains in

suspension is then subject to being transported outside the system boundaries. Sediment

retention defines the fraction of diverted sediments retained within the coastal wetland.

7

1596
Retention is dependent upon system properties such as: wetland geometry, diversion

discharge, tidal velocities (Stumpf, 1983), wind and storm events (Wang, 1997), settling

velocity of diverted sediments (Soulsby, 1997; Winterwerp and van Kesteren, 2004),

vegetation coverage (Stumpf, 1983), and canal-induced sediment import/export (Wang,

1997). The approach taken by Boustany (2007) is to apply retention factors estimated for

other sites (e.g. Wax Lake Outlet) or allow the analyst to choose a retention factor based

on knowledge of the receiving area and best professional judgment. Building upon the

suggestion of Stumpf (1983), an alternative to this approach is to use a simple calculation

which includes effects of wetland geometry, sediment properties, and flow

hydrodynamics at the site. The effects of vegetation and channels are ignored in this

analysis in order to maintain model simplicity; however, vegetation would likely increase

roughness, reduce turbulence, and induce greater sediment deposition leading to

conservatively low estimates of sediment retention, while the influence of channels may

serve as pathways to sediment export and thus produce non-conservatively high estimates

of sediment retention.

Consider suspended sediments in a water body. The time required for a given particle to

settle from the water surface to the bed is given as:

Ws eff

H T

,



Equation 9

Where T is the time required for sediment to completely settle, H is the local depth, and

Ws,eff is the effective settling velocity of a specific sediment class.

As the particle settles, it is also transported by tidal and diversion currents, so the distance

traveled by the particle is:

s eff

div div W

H UTUX

,



Equation 10

Where U is the diversion induced mean velocity. As the averaging timescale of the

model is greater than the tidal period and net tidal flow is zero, Equation 10 neglects the

influence of tidal velocities, and the net displacement of water within the marsh is

described by the diversion flow.

For this analysis the wetland is assumed to have rectangular planform and cross-sectional

geometries described by the average length (L), width (B), and depth (H). The fraction of

sediment retained in the wetland then becomes a function of wetland length relative to

transport distance prior to full deposition of the sediment fraction in question (Stumpf,

1983). If all diverted sediment is retained within the system, the retention factor is 1.

Since this analysis takes a macroscopic view of the total sediment retained in the system

and location of deposit is not considered, the retention factor becomes 1 if the length of

the wetland is greater than the transport length, and the retention of a given sediment

particle class, Rj, may be expressed as:





 



  min 1, X

L Rj

8

1597
Equation 11

Due to variation in fall velocity with sediment size, coarse particles may be retained

while fines are flushed from the system; therefore, the combined retention of the entire

grain size distribution must be made. Retention over all sediment classes may be

expressed as:

T   jj fRR

Equation 12

Where RT is the combined total retention factor and fj is the mass fraction associated with

each sediment class.

Fall Velocity

A key element of the sediment budgeting model presented is the calculation of the

effective fall velocity of a given sediment size class, which is a function of the fall

velocity of that sediment in a static body of water, Ws, and the turbulence of the flow.

Fall velocity of sediment is dependent upon both sediment properties (shape, size,

density, concentration, ability to flocculate) and fluid properties (viscosity, density,

temperature, salinity). In the natural environment, turbulence is generated by flow over

the sediment bed. The presence of turbulence acts to vertically mix suspended sediments,

which reduces the effective settling velocity of suspended particles. The steady-state

vertical flux balance at a point in the water column is given by:

0

dz

dC s KCW z

Equation 13

Where C is the suspended sediment concentration, Kz is the vertical diffusivity, and z is

the vertical distance from the bed.

For the purposes of this tool to estimate retention, it is convenient to combine the terms in

Equation 13 to define an effective settling velocity (Equation 14).

dz

dC s,eff s  KCWCW z

Equation 14

Vertical diffusivity varies with turbulent intensity and height above the bed. Rouse

proposes that diffusivity varies parabolically with height above the bed in the form

(Richardson et al., 2001):





 



  H

z z  * zuK 1

Equation 15

Where  is the von Karman constant (~0.4) and u* is the total friction velocity (a measure

of turbulent intensity).

Given the sediment flux balance in Equation 13, the vertical concentration profile is: b

a

a

a zH

zH

z

z CC





















 

Equation 16

9

1598
Where b is the Rouse parameter 



 



  u*

W b s

 and za is a reference height above the bed

with a known sediment condition, Ca.

The turbulent shear velocity is estimated from the depth-averaged velocity by the

logarithmic boundary layer (law of the wall) (Kundu, 1990).



















 

0

*

3 ln z

H

U u 

Equation 17

Where U is the daily mean wetland velocity with both tidal and diversion related

components and z0 is the hydraulic roughness length.

For the diurnal tidal cycle of coastal Louisiana, the tide is assumed to have approximately

sinusoidal periodicity. The mean instantaneous wetland velocity can then be determined

by considering both tidal and diversion components (Figure 3).

max, sin max,tide sin divi div tide U

HB

Q  UUU 

Equation 18

Where Ui is the instantaneous mean velocity with tidal and diversion components and

Umax,tide is the maximum tidal velocity (or tidal amplitude), and  is tide phase.

For the use in the flow diversion model, the velocity is integrated over the tidal cycle (0

to 2) to obtain the daily mean velocity, U.

         201 max, 2 1 0 2 cos 2cos cos 2

1      UU div  U tide   

Equation 19

Where 0 is the tide phase at zero up-crossing 



 



 



 



  

tide

div

U

U

max,

1

0  sin , 1 is the tide

phase at zero down-crossing   1   0 , and 2 is the completed tidal

phase    02  2 (Figure 3).

In order to estimate the shear velocity, the hydraulic roughness must also be estimated

from local sediment grain size, form roughness, and vegetative coverage. In this

analysis, a lumped parameter accounting for both grain size and form roughness is

implemented based on marsh surface character (Table 2). Vegetative roughness is

incredibly important in coastal marshes where emergent plants are encountered

throughout the marsh, and although basing this parameter on bed material ignores the

effects of vegetation, this will provide an estimate of sediment settling in open water and

will therefore provide conservative estimates of settling in vegetated or partially

vegetated marsh.

10

1599
Combining Equation 13  Equation 17, one may obtain an expression for the effective

settling velocity of sediment in coastal marshes.

  















 



 





 













  

 

2

1

,

zH

H

zH

z

z

zH bKWW

b b

a

a

effs zs

Equation 20

For incorporation into the flow diversion model, vertical mixing has been computed at a

height above the bed equal to 1/10 of water depth   10 z  H and za is approximated as

1/100 of the depth   100 z H a  . These values provide an estimate of the settling velocity

of particles very near the bed that are assumed to settle. Insertion of these relations into

Equation 20 yields:

  



 



 



 



 





H

bKWW

b

b

effs zs

81.0

9

1 99

1

,

Equation 21

Where K Hu z *  009.0  .

Net Sediment Benefit

By accounting for sediment loading to the marsh and sediment retention within the

marsh, the mass loading rate of sediment retained in the marsh may be determined by:

,  , RQQ Tdivsnets

Equation 22

Where Qs,net is the net mass loading rate of sediment to the marsh.

This loading rate may then be used to calculate the net aerial sediment benefit due to flow

diversion, Ased, for a given time period.

bd

nets

sed H

dtQ A



, 

Equation 23

Where dt is the time step (da) and bd is the average bulk density of the receiving area.

Bulk density in coastal marshes varies significantly with depth due to sediment

consolidation. For our analysis, we assumed that the bulk density was a depth averaged

value based on the depth of marsh being filled with sediment (i.e. flow depth, H). Bulk

density profiles were obtained from literature (Nyman et al., 1990; Nyman et al., 1993;

Delaune et al., 2003) and available data (Michael Channel, personal communication).

Application: Caernarvon Diversion and Breton Sound Estuary

In order to verify the ability of the model to account for landscape evolution due to flow

diversion, the model was applied to an existing diversion structure and marsh, the

Caernarvon Diversion to Upper Breton Sound Estuary (Figure 4). The Caernarvon

Diversion is located on the east bank of the Mississippi River at river mile 81.5 (131.2

km) (approximately 12.5 river miles (20.1 km) downstream of New Orleans) and

11

1600
discharges Mississippi River water into Breton Sound through five 15-ft (4.57-m) box

culverts with vertical lift gates (Lane et al., 1999; Snedden et al., 2007). The diversion

was constructed between 1988 and 1991 and opened for operation in August of 1991 with

goals of reducing the salinity in Breton Sound for commercial shell fisheries. An

ancillary benefit of the diversion has been sediment and nutrient loading to the marsh and

corresponding reduction in land loss (Snedden et al., 2007).

Upper Breton Sound is approximately 231 mi2 (599 km2

) in area with a length of 18.8 mi

(30.2 km) and a width of 12.3 mi (19.8 km). This estuary was historically an

intermediate marsh, but due to RSLR and river/marsh disconnection, marsh salinity

elevated to brackish conditions before the diversion became operational (Carter and

Bernard, 2007). The current marsh is dominated by brackish species (e.g. S. patens) near

the diversion and saline marsh species (e.g. S. alterniflora) far from the diversion

(Snedden et al., 2007).

Breton Sound is hydrologically isolated from surrounding marshes by levees on both the

eastern and western borders; therefore accounting for inflows and outflows to the marsh

is relatively straightforward with water budgets for Upper Breton Sound revealing major

hydrologic processes to be precipitation, evaporation, and freshwater diversion.

Groundwater and stormwater inflows have been shown to be relatively small compared to

precipitation and diversion (Hyfield, 2004).

In order to maximize the retention time of diverted water and induce desirable sediment

settling and nutrient uptake, the State of Louisiana has initiated outfall management for

the Caernarvon Diversion. Management actions have included restoration and

backfilling of man-made canals, installation of control structures throughout the marsh

(Carter and Bernard, 2007), and operational adjustment to test theories of marsh

sedimentation processes (Snedden et al., 2007).

Snedden et al. (2007) have shown that a large majority (nearly 99%) of Caernarvons

discharge flows downmarsh through two major flow routes for low discharges. These

authors indicate that below 3500 cfs, the diverted waters remain almost entirely in these

canals. When diversion discharge exceeds this threshold value, diverted waters appear to

exceed canal banks and flow over the marsh as sheet flow (Snedden et al., 2007). This

indicates that large pulses of discharge may be more effective in distributing sediments

throughout the estuary. These authors also applied a local river sediment rating based on

near-surface suspended sediment concentrations of the Mississippi River approximately 5

mi (8 km) downstream of the Caernarvon structure at Belle Chase, Louisiana. By

examining sediment loading rates through the diversion, these authors concluded that

pulsing of discharges in phase with high river sediment concentrations not only induces

sheet flow over the marsh, but also has the ability to load much greater quantities of

sediment to the marsh (Snedden et al., 2007).

The Caernarvon Diversion provides an excellent test case for the model developed herein

due to the variable discharge inputs and extensive knowledge of current system

processes. Table 3 presents the inputs to the model for the Caernarvon Diversion and

12

1601
Breton Sound. Many of these inputs have a significant amount of variability and have

been presented with standard deviations in order to provide the reader with a scale of

parameter uncertainty. When data was not available, parameters and ranges were

estimated by best professional judgment. Since many of the input parameters contain a

significant amount of uncertainty and forecasting land evolution in such a complex

system is difficult, model uncertainty has been characterized by a Monte Carlo risk

analysis. In this analysis, parameter uncertainty was estimated and assumed normal about

the mean. Random errors were then introduced in each parameter for 10,000

calculations. Model results were computed with each set of randomly induced errors, and

the range of area predictions was analyzed to determine 90% confidence intervals.

In order to apply the model to Breton Sound, the diversion and river hydrographs must be

estimated to indicate marsh nutrient and sediment availability. The river hydrograph may

be estimated by using a representative water year or by averaging flows for many years

and determining mean daily discharges over a period of record. The diversion

hydrograph may be estimated by applying historic operational records, assuming an input

hydrograph, testing various operational theories (e.g. pulses timed with river discharge),

or linking the discharge to the diversion structure type (e.g. diversion discharge

dependence upon river stage using a weir equation). A sample representative diversion

and river hydrograph are displayed (Figure 5) for operation of the Caernarvon structure in

1994. Both the diversion and river hydrographs for this year output very near average

annual discharge volumes and the peak magnitudes of the hydrographs were well

represented; therefore, for this analysis, the diversion and river hydrographs were

assumed to be that of the 1994 calendar year for each year of the simulation.

Figure 6 presents the evolution of land area within Upper Breton Sound from before the

diversion was opened (1 November 1990) until the end of 2006 (31 December 2006).

This figure shows the observed values of marsh area along with estimates by the current

model with associated parameter uncertainty alongside the Boustany Model. The

estimated future without project (FWOP) is presented to provide the reader with the

magnitude of marsh area benefit the Caernarvon Diversion is providing Breton Sound.

Vertical lines indicate the beginning of diversion operation and hurricanes making

landfall in Louisiana. It is clear that hurricanes create significant perturbations to the

system; however, hurricanes may provide both import and export to a given marsh

depending upon the location of landfall and are, for the purpose of this screening level

model, assumed to create no net import or export of sediment over a long planning

horizon.

In addition to model verification at Caernarvon, readers may be interested in the benefits

provided by nutrient and sediment components separately; therefore Figure 7 presents the

model predictions with nutrient only and sediment only scenarios for the Caernarvon

Diversion application.

Optimization of Implemented Diversion

The focus of LACPR has been the analysis of alternatives and the decision support

framework associated with choosing diversion sites and quantities. The land evolution

13

1602
model has been applied as tool for assisting in this framework and has provided relative

benefits of various flow diversion sites and scenarios. The utility of the tool, however,

has not yet been fully exploited. Following the narrowing of alternatives, the land

evolution model may then be used in the initial optimization of the selected diversions by

examining different operational and structural scenarios. This type of analysis has not yet

been conducted for each of the alternatives of the LACPR, but this section provides a

sample of how these analyses might be conducted for a given diversion site. The model

will be applied to an existing diversion (Caernarvon) to assess the land gain benefits of

six operational and five structural scenarios with near equal annual discharge volumes.

As previously stated, the Caernarvon Diversion discharges Mississippi River water to

Upper Breton Sound through five 15 ft box culverts with vertical lift gates which can be

used to control diversion discharges to the marsh. For this analysis the diversion is

merely used to demonstrate the ability of the land evolution model to provide relative

benefits of different operational and structural conditions. Table 3 provides the model

inputs used for these optimization exercises. For these analyses, the 1994 Mississippi

River hydrograph was found to be representative of the average annual discharge volume,

peak magnitude, and seasonality of flow in the river and has been used throughout the

duration of the model simulations in these exercises.

