U.S. GOVERNMENT PRINTING OFFICE

68–496 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 II OF VI 

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

Infrastructure and ordered to be printed 

2:44 Sep 29 2011 Jkt 068496 PO 00000 Frm 00003 Fmt 4012 Sfmt 4012 E:\HR\OC\HD043V2 XXX HD043V2

LOUISIANA COASTAL AREA (LCA)

ECOSYSTEM RESTORATION STUDY

Volume II of VI

Final Integrated Feasibility Study and

Supplemental Environmental Impact Statement

for the

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

October 2010

U.S Army Corps of Engineers

New Orleans District

Coastal Protection and

Restoration Authority

(1)
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LOUISIANA COASTAL AREA (LCA)

ECOSYSTEM RESTORATION STUDY

Volume II of VI

Final Integrated Feasibility Study and

Supplemental Environmental Impact Statement

for the

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, 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.

October 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 II which is the element-specific analysis for the

The Louisiana Coastal Area-Amite River Diversion Canal Modification Element.

Volume I: Summary

Volume II: Amite River Diversion Canal Modification

Volume III: Atchafalaya Conveyance to N. Terrebonne Marshes

Volume IV: Convent/Blind River Diversion

Volume V: Terrebonne Basin Barrier Shoreline Restoration

Volume VI: White Ditch Diversion

If you have any questions, or require additional information, please contact:

Mr. Timothy Axtman, Senior Plan Formulator

U.S. Army Corps of Engineers New Orleans District;

P. O. Box 60267, New Orleans, LA 70160-0267

(504) 862-1921, email: Timothy.J.Axtman@usace.army.mil

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6
Final Integrated Feasibility Study and Supplemental

Environmental Impact Statement

for the

LCA Amite River Diversion Canal (ARDC) Modification

Project

LEAD AGENCY: U.S. Army Corps of Engineers (USACE) – Mississippi Valley

Division, New Orleans District

ABSTRACT: The USACE proposes to dredge openings in the existing ARDC

dredged material berm, construct bifurcated conveyance channels, and establish

vegetative plantings in the study area. The natural hydrology in the study area has

been modified by the ARDC and a railroad grade. Sea level changes and geological

subsidence have compounded these effects, leading to poor swamp health and

ecosystem degradation. This project would establish hydrologic connectivity

between the ARDC and the western Maurepas Swamp, allowing the swamp to drain

during seasonal low-flow conditions in the Amite River and promoting the

germination and survival of the seedlings of bald cypress and other trees. This

connectivity would allow nutrients and sediments to be introduced into the swamp

during flood events and localized rainfall events and improve biological productivity.

Without action, the swamp habitat surrounding the ARDC would continue the

conversion from a freshwater swamp to freshwater marsh and open water. Direct

impacts would be the continued impoundment of swamp water within the study

area, decreased hydrologic connectivity, and a transition toward marsh and salinity

tolerant vegetation. Indirect effects would be the decline of wildlife, fishery, and

vegetative resources. Flora and fauna may change as salt-tolerant species replace

fresh water species. Existing habitat would convert to waterbottoms and alter the

benthic community, decreasing available nutrients and detritus. Cumulative

impacts would be the projected conversion of 18,204 acres of swamp to fresh marsh

and open water. The water and air treatment functions of wetlands would subside,

and the integrity of existing resources within the study area would be endangered.

Excluding the No-Action Alternative, the final array of alternatives included seven

options. Alternative 33 was chosen as the recommended plan. It would restore

1,602 acres of swamp habitat, create 679 Average Annual Habitat Units (AAHUs),

5.0 acres of bottomland hardwood habitat, establish hydrologic connectivity, promote

the germination and survival of the seedlings of bald cypress and other trees, and

improve biological productivity. According to the Micro-Computer Aided Cost

Estimating System (MCACES), the total fully funded estimated cost for construction

of this alternative would be $8,540,000.

COMMENTS: Please send comments or questions on this SEIS to the U.S. Army

Corps of Engineers, New Orleans District, Attention: William P. Klein, Jr., P.O. Box

60267, New Orleans, Louisiana 70160-0267. Telephone: (504) 862-2540; FAX: (504)

862-2088. The official closing date for receipt of comments will be 30 days from the

date on which the Notice of Availability of the Final SEIS appeared in the Federal

Register.

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Table of Contents Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) TOC-i October 2010

TABLE OF CONTENTS

Volume II – [Louisiana Coastal Area-Amite River Diversion Canal Modification]

Integrated Feasibility Report and Supplemental

Environmental Impact Statement 1

Section Page

Executive Summary......................................................................................... ES-i

TABLE OF CONTENTS ................................................................................ TOC-i

FIGURES .............................................................................................. TOC-xv

TABLES ............................................................................................. TOC-xix

APPENDICES (VOLUME II)......................................................................TOC-xxiii

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

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

1.2 PURPOSE AND SCOPE* .................................................................1-3

1.3 STUDY AREA* .................................................................................1-5

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

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

1.5.1 Federal..............................................................................1-10

1.5.2 State..................................................................................1-14

1.6 PLANNING PROCESS AND REPORT ORGANIZATION ...........1-14

1.7 USACE CAMPAIGN PLAN............................................................1-15

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

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

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

2.3 PROBLEMS, NEEDS, AND OPPORTUNITIES* ...........................2-3

2.3.1 2004 LCA Ecosystem Restoration Report.........................2-3

2.3.2 Conceptual Ecological Model.............................................2-5

2.3.3 Problems.............................................................................2-7

2.3.3.1 Modification of Natural Hydrology........................2-8

2.3.3.2 Subsidence ..............................................................2-8

2.3.3.3 Sea Level Rise.........................................................2-9

2.3.3.4 Tropical Cyclone Events.........................................2-9

2.3.4 Effects...............................................................................2-10

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

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Environmental Impact Statement1

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2.3.4.1 Impoundment .......................................................2-11

2.3.4.2 Decreased Connectivity Resulting in Decreased

Freshwater, Sediment, and Nutrient

Inputs into the Swamps.....................................2-14

2.3.4.3 Habitat Changes and Land Loss .........................2-15

2.3.4.4 Increased Invasive Species...................................2-18

2.3.5 Needs ................................................................................2-18

2.3.5.1 Future Without Project Condition.......................2-20

2.3.6 Opportunities ..................................................................2-22

2.4 PLANNING OBJECTIVES.............................................................2-23

2.4.1 Goals.................................................................................2-23

2.4.2 Objectives .........................................................................2-24

2.5 PLANNING CONSTRAINTS .........................................................2-25

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

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

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

3.1.2 Plan Criteria.......................................................................3-2

3.1.2.1 Completeness ..........................................................3-2

3.1.2.2 Effectiveness ...........................................................3-2

3.1.2.3 Efficiency.................................................................3-2

3.1.2.4 Acceptability ...........................................................3-2

3.1.3 Environmental Operating Principles................................3-2

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

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

3.2.2 Description of Management Measures..............................3-4

3.2.3 Screening/Evaluation of Management Measures.............3-7

3.2.4 Management Measures Not Carried

Forward for Further Analysis ......................................3-12

3.3 PRELIMINARY ALTERNATIVES PLANS ...................................3-26

3.3.1 Development of Alternative Plans ..................................3-35

3.3.1.1 Vegetative Plantings ............................................3-36

3.3.2 Description of Alternative Plans .....................................3-38

3.3.3 Screening/Evaluation of Alternative Plans.....................3-38

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Environmental Impact Statement1

Section Page

3.3.4 Alternative Plans Not Carried Forward for

Further Analysis .........................................................3-40

3.4 FINAL ARRAY OF ALTERNATIVES (ALTERNATIVES

STUDIED IN DETAIL)...................................................................3-40

3.4.1 No-Action Alternative (Future Without

Project Condition) .......................................................3-40

3.4.2 Alternative 33 (NE-1/NE-2).............................................3-41

3.4.3 Alternative 34 (SE-1/SE-2) ..............................................3-47

3.4.4 Alternative 35 (SE-1) .......................................................3-50

3.4.5 Alternative 36 (NE-1/NE-2, SE-1/SE-2)..........................3-52

3.4.6 Alternative 37 (SE-1/SE-2, SE-1) ....................................3-54

3.4.7 Alternative 38 (NE-1/NE2, SE-1) ....................................3-56

3.4.8 Alternative 39 (NE-1/NE-2, SE-1/SE-2 –

All Subunits Combined)...............................................3-56

3.5 COMPARISON OF ALTERNATIVE PLANS ................................3-60

3.5.1 Cost Estimates for the Final Array.................................3-60

3.5.2 Wetland Value Assessment Model ..................................3-62

3.5.3 Institute of Water Resources Planning Suite

Analysis ........................................................................3-72

3.5.4 Summary Comparison of Final Array

of Alternatives...............................................................3-75

3.6 NATIONAL ECOSYSTEM RESTORATION PLAN......................3-76

3.7 PLAN SELECTION - RECOMMENDED PLAN ...........................3-76

3.7.1 Components......................................................................3-77

3.7.2 Design, Environmental, and Construction

Considerations.............................................................3-93

3.7.3 Real Estate Requirements...............................................3-94

3.7.4 OMRR&R Considerations................................................3-95

3.7.5 Monitoring Plan and Adaptive Management .................3-95

3.7.5.1 Description of Monitoring Activity and

Adaptive Management....................................3-95

3.7.5.2 Performance Measures for Monitoring................3-97

3.7.5.3 Cost and Duration of Monitoring and

Adaptive Management ..................................3-100

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Environmental Impact Statement1

Section Page

3.7.6 Effectiveness of Recommended Plan in

Meeting Goals and Objectives ..................................3-100

3.7.7 Effectiveness of Recommended Plan in

Meeting Environmental Operating Principals ........3-102

3.7.8 Compensatory Mitigation Measures .............................3-102

3.7.9 Micro-Computer Aided Cost Estimating System..........3-102

3.7.10 Construction Considerations ........................................3-102

3.7.11 Significance ...................................................................3-104

3.7.11.1 Rationale for the Recommended Plan................3-104

3.7.11.2 Significance of Recommended Plan....................3-108

3.7.11.3 Acceptability .......................................................3-108

3.7.11.4 Completeness ......................................................3-109

3.7.11.5 Efficiency.............................................................3-109

3.7.11.6 Effectiveness .......................................................3-109

3.7.12 Sustainability................................................................3-109

3.8 RISK AND UNCERTAINTY.........................................................3-112

3.9 IMPLEMENTATION REQUIREMENTS.....................................3-117

3.9.1 Schedule .........................................................................3-117

3.9.2 Implementation Responsibilities...................................3-118

3.9.3 Cost Sharing...................................................................3-121

3.9.4 Environmental Commitments.......................................3-123

3.9.5 Financial Requirements ................................................3-123

3.9.6 Views of Non-Federal Sponsor ......................................3-124

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

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

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

4.1.2 Climate ...............................................................................4-1

4.1.3 Geomorphic and Physiographic Setting............................4-2

4.2 SIGNIFICANT RESOURCES ..........................................................4-3

4.2.1 Soils and Waterbottoms.....................................................4-3

4.2.1.1 Soils.........................................................................4-4

4.2.1.2 Waterbottoms .........................................................4-8

4.2.2 Hydrology ...........................................................................4-8

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Environmental Impact Statement1

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4.2.2.1 Flow and Water Levels...........................................4-9

4.2.2.2 Sedimentation and Erosion..................................4-13

4.2.2.3 Water Use and Supply .........................................4-15

4.2.2.4 Groundwater.........................................................4-15

4.2.3 Water Quality and Salinity .............................................4-16

4.2.3.1 Water Quality .......................................................4-17

4.2.3.2 Salinity Regimes...................................................4-18

4.2.4 Air Quality........................................................................4-21

4.2.5 Noise .................................................................................4-22

4.2.6 Vegetation Resources.......................................................4-22

4.2.6.1 Riparian Vegetation .............................................4-25

4.2.6.2 Wetland Vegetation..............................................4-25

4.2.6.3 Upland Vegetation................................................4-31

4.2.6.4 Submerged Aquatic Vegetation ...........................4-32

4.2.6.5 Invasive Species – Vegetation..............................4-33

4.2.6.6 Rare, Unique, and Imperiled Vegetative

Communities.....................................................4-33

4.2.7 Wildlife and Habitat ........................................................4-34

4.2.8 Aquatic Resources............................................................4-38

4.2.8.1 Plankton................................................................4-38

4.2.8.2 Benthic ..................................................................4-40

4.2.9 Fishery Resources ............................................................4-40

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

4.2.11 Threatened and Endangered Species.............................4-43

4.2.12 Cultural and Historic Resources ....................................4-48

4.2.13 Aesthetics ........................................................................4-51

4.2.14 Recreation........................................................................4-53

4.2.15 Socioeconomics and Human Resources..........................4-54

4.2.15.1 Population and Housing .......................................4-54

4.2.15.2 Employment and Income......................................4-56

4.2.15.3 Community Cohesion ...........................................4-57

4.2.15.4 Environmental Justice .........................................4-57

4.2.15.5 Infrastructure .......................................................4-60

4.2.15.6 Business and Industry..........................................4-60

4.2.15.7 Traffic and Transportation...................................4-62

4.2.15.8 Public Facilities and Services...............................4-63

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Environmental Impact Statement1

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4.2.15.9 Local Government Finance ..................................4-63

4.2.15.10 Tax Revenue and Property Values.......................4-64

4.2.15.11 Community and Regional Growth .......................4-64

4.2.15.12 Land Use Socioeconomics.....................................4-64

4.2.15.13 Navigation.............................................................4-65

4.2.15.14 Man-Made Resources ...........................................4-67

4.2.15.15 Natural Resources ................................................4-67

4.2.16 Hazardous, Toxic, and Radioactive Wastes ...................4-69

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

5.1 SOILS AND WATERBOTTOMS ......................................................5-2

5.1.1 Soils ....................................................................................5-2

5.1.1.1 No-Action Alternative ............................................5-2

5.1.1.2 Alternative 33 (Recommended Plan) .....................5-2

5.1.1.3 Alternative 34 .......................................................5-15

5.1.1.4 Alternative 35 .......................................................5-15

5.1.1.5 Alternative 36 .......................................................5-15

5.1.1.6 Alternative 37 .......................................................5-15

5.1.1.7 Alternative 38 .......................................................5-16

5.1.1.8 Alternative 39 .......................................................5-16

5.1.2 Waterbottoms...................................................................5-16

5.1.2.1 No-Action Alternative ..........................................5-16

5.1.2.2 Alternative 33 (Recommended Plan) ...................5-17

5.1.2.3 Alternative 34 .......................................................5-17

5.1.2.4 Alternative 35 .......................................................5-17

5.1.2.5 Alternative 36 .......................................................5-18

5.1.2.6 Alternative 37 .......................................................5-18

5.1.2.7 Alternative 38 .......................................................5-18

5.1.2.8 Alternative 39 .......................................................5-18

5.2 HYDROLOGY..................................................................................5-19

5.2.1 Flow and Water Levels ....................................................5-28

5.2.1.1 No-Action Alternative ..........................................5-28

5.2.1.2 Alternative 33 (Recommended Plan) ...................5-29

5.2.1.3 Alternative 34 .......................................................5-29

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Environmental Impact Statement1

Section Page

5.2.1.4 Alternative 35 .......................................................5-29

5.2.1.5 Alternative 36 .......................................................5-30

5.2.1.6 Alternative 37 .......................................................5-30

5.2.1.7 Alternative 38 .......................................................5-30

5.2.1.8 Alternative 39 .......................................................5-30

5.2.2 Sedimentation and Erosion .............................................5-31

5.2.2.1 No-Action Alternative ..........................................5-31

5.2.2.2 Alternative 33 (Recommended Plan) ...................5-31

5.2.2.3 Alternative 34 .......................................................5-32

5.2.2.4 Alternative 35 .......................................................5-32

5.2.2.5 Alternative 36 .......................................................5-32

5.2.2.6 Alternative 37 .......................................................5-32

5.2.2.7 Alternative 38 .......................................................5-33

5.2.2.8 Alternative 39 .......................................................5-33

5.2.3 Water Use and Supply .....................................................5-33

5.2.3.1 No-Action Alternative ..........................................5-33

5.2.3.2 Alternative 33 (Recommended Plan) ...................5-34

5.2.3.3 Alternatives 34-39 ................................................5-34

5.2.4 Groundwater ....................................................................5-34

5.2.4.1 No-Action Alternative ..........................................5-34

5.2.4.2 Alternative 33 (Recommended Plan) ...................5-34

5.2.4.3 Alternatives 34-39................................................5-35

5.3 WATER QUALITY AND SALINITY..............................................5-35

5.3.1 Water Quality...................................................................5-35

5.3.1.1 No-Action Alternative...........................................5-35

5.3.1.2 Alternative 33 (Recommended Plan) ...................5-36

5.3.1.3 Alternatives 34-39 ................................................5-37

5.3.2 Salinity .............................................................................5-37

5.3.2.1 No-Action Alternative...........................................5-37

5.3.2.2 Alternative 33 (Recommended Plan) ...................5-38

5.3.2.3 Alternative 34 .......................................................5-38

5.3.2.4 Alternative 35 .......................................................5-38

5.3.2.5 Alternative 36 .......................................................5-39

5.3.2.6 Alternative 37 .......................................................5-39

5.3.2.7 Alternative 38 .......................................................5-39

5.3.2.8 Alternative 39 .......................................................5-40

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Environmental Impact Statement1

Section Page

5.4 AIR QUALITY.................................................................................5-40

5.4.1 The No-Action Alternative...............................................5-40

5.4.2 Alternative 33 (Recommended Plan)...............................5-40

5.4.3 Alternatives 34-39............................................................5-41

5.5 NOISE..............................................................................................5-41

5.5.1 The No-Action Alternative...............................................5-41

5.5.2 Alternative 33 (Recommended Plan)...............................5-41

5.5.3 Alternatives 34-39............................................................5-44

5.6 VEGETATION RESOURCES.........................................................5-44

5.6.1 Riparian Vegetation Resources ......................................5-44

5.6.1.1 No-Action Alternative ..........................................5-44

5.6.1.2 Alternative 33 (Recommended Plan) ...................5-44

5.6.1.3 Alternative 34 .......................................................5-45

5.6.1.4 Alternative 35 .......................................................5-45

5.6.1.5 Alternative 36 .......................................................5-46

5.6.1.6 Alternative 37 .......................................................5-46

5.6.1.7 Alternative 38 .......................................................5-46

5.6.1.8 Alternative 39 .......................................................5-47

5.6.2 Wetland Vegetation Resources.......................................5-47

5.6.2.1 No-Action Alternative ..........................................5-48

5.6.2.2 Alternative 33 (Recommended Plan) ...................5-48

5.6.2.3 Alternative 34 .......................................................5-49

5.6.2.4 Alternative 35 .......................................................5-50

5.6.2.5 Alternative 36 .......................................................5-50

5.6.2.6 Alternative 37 .......................................................5-51

5.6.2.7 Alternative 38 .......................................................5-51

5.6.2.8 Alternative 39 .......................................................5-52

5.6.3 Upland Vegetation Resources.........................................5-53

5.6.3.1 No-Action Alternative ..........................................5-53

5.6.3.2 Alternative 33 (Recommended Plan) ...................5-53

5.6.3.3 Alternative 34 .......................................................5-53

5.6.3.4 Alternative 35 .......................................................5-54

5.6.3.5 Alternative 36 .......................................................5-54

5.6.3.6 Alternative 37 .......................................................5-54

5.6.3.7 Alternative 38 .......................................................5-55

5.6.3.8 Alternative 39 .......................................................5-55

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Environmental Impact Statement1

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5.6.4 Submerged Aquatic Vegetation (SAV) ...........................5-56

5.6.4.1 No-Action Alternative ..........................................5-56

5.6.4.2 Alternative 33 (Recommended Plan)...................5-56

5.6.4.3 Alternatives 34-39................................................5-56

5.6.5 Invasive Species Vegetation ...........................................5-56

5.6.5.1 No-Action Alternative ..........................................5-56

5.6.5.2 Alternative 33 (Recommended Plan)...................5-57

5.6.5.3 Alternatives 34-39 ................................................5-57

5.7 WILDLIFE HABITAT.....................................................................5-57

5.7.1 The No-Action Alternative..............................................5-57

5.7.2 Alternative 33 (Recommended Plan)..............................5-58

5.7.3 Alternative 34..................................................................5-59

5.7.4 Alternative 35..................................................................5-59

5.7.5 Alternative 36..................................................................5-59

5.7.6 Alternative 37..................................................................5-59

5.7.7 Alternative 38..................................................................5-60

5.7.8 Alternative 39..................................................................5-60

5.8 FISHERY RESOURCES.................................................................5-60

5.8.1 The No-Action Alternative..............................................5-60

5.8.1.1 No-Action Alternative ..........................................5-60

5.8.1.2 Alternative 33 (Recommended Plan) ...................5-61

5.8.1.3 Alternative 34 .......................................................5-62

5.8.1.4 Alternative 35 .......................................................5-62

5.8.1.5 Alternative 36 .......................................................5-63

5.8.1.6 Alternative 37 .......................................................5-63

5.8.1.7 Alternative 38 .......................................................5-63

5.8.1.8 Alternative 39 .......................................................5-63

5.8.2 Alternative 33 (Recommended Plan)..............................5-64

5.8.2.1 No-Action Alternative ..........................................5-64

5.8.2.2 Alternative 33 (Recommended Plan) ...................5-64

5.8.2.3 Alternatives 34-39 ................................................5-65

5.9 AQUATIC RESOURCES ................................................................5-65

5.9.1 Benthic Resources...........................................................5-65

5.9.2 Alternative 33 (Recommended Plan)..............................5-66

5.9.3 Alternative 334................................................................5-66

5.9.4 Alternative 35..................................................................5-67

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Environmental Impact Statement1

Section Page

5.9.5 Alternative 36..................................................................5-67

5.9.6 Alternative 37..................................................................5-67

5.9.7 Alternative 38..................................................................5-67

5.9.8 Alternative 39..................................................................5-68

5.10 ESSENTIAL FISH HABITAT (EFH).............................................5-68

5.10.1 The No-Action Alternative.............................................5-68

5.10.2 Alternatives 33 (Recommended Plan)...........................5-68

5.10.3 Alternative 34-39 ...........................................................5-68

5.11 THREATENED AND ENDANGERED SPECIES.........................5-68

5.11.1 The No-Action Alternative.............................................5-68

5.11.2 Alternative 33 (Recommended Plan).............................5-69

5.11.3 Alternatives 34-39..........................................................5-71

5.12 CULTURAL AND HISTORIC RESOURCES ................................5-71

5.12.1 No-Action Alternative ...................................................5-71

5.12.2 Alternative 33 (Recommended Plan).............................5-71

5.12.3 Alternatives 34-39..........................................................5-72

5.13 AESTHETICS..................................................................................5-72

5.13.1 The No-Action Alternative.............................................5-72

5.13.2 Alternative 33 (Recommended Plan).............................5-72

5.13.3 Alternatives 34-39..........................................................5-73

5.14 RECREATION.................................................................................5-73

5.14.1 No-Action Alternative....................................................5-73

5.14.2 Alternative 33 (Recommended Plan).............................5-73

5.14.3 Alternatives 34-39..........................................................5-74

5.15 SOCIOECONOMIC AND HUMAN RESOURCES........................5-74

5.15.1 Population and Housing ................................................5-74

5.15.1.1 No-Action Alternative...........................................5-74

5.15.1.2 Alternative 33 (Recommended Plan) ...................5-74

5.15.1.3 Alternatives 34-39 ................................................5-75

5.15.2 Employment and Income ...............................................5-75

5.15.2.1 No-Action Alternative...........................................5-75

5.15.2.2 Alternative 33 (Recommended Plan) ...................5-75

5.15.2.3 Alternatives 34-39 ................................................5-75

5.15.3 Community Cohesion.....................................................5-76

5.15.3.1 No-Action Alternative...........................................5-76

5.15.3.2 Alternative 33 (Recommended Plan) ...................5-76

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TABLE OF CONTENTS (cont’d)

Volume II – [Louisiana Coastal Area-Amite River Diversion Canal Modification]

Integrated Feasibility Report and Supplemental

Environmental Impact Statement1

Section Page

5.15.3.3 Alternatives 34-39 ................................................5-76

5.15.4 Environmental Justice...................................................5-76

5.15.4.1 No-Action Alternative...........................................5-76

5.15.4.2 Alternative 33 (Recommended Plan) ...................5-77

5.15.4.3 Alternatives 34-39 ................................................5-77

5.15.5 Infrastructure................................................................5-77

5.15.5.1 No-Action Alternative...........................................5-77

5.15.5.2 Alternative 33 (Recommended Plan) ...................5-78

5.15.5.3 Alternatives 34-39 ................................................5-78

5.15.6 Business and Industry..................................................5-78

5.15.6.1 No-Action Alternative...........................................5-78

5.15.6.2 Alternative 33 (Recommended Plan) ...................5-78

5.15.6.3 Alternatives 34-39 ................................................5-79

5.15.7 Traffic and Transportation ...........................................5-79

5.15.7.1 No-Action Alternative...........................................5-79

5.15.7.2 Alternative 33 (Recommended Plan) ...................5-79

5.15.7.3 Alternatives 34-39 ................................................5-80

5.15.8 Public Facilities and Services.......................................5-80

5.15.8.1 No-Action Alternative...........................................5-80

5.15.8.2 Alternative 33 (Recommended Plan) ...................5-80

5.15.8.3 Alternatives 34-39 ................................................5-80

5.15.9 Local Government Finance...........................................5-81

5.15.9.1 No-Action Alternative...........................................5-81

5.15.9.2 Alternative 33 (Recommended Plan) ...................5-81

5.15.9.3 Alternatives 34-39 ................................................5-81

5.15.10 Tax Revenue and Property Values...............................5-81

5.15.10.1 No-Action Alternative...........................................5-81

5.15.10.2 Alternative 33 (Recommended Plan) ...................5-82

5.15.10.3 Alternatives 34-39 ................................................5-82

5.15.11 Community and Regional Growth................................5-82

5.15.11.1 No-Action Alternative...........................................5-82

5.15.11.2 Alternative 33 (Recommended Plan) ...................5-83

5.15.11.3 Alternatives 34-39 ................................................5-83

5.15.12 Land Use Socioeconomics .............................................5-83

5.15.12.1 Agriculture............................................................5-84

5.15.12.2 Forestry.................................................................5-84

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TABLE OF CONTENTS (cont’d)

Volume II – [Louisiana Coastal Area-Amite River Diversion Canal Modification]

Integrated Feasibility Report and Supplemental

Environmental Impact Statement1

Section Page

5.15.12.3 Public Lands .........................................................5-85

5.15.13 Navigation.....................................................................5-86

5.15.13.1 No-Action Alternative .........................................5-86

5.15.13.2 Alternative 33 (Recommended Plan)..................5-87

5.15.13.3 Alternatives 34-39 ...............................................5-87

5.15.14 Man-Made Resources....................................................5-87

5.15.14.1 Oil, Gas, Utilities and Pipelines...........................5-87

5.15.14.2 Flood Control and Hurricane Protection .............5-88

5.15.15 Natural Resources.........................................................5-90

5.15.15.1 Commercial Fisheries...........................................5-90

5.16 HAZARDOUS, TOXIC, AND RADIOACTIVE WASTE.................5-92

5.16.1 No-Action Alternative...................................................5-92

5.16.2 Alternative 33 (Recommended Plan).............................5-92

5.16.3 Alternatives 34-39..........................................................5-92

5.17 UNAVOIDABLE ADVERSE IMPACTS.........................................5-93

5.18 RELATIONSHIIP OF SHORT-TERM USES AND

LONG-TERM PRODUCTIVITY................................................5-93

5.19 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT

OF RESOURCES.......................................................................5-93

5.20 MITIGATION ..................................................................................5-93

5.21 ENVIRONMENTAL CONSEQUENCES SUMMARY ..................5-94

6.0 PUBLIC INVOLVEMENT* .....................................................................6-1

6.1 NEPA SCOPING ...............................................................................6-1

6.2 OTHER PUBLIC COMMENTS, AREAS OF CONTROVERSY,

UNRESOLVED ISSUES .............................................................6-4

6.2.1 Land Owner Involvement..................................................6-5

6.2.2 Non-Governmental Organization (NGO)

Involvement............................................................................6-5

6.2.3 Parish Involvement............................................................6-5

6.3 PUBLIC COMMENTS ON THE DSEIS ..........................................6-5

7.0 COORDINATION AND COMPLIANCE*...............................................7-1

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TABLE OF CONTENTS (cont’d)

Volume II – [Louisiana Coastal Area-Amite River Diversion Canal Modification]

Integrated Feasibility Report and Supplemental

Environmental Impact Statement1

Section Page

7.1 U.S. ARMY CORPS OF ENGINEERS (USACE)

PRINCIPLES AND GUIDELINES (P&G)..................................7-1

7.2 ENVIRONMENTAL COORDINATION AND COMPLIANCE.......7-1

7.2.1 Clean Water Act – Section 404(b)(1) .................................7-3

7.2.2 Section 122 of the Rivers and Harbors Act .......................7-3

7.2.3 Coastal Zone Management Act of 1972.............................7-3

7.2.4 Endangered Species Act of 1973........................................7-4

7.2.5 Magnuson-Stevens Fishery Conservation and

Management Act of 1996; and the MagnusonStevens Act Reauthorization of 2006 Essential

Fish Habitat (EFH)........................................................7-4

7.2.6 Clean Air Act – Air Quality Determination......................7-4

7.2.7 National Historic Preservation Act of 1966 ......................7-5

7.2.8 Farmland Protection Policy Act (Prime and Unique

Farmlands) ....................................................................7-5

7.2.9 Executive Order 13186 – Migratory Bird Habitat

Protection......................................................................7-5

7.2.10 Executive Order 12898 – Environmental Justice...........7-6

7.2.11 Executive Order 13112 – Invasive Species .....................7-7

7.2.12 Executive Order 11990 – Protection of Wetlands...........7-7

7.2.13 Executive Order 11988 – Floodplain Management ........7-8

7.2.14 Uniform Relocation Assistance and Real Property

Acquisition Policies Act of 1970

(Public Law 91-646)......................................................7-8

7.2.15 Louisiana State Rare, Threatened, and Endangered

Species, and Natural Communities Coordination ......7-9

7.2.16 Clean Water Act – Section 401 Water Quality ...............7-9

7.2.17 U.S. Fish and Wildlife Coordination Act

Report...........................................................................7-9

8.0 CONCLUSIONS AND DETERMINATIONS* ......................................8-1

8.1 AREAS OF CONTROVERSY AND UNRESOLVED ISSUES ........8-1

8.2 CONCLUSIONS................................................................................8-1

8.3 RECOMMENDATIONS....................................................................8-2

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TABLE OF CONTENTS (cont’d)

Volume II – [Louisiana Coastal Area-Amite River Diversion Canal Modification]

Integrated Feasibility Report and Supplemental

Environmental Impact Statement1

Section Page

9.0 DISTRIBUTION LIST AND OTHER* ...................................................9-1

9.1 DISTRIBUTION LIST ......................................................................9-1

9.2 LIST OF PREPARERS......................................................................9-1

9.3 LITERATURE CITED ......................................................................9-3

9.4 GLOSSARY......................................................................................9-16

9.5 ACRONYMS, ABBREVIATIONS, SYMBOLS, AND

INITIALISMS ............................................................................9-27

ATTACHMENTS

Attachment 1: Non-Federal Sponsor's Letter of Intent

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WRDA 2007 Section 7006(e)(3) TOC-xv October 2010

LIST OF FIGURES

Figure Page

1.1 Related Projects in Vicinity of Amite River Diversion Canal

Modification.......................................................................................1-4

1.2 Study Area Region .......................................................................................1-6

1.3 Study Area and Subunits ............................................................................1-7

2.1 Conceptual Ecological Model, Amite River Diversion Canal

Modification Project ..........................................................................2-6

2.2 Habitat Types.............................................................................................2-12

2.3 Predicated Land Change for Coastal Louisiana.......................................2-17

3.1 1940 Aerial Photography with Area of Impact Outlined .........................3-11

3.2 1940 Aerial Photography—Close-Up of Area of Interest .........................3-11

3.3 2005 Color Infrared Photography—Area of Interest................................3-12

3.4 Alternative 33.............................................................................................3-42

3.5 Typical 70 ft. Cross Section through ARDC Dredged Material Berm .....3-43

3.6 Typical 70 ft. Cross Section through ARDC Native Swamp ....................3-44

3.7 Typical 50 ft. Cross Section through ARDC Native Swamp ....................3-45

3.8 Typical 30 ft. Cross Section through ARDC Native Swamp ....................3-46

3.9 Typical Conveyance Channel.....................................................................3-48

3.10 Alternative 34.............................................................................................3-49

3.11 Alternative 35.............................................................................................3-51

3.12 Alternative 36.............................................................................................3-53

3.13 Alternative 37.............................................................................................3-55

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LIST OF FIGURES (cont’d)

Figure Page

3.14 Alternative 38.............................................................................................3-57

3.15 Alternative 39.............................................................................................3-58

3.16 Project Benefits ..........................................................................................3-65

3.17 Comparison of Benefits for Final Array, Alternative 33 ..........................3-68

3.18 Comparison of Benefits for Final Array, Alternative 34 ..........................3-68

3.19 Comparison of Benefits for Final Array, Alternative 35 ..........................3-68

3.20 Comparison of Benefits for Final Array, Alternative 36 ..........................3-69

3.21 Comparison of Benefits for Final Array, Alternative 37 ..........................3-69

3.22 Comparison of Benefits for Final Array, Alternative 38 ..........................3-69

3.23 Comparison of Benefits for Final Array, Alternative 39 ..........................3-70

3.24 Net Benefits Gained by Final Array .........................................................3-70

3.25 IWR Cost versus Output............................................................................3-74

3.26 IWR Best Buy Comparison........................................................................3-75

3.27 Alternative 33 and Alternative 39 Comparison........................................3-89

3.28 Comparison of Habitat Units Over the Period Analysis ........................3-110

3.29 Net Benefits Obtained Over Period of Analysis .....................................3-111

4.1 Land Use/Land Cover Map..........................................................................4-5

4.2 Soils Map......................................................................................................4-6

4.3 Plot of Historic Rate from Daily Stage Data.............................................4-10

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LIST OF FIGURES (cont’d)

Figure Page

4.4 Hydrograph of Water Levels Obtained from Louisiana Department

of Natural Resources (LDNR) Gauges in the LCA ARDC

Study Area.......................................................................................4-12

4.5 Water Surface Elevations at the North Swamp at the Railroad

Grade and North Swamp at the Bridge in North American

Vertical Datum (NAVD) 88 (2006.81) and Three U.S.

Geological Survey (USGS) Gauges .................................................4-13

4.6 Mean Monthly Salinities from Four CRMS Stations in the Area............4-20

4.7 Land Cover within the LCA ARDC Study Area (USGS, 2009)................4-27

4.8 Wetland Type Map.....................................................................................4-29

4.9 Existing and Proposed Development Near the

LCA ARDC Study Area...................................................................4-55

4.10 Highways Near the LCA ARDC Study Area ............................................4-61

4.11 Public Lands Near the LCA ARDC Study Area .......................................4-66

4.12 Oil, Gas, and Utilities Near the LCA ARDC Study Area.........................4-68

5.1 Related Projects in Vicinity of Amite River Diversion Canal

Modification.....................................................................................5-13

5.2 Plot of Sea Level Rise for Each Case.........................................................5-21

5.3 Combined Effects of Low RSLR Estimate and Accretion.........................5-26

5.4 Combined Effects of Intermediate RSLR Estimate and Accretion ..........5-26

5.5 Combined Effects of High RSLR Estimate and Accretion .......................5-27

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Table of Contents Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) TOC-xix October 2010

LIST OF TABLES

Table Page

1.1 Hydrologic Subunits.....................................................................................1-9

1.2 Relevance of Prior Studies, Reports, Programs, and Water Projects

to the LCA ARDC Integrated Feasibility Report and EA .............1-10

2.1 Problems and Opportunities by LCA ARDC Study Area Subunits...........2-4

2.2 Conversion of Habitat Types (Years to Marsh) Alternative.....................2-11

3.1 Evaluation of Hydrologic Subunits .............................................................3-8

3.2 Management Measures Considered with Screening Results...................3-13

3.3 Description and Screening Results of Alternatives, Including

the Final Array................................................................................3-26

3.4 Matrix of Management Measures Used to Formulate

the Alternatives...............................................................................3-39

3.5 Alternative Quantities...............................................................................3-47

3.6 Comparison of Final Array of Alternatives...............................................3-60

3.7 Summary of Costs Estimates for the Final Array ....................................3-61

3.8 Summary of WVA Benefits of Final Array ...............................................3-65

3.9 Computed Exchange Channel Flows with RSLR .....................................3-66

3.10 Final Array Benefits ..................................................................................3-67

3.11 Ranking of Final Array..............................................................................3-71

3.12 Alternatives Costs and Benefits................................................................3-73

3.13 IWR-PLAN Results....................................................................................3-74

3.14 Conversion of Habitat Types (Years to Marsh) for each

Alternative.......................................................................................3-76

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LIST OF TABLES (cont’d)

Table Page

3.15 Summary Comparison of Final Array of Alternatives .............................3-79

3.16 Comparison of the NER and Recommended Plan ....................................3-91

3.17 Maximum Cost Including Inflation through Construction ......................3-91

3.18 Recommended Plan (Alternative 33) Construction Schedule ................3-105

3.19 Comparison of Habitat Units Obtained from the Recommended

Plan Over Period of Analysis........................................................3-111

3.20 Effect of Relative Sea Level Rise on Alternatives ..................................3-115

3.21 Years to Permanent Inundation..............................................................3-115

3.22 LCA ARDC SEIS Milestone Schedule.....................................................3-117

3.23 LCA ARDC Modification Project Implementation Schedule..................3-117

3.24 Cost Apportionment for the Recommended Plan....................................3-122

4.1 LDEQ Salinity in ppt.................................................................................4-19

4.2 CRMS Salinity Data Summary in ppt ......................................................4-20

4.3 Land Cover in the LCA ARDC Study Area by Acre

(2000 Louisiana Coastal Area Habitat Analysis) ..........................4-24

4.4 Common Plant Species in the Study Area by Habitat Type ....................4-30

4.5 Status, Functions of Interest, Trends, and Projections through 2050 for

Avifauna, Furbearers, Game Mammals, and Reptiles within

the LCA ARDC Study Area.............................................................4-36

4.6 Population Trends and Projections through 2050 for Fishery Species

within the Amite/Blind River Mapping Unit .................................4-42

4.7 Endangered (E) and Threatened (T) Plant and Animal Species

in Louisiana.....................................................................................4-45

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LIST OF TABLES (cont’d)

Table Page

4.8 Rare, Threatened, and Endangered Species and Natural

Communities Tracked by the LNHP, Ascension and

Livingston Parishes-January 2010.................................................4-46

4.9 Threatened and Endangered Plant and Animal Species in the

LCA ARDC Study Area...................................................................4-47

4.10 Identified Archaeological Sites Within the LCA ARDC

Study Area.......................................................................................4-50

4.11 Potential REC Sites Located Within or Near the LCA ARDC

Study Area.......................................................................................4-70

5.1 Comparison of Cumulative Impacts............................................................5-3

5.2 Net Acres Created, Restored, and/or Protected by Other Federal,

State, Local, and Private Restoration Efforts (LCA, 2004) ...........5-14

5.3 Summary of Five-year Sea Level Rise for Each Case ..............................5-20

5.4 Computed Exchange Channel Flows with RSLR .....................................5-22

5.5 Stage Duration with RSLR, Storage Area SE-1 .......................................5-23

5.6 Stage Duration with RSLR, Storage Area NE-2.......................................5-24

5.7 Years to Permanent Inundation................................................................5-25

5.8 Effect of RSLR on Alternatives .................................................................5-27

5.9 Air Quality Emission Analysis for Nitrous Oxide ....................................5-42

5.10 Air Quality Emission Analysis for Volatile Organic Compounds ............5-43

5.11 Degradation and Benefits for Final Array................................................5-48

6.1 Public Scoping Comment Themes by Percentages of Occurrence..............6-2

6.2 Public Scoping Comments Considered........................................................6-3

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LIST OF TABLES (cont’d)

Table Page

7.1 Relevant Federal Statutory Authorities and Executive Orders ................7-1

7.2 Relevant State Statutory Authorities .........................................................7-3

9.1 List of Preparers ..........................................................................................9-1

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APPENDICES (Volume II)

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 State Historic Preservation Officer Coordination Letter and

Programmatic Agreement

APPENDIX G Responses to Comments

APPENDIX H Value Engineering Report

APPENDIX I Adaptive Management/Monitoring Plan

APPENDIX J Real Estate Plan

APPENDIX K Economics and Benefits

APPENDIX L Engineering Appendix

APPENDIX M HTRW Report Summary

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Executive Summary Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) ES-i October 2010

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) program. This authorization was recommended by

the Chief of Engineer’s Report, dated January 31, 2005. This report recommended

projects and features that reintroduce historical flows of river water, nutrients, and

sediment to coastal wetlands; restore coastal hydrology to minimize saltwater

intrusion; and maintain the structural integrity of the coastal ecosystem. One

project feature of this recommendation was modifications to the Amite River

Diversion Canal (ARDC).

This report concerns the LCA ARDC Modification project, located along the ARDC

in Ascension and Livingston parishes, in the vicinity of Head of Island, Louisiana.

Prior studies and reports have documented degradation in the swamp adjacent to

the ARDC and have demonstrated a need for ecosystem restoration that simulates

historical hydrologic conditions. This project would establish hydrologic connectivity

between the ARDC and the western Maurepas Swamp, allowing the swamp to drain

during seasonal low-flow conditions in the Amite River and promoting the

germination and survival of the seedlings of bald cypress and other trees. This

connectivity would also allow nutrients and sediments to be introduced from the

ARDC into the swamp during flood events and from runoff during localized rainfall

events. Nutrients and sediment delivered to the swamp would improve biological

productivity and reduce the chances of further habitat deterioration. Finally, the

establishment of hydrologic connectivity would reduce the likelihood of the swamp

being converted to marsh or open water.

Louisiana contains one of the largest expanses of coastal wetlands in the contiguous

United States and accounts for 90 percent of the total coastal wetland loss occurring

in the Nation. The Maurepas Swamp complex is the second largest continuous

coastal forest in Louisiana, comprising over 190,000 acres of freshwater swamp

habitat. The LCA ARDC study area is an essential ecosystem since it includes

wetland habitats and provides high fish and wildlife value as well as habitat for

migratory birds and other aquatic organisms including threatened or endangered

species.

ES.2 NEED FOR AND OBJECTIVES OF ACTION*1

The natural processes of subsidence, habitat switching, and erosion of wetlands,

combined with a widespread human alteration, have increased rates of wetland loss

1 An asterisk denotes paragraphs that are required for National Environmental Policy Act (NEPA)

compliance.

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WRDA 2007 Section 7006(e)(3) ES-ii October 2010

and ecosystem degradation. Without action, Louisiana’s coastal ecosystem is not

sustainable. This loss of sustainability has manifested itself as accelerated land

loss. Coastal Louisiana is projected to lose an additional 328,000 acres of coastal

marshes, swamps, and barrier islands by the year 2050. The following ecosystem

functions are at risk:

• Vegetative habitat suitability and community diversity;

• Elevational maintenance and soil contribution from decomposing organic

material;

• Protection against substrate erosion;

• Water quality improvement;

• Nutrient uptake and carbon sequestration;

• Important nursery habitat;

• North American Central Flyway and North American Mississippi Flyway

waterfowl;

• wintering habitat; and

• Resting and feeding areas for neotropical migrants.

The natural hydrology within the study area has been modified by the construction

of the ARDC and a railroad grade. Sea-level rise and geological subsidence have

compounded the effects of these modifications. This has led to poor swamp health

and ecosystem degradation including surge-related saltwater intrusion;

impoundment of water; and lack of freshwater, sediment and nutrient input.

Functions of the freshwater swamp lost include habitat for wildlife and aquatic

species, recreational opportunities, aesthetics, and storm surge protection. Upon

severe degradation; the swamp will convert to freshwater marsh, then to open

water.

Investigation led to the establishment of the following planning objectives to be

implemented within the study area over the 50-year period of analysis:

• Increase hydrologic connectivity between the degraded swamp and

bottomland hardwood habitats within the study area and the ARDC by

increasing the exchange of freshwater, sediments, and nutrients over the

50-year period of analysis.

• Reduce habitat conversion of swamp to open water within the study area

over the 50-year period of analysis.

• Facilitate natural hydrologic cycle within the study area over the 50-year

period of analysis by reducing impoundment in degraded swamp and

bottomland hardwood habitats adjacent to the ARDC to improve tree

productivity and seedling germination.

• Improve fish and wildlife habitat within the study area over the 50- year

period of analysis.

The LCA ARDC Modification project is designed to be within the scope of the LCA

2004 report. The goal of the LCA Plan is to reverse the current trend of degradation

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WRDA 2007 Section 7006(e)(3) ES-iii October 2010

of the coastal ecosystem using restoration strategies that: reintroduce historical

flows of river water, nutrients, and sediment to coastal wetlands: restore coastal

hydrology to minimize saltwater intrusion; and maintain the structural integrity of

the coastal ecosystem (LCA, 2004).

ES.3 ALTERNATIVES*

PLANNING CONSTRAINTS

Specific Planning Constraints identified for the LCA ARDC Modification project

include the following:

Flood Control: The ARDC is a component of the AR&T (1956) flood control

channel. Project plans must not significantly decrease the performance and

original intent of the ARDC and the Amite River and Tributaries (AR&T)

project.

Designated Scenic Rivers: Blind River, located within the study area, is a

designated Scenic River. Designated Scenic Rivers are protected by a set of

use restrictions including channelization, clearing and snagging, channel

realignment, reservoir construction, and commercial cutting or harvesting of

trees or timber in violation of the Louisiana Scenic Rivers Act.

Hydroperiod: Water levels within the ARDC exhibit seasonal high channel

flow and low channel flow intervals. The natural variability of the

hydroperiod necessitates a project design that allows the project to function

as intended under a variety of flow regimes.

Other items that were taken into consideration during plan development and plan

selections include:

Drainage Infrastructure: Formulating a project design that does not

impair the capacity of the existing drainage system with additional waters

would help to ensure that residential flooding is minimized in the area.

Recreation: Minimize disruption of existing recreational use of the area and

ARDC vessel traffic to the extent practicable.

Existing Development: Existing residential structures and recreational

facilities along portions of the ARDC dredged material berms may pose

design challenges.

Water Quality: Planning objectives of the proposed project include the

periodic draining of the swamp during low-flow intervals in the channel and

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WRDA 2007 Section 7006(e)(3) ES-iv October 2010

flushing the adjacent habitat during high-flow intervals. Swamps may

release phosphorus sequestered within their substrates as well as other

constituents when subjected to a freshwater reintroduction. Project design

should minimize potential negative impacts to downstream water quality.

U.S. ARMY CORPS OF ENGINEERS (USACE) 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

National Environmental Policy Act (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. A further

discussion of how the alternatives were formulated for this project consistent with

the Environmental Operating Principles can be found in the main report.

WETLAND VALUE ASSESSMENT (WVA) MODEL

Wetland Value Assessment (WVA) models are ecological benefit models designed to

evaluate the existing, Future Without Project (FWOP), and Future With Project

(FWP) condition. The WVA produced Average Annual Habitat Units (AAHUs), a

measure of change, for the 50-year period of evaluation when comparing the FWP to

the FWOP. The Habitat Suitability Index (HSI) is a unitless number bounded by 0

and 1 where 0 represents no habitat and 1 represents optimum habitat.

The WVA calculates the benefits (FWP as compared to the FWOP) for years 0, 1, 10,

25, and 50. The habitat units for each from year 1 to year 50 are calculated. The

cumulative habitat units generated for the 50 year period of analysis (2012 - 2062)

divided by 50 will determine the AAHU. Thus the WVA accounts for tree growth

and the timing for ecological restoration.

ES.4 ALTERNATIVES*

A total of 105 structural and non structural measures and 45 alternatives were

considered and evaluated as part of the USACE planning process. All measures

and alternatives were evaluated for ecosystem benefits, cost-effectiveness, and

environmental impacts. Excluding the No-Action Alternative, the final array of

alternatives included seven options, each including openings in the north and/or

south banks of the ARDC, bifurcated conveyance channels, sidecasting of dredged

material in alternating berms along the proposed conveyance channels, cuts in an

existing railroad grade, and both dredged material berm and swamp floor

vegetative plantings.

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Recommended Plan

Alternative 33, which addresses the most-highly degraded portion of the study area,

has been chosen as the Recommended Plan. Alternative 33 is an implementable

element of the National Ecosystem Restoration (NER) plan, is within the cost and

scope of the authorization, has stand-alone utility, and can be justified based on

ecosystem restoration benefits.

Alternative 33 includes:

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

channel in the north bank of the ARDC also extending through the

railroad grade into NE-1 to add connectivity between NE-1, NE-2, and

the ARDC.

• Dredged material (5.0 acres) from the bank openings and the conveyance

channel would be sidecast in alternating berms so sheet flow is not

reduced.

• One cut would be created in the railroad grade approximately 0.9 of a

mile north of the ARDC to improve sheet flow.

• Vegetative plantings of bottomland hardwood/freshwater swamp tree

species on 5.0 acres of dredged material berms.

• Vegetative plantings of freshwater swamp tree species within 438 acres

of the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

Alternative 33 would meet the established objectives by:

• Restoring and benefitting 1,602 acres of freshwater swamp habitat;

• Creating a net of 679 AAHUs;

• Creating 5.0 acres of bottomland hardwood habitat;

• Establishing hydrologic connectivity between the ARDC and the western

Maurepas Swamp;

• Reducing the likelihood of the swamp being converted to marsh or open

water;

• Promoting the germination and survival of the seedlings of bald cypress

and other trees;

• Improving biological productivity and reducing further habitat

deterioration.

NATIONAL ECOSYSTEM RESTORATION (NER) PLAN

Alternative 39 was chosen to be the NER plan. This plan includes all the areas in

the final array including the areas with the critical need of restoration (have

already begun converting to marsh) and an additional area that is expected to need

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restoration in the next 20 years. This proposed action provides 1,602 average

annual habitat units for the impact areas and represents the long term restoration

need for the area. This plan exceeds the WRDA 2007 cost authorization. Features

of Alternative 39 include:

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

cut in the north bank of the ARDC also extending through the railroad

grade into NE-1 to add connectivity between NE-1 and NE-2.

• One dredged material bank opening and one bifurcated conveyance

channel in the south bank of the ARDC in SE-1 with the conveyance

channel extending through the railroad grade into SE-1 to add

connectivity between SE-1 and SE-2, and the ARDC.

• One opening and one conveyance channel in the south bank of the ARDC

in SE-1. Dredged material (9.9 acres) from the bank openings and the

conveyance channel would be sidecast on both sides of the proposed

channel. Gaps will be left in the disposal berms so sheet flow is not

reduced.

• Three cuts would be created in the railroad grade to improve sheet flow.

One cut would be approximately 0.9 miles north of the ARDC. The second

cut would be approximately 0.9 miles south of the ARDC. The third cut

would be approximately two miles south of the ARDC.

• Initial and secondary vegetative plantings of bottomland hardwood/

freshwater swamp tree species on 9.9 acres of dredged material berms.

• Initial and secondary vegetative plantings of freshwater swamp tree

species within 925 acres of the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

SEA LEVEL RISE

Within the LCA ARDC study area, sea-level rise is predicted to occur from 1.5 ft

(0.46 m) to 3.2 ft (0.97 m) over the 50-year period of analysis. In order to gauge the

effects of Relative Sea Level Rise (RSLR) on the selected plans, the WVA model was

run for Alternative 33 (Recommended Plan) and Alternative 39 (NER) over the 50-

year period of analysis. Section 3.8 of the report discusses the impacts of various

RSLR estimates on the benefits obtained for the Recommended Plan and NER

plans.

ES.5 AFFECTED ENVIRONMENT*

Climate, Geomorphic and Physiographic Setting: The study area is

located in the southeastern portion of Louisiana, approximately 30 miles southeast

of Baton Rouge, Louisiana. The climate is subtropical marine with long humid

summers and short moderate winters. The study area is susceptible to tropical

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waves, tropical depressions, tropical storms, and hurricanes. These cause

considerable property and environmental damage and loss of human life.

Hurricanes Katrina, Rita, Gustav, and Ike did not have a significant direct

impact on the study area; there was little wind and wave damage. These did have

an indirect effect due to the introduction of higher-salinity storm surge waters into

the impounded swamps within the LCA ARDC study area. This salt intrusion

reduces biomass production and impairs health, which increases tree mortality,

decreases soil production and integrity, and increases relative subsidence (Coastal

Wetlands Planning, Protection, and Restoration Act [CWPPRA] Task Force, 2002).

These higher-salinity storm surge waters become impounded by the dredged

material berms along the ARDC and are not drained from the swamps.

Consequently, salinity is increased in impounded waters and soils in the study area.

Increased connectivity through the ARDC dredged material berms would allow the

large headwater event that normally follows a tropical storm to flush the higher

salinity waters out of the swamp before it has an opportunity to infiltrate into the

substrate.

Soils and Waterbottoms: The study area is located in the Maurepas Basin,

a component of the Lake Pontchartrain Basin, located near the southern terminus

of the Mississippi Alluvial Plain physical province. Construction of the AR&T

(1956) flood control project, which includes the ARDC, has impacted the

geomorphology of the St. Bernard Delta complex.

Hydraulics and Hydrology: Hydrologic analyses within the study area

indicate that the ARDC and its dredged material berms have prevented the

adjacent bald cypress-tupelo swamp habitat from receiving nutrient and sediment

during high channel flow events and have prevented draining during low channel

flow events in the lower Amite River system.

Water Quality and Salinity: Human developments result in wastewater

and polluted runoff. The continued conversion of swamp habitat to marsh and

open water reduces natural filtration of water. Elevated salinities caused by

impoundment of storm-driven higher-salinity waters and the subsequent absorption

of salt into the substrate contribute to the degradation of the forested swamp and

its conversion to marsh and open water.

Air Quality: The study area was in nonattainment for the interval 2004-

2007 for ozone.

Noise: The noise from distant urban areas has little impact on the area. As

the population in the study area continues to grow, some noise pollution would

occur. The ambient noise caused by boat traffic and human activity in the ARDC,

Amite and Blind rivers may cause disturbances.

Vegetation and Wildlife Resources: The study area is considered “coastal

wetland,” which forms in sheltered coastal environments in conjunction with river

deltas, barrier islands, and estuaries. They are rich in wildlife resources and

provide nesting grounds and stopovers for waterfowl and migratory birds, as well as

spawning areas and valuable habitats for fish. Intertidal and subtidal bottoms are

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populated by communities of macrofauna whose structure is dependent upon

substrate, salinity, temperature, depth, and ecological relationships.

Benthic, Plankton, Fishery Resources and Essential Fish Habitat

(EFH): Construction of the ARDC and dredged material berms has prevented

exchange of organisms and water between the swamp and the ARDC.

The benthic community is seasonally abundant, typically during winter

months. Phyto-plankton, microscopic plants, and zooplankton can be found in the

vicinity of the ARDC and are important for their role in nutrient cycling and are a

major source of primary food-energy for most estuarine systems.

The fish species assemblage in the vicinity of the ARDC is primarily

composed of freshwater species, with occasional transient marine and diadromous

species.

The area provides some habitat for a few euryhaline species, but is not

classified as EFH.

Threatened and Endangered Species: The U.S. Fish and Wildlife Service

(USFWS), in a letter dated January 20, 2009, identified two threatened and

endangered species (Gulf sturgeon and West Indian manatee) and one delisted

species (bald eagle) that are known to occur within the area.

Cultural Resources: Five archaeological sites were identified within or

immediately adjacent to the study area, including a mound site on the Bayou Chene

Blanc bankside, shell middens on Bayou Chene Blanc (two sites) and ARDC (one

site north of the study area) banksides, and a shell midden and prehistoric scatter

on the lower Amite River bankside. The mound site on Bayou Chene Blanc could

not be located and is presumed to be destroyed. Two cultural resources were

identified: the railroad grade of the Garyville Northern Railroad (I6LVI 02) and the

Amite River Diversion Canal (16LV I03/I6AN84) (ARDC). Neither the ARDC nor

the railroad grade are eligible for the National Register of Historic Places.

Aesthetics: Aesthetic resources in the study area were negatively impacted

by hurricanes Katrina, Rita, Gustav, and Ike. Blind River is a designated Scenic

River. The study area encompasses approximately 24,000 acres of undeveloped

bald cypress-tupelo swamp habitat in the western Maurepas Swamp. The visual

complexity surrounding the study area’s waterfront properties, bayous, and coastal

swamp habitat provides a pleasing aesthetic to the public eye.

Recreation: Recreational activities such as hunting, trapping, and fishing

exist within the study area.

Socioeconomic Resources – Employment: Total employment in

Ascension and Livingston parishes is increasing. Employment and income resources

are primarily retail, and restaurants.

Socioeconomic Resources – Community Cohesion: The three

communities within the study area are Berthelot’s Campground, Waterfront East,

and Three Rivers Island. The three communities are internally homogeneous and

not related to each other.

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Socioeconomic Resources – Environmental Justice and Population:

Population in the vicinity of Head of Island has 30-40 percent minority composition.

The entire study area is characterized by poverty levels of less than 20 percent.

Socioeconomic Resources – Infrastructure: State and local roads,

railroad grade, overhead distribution lines, and underground telephone lines

traverse the study area.

Socioeconomic Resources – Business and Industry: Six businesses are

in the study area. Two unnamed local cypress lumber mills process logs extracted

from the region. A Recreational Vehicle (RV) park contains six covered spaces. The

Blind River Bar is located south of the ARDC at its confluence with the Blind River

and is accessible only by water.

Socioeconomic Resources – Traffic and Transportation: State and

local roads traverse the study area. Louisiana Highways 22 and 16 are the major

roads in the study area.

Socioeconomic Resources – Public Facilities and Services: The study

area is not serviced by a municipal sewer system. Wastewater Treatment of

Louisiana, Inc. provides sewer service to the two Blind River Properties

developments along the left descending bank of the ARDC. Properties within the

study area not served by private companies use septic systems.

Socioeconomic Resources – Local Government Finances, Community

and Regional Growth, Tax Revenue and Property Values: Increasing

population growth is resulting in increased local government finances, tax revenue

and property values. It is also increasing the community and regional growth.

Socioeconomic Resources – Agriculture and Forestry: Approximately

373 acres of agricultural lands, primarily livestock pastures are present. Little

timber harvesting occurs within the study area. However, submerged cypress logs

are extracted and processed by local timber mills. Recreational activities in the

study area include hunting for white-tailed deer, squirrels, rabbit and raccoons;

fishing for largemouth bass, bream, and crappie; and trapping alligators and nutria.

Some waterfowl hunting occurs in the WMA near the study area.

Merchantable size timber was found only on the ridges in the study area;

however, marketability was considered doubtful due to inaccessibility.

Socioeconomic Resources – Public Lands: A portion of the Maurepas

Swamp WMA is located within the southwestern study area. Recreational activities

in the WMA include hunting, fishing and trapping.

Socioeconomic Resources – Water Use and Supply: The study area for

this project lies on the Chicot Equivalent aquifer system, identified by the

Environmental Protection Agency (EPA) as a sole-source aquifer. The study area

also lies on the southern edge of both the Evangeline Equivalent aquifer system and

the Jasper Equivalent aquifer system

Socioeconomic Resources – Navigation: No Federal navigation channels

exist within the study area. The Amite River and Bayou Manchac Federal

navigation channel is present along the northwestern boundary of the study area.

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Navigable waterbodies within the study area include the ARDC, the Petite Amite

River, Blind River, and portions of Bayous Pierre and Chene Blanc.

Socioeconomic Resources – Oil, Gas, and Utilities: The western

Maurepas Swamp has undergone significant oil and gas exploration activity.

However, most oil and gas exploration and production activities in the region have

occurred southwest of the study area.

Socioeconomic Resources – Flood Control and Hurricane Protection

Levees: The AR&T flood control project was completed in 1964. Municipal and

parish flood control measures, including drainage canals and control structures are

present.

Socioeconomic Resources – Commercial Fisheries and Oyster Leases:

The fishes of the LCA ARDC study area primarily consist of freshwater species,

with occasional transient marine and diadromous species. There are no oyster

leases located within the study area.

Environmental and Hazardous Toxic and Radiological Waste

(HTRW): A limited HTRW survey and Phase I Environmental Site Assessment

were conducted for the study area to identify recognized environmental condition

(REC) sites or potential REC sites in connection with the study area. None of the

potential REC sites would be likely to expose the public or construction workers to

HTRW or to adversely affect the project.

ES.6 ENVIRONMENTAL CONSEQUENCES*

A comparison of the direct, indirect, and cumulative impacts for alternatives to

reverse the trend of degradation in the western portion of the Maurepas Swamp

was conducted. The No-Action Alternative is compared to the alternatives retained

for detailed analysis. The No-Action Alternative is considered to be the same as the

FWOP condition and analyzes the future conditions of the resource over a 50-year

period of analysis (2012-2062).

No-Action Alternative: Without Federal action, the swamp habitat

surrounding the ARDC would continue the eventual conversion from a freshwater

swamp to a freshwater marsh and open water. The direct impacts would be the

continued impoundment of swamp water within the study area, decreased

hydrologic connectivity, and a transition towards marsh and salinity-tolerant

vegetation. The demographics and economic conditions within the study area would

remain stable. Storm surges from tropical cyclone events would increase salinity

levels, and the frequency of saltwater inundation is expected to increase with RSLR.

Indirect impacts would be the decline of wildlife, fishery, and vegetative

resources. Flora and fauna species could experience stress due to saline waters not

being flushed from the system, and may change as salt-tolerant species replace

fresh water species. Existing swamp habitat would convert to water bottoms and

alter the benthic community, decreasing available nutrients and detritus. The

habitat quality would degrade, creating a stressful environment for species present.

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Diminished viewscapes for the study area would result. Existing and future

infrastructure present within the study area would be affected due to land loss. A

portion of the Maurepas WMA is the only public lands in the study area and would

be affected. There would be increased exposure of existing oil, gas, and utility

pipelines to coastal land loss which would increase operations, maintenance, repair,

replacement, and rehabilitation (OMRR&R) costs, as well as increase the required

investment in facilities and pipelines. Coastal forest habitat provides protection

from tropical cyclone events, consequently, there could be an increase in storm

surge and risk of flooding. Wetland loss would impact commercially important

species, including black drum, brown and white shrimp, and blue crab, leading to

declining abundances.

Cumulative impacts would be shoreline erosion and land loss resulting in a

projected conversion of 18,204 acres of swamp to fresh marsh and open water.

There would be decreased flows into and out of the swamp, increased water levels

due to coastal wetland loss and increased runoff due to increased urbanization of

the Pontchartrain Basin. The water and air treatment functions of wetlands would

subside. The integrity of existing recreational resources and aesthetics within the

study area would be endangered. Property values may fall as wetlands continue to

degrade. Public lands would be adversely affected. Localized storm surge and

storm wave damages are likely to increase. A loss of commercial fishery habitat is

likely. Impacts on all forms of vegetation include continued deterioration and loss

of vegetation and wetland habitat acreage. Continued nationwide wetland loss

would lead to increased acreage of shallow water bottoms. Benthic populations and

plankton would respond to perturbations with a shift towards saline-oriented

species. Land loss within the study area threatens the existence and integrity of

cultural and historic resources. Loss of vegetation would degrade the visually

complex environment and reduce opportunities for viewing wildlife. The

degradation and loss of wetlands would contribute to increased maintenance costs

of infrastructure. Current subdivisions within the study area may expand, creating

additional roads, bridges and utilities. As populations migrate to coastal

communities, investment in hurricane and flood control levees, pump stations, and

other flood control facilities are likely to increase.

Alternative 33 (Recommended Plan): Implementation of Alternative 33

(Recommended Plan) would reverse the conversion of swamp habitat to open water

and would improve 1,602 acres of swamp habitat and create 5.0 acres of upland

habitat within the study area.

Direct impacts would result from construction activities associated with the

removal of the existing dredged material berm, dredging of new conveyance

channels, and placement of dredged material to create bottomland hardwood

islands along conveyance channels. The appropriate Best Management Practices

(BMPs) would be implemented to limit introduction of sediments. Cutting through

the berms and stockpiling dredged sediments would directly impact water quality

by introducing sediments. Sediment introduction would temporarily increase total

suspended and dissolved solids, turbidity, as well as increase total metals and

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nutrients. There would be an increase in water flow into and out of the swamp

depending on ARDC stages, tidal activity and flow. Water level fluctuations would

occur in swamp habitats adjacent to ARDC. Restoring hydraulic connectivity would

temporarily and periodically allow impounded swamp waters that are low in

dissolved oxygen and high in biochemical oxygen demand (BOD), chlorides and

nutrients to enter the waterways. Vegetative plantings would necessarily involve

human access into areas that have rarely been disturbed. Fresh water would be

introduced into the forested swamp, reducing salinity, chloride, and total dissolved

solids concentrations. Initial and future periodic releases of waters of potentially

higher salinities from the impounded areas may impact the flowing water bodies by

temporarily increasing these parameters in the areas surrounding the cuts.

Ambient air quality impacts would be temporary and localized, resulting from

emissions of construction equipment, but would be negligible. Noise impacts may

impact fish and wildlife species, but these would generally avoid the construction

area. Construction activities would directly affect vegetation in the areas of the

new conveyance channels and cuts in the existing ARDC dredged material berm.

Riparian habitat would be created along the conveyance channels, and wetland

vegetation would be planted. Direct impacts to benthic resources and plankton

would be associated with construction activities including dredging and placement

of borrow material. Precautions have to be taken with regard to the Gulf sturgeon,

West Indian manatee and bald eagle. Viewscapes would temporarily be disturbed

by construction activities.

Indirect impacts would include improved hydrological connectivity between

the ARDC and the adjacent swamp. This would allow nutrients and sediments to

be introduced from the ARDC into the swamp during flood events and would

improve biological productivity and reduce the chances of further habitat

deterioration or conversion to marsh or open water. Dissolved organic compounds

and detritus would increase. The ARDC’s Fish and Wildlife Propagation use is

currently listed as impaired due to mercury, chloride and total suspended solids.

The release of swamp waters into the system may cause continued impairments.

Implementation is expected to improve water quality, thereby improving growth

and health of the cypress-tupelo forest. The cycle of inundation and drying of the

swamp would be partially restored, helping to prevent salt water intrusion and

degradation of the forested wetland. Particulates and gaseous air pollutants would

be reduced, increasing air quality. Smothering of benthic organisms may also occur

from dredge plume resettlement, but these impacts would be minimized through the

use of silt curtains or other measures. Increased nutrients and detritus would

provide increased benefits to plankton. Algal blooms may occur if phosphorus

sequestered in swamp sediments is released into surface waters. Land loss and

erosion prevented would benefit threatened cultural and historic resources in the

area. High quality emergent wetland viewscapes would increase visual complexity.

An increase in substrate quality would result in the preservation and retention of

existing infrastructure. Environmental easements would be placed within the areas

of impact. A restoration of coastal forest habitat would occur.

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Cumulative impacts would be the effects of this alternative with the additive

combination of impacts and benefits for overall net acres nourished and protected

by other Federal, state, local and private restoration efforts. A net total of 1,602

acres of wetland soils would be hydrologically restored and nourished; 2.6 acres of

soils along ARDC berms and 28.6 acres of existing swamp soils would be impacted

by the construction of conveyance channels; however these sediments would be used

to construct 5.0 acres of bottomland hardwood islands. The amount of deepwater

waterbottoms created from the construction of the conveyance channels would be

18.6 acres. Dissolved organic compounds and detritus from the swamp would

increase. The water purification function of a swamp would increase. Water

quality and the overall health of the forested swamp would improve. Noise levels

would return to preconstruction conditions. Upland habitat would be created and

would simulate existing upland and riparian habitat. Wetland creation and

nourishment would alter the plankton and benthic community and would result in

greater resources for these organisms. Appealing viewscapes supporting ecotourism as one travels Louisiana’s remote areas would be maintained. There would

be a reduced level of infrastructure damages and relocation compared to the NoAction Alternative. Environmental easements would be implemented within the

areas of impact. The restoration of the forest would result in localized storm surge

protection and a decrease in wave heights. Overall, the fishing industry would be

more stable near the study area due to a long-term increase in the quality of

fisheries habitat.

Alternative 34: Impacts resulting from the implementation of

Alternative 34 would be similar to those of Alternative 33 (Recommended Plan),

except 1,459 acres of swamp habitat would be improved and 2.7 acres of upland

habitat would be created.

Alternative 35: Impacts resulting from the implementation of

Alternative 35 would be similar to those of Alternative 33 (Recommended Plan),

except 820 acres of swamp habitat would be improved and 2.2 acres of upland

habitat would be created.

Alternative 36: Impacts resulting from the implementation of Alternative

36 would be similar to those of Alternative 33 (Recommended Plan), except 3,061

acres of swamp habitat would be improved and 7.8 acres of upland habitat would be

created.

Alternative 37: Impacts resulting from the implementation of

Alternative 37 would be similar to those of Alternative 33 (Recommended Plan),

except 2,279 acres of swamp habitat would be improved and 4.9 acres of upland

habitat would be created.

Alternative 38: Impacts resulting from the implementation of

Alternative 38 would be similar to those of Alternative 33 (Recommended Plan),

except 2,422 acres of swamp habitat would be improved and 7.2 acres of upland

habitat would be created.

Alternative 39: Impacts resulting from the implementation of

Alternative 39 would be similar to those of Alternative 33 (Recommended Plan),

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except 3,881 acres of swamp habitat would be improved and 9.9 acres of upland

habitat would be created.

ES.7 PUBLIC INVOLVEMENT*

The following public involvement has occurred during the study phase of this

project.

• A Notice of Intent (NOI) to prepare a Supplemental EIS (SEIS) for the

LCA ARDC Modification Feasibility Study was published on December 22,

2008.

• A public scoping meeting was held in accordance with NEPA on February

12, 2009.

• A meeting was held with Mr. Glen Martin, part owner of Blind River

Properties Inc. and majority land owner within the LCA-ADRC study

area, on August 31, 2009, in which preliminary project alternatives were

presented to gain his input.

• A second public meeting was held on June 24, 2010 in French Settlement

Louisiana.

• Both the Lake Pontchartrain Basin Foundation and the Coalition to

Restore Coastal Louisiana expressed support for the LCA ARDC

Modification project in a joint letter to the commander of the New Orleans

office of the USACE, February 20th

• On November 2, 2009 a meeting was held with the Louisiana

Conservation Fund (LCF) and the Audubon Society at their request to

discuss LCA ARDC efforts.

, 2009.

• Separate meetings were held between representatives of Ascension and

Livingston Parish and members of the LCA ARDC PDT on August 6, 2009

and February 4, 2010 in order to solicit feedback on the project objectives

and to report on the progress to date. Continual coordination between the

LCA ARDC Project Delivery Team (PDT) and Parish representatives has

occurred. Additional meetings have been held with Livingston Parish to

prepare for the potential coordination between the Hydrologic Restoration

in Swamps West of Lake Maurepas CIAP and the LCA ARDC projects.

The Integrated Feasibility Report and Supplemental Environmental Impact

Statement was released to the public in May 2010, followed by a 45-day public

review period.

ES.8 COORDINATION AND COMPLIANCE*

Following completion of the Final Integrated Report, the Assistant Secretary of the

Army for Civil Works will most likely issue a ROD concerning the proposed action.

Full compliance with statutory authorities will be accomplished upon review of the

Final Integrated Feasibility Report and SEIS by appropriate agencies and the

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public and the signing of the ROD, in compliance with NEPA. The USACE has

coordinated with the U.S. Fish and Wildlife Service, National Marine Fisheries

Service and the Louisiana Department of Wildlife and Fisheries as per the Fish and

Wildlife Coordination Act. A final Coordination Act Letter Report has been

received.

ES.9 AREAS OF CONTROVERSY AND UNRESOLVED ISSUES

Meetings and discussions with the public and local, state and federal agencies and

the Project Development Team (PDT) indicate support for the project and did not

identify any areas of controversy or unresolved issues. The implementation of the

recommended plan (Alternative 33) would result in long-term, sustainable

ecosystem restoration. Fish and wildlife habitat would be restored and maintained.

The project outputs are cost-effective and consistent with the Recommended Plan.

This plan is acceptable to the public and the State of Louisiana.

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

at this time. 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. 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.10 CONCLUSIONS AND RECOMMENDATIONS*

The recommended plan (Alternative 33) includes the creation of three conveyance

channels through the dredged material berm of the ARDC to improve connectivity

that would increase the movement of freshwater, sediments, and nutrients to and

from the cypress-tupelo swamp. This plan is both cost-effective and

environmentally beneficial and addresses the most critical habitats in the study

area. The recommended plan would create 679 AAHU, restore 1,602 acres of

cypress-tupelo swamp habitat and create 5.0 acres of bottomland hardwood habitat.

The MCACES fully funded cost is estimated at $8,540,000 and the average

annualized cost per AAHUs is estimated to be $660. This restoration would benefit

fish and wildlife resources, freshwater swamp habitat, and improve water quality.

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WRDA 2007 Section 7006(e)(3) ES-xvi October 2010

The overall benefits of the recommended plan justify the estimated costs for project

implementation. This project would be cost shared by the non-Federal sponsor, the

Coastal Protection and Restoration Authority (CPRA) at 35 percent non-Federal

and 65 percent Federal. The total Federal share would be $5,610,000 and the nonFederal share would be $2,930,000. Additionally, the non-Federal sponsor will be

100 percent responsible for the OMRR&R costs of the project which is estimated to

be $10,000 annually. Monitoring costs, which are estimated to be $2,970,000 over

10 years would be cost shared at 35 percent non-Federal and 65 percent Federal.

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Study Information Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 1-1 October 2010

1.0 STUDY INFORMATION

1.1 STUDY AUTHORITY

The Amite River Diversion Canal (ARDC) Modification project was identified in the

Louisiana Coastal Area (LCA), Louisiana Ecosystem Restoration Study (USACE

2004; 2004 LCA Plan). The 2004 LCA Plan was recommended to Congress by a

Chief of Engineers report dated January 31, 2005, which called for a coordinated,

feasible solution to the identified critical water resource problems and opportunities

in coastal Louisiana.

The 2004 LCA Plan and the January 2005 Chief of Engineers report included the

following recommendations:

1. Specific Congressional authorization for five near-term critical restoration

features,

2. Programmatic authorization of various programs, demonstration projects

and investigations.

3. Approval of investigations and preparation of necessary feasibility-level

reports for 10 additional near-term critical restoration features, for future

potential Congressional authorization. The ARDC Modification project

was included in this list of 10 additional projects.

Title VII of the Water Resources Development Act (WRDA) 2007: (Public Law 110-

114, 121 STAT. 1270) authorizes the LCA program. In total, the LCA program has

authority for 25 projects falling into various components including investigations,

research, demonstrations, and construction. The authority includes requirements

for comprehensive coastal restoration planning, program governance, project

modification investigations, a Science and technology (S&T) program, restoration

project construction, a program for beneficial use of dredged material, feasibility

studies for restoration plan components, and other program elements. The 10

projects recommended in the 2004 LCA Plan for further analysis and conditionally

authorized for construction by WRDA 2007. Furthermore, the six projects listed

under Sec 7006(e)(3) were provided with the conditional construction authorization

pending a favorable Chief’s Report by December 31, 2010.

According to WRDA 2007 the study authority is the following:

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.

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WRDA 2007 Section 7006(e)(3) 1-2 October 2010

SEC 7006. CONSTRUCTION.

. . . (e) ADDITIONAL PROJECTS. —

. . . (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 paragraph (2) or paragraph

(3), as the case may be, has not been approved by resolutions adopted by the

Committee on Transportation and Infrastructure of the House of

Representatives and the Committee on Environment and Public Works of the

Senate.

WRDA Implementation guidance for the 7006(e)(3) studies was issued in July of

2009 and directs the 7006(e)(3) studies to have a favorable Chief’s Report by

December 2010. The guidance did not discuss the 2008 report requirement.

Nevertheless in 2008, U.S. Army Corps of Engineers, Mississippi Valley Division,

New Orleans MVN provided ASA with a letter report for Congress informing them

MVN would not be submitting a report in 2008, but would be complying with the

2010 deadline set forth in WRDA 2007.

WRDA Section 7003 directs that the projects would be carried out substantially in

accordance with the 2005 Chief of Engineers report. The 2004 LCA Ecosystem

Restoration report recommended the following action for the Louisiana Coastal

Area Amite River Diversion Canal (LCA ARDC) Modification project:

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WRDA 2007 Section 7006(e)(3) 1-3 October 2010

Increase Amite River Diversion Canal influence by gapping banks

This restoration feature involves the construction of gaps in the existing

dredged material banks of the Amite River Diversion Canal. The

objective of this feature is to allow floodwaters to introduce additional

nutrients and sediment into western Maurepas Swamp. The exchange of

flow would occur during flood events on the river and from the runoff of

localized rainfall events. This feature would provide nutrients and

sediment to facilitate organic deposition in the swamp, improve

biological productivity, and prevent further swamp deterioration.

Prior studies and reports have documented degradation in the swamp adjacent to

the ARDC and have demonstrated a need for ecosystem restoration that simulates

historical hydrologic conditions. This project would evaluate different methods for

establishing hydrologic connectivity between the ARDC and the western Maurepas

Swamp, allowing the swamp to drain during seasonal low-flow conditions in the

Amite River and promoting the germination and survival of the seedlings of bald

cypress and other trees. This connectivity would also allow nutrients and

sediments to be introduced from the ARDC into the swamp during flood events and

from runoff during localized rainfall events. Nutrients and sediment delivered to

the swamp would improve biological productivity and reduce the chances of further

habitat deterioration. Finally, the establishment of hydrologic connectivity would

reduce the likelihood of the swamp converting to marsh or open water.

In keeping with the LCA goals, the LCA ARDC Modification project is an ecosystem

restoration project which focuses on near-term solutions. Delaying any proposed

restoration action could result in a loss of restoration opportunities and could limit

the benefits available for this project.

This project would complement but is independent of two other proposed LCA

projects (LCA Small Diversion at Hope Canal and LCA Small Diversion at

Convent/Blind River) and two proposed Coastal Impact Assistance Program (CIAP)

projects (Hydrologic Restoration in Swamps West of Lake Maurepas and Bald

Cypress/Tupelo Coastal Forest Protection (Not illustrated in Figure)) (Figure 1.1).

The LCA ARDC Project Delivery Team (PDT) coordinated with the staff of these

other projects to identify all known interactions between projects.

1.2 PURPOSE AND SCOPE

This document serves as the Integrated Feasibility Report and National

Environmental Policy Act (NEPA) documentations for the Louisiana Coastal Area

Amite River Diversion Canal (LCA ARDC) Modification project. Section 7006(e)(3)

of the WRDA 2007, Ecosystem Restoration Projects Study (hereafter referred to as

the LCA ARDC Supplement Environmental Impact Statement [SEIS]) outlines the

study elements requiring Congressional reporting that will be undertaken in

51
22 

Lake Maurepas

Lake

Pontchartrain

Mississippi

River

Mississippi River

Ami te Rive r

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: April 2010Scale:

Source: NAIP/GEC

RELATED PROJECTS IN VICINITY OF

AMITE RIVER DIVERSION CANAL MODIFICATION Figure: 1.1

1:220,000

Map ID: 27850108-1381

Texas Mississippi

Arkansas

Legend

LCA Amite River Diversion Canal Study AreaCIAP Hydrologic Restoration in Swamps West of Lake MaurepasLCA Small Diversion at Convent/Blind RIverLCA Small Diversion at Hope Canal

±

01234

Miles Image: 2007 Ascension, Livingston, St. James, St. John, and Tangipahoa Parishes USDA-FSA-APFO NAIP MrSID Mosaic

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Study Information Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 1-5 October 2010

partnership between the United States Army Corps of Engineers (USACE) and the

State of Louisiana.

The LCA ARDC Feasibility Study is being developed as a supplement to the LCA

Louisiana - Ecosystem Restoration: Comprehensive Coast-wide Ecosystem

Restoration Study (LCA Near-term Restoration Plan) and is intended to meet the

requirements of the Section 7006(e) of the WRDA 2007. This feasibility study is

anticipated to result in a Chief of Engineers Report containing a recommended plan

(Plan). The Plan addresses systematic restoration of bald cypress-tupelo swamp in

areas affected by the Amite River Diversion Canal (ARDC), and considers measures

to reduce future bald cypress-tupelo swamp degradation and conversion, restore

sheet flow impaired by dredged material bank construction, and protect vital

socioeconomic and public resources. The Plan addresses ecosystem restoration

exclusively, and does not impair or alter the flood control capabilities of the ARDC.

The Plan is independent of, but synergistic with, other LCA near-term critical

features, as well as coastal restoration projects proposed under other authorities to

provide a holistic approach to restore impaired swamp habitat in the western

Maurepas Swamp (see section 1.5).

The environmental consequences of the proposed project are evaluated in Section 5

of this report. The integrated NEPA documentation/SEIS presented here is a

supplement to the Final Programmatic Environmental Impact Statement, LCA

Ecosystem Restoration Study (FPEIS). The Record of Decision (ROD) for the FPEIS

was signed on November 18, 2005. The FPEIS is hereby incorporated by reference.

1.3 STUDY AREA

In the 1950s, the USACE, in an effort to relieve flooding along the upper Amite

River, authorized the construction of the ARDC to enhance the flow of water from

the meandering Amite River to Lake Maurepas. The 10 mile long canal is 300 feet

wide and was dug to a depth of 25 feet. The LCA ARDC study area (Figures 1.2 and

1.3) is located in LCA Subprovince 1 (USACE 2004) and is situated along the ARDC

in Ascension and Livingston Parishes, in the vicinity of Head of Island, Louisiana.

The study area is bounded to the north by the old channel of the Amite River, Old

River, Chinquapin Canal and Bayou Chene Blanc; to the east by the Blind River; to

the south by the Petite Amite River and the New River Canal; and to the west by

the Sevario Canal, Ascension Parish flood protection levees, and the Laurel Ridge

Canal; and is located in the following sections:

• Township 9 South, Range 4 East, Sections 9-16, 22-27, and 34-36;

• Township 9 South, Range 5 East, Sections 7, 14-36;

• Township 9 South, Range 6 East, Section 30;

• Township 10 South, Range 4 East, Sections 1-3 and 10-12; and

• Township 10 South, Range 5 East, Sections 2-11.

53
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:Source: USDA/GEC

STUDY AREA REGION

Map ID: 27850108-1781

Lake

Maurepas

Lake

Pontchartrain

22

Mississippi River

Iberville

Parish

Amite River Diversion Canal

Blind River

Amite River

Amite River

Livingston Parish

Ascension Parish

St. John the Baptist Parish

Tangipahoa

Parish

St. James Parish

East Baton

Rouge Parish

10

12

61

51

22

444

70

16

42

74

447

621

30

63

928 931 44

431

1037

933

941

426

429

932

929

641

934

935

1026

1033

3115

1039

427

1038

937

930

936

43

938

441

1032

42

22

42

22

73

429

42

18

942

61

405

55

Killian

Garyville Reserve

Baton Rouge

Gonzales

Sorrento

St.

Gabriel

French

Settlement

Port

Vincent

Springfield

Lutcher

1:260,000

0246 1

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study AreaCities and TownsParishesWater Bodies

Figure: 1.2

54
Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: July 2010Scale:Source: USDA/GEC

STUDY AREA AND SUBUNITS

Map ID: 27850108-1780

Little Bayou

Chene Blanc

Bayou C hene Blanc NW-2

SE-1

SW-2

NE-2 NE-1

SE-2

NE-3

Blind River

Amite River Diversion Canal

New River Canal

Petite Amite River

Chinquapin Canal

NW-1

SW-1

Weir

Old RailroadEmbankment

Laurel Ridge

Canal

Flat

Lake

Petite A mite R vi r e

Alligator Bayou

Bayou An ot ni e

Bayou Chene Blanc

New River

O ld River

Petite Amite River

a B you i P er er

Ba oy V u ci knair

Heath Bayou

1:80,000

±

0 0.5 1 1.5 2

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study Area SubunitsMaurepas Swamp Wildlife Management Area

Figure: 1.3

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Study Information Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 1-8 October 2010

For planning purposes, the LCA ARDC study area has been divided into nine

separate hydrologic subunits. Each subunit was developed based on hydrologic

differences (Appendix L) that exist throughout the study area due to natural and

manmade hydrologic boundaries (Table 1.1). These boundaries include natural

topography such as natural ridges and waterways, as well as manmade features

such as dredged material berms and waterways.

1.4 HISTORY OF INVESTIGATION

In 1999, the State of Louisiana and the Federal agencies charged with restoring and

protecting Louisiana’s coastal wetlands released a plan to restore coastal Louisiana

entitled “Coast 2050: Toward a Sustainable Coastal Louisiana” plan. In response

to the Coast 2050 Plan USACE developed the May 1999 report, entitled Section

905(b) ([Water Resource Development Act] (WRDA) 1986) Analysis Louisiana

Coastal Area, Louisiana -- Ecosystem Restoration. This reconnaissance-level effort

evaluated the Coast 2050 Plan as a whole and expressed a Federal interest in

proceeding to the feasibility phase. In 2000, it was envisioned that a series of

feasibility reports would be prepared over a 10-year period. As a result, the USACE

and the State of Louisiana initiated the Louisiana Coastal Area (LCA)

Comprehensive Coastwide Ecosystem Restoration Study to coordinate the separate

studies. In FY 2004, recognition of Federal and state funding constraints and

scientific and engineering uncertainties pertaining to some of the restoration

features under consideration led to the determination that the coastal area

ecosystem restoration effort should begin with the development and implementation

of a restoration plan that identifies highly cost effective restoration features that

address the most critical needs of coastal Louisiana, as well as large-scale and longterm restoration concepts. The resulting near term restoration plan was released in

2004 as the LCA, Louisiana Ecosystem Restoration Study. This study was identified

in the 2004 LCA report and authorized by WRDA 2007. The previous reports and

plans are further described in Section 1.5.

In November 2008, the USACE and the State of Louisiana represented through the

Coastal Protection and Restoration Authority (CPRA) executed a single Feasibility

Cost-Share Agreement (FCSA) covering the six LCA near-term plan projects listed

in Section 7006(e) of the WRDA 2007. The six features each underwent a separate

feasibility analysis and environmental compliance review.

1.5 PRIOR REPORTS AND EXISTING PROJECTS

A number of prior water resources development efforts are relevant to the LCA

Near-term Restoration Plan. Table 1.2 lists these efforts and denotes how each is

relevant to the ARDC, Louisiana study followed by a discussion of each report or

project.

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Table 1.1. Hydrologic Subunits

Hydrologic

Subunit Acres Description

NW-1 2,332

This subunit is one of the healthier portions of the western Maurepas

Swamp and is connected hydrologically by Bayou Pierre and the Amite

River. This area also contains an extensive housing development. It is

surrounded by Old River to the north, the ARDC to the south, and a

developed natural ridge to the east.

NW-2 4,289

This subunit contains the healthiest portion of the western Maurepas

Swamp. It is surrounded by Old River to the north, the ARDC to the

south, a developed natural ridge to the west, and a natural ridge to the

east. It is connected hydrologically by Old River and the Petite Amite

River.

NE-1 3,351

This subunit exhibits some degradation and has little to no hydrologic

connectivity with the ARDC, but is hydrologically connected by Bayou

Chene Blanc and the Chinquapin Canal. The subunit is surrounded by the

Chinquapin Canal to the north, the ARDC to the south, an abandoned

railroad embankment to the east, and an undeveloped natural ridge to the

west

NE-2 2,309

This subunit has a high degree of habitat degradation and has little to no

hydrologic connectivity with the ARDC. The subunit is surrounded by the

Chinquapin Canal to the north, an abandoned railroad embankment to the

west, the ARDC to the south, and Little Bayou Chene Blanc and Blind

River to the east. This subunit is highly degraded and is one of the areas in

most need of restoration.

NE-3 358

This subunit has some degree of habitat degradation and is hydrologically

connected by Bayou Chene Blanc, Little Bayou Chene Blanc. A portion of

Blind River, which is hydrologically connected to this subunit as well,

borders to the south.

SW-1 1,300

This subunit contains a series of culverts that provide hydrologic

connectivity between the swamp and the ARDC and is one of the healthier

portions of the western Maurepas Swamp. The subunit is bordered by the

ARDC to the north and natural ridges to the south and west.

SW-2 8,106

This subunit appears to have some areas of degradation along with some

areas of healthy swamp. The subunit is hydrologically connected by the

Petite Amite River to the east and New River Canal to the south. It is also

bordered by the ARDC to the north, and a developed natural ridge to the

west.

SE-1 4,875

This subunit exhibits some degradation, mainly due to the lack of

freshwater, sediment, and nutrient input caused by the ARDC dredged

material berms. This subunit is hydrologically connected by Blind River on

the south and the Petite Amite River to the west side. This subunit is

bordered by the ARDC to the north and an abandoned railroad

embankment to the east.

SE-2 1,062

This subunit exhibits some degradation, mainly due to the lack of

freshwater, sediment, and nutrient input caused by the ARDC dredged

material berms. The subunit is surrounded by the ARDC to the north, an

abandoned railroad embankment to the west, and Blind River to the east.

This subunit is highly degraded and is one the areas in most need of

restoration.

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Table 1.2. Relevance of Prior Studies, Reports, Programs, and Water

Projects to the LCA ARDC Integrated Feasibility Report and EA

Prior Studies, Reports, Programs,

and Water Projects

Relevance to LCA ARDC

Data Source

Consistency

Structural

Measures

NonStructural

Measures

Future

Without

Project

Condition

Comprehensive Planning Studies

Coast 2050, 1999 X XX

LCA Near-term Restoration Plan, 2004 X XXX X

Louisiana’s Comprehensive Master Plan for a Sustainable

Coast, 2007 X XXX X

Louisiana Coastal Protection and Restoration (LACPR),

2009 X XX

Prior Studies, Reports and Water Projects

Amite River and Bayou Manchac, 1928 X X X

Mississippi River and Tributaries (MR&T), 1928 X X X

Amite River and Tributaries (AR&T), 1956 X X X

Comite River Diversion X X X

LCA Near Term Critical Restoration Features

• LCA Small Diversion at Hope Canal (1,500 – 2,000

cfs) X XXX X

• LCA Small Diversion at Convent/Blind River

(1,000 – 5,000 cfs) X XXX X

Coastal Impact Assistance Program (CIAP) Projects

• Hydrologic Restoration in Swamps West of Lake

Maurepas X XXX X

• Bald cypress/Tupelo Coastal Forest, Pontchartrain

Basin X XXX X

CWPPRA Projects Authorized for Design X XXX X

Related Laws and Programs

Louisiana Coastal Management Program, 2008 X X

Louisiana Coastal Wetlands Conservation, Restoration

and Management Act, 1989 X X

The Coastal Wetlands Planning, Protection and

Restoration Act (CWPPRA), 1990 X XXX X

The Coastal Impact Assistance Program (CIAP), 2001 and

2005 X XXX X

Act 8 of the First Extraordinary Session of 2005 X X

Various Plans and Programs of Non-Government

Organizations X XX X

1.5.1 Federal

Amite River and Tributaries (AR&T), 1956: The ARDC was authorized by

Congress in 1956 as a component of the AR&T Federal flood control project. The

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ARDC was constructed from mile 25.3 of the Amite River to mile 4.8 of the Blind

River. The ARDC is 10.6 miles long, 300 feet wide, and was originally dredged to 25

feet deep. The ARDC is connected to the Amite River by a control weir at French

Settlement that was designed to retain low flows in the Amite River. A small

navigation channel through the control weir allows small boats to pass to and from

the river and the ARDC. Maintenance of portions of the AR&T within their

respective boundaries is the responsibility of the Ascension and Livingston Parish

Councils and the East Baton Rouge Parish Council. Construction of this project was

initiated in 1957 and completed in 1964. No dredging activities have occurred in

the ARDC since its construction. The dredged material berms created alongside the

ARDC as a result of this project provide interference with natural hydrologic

exchange within the LCA ARDC study area.

CWPPRA Project Priority Lists: Coastal Wetlands Planning, Protection and

Restoration Act (CWPPRA), often referred to as simply “The Breaux Act,” was the

first Federally mandated restoration effort to take place along Louisiana’s coast and

the first program to provide a stable source of Federal funds dedicated specifically

to coastal restoration.

Various ARDC modification projects have been proposed to the CWPPRA including:

 CWPPRA’s PPL 12 Proposal, 2002: This initial proposal involved cutting

five to 10 gaps in the dredged material berms on both sides of the diversion

canal and installing 36-inch or 48-inch culverts at the gap locations for the

purpose of facilitating water exchange to increase productivity, regeneration,

and sediment accretion within the adjacent cypress and tupelo swamps, and

to increase dissolved oxygen in water flowing through the adjacent swamp

habitat.

 CWPPRA PPL 16 Proposal, 2006: A proposal for gapping the dredged

material berms of the ARDC was again submitted to the CWPPRA Task

Force for consideration for the PPL 16 on 5 January 2006. The proposal

involved the construction of 5 to 10 gaps in the dredged material berms on

both sides of the ARDC to facilitate water exchange, while also presenting

the option of placing two of the proposed gaps on the banks of the Petite

Amite River north of the existing bridge, to avoid existing development along

the western portion of the ARDC.

 CWPPRA PPL 17 Proposal, 2007: A proposal for gapping the dredged

material berms of the ARDC was submitted to the CWPPRA Task Force for

consideration for the 17th Priority Project List (PPL 17) on 11 January 2007.

The proposal features differed markedly from those of the PPL 12 proposal.

The PPL 17 proposal involved the construction of numerous gaps in the

dredged material berms of the ARDC, the old railroad grade that traverses

the areas of impact to the north and south, and the levees of the Blind River

and the Petite Amite River along the study area border to facilitate water

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WRDA 2007 Section 7006(e)(3) 1-12 October 2010

exchange. The proposal indicates that the gaps would be located to maximize

water exchange.

Coast 2050 Plan, 1998: In 1998, Federal and state agencies, local governments,

academia, numerous non-governmental groups, and private citizens participated in

developing the Coast 2050 Plan. The Plan built upon lessons learned through the

CWPPRA and other programs. It 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 for the LCA

Ecosystem Restoration Study.

LCA Ecosystem Restoration Study, 2004: In 2000, the Nation and State of

Louisiana initiated the LCA Ecosystem Restoration Study to address Louisiana’s

severe coastal land loss problem. The goal of LCA study was to achieve and sustain

a coastal ecosystem that can support and 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 Final Programmatic Environmental Impact Statement,

LCA, Louisiana, Ecosystem Restoration Study was prepared for this study. The LCA

ARDC project was identified as a near-term critical restoration feature of the LCA

Ecosystem Restoration Plan.

• LCA Small Diversion at Hope Canal: The LCA Small Diversion at

Hope Canal is located east of the project. The LCA Small Diversion at

Hope Canal consists of diverting approximately 1,500 to 2,000 cfs from

the Mississippi River into the Hope Canal at Garyville. The Hope Canal

will be improved and water management features will be included to

distribute the flow into the Maurepas Swamp. The project service area is

approximately 36,000 acres (56.25 square miles). The project is currently

being investigated under the CWPPRA program as PO-29 River

Reintroduction to Maurepas Swamp. The work for this project has not

yet begun under the LCA program.

This project will benefit a different portion of the Maurepas swamp than

the LCA ARDC Modification project. Both of the projects are independent

but their effects will be additive in restoring the swamp. Figure 1.1

displays the current project still under CWPPRA.

• LCA Small Diversion at Convent/Blind River: The LCA Small

Diversion at Convent/Blind River project is located south of the project

area. The LCA Small Diversion at Convent/Blind River project consists

of diverting approximately 1,000-5,000 cfs from the Mississippi River

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into the Blind River and the Maurepas Swamp. The objective of this

feature is to introduce sediment and nutrients into the swamp to reverse

swamp decline in that area.

The LCA ARDC modification project will restore a different portion of the

Maurepas swamp than the Small Diversion at Convent/Blind River

project (Figure 1.1). The study areas for both projects are hydrologically

independent; therefore any proposed actions would not result in

ecosystem benefits or impacts between the two projects. The ARDC will

add to the restoration benefits of the LCA Small Diversion at Convent

Blind River and Small Diversion at Hope Canal projects. All projects will

aid in restoring the second largest stand of continuous swamp in

Louisiana.

USACE Amite River Diversion Channel Spoil Bank Gapping Preliminary

Restoration Plan, 2004: This project was a USACE restoration project under

Section 1135. A Preliminary Restoration Plan was developed and completed, but the

project went unfunded. This project was to gap the northern dredged material

berms in an effort to reintroduce ARDC water into the adjacent swamps.

Louisiana Coastal Protection and Restoration (LACPR), 2009: In 2006,

Congress authorized development of a Technical Report for coastal restoration and

“Category 5” hurricane risk reduction in south Louisiana. The USACE submitted a

Preliminary Technical Report to Congress in July 2006. A Final Technical Report

completed in 2009 includes different structural alignments and measures such as

floodgates, floodwalls, and levees. The report includes nonstructural measures such

as elevating homes. In addition, the report reviews various wetland restoration

measures and highlights the role of wetlands in coastal risk reduction.

Coastal Impact Assistance Program (CIAP) Projects, 2008: The Energy

Policy Act of 2005 was signed into law on August 8, 2005. Section 384 of the Act

establishes the CIAP which authorizes funds to be distributed to Outer Continental

Shelf (OCS) oil and gas producing States to mitigate the impacts of OCS oil and gas

activities. CIAP projects located within or near the LCA ARDC study area include:

 Hydrologic Restoration in Swamps West of Lake Maurepas (CIAP):

This proposed project would be located within portions of the LCA ARDC

Modification project study area. The CIAP project received study funding in

September 2010 to begin design but has not yet been awarded construction

funding. The CIAP project proposes to facilitate water exchange between the

ARDC and portions of the adjacent Maurepas Swamp. Additionally, the

project proposes to facilitate better hydraulic conductivity between portions of

the interior Maurepas Swamp and the ARDC. The LCA ARDC Modification

project PDT, the CIAP project team, and representatives of Livingston Parish

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have coordinated these separate efforts to ensure that implementation of the

proposed CIAP project and the LCA ARDC Modification project would result

in the maximum benefits for the Maurepas Swamp area. Based on the

aforementioned coordination, once the CIAP project is authorized for

construction funding, the actions proposed by this project will represent a

separate effort from the actions recommended by the LCA ARDC

Modification project. To date no formal request for the use of CIAP funds as

a cost share for this project has been made.

 Bald cypress/Tupelo Coastal Forest, Pontchartrain Basin (CIAP): This

proposed CIAP project would be located nearby the LCA ARDC study area.

The project proposes to purchase a portion of the existing bald cypress-tupelo

swamp in the western Maurepas Swamp northeast of the study area to

protect the habitat from future logging. This CIAP project was awarded

funding for initial work including land appraisal and legal documents

however has not yet been awarded final funding to acquire land.

1.5.2 State

Integrated Ecosystem Restoration and Hurricane Protection: Louisiana’s

Comprehensive Master Plan for a Sustainable Coast, 2007: Act 8 of the First

Extraordinary Session of the 2005 Louisiana Legislature established the CPRA to

develop, implement, make reports on, and provide oversight for a comprehensive

coastal protection master plan and annual coastal protection plans. The report

Integrated Ecosystem Restoration and Hurricane Protection: Louisiana’s

Comprehensive Master Plan for a Sustainable Coast (Master Plan) was developed

to fulfill the mandates of Act 8, which was signed into law in November 2005. The

Master Plan presents a series of recommended hurricane protection and coastal

restoration measures that, taken together, present a conceptual vision of a

sustainable coast based on the best available science and engineering. Measures

presented in the plan are divided into three groups: restoring sustainability to the

Mississippi River Delta; restoring sustainability to the Atchafalaya River Delta and

Chenier Plain; and hurricane protection (structural and non-structural measures).

The LCA ARDC project is consistent with restoring sustainability to the Mississippi

River Delta.

1.6 PLANNING PROCESS AND REPORT ORGANIZATION

The LCA ARDC Modification project follows the United States Army Corps of

Engineers (USACE) 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 (FS/SEIS) includes elements of both the planning

process and sections specific to the NEPA review of the project.

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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 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

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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, contingency mission execution in a

world-wide 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.

• 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.

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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 project addresses two points of the USACE Campaign Plan. The second goal of

the USACE Campaign Plan is addressed by this project since it is an element of the

LCA ecosystem restoration plan on the Gulf Coast and is part of a collaborative

effort with the non-Federal sponsor. This project 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

This section presents the results of the first step of the planning process, the

specification of problems and opportunities and the establishment of planning

objectives and planning constraints, which is the basis for the formulation of

alternative plans. The 2004 LCA problems, needs, opportunities and objectives are

presented along with the specific problems, needs, opportunities and constraints

identified for the LCA ARDC study area project.

2.1 NATIONAL OBJECTIVES

The U.S. Army Corps of Engineers (USACE) planning process is based on the

economic and environmental Principals and Guidelines (P&G) promulgated in 1983.

The P&G provide for development of reasonable plans that are responsive to

National, State, and local concerns. Planning project benefits are quantified in this

process as national economic development (NED) output, national ecosystem

restoration (NER) output, or a combination of NED/NER output.

For water and land resources planning, the Federal objective is to contribute to

NED while protecting the Nation's environment and adhering to national

environmental statutes, executive orders, and Federal planning requirements.

NED contributions are increases in the net value of the national output of goods

and services, expressed in monetary units. These NED outputs are the direct net

benefits that accrue in the planning area and the rest of the Nation. Contributions

to NED may include increases in the net value of marketed and non-marketed

goods and services.

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 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.

Multipurpose plans that include ecosystem restoration shall contribute to both NED

outputs and NER outputs. For multipurpose projects, a plan that trades off NED

and NER benefits to maximize the sum of net contributions to NED and NER is

usually recommended.

NER contributions were considered in the alternatives analysis for this project. As

specified, under Title VII of Water Resource Development Act (WRDA) 2007, any

project or separable project element under the Louisiana Coastal Area (LCA) may

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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.

2.2 PUBLIC CONCERNS

Public input was received through coordination with the sponsor, coordination with

other agencies, public review of draft and interim products, and through workshops,

and public meetings. A National Environmental Policy Act (NEPA) scoping meeting

was held on Thursday, February 12, 2009 in French Settlement, Louisiana in which

LCA plan, the NEPA process and milestones, an overview of the study goals and

objectives, and maps of the study area were presented. Overall, the public has

expressed its general approval and support for the LCA ARDC Modification project.

A discussion of public involvement is included in Section 6, Public Involvement,

Review and Consultation. The public concerns were considered and incorporated

into the establishment of planning objectives, planning constraints and

management measures listed below:

• Weir at French Settlement does not function properly and diverts excessive

flow to ARDC, impairing lower Amite River.

• Project should incorporate weir construction at downstream end of ARDC.

• ARDC construction has disrupted natural hydrologic regime and damaged

properties.

• Endangered/protected species are present in the study area and vicinity.

• Scope of project should address wildlife and fisheries habitat.

• Hydraulics and Hydrology (H&H) modeling should be expansive, incorporate

conditions from other projects, and/or involve stage data collection.

• Project should incorporate rehabilitation of weir at French Settlement.

• Southwestern boundary of study area should be expanded.

• Boat trips to reconnaissance study area are needed.

• Diversion canal stages are primarily influenced by Lake Maurepas.

• Gap placement is an issue because of development on dredge material berms.

• Swamps south of Bayou Pierre are impaired from acidity caused by lack of

hydrologic exchange.

• Project is greatly needed and should be completed on an expedited schedule.

• Project should include vegetative planting and nutria control.

• Create hydrologic exchange between Bayou Pierre and ARDC on south canal

bank.

• Colonial nesting waterbird rookeries are present in the study area.

• Draining swamp waters may impair water quality in ARDC and downstream.

• Project should operate under flood events, not merely normal flow or high

flow conditions.

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• Dredge material berm gapping has been implemented as part of waterfront

development projects in study area.

• Avoidance or minimization of forest habitat impacts should be considered

during gap location.

• Project scope should include restoration of lower Amite River.

The Integrated Feasibility Report and Supplemental Environmental Impact Study

(FS/SEIS) was released to the public on May 21, 2010, and was followed by a 45-day

public review period ending on July 6, 2010. A public meeting was held on June 24,

2010 in French Settlement Louisiana. Comments received and the responses to

them are included in Appendix G.

2.3 PROBLEMS, NEEDS, AND OPPORTUNITIES

This study is designed to address ecosystem restoration problems and opportunities

in the LCA ARDC 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 LCA:

• Coast 2050

• Louisiana Coastal Area (LCA) Report

• Louisiana Coastal Protection and Restoration (LACPR) Technical Report

• Integrated Ecosystem Restoration and Hurricane Protection: Louisiana’s

Comprehensive Master Plan for a Sustainable Coast

Planning for this project uses data from these reports and additional public scoping.

Alternative plans will be formulated to build upon these previous plans.

2.3.1 2004 LCA Ecosystem Restoration Report

The 2004 LCA Ecosystem Restoration report summarizes the problems, needs, and

opportunities facing coastal Louisiana.

The problems, needs, and opportunities, specific to the LCA ARDC study area, were

determined based upon the 2004 LCA report, as well as prior comprehensive

planning studies, public input, and inter-agency information exchange. Systemwide problems and opportunities were used to identify and define more

geographically specific problems and opportunities throughout the LCA ARDC

study area (Table 2.1) (see Section 1.5). 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. A Conceptual

Ecological Model (CEM) was also developed to further identify specific study area

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Table 2.1. Problems and Opportunities by LCA ARDC Study Area Subunits

Problem Degree of Problem by Subunit NW-1 NW-2 NE-1 NE-2 NE-3 SW-1 SW-2 SE-1 SE-2

Subsidence Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate ModerateSea level Rise Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate ModerateTropical Cyclone Events Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate

Modification of NaturalHydrology:

Impoundment Minimal Minimal Severe Severe Minimal Minimal Minimal Moderate ModerateDecreased Freshwater,Sediment, and Nutrient Inputs Minimal Minimal Moderate Severe Minimal Minimal Moderate Severe SevereHabitat Changes and Land Loss:Decreased Productivity Minimal Minimal Moderate Severe Severe Minimal Moderate Severe SevereIncreased Seedling Mortality Minimal Minimal Minimal Severe Severe Minimal Moderate Severe SevereIncreased Habitat Conversion Minimal Minimal Moderate Severe Severe Minimal Moderate Severe SevereInvasive Species Minimal Minimal Moderate Moderate Moderate Moderate Moderate Moderate Moderate

Opportunity Subunit NW-1 NW-2 NE-1 NE-2 NE-3 SW-1 SW-2 SE-1 SE-2

Improve hydrologic processesimpaired by dredged materialbank construction, includingconnectivity, sheet flow, andfreshwater nutrient inflow andoutflow.

X X X X

Prevent future cypress swampdegradation and transitioncurrently predicted to occur.

X X X X

Improve areas that have beendegraded and transitioned tofresh or open water.

X X X X

Protect vital socioeconomic andpublic resources. X X X X

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problems. The project-specific problems and opportunities are located in

Sections 2.3.3 and 2.3.6, respectively, of the report.

2.3.2 Conceptual Ecological Model

The CEM developed for the LCA ARDC Modification project, identifies specific

study area problems via diagrammatic relationships between major anthropogenic

and natural stressors, biological indicators, and target ecosystem conditions

(Appendix I). The LCA ARDC CEM:

(1) Identifies drivers of ecological processes, anthropogenic stressors, and

their ecological effects and attributes useful in monitoring and

forecasting ecosystem response;

(2) Diagrams qualitative explanations of how human activities alter ecology;

(3) Develops and communicates working hypotheses;

(4) Identifies performance measures; and

(5) Develops monitoring and modeling activities to support restoration and

management.

This CEM does not explain all possible relationships or include all possible factors

influencing the performance measure targets within natural systems in the study

area. Rather, the CEM model displays ecosystem functioning relationships within

the study area by presenting only the information deemed most relevant to

ecosystem monitoring goals.

The CEM developed for the LCA ARDC Modification project is presented in

Figure 2.1. Model components are identified as the following:

• Drivers

 Canal Construction

 Hurricanes

• Ecological Stressors

 Impoundment

 Lack of Riverine Input and Connectivity

 Storm Surge

• Ecological Effects

 Trees Stressed and Die

 Increased Seedling Mortality

 Loss of Nutrients and Sediments

 Decreased Water Quality and Increased Salinity

 Decreased Productivity

 Increased Habitat Conversion

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Figure 2.1. Conceptual Ecological Model, Amite River Diversion Canal Modification Project

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 Increased Subsidence

• Attributes and Performance Measures

 Land Cover

 Vegetation Monitoring

 Elevation

 Water Quality

The Wetland Value Assessment (WVA) model was used to evaluate the

environmental benefits of the final array in Section 3. The WVA measures

functional benefits for the Future With Project (FWP) as compared to Future

Without Project (FWOP) (see Section 3.5.2). While the CEM does not directly

provide quantitative data for the WVA, the CEM provides the ecological principles

that are quantitatively captured by the WVA.

2.3.3 Problems

According to the 2004 LCA Ecosystem Restoration Study, the measurable increase

in coastal land loss in the mid- to late- 20th century can be linked to human

activities that have fundamentally altered the deltaic processes of the coast and

limited their ability to rebuild and sustain it. In the Chenier Plain, human activities

have fundamentally altered the hydrology of the area, which has impacted the longterm sustainability of the coastal ecosystems. Because of the magnitude and variety

of these human-induced changes, and their interaction with natural landscape

processes, all of the factors contributing to coastal land loss and ecosystem

degradation must be viewed together to fully understand how Louisiana's coastal

ecosystem shifted from the historical condition of net land gain to the current

condition of accelerated net land loss.