Operational Optimization of Gate Structures

The continuous hydrographic inputs of the model provide a tool for optimizing gate-type

diversion operation to obtain the greatest land evolution benefits. In this section, the

model will be applied to demonstrate the operational benefits for the six approximately

equal-volume discharge scenarios that follow (Figure 8). These annual hydrographs were

chosen based on previous research indicating that pulsing and timing of diversions may

be critical to land evolution (Day et al., 2003; Snedden et al., 2007).

1. Historic operation based on 2003 operational conditions (a pulsed diversion

year with a large portion of the annual sediment load derived from two twoweek pulses)

2. Simulated operation with a large pulse of one-month duration timed in phase

with high river sediment discharges

3. Simulated operation with a large pulse of one-month duration timed out of

phase with high river sediment discharges

4. Simulated operation with a small pulse of six-month duration timed in phase

with high river sediment discharges

5. Simulated operation with a small pulse of six-month duration timed out of

phase with high river sediment discharges

6. Constant diversion discharge

Each of the annual hydrographs was input to the model, and land evolution estimates

were made for a 50 year time period starting at the arbitrary starting date of January 1,

2001 (Figure 9). These results indicate that, for the inputs considered, the magnitude and

timing of the diversion discharges is critical to suppression of the land loss rate.

Therefore, for this hypothetical diversion scenario at Caernarvon, the diversion of flows

14

1603
could be altered to be in phase with high river sediment discharges and should occur from

later winter to early summer (February  June). These periods of high sediment

discharge may not, however, align with other project goals of a given diversion (e.g.

reduction of salinity for maintenance of commercial fisheries). This analysis indicates a

time period over which the greatest land evolution benefits may be obtained, and

diversion operation may be optimized within that timeframe to include multiple project

goals.

Structure Selection

Not only will operational considerations impact diversion benefits, but structure type will

also have a drastic impact on the selection and operation of a given diversion. For

instance, a gate-type structure (such as the one at Caernarvon) may be controlled to

achieve the desired water and sediment discharges, but the cost and maintenance may be

high. Whereas a broad-crested weir may have low cost, but control of diversion

discharges is relatively minimal. A siphon is a third common diversion structure that

may require significant maintenance and operational effort, but the suspended sediment

concentration of the diverted water may be higher and the size gradation of the sediment

diverted may be significantly larger inducing more land gain on both accounts. This

section will demonstrate the ability of the model to assess land evolution by applying the

model to the Caernarvon Diversion for the following five hypothetical structural

scenarios:

1. Gate structure with pulsed operation based on the 2003 hydrograph

2. 100-ft wide broad-crested weir

3. 200-ft wide broad-crested weir structure

4. 1  15 ft siphon with a single short duration (113 day) discharge event

5. 1  6 ft siphon with continuous operation throughout the year

The weir structures have been assumed to behave as theoretical broad-crested weirs

(Equation 24) and the discharge was determined based on the Mississippi River stage for

the representative hydrograph (1994). The weir elevations were adjusted to produce

annual discharge volumes approximately equal to the average annual diversion discharge

volume from 1991-2006.

  2/3

div weirweir river weir   zzBCQ

Equation 24

Where Cweir is a weir coefficient (~4.37 ft0.5/s), BB

weir is the width of the weir (ft), zriver is

the elevation of the river for a given flow rate (ft), zweir is the elevation of the weir (ft)

(White, 2003).

In order to calculate the discharge of the diversion by siphoning, Bernoullis equation

was implemented (Equation 25). Frictional losses in the pipe were assumed negligible

due to the qualitative nature of this analysis. As with the weir, the marsh elevation was

optimized to produce annual discharge volumes approximately equal to the average

annual diversion discharge volume from 1991-2006. Figure 10 presents diversion

discharge hydrographs for the five scenarios considered.

15

1604
  













    4

2

2 d AVQ zzg div siphon siphon river marsh



Equation 25

Where zmarsh is the elevation of the marsh and d is the pipe diameter.

The land evolution model was applied using these annual diversion hydrographs and the

parameters from the Caernarvon Diversion (Table 3). The only alteration of the

Caernarvon model inputs was the sediment rating curve and size fraction applied to the

siphon calculations. A weir or gate structure diverts surface waters of the Mississippi

River to the marsh, and the Belle Chase surface sediment rating presented in Table 1 was

determined as such (Snedden et al., 2007), but a siphon could draw water from lower in

the water column, producing a larger sediment concentration and a more coarse sediment

size fraction. As such, the total sediment rating at Belle Chase was applied with an

assumed size fraction distribution based on the observed fraction of silt and clay (fsand =

0.12, fsilt = 0.44, fclay = 0.44, ffloc = 0.3).

As evident by the land evolution calculations (Figure 11), the benefits of flow diversion

are extremely sensitive to the size fraction and concentration of the river water diverted.

Therefore, the choice of structure type from a land evolution perspective is

overwhelmingly in favor of siphons which divert higher concentrations of coarser

sediment. However, logistical difficulties associated with operation and maintenance of a

siphon (e.g. maintaining head differential, priming the siphon, air intrusion) may

eliminate this structure type from consideration in many instances. It is also important to

note that the results presented herein likely offer overly optimistic benefits of siphon

structures due to the exclusion of friction in the siphon and the use of the total suspended

sediment rating at Belle Chase. Although the siphon will be able to draw water from

lower in the Mississippi River water column than a gate or weir, in order to maintain

appropriate pressure differential for flow to the marsh, the siphon inlet will likely be

required to draw in the upper half of the water column where suspended sediment

concentrations are lower. The land evolution benefits of a siphon may also be

overshadowed by other project objectives which may be detrimentally impacted by high

turbidity or suspended sediment concentrations, such as fisheries production and marsh

vegetation stimulation.

Summary of Diversion Optimization

The purpose of this exercise was not to identify an operational condition or structural

alternative that is ideal for all flow diversions in coastal Louisiana, but was instead to

demonstrate the land evolution models ability to maximize land gain benefits for various

operational and structural alternatives. Land gain (or suppression of land loss) is often

not the only objective in the large-scale, long-term projects of the LACPR, and many

other factors may be included in the selection of a diversion operational or structural

scheme, some of which include:

 Cost of diversion with both structural and operation/maintenance components

 Desire to control diversion releases

 Commercial fisheries impacts

 Public recreational land use patterns

16

1605
Conclusions

This paper has presented the adaptation of a model for quantifying flow diversion

benefits and demonstrated the models ability to estimate the relative benefits of various

flow diversion locations, structures, and operational regimes; however, the model results

are limited due to the exclusion of a variety of important system processes. Some of the

major assumptions and limitations of the model were:

 Benefits of flow diversion are independent (in reality the benefits are likely nonlinearly coupled due to vegetation inducing sediment deposition and

sedimentation increasing suitable habitat for vegetation)

 Nutrients serve as a reduction in land loss, not a source of land gain benefits

(Deposition of particulate organic matter neglected)

 Spatial uniformity - vegetation, roughness, bulk density, and other parameters are

highly heterogeneous in coastal marshes

 Temporal resolution is only represented intra-annually, not contiuously

 Rectangular wetland geometry

 No vegetative component to settling/roughness

 Organic accumulation is not considered as a function of time even through

biomass production is highly seasonal

 No habitat switching with time

 Canals are not accounted for as a sediment loss mechanism

 Sheetflow was assumed for all diversion flow rates

 No sediment resuspension due to rainfall, tidal flows, waves, or hurricanes

 Uniform distribution of sedimentation.

 Nutrient recycling neglected

Although these assumptions significantly limit the models ability to quantify the benefits

of flow diversion, approximations had to be made due to the time and resource

constraints under which the model was developed. Further refinement of model

processes and algorithms are recommended and should address the above limitations

specifically focusing on the following:

 Temporal distribution of nutrient benefits to account for seasonality and storage

 Nutrients as a source of benefit, not just a source of loss reduction. Refer to the

organic accumulation models of Blum et al. (1978), Mitsch and Reeder (1991),

and Reyes et al. (2000) for examples of organic benefit frameworks

 Nutrient retention calculations inclusive of marsh nutrient cycling processes (e.g.

denitrification, burial)

 Division of nutrients  nutrients should be divided into individual components

(e.g. nitrogen and phosphorous) due to marsh limitation to a single nutrient

 Salinity is roughly covered in the model by the adjustment of bulk density and

primary productivity, but the parameter is not explicitly covered and habitat

switching is not tracked

 Spatial complexity/geometry improvements

 Inclusion of coastal currents and erosion, major storm events, and wind erosion

 Better methods of accounting for hydraulic resistance

17

1606
Acknowledgements

This effort was developed and funded under the Louisiana Coastal Protection and

Restoration (LACPR) Program of the U.S. Army Corps of Engineers. The authors would

like to acknowledge the LACPR Habitat Evaluation Team (HET), and their extensive

technical guidance of the development of the technology presented herein. In particular,

Ronald Paille and Tamieka Armstrong provided critical feedback on formulation and

application of the model. Ron Boustany provided the basis for the nutrient model

presented herein and the authors are grateful for his willingness to assist in this effort.

Gregg Snedden, Joann Mossa, Robert Lane, and Mike Channell all provided valuable

data and knowledge resources throughout the development of this model.

18

1607
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Figures

Figure 1. Typical coastal Louisiana marsh community with a patchwork of dense

vegetation and open water

24

1613
Figure 2. Conceptual model of coastal Louisiana marsh accretionary processes

(from Day et al., 1995)

25

1614
-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

-3.14 -1.57 0 1.57 3.14 4.71 6.28

Tide Phase, 

Velocity, u

udiv utide utotal

0 1 2

Figure 3. Wetland velocity with diversion and tidal components

26

1615
Figure 4. Aerial view of Breton Sound displaying Caernarvon Diversion and

project division areas for tracking land evolution. In this analysis only the following

areas were considered to be directly influenced by the Caernarvon Diversion in

order to maintain relative uniformity in conditions: Upper Reference Outfall East,

Upper Project Outfall, Upper Reference West, Middle Reference West, and Middle

Project Area.

27

1616
0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

J FMAMJ J ASOND

Date

Diversion Discharge, Qdiv (cfs)

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

Mississippi River Discharge, Qriver (cfs)

Diversion River

Figure 5. Representative diversion and river hydrographs for land evolution

forecasting associated with the Caernarvon Diversion (1994 hydrographs)

28

1617
54,000

56,000

58,000

60,000

62,000

64,000

66,000

68,000

70,000

72,000

74,000

76,000

78,000

80,000

82,000

84,000

86,000

88,000

90,000

N-90 N-91 N-92 N-93 N-94 N-95 N-96 N-97 N-98 N-99 N-00 N-01 N-02 N-03 N-04 N-05 N-06 N-07

Date

Land Area (ac)

Observed Hurricanes First Diversion FWOP Median 90% Confidence Boustany

Figure 6. Marsh area prediction for the Caernarvon Diversion from 1990-2006 with

observed acreages, model predictions with parameter uncertainty bounds, as well as

the Boustany Model predictions

29

1618
68,000

70,000

72,000

74,000

76,000

78,000

80,000

82,000

84,000

86,000

88,000

N-90 N-92 N-94 N-96 N-98 N-00 N-02 N-04 N-06 N-08 N-10 N-12 N-14 N-16 N-18 N-20 N-22 N-24 N-26 N-28 N-30 N-32 N-34 N-36 N-38 N-40

Date

Land Area (ac)

FWOP Sediment Only Nutrient Only Synergistic

Figure 7. Marsh area prediction for the Caernarvon Diversion from 1990-2040 with

isolated nutrient and sediment benefits

30

1619
0

2000

4000

6000

8000

10000

12000

14000

16000

J FMAMJ J ASOND

Date

Diversion Discharge, Qdiv (cfs)

0

200000

400000

600000

800000

1000000

1200000

1400000

Mississippi River Discharge, Qriver (cfs)

2003 Large - In Large - Out Small - In Small - Out Constant MS River - 1994

Figure 8. Hydrographs considered in Caernarvon Diversion operational

optimization

31

1620
72000

74000

76000

78000

80000

82000

84000

86000

88000

2001 2006 2011 2016 2021 2026 2031 2036 2041 2046

Date

Marsh Area (ac)

2003 Large - In Large - Out Small - In Small - Out Constant

Figure 9. Land evolution predictions for multiple operational scenarios at the

Caernarvon Diversion

32

1621
0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

J FMAMJ J ASOND

Date

Diversion Discharg,e Qdiv (cfs)

0

200000

400000

600000

800000

1000000

1200000

1400000

Gate - 2003 Weir - 100ft Weir - 200ft Siphon-1 X 15ft Pipe Siphon- 1 X 6ft Pipes MS River - 1994

Figure 10. Calculated hydrographs for various structure types at the Caernarvon

Diversion

33

1622
75000

80000

85000

90000

95000

100000

105000

110000

115000

2001 2006 2011 2016 2021 2026 2031 2036 2041 2046

Date

Marsh Area (ac)

Gate - 2003 Weir - 100ft Weir - 200ft Siphon-1 X 15ft Pipe Siphon-1 X 6ft Pipe

Figure 11. Land evolution predictions for various structure types at the

Caernarvon Diversion

34

1623
Tables

Table 1. Sediment Ratings for Rivers on the Louisiana Coastal Plain

River Gauge Location a1 a2 R2

Mississippi Belle Chase Surface* 3.205E-07 2.000 0.6648

Belle Chase 1.237E-08 2.320 0.7302

Tarbert - 1949-1975 1.192E-04 1.702 0.7945

Tarbert - 1975-2007 7.096E-03 1.342 0.7689

St. Francisville 6.501E-04 1.507 0.7357

Atchafalaya Melville 4.941E-06 1.937 0.7764

Simmesport 8.286E-04 1.563 0.8138

All ratings developed from suspended sediment concentrations and water

discharges from USGS Website except "Belle Chase Surface"

*

Surface concentrations of suspended sediment at Belle Chase and Tarbert's

Landing Discharges (Snedden et al., 2007)

35

1624
36

Table 2. Hydraulic roughness height as a function of bed material grain size

Channel Boundary Roughness Height, z0

1

ft mm m

Mud 6.6E-04 0.2 2.0E-04

Mud/Sand 2.3E-03 0.7 7.0E-04

Silt/Sand 1.6E-04 0.05 5.0E-05

Sand (unrippled) 1.3E-03 0.4 4.0E-04

Sand (rippled) 2.0E-02 6 6.0E-03

Sand/Shell 9.8E-04 0.3 3.0E-04

Sand/Gravel 9.8E-04 0.3 3.0E-04

Mud/Sand/Gravel 9.8E-04 0.3 3.0E-04

Gravel 9.8E-03 3 3.0E-03

1

Adapted from Soulsby (1983, Table 5.4)

1625
Table 3. System properties and land evolution model parameters for the Caernarvon Diversion to Breton Sound Estuary

Parameter

Best

Estimate

Approximate

Standard Deviation

General System Properties

Initial Land Area (ac)# 86,591 -

Project Area (ac)# 148,018 -

Average Water Depth,

H (ft)* 3 0.5

Average Water Width,

B (ft) 65,000# 1,000*

Maximum Tidal Velocity,

Utide,max (ft/s)* 0.6 0.1

Roughness Height, zo (ft)* 0.005 0.0005

Land Loss Rate (%/y)1 -0.42 0.042

Bulk Density,

bd (g/cm3

) 0.26 -

Sediment Rating of Surface Concentrations of the Mississippi River at Belle Chase2

Coefficient 3.205E-07 3.21E-08

Exponent 2.000 -

Size Fraction of Belle Chase Rating2

Sand 0.01 0.0017

Silt 0.63 0.1050

Clay 0.36 -

Floc Fraction* 0.3 0.0667

37

1626
38

Parameter

Best

Estimate

Approximate

Standard Deviation

Approximate Fall Velocity3 (m/s)

Sand 1.00E-02 8.33E-04

Silt 3.00E-04 2.50E-05

Clay 7.00E-06 5.83E-07

Floc Fraction 2.00E-04 4.00E-05

Marsh Nutrient Requirements

Plant Productivity Rate, Pr (g/m2yr)* 4,150 415

Percent of N and P in Plant Biomass, TNP(%)4 0.72 0.072*

Nutrient Loading to Marsh

Background Concentration of N and P, Cbackground (mg/L)5 0.34 0.034*

Sourcewater Concentration of N and P, Csource (mg/L)# 2.28 0.5*

Nutrient Retention, Rnut (%)* 50 10

1Land loss rate calculated from observed marsh acreage from 1978-1990

2Data for rating and size fraction from Snedden et al. (2007)

3Calculated from method of Soulsby (1997)

4Foote and Reynolds (1997)

5Hyfield (2004)

#Available data

*Best professional judgment

1627
Symbols

b = Rouse parameter

d = Diameter of siphon

fi = Sediment size fraction i

g = Acceleration due to gravity

u* = Shear velocity

x = Longitudinal or down-marsh coordinate

y = Horizontal or cross-marsh coordinate

z = Vertical coordinate

z0 = Hydraulic roughness length

za = Reference depth

zriver = River stage

zmarsh = Marsh Elevation

zweir = Weir Elevation

A = Marsh area

Aveg = Vegetated area of receiving area

Anut = Total aerial nutrient benefit from flow diversion

Ased = Total aerial sediment benefit from flow diversion

Asiphon = Cross-sectional area of siphon

B = Average marsh width

BB

weir = Weir width

C = Suspended sediment concentration

Ca = Suspended sediment concentration at reference elevation za

Criver = Suspended sediment concentration of river

Csource = Nutrient concentration of source water

Cweir = Theoretical weir coefficient

Esus = Percent of wetland sustained by nutrient loading

H = Average marsh depth

Kz = Vertical diffusivity

L = Average marsh length

LRreq = Marsh required nutrient loading rate

LRdiv = Loading rate of nutrients from the flow diversion

LRbackground = Background loading rate of nutrients from preexisting marsh sources

LRnet = Net loading rate of nutrients from diversion and background sources (=LRdiv -

LRbackground)

Pr = Primary Production

Qdiv = Volumetric water discharge through diversion

Qs,river = Sediment discharge of river

Qs,div = Sediment discharge of diversion

Qs,net = Rate of sediment discharged to and retained in marsh

Ri = Sediment retention of size fraction i

RT = Total sediment retention factor

T = Time required for particle settling

U = Daily mean velocity with tidal and diversion related components

Ui = Instantaneous mean velocity with tidal and diversion related components

39

1628
Udiv = Diversion induced velocity (= Qdiv / HB)

Umax,tide = Maximum tidal velocity (tidal velocity amplitude)

Vsiphon = Velocity of flow in siphon

Ws = Natural settling velocity

Ws,eff = Effective settling velocity due to natural settling and turbulence

X = Transport distance of suspended sediment

 = Land change rate (% / time)

nut = Nutrient suppressed land change rate (% / time)

nut = Percent of plant biomass made up of nutrients

 = von Karmans constant (0.4)

 = Tide phase

0 = Tide phase of the up-crossing zero velocity

1 = Tide phase of the down-crossing zero velocity (=0+ )

2 = 0+ 2

40

1629
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Annex 4. SAND2 and WVA Data Summary Tables.Table 1. SAND2 Model Determined Wetland Acreages Associated with Study Area Polygons Receiving Diversion Benefits (or Impacts).

Palmetto Bayou,

Creole Bayou

A6, A&, Lake

Pagie

C9 C2-C7 Bayou Dulac E2-E4 G2, G3, G6 F2 G1, G5 B6, B7 C11-C14 TOTAL

Net

FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP TY50

TY Year (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres)

0 2015 50,083 50,083 16,569 16,569 960 960 13,003 13,003 2,393 2,393 7,133 7,133 17,466 17,466 1,428 1,428 20,401 20,401 23,931 23,931 19,924 19,924 346,581 346,581

Alt 2 1 2016 50,046 50,046 16,337 16,451 947 957 12,757 12,728 2,368 2,408 6,590 6,563 17,156 17,243 1,357 1,342 20,327 20,074 23,742 23,742 19,715 19,734 171,340 171,287

10 2025 49,710 49,710 14,245 15,443 827 933 10,543 10,683 2,143 2,176 1,696 1,669 14,365 15,244 717 574 19,662 19,409 22,042 22,110 17,837 17,844 153,786 155,79450 2065 48,217 48,217 6,343 14,230 286 882 2,925 3,766 1,145 885 0 0 5,188 10,010 0 0 16,930 16,677 14,486 17,276 9,488 2,961 105,007 114,902 9,895

Alt 3 1 2016 50,046 50,046 16,337 16,455 947 957 12,757 12,728 2,368 2,408 6,590 6,563 17,156 17,244 1,357 1,342 20,327 20,074 23,742 23,742 19,715 19,735 171,340 171,293

10 2025 49,710 49,710 14,245 15,475 827 935 10,543 10,686 2,143 2,176 1,696 1,669 14,365 15,254 717 574 19,662 19,409 22,042 22,111 17,837 17,849 153,786 155,84750 2065 48,217 48,217 6,343 14,361 286 889 2,925 3,779 1,145 893 0 0 5,188 10,068 0 0 16,930 16,677 14,486 17,319 9,488 2,979 105,007 115,181 10,174

Alt 4 1 2016 50,046 50,046 16,337 16,451 947 957 12,757 12,726 2,368 2,408 6,590 6,563 17,156 17,310 1,357 1,343 20,327 20,074 23,742 23,742 19,715 19,732 171,340 171,351

10 2025 49,710 49,710 14,245 15,435 827 926 10,543 10,666 2,143 2,176 1,696 1,669 14,365 15,908 717 586 19,662 19,409 22,042 22,109 17,837 17,823 153,786 156,41650 2065 48,217 48,217 6,343 14,126 286 846 2,925 3,682 1,145 879 0 0 5,188 12,886 0 0 16,930 16,677 14,486 17,253 9,488 2,938 105,007 117,503 12,495

Alt 5 1 2016 50,046 50,046 16,337 16,452 947 957 12,757 12,726 2,368 2,390 6,590 6,563 17,156 17,310 1,357 1,343 20,327 20,074 23,742 23,742 19,715 19,733 171,340 171,336

10 2025 49,710 49,710 14,245 15,452 827 927 10,543 10,668 2,143 2,397 1,696 1,669 14,365 15,908 717 586 19,662 19,409 22,042 22,110 17,837 17,833 153,786 156,67050 2065 48,217 48,217 6,343 14,275 286 853 2,925 3,690 1,145 1,994 0 0 5,188 12,887 0 0 16,930 16,677 14,486 17,302 9,488 2,963 105,007 118,858 13,850

Alt 6 1 2016 50,046 50,046 16,337 16,337 947 947 12,757 12,707 2,368 2,379 6,590 6,590 17,156 17,196 1,357 1,358 20,327 20,327 23,742 23,742 19,715 19,715 171,340 171,344

10 2025 49,710 49,710 14,245 14,265 827 827 10,543 10,480 2,143 2,279 1,696 1,696 14,365 14,768 717 739 19,662 19,662 22,042 22,095 17,837 17,668 153,786 154,18850 2065 48,217 48,217 6,343 7,205 286 286 2,925 2,862 1,145 2,578 0 0 5,188 7,364 0 0 16,930 16,930 14,486 16,678 9,488 2,535 105,007 104,654 -354

Alt 7 1 2016 50,046 50,046 16,337 16,337 947 947 12,757 12,709 2,368 2,368 6,590 6,590 17,156 17,156 1,357 1,357 20,327 20,327 23,742 23,742 19,715 19,715 171,340 171,292

10 2025 49,710 49,710 14,245 14,265 827 827 10,543 10,495 2,143 2,175 1,696 1,696 14,365 14,365 717 717 19,662 19,662 22,042 22,095 17,837 17,668 153,786 153,67550 2065 48,217 48,217 6,343 7,194 286 286 2,925 2,877 1,145 2,458 0 0 5,188 5,188 0 0 16,930 16,930 14,486 16,676 9,488 2,532 105,007 102,357 -2,651

Alt 8 1 2016 50,046 50,046 16,337 16,335 947 956 12,757 12,728 2,368 2,368 6,590 6,590 17,156 16,972 1,357 1,342 20,327 20,327 23,742 23,742 19,715 19,715 171,340 171,120

10 2025 49,710 49,710 14,245 14,243 827 917 10,543 10,685 2,143 2,133 1,696 1,696 14,365 14,888 717 573 19,662 19,662 22,042 22,099 17,837 17,673 153,786 154,27950 2065 48,217 48,217 6,343 7,011 286 684 2,925 3,772 1,145 727 0 0 5,188 9,151 0 0 16,930 16,930 14,486 16,822 9,488 2,707 105,007 106,021 1,013

1630
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Table 2. Wetland Acreages Associated with Independent Measures (i.e. measures that are not associated with diversion benefits).nf  not a feature of that alternative

dm  benefits incorporated in diversion modeled benefits

WO2 WD2 WD3 CD1 CD3 CD4 CD7 - channel CD7 -

nourishment

CT1,6,7,8 EM3 ED5 TOTAL TOTAL TOTAL

TY50 TY50 TY50

FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP FWOP FWP diff

TY (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres) (acres)

0 375.0 375.0 319.0 319.0 0.0 0.0 6.0 6.0 8.5 8.5 0.0 0.0 7.7 7.7 80.3 80.3 0.0 0.0 0.0 0.0 15.3 5.3

Alt 2 1 nf nf 319.0 0.0 0.0 0.0 6.0 0.0 8.5 0.0 0.0 0.0 7.7 0.0 80.3 83.6 0.0 120.0 0.0 72.0 15.3 0.0

10 nf nf 319.0 0.0 0.0 0.0 5.5 0.0 8.3 0.0 0.0 0.0 8.2 0.0 80.3 83.6 0.0 108.8 0.0 68.2 15.1 0.050 nf nf 319.0 0.0 0.0 0.0 3.4 0.0 7.6 0.0 0.0 0.0 10.2 0.0 76.3 80.3 0.0 59.0 0.0 51.2 14.1 0.0 430.6 190.5 -240.1

Alt 3 1 367.5 375.0 319.0 0.0 0.0 0.0 6.0 0.0 8.5 0.0 0.0 0.0 7.7 0.0 80.3 83.6 0.0 120.0 0.0 72.0 15.3 0.0

10 300.0 375.0 319.0 0.0 0.0 0.0 5.5 0.0 8.3 0.0 0.0 0.0 8.2 0.0 80.3 83.6 0.0 108.8 0.0 68.2 15.1 0.050 0.0 375.0 319.0 0.0 0.0 0.0 3.4 0.0 7.6 0.0 0.0 0.0 10.2 0.0 76.3 80.3 0.0 59.0 0.0 51.2 14.1 0.0 430.6 565.5 134.9

Alt 4 1 nf nf 319.0 0.0 0.0 0.0 6.0 0.0 8.5 0.0 0.0 0.0 7.7 0.0 80.3 83.6 0.0 120.0 dm dm 15.3 0.0

10 nf nf 319.0 0.0 0.0 0.0 5.5 0.0 8.3 0.0 0.0 0.0 8.2 0.0 80.3 83.6 0.0 108.8 dm dm 15.1 0.050 nf nf 319.0 0.0 0.0 0.0 3.4 0.0 7.6 0.0 0.0 0.0 10.2 0.0 76.3 80.3 0.0 59.0 dm dm 14.1 0.0 430.6 139.3 -291.3

Alt 5 1 367.5 375.0 319.0 0.0 0.0 0.0 6.0 0.0 8.5 0.0 0.0 0.0 7.7 0.0 80.3 83.6 0.0 120.0 dm dm 15.3 0.0

10 300.0 375.0 319.0 0.0 0.0 0.0 5.5 0.0 8.3 0.0 0.0 0.0 8.0 0.0 80.3 83.6 0.0 108.8 dm dm 15.1 0.050 0.0 375.0 319.0 0.0 0.0 0.0 3.4 0.0 7.6 0.0 0.0 0.0 10.2 0.0 76.3 80.3 0.0 59.0 dm dm 14.1 0.0 430.6 514.3 83.7

Alt 6 1 367.5 375.0 nf nf 0.0 0.0 nf nf nf nf nf nf nf nf nf nf nf nf nf nf 15.3 0.0

10 300.0 375.0 nf nf 0.0 0.0 nf nf nf nf nf nf nf nf nf nf nf nf nf nf 15.1 0.050 0.0 375.0 nf nf 0.0 0.0 nf nf nf nf nf nf nf nf nf nf nf nf nf nf 14.1 0.0 14.1 375.0 360.9

Alt 7 1 nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf

10 nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf50 nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf nf 0.0 0.0 0.0

Alt 8 1 nf nf nf nf nf nf 6.0 0.0 nf nf nf nf 7.7 0.0 80.3 83.6 nf nf nf nf 15.3 0.0

10 nf nf nf nf nf nf 5.5 0.0 nf nf nf nf 8.2 0.0 80.3 83.6 nf nf nf nf 15.1 0.050 nf nf nf nf nf nf 3.4 0.0 nf nf nf nf 10.2 0.0 76.3 80.3 nf nf nf nf 14.1 0.0 104.0 80.3 -23.7

1631
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Table 3. Total Wetland Acreage Benefits (or Impacts) by Alternative.