According to the 2004 LCA report, the natural processes of subsidence, habitat

switching, and erosion of wetlands, combined with a widespread human alteration,

have caused significant adverse impacts to the Louisiana coastal area, including

increased rates of wetland loss and ecosystem degradation. Without action,

Louisiana’s healthy and highly productive coastal ecosystem, composed of diverse

habitats and wildlife, is not sustainable. Man-made alterations have impacted the

natural sustainability and quality of the Louisiana coastal ecosystem. This loss of

sustainability has manifested itself as accelerated land loss. If recent loss rates

continue into the future, even taking into account current restoration efforts,

coastal Louisiana is projected to lose an additional 328,000 acres of coastal marshes,

swamps, and barrier islands by the year 2050. The loss of wetlands could result in

ecosystem conversion to open water by placing the following ecosystem functions at

risk:

• Vegetative habitat suitability and community diversity;

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• Elevational maintenance and soil contribution from decomposing organic

material;

• Protection against substrate erosion;

• Water quality improvement;

• Nutrient uptake and carbon sequestration;

• Important nursery habitat;

• North American Central Flyway and North American Mississippi Flyway

waterfowl;

• Wintering habitat; and

• Resting and feeding areas for neotropical migrants.

LCA ARDC Study Area. The primary problem within the LCA ARDC study

area is ecosystem degradation of the freshwater swamps adjacent to the ARDC. The

natural hydrology within the study area has been modified by construction of the

ARDC (1964) and construction of the railroad grade utilized during the 1800s

through the early 1900s to aid with lumber extraction activities (see Figure 1.3 with

location of railroad grade). These features have resulted in impoundment of the

swamp. Sea level rise (Gornitz et al., 1982) and geological subsidence have

compounded the effects of these modifications. The modification of the hydrology

within the study area has led to hydrologic isolation; impoundment of water,

including storm surge-related, higher salinity waters; and lack of freshwater,

sediment and nutrient inputs, all of which have contributed to the degradation and

conversion of the freshwater swamps to marsh and open water habitats.

Impoundment leads to a reduction in freshwater, sediment and nutrient input

within the study area.

2.3.3.1 Modification of Natural Hydrology

The construction of flood control projects within the LCA ARDC study area,

primarily the ARDC component of the Amite River and Tributaries (AR&T) project,

together with other land use practices, such as land development and logging, have

significantly altered the hydrology of the study area. These projects and practices

have altered patterns of water and sediment flow through the bald cypress-tupelo

swamp, directly converting swamps to marsh and open water and indirectly

altering the natural processes instrumental in the development and sustenance of a

healthy coastal swamp ecosystem.

2.3.3.2 Subsidence

Land elevations decrease from subsidence, which may be produced by

compaction, oxidation, and consolidation of sediments, faulting, groundwater

depletion, or decreased organic deposition as a result of decreased vegetation

biomass production. Within a healthy freshwater swamp, land elevations have the

potential to increase as a result of sediment accretion, from direct sediment input

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from riverine sources or from organic vegetation deposition. The soil characteristics

of the western Maurepas Swamp indicate a lack of riverine influence as evidenced

by high soil organic matter content and low bulk density values (DeLaune et al.,

1979; Hatton, 1981; Messina and Conner, 1998). Consequently, soil building within

the Maurepas Swamp is almost exclusively a result of organic productivity (Shaffer

et al., 2001, 2003, 2006 and 2009). In the swamps adjacent to the ARDC,

productivity is substantially depressed compared to normal conditions (Coastal

Wetlands Planning, Protection and Restoration Act (CWPPRA) Task Force, 2002).

Subsidence in the LCA ARDC study area and vicinity is classified as intermediate,

at about 1.1-2.0 feet per century (LCA, 2004). With minimal soil building and

intermediate subsidence, there has been a net lowering of ground surface elevation,

doubling flood frequency over the last four decades (Thompson, 2000), so that the

swamps are now persistently flooded.

2.3.3.3 Sea Level Rise

2.3.3.3.1 Eustatic Sea Level Rise. Eustatic sea level rise is the

global change in the oceanic water level. Eustatic sea level rise has been attributed

to the global increase in ocean volume and has been estimated as 1.0-2.4

millimeters per year (mm/yr) (Church et al., 2001). Long-term sea level rises are

projected to increase due to global climate change (Titus and Richman, 2001).

2.3.3.3.2 Relative Sea Level Rise. Relative sea level rise refers to

the difference between the change in eustatic sea level and the change in land

elevation. The combination of subsidence and eustatic sea level rise would likely

cause the landward movement of marine conditions into estuaries, coastal wetlands

and fringing uplands (Day and Templet, 1989). Relative sea level rise has been

measured in the Mississippi Delta at rates as high as 10 mm/yr (Snedden et al.,

2007).

Based on guidance in USACE EC-1165-2-211, it was determined that

a low estimate for relative sea level rise over for the 50-year period of analysis

(2061) is 1.5 ft (0.46 m); an intermediate estimate is 1.9 ft (0.58 m); and a high

estimate is 3.2 ft (0.97 m). Sediment and organic accretion will not likely mitigate

RSLR, especially with no action. Under the FWOP condition little to no biomass

accretion would occur due to the continued degradation within the study area and

the lack of hydrologic connectivity. It has been estimated that biomass accretion

levels for a healthy freshwater swamp within the study area would be

approximately 8 mm/yr (Bernard Wood, unpublished data, 2005 through 2009).

2.3.3.4 Tropical Cyclone Events

Tropical cyclone events exert a stochastic but severe influence on the LCA

ARDC study area. Tropical cyclone events can directly and indirectly contribute to

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coastal land loss through a variety of processes, including erosion from increased

wave energies, removal and/or scouring of vegetation from storm surges, and

saltwater intrusion into estuaries and interior wetlands carried by storm surges.

These destructive processes can result in the loss and degradation of large areas of

coastal habitats in a relatively short period of time (e.g., days and weeks versus

years). These saltwater surges become impounded for long periods of time in the

areas of impact along the ARDC, causing additional damage to the soils and

vegetation.

The storm centers of at least 15 tropical cyclones with a Saffir-Simpson

Hurricane Scale of Category 2 or higher have passed within 50 miles of the LCA

ARDC study area during the interval 1851-2008, and at least 52 such tropical

cyclones have passed within 100 miles of the study area during the same interval

(National Oceanic and Atmospheric Association (NOAA) Coastal Services Center,

2009). The most recent tropical cyclones affecting the study area were hurricanes

Katrina (August 2005), Rita (September 2005) and Gustav and Ike (September

2008).

Hurricanes Katrina, Rita, Gustav, and Ike – These tropical storms did

not have a significant direct impact on the study area; there was very little wind

and wave damage as noted by subsequent field investigations. These, and other

storms, did have an indirect effect due to the introduction of higher-salinity storm

surge waters into the impounded swamps within the LCA ARDC study area. This

salt intrusion, particularly in the impounded areas, reduces biomass production and

impairs health, which in turn increases tree mortality, decreases soil production

and integrity, and consequently increases relative subsidence (CWPPRA Task

Force, 2002). These higher-salinity storm surge waters become impounded in the

swamp by the dredged material berms along the ARDC and are not drained from

the swamps during seasonal low flow events or flushed by seasonal river bank

overflow events. Consequently, these periodic influxes of saline storm surge waters

cumulatively increase salinity in impounded waters and soils in the study area.

Even though salinity spikes are inevitable, increased connectivity through the

ARDC dredged material berms would allow the large headwater event that

normally follows a tropical storm to flush the higher salinity waters out of the

swamp before it has an opportunity to infiltrate into the substrate. This flushing

action could greatly reduce the impact of salinity spike generated by tropical storm

events.

2.3.4 Effects

A direct result of the problems impacting the study area include the impoundment

of water within the swamp areas, reduced amounts of natural hydrologic

connectivity which leads to limited amounts of sediment and nutrient transport to

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the swamp habitat, and the eventual degradation of existing habitat. The following

section describes each of these effects.

2.3.4.1 Impoundment

The placement of dredged material as berms along either side of the ARDC

disrupted sheet flow within the LCA ARDC study area and formed topographic high

points (ridges) that prevented the drainage of bald cypress-tupelo swamps into the

ARDC during low surface flow intervals (USACE, 2004). This activity, in

conjunction with other activities, such as the construction of a railroad grade

utilized for logging that traverses the eastern study area from north to south,

permanently impounded bald cypress-tupelo swamp habitat within the study area.

Impoundment within the study area has also contributed to decreased water

quality and increased cypress and tupelo seedling mortality, which in turn have

contributed to increased habitat conversion to marsh and open water. Additional

damages to vegetative resources and soils have occurred when saltwater storm

surges are impounded within the system over long periods; vegetation becomes

stressed and additional salt leaches into the soil substrate. Increased connectivity

through the ARDC dredged material berms would decrease impoundment and allow

a large headwater event to flush the higher salinity waters out of the swamp before

it has an opportunity to infiltrate into the substrate. This flushing action could

greatly reduce the impact of salinity spike generated by tropical storm events.

Swamp impoundment is particularly pronounced in the eastern portion of the

LCA ARDC study area (subunits NE-1 and NE-2), as demonstrated by 2005

hydrograph data from the CWPPRA Priority Project List (PPL) 16 proposal

Hydrologic Restoration in the Swamps West of Lake Maurepas, Figure 2.2, and

Table 2.2.

Table 2.2. Conversion of Habitat Types (Years to Marsh)

Years to Marsh Acres

Existing Marsh 300

10 Years to Marsh 1,723

20 – 30 Years to Marsh 7,979

30 – 50 Years to Marsh 8,202

Total 18,204

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Image: 2009 Livingston Parish and Ascension Parish USDA-FSA-APFO NAIP MrSID Mosaics

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana Date: February 2010 Scale:

Source: USGS/GEC

HABITAT TYPES

Map ID: 27850108-1890

Little Bayou Chene Blanc

Blind River

New River Canal

Petite Amite River

Chinquapin Canal

Bayou Chene

Amite River Diversion Canal

Railroad

Grade

Railroad

Grade

Old River

Blanc

Amite River

Flat

Lake

Weir

New

River Heath Bayou

NW-1

SW-1

SW-2

NW-2

NE-1 NE-2

SE-2

SE-1

NE-3

Petite Amite R vi

r e

Bayou An

ot

ni e

Bayou Chene Blanc

Bayou Pierre

1:75,000

0 0.5 1 1.5 2

Miles

Legend

Subunits

Habitat Types

Marsh10 Years to Marsh20-30 Years to Marsh30-50 Years to Marsh

SE-1

Mississippi

Arkansas

Texas

Map Extent

Figure: 2.2

Source: Bernard Wood, personal communication, October 2009

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The habitat types shown in Figure 2.2 represent areas of degradation

expected to occur within the study area over the 50-year period of analysis, based on

field observations and professional judgment provided by Dr. Gary Shaffer. More

specifically, Table 2.2 quantifies acreages associated with each habitat type found in

Figure 2.2. The figure includes four habitat types, consisting of existing marsh, 10-

years to convert to marsh, 20-30 years to convert to marsh, and 30-50 years to

convert to marsh.

Marsh. This represents areas within the study area that have converted to

freshwater marsh habitat and are in transition to open water. These areas are

characterized by non-existent canopy and scrub-shrub and herbaceous type

vegetation. These areas are considered the most degraded within the study area.

10-years to Marsh. This represents areas within the study area likely to

transition into marsh with the next ten years. These areas are characterized by

little-to-no canopy cover, which is indicative of areas in which degradation is taking

place and the habitat is nearing conversion to freshwater marsh. This habitat type

is located in areas with hydrologic connectivity, but lack freshwater flushing and is

subsequently subject to increased saltwater intrusion.

20-30 years to Marsh. This represents areas within the study area likely to

transition into marsh with the next 20-30 years. These areas are characterized by

reduced canopy cover, which is indicative of areas in which freshwater swamp tree

species are present, but exhibit reduced stand productivity. This habitat type

exhibits reduced hydrologic connectivity, is found in impounded areas that lack

freshwater flushing, and is subject to saltwater intrusion during high-water events.

30-50 years to Marsh. This represents areas within the study area likely to

transition into marsh with the next 30-50 years. These areas are characterized by

the beginning stages of canopy cover reduction, and are indicative of areas in which

freshwater swamp tree species are abundant, but exhibit reduced stand

productivity. This habitat type has little-to-no hydrologic connectivity, is found

within impounded areas that lack freshwater flushing, and is often not influenced

by saltwater intrusion.

Approximately 11 months of water gage data were recorded in the eastern

portion of the study area from three water gages within the ARDC and inundated

swamp habitat on the left descending bank. These data indicate the swamp habitat

along the left descending bank of the ARDC in the eastern portion of the study area

is impounded; water levels within this area never receded below 2.2 feet above

mean sea level (msl), although canal water levels receded below that level (Shaffer

et al., 2006). Areas within Figure 2.2, which do not display a time frame for

degradation, indicate that no degradation will occur for these areas within the 50-

year period of analysis.

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2.3.4.2 Decreased Connectivity Resulting In Decreased

Freshwater, Sediment, and Nutrient Inputs into the

Swamps

Historically, hydrologic conditions within the LCA ARDC study area were

influenced by the Amite River in the north and west, by overbank flow from the

Mississippi River in the south, and by tidal influence from Lake Maurepas in the

east (Hamilton and Shaffer, 2001; CWPPRA Task Force, 2002). Periodic flooding of

the Amite and/or Mississippi Rivers inundated bald cypress-tupelo swamps within

the study area. Flooding occurred in and near the study area, with peak water

elevations in the late spring or early summer. As floodwaters receded, surface

waters in the study area were conveyed eastward via sheet flow to Bayou Chene

Blanc or Blind River and, then to Lake Maurepas. Flood control implementation

such as construction of the ARDC, disrupted the natural hydrologic regime within

the LCA ARDC study area. River channelization and levee construction greatly

reduced overbank flooding in the study area, nutrients and sediments in the

ecosystem were lost, and water quality was decreased (CWPPRA Task Force, 2002).

The swamp within the LCA ARDC study area is severely nutrient-limited

(Shaffer et al., 2001). However, biomass production of herbaceous vegetation has

been significantly enhanced (approximately 33 percent) by nutrient augmentation

based on data from monitoring stations located within the western Maurepas

Swamp outside of the study area.

Decreased water quality and increased salinity have also contributed to

swamp ecosystem degradation in the LCA ARDC study area. A water quality

analysis of surface waters in the western Maurepas Swamp was conducted in

support of CWPPRA Project PO-29 Mississippi River Reintroduction into Maurepas

Swamp (Day et al., 2001). Nitrate, ammonium, and nitrogen concentrations at

surface water stations in the western Maurepas Swamp were lower than

Mississippi River concentrations. As a result, the bald cypress-tupelo swamp in the

study area and vicinity is severely nutrient-limited. The trees are also highly

stressed from elevated salinities, which decrease productivity and increase

mortality and susceptibility to herbivory and parasites (CWPPRA Task Force,

2002).

Saltwater intrusion has increased in this general area, partly due to net

subsidence and the lack of riverine freshwater inputs. Salinities as low as three

parts per thousand (ppt) can reduce growth of both bald cypress and water tupelo

saplings (Pezeshki, 1990). Salinity, combined with flooding stress, can substantially

reduce bald cypress growth. Consequently, salinity significantly contributes to

swamp deterioration, particularly combined with stressors such as flooding and

herbivory.

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Storm surges from Lake Maurepas caused by tropical cyclones also exert a

stochastic but severe stress on the swamp habitat through salinity spikes in swamp

surface waters. Dredged material berms prevent higher salinity water from being

flushed out of the system (CWPPRA Task Force, 2002). Storm surge waters remain

in the impounded swamps of the LCA ARDC study area cumulatively increasing

salinities in impounded waters and soils.

2.3.4.3 Habitat Changes and Land Loss

Decreased Productivity. Vegetative communities in the LCA ARDC

study area have decreased productivity according to previous reports and studies

(Hoeppner et al., 2007). The existing levels of productivity in the western Maurepas

Swamp are as low as 25 to 50 percent of average values found within swamps that

are managed or have more favorable hydrology, and/or receive nutrient enrichment

(Hamilton and Shaffer, 2001).

From 2000-2007, diameter growth measurements for more than 1,800

trees in the western Maurepas Swamp were significantly less than established

growth levels for trees in healthy freshwater swamp systems (Shaffer et al., 2008).

In interior swamp locations, such as the LCA ARDC study area, the primary factors

inhibiting diameter growth were nutrient-poor stagnant standing water and the

lack of nutrient-rich freshwater exchange caused by the loss of hydrologic

connectivity with riverine systems.

Increased Seedling Mortality. Seedling germination and

establishment are essential to ensure sustainability of bald cypress-tupelo swamp

by replacing trees lost to disease and other causes. However, the establishment of

bald cypress and tupelo seedlings is impaired in the LCA ARDC study area due to

persistent flooding from impoundment (CWPPRA Task Force, 2002). Bald cypress

and tupelo seeds cannot germinate when flooded (Hamilton and Shaffer, 2001).

Seeds of both species remain viable when submerged in water and can germinate

readily when floodwaters recede (Kozlowski, 1984). However, the seedlings require

seasonal drying periods, and the substrate compaction associated with these drying

periods, for root systems to become properly established in the swamp substrate.

With minimal ability to drain and persistent flooding, the typical seasonal drying of

the LCA ARDC swamp does not usually occur and seedlings fail to establish

themselves and replace older trees lost to other natural processes (CWPPRA Task

Force, 2002).

Nutria, which are common to the study area, pose a threat to seedling

establishment, and could result in increased mortality of planted and regenerated

freshwater swamp vegetation.

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Increased Habitat Conversion. As shown in Section 5.6.2 most of

the Maurepas Swamp is stressed and appears to be on a trajectory of slow

degradation leading to a gradual conversion to marsh and open water (Hoeppner

et al., 2007). Stagnant flooding and nutrient deprivation appear to be the largest

stressors in the swamp interior, whereas increased salinity, flooding stress, and

nutrient deprivation are killing many trees along the navigable waterways, such as

the ARDC and Blind River.

Under the continued influence of these conditions, tree mortality would

continue to increase and tree density would continue to decline. Based on the low

tree density, degraded condition, and expectation for mortality, the USACE

estimated that most swamp habitat within the LCA ARDC study area would

degrade to less than 33 percent canopy cover within 20 years (USACE, 2004).

Approximately 46 percent of the canopy within the study area would remain within

20 to 30 years; this is comparable to USACE data (Figure 2.3) (Shaffer et al., 2009).

Because of this degradation and decreased productivity, soil accretion is insufficient

to offset regional subsidence, and the degraded swamp habitat is consequently

susceptible to conversion to fresh marsh (Hamilton and Shaffer, 2001). Land area

trends in the study area for the interval 1985-2006 were calculated by the U.S.

Geological Survey (USGS) using Landsat Thematic Mapper (TM) analysis (Barras

et al., 2008). Land area trends within the study area were relatively stable with an

average land loss of less than two acres per year. However, Landsat TM imagery

does not distinguish between forested canopy and marsh vegetation. Other studies

indicate that land area trends for bald cypress-tupelo swamp in the study area are

unstable and habitat conversion is occurring at an accelerated rate in portions of

the study area (USGS, 2008).

Bald cypress-tupelo swamp is already converting to freshwater marsh

in the LCA ARDC study area particularly north of the ARDC in the eastern study

area in subunits NE-2 and SE-2 (CWPPRA Task Force, 2002). Many fresh marsh

areas in the greater southern Maurepas Swamp have converted to fragile spikerush

flotant. Approximately 9,702 acres of swamp habitat would fully convert to marsh

habitat within 20 to 30 years (Figure 2.2 and Table 2.2). Throughout this report the

habitat surrounding the ARDC is referred to as freshwater or bald cypress-tupelo

swamp. While it is recognized that portions of the study area have converted to

freshwater marsh, it is generally referred to as a freshwater swamp habitat.

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Figure 2.3. Predicted Land Change for Coastal Louisiana (USACE, 2004)

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Without restoration, factors and processes contributing to stress and

deterioration of swamps near the ARDC would continue and result in swamp

habitat loss with succession to open water. The wetland loss rates developed by

Coast 2050 for the Amite/Blind Rivers mapping unit (which contains the LCA

ARDC study area) for 1974-1990 were estimated to be 0.83 percent per year for

swamp habitat, and 0.02 percent per year for fresh marsh (CWPPRA Task Force,

2002). Based on these rates, approximately 35 percent (18,204 acres) of the bald

cypress-tupelo swamp within the study area would be converted to fresh marsh or

open water for the interval 2012-2062.

2.3.4.4 Increased Invasive Species

The spread of invasive species decreases native plant communities, altering

ecosystem function. Within the LCA ARDC study area, water hyacinth, alligator

weed, hydrilla, common salvinia, giant salvinia, and variable-leaf milfoil are

invasive aquatic vegetative species, which displace native aquatics and degrading

water and habitat quality [Louisiana Coastal Protection and Restoration (LACPR),

2009]. Additionally, the study area has the Chinese tallowtree which is tolerant to

flooding and salt stress and can establish self-replacing monocultures that provide

less foraging value to migrating birds and interrupt the natural succession of woody

species (LACPR, 2009). It should be noted that disturbed ecosystems are more

vulnerable to invasive species than stable ecosystems; therefore, invasive species

are a severe threat to biodiversity and ecological function in the study area. An

additional invasive species found throughout the study area are nutria. This

species of wildlife impacts the vegetative resources by increasing seedling mortality

and reducing natural regeneration.

2.3.5 Needs

According to the 2004 LCA report, critical needs for restoration of coastal Louisiana

include:

Prevent future land loss where predicted to occur: Addressing this

need would create and sustain diverse coastal habitats, sustain wildlife and plant

diversity, and sustain socio-economic resources. Effective measures to reverse

coastal land loss should affect plant communities, in their root zone, in such a way

as to promote healthy growth and reproduction, plant succession, or revegetation of

denuded surfaces. Increasing nutrients and sediment in the estuarine area would

increase the growth of marsh vegetation and slow the rate of land loss. Increased

plant growth would result in greater production of organic detritus that is essential

for a high rate of fisheries and wildlife production. Production of phytoplankton and

zooplankton would increase in areas where turbidity is not limiting, and, as a

result, the harvest of sport and commercial finfish and shellfish that depend on

these microorganisms would increase.

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Restore fundamentally impaired or mimic deltaic processes through

river reintroductions: Addressing this need would reduce habitat deterioration

by increasing nutrients and sediment delivered to the estuarine-marsh areas, which

would increase marsh vegetation sustainability and improve fish and wildlife

production. In addition, restoring riverine influences to coastal wetlands and

creating wetlands would help address the need to reduce the nutrient loading into

the northern gulf and to reduce the hypoxic zone. This need can be met by restoring

or mimicking distributary flows, crevasses, and over-bank flow, as well as

mechanical marsh creation with river sediment, if sustained by freshwater

reintroductions.

Restore or preserve endangered critical geomorphic structures:

Addressing this need would restore geomorphic structures, such as natural levee

ridges, lake rims, land bridges, gulf shoreline barrier islands, barrier headlands,

and chenier ridges. These features are essential to maintaining the integrity of

coastal ecosystems because they are an integral part of the overall system and in

many instances represent the first line of defense against marine influences and

tropical storm events.

Protect vital local, regional, and national socioeconomic resources:

Addressing this need would reduce the increased risk of damage to cultures,

communities, infrastructure, business and industry, and flood protection.

Accelerated land loss and ecosystem degradation places over $100 billion of

infrastructure at increased risk to damage as a result of storm events. This need

could be met by increasing the marsh’s capacity to buffer hurricane-induced

flooding through wetland creation, and sustenance and retention of barrier island

systems.

The critical needs for the LCA ARDC Modification project study area were

developed based on those included in the 2004 LCA report and include the

following:

Prevent future conversion of freshwater swamp habitat to

freshwater marsh and ultimately open water: Addressing this need would help

to reverse the trend of land degradation occurring within the LCA ARDC study area

and contribute to maintaining critical habitat for numerous species of vegetation,

fish, and wildlife species native to freshwater swamp habitats. The habitat

degradation occurring within the study area is previously depicted in Figure 2.2.

Restore the natural processes necessary for a functioning and

healthy freshwater swamp habitat: Addressing this need would preserve and

improve the functions provided by bald cypress-tupelo swamp habitat, vital to

numerous wildlife and vegetative species. Functions would include natural

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hydrologic cycles, hurricane protection, and improved water quality. Restoring these

functions increases the likelihood of producing a sustainable ecosystem.

Preserve and protect local socioeconomic resources: Addressing this

need would prevent the loss of socioeconomic resources available within the LCA

ARDC study area, resulting from continued habitat degradation and land loss. This

includes the reduction in storm surge and hurricane winds provided by a healthy

freshwater swamp, and improved water quality.

2.3.5.1 Future Without Project Condition

Without Federal action, the swamp habitat surrounding the ARDC would

continue to degrade resulting in the eventual conversion from a freshwater swamp

to a freshwater marsh and open water. The FWOP condition would be the

continued impoundment of swamp water within the study area, a reduction in tree

canopy, water quality, hydrologic connectivity, and a transition towards marsh and

salinity-tolerant vegetation. Storm surges from tropical cyclone events would

increase salinity levels, and the frequency of saltwater inundation is expected to

increase with Relative Sea Level Rise (RSLR). The FWOP is the basis to compare

the alternatives in Plan Formulation (Section 3).

It is anticipated that the swamp will continue to convert to fresh marsh and

eventually to open water (Figure 2.2). The lack of exchange of freshwater,

sediments, and nutrients will continue to lead to reduced tree vigor and growth,

increased tree mortality, increased invasive species stands, and loss of ecological

functions. Likely, with the expected RSLR rise, the swamp degradation would

accelerate in the future. Major portions of subunits NE-2, SE-2, and SE-1, would

likely deteriorate to fresh marsh within 30 years (Figure 2.2), some areas have

already converted to fresh marsh. Additionally, the fresh marsh habitat will

convert to open water and additional wetland functions will be lost. The effects of

the FWOP on each resource are presented in Table 5.1.

Functions lost include habitat for wildlife and aquatic species, recreational

opportunities, aesthetics, and storm surge protection. The freshwater marsh does

offer some of the functions of the freshwater swamp, but certain functions are lost,

such as habitat for avian species and some storm surge protection. Based on the

findings of the 2004 LCA report, preserving and protecting freshwater swamp

habitat is of national significance.

Analysis has shown that there has been some recovery for relic open areas in

subunit SW-2. However, these relic open areas were not caused by the ARDC

dredged material banks. All analyses and investigations to date have suggested

that the ARDC dredged material berms have, and likely will continue, to cause

degradation of the fresh water swamp habitat.

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Indirect impacts resulting from the continued habitat degradation would be

the continued decline of wildlife, fishery, and vegetative resources. Flora and fauna

species could experience stress due to saline waters not being flushed from the

system, and may change as salt-tolerant species replace fresh water species. Air

quality would decline due to population growth in Livingston and Ascension

Parishes and increased numbers of vehicles and further commercialization and

industrialization. Existing swamp habitat would convert to water bottoms and

alter the benthic community, and decrease available nutrients and detritus. The

habitat quality would continue to degrade, thereby creating a stressful environment

for species present. Continued degradation would result in loss of habitats for

protected species that utilize the study area, including the West Indian manatee,

and Gulf sturgeon. Degraded viewscapes for the study area would be a result of

degradation. Coastal Louisiana’s wetland loss and the depletion of wetlanddependent natural resources could result in a decline of job opportunities and

personal income throughout rural coastal areas. Existing and future infrastructure

present within the study area would be adversely affected. Maurepas Wildlife

Management Area (WMA), is the only public lands located within a portion of the

study area, would be affected. There would be increased exposure of existing oil,

gas, and utility pipelines to coastal land loss, which would increase operations,

maintenance, repair, replacement, and rehabilitation (OMRR&R) costs, as well as

increase the required investment in facilities and pipelines. Coastal forest habitat

provides protection from tropical cyclone events; consequently, there could be an

increase in storm surge and risk of flooding. Wetland loss would impact

commercially important species, including black drum, brown and white shrimp,

and blue crab, leading to declining abundances.

Cumulative impacts would be shoreline erosion and land loss resulting in a

projected conversion of 18,204 acres of swamp soils to fresh marsh and open water.

There would be decreased flows into and out of the swamp due to dredged material

berms along the ARDC, increased water levels due to coastal wetland loss and

increased runoff due to increased urbanization of the Pontchartrain Basin. The

water and air treatment functions of wetlands would subside. The integrity of

existing cultural, historical, and recreational resources, as well as aesthetics within

the study area would be compromised. Infrastructure, public facilities, and

businesses would be adversely impacted. Property values may decline as wetlands

continue to degrade. Public lands would be adversely affected. Localized storm

surge and storm wave damages are likely to increase. A loss of commercial fishery

habitat is likely. Impacts on all forms of vegetation include continued deterioration,

and loss of vegetation and wetland habitat acreage. Continued nationwide wetland

loss would lead to increased acreage of shallow water bottoms. Benthic populations

and plankton would respond to perturbations with a shift towards saline-oriented

species as land loss and saltwater intrusion continue. Land loss within the study

area would threaten the existence and integrity of cultural and historic resources.

Loss of vegetation would degrade the visually complex environment and reduce

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opportunities for viewing wildlife. The degradation and loss of wetlands would

contribute to increased maintenance costs of infrastructure. Several of the current

residential subdivisions within the study area may expand, creating additional

roads, bridges and associated utilities. As populations continue to migrate to

coastal communities, increasing investment in hurricane and flood control levees,

pump stations, and other flood control facilities are likely to increase.

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

uncertain at this time. This spill could potentially adversely impact USACE water

resources projects and studies within the Louisiana coastal area. Potential impacts

could include factors such as changes to existing or baseline conditions, as well as

changes to future-without and future with project conditions. 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 USACE water

resources development projects/studies. Supplemental planning and environmental

documentation may be required as information becomes available.

2.3.6 Opportunities

The 2004 LCA report listed opportunities for ecosystem restoration for coastal

Louisiana as:

• Freshwater reintroductions and outfall management - Diverting water

from the Mississippi River into hydrologic basins can (1) nourish existing

marshes to increase their productivity and build wetlands in areas of open

water, (2) potentially reduce the extent of the hypoxic zone in the gulf, (3)

help satisfy the need for maintaining salinity gradients that correspond to

the diversity of vegetative habitat, and (4) reintroduce and distribute

sediment and nutrients throughout the ecosystem;

• Barrier island restoration, through placement of sand from offshore

sources or the Mississippi River, could sustain these geomorphic

structures, which would provide additional protection from hurricane

storm surges and protect the ecology of estuarine bays and marshes by

reducing gulf influences, as well as protect Nationally important water

bird nesting areas;

• Hydrologic modification, such as degrading excavated dredged material

banks or reestablishing ridges or natural banks, can help restore salinity

and marsh inundation patterns and provide fishery access in previously

unavailable habitats; and

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• The use of sediment material from dedicated dredging or maintenance

dredging (e.g., beneficial use) to create a marsh platform can create large

amounts of coastal habitat quickly.

The 2004 LCA report emphasizes that many of the above techniques can be applied

in combination to produce synergistic effects while minimizing disruptions to the

surrounding ecology and economy (e.g., dedicated dredging in conjunction with a

small river diversion to increase the sustainability of the created marsh).

Opportunities for the LCA ARDC Modification project have been identified to

improve habitat conditions and address many of the problems identified in the

study area. These opportunities were chosen based on the potential for ecosystem

restoration that exists for portions of the study area and were used as the

foundation of the Plan Formulation process.

Opportunities for ecosystem restoration within the LCA ARDC study area as

described in the 2004 report are to:

• Improve the hydrologic processes impaired by dredged material berm

construction, including connectivity, sheet flow, and freshwater nutrient

inflow and outflow;

• Prevent future bald cypress swamp degradation and transition currently

predicted to occur;

• Improve areas that have been degraded and transitioned to fresh marsh or

open water; and

• Protect vital socioeconomic and public resources.

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

The goal of the LCA ARDC Modification project is to reverse the degradation trend

within the western Maurepas Swamp ecosystem that has been adversely affected by

the construction of the ARDC. The project would provide nutrients and sediment

to facilitate organic deposition in the swamp, improve biological productivity, and

prevent further swamp deterioration. According to the 2004 LCA Ecosystem

Restoration report, the exchange of flow would occur during flood events on the

river and from the runoff of localized rainfall events. The project maximizes the use

of restoration strategies that reintroduce historic flows of river water, nutrients,

and sediment to coastal wetlands, and that maintain the structural integrity of the

coastal ecosystem. Execution of the LCA Plan would make significant progress

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towards achieving and sustaining a 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. Benefits to and effects on existing

infrastructure, including navigation, hurricane protection, flood control, land

transportation works, agricultural lands, and oil and gas production and

distribution facilities were considered in the formulation of coastal restoration

plans.

2.4.2 Objectives

The planning objectives identified in the 2004 LCA report include the following:

Hydrogeomorphic Objectives

1. Establish dynamic salinity gradients that reflect natural cycles of

freshwater availability and marine forcing (fluctuation related to normal

daily and seasonal tidal action or exchange).

2. Increase sediment input from sources outside estuarine basins, and

manage existing sediment resources within estuarine basins, to sustain and

rejuvenate existing wetlands and rebuild marsh substrate.

3. Maintain or establish natural landscape features and hydrologic processes

that are critical to sustainable ecosystem structure and function.

Ecosystem Objectives

1. Sustain productive and diverse fish and wildlife habitats.

2. Reduce nutrient delivery to the Continental shelf by routing Mississippi

River waters through estuarine basins while minimizing potential adverse

effects.

The project would provide nutrients and sediment to facilitate organic deposition in

the swamp, improve biological productivity, and prevent further swamp

deterioration.

The objectives identified in 2004 and further investigation of the problems and

opportunities in the study area led to the establishment of the following planning

objectives. In general, the objectives of the LCA ARDC Modification project are to

introduce freshwater, nutrients and sediments into western Maurepas Swamp to

reverse the current trend of deterioration.

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Specific Project Objectives

1. Increase hydrologic connectivity between the degraded swamp and

bottomland hardwood habitats within the study area and the ARDC by

increasing the exchange of freshwater, sediments, and nutrients over the 50-

year period of analysis.

2. Reduce habitat conversion of swamp to open water within the study area

over the 50-year period of analysis.

3. Facilitate natural hydrologic cycle within the study area over the 50-year

period of analysis by reducing impoundment in degraded swamp and

bottomland hardwood habitats adjacent to the ARDC to improve tree

productivity and seedling germination.

4. Improve fish and wildlife habitat within the study area over the 50-year

period of analysis.

Performance measures and desired outcomes to determine project success in

meeting these project objectives have been developed and are presented within the

Adaptive Management and Monitoring Plan (Appendix I).

2.5 PLANNING CONSTRAINTS

Development and evaluation of restoration alternatives for the proposed project are

constrained by a number of factors. Specific Planning Constraints identified for the

LCA ARDC Modification project include the following:

Flood Control: The ARDC is a component of the AR&T (1956) flood control

channel. Project plans must not significantly decrease the performance and

original intent of the ARDC and the AR&T project.

Designated Scenic Rivers: Blind River, located on the perimeter of the

study area, is a designated Scenic River. Designated Scenic Rivers are

protected by a set of use restrictions including channelization, clearing and

snagging, channel realignment, reservoir construction, and commercial

cutting or harvesting of trees or timber in violation of the Louisiana Scenic

Rivers Act. Such restrictions may affect the type of project features that

could be constructed along the Blind River.

Hydroperiod: Water levels within the ARDC exhibit seasonal high channel

flow and low channel flow intervals. The natural variability of the

hydroperiod necessitates a project design that allows the project to function

as intended under a variety of flow regimes, ensuring that the project both

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introduces nutrients and sediments to the adjacent swamps during high

channel flow events and allows draining of swamps for seedling

establishment during low channel flow events.

Other items that were taken into consideration during plan development and plan

selections include:

Drainage Infrastructure: Existing drainage infrastructure within or

adjacent to the study area, such as culverts and canals, performs the vital

function of conveying excess water out of the area during heavy rainfall or

flood events. Formulating a project design that does not impair the capacity

of the existing drainage system with additional waters would help to ensure

that residential flooding is minimized in the area.

Recreation: Minimize disruption of existing recreational use of the area and

ARDC vessel traffic to the extent practicable.

Existing Development: Existing development along portions of the ARDC

dredge material berms. This existing development will be considered as

implementation of a project in these areas would require the demolition and

replacement of certain residential structures and recreational facilities.

Water Quality: Planning objectives of the proposed project include the

periodic draining of the swamp during low-flow intervals in the channel and

flushing the adjacent habitat during high-flow intervals. Previous studies

have indicated that swamps may release phosphorus sequestered within

their substrates when subjected to a freshwater reintroduction. The

introduction of phosphorus and other constituents into the ARDC and the

potential impacts to downstream water bodies are identified ecosystem

constraints for the proposed action. Development of a project design that

minimizes potential negative impacts to downstream water quality is

recommended.

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3.0 ALTERNATIVES

3.1 PLAN FORMULATION RATIONALE

3.1.1 Plan Rationale

The plan formulation process is iterative, comprehensive and includes a number of

detailed evaluations of potential measures and combinations of restoration

measures, and an iterative refinement process for alternative development. This

section presents a streamlined overview of the plan formulation process for the LCA

ARDC Modification project. Specifically, management measures are presented,

screening criteria are discussed, and initial alternative plans are presented along

with the screening process to obtain the final array of alternatives. The alternative

plans identified through the plan formulation process are then evaluated, based on

study area problems and opportunities, as well as study goals, objectives and

constraints. As specified in ER 1105-2-100, four criteria were considered during

alternative plan evaluation: completeness, effectiveness, efficiency, and

acceptability. These criteria are described in Section 3.1.2 of this report.

Additionally, ecosystem benefits, cost-effectiveness, and environmental impacts

were considered to ensure that the Recommended Plan best meets the project

objectives. This section also describes the Tentatively Selected Plan (TSP) as the

confirmed Recommended Plan and its implementation requirements.

As part of plan formulation, a Value Engineering (VE) study was conducted to

identify potential modifications of restoration measures and plan configurations

that could improve the performance and cost-effectiveness of the preliminary

measures. The results of the VE study for this project were fully considered and

were used to refine the measures and alternatives being considered.

A Value Engineering (VE) Study Report was completed to summarize the events of

the VE workshop conducted May 18-22, 2009 for the U.S. Army Corps of Engineers

(USACE), New Orleans District, by Value Management Strategies, Inc (Appendix

H). The subject of the study was a group of three Louisiana Coastal Area (LCA)

ecological restoration projects of which the Amite River Diversion Canal (ARDC)

Modification project was one.

The three alternatives that were considered for the ARDC Modification project

were:

• Increase the size and number of gaps in the railroad ridge.

• Use railroad ridge as an oak tree habitat.

• Develop an alternative that maximizes the long-term fresh water content

of Lake Maurepas as a potential buffer to a major salt water inflow event.

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The key recommended strategy from the VE study decided upon with regard to the

ARDC Modification project was to increase the size and number of gaps in the

railroad ridge. This was applied to the project alternatives as appropriate and is

included as a part of the Recommended Plan.

3.1.2 Plan 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. These

criteria 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, operations,

maintenance, repair, replacement, and rehabilitation (OMRR&R), 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 would 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, regulation, and public policy. The project should have evidence of

broad-based public support and be acceptable to the non-Federal cost sharing

partner.

3.1.3 Environmental Operating Principles

In 2002, the U.S. Army Corps of Engineers (USACE) formalized a set of

Environmental Operating Principles applicable to decision-making in all programs.

The principles are consistent with National Environmental Policy Act (NEPA); the

Army Strategy for the Environment; other environmental statutes, and the Water

Resource Development Act (WRDA) that govern USACE activities. The

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Environmental Operating Principles inform the plan formulation process and are

integrated into all project management processes. Section 3.7.7 of this report

provides information on the effectiveness of the Recommended Plan in meeting all

Environmental Operating Principles. Alternatives were formulated for this project

consistent with the Environmental Operating Principles.

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,

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.

3.2 MANAGEMENT MEASURES

A management measure is a feature (a structural element that requires

construction or assembly on-site) or an activity (a nonstructural action) that can

either constitute an alternative plan by itself or, alternately, can be combined with

other management measures to form an alternative plan.

3.2.1 Development of Management Measures

Management measures were developed to address planning objectives, study area

problems, and capitalize on study area opportunities. These management measures

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were derived from a variety of sources including prior studies, the NEPA public

scoping process, the VE study, academia, and through the expertise of the

interagency project delivery team (PDT).

The management measures were screened based on project objectives, constraints,

effectiveness, and practicality. A total of 105 management measures were

developed to address study area problems and to capitalize on study area

opportunities.

3.2.2 Description of Management Measures

The management measures developed and evaluated for the ARDC study area can

be grouped into the following categories:

Freshwater Reintroduction Measures

• Bank Openings (BO): Discrete openings at various locations along the ARDC

dredged material berms, the relict railroad grade, and the natural banks of

other study area waterways within the component subunits of the study area

were considered. These measures could contribute to establishing hydrologic

connectivity by allowing seasonal drying, promoting water circulation to

improve water quality, and introducing nutrients and sediment to swamps.

Bank openings could include open cuts, culverts, or bridged gaps. The

locations for these openings would be chosen based on natural topography

within the study area and LIDAR photographs of the study area. The

placement of the dredged material would create bottomland hardwood

habitat as a means of combating the effects of sea level rise within the study

area.

• Berm Degradation (BD): Degradation of the entire ARDC dredged material

berm complex, dredged material berm degradation within the component

subunits of the study area, and degradation of the relict railroad grade were

all considered. These measures could contribute to establishing hydrologic

connectivity, allowing seasonal drying, promoting water circulation to

improve water quality, and introducing nutrients and sediment to swamps.

• Conveyance Channel (CC): Construction of conveyance channels in the

component subunits of the study area to establish a hydrologic interface

between the ARDC and interior swamp locations was considered. These

measures could contribute to establishing hydrologic connectivity, allowing

seasonal drying, promoting water circulation to improve water quality, and

introducing nutrients and sediment to swamps. The placement of the dredged

material to create bottomland hardwood habitat was also considered.

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• Hydraulic Pump (PU): Installation of hydraulic pumps between the ARDC

and interior swamp locations within each subunit was considered. These

measures could contribute to establishing hydrologic connectivity, allowing

seasonal drying, promoting water circulation to improve water quality, and

introducing nutrients and sediment to swamps. Additionally, a ring levee

could be utilized to help offset the effects of relative sea level rise.

• Siphon Installation (SI): Installation of siphons in the component subunits of

the study area to establish hydrologic connectivity between the ARDC and

interior swamp locations was considered. These measures could contribute to

establishing hydrologic connectivity, allowing seasonal drying or promoting

water circulation to improve water quality, and introducing nutrients and

sediment to swamps.

• Weir Construction (WC): Construction of weirs along the ARDC dredged

material berms at various locations within the component subunits of the

study area was considered. These measures could contribute to establishing

some hydrologic connectivity at specific water stages and introducing

nutrients and sediment to swamps.

• Weir Rehabilitation (WR): Rehabilitation of the existing weir at French

Settlement at the confluence of the ARDC and the Amite River was

considered. This measure could reduce the flow down the ARDC, thereby

promoting the draining of the swamp in specific areas where existing cuts are

located and impoundment is reduced.

• Wastewater Reintroduction (WWR): The reintroduction of wastewater from

local industries and campsites was considered as a means of adding nutrients

to the swamp habitat. An increase in nutrients could be provided to the

areas currently impounded and therefore cut off from any nutrient supply.

The nutrients would increase the production of tree species within the

interior swamp.

• Maximize Lake Maurepas Freshwater Content to Act as a Saltwater Buffer

(MLM): Measures were considered which would increase the overall

freshwater content within Lake Maurepas in order to reduce saltwater

intrusion from within this area. A reduction in saltwater intrusion would

result in lower salinity levels within the swamp habitat and could allow for

more production and regeneration of native swamp tree species.

Channel Restoration Measures

• Shoal Removal (SR): Removal of shoals or sediment plugs from the mouths of

Bayou Pierre, the lower Amite River, and the Blind River were considered.

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These measures could contribute to establishing hydrologic connectivity,

allowing seasonal drying, promoting water circulation to improve water

quality, and (in the case of Bayou Pierre) introducing nutrients and sediment

to swamps.

• Clearing and Snagging (CS): Clearing and snagging of natural waterways

was considered at various locations within the component subunits of the

study area. These measures could contribute to establishing hydrologic

connectivity, allowing seasonal drying and promoting water circulation to

improve water quality.

• Channel Dredging (CD): Channel dredging of natural waterways at various

locations within the component subunits of the study area was considered.

These measures could contribute to establishing hydrologic connectivity,

allowing seasonal drying and promoting water circulation to improve water

quality.

Habitat Restoration Measures

• Non-Structural Vegetative Planting (VP): Vegetative planting to restore bald

cypress-tupelo communities in degraded areas throughout the study area was

considered. This measure could contribute to preventing habitat conversion

and future land loss, increasing swamp vegetative productivity, and restoring

and preserving wildlife habitat. Plantings would serve as a means of creating

a seed source in the study area for future regeneration as well. Nutria, which

inhabit the study area, would increase seedling mortality. Nutria guards

would be installed to protect the vegetative plantings.

• Spray Dredging (SD): Spray dredging of degraded areas adjacent to the

ARDC was considered. This measure is a form of marsh creation in which

dredged material is broadcast within a specific area in order to create marsh

habitat. This measure could contribute to preventing habitat conversion and

future land loss and restoring and preserving wildlife habitat. This measure

was also considered a means by which to combat the effects of sea level rise

within the study area.

• Habitat Creation via Placement of Dredged Material (HC): The placement of

dredged material as additional upland and bottomland hardwood habitat was

considered. These areas could serve as refuge for some species of wildlife

during high-water events while also providing areas to implement

supplemental plantings of bottomland hardwood tree species.

• Dedicated Dredging (DD): Dedicated dredging of Lake Maurepas for

beneficial use material in marsh creation was considered. Dedicated dredging

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is a form of marsh creation in which the material is mechanically or

hydraulically placed within a specified area in order to create marsh habitat.

This measure could contribute to preventing habitat conversion and future

land loss and restoring and preserving wildlife habitat. This measure was

also considered a means by which to combat the effects of sea level rise

within the study area.

3.2.3 Screening/Evaluation of Management Measures

All 105 measures were screened based upon many criteria including: project

objectives and constraints, benefits gained, expected subunit degradation,

effectiveness, adverse environmental impacts, and practicability. Measures were

screened out if they did not partially achieve any project objectives or if there were

more effective or efficient measures available. Even though each measure was

evaluated against its ability to accomplish the project objectives, no measure was

eliminated if a specific objective was not achieved. Consideration was given to those

measures which failed to achieve any of the stated objectives, but could be combined

with other measures to achieve the project objectives. The effectiveness of each

measure was considered to ensure that the objectives would be adequately met. If a

measure resulted in overall, negative environmental impacts it was screened out.

The practicability of each measure was considered to ensure that each measure

could be implemented with a feasible amount of effort. From the 105 measures

considered, 14 were retained for further study. Some measures originally

considered, such as the removal of the entire dredged material berm along the

ARDC, were screened out prior to the final development of all 105 management

measures. Conversely, upon further feedback from the PDT, some measures were

introduced after the initial group of measures was developed, such as the clearing

and snagging of existing channels and bayous. Through this iterative process, the

final 105 management measures were developed.

The screening strategy also included the evaluation of the study areas hydrologic

subunits (Table 3.1) to determine subunits with the most near-term degradation, in

keeping with the overall LCA goals to first address near-term degradation. The

resultant subunits and management measures were further evaluated based on

aerial photography, additional information, and field investigations. Of the nine

subunits, four were retained for further study and evaluation.

Aerial photography indicated the general health or historical decline of some of the

subunits within the study area. Most degradation could be linked with

impoundment or a lack of hydrologic connectivity. However, for subunit SW-2

breaks in the canopy were identified in some of the earlier photographs, before

construction of the ARDC. In order to account for these openings, additional

analysis of the aerial photographs was conducted as stated in Table 3.1.

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Table 3.1. Evaluation of Hydrologic Subunits

Hydrologic

Subunit Description Reason Eliminated

NW-1

This subunit is connected hydrologically by Bayou Pierreand the Amite River. This area also contains an extensivehousing development. Aerial photography and fieldinvestigation indicated that there was little degradationand thus little to no opportunity for restoration.

Eliminated because hydrologic connectivity with BayouPierre and Amite River already exist within this area. Norestorative actions are warranted, therefore this subunitwas eliminated

NW-2

This subunit contains the healthiest portion of thewestern Maurepas Swamp. Aerial photography and fieldinvestigation indicated that there was little opportunityfor restoration.

This subunit provides a comparison for other degraded areasdue to its healthy state. No restorative actions arewarranted, therefore this subunit was eliminated.

NE-1 This subunit is in need of restoration and there is an opportunity for restoration. This subunit was found to be a degraded area, therefore this subunit was retained.NE-2

This subunit has a high degree of habitatdegradation and there is an opportunity forrestoration.

This subunit was found to be a highly degraded area,therefore this subunit was retained.

NE-3

This subunit has a degree of habitat change; however, nohydrologic measures were identified that would benefitthe area. Aerial photography and field investigation

indicated that there was little opportunity for restoration.

Due to a lack of impoundment, no hydrologic or restorativemeasures were identified that would benefit the area.Therefore this subunit was eliminated.

SW-1

This subunit is in good health and contains a series ofculverts that provide hydrologic connectivity between theswamp and the ARDC. Aerial photography and fieldinvestigation indicated that there was little opportunityfor restoration.

Due to existing hydrologic connectivity between the swampand ARDC there are no measures that could benefit thissubunit. Therefore this subunit was eliminated.

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Hydrologic

Subunit Description Reason Eliminated

SW-2

This subunit does not appear to need restoration. Initialreview of aerial photographs suggested that degradationmay be occurring due to the presence of some open waterareas. However, a more detailed review of historic aerialphotographs dating to 1940, before the construction of theARDC, indicated that these openings historically existed(Figures 3.1-3.3). The aerial review indicated that the

canopy in these open areas are developing a more closedcanopy, suggesting recovery is already underway.Louisiana Department of Wildlife and Fisheries personnelrecommended not dredging the bayous off the PetiteAmite River on the WMA to drain ponds because standingwater is beneficial to wildlife during droughts. Duringdroughts, these open areas provide refugia for manyaquatic and semi-aquatic species as well as drinkingwater for terrestrial wildlife. The open areas appear to bea natural feature of the landscape and not a humaninduced phenomenon, and does not need restoration.

Based on a review of historic aerial photography, noapparent habitat degradation has occurred in this subunitdue to construction of the ARDC. Therefore, no restorativeactions are warranted and the subunit was eliminated.

SE-1

This subunit has degraded areas, although not asdegraded as NE-1 and NE-2. There areopportunities to restore and reduce degradation byincreasing freshwater, sediment, and nutrientexchange.

There are opportunities to restore and improve thissubunit by increasing connectivity to the ARDC,therefore it was retained.

SE-2

This subunit has degradation associated withstagnation and saltwater intrusion. There areopportunities to increase connectivity with theARDC to increase connectivity and flush highersalinity waters after tropical storm events.Although the swamps of SE-2 are hydrologically

connected to Blind River, this area needs freshwater, nutrients, and sediments, including theflushing of high saltwater intrusion events.

Sediment, water, and nutrient connectivity andinflow from the ARDC would benefit this area,including the flushing of saltwater intrusion aftertropical storm events. While connectivity with Blind

River does exist within the southern portions of thissubunit, overall hydrologic connectivity between theARDC and the northern portions of this subunitwould provide additional nutrients and flushsaltwater intrusion introduced by high-water events

via Blind River. Therefore, this subunit was retained.

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As part of an initial screening process, the nine hydrologic subunits (NW-1, NW-2,

NE-1, NE-2, NE-3, SW-1, SW-2, SE-1, SE-2) were examined to determine the degree

of degradation, level of existing hydrologic connectivity, and identification of

hydrologic measures that would benefit the area, and subunits NE-1, NE-2, SE-1

and SE-2 were retained for further study (Table 3.1). The most near-term

degradation is expected to occur in the easternmost subunits and the opportunity to

restore habitat is the greatest in these four subunits. Although there is some

degradation in NE-3, it is not caused by the ARDC or other man-made sources.

There does not appear to be an opportunity for restoration in NE-3. The

westernmost subunits, NW-1 and SW-1 appear to be healthy and no restoration is

needed. NW-2 is overall a very healthy system, mainly due to the connectivity with

the Petite Amite River. SW-2 is a mostly healthy system with some areas expected

to become marsh within 20-30 years. Public comments initially indicated that

degradation had occurred within subunit SW-2. However, based on analysis of

aerial photography and discussions with the Louisiana Department of Wildlife and

Fisheries, it was determined that any perceived degradation existed within the

subunit before construction of the ARDC (Figures 3.1 through 3.3). This analysis

also showed that portions of SW-2 improved from 1940 to 2005. Therefore, it was

concluded that subunit SW-2 was not degraded due to the construction of the ARDC

or any problems stipulated in Section 2.3 of this report.

As a result of the initial screening process, several of the hydrologic subunits were

determined to be healthy freshwater swamp habitat, with little to no habitat

degradation. This emphasized a lack of near-term ecosystem restoration

opportunities for these areas and deemphasized a need for immediate restoration

action. However, this does not imply that other restoration actions would not be

warranted, but that any other restoration effort would be beyond the scope of this

project. The long-term preservation of these areas through acquisition by the state

of Louisiana or a private land trust would help to maintain healthy habitat within

these areas.

After evaluating each hydrologic subunit, the measures were screened based on

project objectives, constraints, effectiveness, impacts, and practicability (Table 3.2).

The measures carried forward for further evaluation were assembled into

alternative plans designed to address study goals and objectives. All management

measures considered were deemed consistent with Administration budget policy,

specific USACE policies for ecosystem restoration, and Federal laws, regulations,

and Executive Orders.

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Figure 3.1. 1940 Aerial Photography with Area of Impact Outlined

Figure 3.2. 1940 Aerial Photography -- Close-Up of Area of Interest

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Figure 3.3. 2005 Color Infrared Photography -- Area of Interest

3.2.4 Management Measures Not Carried Forward

for Further Analysis

Of the 105 original measures developed, 91 measures (Table 3.2) were eliminated

from further consideration due to screening of the hydrologic subunits, failure to

partially meet project objectives, or the measure was deemed impracticable or

ineffective due to project constraints. Fourteen measures were retained for further

study (Table 3.2). Vegetative planting, a non-structural measure, was retained in

conjunction with other measures; not as a standalone measure, because it was

determined that plantings would not provide benefits without restored hydrologic

connectivity. Some measures, such as dedicated dredging with ring levees, were

considered as mitigation of RSLR. However, further investigation suggested that

impacts would be great and benefits would be low; these measures were eliminated.

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Table 3.2. Management Measures Considered with Screening Results

Management

Measure Description Screening Results

BD-01 Degradation of the entire ARDC dredged material berm

Eliminated due to a lack of practicality. Removal of large portions or all of the dredgedmaterial berms is not necessary to achieve any of the project objectives. Bank openings areviewed as a more feasible measure. Implementation of this measure would also destroyexisting upland habitat found within the study area.