:
	

7


(



 #	



 0 9895.0 -240.1 9655.0
 2 10173.7 134.9 10308.5
  12495.5 -291.3 12204.2
 3 13850.1 83.7 13933.8
 4 -353.8 360.9 7.1
 A -2650.7 0.0 -2650.7
 < 1013.1 -23.7 989.4

1632
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

Table 4. Summary of Wetland Value Assessment Variables Associated with each Alternative and Target Year*.

L	 "
	 
 0 
 2 
  
 3 
 4 
 A 
 <

Var. #)6 #)* #)*6 #)36 #)* #)*6 #)36 #)* #)*6 #)36 #)* #)*6 #)36 #)* #)*6 #)36 #)* #)*6 #)36 #)* #)*6 #)36 #)* #)*6 #)36

Palmetto/Creole Bayou Area  Fresh Marsh - 57,585 acres

V1 <A6 <4? <42 <2A <4? <42 <2A <4? <42 <2A <4? <42 <2A <4? <42 <2A <4? <42 <2A <4? <42 <2A <4? <42 <2AV2 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66 A66

V3-1 <66 A?6 A36 3<6 A?6 A36 3<6 A?6 A36 3<6 A?6 A36 3<6 A?6 A36 3<6 A?6 A36 3<6 A?6 A36 3<6 A?6 A36 3<6V3-2 066 0*6 036 06 0*6 036 06 0*6 036 06 0*6 036 06 0*6 036 06 0*6 036 06 0*6 036 06 0*6 036 06V3-3 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66V3-4 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66V3-5 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66

V4 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66V5 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66V6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6

G- E& 4& A 
 F 7
"- 
  3?&46 "


V1 043 04* 004 ?4 0AA 046 02? 0AA 046 00 0AA 046 02< 0AA 046 06 0A3 06 *0* 0A3 06 *0* 0A3 06 **<V2 66 66 2A6 06 36 36 66 36 36 66 36 36 66 36 36 26 66 2A6 06 66 2A6 0<6 236 26 0<6

V3-1 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66V3-2 *66 A6 66 66 *66 A6 66 *66 A6 66 *66 A6 66 *66 A6 66 *66 46 66 *66 46 66 *66 46 66V3-3 *26 *A6 *36 66 *36 *A6 036 *36 *A6 036 *36 *A6 036 *36 *A6 036 *36 *6 66 *36 *6 66 *36 *6 66V3-4 206 206 6 66 26 2*6 046 26 2*6 0<6 26 2*6 036 26 2*6 0A6 226 266 *6 226 266 *6 226 266 *06V3-5 36 6 *6 *666 *6 36 ?6 *6 36 A6 *6 36 366 *6 36 <6 06 366 <46 06 366 <46 06 366 <<6

V4 *66 *66 ?6 06 *66 *66 ?6 *66 *66 ?6 *66 *66 ?6 *66 *66 ?6 *66 ?6 26 *66 ?6 26 *66 ?6 26V5 0? 0? 0? 0A 00 *? *4 00 *? *4 04 03 *? 03 0 *? 0? 0< 03 0? 0< 04 20 2* 0?V6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6

80& 82& 84 
 F 7
"- 
  2<&04? "


V1 34 < 2A3 *24  2?0 03A  2?0 03? ? 4 3*4 ? 4 3*4  2<* *<4 < 2A3 *24  2<? 02?V2 26 26 06 66 36 36 06 36 36 06 *36 *6 *06 *36 *6 *06 36 36 06 26 06 66 36 36 06

V3-1 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66 *66 66 66 66 66V3-2 066 066 *06 66 066 *66 66 066 *66 66 066 *26 66 066 *26 66 066 *66 66 *?6 66 66 066 *26 66V3-3 06 2?6 26 66 66 2?6 *36 66 2?6 *36 66 66 2<6 66 66 2<6 66 26 66 06 266 66 2<6 246 *A6V3-4 2<6 *6 *6 06 66 3*6 4A6 66 3*6 4<6 66 A6 3A6 66 A6 3A6 66 346 4*6 2<6 366 06 06 66 A6V3-5 66 66 *26 A46 66 66 *<6 66 66 *A6 66 66 36 66 66 36 66 66 2?6 66 *66 A46 66 **6 246

V4 <6 <6 A6 06 <6 <6 6 <6 <6 6 <6 <6 46 <6 <6 46 <6 A6 26 <6 A6 06 <6 <6 6V5 <2 <2 <4 *66 44 4? <6 4 4? A< *A *< 0< *A *< 0< 4< 4? < <2 <2 ?4 4? 4< A<V6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6 *6

8*  83 
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1633
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

90 
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1634
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of Houma Navigation Lock  Appendix M  Wetland Value Assessment (WVA)

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1636
APPENDIX N:

Phase I Environmental Site Assessment

1637

Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix N  Environmental Assessment

N-1

Volume III

APPENDIX N:

Phase I Environmental Site Assessment

LCA ARNTM

Mississippi River Delta, Louisiana

HTRW Initial Assessment (IA) Documentation

EXECUTIVE SUMMARY

Coastal Louisiana covers a vast area and consists of a variety of physiographic features such

as estuaries, wetlands, rivers, urban areas and flood control structures. In particular, the

Atchafalaya Basin, at nearly 1 million acres, is the nations largest river-swamp system

(Demas et al. 2001). Located in south central Louisiana, the system stretches from the rivers

origin near Simmesport to its termination into the Atchafalaya Bay. It is contained on its east

and west borders by flood protection levees. Water flow into the Atchafalaya Basin is

controlled at the Old River control structure. The structure diverts approximately 30% of the

Mississippi River water down through the Atchafalaya Basin.

The Terrebonne Basin is bordered by Bayou Lafourche on the east, the Atchafalaya Basin

floodway on the west, and the Gulf of Mexico on the south. The Terrebonne Basin is an

abandoned delta complex characterized by a thick section of unconsolidated sediments that

are undergoing dewatering and compaction. The Terrebonne Basin supports about 155,000

acres of swamp and almost 574,000 acres of marsh, grading from fresh marsh inland to

brackish and saline marsh near the bays and gulf.

The restoration project to convey Atchafalaya River water to the northern Terrebonne

marshes would increase existing Atchafalalya River influence to central (Lake Boudreaux)

and eastern (Grand Bayou) Terrebonne marshes via the Gulf Intracoastal Waterway

(GIWW).

Restoration features may include increasing freshwater flow into the northern Terrebonne

marshes through repairing banks along the GIWW, enlarging constrictions within the

GIWW, and diverting additional Atchafalaya River freshwater into the Bayou Chene/GIWW

system.

A Phase I Environmental Assessment (HTRW Initial Assessment) was conducted to satisfy

the requirement of ER-1165-2-132, HTRW Guideline for Civil Works Projects, and to

address the impact of any Recognized Environmental Condition (RECs) for the areas

designated in the project scope of work. The objective of this Environmental Assessment is

to identify, to the extent feasible pursuant to the processes described herein, recognized

environmental conditions in connection with the designated target property. Based upon data

reviewed and observations made within the project area, this assessment revealed that all of

1639
Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix N  Environmental Assessment

N-2

the potential alternatives for this project have a low to moderate chance in encountering

HTRW during the construction phase of this project. However the impact that the

construction and subsequent operation of this project has on HTRW is low.

ASSESSMENT FINDINGS

Summary of Results

HTRW Initial Assessment documentation for the restoration project was prepared on all

project features that did not trigger other environmental regulations such as dredging or marsh

creation which are covered under either section 404 of the Clean Water Act (CWA), or section

103 of the Marine Protection, Research, and Sanctuaries Act. Or the administrative equivalent

of such permits where the work involves an Army Corps of Engineers civil works project, 40

C.F.R. 261.4(g), 63 F.R. 65874, 65921; November 30, 1998. ER1165-2-132 states, dredged

material and sediments beneath navigable waters proposed for dredging qualify as HTRW only

if they are within the boundaries of a site designated by the EPA or a state for a response action

(either a removal or a remedial action) under CERCLA, or if they are a part of a NPL site

under CERCLA. In conformance with the scope and limitations of ASTM Practice 1527-05

with exceptions to or deletion from this practice are documented in Section 9.0 of this report.

Risk Assessment

The environmental professionals who have conducted the site visit and reviewed the results

of the data collection effort have concluded that the following are Recognized

Environmental Conditions which may have the following range of qualitative impacts on

the soil and water resources on the subject properties.

Feature Recognized Environmental Condition Potential Environmental Impact

CP1 Marked under-canal pipeline Moderate

located at the target property

EC5 & ES2 Known Large Quantity Generator of Hazardous Waste Moderate

within one-quarter mile (Bollinger Larose, LLC)

EC6 Adjacent Property Waste Disposal site Moderate

(US Liquids)

EC7 Pipes carrying unknown contents Moderate

Above ground tank on adjacent property Moderate

Adjacent Property Waste Disposal site Moderate

(US Liquids)

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Volume III  Convey Atchafalaya River Water to Northern Terrebonne Marshes and Multipurpose Operation of

Houma Navigation Lock  Appendix N  Environmental Assessment

N-3

8.3 Recommendations

This assessment has revealed the aforementioned moderate evidence of Recognized

Environmental Conditions in connection with five potential features that are included in

Alternatives 2 through 5 and Alternative 8. All other features within the alternatives have no to

low impact. Based upon the data reviewed and observations made within the immediate areas

of the target property coordinates, no further environmental actions are warranted at this time.

If further information is needed on the Phase 1 please contact USACE St. Louis District ECHMQ at 314-865-6311.

1641

APPENDIX P:

Project Costs and Schedule Risk Analysis

Report

1643
LCA CONVEY ATCHAFALAYA RIVER WATER TO

NORTHERN TERREBONNE MARSHES AND

MULTIPURPOSE OPERATION OF THE HOUMA

NAVIGATION LOCK

FEASIBILITY STUDY

FOR

ST. LOUIS DISTRICT, ST. LOUIS, MO

Prepared for:

St. Louis District, St. Louis, MO __

Prepared by:

Paige Scott __________________

Date: __03 May 2010 ________

1644
i

TABLE OF CONTENTS

EXECUTIVE SUMMARY ................................................................................................ 1

1. PURPOSE ................................................................................................................. 3

2. BACKGROUND......................................................................................................... 3

3. REPORT SCOPE ...................................................................................................... 3

3.1 Project Scope .................................................................................................... 4

3.2 USACE Risk Analysis Process .......................................................................... 4

4. METHODOLOGY/PROCESS.................................................................................... 5

4.1 Identify and Assess Risk Factors....................................................................... 6

4.2 Quantify Risk Factor Impacts............................................................................. 7

4.3 Analyze Cost Estimate and Schedule Contingency ........................................... 8

5. KEY ASSUMPTIONS ................................................................................................ 9

6. RISK ANALYSIS RESULTS ..................................................................................... 9

6.1 Risk Register ..................................................................................................... 9

6.2 Cost Risk Analysis - Cost Contingency Results............................................... 11

6.3 Schedule Risk Analysis - Schedule Contingency Results................................ 13

6.4 Combined Cost and Schedule Contingency Results........................................ 15

7. MAJOR FINDINGS/OBSERVATIONS .................................................................... 16

8. MITIGATION RECOMMENDATIONS ..................................................................... 17

LIST OF TABLES

Table 1. Work Breakdown Structure by Feature ............................................................ 6

Table 2. Studied Risk Register....................................................................................... 8

Table 3. Cost Confidence Table.................................................................................... 10

Table 4. Schedule Confidence Table ............................................................................ 13

Table 5. Combined Confidence Table........................................................................... 14

Table 6. Project Contingencies (Base Cost Plus Cost and Schedule Contingencies).. 15

FIGURE

Figure 1. Cost Sensitivity Chart..................................................................................... 10

Figure 2. Cost Confidence Curve .................................................................................. 11

Figure 3. Schedule Sensitivity Chart ............................................................................. 12

Figure 4. Schedule Confidence Curve........................................................................... 13

Figure 5. Project Confidence Curve ............................................................................. 15

1645
ii

APPENDIX

APPENDIX A Detailed Risk Register

1646
ES-1

EXECUTIVE SUMMARY

This report discusses the cost and schedule risk analysis (CSRA) process and results

for the Convey Atchafalaya River Water to Northern Terrebonne Marshes (ARTM)

Feasibility Study. The ARTM project is located in the vicinity of Houma. A CSRA was

performed to study project elements that could have an impact on the project cost and

schedule. The CSRA measures that impact with a contingency calculation outcome

based on an eighty (80) percent confidence level for both cost and schedule that are

measured in terms of dollars and months, respectively.

The ARTM Study Area is comprised of over 500 square miles of southern Louisiana in

the vicinity of Houma. The western limit of the study area is the Atchafalaya River at

Morgan City in St. Mary Parish. The eastern limit of the ARTM study area is bordered

by Bayou LaFourche in LaFourche Parish. A large extent of the study area lies in

Terrebonne Parish adjacent to and south of State Highways 182 and 24.

The ARTM project is one of the Louisiana Costal Authority (LCA) projects, and is

authorized by Title VII of the WRDA of 2007. Currently, the ARTM project is at

feasibility design development phase. The ARTM diversion project involves

construction of 56 structures and other water management features. There are two

water diversion type structures that are at critical points in the Terrebonne Marshes. The

Central Diversion Structure (CS1) which involves constructing six 10' x 10' gated box

culverts on Bayou Butler under Highway 57. The Eastern Culvert #5 (EC 5) is

composed of a bridge with five 83 foot spans with two 68.5 foot spans accommodating

Highway 24. Associated with this bridge are five 80 foot Obermeyer gated openings, for

a total flow opening width of 400 feet. The project also includes dredging, bank

protection, berms, soil plugs, and other culvert structures.

 A cost and schedule risk analysis is conducted by identifying and assessing

risk items for use in the risk analysis. These quantitative impacts of these

risk items are then analyzed using a combination of professional judgment,

empirical data, and analytical techniques. The total project cost contingency

is then analyzed using the Crystal Ball software. Monte Carlo simulations

are performed by applying the risk factors (quantified as probability density

functions) to the appropriate estimated cost and schedule elements

identified by the PDT. A PDT meeting was held at the RAY Building in St.

Louis, Missouri, for the purpose of identifying and assessing risk factors.

The meeting included the Civil Engineer, Geotechnical Engineer, Cost

Engineer, and Hydraulic Engineer/Technical Manager.

Some key project assumptions were made to complete the risk analysis. To complete

the schedule analysis, it was assumed that the planning, engineering, and design phase

of the project would last one year, allowing the first phase of construction to start in

2012. This assumption also affects the cost estimate escalation amount used. In the

cost analysis & estimate, it was assumed that the project would be constructed under

multiple contracts with a prime contractor and multiple subcontractors.

1647
ES-2

The cost and schedule risk analysis resulted in a recommended cost contingency of

$51,103,261 and a schedule recommended contingency of 58 months. Those two

results are combined to produce a total project contingency. The recommended total

project contingency is 34%, or $68,353,130, based on the 80% confidence level. This

contingency was applied to the detailed estimate for the Recommended Plan (RP) for

the ARTM project.

1648
P-1

1. PURPOSE

This report discusses the cost and schedule risk analysis (CSRA) process and results

for the Convey Atchafalaya River Water to Northern Terrebonne Marshes (ARTM)

Feasibility Study. The ARTM project is located in the vicinity of Houma. A CSRA was

performed to study project elements that could have an impact on the project cost and

schedule. The CSRA measures that impact with a contingency calculation outcome

based on an eighty (80) percent confidence level for both cost and schedule that are

measured in terms of dollars and months, respectively.

2. BACKGROUND

The ARTM Study Area is comprised of over 500 square miles of southern Louisiana in

the vicinity of Houma. The study is western limit is the Atchafalaya River at Morgan City

in St. Mary Parish, eastern limit of the ARTM study area is bordered by Bayou

LaFourche in LaFourche Parish. A large extent of the study area lies in Terrebonne

Parish adjacent to and south of State Highways 182 and 24.

The ARTM restoration project would increase existing Atchafalaya River influence to

central (Lake Boudreaux) and eastern (Grand Bayou) Terrebonne marshes via the

GIWW by introducing flow into the Grand Bayou Basin. This will be accomplished by

enlarging the connecting channel (Bayou LEau Bleu) to capture as much of the surplus

flow (max. 2000 to 4000 cfs) that would otherwise leave the Terrebonne Basin. Gated

control structures would be installed to restrict channel cross-sections to prevent

increased saltwater intrusion during the late summer and fall when Atchafalaya River

influence is typically low. Some auxiliary freshwater distribution structures may be

included. The ARTM project is one of the Louisiana Costal Authority (LCA) projects, and

is authorized by Title VII of the WRDA of 2007. Currently, the ARTM project is at

feasibility design development phase.

3. REPORT SCOPE

The scope of the risk analysis report is to calculate and present the cost and schedule

contingencies at the 80 percent confidence level using the risk analysis processes as

mandated by U.S. Army Corps of Engineers (USACE) Engineer Regulation (ER) 1110-

2-1150, Engineering and Design for Civil Works, ER 1110-2-1302, Civil Works Cost

Engineering, and Engineer Technical Letter 1110-2-573, Construction Cost Estimating

Guide for Civil Works. The report presents the contingency results for both cost and

schedule risks for all project features. The study and presentation can include or

exclude consideration for operation and maintenance or life cycle costs, depending

upon the program or decision document intended for funding.

3.1 Project Scope

Title VII of the WRDA of 2007 authorizes the LCA program. The authority includes

requirements for comprehensive coastal restoration planning, program governance,

project modification investigations, a Science and Technology (S&T) program,

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restoration project construction, a program for beneficial use of dredged material,

feasibility studies for restoration plans, and other program elements. In total the LCA

program has authority for 25 elements falling into various categories including

investigations, research, demonstrations, and construction.

The ARTM diversion project involves construction of 56 structures and other water

management features. There are two water diversion type structures that are at critical

points in the Terrebonne Marshes. The Central Diversion Structure (CS1) which

involves constructing six 10' x 10' gated box culverts on Bayou Butler under Highway

57. The Eastern Culvert #5 (EC5) is composed of a bridge with five 83 foot spans with

two 68.5 foot spans accommodating Highway 24. Associated with this bridge are five

80 foot Obermeyer gated openings, for a total flow opening width of 400 feet. The

project also includes dredging, bank protection, berms, soil plugs, and other culvert

structures.

The report includes the project technical scope, estimates, and schedules as developed

and presented by the St. Louis and New Orleans Districts. Consequently, these

documents serve as the basis for the risk analysis. In general terms, the construction

scope consists of the following:

 Major project features studied from the civil works work breakdown

structure (CWWBS) include:

 01 LANDS AND DAMAGES

 02 RELOCATIONS

 08 ROADS, RAILROADS, AND BRIDGES

 09 CHANNELS AND CANALS

 11 LEVEES AND FLOODWALLS

 15 FLOODWAY CONTROLS AND DIVERSION STRUCTURES

 16 BANK STABILIZATION

 18 CULTURAL RESOURCE PRESERVATION

 30 PLANNING, ENGINEERING & DESIGN

 31 CONSTRUCTION MANAGEMENT



 The ARTM project is currently at a feasibility study design phase with a

Recommended Plan (RP) after considering several alternatives.

3.2 USACE Risk Analysis Process

The risk analysis process follows the USACE Headquarters requirements as well as the

guidance provided by the Cost Engineering Directory of Expertise for Civil Works (Cost

Engineering DX). The risk analysis process reflected within the risk analysis report

uses probabilistic cost and schedule risk analysis methods within the framework of the

Crystal Ball software. The risk analysis results are intended to serve several functions,

one being the establishment of reasonable contingencies reflective of an 80 percent

confidence level to successfully accomplish the project work within that established

contingency amount. Furthermore, the scope of the report includes the identification

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and communication of important steps, logic, key assumptions, limitations, and

decisions to help ensure that risk analysis results can be appropriately interpreted.

Risk analysis results are also intended to provide project leadership with contingency

information for scheduling, budgeting, and project control purposes, as well as provide

tools to support decision making and risk management as the project progresses

through planning and implementation. To fully recognize its benefits, cost and schedule

risk analyses should be considered as an ongoing process conducted concurrent to,

and iteratively with, other important project processes such as scope and execution plan

development, resource planning, procurement planning, cost estimating, budgeting, and

scheduling.

In addition to broadly defined risk analysis standards and recommended practices, the

risk analysis is performed to meet the requirements and recommendations of the

following documents and sources:

 ER 1110-2-1150, Engineering and Design for Civil Works Projects.

 ER 1110-2-1302, Civil Works Cost Engineering.

 ETL 1110-2-573, Construction Cost Estimating Guide for Civil Works.

 Cost and Schedule Risk Analysis Process guidance prepared by the

USACE Cost Engineering DX.

 Memorandum from Major General Don T. Riley (U.S. Army Director of

Civil Works), dated July 3, 2007.

 Engineering and Construction Bulletin issued by James C. Dalton, P.E.

(Chief, Engineering and Construction, Directorate of Civil Works), dated

September 10, 2007.

4. METHODOLOGY/PROCESS

The ARTM Team consists of a Civil Engineer, Geotechnical Engineer, Hydraulic

Engineer, Structural Engineer, Cost Engineer, Hydraulic Modeler, Planning and Policy

member, Environmental members, Real Estate, HTRW members, project managers,

and oversight team members. Team members who took part in the risk analysis

process include the Project Manager, Real Estate, Environmental member, Cost

Engineer, and Hydraulic Engineer/Technical Manager. The ARTM study started in

January 2009 and will conclude in December of 2010.

The MCASES detailed cost estimate and the construction schedule have successfully

passed an Agency Technical Review (ATR). As such, the risk analysis outcome is

based upon an approved product and has passed an ATR.

The risk analysis process for this study is intended to determine the probability of

various cost outcomes and quantify the required contingency needed in the cost

estimate to achieve any desired level of cost confidence. A parallel process is also

used to determine the probability of various project schedule duration outcomes and

quantify the required schedule contingency (float) needed in the schedule to achieve

any desired level of schedule confidence.

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In simple terms, contingency is an amount added to an estimate (cost or schedule) to

allow for items, conditions, or events for which the occurrence or impact is uncertain

and that experience suggests will likely result in additional costs being incurred or

additional time being required. The amount of contingency included in project control

plans depends, at least in part, on the project leaderships willingness to accept risk of

project overruns. The less risk that project leadership is willing to accept the more

contingency should be applied in the project control plans. The risk of overrun is

expressed, in a probabilistic context, using confidence levels.

The Cost Engineering DX guidance for cost and schedule risk analysis generally

focuses on the 80-percent level of confidence (P80) for cost contingency calculation. It

should be noted that use of P80 as a decision criteria is a risk adverse approach

(whereas the use of P50 would be a risk neutral approach, and use of levels less than

50 percent would be risk seeking). Thus, a P80 confidence level results in greater

contingency as compared to a P50 confidence level.

The risk analysis process uses Monte Carlo techniques to determine probabilities and

contingency. The Monte Carlo techniques are facilitated computationally by a

commercially available risk analysis software package (Crystal Ball) that is an add-in to

Microsoft Excel. Cost estimates are packaged into an Excel format and used directly for

cost risk analysis purposes. Because Crystal Ball is an Excel add-in, the schedules for

each option are recreated in an Excel format from their native format. The level of detail

recreated in the Excel-format schedule is sufficient for risk analysis purposes that reflect

the established risk register, but generally less than that of the native format.

The primary steps, in functional terms, of the risk analysis process are described in the

following subsections. The key assumptions in the ARTM risk analysis are provided in

section 5. The risk analysis results are provided in section 6.

4.1 Identify and Assess Risk Factors

Identifying the risk factors via the PDT are considered a qualitative process that results

in establishing a risk register that serves as the document for the further study using the

Crystal Ball risk software. Risk factors are events and conditions that may influence or

drive uncertainty in project performance. They may be inherent characteristics or

conditions of the project or external influences, events, or conditions such as weather or

economic conditions. Risk factors may have either favorable or unfavorable impacts on

project cost and schedule.

Checklists or historical databases of common risk factors are sometimes used to

facilitate risk factor identification. However, key risk factors are often unique to a project

and not readily derivable from historical information. Therefore, input from the entire

PDT is obtained using creative processes such as brainstorming or other facilitated risk

assessment meetings. In practice, a combination of professional judgment from the

PDT and empirical data from similar projects is desirable and is considered.

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A formal PDT meeting was held at the RAY Building in St. Louis, Missouri, for the

purpose of identifying and assessing risk factors. The meeting on March 1, 2010

included the Project Manager, Real Estate, Environmental member, Cost Engineer, and

Hydraulic Engineer/Technical Manager Geotechnical Engineer, Cost Engineer, and

Hydraulic Engineer/Technical Manager.

The first half of the formal meeting focused on risk factor identification using

brainstorming techniques and some facilitated discussions based on risk factors

common to projects of similar scope and geographic location. The second half of the

formal meeting focused on risk factor assessment and quantification.

Additionally, numerous calls and informal meetings were conducted throughout the risk

analysis process on an as-needed basis to further facilitate risk factor identification,

market analysis, and risk assessment.

4.2 Quantify Risk Factor Impacts

The quantitative impacts of risk factors on project plans are analyzed using a

combination of professional judgment, empirical data, and analytical techniques. Risk

factor impacts are quantified using probability distributions (density functions), because

risk factors are entered into the Crystal Ball software in the form of probability density

functions.

Similar to the identification and assessment process, risk factor quantification involves

multiple project team disciplines and functions. However, the quantification process

relies more extensively on collaboration between cost engineering, designers, and risk

analysis team members with lesser inputs from other functions and disciplines.

The following is an example of the PDT quantifying risk factor impacts by using an

iterative, consensus-building approach to estimate the elements of each risk factor:

 Maximum possible value for the risk factor.

 Minimum possible value for the risk factor.

 Most likely value (the statistical mode), if applicable.

 Nature of the probability density function used to approximate risk factor

uncertainty.

 Mathematical correlations between risk factors.

 Affected cost estimate and schedule elements.

In this example, the risk discussions focused on the various project features as

presented within the USACE Civil Works Work Breakdown Structure for cost accounting

purposes. It was recognized that the various features carry differing degrees of risk as

related to cost, schedule, design complexity, and design progress. The example

features under study are presented in Table 1:

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Table 1. Work Breakdown Structure by Feature

01 LANDS AND DAMAGES

02 RELOCATIONS

08

ROADS, RAILROADS, AND

BRIDGES

09 CHANNELS AND CANALS

11 LEVEES AND FLOODWALLS

15

FLOODWAY CONTROL &

DIVERSION STRUCTURES

16 BANK STABILIZATION

18

CULTURAL RESOURCE

PRESERVATION

30

PLANNING, ENGINEERING &

DESIGN

31 CONSTRUCTION MANAGEMENT

The resulting product from the PDT discussions is captured within a risk register as

presented in section 6 for both cost and schedule risk concerns. Note that the risk

register records the PDTs risk concerns, discussions related to those concerns, and

potential impacts to the current cost and schedule estimates. The concerns and

discussions are meant to support the teams decisions related to event likelihood,

impact, and the resulting risk levels for each risk event.

4.3 Analyze Cost Estimate and Schedule Contingency

Contingency is analyzed using the Crystal Ball software, an add-in to the Microsoft

Excel format of the cost estimate and schedule. Monte Carlo simulations are performed

by applying the risk factors (quantified as probability density functions) to the

appropriate estimated cost and schedule elements identified by the PDT.

Contingencies are calculated by applying only the moderate and high level risks

identified for each option (i.e., low-level risks are typically not considered, but remain

within the risk register to serve historical purposes as well as support follow-on risk

studies as the project and risks evolve).

For the cost estimate, the contingency is calculated as the difference between the P80

cost forecast and the base cost estimate. Each option-specific contingency is then

allocated on a civil works feature level based on the dollar-weighted relative risk of each

feature as quantified by Monte Carlo simulation. Standard deviation is used as the

feature-specific measure of risk for contingency allocation purposes. This approach

results in a relatively larger portion of all the project feature cost contingency being

allocated to features with relatively higher estimated cost uncertainty.

For schedule contingency analysis, the option schedule contingency is calculated as the

difference between the P80 option duration forecast and the base schedule duration.

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These contingencies are then used to calculate the time value of money impact of

project delays that are included in the presentation of total cost contingency in section 6.

The resulting time value of money, or added risk escalation, is then added into the

contingency amount to reflect the USACE standard for presenting the total project cost

for the fully funded project amount.

Schedule contingency is analyzed only on the basis of each option and not allocated to

specific tasks. Based on Cost Engineering DX guidance, only critical path and near

critical path tasks are considered to be uncertain for the purposes of contingency

analysis.

5. KEY ASSUMPTIONS

To complete the schedule analysis, it was assumed that the planning, engineering, and

design phase of the project would last one year, allowing the first phase of construction

to start in 2012. This assumption also affects the cost estimate escalation amount

used. In the cost analysis & estimate, it was assumed that the project would be

constructed under multiple contracts with a prime contractor and multiple

subcontractors.