BO-01 Opening at confluence of Bayou Pierre and ARDC at LA-22, SW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, the Petite Amite does provide adequatehydrologic connectivity. Analysis also revealed that canopy loss within SW-2 existed beforethe ARDC was constructed. Therefore, no opportunity for restoration exists and the measurewas eliminated.

BO-02

Opening at confluence of BayouPierre and ARDC south of LA-22,SW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, the Petite Amite does provide adequatehydrologic connectivity. Analysis also revealed that canopy loss within SW-2 existed beforethe ARDC was constructed. Therefore, no opportunity for restoration exists and the measurewas eliminated.

BO-03

Openings along ARDC throughoutstudy area, at intersections ofrelict channels

Eliminated as a standalone measure, but other BO and CC measures would be located in thelow areas of relic channels as much as practicable.

BO-04 Openings on lower Amite River, NW-1 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project.BO-05 Openings on lower Amite River, NW-2 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project.BO-06 Openings on south bank Bayou Chene Blanc, NE-1 Eliminated because additional field investigation determined adequate hydrologic connectivity already exists in these areas; and habitat would have little to no improvement with these measures.BO-07 Openings on south bank Bayou Chene Blanc, NE-2 Eliminated because additional field investigation determined adequate hydrologic connectivity already exists in these areas; and habitat would have little to no improvement with these measures.BO-08 Openings on west bank Blind River, NE-2 Eliminated because additional field investigation determined adequate hydrologic connectivity already exists in these areas; and habitat would have little to no improvement with these measures.BO-09 Openings on west bank Blind River, SE-1 Eliminated because additional field investigation determined adequate hydrologic connectivity already exists in these areas; and habitat would have little to no improvement with these measures.

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Management

Measure Description Screening Result

BO-10 Openings on west bank Blind River, SE-2 Eliminated because additional field investigation determined adequate hydrologic connectivity already exists in these areas, and habitat would have little to no improvement with these measures.BO-11 Openings on east bank of Petite Amite River, NE-1 Eliminated because additional field investigation determined adequate hydrologic connectivity already exists in these areas, and habitat would have little to no improvement with these measures.BO-12 Openings on east bank of Petite Amite River, SE-1 Eliminated because additional field investigation determined adequate hydrologic connectivity already exists in these areas, and habitat would have little to no improvement with these measures.BO-13 Openings on north bank ARDC, NE-1 Eliminated because it would be problematic to develop a bank opening through an existing subdivision, due to utility relocations; hydrologic connectivity could be achieved for the easternmost portion of NE-1 (the only portion that is degraded) via a connection through NE-2.

BO-14 Openings on north bank ARDC, NE-2 Retained (Meets Objective 2, Objective 3 and Objective 4). Would provide connectivity for freshwater, nutrients, and sediments when combined with a bank opening.BO-15 Openings on south bank ARDC, SE-2 Retained (Meets Objective 2, Objective 3 and Objective 4). Would provide connectivity for freshwater, nutrients, and sediments when combined with a bank opening.BO-16 Openings on south bank ARDC, SE-1 Retained (Meets Objective 2, Objective 3 and Objective 4). Would provide connectivity for freshwater, nutrients, and sediments when combined with a bank opening.

BO-17 Openings on south bank ARDC, SW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, the Petite Amite does provide adequate hydrologicconnectivity. Analysis also revealed that canopy loss within SW-2 existed before the ARDC wasconstructed. Therefore, no opportunity for restoration exists and the measure was eliminated.

BO-18 Openings on south bank ARDC, SW-1 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project.BO-19 Openings on north bank ARDC, NW-1 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project.

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Management

Measure Description Screening Result

BO-20 Openings on north bank ARDC, NW-2 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project.BO-21 Openings on west bank of Petite Amite River, SW-2

Historic aerial photograph analysis and field investigations indicated that while some minor degradationexists within portions of SW-2, the Petite Amite does provide adequate hydrologic connectivity. Analysisalso revealed that canopy loss within SW-2 existed before the ARDC was constructed. Therefore, noopportunity for restoration exists and the measure was eliminated.

BO-22 Openings on west bank of Petite Amite River, NW-2 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project.

BO-23 Openings on railroad grade, NE-1/NE-2 Retained (Meets Objective 2, Objective 3 and Objective 4). Would provide connectivity for freshwater, nutrients, and sediments when combined with a bank opening.BO-24 Openings on railroad grade, SE-1/SE-2 Retained (Meets Objective 2, Objective 3 and Objective 4). Would provide connectivity for freshwater, nutrients, and sediments when combined with a bank opening.

CC-01 Conveyance channel, NE-1/NE-2 Retained (Meets Objective 1, Objective 2, Objective 3 and Objective 4)

CC-02 Conveyance channel, NW- 1/NW-2 Eliminated because hydrologic connectivity already exists within both subunits and little to no habitat restoration would occur. Conveyance channels were retained as a design feature and combined with bank openings. This combination was retained for further study.

CC-03 Conveyance channel, SE-1/SE-2 Retained (Meets Objective 1, Objective 2 and Objective 4). Would provide connectivity for freshwater, nutrients, and sediments when combined with a bank opening.

CC-04 Conveyance channel, SW- 1/SW-2

Historic aerial photograph analysis and field investigations indicate that little to no degradation exists inthe areas near the convergence of SW-1 and SW-2. Adequate hydrologic connectivity already exists withinboth subunits. Therefore, no opportunities exist for restoration. Conveyance channels were retained as a

design feature and combined with bank openings. This combination was retained for further study, whilethe stand-alone measure was eliminated.

CD-01 Channel dredging, Bayou Chene Blanc, NE-1/NE-2 Eliminated because further field investigations determined that surface water connections in this portion of these areas are adequate. Furthermore, it was determined that the bayou has already reached a natural equilibrium and would therefore silt back in within a few years of over-excavating.

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Measure Description Screening Result

CD-02 Channel dredging, Bayou Pierre, NW-1/NW-2, SW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, adequate hydrologic connectivity exists. Analysis alsorevealed that canopy loss within SW-2 existed before the ARDC was constructed. Therefore, noopportunity for restoration exists and the measure was eliminated. Furthermore, it was determined thatthe bayou has already reached a natural equilibrium and would therefore silt back in within a few yearsof over-excavating.

CD-03 Channel dredging, Blind River, NE-2/SE-1/SE-2

Eliminated because further field investigations indicated that these areas are hydrologically connectedwith Blind River and therefore, no restoration opportunities exist. Furthermore, it was determined thatthe bayou has already reached a natural equilibrium and would therefore silt back in within a few yearsof over-excavating.

CD-04 Channel dredging, Lower Amite River, NW-1/NW-2

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and therefore did not meet the objectives of the project. Furthermore, itwas determined that the river has already reached a natural equilibrium and would therefore silt backin within a few years of over-excavating.

CD-05 Channel dredging, Petite Amite River, NW-2/NE-1

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and that hydrologic connectivity already exists for this portion of thestudy area. Furthermore, it was determined that the river has already reached a natural equilibriumand would therefore silt back in within a few years of over-excavating.

CD-06 Channel dredging, Petite Amite River, SW-2/SE-1

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and that hydrologic connectivity already exists for this portion of thestudy area. Furthermore, it was determined that the river has already reached a natural equilibriumand would therefore silt back in within a few years of over-excavating.

CS-01

Clearing and snagging ofBayou Chene Blanc, NE1/NW-2

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and that hydrologic connectivity already exists for this portion of thestudy area. Furthermore, clearing and snagging is not needed and would result in no added flow thoughthe bayou.

CS-02 Clearing and snagging of Bayou Pierre, SW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, adequate hydrologic connectivity exists. Analysis alsorevealed that canopy loss within SW-2 existed before the ARDC was constructed. Therefore, noopportunity for restoration exists and the measure was eliminated.

CS-03 Clearing and snagging of Bayou Pierre, NW-1 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project. Furthermore, clearing and snagging is not needed and would result in no added flow though the bayou.

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Measure Description Screening Result

CS-04 Clearing and snagging of Bayou Pierre, NW-2 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project. Furthermore, clearing and snagging is not needed and would result in no added flow though the bayou.CS-05 Clearing and snagging of Blind River, NE-2/SE-2 Eliminated because further field investigations determined that surface water connections in this area are adequate. Furthermore, clearing and snagging is not needed and would result in no added flow though the river.CS-06

Clearing and snagging oflower Amite River, NW1/NW-2

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and therefore did not meet the objectives of the project. Furthermore,clearing and snagging is not needed and would result in no added flow though the river.

CS-07

Clearing and snagging ofPetite Amite River, NW2/NE-1

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and therefore did not meet the objectives of the project. Furthermore,clearing and snagging is not needed and would result in no added flow though the river.

CS-08

Clearing and snagging ofPetite Amite River, SW2/SE-1

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, adequate hydrologic connectivity exists. Analysis alsorevealed that canopy loss within SW-2 existed before the ARDC was constructed. Therefore, noopportunity for restoration exists and the measure was eliminated.

DD-01

Dedicated dredging ofborrow areas andplacement within ringlevees to combat subsidenceand sea level rise withinthe study area

Eliminated because these measures would result in a substantial habitat loss, placement of thismaterial would be difficult, and the ecosystem benefits would be limited.

HC-01

Placement of dredgedmaterial from theconstruction ofconveyance channels as

additional upland andbottomland hardwoodhabitat in NE-1/NE-2

Retained (Meets Objective 4)

HC-02

Placement of dredgedmaterial from theconstruction of conveyancechannels as additionalupland and bottomlandhardwood habitat in NW1/NW-2

Eliminated because hydrologic connectivity already exists within both subunits and little to no habitat

restoration would occur, therefore conveyance channels were eliminated as a management measurewithin these subunits.

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Measure Description Screening Result

HC-03

Placement of dredgedmaterial from theconstruction ofconveyance channels asadditional upland andbottomland hardwoodhabitat in SE-1/SE-2

Retained (Meets Objective 4)

HC-04

Placement of dredgedmaterial from theconstruction of conveyancechannels as additionalupland and bottomlandhardwood habitat in SW1/SW-2

Eliminated because hydrologic connectivity already exists within both subunits and little to no habitatrestoration would occur, therefore conveyance channels were eliminated as a management measurewithin these subunits.

MLM-01

Increasing the overallfreshwater content withinLake Maurepas in order toreduce saltwater intrusionfrom within this area.

Eliminated because the reduction of salinity levels through the introduction of freshwater from other

rivers or lakes is beyond the scope of this project. This issue will be addressed by other projects outsidethe study area.

MPDT-1 Removing the entire railroad grade Eliminated because much of the existing railroad grade is characterized as bottomland hardwood habitat and complete removal of the railroad grade would destroy this important and valuable habitat.MPDT-2

Dredging the entirerailroad grade to use asconveyance

Eliminated because implementation would destroy existing bottomland hardwood wildlife habitat. Inaddition, the railroad grade is not located in an area that would effectively drain the swamp.Conveyance channels would provide a more effectively drain of the swamp.

MPDT-3

Constructing openings inthe banks of Blind River atNE-3.

Eliminated because no impoundment exists within NE-3, therefore bank openings would provide noadditional hydrologic connectivity or benefits.

MPDT-4 Dredging Bayou Chene Blanc Eliminated because no dredging is needed. It was determined that the bayou has already reached a natural equilibrium and would therefore silt back in within a few years of over-excavating.MPDT-5

Clearing and snaggingBayou Chene Blanc andLittle Bayou Chene Blanc

Eliminated because clearing and snagging is not needed and would result in no added flow though thebayou.

MPDT-6 NE-2 dredging the pullboat channel Retained (Meets Objective 1, Objective 2 and Objective 4)

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Measure Description Screening Result

MPDT-7

Introducing secondarytreated wastewater intoSW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, adequate hydrologic connectivity exists. Analysis alsorevealed that canopy loss within SW-2 existed before the ARDC was constructed. Therefore, noopportunity for restoration exists and the measure was eliminated.

MPDT-8

Use dredged ARDCopening material tocreate additional habitat

Retained (Meets Objective 4)

PU-01 Hydraulic Pumps, NE-1

Eliminated because the OMRR&R and size of pumps required to improve the swamp habitat areimpracticable and would have reduced reliability as well as lost restoration opportunities when thepumps fail.

PU-02 Hydraulic Pumps, NE-2

Eliminated because the OMRR&R and size of pumps required to improve the swamp habitat areimpracticable and would have reduced reliability as well as lost restoration opportunities when thepumps fail.

PU-03 Hydraulic Pumps, NW-1

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and therefore did not meet the objectives of the project. Additionally, theOMRR&R and size of the pumps required to improve the swamp habitat are impracticable and wouldhave reduced reliability as well as lost restoration opportunities when the pumps fail.

PU-04 Hydraulic Pumps, NW-2

Eliminated because further field investigations and historic aerial photograph analysis indicated thatthese areas were not degraded and therefore did not meet the objectives of the project. Additionally, theOMRR&R and size of the pumps required to improve the swamp habitat are impracticable and wouldhave reduced reliability as well as lost restoration opportunities when the pumps fail.

PU-05 Hydraulic Pumps, SE-1

Eliminated because the OMRR&R and size of pumps required to improve the swamp habitat areimpracticable and would have reduced reliability as well as lost restoration opportunities when thepumps fail.

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Measure Description Screening Result

PU-06 Hydraulic Pumps, SE-2

Eliminated because the OMRR&R and size of pumps required to improve the swamp habitat areimpracticable and would have reduced reliability as well as lost restoration opportunities whenthe pumps fail.

PU-07 Hydraulic Pumps, SW-1

Eliminated because further field investigations and historic aerial photograph analysis indicatedthat these areas were not degraded and therefore did not meet the objectives of the project.Additionally, the OMRR&R and size of the pumps required to improve the swamp habitat areimpracticable and would have reduced reliability as well as lost restoration opportunities whenthe pumps fail.

PU-08 Hydraulic Pumps, SW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, adequate hydrologic connectivity exists. Analysisalso revealed that canopy loss within SW-2 existed before the ARDC was constructed. Therefore,no opportunity for restoration exists and the measure was eliminated. Additionally, theOMRR&R and size of the pumps required to improve the swamp habitat are impracticable andwould have reduced reliability as well as lost restoration opportunities when the pumps fail.

PU-09 Hydraulic Pumps with a Ring- Levee, SE-1/SE-2, NE-1/NE-2 Eliminated because the OMRR&R and size of pumps required to improve the swamp habitat are impracticable and would have reduced reliability as well as lost restoration opportunities when the pumps fail.

RG-01 Removal of entire railroad grade, NE-1/NE-2 Eliminated because much of the existing railroad grade is characterized as bottomland hardwood habitat and complete removal of the railroad grade would destroy this important and valuable habitat.RG-02 Removal of entire railroad grade, SE-1/SE-2 Eliminated because much of the existing railroad grade is characterized as bottomland hardwood habitat and complete removal of the railroad grade would destroy this important and valuable habitat.

RS-01 Removal of entire ARDC north dredged material berm, NE-1 Eliminated because complete removal is not needed to achieve adequate connectivity into the adjacent swamp habitat and removal would lead to a large loss of bottomland hardwood habitat.

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Measure Description Screening Result

RS-02 Removal of entire ARDC north dredged material berm, NE-2 Eliminated because complete removal is not needed to achieve adequate connectivity into the adjacent swamp habitat and removal would lead to a large loss of bottomland hardwood habitat.RS-03 Removal of entire ARDC north dredged material berm, NW-1 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project. Furthermore, removal would lead to a large loss of bottomland hardwood habitat.RS-04 Removal of entire ARDC north dredged material berm, NW-2 Eliminated because further field investigations and historic aerial photograph analysis indicated that these areas were not degraded and therefore did not meet the objectives of the project. Furthermore, removal would lead to a large loss of bottomland hardwood habitat.RS-05

Removal of entire ARDCsouth dredged material berm,SE-1

Eliminated because complete removal is not needed to achieve adequate connectivity across therailroad grade and removal would lead to a large loss of bottomland hardwood habitat.

RS-06

Removal of entire ARDCsouth dredged material berm,SE-2

Eliminated because complete removal is not needed to achieve adequate connectivity across therailroad grade and removal would lead to a large loss of bottomland hardwood habitat.

RS-07

Removal of entire ARDCsouth dredged material berm,SW-1

Eliminated because further field investigations and historic aerial photograph analysis indicatedthat these areas were not degraded and therefore did not meet the objectives of the project.Furthermore, removal would lead to a large loss of bottomland hardwood habitat.

RS-08

Removal of entire ARDCsouth dredged material berm,SW-2

Historic aerial photograph analysis and field investigations indicated that while some minordegradation exists within portions of SW-2, adequate hydrologic connectivity exists. Analysis alsorevealed that canopy loss within SW-2 existed before the ARDC was constructed. Therefore, no

opportunity for restoration exists and the measure was eliminated. Furthermore, removal would

lead to a large loss of bottomland hardwood habitat.

RS-09

Removal of both ARDCdredged material berms,entire lengths

Eliminated because further field investigations and historic aerial photograph analysis indicatedthat these areas were not degraded and therefore did not meet the objectives of the project.Furthermore, removal would lead to a large loss of bottomland hardwood habitat.

SD-01

Spray dredging and ringlevees for degraded areaswithin study area

Eliminated because these measures would result in a substantial habitat loss, placement of thismaterial would be difficult and the ecosystem benefits would be limited.

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Measure Description Screening Result

SI-01 Siphons, NE-1

Eliminated because the OMRR&R, and size and volume of siphons required to improve theswamp habitat is impracticable and would have reduced reliability. Additionally, since little headdifferential is present, it would be very difficult for siphons to function to move enough volume offresh water to improve the habitat.

SI-02 Siphons, NE-2

Eliminated because the OMRR&R, and size and volume of siphons required to improve theswamp habitat is impracticable and would have reduced reliability. Additionally, since little headdifferential is present, it would be very difficult for siphons to function to move enough volume offresh water to improve the habitat.

SI-03 Siphons, NW-1

Eliminated because the proposed area of implementation is not considered degraded and therewould be no habitat improvement with these measures. Additionally, since little head differentialis present, it would be very difficult for siphons to function to move enough volume of fresh waterto improve the habitat. Furthermore, field investigations and historic aerial photograph analysisindicated that these areas were not degraded and therefore did not meet the objectives of theproject.

SI-04 Siphons, NW-2

Eliminated because the proposed area of implementation is not considered degraded and therewould be no habitat improvement with these measures. Additionally, since little head differentialis present, it would be very difficult for siphons to function to move enough volume of fresh waterto improve the habitat. Furthermore, field investigations and historic aerial photograph analysisindicated that these areas were not degraded and therefore did not meet the objectives of theproject.

SI-05 Siphons, SE-1

Eliminated because the OMRR&R, and size and volume of siphons required to improve theswamp habitat is impracticable and would have reduced reliability. Additionally, since little headdifferential is present, it would be very difficult for siphons to function to move enough volume offresh water to improve the habitat.

SI-06 Siphons, SE-2

Eliminated because the OMRR&R, and size and volume of siphons required to improve theswamp habitat is impracticable and would have reduced reliability. Additionally, since little headdifferential is present, it would be very difficult for siphons to function to move enough volume offresh water to improve the habitat.

SI-07 Siphons, SW-1

Eliminated because the proposed area of implementation is not considered degraded and therewould be no habitat improvement with these measures. Additionally, since little head differentialis present, it would be very difficult for siphons to function to move enough volume of fresh waterto improve the habitat. Furthermore, field investigations and historic aerial photograph analysisindicated that these areas were not degraded and therefore did not meet the objectives of theproject.

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Measure Description Screening Result

SI-08 Siphons, SW-2

Eliminated because the proposed area of implementation only exhibits minor degradation andthere would be no habitat improvement with these measures. Additionally, since little headdifferential is present, it would be very difficult for siphons to function to move enough volume offresh water to improve the habitat. Furthermore, field investigations and historic aerialphotograph analysis indicated that these areas were not degraded and therefore did not meet theobjectives of the project.

SR-01 Shoal removal, mouth of Amite River (outside study area) Eliminated because removal of these shoals would have no hydraulic effect on the ARDC in the degraded areas. Field investigations determined that water exchange in this area is adequate and these measures would not affect water surfaces controlled by Lake Maurepas.SR-02 Sediment plug removal, mouth of Bayou Pierre, east of LA 22, SW-2

Eliminated because further field investigations and historic aerial photograph analysis indicatedthat these areas have no opportunity for restoration. Furthermore, it was determined that thebayou has already reached a natural equilibrium and would therefore silt back in within a fewyears of over-excavating.

SR-03 Shoal removal, mouth of Blind River (outside study area) Eliminated because removal of these shoals would have no hydraulic effect on the ARDC in the degraded areas. Field investigations determined that water exchange in this area is adequate and these measures would not affect water surfaces controlled by Lake Maurepas.

VE-01 Increase the size and number of gaps in the railroad ridge

Numerous natural cuts in the railroad grade already exist within degraded areas. Cuts in therailroad grade provide some connectivity in specific areas and help facilitate sheet flow whencombined with other alternatives, but these cuts alone would not provide the hydrologicconnectivity needed to restore the degraded areas within the swamp.

VE-02 Use the railroad ridge as an oak tree habitat Further field investigation determined that a quality bottomland hardwood habitat already exists on the railroad grade and there would be little to no habitat improvements to plant additional

trees.

VE-03

Maximize long-term fresh watercontent of Lake Maurepas as apotential buffer to a majorsaltwater inflow event

Eliminated because it does not meet the project objectives for the LCA ARDC Modification project

and is beyond the scope of the authorized action.

VE-04 Use dredged railroad material to create additional habitat Retained (Meets Objective 4)

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Measure Description Screening Result

VP-01

Vegetative planting, suchas (including bald cypressand tupelo seedlings), indegraded areas

Retained (Meets Objective 4)

VP-02

Vegetative planting, suchas (including water oak andsweetgum seedlings), onmaterial placed fromexcavation of the dredgedmaterial berms.

Retained (Meets Objective 4)

WC-01 Construction of weir on north ARDC bank, NE-1

Eliminated because these structures would impede flow and connectivity. Weirs also could leadto semi-impounding situations, which would actually harm, rather than restore habitat. Moreopen structures are needed to create connectivity and maximize the freshwater, nutrient, andsediment input.

WC-02 Construction of weir on north ARDC bank, NE-2

Eliminated because these structures would impede flow and connectivity. Weirs also could leadto semi-impounding situations, which would actually harm, rather than restore habitat. Moreopen structures are needed to create connectivity and maximize the freshwater, nutrient, andsediment input.

WC-03 Construction of weir on north ARDC bank, NW-1

Eliminated because further field investigations and historic aerial photograph analysisindicated that these areas were not degraded and therefore did not meet the objectives of the

project. Furthermore, these structures would impede flow and connectivity. Weirs also couldlead to semi-impounding situations, which would actually harm, rather than restore habitat.More open structures are needed to create connectivity and maximize the freshwater, nutrient,

and sediment input.

WC-04 Construction of weir on north ARDC bank, NW-2

Eliminated because further field investigations and historic aerial photograph analysisindicated that these areas have no opportunity for restoration. Furthermore, these structureswould impede flow and connectivity. Weirs also could lead to semi-impounding situations,which would actually harm, rather than restore habitat. More open structures are needed tocreate connectivity and maximize the freshwater, nutrient, and sediment input.

WC-05 Construction of weir on south ARDC bank, SE-1

Eliminated because these structures would impede flow and connectivity. Weirs also could leadto semi-impounding situations, which would actually harm, rather than restore habitat. Moreopen structures are needed to create connectivity and maximize the freshwater, nutrient, andsediment input.

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Measure Description Screening Result

WC-06 Construction of weir on south ARDC bank, SE-2

Eliminated because these structures would impede flow and connectivity. Weirs also couldlead to semi-impounding situations, which would actually harm, rather than restore habitat.More open structures are needed to create connectivity and maximize the freshwater,nutrient, and sediment input.

WC-07 Construction of weir on south ARDC bank, SW-1

Eliminated because further field investigations and historic aerial photograph analysisindicated that these areas were not degraded and therefore did not meet the objectives of the

project. Furthermore, these structures would impede flow and connectivity. Weirs also couldlead to semi-impounding situations, which would actually harm, rather than restore habitat.More open structures are needed to create connectivity and maximize the freshwater,

nutrient, and sediment input.

WC-08 Construction of weir on south ARDC bank, SW-2

Eliminated because further field investigations and historic aerial photograph analysisindicated that these no opportunity for restoration exists for this subunit. Furthermore, thesestructures would impede flow and connectivity. Weirs also could lead to semi-impoundingsituations, which would actually harm, rather than restore habitat. More open structures areneeded to create connectivity and maximize the freshwater, nutrient, and sediment input.

WR-01 Rehabilitation of existing weir at French Settlement, NW-1/SW-1 Eliminated because Lake Maurepas water levels control the water levels in the ARDC near the degraded areas. Therefore, changes to this existing weir would have little effect on restoring the degraded habitat. In addition, this weir is outside the LCA ARDC study area.

WWR-01

Reintroduction of wastewaterfrom local industries andcampsites

Eliminated because implementation this measure would result in environmental damagesthat outweigh any benefits. Additionally, the most highly-degraded portions of the study areaare located the furthest from potential wastewater sources.

BO = Bank Openings; BD= Berm Degradation; CC = Conveyance Channels; CD = Channel Dredging; CS = Clearing and Snagging; DD = DedicatedDredging; HC=Habitat Creation; MLM= Maximize Lake Maurepas Freshwater Content to act as a buffer; MPDT = Measures from Project Delivery Team;PU = Pumps; RG = Railroad Grade; RS = Removal of Dredged Material Berm; SD = Spray Dredging; SI = Siphons; SR = Shoal Removal; VE = ValueEngineering; VP = Vegetative Planting; WC = Weir Construction; WR = Weir Rehabilitation; WRR= Wastewater Reintroduction;

Note: Bolded measures were retained for further consideration.

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3.3 PRELIMINARY ALTERNATIVE PLANS

The plan formulation process includes development of a reasonable range of

alternative plans to address the specific problems, needs, and objectives of the study

described in Section 2. Alternative plans are combinations of management

measures. The 14 restoration measures retained for further consideration were

combined and developed into a preliminary array of 45 alternatives that collectively

met study goals and objectives and were within the defined study constraints. All

alternatives developed and the reasons for eliminating particular alternatives are

listed in Table 3.3.

Table 3.3. Description and Screening Results of Alternatives,

Including the Final Array

Alternative Description Screening Result

1

One or more openings in the north bank of the

ARDC in NE-2; dredged material berm

vegetative plantings (BO-14, MPDT-8, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

2

One or more openings in the north bank of the

ARDC in NE-2; dredged material berm and

swamp floor vegetative plantings (BO-14,

MPDT-8, VP-01, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

3

One or more openings in the north bank of the

ARDC in NE-2; dredging bayous leading from

Blind River into NE-2; dredged material berm

vegetative plantings (BO-14, MPDT-8, VP-02,

MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years.

4

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2 and dredged material berm and swamp

floor vegetative plantings (BO-14, MPDT-8,

VP-01, VP-02, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

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Alternative Description Screening Result

5

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; dredged material

berm vegetative plantings (BO-14, MPDT-8,

VP-02, BO-23,VE-04)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore, dredging the

bayous would not be effective or sustainable.

6

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; dredged material

berm and swamp floor vegetative plantings

(BO-14, MPDT-8, BO-23, VE-04, VP-01, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore, dredging the

bayous would not be effective or sustainable.

7

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

NE-1/NE-2; dredged material berm vegetative

plantings (BO-14, MPDT-8, VP-02, BO-23, VE04, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

8

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

NE-1/NE-2; dredged material berm and swamp

floor vegetative plantings (BO14, MPDT-8, BO23, VE-04, VP-01, VP-02, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

9

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in SE-1/SE-2; dredged material

berm vegetative plantings (BO-14, MPDT-8,

VP-02, BO-24, VE-04)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

10

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in SE-1/SE-2; dredged material

berm and swamp floor vegetative plantings

(BO-14, MPDT-8, BO-24, VE-04, VP-01, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

119
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-28 October 2010

Alternative Description Screening Result

11

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

SE-1/SE-2; dredged material berm vegetative

plantings (BO-14, MPDT-8, VP-02, BO-24, VE04, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, the bayous are

not effective or sustainable. Therefore,

dredging the bayous would not be effective or

sustainable.

12

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

SE-1/SE-2; dredged material berm and swamp

floor vegetative plantings (BO-14, MPDT-8,

BO-24, VE-04, VP-01, VP-02, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

13

One or more openings in the north bank of the

ARDC in NE-2; one or more openings in the

south bank of the ARDC in SE-1; dredged

material berm vegetative plantings (BO-14,

MPDT-8, VP-02, BO-16)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

14

One or more openings in the north bank of the

ARDC in NE-2; one or more openings in the

south bank of the ARDC in SE-1; dredged

material berm and swamp floor vegetative

plantings (BO-14, MPDT-8, BO-16, VP-01, VP02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

15

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more openings in the south bank

of the ARDC in SE-1; dredged material berm

vegetative plantings (BO-14, MPDT-8, VP-02,

BO-16, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

120
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-29 October 2010

Alternative Description Screening Result

16

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more openings in the south bank

of the ARDC in SE-1; dredged material berm

and swamp floor vegetative plantings (BO-14,

MPDT-8, BO-16, VP-01, VP-02, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years.

17

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in SE-1/SE-2; one or more

openings in the south bank of the ARDC in SE1; dredged material berm vegetative plantings

(BO-14, MPDT-8, VP-02, BO-24, VE-04, BO-16)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

18

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in SE-1/SE-2; one or more

openings in the south bank of the ARDC in SE1; dredged material berm and swamp floor

vegetative plantings (BO-14, MPDT-8, BO-24,

VE-04, BO-16, VP-01, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

19

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

SE-1/SE-2; one or more openings in the south

bank of the ARDC in SE-1; dredged material

berm vegetative plantings (BO-14, MPDT-8,

VP-02, BO-24, VE-04, BO-16, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

20

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

SE-1/SE-2; one or more openings in the south

bank of the ARDC in SE-1; dredged material

berm and swamp floor vegetative plantings

(BO-14, MPDT-8, BO-24, VE-04, BO-16, VP-01,

VP-02, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

121
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-30 October 2010

Alternative Description Screening Result

21

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more gaps

in the railroad grade in SE-1/SE-2; dredged

material berm vegetative plantings (BO-14,

MPDT-8, VP-02, BO-23, VE-04, BO-24)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, this alternative would result in

limited benefits by only cutting gaps into the

railroad grade in SE-1/SE-2 without also

improving hydraulic connectivity with the

ARDC through proposed conveyance channels.

22

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more gaps

in the railroad grade in SE-1/SE-2; dredged

material berm and swamp floor vegetative

plantings (BO-14, MPDT-8, BO-23, VE-04, BO24, VP-01, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, this alternative would result in

limited benefits by only cutting gaps into the

railroad grade in SE-1/SE-2 without also

improving hydraulic connectivity with the

ARDC through proposed conveyance channels.

23

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more gaps

in the railroad grade in SE-1/SE-2; dredging

pullboat traces/bayous leading from Blind

River into NE-2; dredged material berm

vegetative plantings (BO-14, MPDT-8, VP-02,

BO-23, BO-24, VE-04, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, this alternative would result in

limited benefits by only cutting gaps into the

railroad grade in SE-1/SE-2 without also

improving hydraulic connectivity with the

ARDC through proposed conveyance channels.

Dredging would benefit only a limited area as

well. It was determined that the bayous have

already reached a natural equilibrium and

would therefore silt back in within a few

years. Therefore, dredging the bayous would

not be effective or sustainable.

24

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more gaps

in the railroad grade in SE-1/SE-2; dredging

pullboat traces/bayous leading from Blind

River into NE-2; dredged material berm and

swamp floor vegetative plantings (BO-14,

MPDT-8, BO-23, BO-24, VE-04, VP-01, VP-02,

MPDT-6)

This alternative was eliminated because it

was determined that added conveyance

channels into the swamp, was necessary to

achieve hydrological connectivity and would

result in greater benefits. Furthermore, this

alternative would result in limited benefits by

only cutting gaps into the railroad grade in

SE-1/SE-2 without also improving hydraulic

connectivity with the ARDC through proposed

conveyance channels. Dredging would benefit

only a limited area as well. It was determined

that the bayous have already reached a

natural equilibrium and would therefore silt

back in within a few years. Therefore,

dredging the bayous would not be effective or

sustainable.

122
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-31 October 2010

Alternative Description Screening Result

25

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more

openings in the south bank of the ARDC in SE1; dredged material berm vegetative plantings

(BO-14, MPDT-8, VP-02, BO-23, VE-04, BO-16)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

26

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more

openings in the south bank of the ARDC in SE1; dredged material berm and swamp floor

vegetative plantings (BO-14, MPDT-8, BO-23,

VE-04, BO-16, VP-01, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

27

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more gaps

in the railroad grade in SE-1/SE-2; openings in

the south bank of the ARDC in SE-1; dredged

material berm vegetative plantings (BO-14,

MPDT-8, VP-02, BO-23, VE-04, BO-24, BO-16)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

28

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more gaps

in the railroad grade in SE-1/SE-2; openings in

the south bank of the ARDC in SE-1; dredged

material berm and swamp floor vegetative

plantings (BO-14, MPDT-8, BO-23, BO-24, VE04, BO-16, VP-01, VP-02)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

29

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

NE-1/NE-2; one or more openings in the south

bank of the ARDC in SE-1; dredged material

berm vegetative plantings (BO-14, MPDT-8,

VP-02, BO-23, VE-04, BO-16, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

30

One or more openings in the north bank of the

ARDC in NE-2; dredging pullboat

traces/bayous leading from Blind River into

NE-2; one or more gaps in the railroad grade in

NE-1/NE-2; one or more openings in the south

bank of the ARDC in SE-1; dredged material

berm and swamp floor vegetative plantings

(BO-14, MPDT-8, BO-23, VE-04, BO-16, VP-01,

VP-02, MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

31

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more in

the railroad grade in SE-1/SE-2; dredging

pullboat traces/bayous leading from Blind

River into NE-2; one or more openings in the

south bank of the ARDC in SE-1; dredged

material berm vegetative plantings (BO-14,

MPDT-8, VP-02, BO-23, BO-24, VE-04, BO-16,

MPDT-6)

This alternative was eliminated because it

was determined that just bank openings

would not be effective without conveyance

channels to provide hydrological connectivity

into the swamp. Therefore bank openings

were eliminated as a stand-alone measure.

Furthermore, dredging would benefit only a

limited area. It was determined that the

bayous have already reached a natural

equilibrium and would therefore silt back in

within a few years. Therefore, dredging the

bayous would not be effective or sustainable.

123
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-32 October 2010

Alternative Description Screening Result

32

One or more openings in the north bank of the

ARDC in NE-2; one or more gaps in the

railroad grade in NE-1/NE-2; one or more gaps

in the railroad grade in SE-1/SE-2; dredging

pullboat traces/bayous leading from Blind

River into NE-2, one or more openings in the

south bank of the ARDC in SE-1; dredged

material berm and swamp floor vegetative

plantings (BO-14, MPDT-8, BO-23, VE-04, BO24, BO-16, VP-01, VP-02, MPDT-6)

This alternative was eliminated because it

was determined that added conveyance

channels into the swamp, was necessary to

achieve hydrological connectivity and would

result in greater benefits. Furthermore,

dredging would benefit only a limited area. It

was determined that the bayous have already

reached a natural equilibrium and would

therefore silt back in within a few years.

Therefore, dredging the bayous would not be

effective or sustainable.

33

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; one cut in the railroad

grade located approximately 0.9 miles north of

the ARDC in NE-1/NE-2; dredged material

berm and swamp floor vegetative plantings

(BO-14, MPDT-8, BO-23, VE-04, CC-01, VP-01,

VP-02, HC-01).

Retained as a final alternative. This

alternative would provide the

connectivity for freshwater, nutrients,

and sediments. Additionally, the

alternative would meet all project

objectives.

34

One opening in the south bank of the ARDC in

SE-1 west of and within close proximity to the

railroad grade that extends east and through

the railroad grade between SE-1/SE-2 into SE2; bifurcated conveyance channels; sidecasting

of dredged material; two cuts in the railroad

grade located 0.9 and 2 miles south of the

ARDC in SE-1/SE-2; dredged material berm

and swamp floor vegetative plantings (BO-24,

VE-04, BO-15, BO-16, CC-03, VP-01, VP-02,

HC-03).

Retained as a final alternative. This

alternative would provide the

connectivity for freshwater, nutrients,

and sediments. Additionally, the

alternative would meet all project

objectives.

35

One opening in the south bank of the ARDC in

SE-1; bifurcated conveyance channels;

sidecasting of dredged material; dredged

material berm plantings (BO-16, MPDT-8, VP02, CC-03, HC-03).

Retained as a final alternative. This

alternative would provide the

connectivity for freshwater, nutrients,

and sediments. Additionally, the

alternative would meet all project

objectives.

36

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; one cut in the railroad

grade located approximately 0.9 miles north of

the ARDC in NE-1/NE-2; one opening in the

south bank of the ARDC in SE-1 west of and

within close proximity to the railroad grade

that extends east and through the railroad

grade between SE-1/SE-2 into SE-2; two cuts in

the railroad grade located 0.9 and 2 miles

south of the ARDC in SE-1/SE-2; dredged

material berm and swamp floor vegetative

plantings (BO-14, MPDT-8, BO-23, VE-04, BO24, BO-15, BO-16, CC-01, CC-03, VP-01, VP02, HC-01, HC-03).

Retained as a final alternative. This

alternative would provide the

connectivity for freshwater, nutrients,

and sediments. Additionally, the

alternative would meet all project

objectives.

124
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-33 October 2010

Alternative Description Screening Result

37

Two openings in the south bank of the ARDC

in SE-1; bifurcated conveyance channels;

sidecasting of dredged material; one opening

located just west of the natural ridge that

intersects the south bank of the ARDC and one

west of and within close proximity to the

railroad grade, that extends east and through

the railroad grade between SE-1 and SE-2 into

SE-2; two additional cuts in the railroad grade

located 0.9 and 2 miles south of the ARDC in

SE-1/SE-2; dredged material berm and swamp

floor vegetative plantings (MPDT-8, BO-15,

BO-16, BO-24, VE-04, CC-03, VP-01, VP-02,

HC-03).

Retained as a final alternative. This

alternative would provide the

connectivity for freshwater, nutrients,

and sediments. Additionally, the

alternative would meet all project

objectives.

38

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; one cut located

approximately 0.9 miles north of the ARDC in

NE-1/NE-2; one opening in the south bank of

the ARDC in SE-1; dredged material berm and

swamp floor vegetative plantings (BO-14,

MPDT-8, BO-16, BO-23, VE-04, CC-01, CC-03,

VP-01, VP-02, HC-01, HC-03).

Retained as a final alternative. This

alternative would provide the

connectivity for freshwater, nutrients,

and sediments. Additionally, the

alternative would meet all project

objectives.

39

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; two openings in the south

bank of the ARDC in SE-1, with one cut located

west of and within close proximity to the

railroad grade, that extends east and through

the railroad grade between SE-1/SE-2 into SE2; three cuts in the railroad grade, one cut

located approximately 0.9 miles north of the

ARDC in NE-1/NE-2 and two additional cuts in

the railroad grade located 0.8 and 2 miles

south of the ARDC in SE-1/SE-2; dredged

material berm and swamp floor vegetative

plantings (BO-14, MPDT-8, BO-23, BO-24, VE04, BO-15, BO-16, CC-01, CC-03, VP-01, VP02, HC-01, HC-03).

Retained as a final alternative. This

alternative would provide the

connectivity for freshwater, nutrients,

and sediments. Additionally, the

alternative would meet all project

objectives.

40

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; one cut in the railroad

grade located approximately 0.9 miles north of

the ARDC in NE-1/NE-2; dredged material

berm vegetative plantings (BO-14, MPDT-8,

BO-23, VE-04, CC-01, VP-02, HC-01).

This alternative was eliminated because it

was determined that vegetative plantings,

located within the highly-degraded portions of

the study area, are essential to the near-term

restoration of critical freshwater swamp

habitat. It was determined that natural

regeneration would not occur within these

areas for several decades without the

implementation of vegetative plantings.

125
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-34 October 2010

Alternative Description Screening Result

41

One opening in the south bank of the ARDC in

SE-1 west of and within close proximity to the

railroad grade that extends east and through

the railroad grade between SE-1/SE-2 into SE2; bifurcated conveyance channels; sidecasting

of dredged material; two cuts in the railroad

grade located 0.9 and 2 miles south of the

ARDC in SE-1/SE-2; dredged material berm

vegetative plantings (BO-24, VE-04, BO-15,

BO-16, CC-03, VP-02, HC-03).

This alternative was eliminated because it

was determined that vegetative plantings,

located within the highly-degraded portions of

the study area, are essential to the near-term

restoration of critical freshwater swamp

habitat. It was determined that natural

regeneration would not occur within these

areas for several decades without the

implementation of vegetative plantings.

42

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; one cut in the railroad

grade located approximately 0.9 miles north of

the ARDC in NE-1/NE-2; one opening in the

south bank of the ARDC in SE-1 west of and

within close proximity to the railroad grade

that extends east and through the railroad

grade between SE-1/SE-2 into SE-2; two cuts in

the railroad grade located 0.9 and 2 miles

south of the ARDC in SE-1/SE-2; dredged

material berm vegetative plantings (BO-14,

MPDT-8, BO-23, VE-04, BO-24, BO-15, BO-16,

CC-01, CC-03, VP-02, HC-01, HC-03).

This alternative was eliminated because it

was determined that vegetative plantings,

located within the highly-degraded portions of

the study area, are essential to the near-term

restoration of critical freshwater swamp

habitat. It was determined that natural

regeneration would not occur within these

areas for several decades without the

implementation of vegetative plantings.

43

Two openings in the south bank of the ARDC

in SE-1; bifurcated conveyance channels;

sidecasting of dredged material; one opening

located just west of the natural ridge that

intersects the south bank of the ARDC and one

west of and within close proximity to the

railroad grade, that extends east and through

the railroad grade between SE-1 and SE-2 into

SE-2; two additional cuts in the railroad grade

located 0.9 and 2 miles south of the ARDC in

SE-1/SE-2; dredged material berm vegetative

plantings (MPDT-8, BO-15, BO-16, BO-24, VE04, CC-03, VP-02, HC-03).

This alternative was eliminated because it

was determined that vegetative plantings,

located within the highly-degraded portions of

the study area, are essential to the near-term

restoration of critical freshwater swamp

habitat. It was determined that natural

regeneration would not occur within these

areas for several decades without the

implementation of vegetative plantings.

44

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; one cut located

approximately 0.9 miles north of the ARDC in

NE-1/NE-2; one opening in the south bank of

the ARDC in SE-1; dredged material berm

vegetative plantings (BO-14, MPDT-8, BO-16,

BO-23, VE-04, CC-01, CC-03, VP-02, HC-01,

HC-03).

This alternative was eliminated because it

was determined that vegetative plantings,

located within the highly-degraded portions of

the study area, are essential to the near-term

restoration of critical freshwater swamp

habitat. It was determined that natural

regeneration would not occur within these

areas for several decades without the

implementation of vegetative plantings.

126
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-35 October 2010

Alternative Description Screening Result

45

Three openings in the north bank of the ARDC

in NE-2 with the westernmost cut also

extending through the railroad grade into NE1; bifurcated conveyance channels; sidecasting

of dredged material; two openings in the south

bank of the ARDC in SE-1, with one cut located

west of and within close proximity to the

railroad grade, that extends east and through

the railroad grade between SE-1/SE-2 into SE2; three cuts in the railroad grade, one cut

located approximately 0.9 miles north of the

ARDC in NE-1/NE-2 and two additional cuts in

the railroad grade located 0.8 and 2 miles

south of the ARDC in SE-1/SE-2; dredged

material berm vegetative plantings (BO-14,

MPDT-8, BO-23, BO-24, VE-04, BO-15, BO-16,

CC-01, CC-03, VP-02, HC-01, HC-03).

This alternative was eliminated because it

was determined that vegetative plantings,

located within the highly-degraded portions of

the study area, are essential to the near-term

restoration of critical freshwater swamp

habitat. It was determined that natural

regeneration would not occur within these

areas for several decades without the

implementation of vegetative plantings.

3.3.1 Development of Alternative Plans

The development of alternatives is an iterative process and alternatives were

revised and added throughout the progression of the project. If an alternative was

revised and changed from what was initially considered the alternative received a

new number designation. Through the iterative planning process, a total of 45

alternatives were developed. The final array consisted of seven action

Alternatives 33-39 and the No-Action Alternative. Within the final array,

Alternatives 33, 34, and 35 represent individual Alternatives, while Alternatives 36,

37, 38, and 39 are combinations of the Alternatives 33, 34, and 35.

Vegetative plantings were added to the alternative arrays. Based on research and

additional site investigations, it was determined that the most highly degraded

areas within NE-2 and SE-2 would need to consider vegetative plantings on the

swamp floor (Measure VP-01) as a component proposed within these subunits. (See

Section 3.3.1.1 for further information). Planting of bottomland hardwood species

were also added to alternatives (Measure VP-02) to beneficially use the dredged

material placement resulting from excavation of the conveyance channels, by

creating additional bottomland hardwood habitat.

Conveyance channels were added to the proposed gaps to ensure that a hydraulic

connection between the ARDC and the adjacent swamp was achieved. The need for

these conveyance channels were based on the hydrological and hydraulic analysis,

field reconnaissance, and previous project experience on Davis Pond Freshwater

Diversion project. The conveyance channel dimensions were based on the existing

conveyance channels within the study area and were designed using the width,

depth, and profile of existing sustainable channels. It was determined that if only

gaps were constructed, without conveyance channels, there would not likely be

enough water exchange to keep these gaps open or to improve the swamp habitat.

It was also determined that gaps, with associated conveyance channels, would be

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WRDA 2007 Section 7006(e)(3) 3-36 October 2010

sustainable and allow for adequate water exchange between the ARDC and the

impaired swamp.

3.3.1.1 Inclusion of Vegetative Plantings into Alternatives

Vegetative plantings in highly-degraded freshwater swamp habitats are a

critical component utilized for establishing ecological restoration and obtaining

ecological benefits. The Coastal Wetland Forest Conservation and Use Science

Working Group (CWFCUSWG, 2005) indicated that: “In those areas where flooding

prevents or limits the natural regeneration of the cypress-tupelo forest, artificial

regeneration through tree planting is the only currently viable mechanism to

regenerate the forest. Some swamps are altered to such a significant extent that

even artificial regeneration is not possible.” Once hydraulic connection is restored

within a degraded freshwater swamp, tree vigor and stand productivity will

increase (Shaffer et al. 2009). In areas with an existing canopy, mid-story, and

established regeneration, vegetative plantings would not be necessary. These areas

would have an adequate seed source and stocking levels needed to recover.

However, if an area has degraded to the point that the canopy, mid-story, and

established regeneration is limited or severely stressed, vegetative plantings are

essential to achieve required stocking levels. If a natural seed source is not present

for regeneration to become established, the areas that have already begun

transition to marsh will continue the transition and the severely degraded swamp

areas will not be able to convert back to a functioning swamp habitat. Due to the

highly-degraded conditions found in portions of the LCA ARDC study area (NE-2

and SE-2), natural regeneration would not likely become established within the 50

year period of analysis and would not contribute to the restoration of this NearTerm critical habitat or meet the goals and objectives of the project. Additionally,

vegetative plantings are needed to allow for the establishment of a native tree

community by providing an opportunity for natural succession to occur prior to the

establishment of invasive species, such as the Chinese tallow (Sapium sebiferum).

Reestablishing freshwater swamps through the implementation of vegetative

plantings would generate healthy stand conditions and adequate canopy cover that

will be necessary to establish a swamp prior to the onset of the effects of RSLR to the

study area (Section 3.5.2). Over time, the effects of RSLR would continue to reach a

point in which regeneration of native species is inhibited. Souther and Shaffer,

2000, indicated that newly-germinated cypress seedlings (less than two weeks of

age) may be capable of surviving up to one and one-half months of submergence, but

will suffer complete mortality after a period of submergence longer than 57 days.

However, one-year-old seedlings experience up to a 75 percent survival rate when

they are submerged for as long as five months (Souther and Shaffer 2000).

Middleton (1995) suggests a longer dry period is necessary for cypress

establishment. According to Middleton (1995), cypress seedlings require a

drawdown of two years, and once established saplings will tolerate flooding better

than seedlings. Additionally, Clason (personal communication) stated that the dry

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WRDA 2007 Section 7006(e)(3) 3-37 October 2010

period should extend through the growing season (April-October) during the first

several years to allow seedlings to develop aggressive root systems.

Based on RSLR estimates and H&H modeling, it is estimated that much of

the LCA ARDC study area would become permanently inundated within 40 years.

Established freshwater swamp habitats can however provide good productivity,

even once permanently inundated, provided there is adequate hydrologic

connection, freshwater exchange, and an established stand with sufficient canopy

cover. According to Dr. Gary Shaffer (personal communication, October 2009),

cypress seedlings and trees should experience many pulses of nutrient-rich fresh

water during the growing season, and once the seedlings are above high water, they

can handle permanent flooding if the water is fresh and moving.

Invasive species also play a role in the degradation of freshwater swamp

habitat within the study area. It is well documented that nutria (Myocastor coypu)

will dramatically damage or destroy newly-planted seedlings and generally deter

cypress regeneration (Conner and Toliver 1987, 1988, Johnson and Foote 1997,

Flynn 1986, Conner and Day 1989, Myers et al. 1995, and Burnam and Mengak

2007). Myers et al. (1995) reported 100 percent mortality of unprotected seedlings

in southeastern Louisiana and found that PVC protectors were an effective

deterrent against nutria. In most cases, nutria seek out newly-planted seedlings

and remove enough of the bark to kill the tree, normally within a few days or weeks.

Nearly all mitigation banks that plant seedlings in areas where nutria exist use

rodent guards or some form of nutria protection. Methods to control nutria include:

habitat modification, exclusion, repellants, toxicants, trapping, and shooting

(Burnam and Mengak 2007). Habitat modification may only prove partiallyeffective within the LCA ARDC study area because much of the area would become

moderately inundated, which is ideal habitat for nutria. Repellants are marginally

effective only in the short-term. Zinc phosphate is the only toxicant registered for

nutria control, but may not be effective in a swamp environment because it may get

diluted. Trapping and shooting may be effective, but would require coordination

with the Louisiana Department of Wildlife and Fisheries and would be difficult to

implement this method as part of any proposed action at this time. Therefore, it was

determined that the most feasible method of nutria control would be an exclusion

device that creates a barrier between the nutria and the tree, such as nutria guards.

Nutria guards would act as a barrier on the newly-planted seedlings until the

seedlings are large enough that the nutria would no longer damage or kill the tree.

In summary, it was determined that vegetative plantings along with the

reestablishment of hydrologic connectivity are essential in highly degraded areas

(NE-2 and SE-2) to reestablish a productive stand and adequate canopy cover where

natural regeneration would not likely occur within the period of record and before

the effects of RSLR permanently inundated the system. Permanent inundation

would prevent planted or naturally regenerated species from becoming established;

however, the added hydrologic connectivity will allow for continued success of an

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WRDA 2007 Section 7006(e)(3) 3-38 October 2010

already established swamp. Vegetative plantings are also needed for native trees to

become reestablished and overcome competition from exotic and invasive species.

Nutria exclusion methods will be included on all plantings to prevent nutria from

damaging or killing newly-planted seedlings.

3.3.2 Description of Alternative Plans

Descriptions of all 45 alternatives developed are listed in Table 3.3. A matrix of

management measures used to formulate each alternative is presented in Table 3.4.

3.3.3 Screening/Evaluation of Alternative Plans

Once developed, all alternatives were evaluated. This evaluation process was based

on the ability of each alternative to meet project objectives, information gathered

from field investigations, technical discussions, the overall effectiveness of each

alternative, and the adverse environmental impacts that may result from the

alternatives in question. Results of the screening were previously presented in

Table 3.3. The rationale utilized for each screening criteria is detailed below.

• Ability to Meet Project Objectives and Alternative

Effectiveness – Each alternative was evaluated on the basis of its

ability to meet the four project objectives described in Section 2.4.2 of

this report. Each action listed in the initial array of alternatives is

made up of a combination of measures that were retained based on

their ability to meet one or more of the project objectives. Therefore, a

comparison was made between the alternatives to ascertain the degree

to which the overall list of objectives would be accomplished by

implementation of the proposed action. Some alternatives were not

retained if a similar, but different alternative was deemed to be more

effective in accomplishing the stated project objectives.

• Information Gathered from Field Investigations – The initial

array of alternatives was also evaluated, based on information and

data gathered during field investigations. For portions of the study

area these field investigations helped to determine the level to which

hydrologic connectivity exists, the existence of gaps within the dredged

material berm and railroad grade, the level of existing degradation and

the corresponding need for restoration, and the feasibility of

implementing each alternative. This information helped determine

which actions should be retained or screened out.

• Adverse Environmental Impacts – Any adverse environmental

impacts that would result from the proposed alternatives were

considered throughout the screening process as well. The

environmental impacts considered ranged from habitat loss that would

occur to reductions

130
Table 3.4. Matrix of Management Measures Used to Formulate the Alternatives 1

23

BO-14 BO-15 BO-16 BO-23 BO-24 CC-01 CC-03 HC-01 HC-03 MPDT-6 MPDT-8 VE-04 VP-01 VP-02

Openings on northbank ARDC,strategicallylocated, NE-2

Openings on southbank ARDC,strategicallylocated, SE-2

Openings on southbank ARDC,strategicallylocated, SE-1

Openings onrailroad grade,strategicallylocated, NE-1/NE-2

Openings onrailroad grade,strategicallylocated, SE-1/SE-2

Conveyancechannel, NE-1/NE-2

Conveyancechannel, SE-1/SE-2

Beneficial use of dredgedmaterial from conveyancechannels, NE-1/NE-2

Beneficial use of dredgedmaterial from conveyancechannels, SE-1/SE-2

NE-2 dredging thepullboat channel

Use dredged ARDCopening material tocreate additionalhabitat

Use dredgedrailroadmaterialto create additionalhabitat

Vegetative planting,such as (includingbald cypress andtupelo seedlings), indegraded areas

Vegetative planting, such as(including water oak andsweetgum seedlings), onmaterial placed from excavationof the dredgedmaterial berms.

1   

2    

3    

4     

5     6     7    

8     

9     

10     

11    

12     

13    14     

15     

16      

17    

18    

19   

20    

21      

22      

23     

24      

25      

26      

27     

28     

29     

30      

31    

32     

33        

34        35    

36       

37        38           

39       

40       

41        

42       

43        

44          

45       

Measures

Alternatives

WRDA 2007 Section 7006(e)(3) 3-39 October 2010

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in environmental parameters such as water quality. The cumulative

impacts to the local, state, and national resources similar to the study

area were also considered. Only proposed actions with minimal to no

adverse environmental impacts were retained for the final array.

Additional discussions involved aspects of each proposed alternative which could

potentially effect screening decisions.

3.3.4 Alternative Plans Not Carried Forward for Further Analysis

Due to the need to facilitate flow from the interior swamp to the ARDC, it was

determined that interface connections alone would not create enough connectivity.

A true hydraulic connection would be needed to ensure enough water exchange

between the ARDC and the swamp. Alternatives that did not have conveyance

channels were eliminated and only alternatives with conveyance channels were

retained through to the final array of alternatives (Table 3.3).

Alternatives were also eliminated if they included channel dredging. It was

determined that the bayou has already reached a natural equilibrium and would

therefore silt back in within a few years of over-excavating. Therefore, the

implementation of channel dredging would provide reduced benefits and would be

considered unsustainable. Alternatives which did not include the implementation

of vegetative plantings, within the most highly-degraded portions of the study area,

were eliminated based on the justification described in Section 3.3.1.1.

3.4 FINAL ARRAY OF ALTERNATIVES

(ALTERNATIVES STUDIED IN DETAIL)

Each alternative within the final array was retained from the initial array of

alternatives (Table 3.3). Seven alternatives plus the no-action alternative were

further evaluated. Of the seven alternatives, three are individual alternatives,

while the other four are combinations of these three. All alternatives within the

final array would have no adverse impacts on flood control, navigation, recreation,

or any type of Federal or non-Federal project.

3.4.1 No-Action Alternative (Future Without Project condition)

The No-Action Alternative consists of not implementing any restoration actions in

the LCA ARDC study area and is the Future Without Project (FWOP) condition to

which each alternative in the Final Alternative Array will be compared. This

alternative would not address any of the project objectives stated in Section 2.4.2.

Consideration of the No-Action Alternative is required by National Environmental

Policy Act [NEPA §1502.14(d)] and the current Federal Principles and Guidelines

(P&G §1.10.1).

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WRDA 2007 Section 7006(e)(3) 3-41 October 2010

3.4.2 Alternative 33 (NE-1/NE-2)

Alternative 33 (Figure 3.4) includes:

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

channel in the north bank of the ARDC also extending through the

railroad grade into NE-1 to add connectivity between NE-1, NE-2, and the

ARDC.

• Dredged material (5.0 acres) from the bank openings and the conveyance

channels would be sidecast on both sides of the proposed channels. Gaps

will be left in the disposal berms so sheet flow is not reduced.

• One cut would be created in the railroad grade approximately 0.9 miles

north of the ARDC to improve sheet flow.

• Initial and secondary vegetative plantings of bottomland

hardwood/freshwater swamp tree species on 5.0 acres of dredged material

berms.

• Initial and secondary vegetative plantings of freshwater swamp tree

species within 438 acres of the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

Three natural low areas or relict channels have been identified as potential bank

opening and conveyance channel sites. Openings would enable impounded water to

be drained from the swamp and provide hydrologic connectivity between the swamp

and the ARDC. Additionally, the placement of a cut in the railroad grade would

provide further hydrologic connectivity between NE-1 and NE-2. Openings would

promote the introduction of freshwater, sediments, and nutrients into the swamp

and allow the oxidation of sediments and removal of toxic metabolites. This

alternative is anticipated to improve the degraded swamp and decrease the

transition to marsh and ultimately, open water. This alternative represents the

minimum effort that would meet the goals and objectives of the project.

Alternative 33 would benefit approximately 1,602 acres of existing freshwater

swamp, recreate 144 acres of freshwater swamp from freshwater marsh, and create

5.0 acres of upland habitat from dredged material placement. This alternative

would address all of the project objectives stated in Section 2.4.2.

All excavation through the dredged material berms, as well as the conveyance

channels through the swamp, would be based on four design cross-sections

(Figures 3.5 through 3.8). These cross-sections were developed in an effort to mimic

natural, existing channels within the study area, which have been determined to be

self-maintaining. Several existing channels were surveyed for depth, dimension,

133
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 33

Map ID: 27850108-1868

LITTLE BAYOU CHENE BLANC

NE-2

SE-2

NE-3

SE-1

NE-1

Railroad

Grade 956 Acres

Secondary

Impact Area

438 Acres

Proposed

Vegetative

Planting

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

BAYOU

BAYOU CHENE BLANC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

BLANC

CHENE

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

SE-1

Material Berm

Notes:Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 3.4

134
25 ft 25 ft 20 ft

Existing TreesTo Remain

Trees To Be Planted

Existing TreesTo Be Removed

-5 ft Elev

1.3 ft Elev

Average WaterLevel (Elev 0.7 ft +/-)

Existing Grade (Elev 18.7 ft +/-)

70 ft +/-

25 ft +/- 25 ft +/- Varies 50 ft +/-

Existing TreesTo Remain

Varies 50 ft +/-

Trees To Be Planted

3h to 1v Slope

4h to 1v Slope

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to Scale

Source: GEC

Typical 70 ft. Cross Section through ARDC Dredged Material Berm

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Area

Figure: 3.5

135
Existing Grade (Elev 1.0 ft +/-)

10 ft 17 ft 5 ft

Existing TreesTo Remain

Trees To BePlanted

Existing TreesTo Be Removed

-5.0 Elev

Average WaterLevel (Elev 0.7 ft +/-)

20 Ft

70 ft +/-

25 ft +/- 25 ft +/-

4h to 1v Slope

10 ft 17 ft 5 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to Scale

Source: GEC

Typical 70 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Dimensions

Figure: 3.6

136
10 ft 12 ft 5 ft

Existing TreesTo Remain

Trees To BePlanted

-3.0 Elev

Existing TreesTo Be Removed

Average WaterLevel (Elev 0.7 ft +/-)

20 ft 15 ft +/- 15 ft +/-

Existing Grade ( Elev 1.0 ft +/-)

50 ft +/-

4h to 1v Slope

10 ft 12 ft 5 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to ScaleSource: GEC

Typical 50 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Figure: 3.7

137
10 ft 5 ft 9 ft

Average WaterLevel (Elev 0.7 ft)

-2.0 ft Elev

Existing TreesTo Remain

Trees To BePlanted

Existing TreesTo Be Removed

Existing Grade ( Elev 1.0 ft +/-)

30 ft +/-

10 ft +/-

4h to 1v Slope

10 ft +/- 10 ft 10 ft 5 ft 9 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to ScaleSource: GEC

Typical 30 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Figure: 3.8

138
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-47 October 2010

and profile. The cross-sections include a 70-foot wide cut section with benches

through the dredged material berm, a 70-foot wide cut section, a 50-foot wide cut

section and a 30-foot wide cut section. The benches are 25-foot wide flat areas,

located above the average water level, on both sides of the conveyance channel.

These benches will be included in the portions of the conveyance channel to be cut

through the existing dredged material berms. The 70-foot cut section with benches

was designed to allow increased amounts of flow to pass beyond the existing

dredged material berm during high-water events. The material dredged from the

existing berms would be placed along the swamp-side of the excavated cut as new

bottomland hardwood habitat. All material dredged during construction of the

conveyance channels would be placed along the channels, with gaps included, to

allow sufficient sheet flow to be conveyed from the swamp. The quantities

associated with each alternative are found in Table 3.5. A typical depiction of the

conveyance channels is found in Figure 3.9.

Table 3.5. Alternative Quantities

Footprints (Acres) Excavation (Cubic Yards)*

Berm Swamp

Alternative

Slopes

and

Benches

Channel Channel

10’

Gaps

and

Stumps

Material

Placement Total

Dredged

Material

Berm Cut

Channel

Cut

Total

33 1.8 0.8 17.8 5.8 5.0 31.2 13,753 81,694 95,447

34 2.5 0.9 9.6 3.1 2.7 18.8 27,867 45,873 73,740

35 1.8 0.6 6.6 2.1 2.2 13.3 25,527 34,941 60,468

36 4.3 1.7 27.4 8.8 7.8 50.0 41,620 127,567 169,187

37 4.3 1.5 16.2 5.2 4.9 32.1 53,394 80,814 134,208

38 3.6 1.4 24.4 7.9 7.2 44.5 39,280 116,635 155,915

39 6.1 2.3 34.0 11.0 9.9 63.3 67,147 162,508 229,655

3.4.3 Alternative 34 (SE-1/SE-2)

Features of Alternative 34 (Figure 3.10) include:

• One dredged material bank opening and one bifurcated conveyance

channel in the south bank of the ARDC in SE-1 with the conveyance

channel extending through the railroad grade into SE-1 would facilitate

hydrologic connectivity between the ARDC, SE-1, and SE-2.

• Dredged material (2.7 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

will be left in the disposal berms so sheet flow is not reduced. Vegetative

plantings of bottomland hardwood/freshwater swamp tree species on

2.7 acres of dredged material berm.

• Two cuts would be created in the railroad grade to improve sheet flow.

One cut would be approximately 0.9 miles south of the ARDC. The second

cut would be approximately 2.0 miles south of the ARDC.

• Initial and secondary vegetative plantings of freshwater swamp tree

species within 487 acres of the swamp floor.

139
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana Source: USDA/GEC

Scale:

Date: January 2010

TYPICAL CONVEYANCE CHANNEL

Map ID: 27850108-1889

Amite River Diversion Canal

70' Channel Through Existing

Dredge Material Berm and Swamp:

20' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -5.0' +/-

50' Channel Through Swamp:

20' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -3.0' +/-

30' Channel Through Swamp:

10' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -2.0' +/-

1:5,600

0 200 400 600

Feet

Map Extent

NE-1 NE-2

SE-2

SE-1 SW-2

NW-2

Amite River

NE-3

Diversion Canal

Legend

30' Channel

50' Channel

70' Channel

Cut Through Existing Dredge Material Berm

Dredge Material & Stump Placement

Subunits

Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Figure: 3.9

SE-1

140
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 34

Map ID: 27850108-1869

SE-1

SE-2

BLIND RIVER

NE-1

Railroad

Grade

1,033 Acres

Secondary

Impact Area

487 Acres

Proposed

Vegetative

Planting

426 Acres

Primary

Impact Area

Footprint =

18.8 Acres

AMITE RIVER DIVERSION CANAL NE-2

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm 87 sq. ft. Dredged Material Berm

SE-1

Notes:Footprint acreage equalssum of all Dredged MaterialBerms, Conveyance Channels,and Cuts Through ExistingDredged Material Berms.Spaces between DredgedMaterial Berms are shownlarger than actual size forgraphic purposes.

Figure: 3.10

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WRDA 2007 Section 7006(e)(3) 3-50 October 2010

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

The opening in the south bank of the ARDC, coupled with the two gaps in the

railroad grade, would facilitate hydrologic connectivity between the ARDC, SE-1,

and SE-2. These openings would promote an influx of fresh water, nutrients, and

sediments into these areas, which would help flush high salinity waters from the

swamp, restore the degraded swamp habitat, and reverse the transition to marsh

and open water. Alternative 34 would benefit approximately 1,459 acres of existing

freshwater swamp, recreate 146 acres of freshwater swamp from freshwater marsh,

and create 2.7 acres of upland habitat from dredged material placement. This

alternative would address all the project objectives stated in Section 2.4.2.

Descriptions of the proposed cuts through the dredged material berms and the

conveyance channels proposed within the primary impact areas will be

implemented as described for Alternatives 33 and 39 in Sections 3.4.2 and 3.4.8,

respectively.

3.4.4 Alternative 35 (SE-1)

Features of Alternative 35 (Figure 3.11) include:

• One dredged material bank opening and one bifurcated conveyance

channel in the south bank of the ARDC in SE-1.

• Dredged material (2.2 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

will be left in the disposal berms so sheet flow is not reduced.

• Initial and secondary vegetative plantings of bottomland

hardwood/freshwater swamp tree species on 2.2 acres of the dredged

material berms.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

The opening would promote an influx of fresh water, nutrients, and sediments into

these areas, which would help flush high salinity waters from the swamp, improve

the degraded swamp habitat, and decrease the transition to marsh and open water.

Alternative 35 would benefit approximately 820 acres of existing freshwater swamp

and create 2.2 acres of upland habitat from dredged material placement. This

alternative would address all the project objectives stated in Section 2.4.2.

Descriptions of the proposed cuts through the dredged material berms and the

conveyance channels proposed within the primary impact areas will be

implemented as described for Alternatives 33 and 39 in Sections 3.4.2 and 3.4.8,

respectively.

142
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 35

Map ID: 27850108-1870

SE-1 PETITE AMITE RIVER

NE-1

Railroad

Grade

377 Acres

Secondary

Impact Area

443 Acres

Primary

Impact Area

Footprint =

13.3 Acres

AMITE RIVER DIVERSION CANAL

NE-2

SW-2

SE-2

1:20,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade Cuts

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

Notes:Footprint acreage equals sum of all Dredged MaterialBerms, Conveyance Channels, and Cuts ThroughExisting Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 3.11

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WRDA 2007 Section 7006(e)(3) 3-52 October 2010

3.4.5 Alternative 36 (NE-1/NE-2, SE-1/SE-2)

Features of Alternative 36 (Figure 3.12: Combinations of Alternatives 33 and 34)

include:

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

cut in the north bank of the ARDC also extending through the railroad

grade into NE-1 to add connectivity between NE-1 and NE-2, and the

ARDC.

• One dredged material bank opening and one bifurcated conveyance

channels in the south bank of the ARDC in SE-1 with the conveyance

channels extending through the railroad grade into SE-1 would facilitate

hydrologic connectivity between the ARDC, SE-1, and SE-2.

• Dredged material (7.8 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

will be left in the disposal berms so sheet flow is not reduced.

• Three cuts would be created in the railroad grade to improve sheet flow.

One cut would be approximately 0.9 miles north of the ARDC. The

second cut would be approximately 0.9 miles south of the ARDC. The

third cut would be approximately 2 miles south of the ARDC.

• Initial and secondary vegetative plantings of bottomland

hardwood/freshwater swamp tree species on 7.8 acres of the dredged

material berms.

• Initial and secondary vegetative plantings of freshwater swamp tree

species within 925 acres of the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

The openings would restore hydrologic connectivity of the habitats north and south

of the ARDC with the ARDC. North of the ARDC, proper drainage of impounded

waters in NE-2 would promote the restoration of the degraded swamp and the

decreasing of marsh to swamp forest. South of the ARDC, the swamp habitats

would benefit from the influx of fresh water, nutrients, and sediments.

Alternative 36 would benefit approximately 3,061 acres of existing freshwater

swamp, recreate 290 acres of freshwater swamp from freshwater marsh, and create

7.8 acres of upland habitat from dredged material placement. This alternative

would address all of the project objectives stated in Section 2.4.2.

Descriptions of the proposed cuts through the dredged material berms and the

conveyance channels proposed within the primary impact areas will be

implemented as described for Alternatives 33 and 39 in Sections 3.4.2 and 3.4.8,

respectively.

144
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 36

LITTLE BAYOU CHENE BLANC

Map ID: 27850108-1871

SE-1

NE-2 NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER Railroad Grade

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

Footprint =

18.8 Acres

1,033 Acres

Secondary

Impact Area

426 Acres

Primary

Impact Area

487 Acres

Proposed

Vegetative

Planting

SW-2

ALLIGATOR BAYOU

1:40,000

0 2,000 4,000 6,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes:Footprint acreage equals sum of all DredgedMaterial Berms, Conveyance Channels, and CutsThrough Existing Dredged Material Berms.Spaces between Dredged Material Berms areshown larger than actual size for graphic purposes.

Figure: 3.12

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WRDA 2007 Section 7006(e)(3) 3-54 October 2010

3.4.6 Alternative 37 (SE-1/SE-2, SE-1)

Features of Alternative 37 (Figure 3.13: Combinations of Alternatives 34 and 35)

include:

• One dredged material bank opening and one bifurcated conveyance

channel in the south bank of the ARDC in SE-1 with the conveyance

channel extending through the railroad grade into SE-1 would facilitate

hydrologic connectivity between the ARDC, SE-1, and SE-2.

• One bank opening and conveyance channels in the south bank of the

ARDC in SE-1.

• Two cuts would be created in the railroad grade to improve sheet flow.

One cut would be approximately 0.9 miles south of the ARDC. The second

cut would be approximately 2.0 miles south of the ARDC.

• Dredged material (4.9 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

will be left in the disposal berms so sheet flow is not reduced.

• Initial and secondary vegetative plantings of bottomland

hardwood/freshwater swamp tree species on 4.9 acres of dredged material

berms.

• Initial and secondary vegetative plantings of freshwater swamp tree

species within 487 acres of the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

The openings would restore hydrologic connectivity of the area south of the ARDC

with the ARDC. Subunits SE-1 and SE-2 would benefit from the influx of fresh

water, nutrients, and sediments. This would maintain the swamp forests in SE-1

and improve the degraded swamp forest in the eastern portion of SE-1 and in SE-2,

as well as decrease the transition from swamp to marsh to ultimately open water in

SE-2. Alternative 37 would benefit approximately 2,279 acres of existing freshwater

swamp, recreate 146 acres of freshwater swamp from freshwater marsh, and create

4.9 acres of upland habitat from dredged material placement. This alternative

would address all the project objectives stated in Section 2.4.2.

Descriptions of the proposed cuts through the dredged material berms and the

conveyance channels proposed within the primary impact areas will be

implemented as described for Alternatives 33 and 39 in Sections 3.4.2 and 3.4.8,

respectively.

146
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 37

Map ID: 27850108-1872

!(

SE-1 SE-2

BLIND RIVER

PETITE AMITE RIVER

NE-1

Railroad

Grade 377 Acres

Secondary

Impact Area

443 Acres

Primary

Impact Area

Footprint = 13.3 Acres

AMITE RIVER DIVERSION CANAL

NE-2

SW-2

Footprint = 18.8 Acres

1,033 Acres

Secondary

Impact Area

426 Acres

Primary

Impact Area

487 Acres

Proposed

Vegetative

Planting

1:26,000

±

0 1,000 2,000 3,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact Area

!( Existing Railroad Grade Cuts

Proposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of all Dredged MaterialBerms, Conveyance Channels, and Cuts Through ExistingDredged Material Berms. Spaces between Dredged MaterialBerms are shown larger than actual size for graphic purposes.

Figure: 3.13

147
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WRDA 2007 Section 7006(e)(3) 3-56 October 2010

3.4.7 Alternative 38 (NE-1/NE-2, SE-1)

Features of Alternative 38 (Figure 3.14: Combinations of Alternatives 33 and 35)

include:

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

cut in the north bank of the ARDC also extending through the railroad

grade into NE-1 to add connectivity between NE-1 and NE-2.

• One bank opening and conveyance channels in the south bank of the

ARDC in SE-1.

• One cut would be created in the railroad grade approximately 0.9 miles

north of the ARDC to improve sheet flow.

• Dredged material (7.2 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

will be left in the disposal berms so sheet flow is not reduced.

• Initial and secondary vegetative plantings of bottomland

hardwood/freshwater swamp tree species on 7.2 acres of dredged material

berms.

• Initial and secondary vegetative plantings of freshwater swamp tree

species within 438 acres of the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

Implementation of this alternative would restore the hydrologic connectivity of

NE-1, NE-2, and SE-1 with the ARDC. Within NE-1 and NE-2, the benefits would

consist of proper drainage of impounded waters from NE-2, improvement of the

degraded swamp, and decreasing the transition from swamp to march to ultimately

open water. The cut in the south bank of ARDC would restore the hydrologic

connectivity of the ARDC with SE-1 and help to maintain the health of the swamp

forest along the western portion of SE-1. Alternative 38 would benefit

approximately 2,422 acres of existing freshwater swamp, recreate 144 acres of

freshwater swamp from freshwater marsh, and create 7.2 acres of upland habitat

from dredged material placement. This alternative would address all of the project

objectives stated in Section 2.4.2.

Descriptions of the proposed cuts through the dredged material berms and the

conveyance channels proposed within the primary impact areas will be

implemented as described for Alternatives 33 and 39 in Sections 3.4.2 and 3.4.8,

respectively.

3.4.8 Alternative 39 (NE-1/NE-2, SE-1/SE-2 – All Subunits Combined)

Features of Alternative 39 (Figure 3.15: Combinations of Alternatives 33, 34 and

35) include:

148
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 38

Map ID: 27850108-1873

LITTLE BAYOU CHENE BLANC

SE-1

NE-2

NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER Railroad Grade 377 Acres Secondary Impact Area

443 Acres

Primary

Impact Area

Footprint =

13.3 Acres

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

NW-2

ALLIGATOR BAYOU

1:40,000

0 2,000 4,000 6,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms areshown larger than actual size for graphic purposes.

Figure: 3.14

149
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 39

LITTLE BAYOU CHENE BLANC

Map ID: 27850108-1874

SE-1

NE-2 NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER Railroad Grade 377 Acres Secondary Impact Area

443 Acres

Primary

Impact Area

Footprint =

13.3 Acres

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

Footprint =

18.8 Acres

1,033 Acres

Secondary

Impact Area

426 Acres

Primary

Impact Area

487 Acres

Proposed

Vegetative

Planting

ALLIGATOR BAYOU

1:40,000

0 2,000 4,000 6,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of all DredgedMaterial Berms, Conveyance Channels,and CutsThrough Existing Dredged Material Berms.Spaces between Dredged Material Berms areshown larger than actual size for graphic purposes.

Figure: 3.15

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WRDA 2007 Section 7006(e)(3) 3-59 October 2010

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

cut in the north bank of the ARDC also extending through the railroad

grade into NE-1 to add connectivity between NE-1 and NE-2.

• One dredged material bank opening and one bifurcated conveyance

channel in the south bank of the ARDC in SE-1 with the conveyance

channel extending through the railroad grade into SE-1 to add

connectivity between SE-1 and SE-2, and the ARDC.

One opening and one conveyance channel in the south bank of the ARDC

in SE-1.

• Dredged material (9.9 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

will be left in the disposal berms so sheet flow is not reduced.

• Three cuts would be created in the railroad grade to improve sheet flow.

One cut would be approximately 0.9 miles north of the ARDC. The second

cut would be approximately 0.9 miles south of the ARDC. The third cut

would be approximately two miles south of the ARDC.

• Initial and secondary vegetative plantings of bottomland hardwood/

freshwater swamp tree species on 9.9 acres of dredged material berms.

• Initial and secondary vegetative plantings of freshwater swamp tree

species within 925 acres of the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

Implementation of this alternative would restore the hydrologic connectivity

between NE-1, NE-2, SE-1, and SE-2 with the ARDC. This alternative would

provide the maximum effort to restore hydrologic connectivity of the wetlands to the

ARDC. Alternative 39 would benefit approximately 3,881 acres of existing

freshwater swamp, recreate 290 acres of freshwater swamp from freshwater marsh,

and create 9.9 acres of upland habitat from dredged material placement. This

alternative would address all of the project objectives stated in Section 2.4.2.

All excavation to take place for the cuts through the dredged material berms, as

well as for the conveyance channels through the swamp, would be based on four

design cross-sections (Figures 3.5 through 3.8). These cross-sections were developed

in an effort to mimic natural, existing cuts within the study area, which have been

determined to be self-maintaining. The cross-sections include a 70-foot wide cut

section with benches, a 70-foot wide cut section, a 50-foot wide cut section and a 30-

foot wide cut section. The benches are 25-foot wide flat areas, located above the

average water level, on both sides of the conveyance channel. These benches will be

included in the portions of the conveyance channel to be cut through the existing

dredged material berms. The 70-foot cut section with benches is designed to allow

increased amounts of flow to pass beyond the existing dredged material berm

during high-water events. The material dredged from the existing berms would be

151
Alternatives Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) 3-60 October 2010

placed along the swamp-side of the excavated cut as new bottomland hardwood

habitat. All material dredged during construction of the conveyance channels would

be placed along the channels, with gaps included, to allow sufficient sheet flow to be

conveyed from the swamp. Table 3.5 gives specific quantities and areas associated

with the construction of the final array of alternatives.

3.5 COMPARISON OF ALTERNATIVE PLANS

Of the seven alternatives that make up the final array, three are individual

alternatives, while the other four are combinations of these three. The effects of the

alternatives within the final array were evaluated against the No Action alternative

(FWOP condition) in order to determine their overall impact over the 50-year period

of analysis (2012 - 2062) of the project. Alternatives were then compared to each

other (see Table 3.15). This includes environmental impacts to significant resources,

WVA benefits, cost and contributions to project goals, planning objectives and

constraints, contributions to the Federal objective, and the Principles and

Guidelines (P&G)’s four evaluation criteria (completeness, effectiveness, efficiency

and acceptability). A comparison of the features included in each alternative within

the final array is found in Table 3.6.

Table 3.6. Comparison of Final Array of Alternatives

Alternative

North

Bank

Openings

South

Bank

Openings

Additional

Railroad

Grade

Openings

Berm

Plantings

(Acres)

Swamp

Plantings

(Acres)

33 3 0 1 5.0 438

34 0 1 2 2.7 487

35 0 1 0 2.2 0

36 3 1 3 7.8 925

37 0 2 2 4.9 487

38 3 1 1 7.2 438

39 3 2 3 9.9 925

3.5.1 Cost Estimates for the Final Array

As part of the further development of the remaining alternatives, preliminary

construction costs were developed to use in the Cost Effectiveness/Incremental Cost

Analysis (CE/ICA) analysis. These costs are listed in Table 3.7. While the measures

and alternatives recommended for the areas north and south of the ARDC are

independent of each other, cost savings are obtained by combining the areas into

one alternative (e.g., Alternative 39). These savings are represented by the

reductions in the various mobilization and demobilization costs incurred through

152
1

Table 3.7. Summary of Costs Estimates for the Final Array 2

Item Alt. 33 Alt. 34 Alt. 35 Alt. 36 Alt. 37 Alt. 38 Alt. 39

Mob/Demob $250,000 $150,000 $150,000 $300,000 $200,000 $300,000 $350,000Earthwork $462,000 $332,000 $262,000 $788,000 $583,000 $698,000 $1,050,000Erosion Protection $46,000 $23,000 $23,000 $69,000 $45,000 $69,000 $92,000VegetativePlantings $819,000 $906,000 $6,000 $1,720,000 $909,000 $822,000 $1,730,000Surveying $54,000 $22,000 $22,000 $70,000 $70,000 $70,000 $86,000Markups $631,000 $564,000 $176,000 $1,152,000 $695,000 $756,000 $1,289,000Planning Eng. &Design $189,000 $169,000 $53,000 $346,000 $209,000 $227,000 $387,000ConstructionManagement $110,000 $99,000 $31,000 $202,000 $122,000 $132,000 $226,000Total ConstructionCosts $2,560,000 $2,270,000 $720,000 $4,650,000 $2,830,000 $3,070,000 $5,210,000(25% Contingency) $640,000 $568,000 $180,000 $1,160,000 $708,000 $768,000 $1,300,000Real Estate $136,000 $144,000 $62,000 $259,000 $185,000 $178,000 $301,000Total First Costs* $3,340,000 $2,980,000 $962,000 $6,070,000 $3,720,000 $4,020,000 $6,810,000Interest DuringConstruction** $440,000 $390,000 $126,000 $797,000 $489,000 $528,000 $894,000Total ConstructionCost $3,780,000 3,370,000 $1,090,000 $6,870,000 $4,210,000 $4,550,000 $7,700,000Annual OMRR&RCosts $10,000 $7,000 $7,000 $11,000 $8,000 $11,000 $12,000Average AnnualCosts** $197,000 $174,000 $61,000 $351,000 $217,000 $236,000 $394,000

3

*First Quarter 2010 Dollars; ** Average annual costs were determined over the six-year construction period with a discount rate of 4.375 percent; 4

Costs presented are preliminary costs used for planning purposes only and do not represent a fully funded cost estimate. 5

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the implementation of Alternatives 33, 34, and 35, separately. Average annual costs

were determined over the six-year construction period with a discount rate of 4.375

percent. The rationale and assumptions used for the development of unit costs and

all cost estimates are described in Appendix L.

3.5.2 Wetland Value Assessment Model

WVA models are ecological benefit models designed to evaluate the existing, FWOP,

and FWP condition. The CWPPRA WVA Swamp model was chosen for this study

area over the Fresh Marsh model, even though portions of the study area have less

than a 33 percent canopy cover, because the area provides functions and values

more closely associated with a freshwater swamp than a freshwater marsh. The

WVA produced Average Annual Habitat Units (AAHUs), a measure of change, for

the 50-year period of analysis when comparing the FWP to the FWOP. The Habitat

Suitability Index (HSI) is a unit less number bounded by 0 and 1 where 0

represents no habitat and 1 represents optimum habitat. The HSI for a particular

area is multiplied by the size of the area for which the HSI was calculated to create

the Habitat Unit (HU) value (HU = HSI x size of habitat). AAHUs are calculated by

dividing the total number of HUs gained or lost as a result of a proposed action by

the period of analysis. Performance measures and targets for the benefits to be

achieved are defined in the Adaptive Management Plan in Appendix I.

The WVA calculates the benefits (FWP as compared to the FWOP) for years 0, 1,

10, 25, and 50. The habitat units for each from year 1 to year 50 are calculated.

The cumulative habitat units generated for the 50 year period of analysis divided by

50 will determine the AAHU. The 50-year period of analysis is from 2012–2062.

Thus the WVA accounts for tree growth and the timing for ecological restoration.

For example, if the net change between the FWOP and FWP is a +0.2 over 100 acres

over the 50-year period of evaluation, then that alternative would produce 20

AAHUs of ecological benefit. The model is based upon Habitat Suitability Indices

(HSIs) that are developed by evaluating several variables at the site and predicting

the future changes, with and without the project. For the freshwater swamp model,

variables include stand structure, stand maturity, water regime, and mean high

salinity during the growing season. For the bottomland hardwoods model, variables

include tree species composition, stand maturity, understory/midstory, size of

contiguous forested area, suitability and traversability of surrounding land uses,

and disturbance.

Details concerning the professional judgment and model-generated input data

utilized in the WVA model are included in the WVA Project Information Sheet,

found in Appendix K of this report. The WVA Suitability Index graphs were

developed according to the following assumptions:

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Variable V1 - Stand structure. Most swamp tree species do not produce hard

mast; consequently, wildlife foods predominantly consist of soft mast, other edible

seeds, invertebrates, and vegetation. Because most swamp tree species produce

some soft mast or other edible seeds, the actual tree species composition is not

usually a limiting factor. More limiting is the presence of stand structure to provide

resting, foraging, breeding, nesting, and nursery habitat and the medium for

invertebrate production. This medium can exist as herbaceous vegetation, scrubshrub/midstory cover, or overstory canopy and preferably as a combination of all

three.

This variable assigns the lowest suitability to sites with a limited amount of all

three stand structure components, the highest suitability to sites with a significant

amount of all three stand structure components, and mid-range suitability to

various combinations when one or two stand structure components are present.

Variable V2 - Stand maturity. Because of man's historical conversion of swamp,

the loss of swamp to saltwater intrusion, historical and ongoing timber harvesting,

and a reduced tree growth rate in the subsiding coastal zone, swamps with mature

sizeable trees are a unique but ecologically important feature. Older trees provide

important wildlife requisites such as snags and nesting cavities and the medium for

invertebrate production. Additionally, as the stronger trees establish themselves in

the canopy, weaker trees are out-competed and eventually die, forming additional

snags and downed treetops that would not be present in younger stands. The

suitability graph for this variable assumes that snags, cavities, downed treetops,

and invertebrate production are present in suitable amounts when the average

diameter-at-breast height (DBH) of canopy-dominant and canopy-codominant trees

is above 16 inches for baldcypress and above 12 inches for tupelogum and other

species. Therefore, stands with those characteristics are considered optimal for this

variable (SI = 1.0).

Another important consideration for this variable is stand density, measured in

terms of basal area. A scenario sometimes encountered in mature swamp

ecosystems is an overstory consisting of a very few, widely-scattered, mature

baldcypress. If stand density was not considered, and average DBH only, then

those stands would receive a high SI for this variable without providing many of the

important habitat components of a mature swamp ecosystem, specifically a suitable

number of trees for nesting, foraging, and other habitat functions. Therefore, the SI

for this variable is dependent on average DBH and basal area which is used as a

measure of stand density.

Variable V3 - Water regime. This variable considers the duration and amount of

water flow/exchange. Four flow/exchange and four flooding duration categories are

described to characterize the water regime. The optimal water regime is assumed

to be seasonal flooding with abundant and consistent riverine/tidal input and water

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flow-through (SI=1.0). Seasonal flooding with periodic drying cycles is assumed to

contribute to increased nutrient cycling (primarily through oxidation and

decomposition of accumulated detritus), increased vertical structure complexity

(due to growth of other plants on the swamp floor), and increased recruitment of

dominant overstory trees. In addition, abundant and consistent input and water

flow-through is optimal, because under that regime the full functions and values of

a swamp in providing fish and wildlife habitat are assumed to be maximized.

Temporary flooding is also assumed to be desirable. Habitat suitability is assumed

to decrease as water exchange between the swamp and adjacent systems is reduced.

The combination of permanently flooded conditions and no water exchange (e.g., an

impounded swamp where the only water input is through rainfall and the only

water loss is through evapotranspiration and ground seepage) is assumed to be the

least desirable (SI=0.1). Those conditions can produce poor water quality during

warm weather, reducing fish use and crawfish production.

Variable V4 - Mean high salinity during the growing season. Mean high

salinity during the growing season (March 1 to October 31) is defined as the average

of the upper 33 percent of salinity measurements taken during the specified period

of record. Although baldcypress is able to tolerate higher salinities than other

swamp species, species such as tupelogum and many herbaceous species are

salinity-sensitive. Optimal conditions are assumed to occur at mean high salinities

less than 1.0 ppt. Habitat suitability is assumed to decrease rapidly at mean high

salinities in excess of 1.0 ppt.

WVA Benefits. The benefits of the alternatives are directly linked to increases in

hydrologic exchange between the ARDC and the swamp (Figure 3.16). The critical

issue for the ecosystem restoration is to restore the connectivity to and from the

swamp. The H&H Model was used to assist in assigning values to V3, based on the

expected days of drying associated with each alternative. This connectivity would

not only create an exchange of freshwater, nutrients, and sediments, but it would

also alleviate the impounding that is occurring in NE-1 and NE-2. The WVA

analysis (Appendix K) used the information from the H&H modeling, to determine

the values to be used for the water regime variable. Table 3.8 depicts the net

habitat units (HUs) and the annualized cost associated with the No-Action

alternative and the final array, over the 50-year period of analysis. Estimates of

accretion are based upon work by Shaffer et al. 2006 and 2009. In areas of sediment

poor, but sufficient freshwater and nutrients, swamps were able to develop

accretions to balance RSLR. This information was incorporated in the evaluation of

the FWP for V3.

The WVA analyses were run for each alternative within the final array to determine

the quantitative benefits of each alternative, including the areas impacted by the

construction of the bank openings, conveyance channels, and dredged material

placement. This analysis took into account the fact that any future development of

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Figure 3.16. Project Benefits

Table 3.8. Summary of WVA Benefits of Final Array

Alternative

No.

Total Benefits

(HUs)

Annualized Benefits

(AAHUs)

No Action 0 0

35 16,680 334

34 29,428 589

33 33,973 679

37 46,109 922

38 50,653 1,013

36 63,402 1,268

39 80,081 1,602

Increased

Freshwater

Input

Increased

Nutrient

Input

Decreased

Impoundment

Increased

Sediment

Input

Increased

Regeneration

Increased

Tree Growth

Increased

Swamp

Health

Increased Swamp

Substrate Health

Increased

Hydrologic

Connectivity

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the dredged material berms, within the areas of impact, would have no effect on the

benefits generated by the final array. The WVA initial analysis was completed on

the primary and secondary impact areas for all alternatives for the low RSLR

scenario (Table 3.9, Figures 3.4 and 3.10 - 3.15). The WVA analysis was also run on

the intermediate and high RSLR scenarios for the NER and Recommended Plan.

The concept of RSLR was introduced in Sections 2.3.3.3 and 2.3.5.1 of the report.

Based on the fact that all alternatives within the final array implement similar

features, in areas with very little fluctuation in land elevations, it was determined

that RSLR would have the same effect on water levels for all alternatives in the

final array and little to no variance in water levels would occur.

Table 3.9 Computed Exchange Channel Flows with RSLR

With project with no RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 6,330 5,298 4,812 4,368 4,035

% time of inflow 23% 22% 29% 28% 28%

Volume outflow (ac-ft/yr) 6,874 7,160 3,392 3,696 4,088

% time of outflow 77% 78% 71% 72% 72%

With Project with 50 years of Low rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 23,175 20,734 14,522 13,503 12,903

% time of inflow 35% 34% 54% 53% 52%

Volume outflow (ac-ft/yr) 32,635 35,202 7,291 8,187 8,894

% time of outflow 65% 66% 46% 47% 48%

The primary and secondary impact areas for the final array of alternatives were

developed after examining existing conveyance channels found within the study

area. These channels are considered to be in a state of hydrologic equilibrium due to

the lack of sediment buildup observed, when compared to other channels found

within the same general area. The benefit areas for the proposed conveyance

channels were developed by observing the dimensions and configurations of the

drainage areas found along these existing channels.

The primary impact area would have more flow exchange and therefore more

sediments and nutrients than the secondary impact area. The volume of water,

which transports sediments and nutrients, is dependent on the duration of high

stages in the ARDC. During the short duration of high stages in the ARDC, the

benefits may be limited to the primary impact area. During normal hydrologic

cycles, the primary impact area would receive a higher flow exchange than the

secondary impact area. Table 3.10 and Figures 3.17 through 3.23 depict the net

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habitat units (HUs) obtained by the No-Action alternative and the final array over

the 50-year period of analysis, and Figure 3.24 depicts the net benefits gained. It is

apparent from the data that a net of 200 to 900 HUs is obtained for each of the

seven alternatives. It is also apparent that each alternative obtains the maximum

level of benefits at around year 25 and maintains these levels through the

remaining 25 years of the period of analysis. This shows that all alternatives within

the final array provide sustainable benefits. Maps depicting the impact acreages

utilized by the WVA model for each habitat type within the study and impact areas

are found in Appendix K.

Table 3.10. Final Array Benefits

Benefits Over the 50-Year Period of Analysis (HUs)

Alternative Year

0 1 10 25 50

33

No-Action 757 762 636 562 518

With Project 757 889 1047 1390 1466

Net 0 127 410 828 948

34

No-Action 607 611 545 506 461

With Project 607 697 875 1228 1308

Net 0 85 330 723 847

35

No-Action 471 474 410 358 291

With Project 471 547 611 756 766

Net 0 73 201 398 476

36

No-Action 1364 1373 1182 1068 979

With Project 1364 1586 1922 2618 2774

Net 0 213 740 1551 1795

37

No-Action 1078 1085 955 863 751

With Project 1078 1243 1486 1984 2074

Net 0 158 531 1121 1323

38

No-Action 1228 1236 1047 919 809

With Project 1228 1436 1657 2146 2232

Net 0 200 611 1226 1424

39

No-Action 1835 1843 1589 1423 1268

With Project 1835 2137 2535 3377 3542

Net 0 294 946 1954 2273

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Figure 3.17. Comparison of Benefits for Final Array, Alternative 33

Figure 3.18. Comparison of Benefits for Final Array, Alternative 34

Figure 3.19. Comparison of Benefits for Final Array, Alternative 35

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00

1600.00

0 20 40 60

Habitat Units

Years

Alternative 33

No-Action

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00

0 20 40 60

Habitat Units

Years

Alternative 34

No-Action

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

900.00

0 20 40 60

Habitat Units

Years

Alternative 35

No-Action

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Figure 3.20. Comparison of Benefits for Final Array, Alternative 36

Figure 3.21. Comparison of Benefits for Final Array, Alternative 37

Figure 3.22. Comparison of Benefits for Final Array, Alternative 38

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

0 20 40 60

Habitat Units

Years

Alternative 36

No-Action

0.00

500.00

1000.00

1500.00

2000.00

2500.00

0 20 40 60

Habitat Units

Years

Alternative 37

No-Action

0.00

500.00

1000.00

1500.00

2000.00

2500.00

0 10 20 30 40 50 60

Habitat Units

Years

Alternative 38

No-Action

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Figure 3.23. Comparison of Benefits for Final Array, Alternative 39

Figure 3.24. Net Benefits Gained by Final Array

Additionally, the H&H model shows that under the low RSLR estimate for the NoAction alternative, the areas of impact would be permanently inundated in 14

years. Without considering the impacts of biomass accretion, under the Future

With Project conditions, the area of impacts would not be considered permanently

inundated for 40 years. The introduction of freshwater, nutrients, and sediments,

even under permanent inundation, would still improve that swamp habitat (Gary

Shaffer, personal communication, October 2009). Low oxygen and reducing

conditions restrict tree growth in inundated conditions. However, improved flow

would increase oxygen and improve tree vigor, even in fully inundated conditions

(Gary Shaffer, personal communication, October 2009). Therefore, as long as

hydrologic connectivity is achieved and regeneration is established, benefits would

be realized under permanently inundated conditions and project success would not

be compromised. The plateaus depicted in Figures 3.17 through 3.24 indicate that a

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

3500.00

4000.00

0 10 20 30 40 50 60

Habitat Units

Years

Alternative 39

No-Action

0

500

1000

1500

2000

2500

0 10 20 30 40 50 60

Net Habitat Units

Years

Alt. 33

Alt. 34

Alt. 35

Alt. 36

Alt. 37

Alt. 38

Alt. 39

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state of natural equilibrium is obtained over the 50-year period of analysis. This

state of equilibrium is indicative of a system that would continue to exhibit

ecological benefits despite the fact that it is a permanently inundated system as

long as hydrologic connectivity is maintained. This is why it is critical to the

success of this project to implement vegetative plantings in the portions of the study

area which do not exhibit canopy cover and adequate stand densities, before

permanent inundation occurs.

The increase in drying days, which would occur for the first 40 years of the period of

analysis, would allow the substrate to oxidize, release bound nutrients, and allow

for substrate compaction. The benefits from the drying days would reverse the

conversion of swamp to marsh and open water (Shaffer et al., 2009, Bernard Wood

personal communication, July 2009). Accretion may also play a role in reducing the

effects of RSLR. It has been estimated that a net accretion of 8mm/year could be

achieved within the healthy swamp habitat found in the study area (Bernard Wood,

unpublished data, 2005 through 2009).

After comparing the final array of alternatives, based on the applicable criteria

including benefits and impacts, the PDT ranked the alternatives in the order

depicted in Table 3.11. These are rankings based on restoration opportunities

provided by each alternative and do not take into account project constraints such

as funding limitations. The rationale for selection of the Recommended Plan and is

further discussed in Sections 3.7 and 3.7.11.1 of this report.

Table 3.11. Ranking of Final Array

Rank Alternative Reasoning

1 39 Produces the most benefits of any alternative and

addresses the two most critical areas, plus SE-1 and NE-1.

2 36 Produces the second-most benefits of any alternative and

addresses the most critical areas, plus SE-1 and NE-1.

3 38 Produces benefits within the most critical areas, plus SE-1.

SE-1 is not considered as degraded as SE-2.

4 33 Includes the most critical area and benefits to NE-1.

5 37 Includes benefits for SE-1 and SE-2. Does not include the

most critical area, NE-2.

6 34 Includes benefits in a smaller portion of SE-1 and SE-2.

Does not include the most critical area, NE-2.

7 35 Includes benefits in SE-1 only. Does not include the most

critical areas.

8 No-Action Does not produce benefits within the study area.

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WVA Model Certification. The WVA model is completing model certification in

accordance with EC 1105-2-407, May 2005 Planning Models Improvement Program.

The model has undergone external review which is documented in the July 8, 2009,

Draft Model Certification Review Report for the Wetland Value Assessment Models

prepared by the Battelle Memorial Institute for the US Army Corps of Engineers,

Ecosystem Planning Center of Expertise. The responses to the Battelle review have

been submitted to the ECO-PCX. The ECO-PCX has reviewed the revisions and will

forward a recommendation to certify the model for use in the LCA projects. Since

the WVA was still in the process of being certified, the projects using the WVA

model were required to respond to specific comments related to the ongoing

certification process and the use of WVA on the specific project. The specific

comments and responses for the WVA as it relates to the LCA ARDC Modification

project can be found in Appendix K. Based on satisfactory responses to these

comments Planning Center of Expertise for Ecosystem Restoration has cleared the

WVA model for use in evaluating the alternatives considered in this report.

Hydraulic Analysis. The USACE Engineering Center River Analysis System

(HEC-RAS) program was used to simulate FWOP and FWP conditions. The HECRAS models are used to simulate flow exchange and flood duration for the proposed

actions. The results of the HEC-RAS model runs were then used to support the

WVA model. Specifically, the model results were used to quantify flow/exchange

and flooding duration (Variable V3) in the WVA calculations. The HEC-RAS model

was also used to assist in the evaluation of the impacts of RSLR.

WVA models are ecological benefit models designed to evaluate the project benefits

associated with a proposed action. The benefits of the alternatives are linked to the

flow exchange between the ARDC and the adjacent swamp (Variable V3). The

HEC-RAS program does not estimate project benefits nor predict project success. A

HEC-RAS model is a surface water model used to estimate stage and discharge

relationships.

3.5.3 Institute of Water Resources Planning Suite Analysis

Each alternative within the final array was evaluated through a cost-effectiveness

and incremental cost analysis (CE/ICA) by utilizing the Institute of Water

Resources (IWR)-Planning Suite software. The 50-year evaluation period for the

ARDC modification project was used. This software utilizes the annualized output

from the WVA Model (AAHUs) and the annualized costs of each alternative to

determine which proposed actions are deemed cost effective. Of the actions

considered cost-effective by this analysis, some are given the designation of being

considered a Best-Buy, meaning the proposed action provides the greatest increase

in output for the least increases in cost. By default, the No Action alternative and

the largest cost effective alternative (i.e., the cost effective alternative with the

greatest annualized ecosystem outputs or benefits) are considered to be Best Buy

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alternatives. Any of the proposed actions that are found to be cost-effective during

this analysis may be considered for selection as the TSP and ultimately the

Recommended Plan. The information utilized by the software is listed in

Table 3.12. However, according to guidance from ER 1105-2-100, E-41 c., rarely will

the NER plan not be among the best buy plans. The reason for such a selection

should be clearly explained in the supporting documentation as well as the potential

implications for cost sharing. The background information utilized for the CE/ICA

analysis is found in Appendix K.

Table 3.12. Alternatives Costs and Benefits

Alternative Acres of

Benefit AAHUs

Total

Construction

Cost

Annualized

Cost**

Annualized

Cost/AAHU

35* 820 334 $1,090,000 $61,000 $180

38* 2,422 1,013 $4,550,000 $236,000 $230

37 2,279 922 $4,210,000 $217,000 $240

39* 3,881 1,602 $7,700,000 $394,000 $250

36 3,061 1,268 $6,870,000 $351,000 $280

33 1,602 679 $3,780,000 $197,000 $290

34 1,459 589 $3,360,000 $174,000 $300

* Denotes Best Buy Plan

**Average annual costs were determined over the six-year construction period with a discount rate of

4.375 percent. Costs represent preliminary costs for planning purposes only and do not represent a

fully funded cost estimate.

The results of the IWR Planning Suite analysis are found in Table 3.13 and

Figures 3.25 and 3.26. According to the analysis, all proposed actions were found to

be cost-effective. Three actions plus the No-Action were also designated as Best

Buys. Based on the results of the IWR Planning Suite analysis, it was determined

that all of the proposed actions within the final array of alternatives could be

considered for selection as the TSP and that no alternatives were eliminated from

consideration. The justification for the selection of the TSP/ Recommended Plan is

provided in Section 3.7.11.1.

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Table 3.13. IWR-PLAN Results

Alternative Annualized

Cost

Output

(AAHUs)

Cost

Effective?

No Action Plan $0 0 Best Buy

35 $61,000 334 Best Buy

34 $174,000 589 Yes

33 $197,000 679 Yes

37 $217,000 922 Yes

38 $236,000 1013 Best Buy

36 $351,000 1268 Yes

39 $394,000 1602 Best Buy

Figure 3.25. Cost versus Output

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Figure 3.26. IWR Best Buy Comparison

3.5.4 Summary Comparison of Final Array of Alternatives

The conversion of acreages to freshwater marsh and open water for the final array,

as previously depicted in Figure 2.2, is summarized in Table 3.14. In addition, a

summary comparison of impacts to significant resources for the final array of

alternatives is found in Table 3.15. The information presented in both tables, along

with each plan’s contribution to planning objectives, constraints, and evaluation

criteria was used when selecting the National Ecosystem Restoration (NER) plan,

along with the Recommended Plan. Table 3.15 represents a summary of the costs,

impacts, and quantities associated with the final array of alternatives. Further

information regarding these proposed actions and the corresponding impacts may

be found throughout Sections 4 and 5 of this report.

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Table 3.14. Conversion of Habitat Types (Years to Marsh)

for each Alternative

Years to Marsh Study Area Degradation (Acres) Benefits Achieved fr om Final Ar r ay (Acres)

No-Action 33 34 35 36 37 38 39

Existing Marsh 300 144 146 0 290 146 144 290

10 Years to Marsh 1,723 241 775 0 1,016 775 241 1,016

20 - 3- Years to Marsh 7,979 975 299 542 1,274 841 1,518 1,816

30 - 50 Years to Marsh 8,202 242 239 278 481 517 519 759

Total Acres 18,204 1,602 1,459 820 3,061 2,279 2,422 3,881

*Benefits (AAHUs) 0 679 589 334 1,268 922 1,013 1,602

* AAHUs calculated for year 50 (2061)

3.6 NATIONAL ECOSYSTEM RESTORATION PLAN

The following is the criteria for selecting the NER Plan.

For ecosystem restoration projects, a plan that reasonably maximizes ecosystem

restoration benefits compared to costs, consistent with the Federal objective, shall be

selected. The selected plan must be shown to be cost-effective and justified to achieve

the desired level of output. This plan shall be identified as the National Ecosystem

Restoration (NER) Plan (ER 1105-2-100).

Based on the results of the WVA modeling, the IWR Planning Suite analysis, and

the impacts of alternative plans, Alternative 39 was chosen to be the NER plan.

This plan includes all the areas in the final array including the areas with the

critical need of restoration (NE-2 and SE-2 have already begun converting to

marsh) and additional areas that are expected to need restoration in the next 20

years (SE-1, NE-1). The non-Federal sponsor supports Alternative 39 as the NER plan

and believes it represents the long term restoration need for the area. The non-Federal

sponsor supports the NER plan; therefore, no separate locally preferred plan (LPP) is

identified. The NER plan is also identified as the environmentally preferable plan

(EPP) since it maximizes the environmental benefit

3.7 PLAN SELECTION – TENTATIVELY SELECTED PLAN (TSP)/

RECOMMENDED PLAN

The following is the criteria for selection of the TSP and Recommended Plan.

A single alternative plan would be selected for recommendation from among all those

that have been considered. It must be shown to be preferable to taking no action (if

the No-action alternative is not recommended) or implementing any of the other

alternatives considered during the planning process (ER 1105-2-100).

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Alternative 33, which addresses the most-highly degraded portion of the study area

(NE-2) and provides benefits within NE-1, was chosen as the TSP and was later

confirmed as the Recommended Plan. Alternative 33 was chosen based on the WVA

modeling results (Tables 3.11 and 3.12), IWR Planning Suite analysis (Table 3.13

and Figures 3.17 and 3.18), and the impacts on significant resources found within

the study area (Table 3.15). Alternative 33 is an implementable increment of the

NER plan, is within the cost and scope of the WRDA 2007 authorization, has standalone utility, and can be justified based on ecosystem restoration benefits. This

alternative provides sustainable benefits for the areas of impact with 679 AAHUs.

The non-Federal sponsor supports Alternative 33 as the Recommended Plan under

the current WRDA 2007 authorization.

A comparison of the NER and the Recommended Plan is shown in Figure 3.27.

Development of additional restoration activities within the most highly-degraded

areas not currently evaluated as part of the Recommended Plan (Alternative 33)

should receive priority. More specifically, primary consideration should be given to

improving degradation within SE-2, then SE-1. It should be noted that there are

other potential sources for restoration within the study area that may be able to

provide an opportunity to build the remaining portions of the NER plan and/or build

additional restoration features above the Recommended Plan. The Livingston

Parish CIAP project, Hydrologic Restoration in Swamps West of Lake Maurepas,

located within the study area received study funding in September 2010 to begin

design but has not yet been awarded construction funding. Based on the

aforementioned coordination, once the CIAP project is authorized for construction

funding, the actions proposed by this project will represent a separate effort from

the actions recommended by the LCA ARDC Modification project. To date, no

formal request for the use of CIAP funds as a cost share for this project has been

made.

A comparison of the costs for the NER plan and the Recommended Plan is shown in

Table 3.16. Additionally, the details behind the authorized costs are located in

Table 3.17.

3.7.1 Components

Features of the Recommended Plan (Figure 3.4) include:

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

channel in the north bank of the ARDC also extending through the railroad

grade into NE-1 to add connectivity between NE-1, NE-2, and the ARDC.

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Table 3.15. Summary Comparison of Final Array of Alternatives

No-Action

Alternative 33

(Recommended

Plan)

Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

1. PLAN DESCRIPTION No-Action/Without Project Condition

NE-2, NE-1, 3 cutsARDC dredgedmaterial berm, 1railroad grade cut, 1conveyance channelcut, vegetativeplantings

SE-2, SE-1, 1 cut

ARDC dredgedmaterial berm, 2railroad grade cuts, 1conveyance channelcut, vegetativeplantings

SE-1, 1 cut ARDCdredged material berm

NE-2, SE-2, NE-1, SE1, 4 cuts ARDCdredged materialberm, 3 railroad gradecuts, 2 conveyancechannel cuts,vegetative plantings

SE-2, SE-1, 2 cutsARDC dredgedmaterial berm, 2

railroad grade cuts, 1conveyance channelcut, vegetativeplantings

NE-2. SE-1, NE-1, 4cuts ARDC dredgedmaterial berm, 1railroad grade cut, 1conveyance channelcut, vegetativeplantings

NE-2, SE-2, NE-1, SE-1, 5cuts ARDC, dredged materialberm, 3 railroad grade cuts, 2conveyance channel cuts,vegetative plantings

2. IMPACT ASSESSMENT

A. NER1) Total Project Cost:preliminary cost- planning only $0 $3,780,000 $3,370,000 $1,090,000 $6,870,000 $4,210,000 $4,550,000 $7,700,0002) Annual Cost (not fullyfunded) $0 $196,686 $173,671 $60,956 $351,365 $217,220 $236,293 $394,1713) Total Benefits (CHU) 0 33,937 29,429 16,680 63,402 46,109 50,653 80,0824) Annual Net Benefits(AAHU) 0 679 589 334 1,268 922 1,013 1,6025) Cost Effective (yes/no/bestbuy) Best Buy Yes Yes Best Buy Yes Yes Best Buy Best BuyB. EnvironmentalResources1) Soils and Water Bottoms:Soils

Conversion of 18,204 acres ofBarbary, Fausse, andMaurepas swamp soilsexperience nearly continuouswaterlogging, subsidence and

reduction in organiccomponents.

Net total of 1,602acres of wetland soilsrestored andnourished; 2.6 acresARDC berm soils and28.6 acres existingswamp soils removedto constructbottomland hardwood"islands."

Net total of 1,459acres of wetland soilsrestored andnourished; 3.4 acresARDC berm soils and15.4 acres existingswamp soils removedto constructbottomland hardwood"islands."