The cost estimate and risk analysis have not undergone an ATR review to date. As

such, the risk analysis is based on the current detailed cost estimate for the

Recommended Plan.

The risk analysis studied the high and moderate impact levels for the activities listed on

the risk register. The low impact level activities were not studied because of the

minimal impact of the activities on the cost or schedule duration.

6. RISK ANALYSIS RESULTS

The following sections discuss the risk register, cost risk analysis results, schedule risk

analysis results, and the combined cost and schedule risk analysis results.

6.1 Risk Register

A risk register is a tool commonly used in project planning and risk analysis and serves

as the basis for the risk studies and Crystal Ball risk models. A summary risk register

that includes the risk events studied in the ARTM Risk analysis is shown in Table 2

below. The risk register reflects the results of risk factor identification and assessment,

risk factor quantification, and contingency analysis. A more detailed risk register is

provided in appendix A. The detailed risk register in appendix A include low level and

unrated risks, as well as additional information regarding the specific nature and

impacts of each risk.

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Table 2. Studied Risk Register

It is important to note that a risk register can be an effective tool for managing identified

risks throughout the project life cycle. As such, it is generally recommended that risk

registers be updated as the designs, cost estimates, and schedule are further refined,

especially on large projects with extended schedules. Recommended uses of the risk

register going forward include:

PDT Discussions Likelihood* Impact* Risk Level*

(Internal Risk

Items are those PROJECT &

PROGRAM

MGMT

PPM-1 Congressional Funding

The concern is that the PED and Construction funding is

uncertain, post feasibility

The current selected plan exceeds the congressional

funding authorization. Funding may be delayed as another

authorization will need to occur. Likely Marginal Moderate

PPM-4 Accelerated Feasibility Schedule

Feasibility study has been delivered on an accelerated

project schedule

Due to the accelerated schedule, a project item may have

been overlooked that could impact the project cost or

schedule Likely Significant High

PPM-5 Local Agency Issues

Concern if local sponsor (state) is able to produce their

funding contribution

Six LCA projects will require their funding contributions

from the state at roughly the same time Unlikely Critical Moderate

PPM-6 Priority Issues Congressional priorities may change

Completion of the LCA projects may drop down on

Congress's priority list, which could delay funding to the

project or require design changes. Likely Significant High CONTRACT

ACQUISITION

RISKS

CA-2 Numerous Separate Contracts

The plan has 59 elements which could be divided into

separate contracts

the cost estimate, several separate contracts could

potentially increase mob & Demob costs and affect unit

prices for the project. Likely Marginal Moderate

TECHNICAL

RISKS

TL-1 Feasibility Level Design Design assumptions were based on existing data

Little new data was used for design on the project. Exiting

data in the project area was used for the design

assumptions Likely Marginal Moderate

TL-3 Geotech Borings

Borings were used in the geotech that were not at the exact

feature location

While some borings were located at the feature locations,

others were not which could result in differing site

conditions affecting design & project scope. Likely Marginal Moderate

TL-4 Structural Quantities

Changes in the Geotech analysis could affect the structure

foundations

If site conditions differ greatly from the borings used, piling

quantities used for foundation work could increase or

decrease Likely Marginal Moderate LANDS AND

DAMAGES

RISKS

LD-3 Utilities The project may encounter unknown pipelines in the marsh.

The unknown pipelines will have cost impacts to the project

depending on who is responsible for the cost to relocate

the pipelines. Likely Marginal Moderate REGULATORY

AND

ENVIRONMENT

RE-1

Environmental & Water Quality

Issues

Water quality issues related to salinity and impacts on

oysters/fisheries.

Concerns by local commercial fishing/oyster interests

could delay implementation of the project. Likely Marginal Moderate

RE-3

Cultural Sites, Endangered

species, & wetlands

There is potential for discovery of culturally significant sites

throughout project area.

Discovery of site(s) could impact schedule by delaying

construction. Likely Marginal Moderate

CONSTRUCTION

RISKS

CON-1 Contract Modifications

There may be modification issues that have not been

captured in current risks

Modifications could be issued for remobilizations, delays,

and quantity assumptions Likely Marginal Moderate ESTIMATE AND

SCHEDULE

RISKS

EST-1 Berm Productivity

The containment berm productivity could greatly affect the

estimate

The productivity assumptions can vary due to various

possibilities, affecting the schedule & estimate Unlikely Significant High

EST-2

Culvert Construction

Productivity

The culvert construction productivity could affect the

estimate & schedule

The productivity assumptions can vary due to various

possibilities, affecting the schedule & estimate Unlikely Marginal Moderate

EST-3 Dredging Productivity

Dredge estimating program assumes a certain productivity

based on dredge size. Productivity may vary.

The productivity assumptions can vary due to various

possibilities, affecting the schedule & estimate Unlikely Significant High

EST-4 Fuel Fuel Fluctuations can impact marine and land based costs.

Fuel is a major cost driver on dredging projects and has

fluctuated greatly in the past 2 years. Likely Significant High Programmatic

Risks (External

Risk Items are

PR-1 Acts of God Severe weather may impact cost or schedule

Hurricanes or strong storms could impact construction or

cause the need for rework. Milder weather conditions have

been addressed with a productivity markup in the estimate. Likely Critical High

PR-2 Market Conditions

Market conditions and competing projects may affect bid

competition & equipment availability

Currently, 6 other LCA marsh restoration projects are

planned and there are a limited number of dredges

available for the marsh area. Likely Significant High

PR-3 Community Objections Public objections may delay project

The public perceives the project as having induced

flooding, some features are in urban areas, and disruption

of oyster harvesting could have political implications Likely Marginal Moderate

PR-4 Stakeholders Stakeholders have differing opinions of the project size.

Some stakeholders would prefer a larger project and some

stakeholders would prefer a smaller project. Objections to

the project size could cause a delay Likely Marginal Moderate

Project Cost

Risk No. Risk/Opportunity Event Concerns

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 Documenting risk mitigation strategies being pursued in response to the

identified risks and their assessment in terms of probability and impact.

 Providing project sponsors, stakeholders, and leadership/management with

a documented framework from which risk status can be reported in the

context of project controls.

 Communicating risk management issues.

 Providing a mechanism for eliciting risk analysis feedback and project

control input.

 Identifying risk transfer, elimination, or mitigation actions required for

implementation of risk management plans.

In simple terms, a correlation is a dependency that exists between two risks and may be

direct or indirect. An indirect correlation is one in which large values of one risk are

associated with small values of the other. Indirect correlations have correlation

coefficients between 0 and -1. A direct correlation is one in which large values of one

risk are associated with large values of the other. Direct correlations have correlation

coefficients between 0 and 1.

Correlations are important to understand the logic used in the risk analyses. The

mathematical correlations used in the Monte Carlo simulations are as follows:

 Present any risk event correlations, addressing their relationships.

 Present the final risk register or the condensed version. At a minimum

include those risk events studied (an appendix can include the complete risk

register):

 Risk event identifying number.

 Risk or opportunity event.

 PDT concerns.

 PDT discussions.

 Project cost likelihood, impact, and risk level.

 Project schedule likelihood, impact, and risk level,

6.2 Cost Risk Analysis - Cost Contingency Results

A cost risk analysis was conducted on the twenty risks on the risk register, shown in

Appendix A, which had a cost impact of moderate or high. The risk was analyzed using

the low, most likely, and high estimates for each risk item and the items associated

variance distribution. The analysis produced a sensitivity chart of the risk items and

confidence levels from 0 to 100% and the associated contingency amount.

The cost sensitivity chart is shown in Figure 1 below. The sensitivity chart shows the

influence of each risk items on the resulting cost contingency. The risk items are

ranked according to their importance to the cost contingency. As shown in the Cost

Sensitivity Chart, the Market Conditions item had the most influence on the cost

contingency. The items that had the least amount of influence on the cost contingency

are:

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 Accelerated Feasibility Schedule

 Geotech Borings

 Dredging Productivity

 Structural Quantities

 Berm Productivity

 Other Risk Items

Figure 1. Cost Sensitivity Chart

The cost risk analysis also produced a confidence table in ten percent increments of

project confidence associated with contingency dollars. The confidence table is shown

in Table 3 below. As seen in the table, all but one of the associated contingency dollar

amounts is positive. The contingency dollar amounts range from just over negative $25

million to well over $99 million. The recommended cost contingency amount is

$51,103,260.

Table 3. Cost Confidence Table

Confidence

Level

Contingency

($)

0% ($25,191,648)

10% $14,077,767

20% $21,146,527

30% $26,524,147

40% $31,197,091

50% $35,666,274

60% $40,224,992

70% $45,238,159

80% $51,103,261

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90% $58,917,830

100% $99,904,260

From the table, a confidence curve was also established that shows the relationship of

percent confidence with contingencies in dollars. That curve is shown in Figure 2. As

seen in the curve, the contingency amount increased sharply between confidence levels

0% and 10% as well as levels 90% to 100%. All of the other confidence levels show a

steady increase in the contingency amount.

Figure 2. Cost Confidence Curve

6.3 Schedule Risk Analysis - Schedule Contingency Results

A schedule risk analysis was conducted on the twenty-one risks on the risk register,

shown in Appendix A, which had a schedule impact of moderate or high. The risk was

analyzed using the low, most likely, and high estimates for each risk item and the items

associated variance distribution. The analysis produced a sensitivity chart of the risk

items and confidence levels from 0 to 100% and the associated contingency amount.

The schedule sensitivity chart is shown in Figure 3 below. The sensitivity chart shows

the influence of each risk items on the resulting schedule contingency. The risk items

are ranked according to their importance to the schedule contingency. As shown in the

Schedule Sensitivity Chart, the Dredging Productivity item had the most influence on the

($40,000,000)

($20,000,000)

$0

$20,000,000

$40,000,000

$60,000,000

$80,000,000

$100,000,000

$120,000,000

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Contingency ($)

Confidence Level

Cost Confidence

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schedule contingency. The items that had the least amount of influence on the

schedule contingency are:

 Accelerated Feasibility Schedule

 Ancillary Owner Rights

 Acts of God

 Unknown Utilities

 Records/inaccuracies

 Local Agency Issues

 Contract Modifications

 Cultural Sites, Endangered Species, & Wetlands

 Numerous Separate Contracts

 Other items

Figure 3. Schedule Sensitivity Chart

The schedule risk analysis also produced a confidence table in ten percent increments

of project confidence associated with contingency months. The confidence table is

shown in Table 4 below. As seen in the table, all but one of the associated contingency

month amounts are positive. The contingency month amounts range from negative

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seven months to over eight years. The recommended schedule contingency amount is

58 months.

Table 4. Schedule Confidence Table

Confidence

Level

Contingency

(mo)

0% (7)

10% 29

20% 35

30% 39

40% 43

50% 46

60% 50

70% 53

80% 58

90% 63

100% 100

From the table, a confidence curve was also established that shows the relationship of

percent confidence with contingencies in months. That curve is shown in Figure 4. As

seen in the curve, the contingency amount increased sharply between confidence levels

0% and 10% as well as levels 90% to 100%. All of the other confidence levels show a

steady increase in the contingency amount.

Figure 4. Schedule Confidence Curve

(20)

0

20

40

60

80

100

120

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Contingency (mo)

Confidence Level

Schedule Confidence

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6.4 Combined Cost and Schedule Contingency Results

The cost and schedule risk analysis resulted in a recommended cost contingency of

$51,103,261 and a schedule recommended contingency of 58 months. To obtain the

overall project contingency, the cost risk analysis confidence table and the schedule risk

analysis confidence table are combined. That combined table is shown in Table 5. To

obtain the final contingency dollar amount, the schedule contingency is converted from

months into dollars by using the time value of money.

Table 5. Combined Confidence Table

Confidence

Level

Contingency

($)

Contingency

(mo)

0% ($25,191,648) (7)

10% $14,077,767 29

20% $21,146,527 35

30% $26,524,147 39

40% $31,197,091 43

50% $35,666,274 46

60% $40,224,992 50

70% $45,238,159 53

80% $51,103,261 58

90% $58,917,830 63

100% $99,904,260 100

7. MAJOR FINDINGS/OBSERVATIONS

The cost and schedule risk analysis resulted in a recommended cost contingency of

$51,103,261 and a schedule recommended contingency of 58 months. Those two

results are combined to produce a total project contingency. The total project

contingencies for confidence levels 0 to 100% are shown below. Table 6 presents

project contingencies, which include base cost plus cost and schedule contingencies.

Figure 5 illustrates the total project cost risk analysis in confidence curve. The

recommended total project contingency is 34%, or $68,353,130, based on the 80%

confidence level. This contingency was applied to the detailed estimate for the

Recommended Plan for the ARTM project.

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Table 6. Project Contingencies (Base Cost Plus Cost and Schedule

Contingencies)

Confidence

Level Project Cost

Contingency

($)

Contingency

(%)

0% $171,000,832 ($27,273,529) -14%

10% $220,977,063 $22,702,702 11%

20% $229,830,292 $31,555,931 16%

30% $236,297,559 $38,023,198 19%

40% $242,260,148 $43,985,787 22%

50% $247,621,533 $49,347,172 25%

60% $253,369,930 $55,095,569 28%

70% $259,275,332 $61,000,971 31%

80% $266,627,491 $68,353,130 34%

90% $275,292,118 $77,017,757 39%

100% $327,920,775 $129,646,414 65%

Figure 5. Project Confidence Curve

The risk items that had the most influence on the resulting total project cost contingency

were the Market Conditions and Dredging Productivity items. These items are

discussed in more detail in the Mitigation Recommendations section.

The above risk analysis results are intended to provide project leadership with

contingency information for scheduling, budgeting, and project control purposes, as well

as to provide tools to support decision making and risk management as projects

$0

$50,000,000

$100,000,000

$150,000,000

$200,000,000

$250,000,000

$300,000,000

$350,000,000

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Estimated Project Cost

Confidence Level

Project Cost Risk Analysis

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progress through planning and implementation. These conclusions were reached by

identifying and assessing risk items for use in the risk analysis. These quantitative

impacts of these risk items are then analyzed using a combination of professional

judgment, empirical data, and analytical techniques. The total project cost contingency

is then analyzed using the Crystal Ball software. Monte Carlo simulations are

performed by applying the risk factors (quantified as probability density functions) to the

appropriate estimated cost and schedule elements identified by the PDT.

8. MITIGATION RECOMMENDATIONS

An important outcome of the cost and schedule risk analysis is the communication of

high risk areas which have a high potential to affect the project cost and/or schedule.

For the ARTM project, those risks are the Market Conditions for cost and Dredging

Productivity for the schedule. These two risk items can be mitigated, reducing the risk

of an increased project cost.