Net total of 820 acresof wetland soilsrestored andnourished; 2.4 acresARDC berm soils and10.9 acres existingswamp soils removedto constructbottomland hardwood"islands."

Net total of 3,061acres of wetland soilsrestored andnourished; 6.0 acresARDC berm soils and44.0 acres existingswamp soils removedto constructbottomland hardwood"islands."

Net total of 2,279acres of wetland soilsrestored andnourished; 5.8 acresARDC berm soils and26.3 acres existingswamp soils removedto constructbottomland hardwood"islands."

Net total of 2,422acres of wetland soilsrestored andnourished; 5.0 acresARDC berm soils and39.5 acres existingswamp soils removedto constructbottomland hardwood"islands."

Net total of 3,881 acres ofwetland soils restored andnourished; 8.4 acresARDC berm soils and 54.9acres existing swamp soilsremoved to constructbottomland hardwood"islands."

2) Soils and Water Bottoms:Water Bottoms

Swamp water bottoms remainisolated from hydrologicconnections; swamp waterbottoms convert to open water;decreased nutrients anddetritus from decomposingswamp vegetation

18.6 acres existingswamp water bottomsdredged to createdrainage channels;increased hydrologicconnections and treeplantings result inincreased detritus andhealthier benthicsubstrates.

10.5 acres existingswamp water bottomsdredged to createdrainage channels;increased hydrologicconnections and treeplantings result inincreased detritus andhealthier benthicsubstrates

7.2 acres existingswamp water bottomsdredged to createdrainage channels;increased hydrologicconnections result inincreased detritus andhealthier benthicsubstrates

29.1 acres existingswamp water bottomsdredged to createdrainage channels;increased hydrologicconnections and treeplantings result inincreased detritus andhealthier benthicsubstrates

17.7 acres existingswamp water bottomsdredged to createdrainage channels;increased hydrologicconnections and treeplantings result inincreased detritus andhealthier benthicsubstrates

25.8 acres existingswamp water bottomsdredged to createdrainage channels;increased hydrologicconnections and treeplantings result inincreased detritus andhealthier benthicsubstrates

36.3 acres existing swampwater bottoms dredged tocreate drainage channels;increased hydrologicconnections and treeplantings result in increaseddetritus and healthier benthicsubstrates

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Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

3) Hydrology: Flow andWater Levels

Continued hydrologic isolationand impoundment resulting inreduced flows into and out ofthe SA; water levels static butsteadily increase due tocontinued hydrologic barriersand projected sea level rise.

Connected hydrologyincreases flows intoand out of 1,602 acresswamp; water levelsfluctuate in responseto ARDC and sea levelrises.

Connected hydrologyincreases flows intoand out of 1,459 acresswamp; water levelsfluctuate in responseto ARDC and sea levelrises.

Connected hydrologyincreases flows intoand out of 820 acresswamp; water levelsfluctuate in responseto ARDC and sea levelrises.

Connected hydrologyincreases flows intoand out of 3,061 acresswamp; water levelsfluctuate in responseto ARDC and sea levelrises.

Connected hydrologyincreases flows intoand out of 2,279 acresswamp; water levelsfluctuate in responseto ARDC and sea levelrises.

Connected hydrologyincreases flows intoand out of 2,422 acresswamp; water levelsfluctuate in responseto ARDC and sea levelrises.

Connected hydrologyincreases flows into and out of3,881 acres swamp; waterlevels fluctuate in response toARDC and sea level rises.

4) Hydrology: Sediment

Continued lack of sedimentinputs into SA due tohydrologic isolation andimpoundment.

Connected hydrologyincreases potential forsediment inputs into1,602 acres swamp.

Connected hydrologyincreases potential forsediment inputs into1,459 acres swamp.

Connected hydrologyincreases potential forsediment inputs into820 acres swamp.

Connected hydrologyincreases potential forsediment inputs into3,061 acres swamp.

Connected hydrologyincreases potential forsediment inputs into2,279 acres swamp.

Connected hydrologyincreases potential forsediment inputs into2,422 acres swamp.

Connected hydrologyincreases potential forsediment inputs into 3,881acres

5) Hydrology: Water Use andSupply

Continued increase in wateruse and supply demands;conversion of swamp habitat toopen water reduces waterpurification function ofwetlands.

Continued increase inwater use and supplydemands; connectedhydrology improveswater purificationfunction over 1,602acres swamp.

Continued increase inwater use and supplydemands; connectedhydrology improveswater purificationfunction over 1,459acres swamp.

Continued increase inwater use and supplydemands; connectedhydrology improveswater purificationfunction over 820acres swamp.

Continued increase inwater use and supplydemands; connectedhydrology improveswater purificationfunction over 3,061acres swamp.

Continued increase inwater use and supplydemands; connectedhydrology improveswater purificationfunction over 2,279acres swamp.

Continued increase inwater use and supplydemands; connectedhydrology improveswater purificationfunction over 2,422acres swamp.

Continued increase in wateruse and supply demands;connected hydrology improveswater purification functionover 3,881 acres swamp.

6) Hydrology: Groundwater

Nearby human populations andindustry continue to increaseresulting in increasedgroundwater demands anddecreased groundwaterresources. Continuallydegrading swamp habitat nolonger functions as an effectivenatural water quality filtrationsystem to shallow aquifers.

Restoration of 1,602acres swamp acts asnatural water qualityfiltration system to theshallow aquifers.

Restoration of 1,459acres swamp acts asnatural water qualityfiltration system to theshallow aquifers.

Restoration of 820acres swamp acts asnatural water qualityfiltration system to theshallow aquifers.

Restoration of 3,061swamp acts as naturalwater quality filtrationsystem to the shallowaquifers.

Restoration of 2,279acres swamp acts asnatural water qualityfiltration system to theshallow aquifers.

Restoration of 2,422acres swamp acts asnatural water qualityfiltration system to theshallow aquifers.

Restoration of 3,881 acresswamp acts as natural waterquality filtration system tothe shallow aquifers.

7) Water Quality

Conversion of 18,204 acres ofswamp vegetation to freshmarsh and open water reducesnatural water quality.Continued discharge ofuntreated stormwater runofffrom nearby populated areasinto the SA.

Temporary negativeimpacts (e.g.,increased turbidity,decreased dissolvedoxygen) duringconstruction. Waterquality improves over1,602 acres of swamphabitat due toincreased connectivityas well as absorptionand filtering of theuntreated stormwaterrunoff.

Temporary negative

impacts (e.g.,increased turbidity,decreased dissolvedoxygen) duringconstruction. Waterquality improves over1,459 acres of swamphabitat due toincreased connectivityas well as absorptionand filtering of theuntreated stormwaterrunoff.

Temporary negativeimpacts (e.g.,increased turbidity,decreased dissolvedoxygen) duringconstruction. Waterquality improves over820 acres of swamphabitat due toincreased connectivityas well as absorptionand filtering of theuntreated stormwaterrunoff.

Temporary negativeimpacts (e.g.,increased turbidity,decreased dissolvedoxygen) duringconstruction. Waterquality improves over3,061 acres of swamphabitat due toincreased connectivityas well as absorptionand filtering of theuntreated stormwaterrunoff.

Temporary negativeimpacts (e.g.,increased turbidity,decreased dissolvedoxygen) duringconstruction. Waterquality improves over2,279 acres of swamphabitat due toincreased connectivityas well as absorptionand filtering of theuntreated stormwaterrunoff.

Temporary negativeimpacts (e.g.,increased turbidity,decreased dissolvedoxygen) duringconstruction. Waterquality improves over2,422 acres of swamphabitat due toincreased connectivityas well as absorptionand filtering of theuntreated stormwaterrunoff.

Temporary negative impacts

(e.g., increased turbidity,decreased dissolved oxygen)during construction. Waterquality improves over 3,881acres of swamp habitat due toincreased connectivity as wellas absorption and filtering ofthe untreated stormwaterrunoff.

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Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

8) Water Quality: Salinity

Continued impoundmentresults in longer residence timeof higher-salinity water. Thisresults in absorption of salinityinto swamp soils, continuingthe degradation of freshwaterswamp and bottomlandhardwood vegetation. Salinitiesmay also increase due toprojected relative sea level rise.

Restored hydrologicconnectivity to 1,602acres reducesimpoundment ofhigher salinity waters;salinities would havetemporary spikes, butflushing would lowersalinity overall. At thesame time, salinitiesmay also increase dueto projected relativesea level rise.

Restored hydrologicconnectivity to 1,459acres reducesimpoundment ofhigher salinity waters;salinities would havetemporary spikes, butflushing would lowersalinity overall. At thesame time, salinitiesmay also increase dueto projected relativesea level rise.

Restored hydrologicconnectivity to 820acres reducesimpoundment ofhigher salinity waters;salinities would havetemporary spikes, butflushing would lowersalinity overall. At thesame time, salinitiesmay also increase dueto projected relativesea level rise.

Restored hydrologicconnectivity to 3,061acres reducesimpoundment ofhigher salinity waters;salinities would havetemporary spikes, butflushing would lowersalinity overall. At thesame time, salinitiesmay also increase dueto projected relativesea level rise.

Restored hydrologicconnectivity to 2,279acres reducesimpoundment ofhigher salinity waters;salinities would havetemporary spikes, butflushing would lowersalinity overall. At thesame time, salinitiesmay also increase dueto projected relativesea level rise.

Restored hydrologicconnectivity to 2,422acres reducesimpoundment ofhigher salinity waters;salinities would havetemporary spikes, butflushing would lowersalinity overall. At thesame time, salinitiesmay also increase dueto projected relativesea level rise.

Restored hydrologicconnectivity to 3,881 acresreduces impoundment ofhigher salinity waters;salinities would havetemporary spikes, butflushing would lower salinityoverall. At the same time,salinities may also increasedue to projected relative sealevel rise.

9) Air Quality

Conversion of 18,204 acres ofswamp vegetation to freshmarsh and open water habitatover 50- year period of analysisreduces function of swampvegetation to act as naturalfilter for air pollutants.

Restoration of 1,602acres of freshwaterswamp/bottomlandhardwood habitat mayact as natural filtersfor air pollutants.

Restoration of 1,459acres of freshwaterswamp/bottomlandhardwood habitat mayact as natural filtersfor air pollutants.

Restoration of 820acres of freshwaterswamp/bottomlandhardwood habitat mayact as natural filtersfor air pollutants.

Restoration of 3,061acres of freshwaterswamp/bottomlandhardwood habitat mayact as natural filtersfor air pollutants.

Restoration of 2,279acres of freshwaterswamp/bottomlandhardwood habitat mayact as natural filtersfor air pollutants.

Restoration of 2,422acres of freshwaterswamp/bottomlandhardwood habitat mayact as natural filtersfor air pollutants.

Restoration of 3,881 acres offreshwaterswamp/bottomland hardwoodhabitat may act as naturalfilters for air pollutants.

10) Noise

Increased human activitieswithin the study area mayincrease noise levels.

Short term, localizedand temporaryincreased noise due toconstruction. Longterm, impacts similarto No-ActionAlternative.

Short term, localizedand temporaryincreased noise due toconstruction. Longterm, impacts similarto No-ActionAlternative.

Short term, localizedand temporaryincreased noise due toconstruction. Longterm, impacts similarto No-ActionAlternative.

Short term, localizedand temporaryincreased noise due toconstruction. Longterm, impacts similarto No-ActionAlternative.

Short term, localizedand temporaryincreased noise due toconstruction. Longterm, impacts similarto No-ActionAlternative.

Short term, localizedand temporaryincreased noise due toconstruction. Longterm, impacts similarto No-ActionAlternative.

Short term, localized andtemporary increased noisedue to construction. Longterm, impacts similar to NoAction Alternative.

11) Vegetation Resources:Riparian Vegetation

Degradation of riparianvegetation would continue asswamp converts to open water.

There would becreation of riparianhabitat along newconveyance channels.Riparian vegetation ondredged materialberms impacted byconstruction.

There would becreation of riparianhabitat along newconveyance channels.Riparian vegetation ondredged materialberms impacted byconstruction.

There would becreation of riparianhabitat along newconveyance channels.Riparian vegetation ondredged materialberms impacted byconstruction.

There would becreation of riparianhabitat along newconveyance channels.Riparian vegetation ondredged materialberms impacted byconstruction.

There would becreation of riparianhabitat along newconveyance channels.Riparian vegetation ondredged materialberms impacted byconstruction.

There would becreation of riparianhabitat along newconveyance channels.Riparian vegetation ondredged materialberms impacted byconstruction.

There would be creation ofriparian habitat along newconveyance channels.Riparian vegetation ondredged material bermsimpacted by construction.

12) Vegetation Resources:Wetland Vegetation

Degradation of wetlandvegetation would continue withconversion of 18,204 acres ofexisting swamp to fresh marshand open water over 50-yearperiod of analysis.

A net total of 1,602acres of baldcypresstupelo swamp habitathydrologicallyrestored.

A net total of 1,459acres of baldcypresstupelo swamp habitathydrologicallyrestored.

A net total of 820 acresof baldcypress-tupeloswamp habitathydrologicallyrestored.

A net total of 3,061acres of baldcypresstupelo swamp habitathydrologicallyrestored.

A net total of 2,279acres of baldcypresstupelo swamp habitathydrologicallyrestored.

A net total of 2,422acres of baldcypresstupelo swamp habitathydrologicallyrestored.

A net total of 3,881 acres ofbaldcypress-tupelo swamphabitat hydrologicallyrestored.

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Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

13) Vegetation Resources:Upland Vegetation

Upland vegetation along ARDCberms likely unchanged over50-year period of analysis

Upland vegetation onARDC bermsconverted toconveyance channel.

Upland vegetation onARDC bermsconverted toconveyance channel.

Upland vegetation onARDC bermsconverted toconveyance channel.

Upland vegetation onARDC bermsconverted toconveyance channel.

Upland vegetation on

ARDC bermsconverted toconveyance channel.

Upland vegetation onARDC bermsconverted toconveyance channel.

Upland vegetation on ARDCberms converted toconveyance channel.

14) Vegetation Resources:Submerged AquaticVegetation (SAV)

Presently there is little to nohabitat for SAV due to invasivespecies out-competing them.

This would likely stayunchanged over 50-year periodof analysis.

Creation of 18.6 acresof conveyancechannels would createa healthy habitat forSAV.

Creation of 10.5 acresof conveyancechannels would createa healthy habitat forSAV.

Creation of 7.2 acres ofconveyance channelswould create a healthyhabitat for SAV.

Creation of 29.1 acresof conveyancechannels would createa healthy habitat forSAV.

Creation of 17.7 acresof conveyancechannels would createa healthy habitat forSAV.

Creation of 25.8 acresof conveyancechannels would createa healthy habitat forSAV.

Creation of 36.3 acres ofconveyance channels wouldcreate a healthy habitat forSAV.

15) Vegetation Resources:Invasive Species

Invasive species would continueto spread throughout the studyarea.

Reconnectinghydrology to 1,602acres of swamp makesconditions conducivefor invasive species tocontinue spreading.

Reconnectinghydrology to 1,459acres of swamp makesconditions conducivefor invasive species tocontinue spreading.

Reconnectinghydrology to 820 acresof swamp makesconditions conducivefor invasive species tocontinue spreading.

Reconnectinghydrology to 3,061acres of swamp makesconditions conducivefor invasive species tocontinue spreading.

Reconnectinghydrology to 2,279acres of swamp makesconditions conducivefor invasive species tocontinue spreading.

Reconnectinghydrology to 2,422acres of swamp makesconditions conducivefor invasive species tocontinue spreading.

Reconnecting hydrology to3,881 acres of swamp makesconditions conducive forinvasive species to continuespreading.

16) Wildlife Resources

Continued conversion of 18,204acres of bottomland swamp tofresh marsh and open waterhabitat.

Connected hydrologyimproves 1,602 acresof swamp habitat forwildlife use.

Connected hydrologyimproves 1,459 acresof swamp habitat forwildlife use.

Connected hydrologyimproves 820 acres ofswamp habitat forwildlife use.

Connected hydrologyimproves 3,061 acresof swamp habitat forwildlife use.

Connected hydrologyimproves 2,279 acresof swamp habitat forwildlife use.

Connected hydrologyimproves 2,422 acresof swamp habitat forwildlife use.

Connected hydrologyimproves 3,881 acres ofswamp habitat for wildlifeuse.

17) Fishery Resources

Conversion of 18,204 acres ofswamp vegetation to freshmarsh and open water habitatincreases availability of openwater habitat for fish andaquatic organisms. However,ARDC berms limit access;water quality decline makesenvironment suitable only forthose aquatic organismstolerant of low dissolved oxygenconditions.

Connected hydrologyallows commercial andrecreational fisheryuse in 1,602 acres ofimproved swamphabitat.

Connected hydrologyallows commercial andrecreational fisheryuse in 1,459 acres ofimproved swamphabitat.

Connected hydrologyallows commercial andrecreational fisheryuse in 820 acres ofimproved swamphabitat.

Connected hydrologyallows commercial andrecreational fisheryuse in 3,061 acres ofimproved swamphabitat.

Connected hydrologyallows commercial andrecreational fisheryuse in 2,279 acres ofimproved swamphabitat.

Connected hydrologyallows commercial andrecreational fisheryuse in 2,422 acres ofimproved swamphabitat.

Connected hydrology allowscommercial and recreationalfishery use in 3,881 acres ofimproved swamp habitat.

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Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

19) Aquatic Resources:Plankton

Plankton resources would notbe able to filter nutrients fromthe watershed due to the lack ofconnectivity.

There would betemporary andlocalized impacts (e.g.,decreased dissolvedoxygen, increasedturbidity) to planktoncommunities duringconstruction. Longterm, creation ofconveyance channelsin concert with marshcreation andnourishment wouldresult in greaterproductivity.

There would betemporary andlocalized impacts (e.g.,decreased dissolvedoxygen, increasedturbidity) to planktoncommunities duringconstruction. Longterm, creation ofconveyance channelsin concert with marshcreation andnourishment wouldresult in greaterproductivity.

There would betemporary andlocalized impacts (e.g.,decreased dissolvedoxygen, increasedturbidity) to planktoncommunities duringconstruction. Longterm, creation ofconveyance channelsin concert with marshcreation andnourishment wouldresult in greaterproductivity.

There would betemporary andlocalized impacts (e.g.,decreased dissolvedoxygen, increasedturbidity) to planktoncommunities duringconstruction. Longterm, creation ofconveyance channelsin concert with marshcreation andnourishment wouldresult in greaterproductivity.

There would betemporary andlocalized impacts (e.g.,decreased dissolvedoxygen, increasedturbidity) to planktoncommunities duringconstruction. Longterm, creation ofconveyance channelsin concert with marshcreation andnourishment wouldresult in greaterproductivity.

There would betemporary andlocalized impacts (e.g.,decreased dissolvedoxygen, increasedturbidity) to planktoncommunities duringconstruction. Longterm, creation ofconveyance channelsin concert with marshcreation andnourishment wouldresult in greaterproductivity.

There would be temporaryand localized impacts (e.g.,decreased dissolved oxygen,increased turbidity) toplankton communities duringconstruction. Long term,creation of conveyancechannels in concert withmarsh creation andnourishment would result ingreater productivity.

20) Aquatic Resources:Benthic

The amount of habitatavailable for benthosassemblages that utilize swampor marsh edge habitats wouldlikely decrease. Theavailability of nutrients anddetritus from the decomposingswamp vegetation wouldinitially increase and thendecrease, causing the decline inhabitat availability.

Wetland restorationand reconnectinghydrology of 1,602acres would result in agreater export ofdissolved organiccompounds anddetritus from thewetlands creating ahealthier benthichabitat.

Wetland restorationand reconnectinghydrology of1,459acres wouldresult in a greaterexport of dissolvedorganic compoundsand detritus from thewetlands creating ahealthier benthichabitat.

Wetland restorationand reconnectinghydrology of 822 acreswould result in agreater export ofdissolved organiccompounds anddetritus from thewetlands creating ahealthier benthichabitat.

Wetland restorationand reconnectinghydrology of 3,061acres would result in agreater export ofdissolved organiccompounds anddetritus from thewetlands creating ahealthier benthichabitat.

Wetland restorationand reconnectinghydrology of 2,279acres would result in agreater export ofdissolved organiccompounds anddetritus from thewetlands creating ahealthier benthichabitat.

Wetland restorationand reconnectinghydrology of 2,422acres would result in agreater export ofdissolved organiccompounds anddetritus from thewetlands creating ahealthier benthichabitat.

Wetland restoration andreconnecting hydrology of3,881 acres would result in agreater export of dissolvedorganic compounds anddetritus from the wetlandscreating a healthier benthichabitat.

21) Essential Fish andHabitat (EFH)

No EFH identified within SA.This designation would likelynot change over the 50-yearperiod of analysis.

Proposed action wouldnot likely result inchanges to EFH.

Proposed action wouldnot likely result inchanges to EFH.

Proposed action wouldnot likely result inchanges to EFH.

Proposed action wouldnot likely result inchanges to EFH.

Proposed action wouldnot likely result inchanges to EFH.

Proposed action wouldnot likely result inchanges to EFH.

Proposed action would notlikely result in changes toEFH.

22) Threatened andEndangered Species

Converted 18,204 acres ofswamp habitat to fresh marshand open water habitats wouldlikely not be utilized by listedspecies.

Restored 1,602 acres ofMaurepas Swampwould likely not beutilized by listedspecies.

Restored 1,459 acres ofMaurepas Swampwould likely not beutilized by listedspecies.

Restored 820 acres ofMaurepas Swampwould likely not beutilized by listedspecies.

Restored 3,061 acres ofMaurepas Swampwould likely not beutilized by listedspecies.

Restored 2,279 acres ofMaurepas Swampwould likely not beutilized by listedspecies.

Restored 2,422 acres ofMaurepas Swampwould likely not beutilized by listedspecies.

Restored 3,881 acres ofMaurepas Swamp wouldlikely not be utilized by listedspecies.

23) Cultural and HistoricResources

The land loss within the studyarea threatens the integrity ofthese resources.

Ecosystem restorationwould prevent furtherland loss and havepositive effects onthese resources.

Ecosystem restorationwould prevent furtherland loss and havepositive effects onthese resources.

Ecosystem restorationwould prevent furtherland loss and havepositive effects onthese resources.

Ecosystem restorationwould prevent furtherland loss and havepositive effects onthese resources.

Ecosystem restorationwould prevent furtherland loss and havepositive effects onthese resources.

Ecosystem restorationwould prevent furtherland loss and havepositive effects onthese resources.

Ecosystem restoration wouldprevent further land loss andhave positive effects on theseresources.

24) Aesthetics

Conversion of 18,204 acres ofswamp vegetation to freshmarsh or open water habitatcould reduce aesthetics.

Restoration of 1,602acres of bottomlandswamp would improveaesthetics.

Restoration of 1,459acres of bottomlandswamp would improveaesthetics.

Restoration of 820acres of bottomlandswamp would improveaesthetics.

Restoration of 3,061acres of bottomlandswamp would improveaesthetics.

Restoration of 2,279acres of bottomlandswamp would improveaesthetics.

Restoration of 2,422acres of bottomlandswamp would improveaesthetics.

Restoration of 3,881 acres ofbottomland swamp wouldimprove aesthetics.

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Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

25) Recreational Resources

Support and sustainability ofbottomland swamp recreationalopportunities would declineover time with conversion to anopen water system.

The proposed actionwould lead toimprovements inswamp habitat,resulting in a highernumber of recreationalopportunities.

The proposed actionwould lead toimprovements inswamp habitat,resulting in a highernumber of recreationalopportunities.

The proposed actionwould lead toimprovements inswamp habitat,resulting in a highernumber of recreationalopportunities.

The proposed actionwould lead toimprovements inswamp habitat,resulting in a highernumber of recreationalopportunities.

The proposed actionwould lead toimprovements inswamp habitat,resulting in a highernumber of recreationalopportunities.

The proposed actionwould lead toimprovements inswamp habitat,resulting in a highernumber of recreationalopportunities.

The proposed action wouldlead to improvements inswamp habitat, resulting in ahigher number of recreationalopportunities.

26) Socioeconomic andHuman Resources:Population and Housing

No impacts to population andhousing would occur.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

27) Socioeconomic andHuman Resources:Employment and Income

The employment and income ofthe residents would followregional trends. Presently, closeto 35% of the 477 study arearesidents are retired, and theunemployment rate is 7.2% inthe parish.

Minor positive effectsin temporary andpermanent laborwould occur as a resultof ecosystemrestoration.

Minor positive effectsin temporary andpermanent laborwould occur as a resultof ecosystemrestoration

Minor positive effectsin temporary andpermanent laborwould occur as a resultof ecosystemrestoration

Minor positive effectsin temporary andpermanent laborwould occur as a resultof ecosystemrestoration

Minor positive effectsin temporary andpermanent laborwould occur as a resultof ecosystemrestoration

Minor positive effectsin temporary andpermanent laborwould occur as a resultof ecosystemrestoration

Minor positive effects intemporary and permanentlabor would occur as a resultof ecosystem restoration

28) Socioeconomic andHuman Resources:Community Cohesion

Several of the currentsubdivisions would expand.A proposed bridge over theARDC would improvecommunity cohesion.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

29) Socioeconomics andHuman Resources:Environmental Justice

No disproportionate impacts onminority and/or low-incomecommunities would occur.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

30) Socioeconomic andHuman Resources:Infrastructure

Conversion of 18,204 acres ofswamp vegetation to freshmarsh or open water habitatmay affect relocations andmaintenance of infrastructurewithin the study area.

Restoration couldprovide protection byreducing inundation,wave action, anderosion.

Restoration couldprovide protection byreducing inundation,wave action, anderosion.

Restoration couldprovide protection byreducing inundation,wave action, anderosion.

Restoration couldprovide protection byreducing inundation,wave action, anderosion.

Restoration couldprovide protection byreducing inundation,wave action, anderosion.

Restoration couldprovide protection byreducing inundation,wave action, anderosion.

Restoration could provideprotection by reducinginundation, wave action, anderosion.

31) Socioeconomic andHuman Resources: Businessand Industry

Wetland land loss potentiallythreatens businesses in thestudy area.

Improvements andnourishment of swamphabitat would sustainbusiness and industry.

Improvements andnourishment of swamphabitat would sustainbusiness and industry.

Improvements andnourishment of swamphabitat would sustainbusiness and industry.

Improvements andnourishment of swamphabitat would sustainbusiness and industry.

Improvements andnourishment of swamphabitat would sustainbusiness and industry.

Improvements andnourishment of swamphabitat would sustainbusiness and industry.

Improvements andnourishment of swamphabitat would sustainbusiness and industry.

32) Socioeconomic andHuman Resources: Trafficand Transportation

Wetland land loss threatens thestability of roads passingthrough area, resulting inincreased maintenance. Severalof the current subdivisionswould expand, creatingadditional roads, bridges, andtraffic.

This alternative wouldreduce the amount ofroad damages andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofroad damages andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofroad damages andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofroad damages andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofroad damages andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofroad damages andrelocations neededcompared to the noaction alternative.

This alternative would reducethe amount of road damagesand relocations neededcompared to the no-actionalternative.

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Alternative 33

(Recommended

Plan)

Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

33) Socioeconomic andHuman Resources: PublicFacilities and Services

Wetland land loss threatenspublic facilities and servicesand increases maintenance.Several of the currentsubdivisions would expand,creating additional needs forpublic facilities and services.

This alternative wouldreduce the amount ofmaintenance andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofmaintenance andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofmaintenance andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofmaintenance andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofmaintenance andrelocations neededcompared to the noaction alternative.

This alternative wouldreduce the amount ofmaintenance andrelocations neededcompared to the noaction alternative.

This alternative would reducethe amount of maintenanceand relocations neededcompared to the no-actionalternative.

34) Socioeconomic andHuman Resources: LocalGovernment Finances

Increasing population growthincreases local governmentfinances.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

35) Socioeconomic andHuman Resources: TaxRevenue and Property Values

Additional increases inproperty values and taxrevenues would be sustainedthrough the filling of lots in theexisting and proposedsubdivisions. At the same time,property values may drop fromlowering aesthetics due toswamp degradation.

Property values mayincrease withimproved aesthetics.

Property values mayincrease withimproved aesthetics.

Property values mayincrease withimproved aesthetics.

Property values mayincrease withimproved aesthetics.

Property values mayincrease withimproved aesthetics.

Property values mayincrease withimproved aesthetics.

Property values may increasewith improved aesthetics.

36) Socioeconomic andHuman Resources:Community and RegionalGrowth

Additional increases incommunity and regional growthwould be sustained through thefilling of lots in the existing andproposed subdivisions.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

37) Socioeconomic andHuman Resources: Land UseSocioeconomics – Agriculture

Agricultural lands, primarilylivestock pastures, wouldcontinue to be used.

There would be noimpacts to agricultureas a result of theproposed alternativeas there are noagricultural lands inthe area impacted bythis alternative.

There would be noimpacts to agricultureas a result of theproposed alternativeas there are noagricultural lands inthe area impacted bythis alternative.

There would be noimpacts to agricultureas a result of theproposed alternativeas there are noagricultural lands inthe area impacted bythis alternative.

There would be noimpacts to agricultureas a result of theproposed alternativeas there are noagricultural lands inthe area impacted bythis alternative.

There would be noimpacts to agricultureas a result of theproposed alternativeas there are noagricultural lands inthe area impacted bythis alternative.

There would be noimpacts to agricultureas a result of theproposed alternativeas there are noagricultural lands inthe area impacted bythis alternative.

There would be no impacts toagriculture as a result of theproposed alternative as thereare no agricultural lands inthe area impacted by thisalternative.

38) Socioeconomic andHuman Resources: Land UseSocioeconomics – Forestry

Little timber harvesting wouldtake place in the future due toa lack of quality timber.

There would berestoration easementsas a result of theproposed alternative,limiting forestryactivities.

There would berestoration easementsas a result of theproposed alternative,limiting forestryactivities.

There would berestoration easementsas a result of theproposed alternative,limiting forestryactivities.

There would berestoration easementsas a result of theproposed alternative,limiting forestryactivities.

There would berestoration easementsas a result of theproposed alternative,limiting forestryactivities.

There would berestoration easementsas a result of theproposed alternative,limiting forestryactivities.

There would be restorationeasements as a result of theproposed alternative, limitingforestry activities.

39) Socioeconomic andHuman Resources: Land UseSocioeconomics – Public

Lands

A portion of the MaurepasWMA is the only public landspresent in the study area.These lands may be adverselyaffected by future sea level rise.

Minor beneficialimpacts to public landsin study area.

Minor beneficialimpacts to public landsin study area.

Minor beneficialimpacts to public landsin study area.

Minor beneficialimpacts to public landsin study area.

Minor beneficialimpacts to public landsin study area.

Minor beneficialimpacts to public landsin study area.

Minor beneficial impacts topublic lands in study area.

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No-Action

Alternative 33

(Recommended

Plan)

Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

40) Socioeconomic andHuman Resources: WaterUse and Supply

There would continue to belittle significant public use ofsurface waters (other than forrecreation) in the study area.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

41) Socioeconomic andHuman Resources:Navigation

Blind River, ARDC, BayouManchac, and Amite River arelikely to continue to be usedprimarily for recreationalnavigation; continueddegradation could result inincreased maintenance issues.

Wetland restorationwould continue to giveprotection tonavigationalwaterways frommarine conditions.

Wetland restorationwould continue to giveprotection tonavigationalwaterways frommarine conditions.

Wetland restorationwould continue to giveprotection tonavigationalwaterways frommarine conditions.

Wetland restorationwould continue to giveprotection tonavigationalwaterways frommarine conditions.

Wetland restorationwould continue to giveprotection tonavigationalwaterways frommarine conditions.

Wetland restorationwould continue to giveprotection tonavigationalwaterways frommarine conditions.

Wetland restoration wouldcontinue to give protection tonavigational waterways frommarine conditions.

42) Socioeconomic andHuman Resources: ManMade Resources – Oil, Gas,and Utilities

Pipelines serving wells mayneed to be relocated and/or reburied due to the conversion of18,204 acres of swampvegetation to fresh marsh oropen water habitat.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction in relocations andre-burying needed comparedto the no-action alternative.

43) Socioeconomic andHuman Resources: ManMade Resources – Oil, Gas,and Utilities – Pipelines

Relocations and/or re-buryingof pipelines due to theconversion of 18,204 acres ofswamp vegetation to freshmarsh or open water habitatwould likely occur.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying needed

compared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying neededcompared to the noaction alternative.

Reduction inrelocations and reburying needed

compared to the noaction alternative.

Reduction in relocations andre-burying needed comparedto the no-action alternative.

44) Socioeconomic andHuman Resources: ManMade Resources – FloodControl and HurricaneProtection Levees

Continued degradation ofwetlands would result in anincrease in localized stormsurge and storm wavedamages. The Amite River andTributaries (AR&T) Federalflood control project is in thestudy area. Municipal andparish flood control measures,including drainage canals andcontrol structures, are presentin the study area.

There would be aminor decrease instorm surge and riskof flooding due tocoastal land retention.

There would be aminor decrease instorm surge and riskof flooding due tocoastal land retention.

There would be aminor decrease instorm surge and riskof flooding due tocoastal land retention.

There would be aminor decrease instorm surge and riskof flooding due tocoastal land retention.

There would be aminor decrease instorm surge and riskof flooding due tocoastal land retention.

There would be aminor decrease instorm surge and riskof flooding due tocoastal land retention.

There would be a minordecrease in storm surge andrisk of flooding due to coastalland retention.

45) Socioeconomic andHuman Resources: NaturalResources – CommercialFisheries

There are limited commercialfisheries present at this time.Production would not beaffected.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

46) Socioeconomic andHuman Resources: NaturalResources – Oyster Leases

SA provides no habitat suitablefor oysters or oyster leases.Unlikely oyster habitat orleases would develop over 50-year period of analysis.

Proposed action wouldprovide no habitatsuitable for oysters oroyster leases.

Proposed action wouldprovide no habitatsuitable for oysters oroyster leases.

Proposed action wouldprovide no habitatsuitable for oysters oroyster leases.

Proposed action wouldprovide no habitatsuitable for oysters oroyster leases.

Proposed action wouldprovide no habitatsuitable for oysters oroyster leases.

Proposed action wouldprovide no habitatsuitable for oysters oroyster leases.

Proposed action would provideno habitat suitable for oystersor oyster leases.

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No-Action

Alternative 33

(Recommended

Plan)

Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

47) HTRW

An HTRW Phase I ESA wasperformed and identified a lowprobability of encounteringcontaminants of concern.Increasing human populations,development, industry, andother activities in adjacentareas could increase potentialfor HTRW in SA.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative.

Impacts would besimilar to the NoAction Alternative. Impacts would be similar to the No-Action Alternative.

3. PlanEvaluation

A. Contribution toPlanning Objectives

1) Increase hydrologicconnectivity between thedegraded swamp andbottomland hardwoodhabitats and the ARDC byincreasing the exchange offreshwater, sediments, andnutrients over the 50-yearperiod of analysis.

0 222222 2

2) Reduce habitat conversionof swamp to open water overthe 50-year period ofanalysis.

0 222222 2

3) Facilitate naturalhydrologic cycles over the 50-year period of analysis byreducing impoundment indegraded swamp andbottomland hardwoodhabitats adjacent to theARDC to improve treeproductivity and seedlinggermination.

0 222222 2

4) Improve fish and wildlifehabitat over the 50-yearperiod of analysis.

0 222222 2

0=Does not meet1=Partially meets2=Meets

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No-Action

Alternative 33

(Recommended

Plan)

Alternative 34 Alternative 35 Alternative 36 Alternative 37 Alternative 38 Alternative 39

B. Planning Constraints1) Flood control 2 2 2 2 2 2 2 22) Designated Scenic Rivers 2 2 2 2 2 2 2 23) Hydroperiod 0 222222 2C. Response to EvaluationCriteria1) Completeness 0 2 2 2 2 2 2 22) Effectiveness 0 222222 23) Efficiency 0 2 2 2 2 2 2 24) Acceptability 0 2 2 2 2 2 2 2

0=Does not meet1=Partially meets2=Meets

180
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana Source: USGS/GEC

Scale:

Date: July 2010

ALTERNATIVE 33 AND ALTERNATIVE 39 COMPARISON

Map ID: 27850108-1874

!(

!(

LITTLE BAYOU CHENE BLANC

SE-1

NE-2 NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER

Railroad

377 Acres Grade

Secondary

Impact Area

443 Acres

Primary

Impact Area

Footprint =

13.3 Acres

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

Footprint =

18.8 Acres

1,033 Acres

Secondary

Impact Area

426 Acres

Primary

Impact Area

487 Acres

Proposed

Vegetative

Planting

SW-2

ALLIGATOR BAYOU

1:40,000

±

0 2,000 4,000 6,000

Feet

Map Extent

Legend

Subunits

Primary Impact Area

Secondary Impact Area

!( Existing Railroad Grade Cuts

Proposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material Berms

Conveyance Channel

Cut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

Proposed

Cut Through

Railroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Proposed

Cut Through

Railroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Proposed

Cut Through

Railroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of all Dredged

Material Berms, Conveyance Channels,and Cuts

Through Existing Dredged Material Berms.

Spaces between Dredged Material Berms are

shown larger than actual size for graphic purposes.

Figure: 3.27

!(

!(

LITTLE BAYOU CHENE BLANC

SE-1

NE-2 NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER

Railroad

Grade

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

SW-2

ALLIGATOR BAYOU

Map Extent

Legend

Subunits

Primary Impact Area

Secondary Impact Area

!( Existing Railroad Grade Cuts

Proposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material Berms

Conveyance Channel

Cut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

Proposed

Cut Through

Railroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of all Dredged

Material Berms, Conveyance Channels,and Cuts

Through Existing Dredged Material Berms.

Spaces between Dredged Material Berms are

shown larger than actual size for graphic purposes.

ALTERNATIVE 33 (TSP)

ALTERNATIVE 39 (NER)

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Table 3.16 Comparison of the NER and Recommended Plan

Alternative 39

(NER)

Alternative 33

(Recommended

Plan)

MCACES Costs

Channels & Canals $9,210,000 $4,450,000

Monitoring $3,660,000 $2,970,000

Construction Estimate Total $12,870,000 $7,420,000

Federal Share Construction Estimate $8,370,000 $4,820,000

Non-Federal Share Construction Estimate $4,500,000 $2,600,000

Lands & Damages $390,000 $180,000

Planning, Engineering & Design $1,110,000 $534,000

Construction Management $829,000 $401,000

Project Cost Total $15,200,000 $8,540,000

Federal Share Cost Total $9,880,000 $5,550,000

Non-Federal Share Cost Total $5,320,000 $2,990,000

Benefits

Benefits (AAHUs) 1,602 679

Annualized Cost/AAHU $480 $660

Notes: Costs represent the "fully funded" project estimate including interest during construction.

Discount Rate of 4.375 percent Utilized for Annualized Costs.

Table 3.17 Maximum Cost Including Inflation through Construction

Authorized cost in WRDA 2007 Title VII,

Section 7006 (e)(3)(A): $5,600,000

* Cost Index Used

EM 1110-2-1304 (Revised 31 Mar 2010)

CWBS Feature Code 09 – Channels and

Canals

Cost Index Ratio

1Q FY07 to 3Q FY15 1.20

** Current Project Cost Estimate

(Inflation applied from 10/2006 to 4/2015) $6,711,849

20% of Authorized Cost: $1,120,000

*** Monitoring & Adaptive Management:

(per WRDA 2007 Section 2039)

$2,971,200- $45,000

= $2,926,200

Maximum Cost Limited by Section 902: $6,711,849+ $1,120,000 +2,926,200

= $10,760,000

****Recommended Plan cost $8,540,000

Notes: * The cost index applied is derived from: EM 1110-2-1304, 31 Mar 10, Civil Works Construction Cost

Index System (CWCCIS).** For the purposes of applying the Cost Index to the WRDA Authorized Cost, each

project was adjusted for inflation from October 2006 price levels to the midpoint of construction.*** The cost of

any modifications required by law. This is derived from section 8.0 of each projects Monitoring and Adaptive

Management Plan minus the project monitoring cost found on the LCA Cost Summary Worksheet - October

2004 Price Levels modified study cost Dec 20 2004. Figures in calculations are actual and not rounded. Final

numbers in bold are rounded.****Represents fully funded cost estimate including interest during construction.

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• Dredged material (5.0 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps will

be left in the disposal berms so sheet flow is not reduced.

• One cut would be created in the railroad grade approximately 0.9 miles north

of the ARDC to improve sheet flow.

• Vegetative plantings of bottomland hardwood/freshwater swamp tree species

on 5.0 acres of dredged material berms.

• Vegetative plantings of freshwater swamp tree species within 438 acres of

the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against tree

loss.

• Environmental easements on 1,633 acres of land

Three natural low areas or relict channels have been identified as potential bank

opening and conveyance channel sites. Openings would enable impounded water to

be drained from the swamp and provide hydrologic connectivity between the swamp

and the ARDC. Additionally, the placement of a cut in the railroad grade would

provide further hydrologic connectivity between NE-1 and NE-2. Openings would

promote the introduction of freshwater, sediments, and nutrients into the swamp

and allow the oxidation of sediments and removal of toxic metabolites. This

alternative is anticipated to improve the degraded swamp and decrease the

transition to marsh and ultimately, open water. This alternative represents the

minimum effort that would meet the goals and objectives of the project.

Alternative 33 would benefit approximately 1,602 acres of existing freshwater

swamp, recreate 144 acres of freshwater swamp from freshwater marsh, and create

5.0 acres of upland habitat from dredged material placement.

All excavation through the dredged material berms, as well as the conveyance

channels through the swamp, would be based on four design cross-sections

(Figures 3.5 through 3.8). These cross-sections were developed in an effort to mimic

natural, existing cuts within the study area, which have been determined to be selfmaintaining. The cross-sections include a 70-foot wide cut section with benches

through dredged material berm, a 70-foot wide cut section, a 50-foot wide cut

section and a 30-foot wide cut section. The benches are 25-foot wide flat areas,

located above the average water level, on both sides of the conveyance channel.

These benches will be included in the portions of the conveyance channel to be cut

through the existing dredged material berms. The 70-foot cut section with benches

was designed to allow increased amounts of flow to pass beyond the existing

dredged material berm during high-water events. The material dredged from the

existing berms would be placed along the swamp-side of the excavated cut as new

bottomland hardwood habitat. All material dredged during construction of the

conveyance channels would be placed along the channels, with gaps included, to

allow sufficient sheet flow to be conveyed from the swamp. The quantities

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associated with each alternative are found in Table 3.5. Table 3.6 summarizes the

features associated with each alternative within the final array. A typical depiction

of the conveyance channels is found in Figure 3.9.

The Recommended Plan would provide environmental benefits as follows:

• Restoring and benefitting 1,602 acres of freshwater swamp habitat;

freshwater swamp habitat has been identified nationally as institutional,

public, and technical significance. This significance is due to the ecosystem

functions that include fish and wildlife habitat, water quality benefits,

pollutant filtration, groundwater charge and recharge, habitat for threatened

and endangered species, carbon sequestration, aesthetics, and recreations;

• Creating a net of 679 Average AAHUs; AAHUs are a measure of ecological

benefits as output from the WVA. An AAHU is the equivalent of improving

one acre from a totally non-functioning habitat (0 percent functioning) to a

fully functional one (100 percent), as well has to take two acres from a

50 percent functional level to a 100 percent functional level. More AAHU and

WVA detail are presented in 3.5.2. The benefits of this project would be to

essentially restore the equivalent on 679 acres of a 100 percent functioning

freshwater swamp from a 679 acres of a completely non-functioning habitat;

• Creating 5.0 acres of bottomland hardwood habitat;

• Establishing hydrologic connectivity between the ARDC and the western

Maurepas Swamp allowing the swamp to drain during seasonal low-flow

conditions in the Amite River and allowing nutrients and sediments to be

introduced from the ARDC into the swamp during flood events and from

runoff during localized rainfall events;

• Reducing the likelihood of the swamp being converted to marsh or open

water;

• Promoting the germination and survival of the seedlings of bald cypress and

other trees;

• Improving biological productivity and reducing further habitat deterioration.

3.7.2 Design, Environmental, and Construction Considerations

Design Considerations. Alternative 33 (Recommended Plan) utilizes the

addition of cuts in the north dredged material berms along with bifurcated

conveyance channels to reduce impoundment and increase hydrologic connectivity

between the ARDC and subunits NE-1 and NE-2. All cut locations were placed to

maximize the potential for flow into and out of the impounded swamp habitat.

Additionally, one cut is placed in the existing railroad grade to further reduce

impoundment and improve flow within these areas. All material dredged during

construction of the conveyance channels would be placed along the channels, with

gaps included, to allow sufficient sheet flow to be conveyed from the swamp.

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The cross-sectional dimensions of the conveyance channels were designed to

mimic natural cuts found within the southern portion of SE-2 and along Blind

River. These natural cuts facilitate drainage for an area similar in size to those

required in NE-2 and are considered to be in a state on hydrologic equilibrium. The

surveys of the existing channels are presented in Appendix L. These cuts represent

natural equilibrium dimensions which have formed based on drainage requirements

similar to the hydrologic subunits involved in this restoration study. Additional

cross-sectional area was provided for the cut portion within the existing dredged

material berms so as to allow high-water flows through this portion of proposed

conveyance system. Additional geotechnical data will be collected during PED and

will be used to verify the channel design (Appendix L).

Vegetative plantings are added to the most highly-degraded areas within

NE-2 to increase the potential for reversing habitat conversion and to provide a

seed source, thereby increasing vegetative regeneration within this portion of the

study area. These plantings will be implemented in two phases. A primary planting

will be implemented in the designated areas one year after the earthmoving phase

of construction is completed. The period of time between excavation and the

primary plantings will allow the disturbed material to compact into a more suitable

substrate. This time will also allow for the determination of an appropriate

planting scheme. Sixteen months after the primary plantings are completed; a

mortality analysis will be conducted to establish the quantity of plantings required

for the secondary planting. It is assumed that 50 percent of the initial plantings

will perish. Four months after this determination is made a secondary planting will

be implemented. Both the primary and secondary plantings will consist of 173 trees

per acre. Each acre planted will be composed of 75 percent bare-root, 15 percent

one-gallon potted, and 10 percent three-gallon potted plants. These plantings are

considered an important component of the restoration design, due to the native

regeneration they would provide for the highly degraded areas of impact. The

planting should only occur during the non-growing season (November to March) and

it is recommended that at least one year elapse after construction before planting

such that soils in the impounded areas could recover and the dredged material

berms reach a stable elevation. The plant list for the dredged material areas would

be developed based upon this final elevation.

3.7.3 Real Estate Requirements

Construction of Alternative 33 (Recommended Plan) would require the acquisition

of required easements to allow for the construction of the project and to ensure that

all project benefits are protected. These real estate acquisitions include flowage,

wetland, and channel easements for the appropriate portions of the construction

footprint. The real estate cost required for implementation of Alternative 33

(Recommended Plan) is estimated at approximately $180,000 (Appendix J).

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3.7.4 OMRR&R Considerations

OMRR&R requirements for Alternative 33 (Recommended Plan) include a yearly

inspection of the bank opening locations and conveyance channels to ensure that

there are no flow interruptions, such as from debris or fallen trees. Upon inspection

it would be determined if blockage removal or some other appropriate remedial

operation is required. Since the channel designs were based on stable, existing

channel that require no maintenance, no blockage is anticipated. However, some

maintenance is being planned for in the event that high water soon after

construction could move some debris and block the channel. Once these areas

stabilize, little to no maintenance would be required.

The conveyance channels would be naturally altered over time, eventually reaching

a state of hydrologic equilibrium similar to the relict channels that the conveyance

channels were designed to mimic. These changes would most possibly result in

changes to the geomorphology of the channel along with a transition to a more

meandering channel makeup and would not reduce the expected benefits of

Alternative 33 (Recommended Plan). Therefore, it is anticipated that little to no

attempt to maintain the depth or shoreline geometry of the conveyance channels

would be necessary. The non-Federal sponsor would be required to enforce any

restrictions as identified in the easements to ensure that the benefits of

Alternative 33 (Recommended Plan) are retained.

3.7.5 Monitoring Plan and Adaptive Management

3.7.5.1 Description of Monitoring Activity and Adaptive

Management

Monitoring is critical to understanding how effective a project is with respect

to meeting its goals and objectives. 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 discern ecosystem responses due to project

implementation (i.e., management actions) from natural variability. In coastal

Louisiana, there are many existing restoration and protection projects constructed,

and many more planned under a multitude of different authorizations and

programs, which will ultimately influence much of coastal Louisiana. Monitoring

must therefore be conducted at project and system-wide scales, and nested to

support long-term, large-scale status and trends and short-term performance

assessments.

When possible, specific monitoring and large scale information needs should

be integrated with monitoring efforts that are underway in coastal Louisiana. The

Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA) produced a

program that has been monitoring restoration and protection projects in coastal

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Louisiana since 1990 (Steyer and Stewart 1992, Steyer et al. 1995). The monitoring

program incorporates a system-level wetland assessment component called the

Coast-wide 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 and protection projects in

coastal Louisiana. LCA monitoring plans should benefit from existing monitoring

networks to the extent practicable and participate in the implementation of CRMSWetlands. The CRMS stations, which are capable of monitoring RSLR, could also be

utilized in the future as a means of adaptive management for RSLR. Consideration

could be given to additional monitoring efforts as well. Such participation can

maintain the data consistencies necessary to conduct project assessment and

programmatic adaptive management.

A feasibility level monitoring and adaptive management (AM) plan has been

developed for the project (Appendix I). The monitoring and AM plan was developed

to include the proposed monitoring and to consider and identify any necessary AM

activities. The plan also estimates the costs and duration of the monitoring and

applicable AM components.

The primary incentive for implementing an adaptive management program is

to increase the likelihood of achieving desired project outcomes in the face of

uncertainty. Adaptive management provides an organized, coherent and

documented process that defines management actions in relation to measured

project performance compared to desired project outcomes.

Principal sources of uncertainty common to management and restoration

projects include (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) incoherent management and decision-making

processes.

In the case of the LCA-ARDC Modification project, the following questions

were considered to determine if adaptive management should be applied to the

project. A “NO” answer to questions 1 through 3 and a “YES” answer to question 4

indentifies the project as a candidate that could benefit from adaptive management.

(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 project’s performance well

understood and agreed upon by all parties?

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(4) Can project management actions be adjusted in relation to monitoring

results?

Answers to questions 1 through 3 were “NO.” However, the Adaptive

Management Framework Team determined that the Amite River Diversion Canal

Modification project was not a good candidate for adaptive management because

there are no actions that could be taken in response to monitoring results that the

USACE would define as adaptive management actions. That is, the answer to

question 4 is “NO.” Although some activities could be conducted to adjust project

performance, these actions would not be considered adaptive management

activities. O&M for the selected plan includes a yearly inspection of the bank

opening locations and conveyance channels to ensure that there are no flow

interruptions, such as from debris or fallen trees, which could improve project

performance. However if monitoring data indicate that actions beyond yearly O&M

(i.e changing the shape, size, branching, or number of conveyances channels or

gaps) would be needed these would be considered structural changes and are

beyond the adaptive management authority. The USACE and State of Louisiana

can initiate the process for developing a new water resources project or pursue a

design deficiency under the constructed project. The Framework Team also

considered opportunities for active adaptive management by designing the project

as a management experiment. The Team determined there were minimal active

adaptive management opportunities for the project and that any lessons learned

would be limited and would not likely apply to other coastal Louisiana restoration

projects. While there are currently no apparent adaptive management

opportunities, the Adaptive Management Planning Team can examine the

performance of the project in the future. If it is determined during PED that

adaptive management could help achieve any unfulfilled project objectives, the

Team can recommend adaptive management for the project at that time.

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 central to properly assessing the effects of the Amite River

Diversion Canal Modification project.

3.7.5.2 Performance Measures for Monitoring

The plan identifies performance measures along with desired outcomes and

monitoring designs in relation to specific project goals and objectives. Additional

monitoring is identified under supporting information needs to help further

understand and corroborate project effects;

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Objective 1:

Performance Measure 1: Freshwater distribution during operational

events

Increase hydrologic connectivity between the degraded swamp

and bottomland hardwood habitats within the study area and the ARDC by

increasing the exchange of freshwater, sediments, and nutrients.

Desired Outcome: Increase hydrologic connectivity and area of extent of

freshwater movement into project area above pre-project conditions.

Monitoring Design: Synoptic hydrologic surveys, using salinity,

temperature, dissolved oxygen, and velocity as tracers, will be conducted

during selected low flow and high flow operational events to track

distribution of freshwater. Sampling will be conducted twice annually in the

first three years and as required thereafter.

Objective 2: Facilitate natural hydrologic cycles within the study area by

reducing impoundment in degraded swamp and bottomland hardwood

habitats adjacent to the ARDC which would improve tree productivity and

seedling germination.

Performance Measure 2a: Swamp vegetation production and extent.

Desired Outcome: Increase in basal area increment of baldcypress and

tupelo in the swamp from existing conditions (existing conditions defined

from pre-construction measurements from CRMS-Wetlands stations and

Southeastern Louisiana University historical monitoring).

Monitoring Design: Diameter at breast height (dbh) and overstory tree

cover will be measured in the fall in two pre-construction years and four postconstruction years (within the first 10 years).

Performance Measure 2b: Number of baldcypress and tupelo saplings.

Desired Outcome: A 25 percent increase in the number of naturally

recruited baldcypress and tupelo saplings per acre from pre-project conditions

10 years after project implementation. Performance of this measure is most

dependent on achieving extended dry periods in the swamp.

Monitoring Design: Understory vegetation (herbaceous, seedling, and

sapling) will be measured in the fall in two pre-construction and four postconstruction years (within the first 10 years) to assess regeneration and

changes in cover classes.

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Performance Measure 2c: Depth, duration and frequency of flooding in the

swamp.

Desired Outcome: Increase or decrease from pre-project conditions average

flood durations (existing conditions defined from pre-construction

measurements from CRMS-Wetlands stations).

Desired Outcome: Maintain dry periods (moist soils) in the swamp for a

minimum 7-35 days during summer and early fall for seed germination and

maintain water levels below seedling height to promote seedling survival.

Monitoring Design: Water-level recorders will be deployed in six key areas

to measure water depths at the needed frequencies. Recorders will be

established three years prior to construction to determine existing conditions

and will be monitored for 10 years post-construction or until desired

outcomes are achieved.

Supporting Information Need: A deep rod-surface elevation table (RSET)

rod will be installed where hydrologic measurements are taken to establish

an elevation benchmark.

Objective 3: Reduce habitat conversion from swamp to marsh and open

water within the study area.

Performance Measure 3: Habitat and land:water classification

Desired Outcome: Maintaining immediate pre-construction acreage of

baldcypress-tupelo swamp acreage after 10 years.

Monitoring Design: Habitats will be classified using Landsat Thematic

Mapper (TM) scenes and Digital Orthophoto Quarter Quadrangles (DOQQs)

for one pre- and four post-project years in the study area to assess trends in

conversion between swamp, herbaceous marsh, and open water.