To mitigate the risk of the market conditions can be assessed during the planning,

engineering, and design phase of the project to determine the best contract acquisition

date in relation to similar scoped projects. This will enable the PDT to reduce the risks

associated with the market conditions. To reduce the risk of dredging productivity,

detailed productivity studies of similar sized dredges could be completed. After these

studies are complete, the cost engineer will be able to more accurately calculate the

dredging production rate.

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APPENDIX A

DETAILED RISK REGISTERS

Register is split into two parts.

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PDT Discussions Likelihood* Impact* Risk Level*

Rough Order

Impact ($) Likelihood* Impact* Risk Level*

Rough Order

Impact (mo)

Correlation

to Other(s)

PROJECT & PROGRAMMGMT

PPM-1 Congressional Funding

The concern is that the PED and Construction funding is

uncertain, post feasibility

The current selected plan exceeds the congressional funding

authorization. Funding may be delayed as another authorization

will need to occur. Likely Marginal Moderate Likely Marginal Moderate Project Manager Project Cost & Schedule

PPM-2 Regionalized Team The feasibility study was completed by a regionalized team.

Team members not from the New Orleans area were not

familiar with marsh restoration projects before the start of the

project. The PDT is concerned project aspects may have been

left out. Unlikely Marginal Low <1% Unlikely Marginal Low <1%

PPM-3

Coordination &Communication Difficulties

This project was one of the first large scale regionalized

planning projects.

A learning curve was involved for all PDT members at the start

of the project Unlikely Marginal Low <1% Unlikely Marginal Low <1%

PPM-4

Accelerated FeasibilitySchedule

Feasibility study has been delivered on an accelerated project

schedule

Due to the accelerated schedule, a project item may have been

overlooked that could impact the project cost or schedule Likely Significant High Likely Significant High Project Cost & Schedule

PPM-5 Local Agency Issues

Concern if local sponsor (state) is able to produce their funding

contribution

Six LCA projects will require their funding contributions from the

state at roughly the same time Unlikely Critical Moderate Unlikely Critical Moderate Project Sponsor(s) Project Cost & Schedule

PPM-6 Priority Issues Congressional priorities may change

Completion of the LCA projects may drop down on Congress's

priority list, which could delay funding to the project or require

design changes. Likely Significant High Likely Significant High Project Cost & Schedule

CONTRACT ACQUISITIONRISKS

CA-1

Undefined AcquisitionStrategy No acquisition strategy has been defined

Due to the large size of the project, the PDT feels the

acquisition strategy will be unrestricted. Unlikely Marginal Low <1% Unlikely Marginal Low <1% Contracting

CA-2

Numerous SeparateContracts

The plan has 59 elements which could be divided into separate

contracts

While some separate contracts have been considered in the

cost estimate, several separate contracts could potentially

increase mob & Demob costs and affect unit prices for the

project. Likely Marginal Moderate Likely Marginal Moderate Contracting Project Cost & Schedule

TECHNICAL RISKS

TL-1 Feasibility Level Design Design assumptions were based on existing data

Little new data was used for design on the project. Exiting data

in the project area was used for the design assumptions Likely Marginal Moderate Likely Marginal Moderate Technical Lead Project Cost & Schedule

TL-2 Civil Quantities Quantities for berm and culvert construction could vary

The PDT feels that the current quantities will vary very little

during construction Negligible Marginal Low <1% Negligible Marginal Low <1% Geotechnical/Civil Design Project Cost & Schedule

TL-3 Geotech Borings

Borings were used in the geotech that were not at the exact

feature location

While some borings were located at the feature locations,

others were not which could result in differing site conditions

affecting design & project scope. Likely Marginal Moderate Likely Marginal Moderate TL-4 Geotechnical/Civil Design Project Cost & Schedule

TL-4 Structural Quantities

Changes in the Geotech analysis could affect the structure

foundations

If site conditions differ greatly from the borings used, piling

quantities used for foundation work could increase or decrease Likely Marginal Moderate Likely Marginal Moderate TL-3 Structural Design Project Cost & Schedule

TL-5 Mechanical Gates

Some of the gates are very large in size as well as one gate is

an Obermeyer Air Bladder Gate

Large gates are designed as sluice gates, but after talking with a

manufacturer, roller gates were priced for practicality. The Air

Bladder gate requires special labor to assembly which may not

be available in the area Unlikely Marginal Low <1% Unlikely Marginal Low <1% Mechanical Design

TL-6 Dredging

Some pipe runs could be longer than estimated and quantities

could vary.

The PDT feels that only a few pipelines may be longer than

estimated and that the quantities may vary very little during

construction Unlikely Marginal Low <1% Unlikely Marginal Low <1% Geotechnical/Civil Design

Concerns

Contract Risks (Internal Risk Items are those that are generated, caused, or controlled within the PDT's sphere of influence.)

Project Cost Project Schedule

Risk No. Risk/Opportunity Event

Variance

Distribution

Affected Project

Component Responsibility/POC

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LANDS AND DAMAGESRISKS

LD-1 Ancillary owner rights

Several project features are proposed on property having

multiple owners or having ownerships/interests listed as

unknown. Condemnation actions tend to be time-consuming Very Likely Negligible Low <1% Very Likely Significant High 9 Real Estate Project Schedule

LD-2 Records/Inaccuracies

Inaccuracies are anticipated in local land records at some

project sites Curative title actions tend to be time consuming Very Likely Negligible Low <1% Very Likely Marginal Moderate 6 Real Estate Project Schedule

LD-3 Utilities The project may encounter unknown pipelines in the marsh.

The unknown pipelines will have cost impacts to the project

depending on who is responsible for the cost to relocate the

pipelines. Likely Marginal Moderate Likely Marginal Moderate Real Estate Project Cost & Schedule

REGULATORY ANDENVIRONMENTAL RISKS

RE-1

Environmental & WaterQuality Issues

Water quality issues related to salinity and impacts on

oysters/fisheries.

Concerns by local commercial fishing/oyster interests could

delay implementation of the project. Likely Marginal Moderate Likely Significant High 12 Environmental Compliance Project Cost & Schedule

RE-2

Adaptive ManagementFeatures

The project includes several features that may be adaptively

managed.

Necessity of operating structures in unforeseen manner or with

unforeseen frequency could increase costs for local sponsor.This cost risk does not apply to the government estimate and

therefore, will not be studied in the cost or schedule model. Likely Significant High Likely Negligible Low <1% Environmental Compliance Project Cost

RE-3

Cultural Sites, Endangeredspecies, & wetlands

There is potential for discovery of culturally significant sites

throughout project area.

Discovery of site(s) could impact schedule by delaying

construction. Likely Marginal Moderate Likely Significant High 6 Environmental Compliance Project Cost & Schedule

RE-4 Project in a State Park

Several features are located within boundary of or will impact

Pointe au Chien Wildlife Management Area

Unforeseen impacts to WMA could delay project

implementation. Unlikely Negligible Low <1% Unlikely Negligible Low <1% Environmental Compliance

RE-5

Negative CommunityImpacts

Several features will require road to be relocated during project

construction

Unforeseen impacts to traffic could delay construction and/or

increase costs. Likely Negligible Low <1% Likely Negligible Low <1% Environmental Compliance

CONSTRUCTION RISKS

CON-1 Contract Modifications

There may be modification issues that have not been captured

in current risks

Modifications could be issued for remobilizations, delays, and

quantity assumptions Likely Marginal Moderate Likely Marginal Moderate Construction Project Cost & Schedule

CON-2 Site Access & Staging Areas The project site has limited access points and stagin areas.

The site access has been addressed in the cost estimate, but

could affect the project schedule by increasing the time for

transitioning equipment. Staging areas are also limited at the

project site. Some staging may have to occur by barge, which

has been addressed in the project estimate. Likely Negligible Low <1% Likely Significant High Construction Project Schedule

CON-3 Limited Skilled Traes

Skilled labor for certain trades may not be available in the

immediate project area

The PDT feels that contractors will bring in the skilled labor they

need to complete the work, limiting the risk impacts Likely Negligible Low <1% Likely Negligible Low <1% Construction

ESTIMATE ANDSCHEDULE RISKS

EST-1 Berm Productivity

The containment berm productivity could greatly affect the

estimate

The productivity assumptions can vary due to various

possibilities, affecting the schedule & estimate Unlikely Significant High Unlikely Significant High Cost Engineering Project Cost & Schedule

EST-2

Culvert ConstructionProductivity

The culvert construction productivity could affect the estimate &

schedule

The productivity assumptions can vary due to various

possibilities, affecting the schedule & estimate Unlikely Marginal Moderate Unlikely Marginal Moderate Cost Engineering Project Cost & Schedule

EST-3 Dredging Productivity

Dredge estimating program assumes a certain productivity

based on dredge size. Productivity may vary.

The productivity assumptions can vary due to various

possibilities, affecting the schedule & estimate Unlikely Significant High Unlikely Significant High Cost Engineering Project Cost & Schedule

EST-4 Fuel Fuel Fluctuations can impact marine and land based costs.

Fuel is a major cost driver on dredging projects and has

fluctuated greatly in the past 2 years. Likely Significant High Likely Negligible Low Cost Engineering Project Cost & Schedule

PR-1 Acts of God Severe weather may impact cost or schedule

Hurricanes or strong storms could impact construction or cause

the need for rework. Milder weather conditions have been

addressed with a productivity markup in the estimate. Likely Critical High Likely Critical High Project Cost & Schedule

PR-2 Market Conditions

Market conditions and competing projects may affect bid

competition & equipment availability

Currently, 6 other LCA marsh restoration projects are planned

and there are a limited number of dredges available for the

marsh area. Likely Significant High Likely Significant High Project Cost & Schedule

PR-3 Community Objections Public objections may delay project

The public perceives the project as having induced flooding,

some features are in urban areas, and disruption of oyster

harvesting could have political implications Likely Marginal Moderate Likely Significant High Project Cost & Schedule

PR-4 Stakeholders Stakeholders have differing opinions of the project size.

Some stakeholders would prefer a larger project and some

stakeholders would prefer a smaller project. Objections to the

project size could cause a delay Likely Marginal Moderate Likely Significant High Project Cost & Schedule

Programmatic Risks (External Risk Items are those that are generated, caused, or controlled exclusively outside the PDT's sphere of influence.)

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APPENDIX Q:

Recreation Incidental Benefits

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Volume III

APPENDIX Q:

Recreation Incidental Benefits

Table of Contents

Q1.1 Introduction and Methodology ......................................................................... 2

Q2.1 Project and Study Area Characteristics........................................................... 2

Q3.1 Estimating Recreational Use Using Louisiana Data ....................................... 4

Q4.1 Recreational Benefits ......................................................................................... 8

Q5.1 References ......................................................................................................... 10

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Volume III

APPENDIX Q:

Recreation Incidental Benefits

Convey Atchafalaya River Water to Northern Terrebonne Marshes

and Multipurpose Operation of Houma Navigation Lock

Draft Feasibility Report

Q1.1 Introduction and Methodology

This report summarizes the potential incidental recreation benefits of the Convey

Atchafalaya River Water to Northern Terrebonne Marshes (ARTM) Project, which will

consist of features to increase the flow of freshwater into the marshes in Terrebonne,

Lafourche, and St. Mary Parishes. The ARTM Study Area is east of the Atchafalaya

River, south of the Gulf Intracoastal Waterway, and west of Bayou Lafourche. The

project is primarily in Terrebonne Parish, Louisiana, although depending on the

alternative implemented, some features may be located further east in Lafourche Parish

or to the west in St. Mary Parish.

ER 1105-2-100 Appendix E authorizes the use of three methods to estimate the economic

benefits of recreation. These methods are the contingent valuation method, the travel cost

method, and the unit day value method. The first two methods require extensive data that

are not readily available for the ARTM Project. The unit day value method is the simplest

method and is appropriate for this study of the ARTM Project. The incidental recreation

benefits are estimated as required by EP 1165-2-502.

Annually, Headquarters USACE publishes unit day values for both specialized recreation

and general recreation. The term general recreation refers to an area that provides

access to a variety of recreational activities, is widely used, and provides supportive

facilities, such as marinas. Specialized refers to an area for which opportunities are

limited and intensity of use is low. Similar hunting and fishing areas are available

throughout southern Louisiana, in areas directly adjacent to the study area. Primarily

because of the availability of similar recreational opportunities in nearby areas, the

general recreation unit day values are used. The unit day values in this analysis are

published in Economic Guidance Memorandum Number 10-03 (EGM 10-03).

Q2.1 Project and Study Area Characteristics

Several alternatives for the ARTM Project are being considered. The features in each

alternative are designed to bring additional freshwater to the marshes in the project area.

These are:

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Alternative 1: No Action. For this alternative, no Atchafalaya conveyance measures

will be implemented. The future condition will include sea level rise and continued

subsidence. Other projects that are planned or under construction or are likely to be

implemented include many smaller environmental restoration efforts planned under

the Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA).

Alternative 2: Utilize Flow Management Measures to Maximize Benefits of Existing

Freshwater Flows. This strategy will eliminate GIWW constrictions and construct

flow management features in the interior portions of the project area. This alternative

will attempt to redistribute the existing inputs to more efficiently utilize fresh water.

Alternative 3: Increase Atchafalaya River Inflows and Utilize Flow Management

Measures to Maximize Restoration Efforts. This strategy will increase the supply of

freshwater from the Atchafalaya River in addition to more efficiently distributing

existing flows. The inflow from the Atchafalaya River will be achieved by

developing an opening through Avoca Island.

Alternative 4: Utilize Pump at Grand Bayou and Flow Management Measures to

Maximize Restoration Efforts. This strategy will utilize existing GIWW freshwater

flows from the west and drawing freshwater from the east by utilizing a pump at

Grand Bayou in addition to constructing flow management features in the interior

portions of the project area. The Grand Bayou pump would only increase freshwater

delivery to the Grand Bayou watershed.

Alternative 5: Increase Atchafalaya River Inflows, Utilize Pump at Grand Bayou,

and implement Flow Management Measures to Maximize Restoration Efforts. This

strategy will include maximizing flow inputs from both the Atchafalaya River and

locations east of the Project Area along with flow management features.

Alternative 6: Increase Atchafalaya River Inflows with No Flow Management

Measures. This strategy is similar to Alternative 3 without the flow management

measures and will include maximizing flow inputs from the Atchafalaya River,

removing GIWW constrictions, and improving flows from the GIWW to Grand

Bayou but will not include any other flow management features.

Alternative 7: Utilize modified operation of the Houma Navigation Canal Lock

Complex to distribute freshwater and prevent saltwater intrusion.