Supporting Information Need: Salinity data will be collected in order to

characterize potential salinity stress associated with low water conditions in

the fall, droughts, and intrusions associated with tropical cyclone events.

Objective 4: Improve fish and wildlife habitat within the study area.

Performance Measure 4: No applicable performance measure.

Desired Outcome: Swamp production and hydroperiod measures will be

used to assess this objective.

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Monitoring Design: Fish and wildlife habitat is linked to the performance

measures associated with objectives 1-3, focused on improving habitat.

Therefore, no specific monitoring is proposed for this objective.

3.7.5.3 Cost and Duration of Monitoring and Adaptive

Management

The costs associated with implementing the monitoring and adaptive

management plans was 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 will be need to be

refined in PED during the development of the detailed monitoring and adaptive

management plans. The estimated cost for the monitoring program is $2,970,000

over 10 years, following the completion of project construction. These costs are

budgeted as construction costs.

In accordance with WRDA 2007 Section 2039 the monitoring costs presented

in the report are for the full allowable 10-year period and represent conservative

and comprehensive cost. Section 2039 guidance does allow for the monitoring to

end prior to the 10-year period if the Secretary determines that the success criteria

have been met. The costs presented in the report are for the full 10-year period but

may end much sooner than 10 years. The monitoring plans and costs were

developed by the interagency LCA Adaptive Management Planning Team in

conjunction with stakeholders and have been determined to be a reasonable plan

and estimate for what is needed and necessary to be able to determine project

success.

3.7.6 Effectiveness of Recommended Plan in Meeting

Goals and Objectives

The proposed action selected as the Recommended Plan, meets all of the goals and

objectives listed in Section 2.4 of this study and has been determined to have

minimal impacts on significant resources, as described in Table 3.15. The manner

in which each objective and goal is achieved is listed below.

Objective 1: Increase hydrologic connectivity between the degraded swamp

and bottomland hardwood habitats within the study area and the ARDC by

increasing the exchange of freshwater, sediments, and nutrients over the 50-year

period of analysis.

With the addition of cuts and conveyance channels, H&H modeling has

shown that hydrologic connectivity would be increased within the designated areas

of impacts for the subunits determined to be in the most need of restoration. This

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connectivity would add to the seasonal flows needed to maintain healthy swamp

habitat and would increase the exchange of sediments and nutrients between the

ARDC and the interior swamp areas.

Objective 2: Reduce habitat conversion of swamp to open water within the

study area over the 50-year period of analysis.

With implementation of Alternative 33 (Recommended Plan), added

conveyance, reduced impoundment, and implementation of vegetative plantings,

would result in a reduction of habitat conversion to freshwater marsh for 1,602

acres of degraded cypress-tupelo swamp. It is also anticipated that the regeneration

of native swamp vegetation would be increased with the implementation of this

proposed action, thereby creating a self-sustaining swamp habitat.

Objective 3: Facilitate natural hydrologic cycles within the study area over

the 50-year period of analysis by reducing impoundment in degraded swamp and

bottomland hardwood habitats adjacent to the ARDC to improve tree productivity

and seedling germination.

The cuts placed within the existing dredged material berm, along with the

conveyance channels, would allow the swamp habitat adjacent to the ARDC to drain

high-salinity waters introduced by tropical storm events and allow for seasonal

hydrologic flow to occur within the areas of impact. The increased conveyance

observed from seasonal hydrology would produce increased sheet flow, resulting in

nutrient and sediment input as well as a flushing action for the areas of impact

within Alternative 33 (Recommended Plan). This would produce the type of

hydrologic cycles required to maintain and promote healthy swamp habitat. The

resulting reduction in impoundment will increase the number of dry days occurring

within the areas of impact, in turn increasing seed germination and promoting

natural succession.

Objective 4: Improve fish and wildlife habitat within the study area over the

50-year period of analysis.

The implementation of Alternative 33 (Recommended Plan) would improve

the ecosystem by creating a net gain of 679 AAHUs within the areas of impacts.

These benefits quantify habitat improvements for fish and wildlife that thrive in

cypress-tupelo swamp habitat. The placement of the dredged material along the

proposed conveyance channels, existing railroad grade, and existing dredged

material berms would also provide areas of bottomland hardwood habitat for

wildlife to use during high-water periods. The vegetative plantings on the placed

dredged material and within the degraded swamp also provide habitat diversity and

sustainability within the areas of impact.

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3.7.7 Effectiveness of Recommended Plan in Meeting Environmental

Operating Principals

Alternative 33 (Recommended Plan) would benefit 1,602 acres of cypress-tupelo

swamp habitat, resulting in a net gain of 679 AAHUs with little to no negative

environmental impacts. This would reverse the trend of conversion from swamp to

freshwater marsh habitat within the areas of impact, while adding habitat

sustainability and diversity. The Recommended Plan provides a significant amount

of benefits and has been agreed upon by the PDT, including Federal and state

agencies, as being the most beneficial plan within the authorized cost for the study

area.

3.7.8 Compensatory Mitigation Measures

Implementation of Alternative 33 (Recommended Plan) would result in a net gain in

wetland habitat; therefore, compensatory mitigation, as stipulated in the Clean

Water Act, is not required. In order to offset the loss of habitat resulting from the

placement of dredged material within the areas of impact, 5.0 acres of vegetative

plantings of additional tree species, such as sweet gum and live oaks, would be

implemented on the placed material to create bottomland hardwood habitat. This

habitat could be utilized by some wildlife for available land and food during highwater periods. The addition of these areas also provides habitat diversity within the

areas of impact. The Recommended Plan would result in a net gain in habitat units;

therefore, no compensatory mitigation for construction of this project is required.

3.7.9 Micro-Computer Aided Cost Estimating System

In order to obtain a more thorough analysis of the costs associated with the

recommended plan (Alternative 33), a Micro-Computer Aided Cost Estimating

System (MCACES) cost estimate was conducted on the recommended plan. This

estimate included all items listed in Section 3.5.1 of this report, with the addition of

various project-specific considerations such as contingencies and localized cost items

such as sales tax and labor rates. The contingency costs were determined based on

a risk analysis as shown in Section 3.8 of this report. The overall cost of the

recommended plan was estimated to be $8,540,000 (fully funded). The full MCACES

estimate report may be found in Appendix L of this report.

3.7.10 Construction Considerations

It is estimated that construction of the earthmoving portion of the recommended

plan (Alternative 33) would take approximately six months. This duration includes

the mobilization and demobilization of the required equipment and laborers and the

construction of all three gaps and conveyance channels. The first implementation of

vegetative plantings within the appropriate swamp and bottomland hardwood

habitat would commence approximately 12 months after completion of earthmoving

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construction. This period of time is required to allow the impounded soils to recover

and to allow the dredged material berms to settle. The final elevation of the

dredged material berms is a critical component of determining the correct tree

species to plant. Supplementary plantings would likely be required at a later date,

depending on the mortality rate of the first plantings. It is estimated that the

secondary plantings would commence approximately 28 months after the initial

plantings are completed. A chart depicting the construction schedule as well as the

planting contract schedule can be found in Appendix L.

Once the appropriate equipment is mobilized to the project site via trucks and

barges, construction of the gaps would commence by clearing and grubbing the

designated footprints of construction on both sides of the ARDC. Stumps are to be

removed from the portions of excavation within the proposed channels, but only

trees would be cleared along the benches, 10-foot gaps and material placement

areas. Cleared trees would be placed in the same area with the stumps and dredged

material in a manner that does not impede hydrologic connectivity. Once clearing is

completed at one cut location, the equipment would be mobilized to another cut

location so excavation could begin.

Excavation of the cuts within the existing dredged material berms and the proposed

conveyance channels would be carried out by a short-reach, hydraulic excavator

mounted on flexi-float mats or amphibious equipment. As the equipment cuts its

way into the cut locations, the dredged material would be placed along the cuts and

conveyance channels as shown in Figure 3.9. The excavated cuts and channels

would serve as the area in which equipment would move in and out of the

construction area. Some amphibious equipment would most likely be needed to

accomplish the incremental movement of the mats.

Upon completion of the excavation, vegetative plantings would be carried within the

predetermined areas of the swamp and material placement. Approximately 173

trees per acre would be planted. Each area planted would consist of approximately

25 percent potted seedlings and 75 percent bare-root seedlings. Cypress and tupelo

gum would be planted within the swamp floor areas and hardwoods such as live

oaks and sweet gum would be planted on both the newly created and existing

dredged material berms. The final species list would have to be determined after

the dredged material berms settle to ensure the correct trees are planted. Nutria

guards would be required on every tree planted in order to ensure a reasonable

success rate. It is expected that the replanting of 50 percent of these areas would be

necessary within a few years of the conclusion of cut and channel construction. The

monitoring activities required for this project, such as the mortality of vegetative

plantings, are found in Appendix I. No relocations of infrastructure or utilities

would be required during construction of the Alternative 33 (Recommended Plan).

The estimated schedule for project implementation is shown in Table 3.18.

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3.7.11 Significance

Ecosystem restoration is one of the primary missions of the USACE Civil Works

program. The USACE's objective in ecosystem restoration planning is to contribute

to national ecosystem restoration (NER). Contributions to NER (outputs) are

increases in the net quantity and/or quality of desired ecosystem resources.

Measurement of NER is based on changes in ecological resource quality as a

function of improvement in habitat quality and/or quantity, and is expressed

quantitatively in physical units or indexes. These net changes are measured in the

planning area and in the rest of the Nation.

Louisiana contains one of the largest expanses of coastal wetlands in the contiguous

United States and accounts for 90 percent of the total coastal wetland loss occurring

in the Nation. The Maurepas Swamp complex is the second largest continuous

coastal forest in Louisiana, comprising over 190,000 acres of freshwater swamp

habitat. The LCA ARDC study area is an essential ecosystem since it includes

wetland habitats and provides high fish and wildlife value as well as habitat for

migratory birds and other aquatic organisms including threatened or endangered

species.

The swamp habitat surrounding the ARDC has been historically used for hunting,

fishing, bird watching, and trapping. The restoration of the freshwater swamp

habitat surrounding the ARDC would protect these national assets from further

degradation. The restoration and protection of this swamp system will further

protect the human infrastructure from the damages of storm surges and would

protect the habitat for many species, including neotropical migrants.

3.7.11.1 Rationale for the Recommended Plan

The Recommended Plan meets both 2004 and current planning objectives.

The Recommended Plan is an implementable increment of the NER plan, has been

determined to be cost effective, is within the cost and scope of the authorization, has

stand-alone utility, is supported by the non-Federal sponsor, and can be justified

based on ecosystem restoration benefits, and addresses problem stipulated by the

CEM. The Recommended Plan will restore 1,602 acres of cypress-tupelo swamp

habitat and will create five acres of bottomland hardwood habitat for the 50 year

period of analysis. Freshwater swamp habitat for essential fish and wildlife species

will be restored, 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.

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Table 3.18 Recommended Plan (Alternative 33) Construction Schedule 1

ARDC Alternative 33 Earthmoving Construction Schedule

Dredged Material Berm Swamp Equipment Utilized (Hours)

Week* Mob Clear Trees Land-Based Earthwork Marsh Backhoe Work Clear Trees Marsh Backhoe Work Log Skidder D6 Dozer Marsh Backhoe Barge Tug Boat 900hp Crew Boat**

NTP

2 MOB 403 40 40 80 40 40 404 Cut 1 40 40 80 40 405 Cut 1 40 40 80 40 406 Cut 1 Cut 1 40 40 80 40 20 407 Cut 2 40 40 80 40 408 40 40 80 40 409 Cut 2 Cut 2 40 40 80 40 20 40

10 Cut 3 Cut 1 40 40 80 40 4011 Cut 2 40 40 80 40 4012 Cut 3 Cut 3 40 40 80 40 20 4013 80 40 4014 80 40 4015 80 40 4016 Cut 2 80 40 20 4017 Cut 3 80 40 4018 80 40 4019 80 40 4020 80 40 4021 80 40 4022 Cut 3 80 40 4023 Demob 80 40 40 40

Totals 400 400 1,680 840 160 880

* Cells are completion by end of specific week

** Contingency Hours Added for Repairs Etc.

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The project will restore natural hydrologic connectivity to the interior swamp

surrounding the ARDC, while also reducing impoundment. The increased

connectivity will result in increased sediment and nutrient input, which will

facilitate seed germination and increase tree growth and canopy within the areas of

impact. This increase in vegetative productivity will allow the restored area to

continue to function and provide habitat with minimum continuing intervention.

Without this project, the LCA ARDC study area will continue to degrade, with the

eventual conversion of 18,204 acres of freshwater swamp habitat to marsh and open

water. By reducing the impoundment of storm surge and restoring overland flow to

the swamp habitat surrounding the ARDC, the Recommended Plan would allow the

ecosystem to "self-regulate," by letting natural hydrologic and ecosystem processes

to 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 Maurepas swamp

provides important hydrologic and habitat functions within the wetlands of coastal

Louisiana. Loss of these functions would have impacts beyond the project study

area.

Problems discussed in Section 1.5 of the November 2004 Louisiana Coastal

Area (LCA) Ecosystem Restoration Study, as well as how they are addressed by the

ARDC Modification study, are listed below:

- Subsidence is caused by a lack of sediment replenishing the soil that is

removed from an area due to natural erosion or other forces. The

Recommended Plan will address this problem by allowing hydrologic

connectivity which will introduce sediments to the study area. Additionally,

increases in canopy will result in increased biomass accretion, thereby

reducing the impacts of subsidence.

- Habitat switching, occurs when one habitat converts 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. 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. More specifically, the study area is in danger

of switching from a freshwater swamp to a marsh, and then potentially to

open water. Through increased hydrologic connectivity, the Recommended

Plan allows for nutrient and sediments to be introduced to the area to

nourish the swamp and encourage indigenous flora and fauna to remain,

thereby keeping the habitat intact. Vegetative plantings will help accelerate

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and sustain the restoration of the swamp habitat by providing a seed source

for vegetative regeneration.

- Erosion of wetlands is a result of stormwater runoff carrying sediment

away that will not be replenished. The hydrologic connectivity created by the

Recommended Plan would lead to the improvement of freshwater swamp

habitat, increased basal width, and increased canopy. These improvements

will prevent the further conversion of the native habitat.

- Isolation from sediment and nutrients has occurred as a result of the

construction of the ARDC. This problem will be corrected by the proposed

cuts in the dredged material berm, leading to hydrologic connectivity.

- Saltwater intrusion occurs when salt water brought in by high tide, storm

events or some other method is not able to drain effectively from an area.

Improving hydrologic connectivity to the study area would allow for

impounded salinity to be flushed out more effectively.

- Human-built infrastructure has modified the hydrology in the area.

This is the root cause of many of the problems identified in the ARDC study

area. This will be addressed by making cuts in the ARDC dredged material

berm and allowing for hydrologic connectivity between the ARDC and the

surrounding study area.

- The Mississippi River sediment load is deposited in deeper Gulf of

Mexico due to the controlling of the route of the Mississippi River. This

marginally contributes to the problems in the ARDC study area, but

measures to address this issue are outside the scope of this project.

- A decline in sediment load from the Mississippi River also contributes

to the issues in the ARDC study area, but measures to address this issue are

outside the scope of this project.

The project objectives addressed through implementation of the

Recommended Plan are described in Section 3.7.6 of the report.

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. The western Maurepas swamp serves as stopping

ground for neotropical migratory bird species and provides habitat for bald eagles,

Gulf sturgeon, and the West Indian Manatee. 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. The ARDC

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and the surrounding swamp habitat are utilized for camping, fishing, and holiday

celebrations. Commercial and recreational fishing are culturally significant to many

south Louisiana residents. The wetlands provided by the western Maurepas swamp

are nurseries for many fish species.

3.7.11.2 Significance of Recommended Plan

The outputs provided by the Recommended Plan are technically recognized.

Examples of technical significance are:

• Scarcity: Louisiana's coastline represents 90 percent 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 project footprint is uninhabited. The

Recommended Plan will restore the interior swamp habitat by restoring

natural flow regimes and using plantings of tree species native to the

surrounding area.

• Status and Trends: The study area is exhibiting a decline in habitat.

While the project cannot stop the natural processes of sea level rise and

subsidence, the project can greatly slow down the disappearance of these

landforms by decreasing impoundment and increasing hydrologic

connectivity and flushing, as well as sediment and nutrient input within

the areas of impact.

• Connectivity: The Maurepas swamp complex is the second largest

continuous coastal forest in Louisiana. With the continued conversion of

this habitat to marsh and open water, 18,204 acres of freshwater swamp

habitat would be converted to marsh and open water. The swamp is also

a valuable stopover habitat for neotropical migratory birds.

• Limiting Habitat: The LCA ARDC study area is considered habitat for

bald eagles, Gulf sturgeon, and Western Indian manatee.

The Recommended Plan meets the four evaluation criteria specified in the

USACE Planning and Guidance.

3.7.11.3 Acceptability

The Recommended Plan is acceptable to the State and the Federal Agencies.

The Recommended Plan was selected by an interagency and interdisciplinary team.

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There is broad based public support for the plan. The agencies' and public's

greatest concern is beginning construction as soon as possible.

3.7.11.4 Completeness

The plan provides and accounts for all necessary investments and actions to

ensure the planned restoration outputs specified in the Recommended Plan. The

plan prevents the continued degradation of 1,602 acres of freshwater swamp habitat

to marsh and open water over the 50-year period of analysis. Consequently, the

project improves the potential for long term survival of the wetland habitat within

the areas of impact.

3.7.11.5 Efficiency

The Recommended Plan was identified as cost effective by the IWR Planning

Suite analysis.

3.7.11.6 Effectiveness

The plan makes a significant contribution to addressing the specific

restoration problems for the swamp habitat surrounding the ARDC. Restoring

hydrologic connectivity for the ecosystem will facilitate an increase in sediment and

nutrient introduction to the degraded habitat and reduce impoundment. The added

connectivity will also increase the flushing action, thereby reducing salinity levels.

The Recommended Plan will result in an improved and sustainable ecosystem that

provides benefits throughout the 50-year period of analysis of the project.

The LCA 2004 report states that, "Gapping the ARDC will allow floodwaters

to introduce additional nutrients and sediment into western Maurepas Swamp. The

exchange of flow would occur during flood events on the river and from the runoff of

localized rainfall events. This feature would provide nutrients and sediment to

facilitate organic deposition in the swamp, improve biological productivity, and

prevent further swamp deterioration.” While the project will not stop the natural

force of sea level rise and subsidence, the project will return hydrologic flow

throughout the swamp habitat to its natural state, allowing for the sustainable

restoration and regeneration of wetlands within the western Maurepas swamp.

3.7.12 Sustainability

Among the planning criteria utilized in the evaluation of proposed actions in

ecosystem restoration projects, the significance and sustainability of ecosystem

outputs achieved over the period of analysis are among the most critical. While

some solutions provide immediate solutions to problems found within the project

study area, the sustainability of benefits achieved leads to a continued solution to

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natural and man-made causes of habitat degradation. Additionally, a sustainable

solution increases the significance of the proposed action as it pertains to significant

resources and local and nationwide restoration efforts. Within the LCA ARDC

study area, issues such as subsidence and sea level rise provide the potential for

long-term reductions in any benefits derived from a proposed action.

As stated in Section 2.3.3.3 of this report, over the 50-year period of analysis, RSLR

could potentially reduce the long-term functionality and quality of the freshwater

swamp habitat found within the LCA ARDC areas of impact. In order to fully

ascertain the impacts of the proposed actions found in the final array of

alternatives, an analysis of the sustainability of benefits within each action is

required. For planning purposes, the expected benefits for the final array were

calculated by the WVA model in the form of AAHUs. A full breakdown of the

AAHUs achieved for the final array is found in Section 3.5.2. These benefits

represent the average annual benefits observed over the period of analysis at year

50. For the low estimate of RSLR, Alternative 33 (Recommended Plan) is expected

to achieve 679 AAHUs by year 50. As shown in Section 3.8, benefits in habitat

units will decrease by 7 percent and 10 percent for the intermediate and high RSLR

estimates, respectively. Benefits provided by the WVA model for the No-Action

alternative and the Recommended Plan, in terms of non-annualized habitat units

(HUs) over the 50-year period of analysis are shown in Figures 3.28 and 3.29 and

Table 3.19. The net HUs achieved for each RSLR estimate are also shown.

Figure 3.28. Comparison of Habitat Units over the Period of Analysis

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00

1600.00

0 10 20 30 40 50 60

HUs

Years to Marsh

Comparison of HUs Alternative 33

Alternative 33 With Project Low

Alternative 33 With Project

Intermediate

Alternative 33 With Project High

Alternative 33 Without Project

Low

Alternative 33 Without Project

Intermediate

Alternative 33 Without Project

High

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Figure 3.29. Net Benefits Obtained Over Period of Analysis

Table 3.19. Comparison of Habitat Units Obtained

from the Recommended Plan Over Period of Analysis

Habitat Units Over Time for the Recommended Plan

Alternative/RSLR Estimate Year of Analysis

0 1 10 25 50

No-Action - Low RSLR 757 762 636 562 518

No-Action - Intermediate RSLR 757 761 634 517 461

No-Action - High RSLR 757 761 624 497 425

Alternative 33 - Low RSLR 757 889 1047 1390 1466

Alternative 33 - Intermediate RSLR 757 889 1047 1297 1327

Alternative 33 - High RSLR 757 888 1023 1249 1228

Net Benefits Achieved - Low RSLR 0 127 410 828 948

Net Benefits Achieved - Intermediate RSLR 0 128 413 780 866

Net Benefits Achieved - High RSLR 0 127 400 752 804

The results show that the impacts resulting from RSLR in general are fairly

consistent for all estimates of RSLR and appear to begin near year 20 of the period

of analysis. Furthermore, for all three estimates of RSLR, the amount of benefits

observed appear to stabilize near year 25, with a continued, but gradual increase in

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

900.00

1000.00

0 10 20 30 40 50 60

HUs

Year of Analysis

Net Benefits (HUs) for the TSP

Alternative 33 Low

Alternative 33 Intermediate

Alternative 33 High

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benefits over the next 25 years. This is an indicator that the proposed action

achieves sustainability for the remainder of the period of analysis, with no

reduction in benefits present regardless of the sea level rise scenario realized. It

should also be pointed out that after 10 years, the areas of impact will achieve a

net of approximately 400 HUs; this substantiates the short-term benefits resulting

from the Recommended Plan as well.

The data presented in the above table and figures is representative of a freshwater

swamp habitat with restored hydrologic connectivity and increased sediment and

nutrient input. This results in increased seed germination, regeneration of native

vegetation, and a more sustained and stable freshwater swamp. As shown in

Table 3.14 vegetative, hydrologic, wildlife, and fishery resources are benefited by

the implementation of the Recommended Plan. Even though RSLR could

potentially impact the area over the 50-year period of analysis, benefits are

observed in the short-term and maintained in the long-term frames of analysis. It

should also be pointed out that accretion, which would increase with added tree

growth and canopy, was not included in the analysis of RSLR. It is estimated that

the net accretion rate would be 8mm/year, within the healthiest portions of the LCA

ARDC study area (Bernard Wood, unpublished data, 2005 through 2009). These

net accretion rates account for subsidence, but not eustatic sea level rise. Based on

these estimates, accretion rates could reduce the potential impacts of sea level rise

within the healthiest portions of the LCA ARDC study area, thereby adding to

sustainability.

Approximately 90 percent of the total coastal wetland loss occurring in the Nation is

found within Louisiana. The Maurepas Swamp complex is the second largest

continuous coastal forest in Louisiana, comprising over 190,000 acres of freshwater

swamp habitat. The LCA ARDC study area is an essential ecosystem since it

includes wetland habitats and provides high fish and wildlife value as well as

habitat for migratory birds and other aquatic organisms including threatened or

endangered species. The significance of the ecosystem output plays an important

role in ecosystem restoration evaluation according to section E-37 of ER 1105-2-100.

The resulting ecosystem sustainability reinforces that all project objectives are

achieved and maintained by implementation of the Recommended Plan. This, along

with the significance of the resources benefited by this action, adds to the local and

national importance of this restoration activity.

3.8 RISK AND UNCERTAINTY

Identification of all risks and uncertainties involved with development and

implementation of Alternative 33 (Recommended Plan) help to develop risk

management techniques and quantify cost estimate contingencies. The following

risks and uncertainties are involved with development, selection, and construction

of the Recommended Plan. Regardless of the associated risks, this project has been

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developed to feasibility-level standards. The risks associated with the project will

not impact plan selection or significantly alter the analysis of project benefits and

impacts. All risk items associated with the LCA ARDC Modification project may be

found in Appendix L.

Modeling Uncertainty. Models such as the WVA allow for the prediction of

environmental benefits over periods of time and a range of conditions. However,

they are highly dependent on input from existing data and the use of best

professional judgment. The uncertainties inherent to the natural processes

quantified by these models could affect the results. Relative sea level rise was

determined to be the variable with the most uncertainty and therefore, could pose

the greatest impact to the modeling results. In an effort to quantify these impacts,

the WVA was run for all three levels of RSLR provided by EC 1165-2-211. When

compared to the low sea level rise estimate, the results showed a decrease in

benefits of 7 percent and 10 percent for the intermediate and high estimates,

respectively. Additionally, RSLR and accretion estimates were utilized when

developing the input variables for the WVA model as described in Appendix K.

While the basis for RSLR and accretion are described in Section 5.2, any

inaccuracies inherent to these natural processes would impact the results of the

WVA model.

Cost and Schedule Risks. Cost estimates are a key component for the IWR

Planning Suite analysis and in choosing a plan. Cost contingencies are included in

estimations of cost to help minimize these risks. Cost contingencies are typically

determined by a full Cost and Scheduling Risk Analysis (CSRA). Preliminary cost

estimates for the Recommended Plan were below $40 million; therefore, a full CSRA

is not required for the Recommended Plan, as stipulated in the USACE Cost and

Scheduling Risk Analysis Guidance (ER 1110-2-1302). However, in an effort to

identify the applicable cost and schedule risks inherent with implementation of the

Recommended Plan, much of the process found within the USACE guidance was

utilized. Once all potential areas of risk were agreed upon by the evaluation team,

a Risk Register was created to help qualify and quantify the potential impacts of

these risks. A Monte Carlo simulation (random occurrence generator) was run on

the registry, which yielded the applicable cost contingency to use for estimating

construction costs for Alternative 33 (Recommended Plan). For this study it was

determined that the appropriate contingency to use is 59 percent. This cost

contingency was applied to all cost accounts associated with the project except

monitoring costs, which already contains a contingency cost. The application of the

59 percent contingency to the applicable accounts results in an overall project

contingency of 31 percent. Due to the fact that all alternatives within the final

array are composed of similar management measures and within areas similar in

size and characteristics, it was determined that all risk items formulated in the

CSRA would not vary for each proposed action. Additional details on the Cost Risk

Analysis are found in Appendix L, Section 10.

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Subsidence. Based on guidance provided in EC-1165-2-211, subsidence

occurs within the LCA ARDC study area at a rate of 7.5 mm/yr. Subsidence plays a

role in the occurrence of RSLR and could increase the impacts of storm surge and

salinity spikes, thereby reducing any potential benefits associated with the

proposed action. As shown in Section 3.7.12, upon permanent inundation, benefits

would be observed throughout the 50-year period of analysis for the Recommended

Plan. However, subsidence may limit benefits provided by the proposed action.

Biomass accretion associated with healthy freshwater swamp habitat may offset the

negative impacts resulting from subsidence and RSLR. Additional discussions on

subsidence are located in Sections 2.3.3.2 and 5.2 of this report.

Sea Level Rise. Sea level rise has the ability to affect the coastal regions of

the United States and Louisiana in varying degrees. The result of these potential

impacts may include losses in project effectiveness, failure to achieve project

objectives, and escalating operations, maintenance, repair, replacement, and

rehabilitation (OMRR&R) costs. Guidance provided from EC-1165-2-211 estimates

these impacts as stipulated in Section 5. Specifically, within the LCA ARDC study

area, sea level rise is predicted to increase from 1.5 ft (0.46 m) to 3.2 ft (0.97 m) over

the 50-year period of analysis but is not expected to negate project performance or

benefits. The risks associated with RSLR were considered in the formulation of all

risk items during the CSRA performed for this project. The risk items in which

RSLR was considered pertinent include vegetative plantings mortality and

inaccuracies in the project scope (i.e., effects of RSLR may inhibit restoration

opportunities available to this project).

In order to gauge the effects of RSLR on the recommended plan, the WVA

model was run for Alternative 33 (Recommended Plan) and Alternative 39 (NER)

over the 50-year period of analysis of the project. The impacts of the intermediate

and high sea level rise estimates were added to the analysis in addition to the low

estimate, which was run as the base-line condition. The results showed a decrease

in benefits (AAHUs) from the low estimate of approximately seven percent when

the intermediate estimate was modeled and a decrease of approximately 10 percent

with the high estimate. Both alternatives displayed similar results. The results of

this analysis may be seen in Table 3.20. More details on sea level rise are found in

Appendix L.

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Table 3.20. Effect of Relative Sea Level Rise on Alternatives

Effect of Relative Sea Level Rise on Alternatives

Alternative Low SLR

(AAHUs)

Intermediate SLR

(AAHUs)

High SLR

(AAHUs)

33 679 640 610

34 589

35 334

36 1,268

37 922

38 1,013

39 1,602 1,516 1,452

Additionally, the Hydrologic Engineering Centers River Analysis System

(HEC-RAS) model was run with all three estimates of RSLR for the No-Action

alternative and the Future With Project conditions (conditions are nearly the same

for both swamp areas). The results of these model runs are shown in Table 3.21.

Results show that without the project the area will be inundated much sooner than

with project conditions. The project is still expected to produce benefits even if it is

inundated refer to Section 3.5.2. Additional discussions on sea level rise are located

in Sections 2.3.3.3 and 4.2.2.1 of this report.

Table 3.21. Years to Permanent Inundation

RSLR Case RSLR Year 50 No Action With Project

Low Rate 1.5 feet 14 years 40 years

Intermediate Rate 1.9 feet 12.5 years 31 years

High Rate 3.2 feet 8 years 17 years

Accretion. Healthy freshwater swamps with an established canopy produce

organic buildup, also known as biomass accretion. Accretion produces a net increase

in the substrate, effectively raising the elevation of the swamp floor. It is estimated

that with a healthy freshwater swamp habitat, the study area could produce

8 mm/yr of biomass accretion (Bernard Wood, unpublished data, 2005 through

2009). Accretion could help offset the effects of subsidence and RSLR, thereby

reducing negative impacts and increasing the benefits associated with the proposed

action. Additional discussion on biomass accretion is located in Section 5.2 of this

report.

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Risk of Flooding. According to the H&H modeling it was determined that

all proposed actions would have an insignificant reduction in the stage on the Amite

River and on the ARDC. The modeling also showed an insignificant increase in

stage height within the swamp area, near the proposed openings in the ARDC

dredged material berms. It has also been noted that under existing conditions, the

interior swamp areas tend to flood during high stage events. The proposed plan

features will not restrict flow in the ARDC or in the swamps adjacent to the ARDC.

Therefore there would not be an increase in the risk of flooding within the study

area. Additionally, increased flood risks would not occur for any nearby businesses

and residences as a result of all proposed actions.

Geotechnical Uncertainties. Until a full geotechnical investigation is

performed in the PED phase of the project, uncertainties will exist with the

assumptions made regarding material placement and slope stability. It is assumed

that when material from excavation is placed within the project area, it will be

stable enough to create habitat at an elevation sufficient to sustain bottomland

hardwood tree species. However, if the material does not maintain the required

elevations, a shift in the tree species to be utilized for these plantings will be made

to those suitable for a freshwater swamp. Additionally, the stability of channel and

placement area slopes will not be known until the full results of a slope stability

analysis are completed.

Assumptions. The following assumptions are key to the success of the

project:

• The rainfall-driven conditions of the Amite River watershed will remain

unchanged; therefore, the hydrologic cycles within the ARDC will also

remain unchanged. The current trend suggests conditions will remain

unchanged.

• The net effects of local subsidence and sea level rise will not deviate

significantly from the numbers estimated for this study. This is based on

hydraulic and habitat conditions.

• The conveyance channels would be naturally altered over time but would

remain functional, eventually reaching a state of hydrologic stability.

This is based on existing natural channels in the study area which have

formed under similar conditions.

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3.9 IMPLEMENTATION REQUIREMENTS

3.9.1 Schedule

The approximate LCA ARDC milestone schedule for project implementation is

shown in Table 3.22. A favorable signed Chief’s Report is required by December 31,

2010 to obtain authorized construction funding.

Table 3.22. LCA ARDC Milestone Schedule

Milestone Baseline Date

Final Report August 2010

Division Engineers Notice August 2010

Washington Level Reviews August 2010

State and Agency Review October 2010

Sign Chief’s Report December 2010

ASA(CW) and OMB Review 2011

ASA(CW) Reports to Congress 2011

The remaining requirements for the LCA ARDC FS/SEIS, and modification project

implementation schedule are shown in Table 3.23. Design Considerations were

previously discussed in Section 3.7.2.

Table 3.23. LCA ARDC Modification Project Implementation Schedule

Milestone Baseline Date

Begin Pre Construction Engineering and Design 2010

Initiation of Monitoring Program 2010

USACE and non-Federal sponsor negotiate PPA 2012

Complete Plans and Specifications 2012

Real Estate Acquisition 2012

Award Contract 2012

Construction Start 2012

Complete Construction- Earthwork 2012

Complete 1st Vegetation Planting 2015

Complete 2nd Vegetation Planting 2018

Turnover Project to Local Sponsor 2018

Complete Monitoring Program 2023

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3.9.2 Implementation Responsibilities

This project was authorized for construction by the Water Resources Development

Act of 2007, contingent upon a signed Chief of Engineers Report by December 31,

2010. After a signed Chief’s report, this project would be eligible for construction

funding. The project would be considered for inclusion in the President’s budget

based on national priorities, magnitude of the Federal commitment, economic and

environmental feasibility, amount of local public support, willingness of the nonFederal sponsor to fund its share of the project cost, and the budget constraints that

may exist at the time of funding. Once Congress appropriates Federal construction

funds, the Corps and the non-Federal sponsor would enter into a project

partnership agreement (PPA). This PPA would define the Federal and non-Federal

responsibilities for implementing, operating, and maintaining the project. The

project is expected to begin Pre construction Engineering and Design in late 2010

and begin construction in 2012 (see Table 3.22).

The Corps would officially request the sponsor to acquire the necessary real estate

immediately after signing the PPA. The advertisement of the construction contract

would follow the certification of the real estate. After construction, the Corps’

acceptance from the contractor and notice of construction completion of the project

(or a functional portion of the project) to the non-Federal sponsor would proceed or

be concurrent with the delivery of an O&M manual and as-built drawings. The

estimated schedule for project construction is shown in Table 3.23.

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;

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(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 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 non-Federal 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

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CERCLA regulated materials located in, on, or under lands, easements, or rights-ofway that the Federal Government determines to be necessary for the initial

construction, periodic nourishment, operation, or maintenance of the project;

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 AntiKickback 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

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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.

3.9.3 Cost Sharing

The State of Louisiana, acting through the Coastal Protection and Restoration

Authority of Louisiana (CPRA), will be the non-Federal sponsor for the LCA Amite

River Diversion Canal Modification Project. 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 percent Federal and 50 percent non-Federal. However, the individual elements

have been divided so that each entity had 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 non-Federal sponsor will be higher depending upon their level of

responsibility. CPRA had 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 percent Federal and 35 percent 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. Operation,

Maintenance, Repair, Replacement and Rehabilitation (OMRR&R) of the project

would be a 100 percent CPRA responsibility.

Table 3.24 shows the cost apportionment for the Recommended Plan.

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Table 3.24. Cost Apportionment for the Recommended Plan

Item Federal Non-Federal Total

Construction $3,070,000 $1,380,000 $4,450,000

S&A $261,000 $140,000 $401,000

PED $347,000 $187,000 $534,000

LERDDs $0 $180,000 $180,000

Monitoring $1,930,000 $1,040,000 $2,970,000

Total* $5,610,000 $2,930,000 $8,540,000

S&A – Supervision and Administration (Construction Management).

PED – Planning, Engineering, and Design.

LERRD – Lands, Easements, Rights-of-Way, Relocations, and Disposal Areas.

* Fully funded cost estimate includes interest during construction.

Additionally, project monitoring and any Adaptive Management deemed necessary

will be cost shared at 65/35 for the first 10 years of the period of analysis.

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 non-Federal 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 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

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that that there are limited opportunities for the application of "excess credit" from

other Title VII projects toward these projects.

3.9.4 Environmental Commitments

The USACE, non-Federal sponsor, and all contractors would commit to following all

laws and executive order, and to avoid and minimize adverse impacts to the

environment by the following:

• Employ necessary Best Management Practices (BMPs) to reduce erosion

and sedimentation during construction. The Plans and Specifications

would include such BMPs and erosion control measures as necessary. The

Contractor would be required to develop a Storm Water Pollution

Prevention Plan (SWPPP) that would be coordinated through the

Louisiana Department of Environmental Quality (LDEQ).

• The Contractor would be made aware of any practices or measures need to

be compliant with the Endangered Species Act (ESA).

• The Contractor would be made aware of any practices or measures to

protect cultural resources.

• The USACE and the non-Federal Sponsor agree to maintain coordination

with the U.S. Fish and Wildlife Service (USFWS) and the LDEQ to ensure

compliance with all laws and executive orders.

The Contractor would be prohibited from dumping oil, fuel, or other hazardous

substances and would require that all appropriate sanitation measures are

followed. The Contractor would be to develop a Spill Prevention Control and

Countermeasure plan (SPCC).

3.9.5 Financial Requirements

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 financial analysis

will be conducted to assess the CPRA's capability to financially participate in the

Recommended Plan. A standard cost share percentage of 65 percent Federal and

35 percent non-Federal would be applied to the total first cost of the project. The

35 percent 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 authorized to carry out the study or project.” If the Mineral

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Management Services determines in writing that funds it provides to the nonFederal 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 ARDC project, the non-Federal sponsor

can use those funds toward satisfying its local cooperation for the project, including

the non-Federal sponsor's acquisition of 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.

3.9.6 Views of Non-Federal Sponsor

As demonstrated in its August 9, 2010 letter of support for the LCA6, (Attachment

1) CPRA, the non-federal sponsor, has expressed the desire for implementing the

LCA Amite River Diversion Canal Modification project and sponsoring the project

construction in accordance with the items of local cooperation that are set forth in

the recommendations chapter of this report. In addition, CPRA supports the NER

plan (Alternative 39) since this plan includes all of the most critical areas within

the Maurepas Swamp basin, establishes the greatest amount of hydrologic

connectivity of all of the alternatives, is cost-effective while providing the most

benefits, and is a best-buy plan. However, due to authorized cost limitations in

WRDA 2007, CPRA supports Alternative 33 as the Recommended Plan. CPRA

believes the project warrants additional Congressional authorization to increase

funding and allow the implementation of the NER plan (Alternative 39) to fully

address the Maurepas Swamps ecosystem needs identified in this report.

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

4.1 ENVIRONMENTAL SETTING OF THE STUDY AREA

This section describes the climate, geomorphic and physiographic setting, and the

historic and existing conditions for the following important resources: soils and

waterbottoms, coastal vegetation, wildlife, fisheries, plankton, benthos, essential

fish habitat (EFH), threatened and endangered species (T&E), hydrology (including

flow and water levels, and sedimentation), water quality, recreation, cultural and

historic resources, aesthetics, air quality, socioeconomic and human resources

(including population, infrastructure, employment and income, navigation, oil and

gas resources, utilities, pipelines, commercial fisheries, oyster leases, flood control,

and hurricane protection), noise and Hazardous and Toxic and Radioactive Wastes

(HTRW).

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 Louisiana Coastal Area Amite River Diversion Canal (LCA

ARDC) study area.

4.1.1 Location

The LCA ARDC study area (Figures 1.2 and 1.3) is located along the ARDC in

Ascension and Livingston Parishes, in the vicinity of Head of Island, Louisiana. The

study area is bounded to the north by the old channel of the Amite River, Old River,

Chinquapin Canal and Bayou Chene Blanc; to the east by the Blind River; to the

south by the Petite Amite River and the New River Canal; and to the west by the

Sevario Canal, Ascension Parish flood protection levees, and the Laurel Ridge

Canal.

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

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

(LACPR, 2009). The study area is also subject to periods of both drought and flood,

and the climate rarely seems to truly exhibit “average” conditions.

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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. Historical data from 1899 to

2007 indicate that 30 hurricanes and 41 tropical storms have made landfall along

the Louisiana coastline (NOAA, 2009). The largest recent hurricanes were Katrina

and Rita in 2005, which caused extensive devastation in south Louisiana and some

damage in the study area. Hurricane Gustav, while much smaller and less intense,

caused additional damage in the study area in 2008. Hurricane Ike, which made

landfall in Galveston, Texas in 2008, caused flooding and wind damage in coastal

areas as it passed the LA Coast.

The 1955 USACE Survey of Amite River and Tributaries, Louisiana provides

historical climate and meteorological data for the lower Amite River Basin, which

includes the study area. Average minimum and maximum temperatures and

rainfall, over the period of record (POR), is provided in the survey. The minimum

and maximum temperatures from 1901 through 1953 for Reserve, Louisiana,

located 10 miles from the study area, are 15 and 100 degrees Fahrenheit,

respectively. The average temperature for the same POR is 70 degrees Fahrenheit.

The survey also identified 10 rainfall stations in the lower Amite River Basin (a

subset of the temperature stations with approximately the same PORs), also

ranging from 10 to 70 miles from the study area. Minimum and maximum annual

rainfall values for Reserve were reported as 34.1 and 84.3 inches, respectively. The

average rainfall for Reserve during the same POR was 61.6 inches.

4.1.3 Geomorphic and Physiographic Setting

The geomorphic and physiographic setting is technically significant because geologic

conditions can place constraints on the nature, design, or location of the proposed

action, as well as determine the impacts that the proposed action would have on

other important resources.

The study area is located in the Maurepas Basin, a component of the Lake

Pontchartrain Basin, which is located near the southern terminus of the Mississippi

Alluvial Plain physical province. The most significant geologic features in the basin

are Lakes Maurepas and Pontchartrain. These lakes occupy a portion of the St.

Bernard Delta complex, one of the oldest deltaic complexes within the Mississippi

Deltaic Plain Region. The St. Bernard Delta complex formed in what was then

Pontchartrain Bay, enclosing a portion of the bay to form Lake Pontchartrain. The

Open-File Report 98-36 (1998) describes the St. Bernard Delta complex as a distinct

physiographic unit, formed by Mississippi River deposits between 700 and 4,700

years ago. The majority of the remaining surface features within the St. Bernard

Delta complex are comprised of inland swamp, tidal channels, shallow lakes and

bays, natural levee ridges along active and abandoned distributaries, sandy barrier

islands, and beaches.

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The St. Bernard Delta complex began receiving Mississippi River deltaic sediments

from the middle to late Holocene. The first deltaic deposits to enter the area were

homogenous prodelta clays. This was followed by the deposition of interdistributary

bay deposits as the Mississippi River and its distributaries prograded. The deposits

were finer sediments (silty clay and clay) that were transported away from the

distributary channel and settled out of suspension as interdistributary deposits.

Holocene deposits in the St. Bernard Delta complex typically overlay Pleistocene

alluvial terrace deposits of fine grained sands and silts derived from alluvium

deposited by the proto-Mississippi and other coastal river systems during recent sea

level lowstand intervals. Holocene and Pleistocene deposits are underlain by

approximately 34,000 feet (ft) of sediment and sedimentary rock. Sandstone,

siltstone, and claystone account for virtually all the sedimentary rocks. These

sediments record the outward progression of the Gulf Coastal Plain, and in the case

of Pleistocene sediments, the outward building of the Mississippi and protoMississippi River Complex.

Construction of the Amite River and Tributaries (1956) flood control project, which

includes the ARDC, has impacted the natural geomorphology and hydrology of the

St. Bernard Delta complex. Hydrologic analyses within the study area indicate that

the ARDC and its associated dredged material berms have hydrologically isolated

the study area, thereby preventing the adjacent bald cypress-tupelo swamp habitat

from receiving nutrient and sediment-laden floodwaters during high channel flow

events and have prevented the adjacent swamps from draining during low channel

flow events in the lower Amite River system. Further details behind the

geomorphic setting related to the LCA ARDC project are located in Appendix L of

the report. Additionally, biomass accretion rates are discussed in Sections 2.3.3.2

and 5.2 of the report.

4.2 SIGNIFICANT RESOURCES

4.2.1 Soils and Waterbottoms

Soils are institutionally significant because of the Center for Environmental Quality

memorandum of August 11, 1980, entitled “Analysis of Impacts on Prime or Unique

Agricultural Lands in Implementing the National Environmental Policy Act

(NEPA);” EO 11990 – Protection of Wetlands; and Agriculture and Food Act of 1981

(Public Law 97-98) containing the Farmland Protection Policy Act (FPPA) (Public

Law 97-98; United States Code [U.S.C.] 4201 et seq.). This resource is technically

significant because it is a critical element of coastal habitats, supports vegetation

growth and benthic productivity, and influences the types of land use within a given

area. This resource is publicly significant because of the high value the public

places on wildlife and fisheries supported by the soils in the area.

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Soils and waterbottoms are institutionally significant because of the NEPA of 1969;

the Coastal Zone Management Act; and the Estuary Protection Act. They 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). Waterbottoms are publicly significant because of their

habitat value to members of the epibenthic community (e.g., oysters, mussels, etc.)

that utilize estuarine waterbottoms and provide commercial and recreational

fisheries.

4.2.1.1 Soils

Deltaic processes have played a significant role in the types of soil present in

the LCA ARDC study area. The dynamic and episodic deltaic building processes

alternate between periods of seaward progradation of deltas (regressive deposition)

and the subsequent landward retreat of deltaic headlands as deltas are abandoned,

reworked, and submerged by marine waters (transgressive deposition). The types

of soils present today in much of the LCA ARDC study area are characterized by the

depositional environments associated with both phases of the deltaic cycle.

Historic Conditions. There has been a conversion of 1,600 acres of

freshwater swamp habitat to marsh and open water in the Amite and Blind River

mapping units between 1932 and 1990 (Louisiana Coastal Wetlands Conservation

and Restoration Task Force [LCWCRTF] and Wetland Conservation and

Restoration Authority [WCRA], 1999).

Existing Conditions. National Resource Council (NRC) data

indicate that 19 soil types are found within the LCA ARDC study area (Figures 4.1

and 4.2, Natural Resources Conservation Service [NRCS], 1976, 1991). Soils within

the LCA ARDC study area are typically hydric clays or mucks that are frequently or

continuously flooded (NRCS, 1976, 1971). Soils in the Barbary series comprise a

majority (62 percent) within the LCA ARDC study area, and substantial quantities

of soils within the Maurepas series (12 percent) are also present.

Soil loss is continuing due to natural and man-made causes,

particularly in the Barbary, Fausse, and Maurepas soils. As a result, swamp and

wetland forests have deteriorated and become increasingly stressed. Die back of the

swamp vegetation has contributed to the conversion to freshwater marsh. As marsh

fragments, small islands of floating marsh can develop. Floating marsh (flotant) is

vulnerable to degradation and is considered the most fragile, with respect to

catastrophic storm events, of all marsh types. Due to degradation and decreased

productivity, soil accretion is insufficient to offset regional subsidence and the

degraded swamp habitat is consequently susceptible to conversion to fresh marsh or

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Land Use/Land Cover Data: USGS Louisiana Gap Analysis Project, 1998

Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: November 2009Scale:Source: USDA/USGS/GEC

LAND USE/LAND COVER MAP

Map ID: 27850108-1849

LITTLE BAYOU CHENE BLANC

BAYOU CHENE

B

L

A NC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

NEW RIVER CANAL

PETITE AMITE RIVER

CHINQUAPIN CANAL

BAYOU A

T N O NI E

FLAT

LAKE

PETITE AM TI E R VI

RE

BAYOU CHENE BLANC

OLD RIVE R

BAYOU PI ERRE

BLAC K LAKE

HEATH BAYOU

1:85,000

0 0.5 1 1.5 2

Miles

Legend

Study Area

Land Use/Land Cover Type

Agriculture-Cropland-GrasslandDense Pine ThicketFresh MarshUpland BarrenUpland Forest-DeciduousUpland Forest-EvergreenUpland Forest-MixedUpland Scrub/Shrub-EvergreenUpland Scrub/Shrub-MixedVegetated UrbanWetland Forest-DeciduousWetland Forest-MixedWetland Scrub/Shrub-DeciduousWetland Scrub/Shrub-EvergreenWetland Scrub/Shrub-MixedWater

Figure: 4.1

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Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: November 2009Scale:Source: USDA/NRCS/GEC

SOILS MAP

Figure: 4.2Map ID: 27850108-1848

LITTLE BAYOU CHENE BLANC

BAYOU CHENE

B

L

A

N C

BLIND RIVER

AMITE RIVER DIVERSION CANAL

NEW RIVER CANAL

PETITE AMITE RIVER

CHINQUAPIN CANAL

BAYOU AN

OT

NI E

FLAT

LAKE

PETITE AM TI E RI V

RE

BAYOU CHENE BLANC

OLD RIVE R

BAYOU PIERRE

BLAC K LAKE

HEATH BAYOU

1:90,000

0 0.5 1 1.5 2

Miles

Note: Prime Farmland Soilsalso denoted by bold font

Legend

Study Area

Soil Type

At-Aquents,dredgedBA-Barbary association/Barbary muckCn-Calhoun silt loam, occasionally floodedCy-Colyell-Springfield silt loams, frequently floodedFA-Fausse associationFG-Fausse-Galvez associationFo-Foley-Deerford complexMA-Maurepas muckMt-Myatt fine sandy loamNa-Natalbany silty clay loam, frequently floodedSf-Sharkey clay, frequently floodedW-Water

Prime Farmland

Ca-Calhoun silt loamCo-Colyell silt loam, 1-3% slopeEs-Essen silt loamOe-Olivier silt loam, 0-1% slopeOr-Olivier silt loam, 1-3% slopeSa-Sharkey silty clay loamSc-Sharkey claySp-Springfield silt loam

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open water. According to guidance form EC-1165-2-211, the subsidence rate for the

project area has been calculated to be 7.5 mm/yr (USACE 2009).

Prime and Unique Farmlands. In an effort to identify the extent and

location of important farmlands, NRCS, in cooperation with other interested

Federal, state, and local government organizations, has inventoried land that can

be used for the production of the nation’s food supply. The United States

Department of Agriculture (USDA) defines prime farmland soil as land with the

best combination of physical and chemical characteristics for producing food, feed,

forage, fiber, and oilseed crops that is available for these uses. Prime farmland

generally has an adequate and dependable supply of moisture from precipitation or

irrigation, a favorable temperature and growing season, acceptable acidity or

alkalinity, an acceptable salt and sodium content, and few or no rocks (USDA 2006).

Some soils identified as prime farmland require measures that overcome hazards or

limitations such as flooding or excess wetness or drought.

Unique farmland is land other than prime farmland that is used for

the production of specific high-value food and fiber crops, such as citrus, tree nuts,

olives, cranberries, and other fruits and vegetables (USDA NRCS, 1993). It has the

special combination of soil quality, growing season, moisture supply, temperature,

humidity, air drainage, elevation, and aspect needed for the soil to economically

produce sustainable high yields of these crops when properly managed. The water

supply is dependable and of adequate quality. Nearness to markets is an additional

consideration. Unique farmland is not based on national criteria, and commonly

occurs in areas where there is a special microclimate. Additional Farmlands of

statewide importance nearly meet the criteria for prime farmland, and economically

produce high crop yields when treated and managed according to acceptable

farming methods.

A recent trend in land use in some areas has been the loss of prime

farmland to industrial and urban areas. The loss of prime farmland to other uses

puts pressure on marginal lands, which generally are more erodible, susceptible to

drought, less productive, and cannot be easily cultivated. As a result of a

substantial decrease in the amount of open farmland, the FPPA was put forth by

Congress. In the statement of purpose, Federal programs which contribute to the

unnecessary and irreversible conversion of farmland to nonagricultural uses would

be minimized. It follows that Federal programs shall be administered in a manner

that, as practicable, would be compatible with state, local government, and private

programs and policies to protect farmland.

Eight soils within the LCA ARDC study area are classified as prime

farmland. These soils (Calhoun silt loam; Colyell silt loam; Essen silt loam; Olivier

silt loam, 0-1 percent slopes; Olivier silt loam, 1-3 percent slopes; Sharkey silty clay

loam; Sharkey clay; Springfield silt loam) comprise a total of approximately 749

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acres (three percent) of soils within the LCA ARDC study area (See Figure 4.2).

Prime farmland soils within the LCA ARDC study area are generally confined to

agricultural areas in the vicinity of LA Highway 22 (LA-22).

4.2.1.2 Waterbottoms

Historic Conditions. Historically, swamp waterbottoms in the LCA

ARDC study area were typically subjected to flooding and drying events.

Construction of the ARDC (1956) and the Chinquapin Canal (constructed in the

early 1960s) increased the amount of available waterbottoms. However, sidecast of

the dredged material from constructing the ARDC and Chinquapin canal has

restricted hydrologic connectivity thereby impounding and permanently flooding

large portions of the swamp habitats in the LCA ARDC study area.

Swamps have been shown at times to be both sources and sinks of

nutrients, particularly nitrogen. Phosphorus, however, is typically the limiting

nutrient which is attributed to excessive algal growth (blooms). Little phosphorus

appears to be retained in swamp vegetation, but instead is retained in the

sediments. As long as sediment mobilization remains low, phosphorus export

should remain low (Mitsch and Gosselink, 2000). Nitrogen is largely reduced by

denitrification, but can also undergo substantial reductions via burial in subsiding

sediments (Lane et al., 2003). According to Mitsch and Gosselink (2000), organic

matter is utilized primarily through detrital pathways, but decomposition can be

impeded by anaerobic conditions. Mitsch and Gosselink (2000) point out that little

detritus material is exported from the still water or slow-flowing swamps.

However, detritus export can be significant from lake edge and river swamps.

Existing Conditions. Waterbottoms in the LCA ARDC study area

are associated with the existing waterways and channels, including the ARDC,

bayous, canals, and creeks, and are also in open water areas within the swamp.

Portions of the swamp are impounded by dredged material berms along the ARDC

and maintain higher-than-normal water levels.

4.2.2 Hydrology

This resource is institutionally significant because of NEPA; Clean Water Act

(CWA); 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 EO 11988 Floodplain

Management. This resource is technically significant because civil works water

resources development projects typically impact (positively or negatively) the

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interrelationships and interactions between water and its environment. This

resource is publicly significant because the public demands clean water, hazard-free

navigation, and protection of estuaries and floodplains.

The LCA ARDC study area is located within the Pontchartrain Basin, a 9,700-

square-mile drainage basin in southeastern LA. Three major estuarine lakes,

Lakes Maurepas, Pontchartrain, and Borgne, each form a subbasin of the greater

Pontchartrain Basin. The LCA ARDC study area is located within the Maurepas

subbasin and the Amite River and Blind River watersheds. The combined Amite

River and Blind River watersheds are approximately 2,200 square miles. Most of

the LCA ARDC study area is in the Blind River watershed and most of this

watershed is the Lake Maurepas swamp. Storm water runoff in the LCA ARDC

study area is dominated by the Amite River. The Amite River watershed is

approximately 1,842 square miles and a third of this watershed is in the State of

Mississippi. Additionally, the LCA ARDC study area is hydrologically independent

of the LCA Small Diversion at Convent/Blind River study area.