Alternative 8: Utilize Flow Management Measures to Maximize Benefits of Existing

Freshwater Flows in Central and Eastern Sub-Areas. Alternatives developed under

this strategy will focus on constructing flow management features in the interior

portions of the Central and Eastern project areas. Additional freshwater will not be

introduced from other sources. Instead, this alternative will attempt to redistribute the

existing inputs to more efficiently utilize fresh water in the Central and Eastern areas.

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The ARTM area is largely comprised of several fishing communities and the City of

Houma. The Terrebonne Parish Recreation Department manages many recreational

facilities within the City of Houma, such as swimming pools, ball fields, and

gymnasiums, and, as these would not be impacted by the alternatives, they are not

considered in this analysis. The primary recreational activities impacted by the

alternatives are consumptive activities, fishing and hunting, which generally require a

boat for access. There is also non-consumptive use of wildlife, such as bird watching.

Dominant recreational fishing species are speckled trout and red drum. Hunting consists

of waterfowl hunting, deer hunting and snipe hunting, with waterfowl hunting the

dominant activity. Bird watching, fishing, and hunting are considered in this analysis.

Q3.1 Estimating Recreational Use Using Louisiana Data

There are several appropriate sources of data from which to estimate the number of

recreational users in the study area.

For fishing and hunting, the number of licenses issued in the four parishes around the

study area provides a basis for determining local use. Most of Terrebonne Parish is within

the study area. Only small portions of St. Mary, Assumption, and Lafourche Parishes are

within the study area, but a significant portion of participants from these parishes are

expected to use the ARTM Study Area as distances are not great.

Additional data about fishing and hunting is found in the Statewide Comprehensive

Outdoor Recreation Plan (SCORP), which is published every five years by the Office of

State Parks within the Louisiana Department of Culture Recreation and Tourism. The

SCORP is based upon in-field and telephone surveys and is used to prioritize the funding

of recreation facilities within the state and is prepared to comply with National Park

Service guidelines. The 2003-2008 SCORP contains more detailed information and more

regional information than the 2009-2013 SCORP, and these data are used in this analysis.

The 2003-2008 SCORP estimates the number of recreational fishermen in Terrebonne

Parish and the surrounding parishes. The 2003-2008 SCORP explains a facility use

standard based upon a turnover of 20 boats per boat ramp daily, with three persons per

boat. Hunting facility use is based upon a turnover of 1 hunter for every 25 acres per day.

The 2009-2013 SCORP does not have a facility standard for saltwater boat ramps, but

does provide a standard for freshwater boat ramps of one boat ramp per population of

3,200.

The most recent SCORP states that fishing and hunting are both declining recreational

activities and specifies that fishing activity declined 20% since the last SCORP.

However, according to the 2009-2014 SCORP, the region of the State that includes the

Atchafalaya Basin has the highest percentage of population that fish (80.5%). According

to the 2003-2008 SCORP, this region also has the highest number of activity days fishing

from a boat (22.3 days).

Estimate of Unit Day Values

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The estimates of annual use are combined with unit day values to estimate annual

recreation benefits. Unit day values were estimated using the most recent values available

in EGM 10-03.

The Unit Day Value method involves assigning points in each of five categories or

criteria. The five criteria are:

Recreation Experience: the number of high quality recreational activities possible in

the area;

Availability of Opportunity: the availability of similar opportunities nearby. For

fishing and hunting this is the likelihood of fishing and hunting success;

Carrying Capacity: the degree to which an area provides services to support

recreation;

Accessibility: the degree to which the area is readily accessible; and

Environmental Quality: the aesthetic qualities of the area including water and

vegetation, air and water quality, scenery, and climate.

Points were assigned for each of these five criteria. The determination of points for each

criterion is described below. Two of the five criteria are impacted by the project.

A maximum of 30 points may be assigned for this criterion. Point values to be assigned

are described in the following table:

Recreation Experience

Recreation Experience

Description Two general

activities

available

Several

general

activities

available

Several

general

activities

available

with one

high

quality

Several

general

activities

available,

more than

one

high

quality

Numerous

high

quality

activities

available

Range of Points 0 - 4 5 -10 11 - 16 17 - 23 24 - 30

For this analysis, 23 points are assigned for all alternatives because there are three

excellent activities, wildlife watching, fishing and hunting, in the study area. Fishing is a

year-round activity and consists primarily of fishing for speckled trout and red drum.

There is also some recreational crabbing with traps and shrimp harvesting with nets, but

these are primarily commercial activities. These activities are included with fishing when

estimating benefits because the alternatives will have the same impact on all of these

activities.

The primary hunting season is limited to two months per year for duck hunting. Other

types of hunting occur in a limited way on higher elevations within the study area,

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consumptive activity in the area. This activity has a limited number of nonresident

participants and few local residents make trips for wildlife watching. The few open

waterways in the study area do not lend themselves to pleasure boating or water skiing.

There is no significant hiking in the study area. Camping is directly related to fishing and

occurs primarily in raised structures maintained specifically for recreational fishermen.

A maximum of 18 points may be assigned for this criterion. Point values to be assigned

are described in the following table:

Availability of Opportunity and Likelihood of Fishing Success

Availability of Opportunity

Description Several

similar

opportunities

within one

hour

and a few

within 30 min

travel time

Several

similar

opportunities

within one

hour but

none within

30 min

travel time

One or

two

within

one hour

travel

time but

none

within 45

min

No similar

opportunities

within one

hour travel

time

No similar

opportunities

within two

hour travel

time

Range of

Points

0 - 3 4 - 6 7 - 10 11 - 14 15 - 18

Availability of Opportunity is equated with likelihood of success at fishing and hunting,

as stated in Table 2 of EGM 10-03, and is impacted by the alternatives. Fishing success is

defined as catching the species sought, and the primary saltwater species sought are

speckled trout and red drum. In the near term, as the alternatives are implemented,

recreational fishermen seeking those species will most likely need to move southward

within the study area. However the primary freshwater species sought, largemouth bass,

will most likely become more prevalent in the fresher portions of the study area. During

the focus group meeting a consensus opinion was stated that the ARTM study area was

large enough that recreational fishermen will have ample opportunity to move within the

study area to find speckled trout and red drum. Over time, as the project alternatives

improve the ecosystem, the likelihood of fishing success for all recreational fishermen is

expected to increase.

The likelihood of hunting success is defined similarly and the likelihood of success is

similarly very high. Therefore, 14 points are assigned for the base year.

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Carrying Capacity

A maximum of 14 points may be assigned for this criterion. Point values to be assigned

are described in the following table:

Carrying Capacity

Description Minimum

facility

development

for public

health and

safety

Basic

facilities

to conduct

activity

Adequate

facilities

to conduct

activity

Optimum

facilities

to conduct

activity

Ultimate

facilities

to conduct

activity

Range of Points 0 - 2 3 - 5 6 - 8 9 - 11 12 - 14

For this analysis, 10 points are assigned because there are adequate facilities supporting

fishing, hunting, and wildlife observation. The facilities are both publicly- and privatelyowned. Representatives of the privately-owned facilities that participated in the focus

group meetings stated that their facilities will likely remain commercially viable under all

alternatives. The public facilities are at the state and federal wildlife refuges.

Accessibility

A maximum of 18 points may be assigned for this criterion. Point values to be assigned

are described in the following table:

Accessibility

Description Limited Access

by any means

to site

Fair access

to site;

limited

access

within site

Fair access

to site; fair

access

within site

Good

access to

site; fair

access

within site

Good

access to

site; good

access

within site

Range of Points 0 - 3 4 - 6 7 - 10 11 - 14 15 - 18

For this analysis, 11 points are assigned. The study area contains a large portion of

Terrebonne Parish and there are excellent highways within the study area and there are

roadways providing access to the major waterways. These waterways then provide access

for sportsmen with boats to the entire study area.

Environmental

A maximum of 20 points may be assigned for this criterion. Point values to be assigned

are described in the following table:

Environmental

Description Low aesthetic

factors

Average

aesthetic

factors

Above

average

esthetic

factors

High

aesthetic

factors

Outstanding

aesthetic

factors

Range of Points 0 - 2 3 - 6 7 - 10 11 - 15 16 - 20

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Aesthetic factors are impacted by the alternatives. Specifically, water quality and

vegetation will be impacted by the alternatives. However, the long-term effect of

diversion of freshwater into the wetlands is that the vegetation and supported wildlife

habitat will be sustained. Therefore, 15 points are assigned for this criterion for the base

year.

Thus, the total number of points assigned to the proposed Atchafalaya conveyance

project for the first year of implementation is 73.

Q4.1 Recreational Benefits

EGM 10-03 provides a table showing how to relate points assigned using the five criteria

to dollar values. Since this project was evaluated to have a total of 73 points, using linear

interpolation and the values provided by EGM 10-03 for either 70 or 80 points, we assign

a dollar value of $9.72 as the general recreation unit day value for the base year.

Given that the area has 665,020 unit days per year and that each unit day is valued at

$9.72, the total annual monetary value of the recreational resource that would be affected

by the ARTM project is $6,464,657. Given that the likelihood of success with fishing will

increase and that environmental factors will improve over time if the proposed project is

implemented, the total annual monetary value of the recreational resource will increase in

the future compared to the annual monetary value of the recreational resource should the

proposed project not be implemented.

To better understand the economic impact of the proposed project on recreation, the

analysis considered effects over a 50-year period. The analysis uses the Federal discount

rate for FY 2010 of 0.04625. The following table summarizes the potential net present

value of the proposed project for each alternative showing that the proposed project will

benefit recreational opportunities.

Net Increase / Decrease in Incidental Recreation Benefits

Without

Project

Alternative

2

Alternative

3

Alternative

4

Alternative

5

Alternative

6

Alternative

7

Alternative

8

Net

Present

Value

$0 $2,077,000 $2,799,000 $1,588,000 $1,505,000 $252,000 $190,000 $2,057,000

Annualized $0 $102,505 $138,137 $78,371 $74,275 $12,437 $9,377 $101,518

The following assumptions were made when estimating incidental recreation benefits.

There are large, similar areas adjacent to the ARTM study area to which recreational

users might shift if freshwater flows negatively impacted recreational fishing. These are

the Atchafalaya Basin to the west of the study area, the Lake Verret area to the north of

the study area and the Barataria Basin to the east of the study area. These areas are

similar to the ARTM area, and also are impacted by either erosion or siltation.

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There is the possibility of recreational users shifting into the study area from outside as

the ecosystem improves, especially if adjacent areas deteriorate. Each adjacent area has

ecosystem restoration efforts planned, and depending upon the schedule and success of

these projects, recreational users may shift to the ARTM study area. However, it is

assumed that there will not be a shift of recreational users from these adjacent areas into

the Atchafalaya Basin.

The consensus of the ARTM Focus Group was that the study area was large enough to

allow recreational users to shift locations within the study area, to adjust to the near term

impacts of alternatives instead of leaving the study area. Thus it is assumed that there is

no shifting away from the study area and into adjacent areas.

The study area attracts participants from outside the region who may purchase either

resident or nonresident licenses within the project area. For this reason, when estimating

the number of participants, it is assumed that the higher of the two numbers is more

accurate. This figure may still understate the number of recreational fishermen and

hunters as state residents may purchase licenses in their home parishes and travel to the

study area.

Recreational user days are allocated equally between weekdays and weekends in the

ARTM study area because of local socioeconomic conditions. Many recreational users

are employed in the offshore petroleum industry which allows many weekdays off.

It is assumed that the annual number of user days in the study area does not vary during

the 50-year planning period. If the population of the study area were increasing at the

national rate, recreational use could be expected to increase during this time period.

However, the population of the study area has increased very slowly during the past thirty

years. Also, the primary recreational activities, fishing and hunting, have been in relative

decline nationally.

The ARTM area consists of three sub-regions, for which the impacts of alternatives might

differ. These are the western region, which is most impacted by diversions through

Avoca Lake, the central region, which is most impacted by diversions through the Houma

Navigation Canal, and the eastern region, which is most impacted by diversions through

Grand Bayou and canals connected to it. Most of the population in the study area is in the

central region, near the City of Houma, but recreational activity is disbursed widely

throughout the study area. Separate criteria points were not assigned to the regions, and it

is assumed that all sub-regions are impacted similarly.

The recreation benefits model is based upon estimates of salinity impacts at Years 5, 10,

20, and 50. Therefore, salinity levels for the years between these given points are

assumed to change linearly. Year 2 data was input for Model Year 5, Year 25 data was

input for Model Year 20, and Year 65 data was input for Model Year 50. A median value

between Year 2 data and Year 25 data was used for Model Year 10.

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Houma Navigation Lock  Appendix Q  Incidental Recreation Benefits

Q-10

The increase in Average Annual Habitat Units (AAHUs) for each alternative was also

provided. Two types of AAHUs were estimated for each alternative, emergent marsh

AAHUs and open water AAHUs. Only the aggregate of both types of AAHUs was

provided. The two types of AAHUs could have different impacts on recreation.

However, the Habitat Analysis Report was not provided, and no attempt was made to

estimate recreation benefits based upon the two types of AAHUs.

The net change in AAHUs was assumed to increase linearly for the first 20 years and

then stop. Therefore, at Project Year 5, the assumption was made that one fourth of

expected additional AAHUs would be created, at Project Year 10 one half would be

created, all AAHUs would be created by Project Year 20 and those AAHUs would

remain constant through Project Year 50.

The western portion of the study area is a prime duck hunting/waterfowl nesting area.

The general unit day values for recreation may understate the NED benefits of duck

hunting. This sport requires specialized skill, and advanced planning. The value for duck

hunting leases, the cost of membership in duck hunting clubs, and the time spent building

duck hunting blinds all indicate that the unit day value of duck hunting is higher than

$9.72 per day, as estimated using general unit day values.

In the without project condition, there are many smaller environmental restoration

efforts planned under CWPPRA. For this analysis, the assumption is made that these

smaller projects will not improve habitat or recreation from base year conditions.

However, these smaller projects are considered sufficient to prevent further coastal

erosion and habitat deterioration in the study area.

Q5.1 References

2006 National Survey of Fishing, Hunting, and Wildlife Related Recreation, U.S. Fish

and Wildlife Service Louisiana, issued March 2008

Louisiana Statewide Comprehensive Outdoor Recreation Plan 2003-2008, Louisiana

Department of Recreation and Tourism, December 2004

Louisiana Statewide Comprehensive Outdoor Recreation Plan 2009-2013, Louisiana

Department of Recreation and Tourism, July 2009

Net Economic Values of Wildlife Related Recreation in 2006, U.S. Fish and Wildlife

Service, Report 2006-05, July 2009

USACE, Economic Guidance Memorandum 10-03: Unit Day Values for Recreation,

Fiscal Year 2010, November 2009

USACE, ER 1105-2-100, Chapter 3: Corps Civil Works Missions, April 2000

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