4.2.2.1 Flow and Water Levels

Historic Conditions. Historically, hydrology within the LCA ARDC

study area was dominated by overbank flows from the Mississippi and Amite

Rivers. The construction of flood control projects, most notably the AR&T (1956)

project, which includes the ARDC, largely isolated bald cypress-tupelo swamp

habitat within the LCA ARDC study area from natural waterbodies and effectively

ended overbank flooding from the Mississippi and Amite Rivers. The LCA ARDC

study area is a rural and relatively lightly inhabited coastal wetland forest area

that contains potable water resources. Sources of fresh groundwater in the LCA

ARDC study area and vicinity include the Chicot Equivalent Aquifer, the

Evangeline Equivalent Aquifer, and the Jasper Equivalent Aquifer.

Historically, hydrologic conditions within the LCA ARDC study area

were dominated in the north and west by the Amite River, in the south by overbank

flow from the Mississippi River, and in the east by tidal influence from Lake

Maurepas. Periodic flooding of the Amite River and/or Mississippi River resulted in

the inundation of the LCA ARDC study area. Flooding occurred annually, with peak

water elevations in the late spring or early summer. As floodwaters receded, surface

waters in the LCA ARDC study area were conveyed eastward via sheet flow until

they were received by Bayou Chene Blanc or the Blind River, by which they were

conveyed to Lake Maurepas. Further hydrology and hydraulic information is

provided in Appendix L.

Implementation of flood control projects, beginning in the early 19th

century and culminating in the Mississippi River and Tributaries (MR&T) (1928)

and AR&T (1956) Federal flood control projects disrupted the natural hydrologic

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regime within the LCA ARDC study area. River channelization and levee

construction reduced overbank flooding in the LCA ARDC study area, which in turn

reduced the influx of floodwaters bearing high volumes of nutrients and sediment

that are essential for biomass production and soil accretion. Additionally, the

placement of dredged material along either side of the ARDC disrupted sheet flow

within the LCA ARDC study area and prevented the drainage of the swamp during

intervals of low surface flow (Shaffer et al., 2006). These dredged material berms, in

conjunction with other constructed improvements, such as the relict railroad grade

that crosses the eastern LCA ARDC study area from north to south, permanently

impounded some of the swamps within the LCA ARDC study area.

Sea level Rise. Eustatic sea level refers to the global fluctuations in

sea level primarily due to changes in the volume of major ice caps and glaciers, and

expansion or contraction of seawater in response to temperature changes. Past

studies based on worldwide tide gauges estimate the rate of eustatic sea level rise at

1.2 mm/yr (Gornitz et al., 1982). Additional studies have estimated between 3 to

5 mm/yr (Penland et al., 1990). More recent studies have predicted an increase in

this rate to 1.7 mm/yr for the next 100 years due to climate change (EC 1165-2-211).

The entire Louisiana coastal zone is experiencing relative sea level

rise, the net effect of eustatic sea level rise coupled with numerous processes that

result in a downward movement of the land surface relative to sea level. Vertical

land movement along the Louisiana coast is controlled by several major factors,

including compaction and faulting. Past studies have indicated a relative sea level

rise rate from 5 to 9 mm/yr within the Maurepas Swamp area (Penland et al., 1990).

In addition to eustatic sea level rise, EC 1165-2-211 provides

procedures for incorporating vertical land movement into the analysis. Relative sea

level rise (RSLR) is obtained by incorporating the eustatic sea level rise with

vertical land movement. A historic rate considered to be representative of the LCA

ARDC study area is calculated using the West End at Lake Pontchartrain gage

(85625). Daily stage data over the period 1959 to 2009 indicate a rate of 9.20 mm/yr

(0.0302 ft/yr; see Figure 4.3). The standard error of the linear trend line is 0.65 ft.

Figure 4.3. Plot of Historic Rate from Daily Stage Data

West End at Lake Pontchartrain (85625) Historical Stage Data y = 0.0302x - 57.963

-2

-1

0

1

2

3

4

5

6

7

8

1956195719581959196019611962196319641965196619671968196919701971197219731974197519761977197819791980198119821983198419851986198719881989199019911992199319941995199619971998199920002001200220032004200520062007200820092010201120122013

Stage (feet)

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Existing Conditions. The LCA ARDC study area is located within

the Lake Maurepas watershed of the Pontchartrain Basin. The principal hydrologic

influence on the basin is that of Lake Maurepas. Surface water flow within the

basin is generally from west to east to Lake Maurepas during most normal

conditions. However, strong east winds can push water from Lakes Pontchartrain

and Maurepas into the Lower Amite River system (Hsu et al., 1997). Principal

surface flow conduits in the LCA ARDC study area include the ARDC, the Amite

and Petite Amite Rivers, and Blind River, into which the flow from other

waterbodies is ultimately received and conveyed to Lake Maurepas. From Lake

Maurepas surface waters are conveyed eastward through Pass Manchac, North

Pass, or gaps in the Manchac Land Bridge to Lake Pontchartrain, from which they

are conveyed eastward to the Gulf of Mexico via Chef Menteur Pass or the Rigolets

and Lake Borgne.

Hydrologic flow patterns in the southwestern Maurepas Swamp were

modeled in support of Coastal Wetlands Planning, Protection, and Restoration Act

(CWPPRA) Project PO-29, Mississippi River Reintroduction into Maurepas Swamp

(Day et al., 2004; URS, 2007). Physical hydraulic and hydrologic processes in the

Maurepas Swamp, including channel flow, propagation of tidal signals, overbank

flow, flow through bank gaps, and swamp circulation, were assessed under a variety

of conditions during this modeling effort. The results of these investigations

indicate that Lake Maurepas exerts a significant influence on stage levels within

the lower Amite River and Blind River systems.

The swamp habitat along the left descending bank of the ARDC in

subunits NE-1 and NE-2 is impounded (Shaffer et al., 2006) (Figure 4.4). Figure 4.5

presents water surface elevation for a gages within NE-1, NE-2, along with three

USGS gauges located within or near the study area. A map depicting the location of

these gauges may be found in the H&H report in Appendix L, Section 2, Figure 2.2

of this report. During the study period, water levels within this area never receded

below 2.2 ft above sea level; even during periods in which water levels within the

canal receded below this level.

Within the eastern portion of the LCA ARDC study area, the swamps

adjacent to the right descending bank of the ARDC exhibit a lack of hydrologic

connectivity as well. The resulting lack of water flow between the ARDC and the

adjacent swamp inhibits the exchange of sediments and nutrients within the

swamp, which is vital to tree regeneration and growth.

Swamp impoundment does not appear to occur in the western portion

of the LCA ARDC study area. Numerous drainage culverts were observed within

the dredged material berms in these areas during field investigations, particularly

in the portions of the LCA ARDC study area located in Ascension Parish.

Additionally, several small gaps were constructed in the dredged material berms in

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this area, and the confluence of Bayou Pierre with the ARDC provides additional

hydrologic exchange between the ARDC and the adjacent swamp. Most of these

hydrologic conduits are located northwest of the LA Highway 22 Bridge.

Figure 4.4. Hydrograph of Water Levels Obtained from Louisiana

Department of Natural Resources (LDNR) Gauges in

the LCA ARDC Study Area (Source: Shaffer et al., [2006])

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Figure 4.5. Water Surface Elevations at the North Swamp at the Railroad

Grade and North Swamp at the Bridge in North American

Vertical Datum (NAVD) 88(2006.81) and

Three U.S. Geological Survey (USGS) Gauges

4.2.2.2 Sedimentation and Erosion

Sediment quality is defined as the suitability of the habitat for supporting

designated uses, including, but not limited to, benthic fauna and emergent wetland

plants. Storm events, flowing water, and other factors can potentially re-mobilize

sediments (Louisiana Department of Environmental Quality [LDEQ], 2007).

Aquatic sediments are essential in maintaining the structure (assemblage of

organisms) and function (processes) of aquatic ecosystems (LDEQ, 2007). Sediment

quality is significant because sediments support community productivity (LDEQ,

2007). The productivity of green plants, algae, and bacteria build the foundation of

food webs upon which higher aquatic organisms depend. Sediments provide

essential habitats for epibenthic (live on sediments) and infaunal (live in sediments)

invertebrates and demersal fish, which represent important food sources for

amphibians, reptiles, fish, birds, and mammals (LDEQ, 2007). Additionally, many

fish and amphibian species utilize sediments at stages in their life cycles for the

purposes of spawning, incubation, refuge, and over-wintering (LDEQ, 2007).

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Historic Conditions. In addition to contributions from erosion and

tropical storms, the Amite River is, and the Mississippi River and the Amite River

were, the primary sources of sediment input into waterbodies within the LCA

ARDC study area. The northern 30 miles of the Amite River in Louisiana, i.e., from

the Mississippi state line to LA hwy 37 in Grangeville, is recognized as one of 15

waterbodies impaired by excess sediments in Louisiana (LDEQ, 2006). Fish and

wildlife habitat has been directly degraded with significant loss of shoreline and

aquatic habitat in this reach. This degradation is believed to have been caused by

urbanization, sand and gravel mining, erosion, shallower water, faster flow, higher

water temperature, increased turbidity, and agricultural/forestry practices over the

last 50 years (LDEQ, 2006). This sediment impairment in the river has caused

higher river stages downstream. The soil erosion rate for the Upper Amite River

Basin has been calculated to be 5.42 ton/acre/year, producing a sediment load of

0.103 kg/m3 to the Amite River (Mishra, 2005). There is a decreased redistribution

of sediment into some of the swamps due to the dredged material berms of the

ARDC.

Existing Conditions. The Blind River, which bounds the LCA ARDC

study area to the southeast is the receiving water for the ARDC flow before

discharging to Lake Maurepas, is listed on the 2006 303(d) list of impaired

waterbodies as being impaired by excess sediments from the source to the outfall at

Lake Maurepas (LDEQ, 2006). Sediment Total Maximum Daily Loads (TMDL), as

well as a nutrient TMDL, is also required by the U.S. Environmental Protection

Agency (USEPA) to be developed by 2011 for the Blind River.

To date, a limited amount of sediment samples within the ARDC and

other waterbodies in the LCA ARDC study area (proximal upstream waterbodies)

have been collected for analysis. The USGS is currently collecting data on both

suspended sediments and bed sediments at five sites along the Amite River;

however, this data will not be available until late 2010 (Dennis Demcheck, USGS,

personal communication, April 10, 2009).

The USGS conducted a study in 1998 to examine the occurrence and

distribution of trace elements and organic compounds in southern LA fishes and

streambeds, including fine-grained samples and deep core sediment samples (bulk

samples) (Skrobialowski, 2002). One of the sites at which sediment sampling was

conducted for this study is located on the Amite River near Port Vincent,

approximately 5.5 miles upstream of the ARDC.

While limited sediment sampling data is available at this time, LDEQ

has an ongoing program

(http://www.deq.louisiana.gov/portal/default.aspx?tabid=2204) to resample

sediments of all waterbodies currently identified as impaired due to the presence of

metals, using improved sampling methods to minimize sample contamination. In

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the most recent (2006) 303(d) list

(http://www.epa.gov/region6/water/npdes/tmdl/303d/la/epa-finallist_2006.pdf) of impaired waterbodies, all reaches of the Amite River, the Blind

River, and the ARDC are listed as impaired for the Fish and Wildlife Propagation

designated use because of mercury. While this was originally determined by LDEQ

using fish tissue sampling, LDEQ would likely conduct sediment sampling for

confirmation of this data prior to the 2011 TMDL deadline.

4.2.2.3 Water Use and Supply

Historic Conditions. Water use within the LCA ARDC study area is

primarily limited to public drinking water. The Louisiana Department of

Transportation and Development (LA DOTD) online registry of water wells

(http://www.dotd.louisiana.gov/intermodal/wells/) identifies nine registered

water wells owned by Diversion Water Company, L.L.C. (DWC) in the vicinity of the

ARDC within the LCA ARDC study area. The LA DOTD water well registry also

identifies 33 privately owned water wells in the LCA ARDC study area (primarily in

the vicinity of LA-16 and LA-22). Water provided to the LCA ARDC study area by

French Settlement Water Company, Inc. (FSWC) is obtained from a well north of

the LCA ARDC study area in Head of Island along LA-22. Department of

Agriculture (DOA) Section 10/404 Permits for existing waterfront developments on

the left descending bank of the ARDC identify the locations of two pump stations

associated with water wells at approximately 1.0 and 3.3 miles east of the Petite

Amite River. Proposed new development projects on the south ARDC bank east of

the Petite Amite River would receive water service from DWC. No surface drinking

water system intake locations were identified in the vicinity of the LCA ARDC

study area. Further water use and supply information is provided in Appendix L.

Existing Conditions. Water supply in the LCA ARDC study area is

primarily obtained from the local Gonzales-New Orleans aquifer (LDEQ, 2007).

However, a small number of wells in the LCA ARDC study area have local aquifer

sources (identified in the LA DOTD well registry) of the 600 foot sand of Baton

Rouge aquifer, the shallow sand (less than 400 foot) of Baton Rouge aquifer, and the

Norco (Geismar) aquifer. All of these local aquifers are part of the Chicot

Equivalent aquifer system. Conversion of swamp to open water reduces the water

purification function of forested wetlands.

4.2.2.4 Groundwater

Historic Conditions. Sources of fresh groundwater in the LCA

ARDC study area and vicinity include the Chicot Equivalent Aquifer, the

Evangeline Equivalent Aquifer, and the Jasper Equivalent Aquifer. Rivers and

streams within the LCA ARDC study area exhibit a meandering regime rather than

the entrenched or braided regimes observed in areas with higher gradients.

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Common geomorphologic features in this regime include crevasse splays, point bars,

floodplains, abandoned channels, abandoned courses, and backswamps/flood basins.

Backswamp/flood basin features are predominant in the vicinity of the LCA ARDC

study area. Further groundwater information is provided in Appendix L

(Engineering Appendix). Generally, groundwater has not been a major concern in

the LCA ARDC study area.

Existing Conditions. Groundwater is not a major issue of concern in

the LCA ARDC study area. The LA DOTD online registry of water wells identifies

five registered water wells within the LCA ARDC study area and four registered

wells within the one-mile buffer of the LCA ARDC study area boundary. Four of

the wells within the LCA ARDC study area are in the Chinquapin community;

these four wells range in depth from 300 to 445 ft below ground surface (bgs). Two

of the wells are owned by the FSWC and two are owned by private citizens. The

fifth well within the LCA ARDC study area is a 500-foot bgs well owned by DWC; it

is located on the left descending bank of the ARDC. A 440-foot bgs well is located

within the one-mile buffer on the left-descending bank of the Chinquapin Canal. A

495-foot well owned by DWC, is located within the one-mile buffer on the right

descending bank of the ARDC. Two wells are located on the right descending back

of the Blind River near its confluence with the ARDC: one 719-foot well registered

to LA Public Works, and one 240-foot well registered to Gulf Engineers.

4.2.3 Water Quality and Salinity

This resource is institutionally significant because of the NEPA; the CWA; the

Coastal Zone Management Act; and the Estuary Protection Act. This resource is

technically significant because water 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. Further water quality

information is provided in Appendix L (Engineering Appendix).

The Clean Water Act of 1977 established a process for states to develop information

on the quality of their water resources. Section 305(b) requires that each state

develop a program to monitor the quality of its surface and groundwater and

prepare a report describing the status of its water quality. Section 303(d) requires

states to list impaired waterbodies where water quality standards are not met and

designated uses are not fully supported, and to develop a TMDL for those

waterbodies. Louisiana waterbody subsegments, their designated uses, and

numerical water quality standards are identified in Louisiana Administrative Code

Title 33, Part IX, Subpart 1, Chapter 11, Section 1123 (LAC 33:IX.1123). The

LDEQ Water Quality Inventory Integrated Report is the current form of biennial

reporting of the status of LA waters. The 2008 Final Draft Water Quality Inventory

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Integrated Report summarizes the monitoring data that characterizes the quality of

waters in the vicinity of the ARDC. The Final Draft has not yet been promulgated.

Section 303(d) of the Clean Water Act requires states to identify and list waterbody

segments where water quality standards are not met and designated uses are not

fully supported. The determination of the use support is based on specific guidance

provided by the USEPA. A waterbody may fall within one of three use support

categories depending on the percent of measurements for any one physical or

chemical parameter that exceeds the state’s numerical water quality standards.

These categories include fully supporting, partially supporting, and not supporting.

In the case where more than one parameter defines a designated use, support for

each designated use is defined by the poorest performing parameter.

A draft Total Maximum Daily Load (TMDL) has been submitted by the Louisiana

Department of Environmental Quality (LDEQ) and proposes a 60 percent reduction

in non-point source (NPS) load within the ARDC in order to achieve current water

quality standards. However, the LDEQ is in the process of conducting an

ecoregional use attainability analysis that they suspect will modify the water

quality standard such that the required NPS load reduction will be reduced to

25 percent.

4.2.3.1 Water Quality

Historic Conditions. Historic and current water quality issues for

rivers and streams in coastal Louisiana include the transport of nutrients,

pesticides, synthetic organic compounds, trace elements, suspended sediment, and

bacteria. The LA Department of Health and Hospitals coordinates with the LDEQ,

the Louisiana Department of Wildlife and Fisheries (LDWF), and the LA

Department of Agriculture and Forestry to issue waterbody advisories aimed at

protecting the public’s health.

Human developments along the ARDC, Amite and Blind Rivers have

begun to affect water quality. The ARDC northeast of Sorrento is listed as impaired

for mercury (http://www.epa.gov/region6/water/npdes/tmdl/303d/la/epa-finallist_2006.pdf). The LCA ARDC study area falls within two LDEQ-defined

waterbody subsegments. LDEQ waterbody subsegment 040402 is comprised of 10

square miles identified as the ARDC. The designated uses as assigned in LAC

33:IX.1123 for this subsegment are primary contact recreation (PCR), secondary

contact recreation (SCR), and fish and wildlife propagation (FWP). LDEQ’s 2004

Integrated Report listed subsegment 040402 as being fully supported for the PCR

and SCR uses. The FWP use was identified as not supported because of nutrients

and dissolved oxygen (DO)

(http://www.epa.gov/region6/water/npdes/tmdl/303d/la/epa-finallist_2006.pdf). Suspected sources were unknown. LDEQ’s 2006 Integrated Report

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listed subsegment 040402 as being fully supported for the PCR and SCR uses. The

FWP use was identified as not supported

(http://www.epa.gov/region6/water/npdes/tmdl/303d/la/epa-finallist_2006.pdf) because of chlorides and mercury. Suspected sources included

atmospheric deposition for mercury, and site clearance (i.e., land development or

redevelopment) and drought-related impacts for chloride. Data collected in 2001

were used for both the 2004 and 2006 assessments.

Existing Conditions. Human developments result in wastewater

and polluted runoff from nearby urban areas. The continued conversion of swamp

habitat to marsh and open water reduces natural filtration of water. LDEQ’s 2008

Final Draft Integrated Report lists subsegment 040402 as being fully supported for

the PCR and SCR uses. The FWP use is identified as not supported because of

chlorides, total dissolved solids (TDS), and mercury. Suspected sources include

atmospheric deposition for mercury, site clearance (i.e., land development or

redevelopment) and drought-related impacts for chloride. The TMDL for the

segment are scheduled to be completed by 2011

(http://www.deq.state.la.us/portal/

tabid/130/Default.aspx).

The LDEQ 2008 Final Draft Integrated Report lists subsegment

040403 as being fully supported for the PCR, SCR, and Outstanding Natural Water

Resource (ONWR) uses. Data collected from 2006 were used for the 2008

assessment.

4.2.3.2 Salinity Regimes

Historic Conditions. Recent studies have reported that mean

monthly salinities in the Lake Maurepas Basin have increased 2-3 parts per

thousand (ppt) in comparison to data collected between 1955 and 1981 (USACE,

2004). The ARDC and the Blind River are two of the three main sources of

freshwater input into Lake Maurepas. Salinity data from these two rivers has only

been collected on a regular basis since the year 2000; therefore, it is difficult to

determine whether the river systems have been impacted by the saltwater influence

observed in the lake.

The construction of the ARDC resulted in the impounding of higher

saline waters, thus increasing soil salinities. The dredged material berms of the

ARDC prevent the flushing of these saline waters by the normal headwater event

that follows tropical storms. This lack of flushing and impoundment of saline water

leads to the continued degradation of the swamp habitat.

Existing Conditions. Elevated salinities caused by impoundment of

storm-driven higher-salinity waters and the subsequent absorption of salt into the

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substrate likely contribute to the degradation of the forested swamp and its

eventual conversion to marsh and ultimately open water (Shaffer et al., 2006).

Salinity data were collected at LDEQ stations 0268 on the ARDC and 0243 on the

Blind River in 2006. Data at station 0243 were collected every month except

August, September, and October. One salinity data point was collected in

December 2001. Data were collected from 0268 in January, March, June, and

November of 2006. LDEQ salinity data are summarized in Table 4.1.

Table 4.1. LDEQ Salinity in ppt

Date

sampled

Salinity by LDEQ

Station

0268

(ARDC)

0243

(Blind

River)

12-11-01 --- 0.1

1-10-06 0.1 0.1

2-7-06 --- 0.1

3-7-06 0.2 ---

3-21-06 --- 1.1

4-18-06 --- 0.2

5-2-06 --- 0.1

6-13-06 0.3 1.9

7-31-06 --- 0.1

11-16-06 0.1 ---

12-19-06 --- 0.1

Source: LDEQ, 2009.

Although the data are extremely limited, the salinity at the Blind

River station (0243) was higher than at the ARDC station (0268) when sampled on

the same day in June 2006 (LDEQ 2009). The mean salinity at Station 0268 in

2006 was 0.175 ppt; the mean salinity at Station 0243 in 2006 was 0.462 ppt,

indicating that in 2006 the Blind River station was slightly more influenced by salt

water than the ARDC station. Day et al. (2004) determined mean salinity in the

Blind River study to be 0.144 ppt in the interval 2002-2003.

Salinity data from the Coastwide Reference Monitoring System

(CRMS) stations are summarized in Table 4.2. The mean salinity of the Blind River

stations is similar to that calculated from 2006 LDEQ data. Salinities at the Blind

River surface water stations are nearly identical when plotted by monthly means

(Figure 4.6). Although the mean concentration of the marsh well’s salinity is

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Mean monthly salinities

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Sep

Oct

NovDec

Jan

Feb

March

Apr

May

June

July

AugSep

Oct

NovDec

Jan

Feb

March

Apr

May

June

July

Aug

2007 - 2009

ppt

CRMS0008-W01

CRMS0061-H01

CRMS5845-H01

CRMS0038-H01

similar to that in the Blind River, the range of data is much narrower than that

recorded for the Blind River, and the monthly averages trend differently.

Table 4.2 CRMS Salinity Data Summary in ppt

(http://dnr.louisiana.gov/crm/coastres/monitoring.asp)

Station

Salinity

Mean Low High

CRMS0061-H01 0.34 0 2.38

CRMS0038-H01 0.44 0 2.15

CRMS5845-H01 0.42 0 2.77

CRMS0008-W01 0.48 0.13 0.86

Figure 4.6. Mean Monthly Salinities from Four

CRMS Stations in the Area

(http://dnr.louisiana.gov/crm/coastres/monitoring.asp).

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4.2.4 Air Quality

This resource is institutionally significant because of the Clean Air Act of 1963, as

amended, and the LA Environmental Quality Act of 1983, as amended. Air quality

is technically significant because of the status of regional ambient air quality in

relation to the National Ambient Air Quality Standards (NAAQS). Air quality is

publicly significant because of the desire for clean air and public health concerns

expressed by many citizens.

The Clean Air Act Amendment of 1990 directed the USEPA to establish NAAQS for

all regulated air pollutants. Federal air quality standards have been established for

the following six pollutants that are considered as criteria air pollutants:

• Carbon monoxide (CO),

• Nitrogen dioxide (NO2

• Ozone (O

),

3

• Sulfur oxides (commonly measured as sulfur dioxide [SO

),

2

• Lead (Pb),

]),

• Particulate matter no greater than 2.5 micrometers (μm) in diameter

(PM2.5

• Particulate matter no greater than 10 μm in diameter (PM

), and

10).

These pollutants are known as criteria air pollutants.

Historic Conditions. The LCA ARDC study area was in nonattainment for

the interval 2004-2007 for ozone (8-hour average) (http://www.epa.gov/oar/data),

EPA 2009). The measurements include both criteria air pollutants and hazardous

air pollutants and are compared against the NAAQS specified by the USEPA. Each

row of the table lists standards-related air pollution values for available criteria

pollutants for one year. The values shown are the highest reported during the year

by all monitoring sites in each parish. Air quality is not a major issue for the LCA

ARDC study area.

Existing Conditions. Air quality in the LCA ARDC study area is generally

good to moderate, with minimal periods in which air quality is classified as

unhealthy for the general public or for sensitive groups

(http://www.epa.gov/oar/data, EPA, 2009). Of the six criteria air pollutants, O3 and

PM2.5 are most likely to occur within the Baton Rouge Metropolitan Statistical Area

(MSA). However, the air quality did not exceed NAAQS limits for these parameters

in the LCA ARDC study area for 2008 (http://www.epa.gov/oar/data). The area

is in a non-attainment area for ozone.

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4.2.5 Noise

Noise is institutionally significant because of the Noise Control Act of 1972 that

declares the policy of the United States is to promote an environment for all

Americans free from noise that jeopardizes their health or welfare; 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 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 (Kryter, 1994). Noise is

publicly significant because of the public's concern for the potential annoyance and

adverse effects of noise on wildlife and humans.

Occupational noise exposure is regulated by 29 CFR Part 1910, subpart G. The U.S.

Department of Labor, Occupational Safety and Health Administration (OSHA) is

the enforcing agency. OSHA has established noise exposure standards in order to

protect the hearing of employees. Noise exposure for the construction industry is

regulated by 29 CFR, Part 1926.52, and Occupational Noise Exposure.

Historic Conditions. Until development in the 1950s, noise pollution was of

no concern. More recent historical sources of noise have been developments (1980s)

and recreational boat traffic within the LCA ARDC study area.

Existing Conditions. Noise is typically associated with human activities

and habitations, such as the operation of commercial and recreational boats, ships,

air boats, and other recreational vehicles; operation of machinery and motors; and

human residential-related noise (air conditioners, lawn mowers, etc.). However, the

LCA ARDC study area is remote and uninhabited marsh. The noise from distant

urban areas has little if any impacts on the area. As the population in the LCA

ARDC study area continues to grow and develop, some noise pollution would occur.

The ambient noise caused by boat traffic and human activity in the ARDC, Amite

and Blind rivers may cause some minimal and temporary disturbances in 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 (CZM) of 1972;

Emergency Wetlands Resources Act of 1986; Estuary Protection Act of 1968; Fish

and Wildlife Conservation Act of 1980; the Fish and Wildlife Coordination Act of

1958, as amended; Migratory Bird Conservation Act; Migratory Bird Treaty Act;

Endangered Species Act of 1973 (ESA); the Magnuson-Stevens Fishery

Conservation and Management Act of 1976, as amended (Magnuson-Stevens Act);

the Magnuson-Stevens Reauthorization Act of 2006; NEPA; the North American

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Wetlands Conservation Act; the Water Resources Development Acts of 1976, 1986,

1990, and 1992; and EO 13186 Migratory Bird Habitat Protection. Coastal

vegetation resources are technically significant because they are a critical element

of the coastal habitats. Additionally, 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.

The LCA ARDC study area includes swamps, rivers, creeks, and bayous. Gulf

Coast estuaries are among the most productive natural systems, producing more

food per acre than the most productive Midwestern farmland and are second only to

Alaska for domestic landings of commercial fish and shellfish (National Coastal

Condition Report II) (http://www.epa.gov/owow/oceans/nccr/2005/index.html).

Habitat and historic land cover analysis for the LCA ARDC study area was

performed by the USGS (USGS 2009 Map ID; USGS-National Wetlands Research

Center [NWRC] 2010-11-007). The most recent land cover data identified by the

habitat analysis was the 2000 Louisiana Coastal Area Habitat dataset. This

dataset depicts information on the geographic distribution of land use/land cover for

Louisiana. This dataset consists of digital data describing the land use/land cover

(mainly vegetation, but including water and urban environments) for the State of

Louisiana. Information is presented in the form of digital maps compiled using

1999 LandSat 7 Thematic Mapper classified land/water data, 1993 land cover

classification for the Louisiana Gap Analysis Program, and 2001 Louisiana Coastal

Marsh Vegetative Type map data. Attribute fields describe the different land cover

types occurring within the polygon or associated with each pixel.

Approximately 27,984 acres are within the LCA ARDC study area. The geographic

distribution of these land cover classifications is shown in Figure 4.7. The various

land cover classifications, by acre, in the LCA ARDC study area, from the Louisiana

Coastal Area Habitat dataset are presented in Table 4.3. The vegetation

classification descriptions and acreage within the LCA ARDC study area are

described in the following sections.

Approximately 25,634 acres (91.6 percent) of the LCA ARDC study area is

comprised of wetland communities including forested and non-forested (scrub-shrub

wetlands and fresh marsh - Table 4.3). Forested upland communities comprise

approximately 441 acres (1.6 percent) of the LCA ARDC study area and consist

primarily of pine thickets or upland forest communities. Approximately 1,142 acres

(4.1 percent) of the LCA ARDC study area consist of open water, including rivers,

streams, and canals. Open water areas within the LCA ARDC study area include

the ARDC; the Amite, Petite Amite, and Blind Rivers; Bayous Pierre and Chene

Blanc; and the Chinquapin Canal; and are distributed throughout the LCA ARDC

study area. Developed land, which consists primarily of fringing suburbs and built239
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up areas of metropolitan communities containing sufficient coverage of woody and

non-woody vegetation to include urban features, comprises approximately 281 acres

(1.0 percent) of land within the LCA ARDC study area. Vegetated urban areas are

primarily confined to the dredged material berms lining the ARDC residential areas

adjacent to LA-22, and the right descending bank of the Amite River in the

northwestern portion of the LCA ARDC study area. Barren land makes up a small

percentage of the LCA ARDC study area and may include rangelands, strip mines,

quarries, and gravel pits. Agricultural cropland or grassland makes up

approximately 469 acres (1.6 percent) of the LCA ARDC study area and appears to

be restricted to livestock pasture. These pastures are located in isolated pockets

along the lower Amite River and LA-22 in the western LCA ARDC study area.

Table 4.3. Land Cover in the LCA ARDC Study Area by Acre

(2000 Louisiana Coastal Area Habitat Analysis)

Land Cover Classification Acres

Percent of

LCA ARDC

study area

Wetlands

Wetland Forest 25,316 90.4%

Non-Forested Wetland

Fresh marsh 226 0.8%

Wetland scrub/shrub 91 0.3%

Swamp 0 0.0%

Subtotal Wetlands 25,633 91.6%

Uplands

Upland forest 441 1.6%

Upland scrub/shrub 0 0.0%

Subtotal Uplands 441 1.6%

Water: Streams and Canals 1,142 4.1%

Developed Land 281 1.0%

Barren Land 18 0.1%

Agriculture/Pasture 469 1.6%

TOTAL 27,984 100%

Note: The 2000 Louisiana Coastal Area habitat data composition

is a hybrid dataset of the following:

• 1993 Land Cover Classification for the Louisiana Gap

Analysis Project;

• November 18, 1999 Landsat 7 TM Classified Land/Water

Data; and

• 2001 Louisiana Coastal Marsh Vegetation Type Map.

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4.2.6.1 Riparian Vegetation

Historic Conditions. Construction of the ARDC in 1956 created

riparian habitat along the sidecast dredged material berms; riparian habitat is also

present on some of the banks of other waterbodies (Figure 4.7). Riparian zones

within the LCA ARDC study area were historically confined to the natural banks of

the Petite Amite and Blind Rivers as well as a myriad of smaller natural tributaries

within the interior of the marsh.

Existing Conditions. Depending on the elevation, these corridors are

forested with a myriad of tree species; the wettest areas are dominated by bald

cypress/tupelo while the highest elevation areas are dominated by hardwood tree

species such as oak, ash and elm. Riparian habitat along the ARDC is well defined;

a steep geological gradient limits the influence of the ARDC and the spread of

hydrophytes. This area as well, has remained relatively stable since the ARDC was

completed.

4.2.6.2 Wetland Vegetation

Wetlands are defined as areas that are covered by water or that contain

saturated soils for a minimum of five percent of the growing season, or

approximately 14 days (33 CFR 328.3(b); 40 CFR 230.3(t)). Wetlands provide

protection from wave action, erosion, and storm damage and provide various

consumptive and non-consumptive recreational opportunities.

Historic Conditions. Prior to the early 20th century, the LCA ARDC

study area was an unbroken expanse of wetlands interspersed with meandering

bayous such as the Petite Amite and Amite Rivers. The LCA ARDC study area

contains approximately 27,984 acres of primarily bald cypress-tupelo swamp

habitat. The LCA ARDC study area is located within the Amite/Blind mapping unit

(LCWCRTF, 1999). This mapping unit contains 190,036 acres in portions of

St. James, Ascension, Livingston, and St. John the Baptist Parishes. Between 1932

and 1956, about 1,600 acres of wetlands were lost in the Amite/Blind mapping unit

mainly to shoreline erosion and direct removal (LCWCRTF, 1999). Although there

were no significant shifts in habitat type within this mapping unit from 1956 to

1990, the swamp vegetation is becoming increasingly stressed.

Existing Conditions. Wetland coverage data within the LCA ARDC

study area were obtained from the National Wetlands Inventory (NWI)

(www.fws.gov/wetlands). The NWI is maintained by the U.S. Fish and Wildlife

Service (USFWS) and provides general wetland occurrence data for coastal regions

in the United States. NWI data does not constitute geospatially precise wetland

delineations, but rather provide basic occurrence data regarding the classification

and approximate areal extent of wetland coverage within a given area. NWI

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wetland types are described according to the regimes devised in the USFWS

Publication Classification of Wetlands and Deepwater Habitats of the United States

(Cowardin et al., 1979).

Wetland habitat types within the LCA ARDC study area are

characterized into four major categories: palustrine forested (92.77 percent);

palustrine emergent, scrub-shrub, unconsolidated bottom, and aquatic bed

(1.2 percent); uplands (4.4 percent), and riverine (lacustrine). Figure 4.8 presents a

map of the wetland types in the LCA ARDC study area.

The most common wetland regime in the LCA ARDC study area is

wetland forest (Figure 4.7). About 18,204 acres of primarily bald cypress-tupelo

swamp habitat are presently impounded at different levels within the LCA ARDC

study area. Existing swamp habitats are converting to marsh and shallow open

water habitats. Saltwater intrusion from storm events has additionally stressed the

swamp habitat along the Blind River. The other dominant habitat types include

water (1,123 acres), upland forest (406 acres), agriculture/pasture (375 acres),

developed (251 acres), and fresh marsh (249 acres) (Figure 4.7).

Functions lost include habitat for wildlife and aquatic species,

recreational opportunities, aesthetics, and storm surge protection. Upon severe

degradation; the swamp will convert to freshwater marsh, then to open water. The

freshwater marsh does offer some of the functions of the freshwater swamp, but

certain functions are lost, such as habitat for avian species and storm surge

protection. It is a national priority to preserve and protect freshwater swamps.

Vegetation Communities. Common plant species in the LCA ARDC

study area are presented in Table 4.4 by habitat type. Many species occur in more

than one habitat. Highly flood-tolerant bald cypress (Taxodium distichum) and

water tupelo or tulepo-gum (Nyssa aquatica) dominate the overstory of much of the

Maurepas Swamp, including the LCA ARDC study area (Conner and Day, 1976).

This dominance is due in part to their ability to produce secondary roots with the

capacity to oxidize the area surrounding their roots in flooded, anaerobic soils.

In addition to bald cypress and water tupelo, swamp red maple (Acer

rubrum var. drummondii), green ash (Fraxinus pennsylvanica), swamp tupelo

(Nyssa sylvatica var. biflora), and various oak species (Quercus spp.) are also found

in bald cypress-tupelo swamp habitat within the LCA ARDC study area, with

swamp red maple and green ash comprising sub-dominant midstory species (Conner

and Day, 1976; Hoeppner, 2008; Shaffer et al., 2003). Scrub species, including black

willow (Salix nigra), wax myrtle (Morella cerifera), and buttonbush (Cephalanthus

occidentalis) are sporadically present, particularly in areas with diminished canopy

cover caused by impaired health or mortality of overstory species.

242
Figure 4.7. Land Cover within the LCA ARDC Study Area (USGS, 2009)

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244
Wetland Data: National Wetlands Research Center Habitat Data for Gulf of Mexico Coast, Louisiana, 1988

Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: November 2009Scale:Source: USDA/NWRC/GEC

WETLAND TYPE MAP

Map ID: 27850108-1850

LITTLE BAYOU CHENE BLANC

BAYOU C HENE

B

L

A NC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

NEW RIVER CANAL

PETITE AMITE RIVER

CHINQUAPIN CANAL

BAYOU AN

OT

NI E

FLAT

LAKE

PETITE A M TI E R VI

RE

BAYOU CHENE BLANC

OLD RIVE R

BAYOU PIERRE

BLAC K LAKE

HEATH BAYOU

1:90,000

0 0.5 1 1.5 2

Miles

Legend

Study Area

Wetland Code

L1UBHhPAB4HPEM1APEM1CPEM1ChPEM1FPFO1/2CPFO1/2CsPFO1/4APFO1APFO1As

PFO1CPFO1CsPFO1FPFO2/1CPFO2/1FPFO4/1APSS1/2FPSS1APSS1CPSS3CPUBHPUBHxR2UBH

R2UBHxUAUBUBsUF6UF7UF7sUF8URUSSUU

Figure: 4.8

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Table 4.4. Common Plant Species in the Study

Area by Habitat Type (USDA, 2008)

Common Name Scientific Name Habitat Type(s)

Bald cypress Taxodium distichum Bald cypress-Tupelo

Black Willow Salix nigra Bald cypress-Tupelo

Green Ash Fraxinus pennsylvanica Bald cypress-Tupelo

Swamp Tupelo Nyssa biflora Bald cypress-Tupelo

Tupelo Gum Nyssa aquatica Bald cypress-Tupelo

Buttonbush Cephalanthus

occidentalis

Bald cypress-Tupelo

Fresh Marsh

Bulltongue Sagittaria lancifolia Fresh Marsh

Intermediate Marsh

Dwarf Spikerush Eleocharis parvula Fresh Marsh

Intermediate Marsh

Wax Myrtle Myrica cerifera Fresh Marsh

Intermediate Marsh

Alligator Weed Alternanthera

philoxeroides Fresh Marsh

Arrow Arum Peltandra virginica Fresh Marsh

Lizard’s Tail Saururus cernuus Fresh Marsh

Maidencane Panicum hemitomon Fresh Marsh

Swamp Smartweed Polygonum punctatum Fresh Marsh

Chinese Privet Ligustrum sinense Upland Ridge

Chinese Tallowtree Triadica sebifera Upland Ridge

Swamp Red Maple Acer rubrum var.

drummondii

Upland Ridge

Bald cypress-Tupelo

Water Oak Quercus nigra Upland Ridge

Bald cypress-Tupelo

Laurel Oak Quercus laurifolia Upland Ridge

Bald cypress-Tupelo

Much of the bald cypress-tupelo swamp habitat within the LCA ARDC

study area is not fully stocked, suggesting that environmental stressors are

affecting regeneration and stand growth (Chambers et al., 2005). Altered

hydrological conditions in southeastern LA have reduced or eliminated natural

regeneration of bald cypress and water tupelo, and reduced productivity. Neither

bald cypress nor water tupelo seeds germinate in water, and submerged cypress

seedlings die within three to six weeks (Demaree, 1932, Souther, 2000). Flooding

caused by relative sea level rise (primarily as a result of regional subsidence) has

decreased the probability of natural regeneration of many stands of bald cypresstupelo forest (Conner et al., 1981; Chambers et al., 2005). The swamps in the LCA

ARDC study area and vicinity are impacted by elevated levels of subsidence and

consequent saltwater intrusion, and experience a lack of sediment and nutrient

input. Tree recruitment is further severely limited by the mammalian seedling

predator nutria (Myocastor coypus), and in many areas of the swamp, bald cypress

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and water tupelo are defoliated annually by outbreaks of bald cypress leafrollers

(Archips goyerana) and forest tent caterpillars (Malacosoma disstria) (Myers et al.,

1995; Beville, 2002; Effler, et al., 2006).

Vegetative communities are affected by water level and RSLR. The

RSLR that can be expected for the LCA ARDC Modification project area is from 5 to

9 mm/year (2 to 4 mm/year of subsidence and 3 to 5 mm/year of eustatic sea level

rise) (Penland and Ramsey 1990). Guidance provided from EC-1165-2-211 gives a

means by which to estimate the impacts of relative sea level rise. Specifically,

within the LCA ARDC study area, sea level rise is predicted to occur from 1.5 ft

(0.46 m) to 3.2 ft (0.97 m) over the 50-year period of analysis of the project.

Whether marsh substrate accretion can keep pace with sea level rise

depends on processes involving sediment deposition on the marsh surface and below

ground production of organic matter (DeLaune et al., 1983; Turner, 1990; Reed,

1995; Day et al., 2000). These processes vary both spatially and temporally and are

not well understood in many LA marsh systems (Jarvis C. Jessie, unpublished

data). It is estimated that the net accretion rate would be 8mm/year within the

healthiest portions of the LCA ARDC study area (Bernard Wood, unpublished data,

2005 through 2009). These net accretion rates account for subsidence, but not

eustatic sea level rise. Based on these estimates, accretion rates could reduce the

potential impacts of sea level rise within the healthiest portions of the LCA ARDC

study area.

4.2.6.3 Upland Vegetation

Several ridge remnants run through the LCA ARDC study area. These

ridges are mostly near the mid-point of the east-west stretch of the ARDC. The

dominant tree structure includes bald cypress, black gum, swamp gum,

Drummond’s red maple, green ash, diamond oak, water oak, black willow, American

elm, and tallow (Field Investigation, 2009). Wax myrtle, black berry, black willow,

Chinese tallow tree, and Chinese privet typically dominate the shrub stratum. In

addition, an old railroad grade and several earthen levees run through the LCA

ARDC study area with similar habitats.

Historic Conditions. Historically, the upland vegetation composition

has changed little from what can be found today. These uplands constituted old

natural levees that subsided at a different rate than the surrounding marsh.

Ultimately, as subsidence occurs over the course of thousands of years, these areas

are converted into freshwater swamps and then marshes before becoming open

water as they sink beneath mean water level. The vegetation of the ridges in the

coastal region served as refuges for wildlife and native people during high water

events and was important, both for food and forage.

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Settlers began to move into the area around 1721 (Haydel, 1998), but

no large scale alterations in the upland vegetation structure occurred until logging

operations for cypress began in 1891 and continued until the early 1930s (Haydel,

1998). A fully functional railroad carried logs that fell in the swamp to the sawmill;

the railroad was abandoned shortly after the mill closed. The great majority of the

forests were logged, leaving small, deformed target trees, and some non-target

species behind. The mature forest we see today is a regrowth.

The ARDC was completed in the 1964. The upland vegetation of the

dredged material berms lining the ARDC and the old railroad grade differs little

from the natural ridges in community composition.

Existing Conditions. Upland vegetation on the natural ridges is

being impacted due to increasing water in impounded areas. This stresses existing

trees and shifts the community toward a wetter cypress/tupelo forest. This

disturbance also provides an opportunity for invasive species to gain a foothold and

crowd out developing native vegetation. Upland vegetation on the dredged material

berms (spoil) and the railroad grade is undergoing a much more dramatic change as

threats from residential development impact the site.

4.2.6.4 Submerged Aquatic Vegetation

Submerged aquatic vegetation (SAV) is an important source of food and

habitat for both aquatic resources and wildlife. SAV provides structure and habitat

for many invertebrates that provide food for larger aquatic resources, such as many

stages of fishes. SAV also provides food for many avian species such as waterfowl.

SAV also provides feeding habitat for fish-eating birds such as herons and egrets.

Historic Conditions. SAV is limited to shallow areas with flow that

is high enough to keep the area clear of floating species within the ARDC and other

waterbodies. Historically, SAV communities within the LCA ARDC study area

have been dominated by native species such as fanwort (Cabomba carolinana),

coontail (Ceratophyllum demersum), small pondweed (Potamogeton pusillus),

bladderwort (Utricularia vulgaris), water nymph (Najas guadalupensis), widgeon

grass (Ruppia maritima), and wild celery (Vallisneria americana).

Existing Conditions. SAV communities within the LCA ARDC study

area are largely confined to areas of higher flow within the LCA ARDC study area.

This includes natural waterways and natural cuts into the swamp interior. Shallow

water habitats within the LCA ARDC study area that have insufficient flow have

become choked with floating vegetation, greatly limiting light penetration within

the water column.

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4.2.6.5 Invasive Species – Vegetation

The EO 13112 was signed on February 3, 1999 establishing the National

Invasive Species Council 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.

In coastal LA, water hyacinth (Eichhornia crassipes), alligatorweed

(Alternanthera philoxeroides), hydrilla (Hydrilla verticillata), and Chinese tallow

(Triadica sebifera) are well-known invasive plants. More recently, common salvinia

(Salvinia minima), giant salvinia (Salvinia molesta), and variable-leaf milfoil

(Myriophyllum heterophyllum) also have become invasive, displacing native aquatic

species and degrading water quality and habitat quality (LACPR, 2009). Invasive

plant species within the LCA ARDC study area include water hyacinth,

alligatorweed, hydrilla, common salvinia, giant salvinia, Chinese tallow, and

Chinese privet (Ligustrum sinense) (LCA, 2004).

Historic Conditions. Natural processes form coastal vegetation

resources. Invasive species have been intentionally and unintentionally released

and are outcompeting native vegetation species and spreading throughout many

habitat types. Historically (pre-European), the LCA ARDC study area consisted of

several palustrine habitats including submerged aquatic beds, fringe freshwater

marsh, and cypress/tupelo swamp. These systems were not impacted by any

invasive species.

Existing Conditions. Each of these invasive species is well

established within the LCA ARDC study area. The impacts of each of these species

on the native flora include physical competition for resources such as nutrients and

light, impacts to community structure and composition, and impact to ecosystem

processes and system wide parameters. Water hyacinth, common salvinia, giant

salvinia, and hydrilla all limit the amount of light penetrating the water column

which in turn impacts plankton biomass production. Alligatorweed, Chinese tallow

and Chinese privet are of minimal wildlife value and can proliferate until nearly

monocultural stands exist, limiting food available for wildlife.

4.2.6.6 Rare, Unique, and Imperiled Vegetative Communities

The unique communities, nestled within the broader vegetative habitats, are

important in that they contribute to the extensive diversity of the coastal

ecosystem, are the basis for its productivity, and are essential to the stability of the

bionetwork. Overall, plant communities provide protection against substrate

erosion and contribute food and physical structure for cover, nesting, and nursery

habitat for wildlife and fisheries. Continued degradation and loss of existing

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wetland areas would accelerate decline in the interdependent processes of plant

production and vertical accretion necessary for a stable ecosystem.

The Louisiana Natural Heritage Program (LNHP), administered by the

Louisiana Department of Wildlife and Fisheries (LDWF), maintains a directory of

over 6,000 occurrences of rare, threatened, or endangered species; unique natural

communities; and other distinctive elements of natural diversity; and has identified

approximately 380 ecologically significant sites statewide

(http://www.wlf.louisiana.gov/experience/naturalheritage/). The LNHP was

queried for site-specific rare, unique, or imperiled vegetative community occurrence

data in the LCA ARDC study area. According to this database, the only

communities present in the LCA ARDC study area are cypress-tupelo swamp and

fresh marsh.

4.2.7 Wildlife and Habitat

This resource is institutionally significant because of NEPA; the Coastal Zone

Management Act; Estuary Protection Act; the Fish and Wildlife Coordination Act of

1958, as amended; the Migratory Bird Conservation Act of 1929, as amended; the

Migratory Bird Treaty Act of 1918; the ESA of 1973, as amended; the Fish and

Wildlife Conservation Act of 1980; the North American Wetlands Conservation Act;

EO 13186 Migratory Bird Habitat Protection; Migratory Bird Conservation Act; and

the Marine Mammal Protection Act (MMPA). Wildlife resources are technically

significant because they are a critical element of the coastal barrier ecosystem, they

are an important indicator of the health of coastal habitats, and many wildlife

species are important recreational and commercial resources. Wildlife resources are

publicly significant because the public places a high priority on their aesthetic,

recreational, and commercial value.

The USFWS, in letters dated October 15, 2008 and January 20, 2009, formally

requested that significant fish and wildlife resources within the LCA ARDC study

area be fully considered and addressed in this study (Appendix B). The USFWS

identified two threatened and endangered species, Gulf sturgeon (Acipenser

oxyrhynchus desotoi) and West Indian manatee (Trichechus manatus), and one

delisted species, bald eagle (Haliaeetus leucocephalus) that are known to occur

within the LCA ARDC study area. Further information on Gulf Sturgeon and the

West Indian Manatee is available in Section 4.7.11 of the report. Additionally, the

USFWS indicated that the LCA ARDC study area is known to support colonial

nesting waterbirds (e.g., herons, egrets, ibis, night-herons, and roseate spoonbills).

As a result of the public review process, the USFWS recommended minimizing

disturbance to colonies containing nesting wading birds, 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, the USFWS recommended that on-site

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contract personnel be informed of the need to identify colonial nesting birds and

their nests, and should avoid affecting them during the breeding season.

Historic Conditions. The Amite/Blind River mapping unit contains part of

one of the largest remaining tracts of forested wetlands in the Lower Mississippi

River Valley and is extremely important to Neotropical migratory songbirds,

waterfowl and many other species of wildlife (LCWCRTF and WCRA, 1999).

Stopover habitat, where migratory birds can rest and refuel, is critical to successful

migrations, particularly across the Gulf of Mexico (Stouffer and Zoller, 2006).

Louisiana coastal wetlands provide Neotropical migrants essential stopover habitat

on their annual migration route. The greatest threat facing Neotropical migrants is

habitat loss (American Bird Conservancy, 2009). The coastal wetlands in the LCA

ARDC study area provide important wildlife habitats, especially transitional

habitat between estuarine and marine environments, used for shelter, nesting,

feeding, roosting, cover, nursery, and other life requirements. Table 4.5 shows the

status, functions of interest, trends, and projections through 2050 for avifauna,

furbearers, game mammals, and reptiles within the LCA ARDC study area and

vicinity (LCWCRTF and WCRA, 1999). See Section 4.2.11 for information about

threatened and endangered species.

The bald eagle was officially removed from the List of Endangered and

Threatened Species on August 8, 2007. However, the species continues to be

protected under the Migratory Bird Treaty Act (MBTA) and the Bald and Golden

Eagle Protection Act (BGEPA). The USFWS developed the National Bald Eagle

Management (NBEM) Guidelines to provide landowners, land managers, and others

with information and recommendations regarding how to minimize potential project

impacts to bald eagles, particularly where such impacts may constitute

“disturbance,” which is prohibited by the BGEPA. The guidelines recommend

maintaining: (1) a specified distance between the activity and the nest (buffer

area); (2) natural areas (preferably forested) between the activity and nest trees

(landscape buffers); and (3) avoiding certain activities during the breeding season.

The buffer areas serve to minimize visual and auditory impacts associated with

human activities near nest sites. Ideally, buffers would be large enough to protect

existing nest trees and provide for alternative or replacement nest trees. A copy of

the NBEM Guidelines is available at:

www.fws.gov/migratorybirds/issues/BaldEagle.

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Table 4.5. Status, Functions of Interest, Trends, and Projections through 2050 for

Avifauna, Furbearers, Game Mammals, and Reptiles within the

LCA ARDC Study Area (LCWCRTF and WCRA, 1999)

Mapping Unit Type % of unit

Furbearers Game Mammals Reptiles Avifauna

Nutria Muskrat Mink, Otter, and Raccoon Rabbit Deer Alligator Brown Pelican Seabirds Wading Birds

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

Amite/Blind

(Includes

LCA ARDC

study area)

FS 73 MuMo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo D D MuMo I D MuMo I I --- NH --- --- --- NH --- --- Ne Hi I I

HF 21 Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo Sy Sy Mu Lo D D MuMo I S Mu Lo Sy Sy --- NH --- --- --- NH --- --- --- NH --- ---

Mapping Unit Type % of unit

Avifauna (cont’d)

Shorebirds Dabbling Ducks Diving Ducks Raptors Rails, Coots Gallinules Other Woodland Residents Other Woodland Migrants

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

Amite/Blind

(Includes LCA

ARDC study

area)

FS 73 --- NH --- --- Mu Lo Sy Sy --- NH --- --- --- NH --- --- --- NH --- --- Ne Mo I Sy Mu Mo Sy Sy

HF 21 --- NH --- --- Mu Lo Sy Sy --- NH --- --- --- NH --- --- --- NH --- --- Ne Hi I D Mu Mu Sy D

Type: FS = Fresh Swamp; HF = Hardwood Forest.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

Trends (since 1985)/Projections (through 2050): Sy = Steady; D = Decrease; I = Increase; U = Unknown

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Existing Conditions. Louisiana’s coastal areas have many different

wildlife species, including important game animals such as white-tailed deer

(Odocoileus virginianus), eastern cottontail (Sylvilagus floridanus), swamp rabbit

(Sylvilagus aquaticus), gray squirrel (Sciurus canadensis), fox squirrel (S. niger),

and raccoon (Procyon lotor); furbearers include muskrat (Ondatra zibethicus),

nutria (Myocastor coypus), mink (Mustela vison), Virginia opossum (Didelphis

virginiana), striped skunk (Mephitis mephitis), bobcat (Lynx rufus), beaver (Castor

canadensis), and coyote (Canis latrans); insectivores, bats, rodents, and the ninebanded armadillo (Dasypus novemcinctus) (Gosselink et al., 1998.) The American

alligator (Alligator mississippiensis), wild turkey (Meleagris gallopavo), river otter

(Lutra canadensis), wading birds, dabbling ducks, and Neotropical songbirds are

also found. Hunting for deer, feral hogs, wild turkey, rabbits, squirrels, and ducks

occurs within and around the LCA ARDC study area.

Bald eagles nest in Louisiana from October through mid-May. Eagles

typically nest in mature trees (e.g., bald cypress, sycamore, willow) 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

Lake Salvador. 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 would typically defend against intrusion by other eagles, and that they likely

return to each year. A territory may include one or more alternative nests that are

built and maintained by the eagles, but which may not be used for nesting in a

given year. 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. Bald eagles are commonly seen in the LCA ARDC study area. A

bald eagle nest has been located within the LCA ARDC study area.

Invasive Wildlife Resources. Two invasive mammals, nutria and feral

hogs (Sus scrofa), can be found in the LCA ARDC study area (LDWF, 2010; Keddy,

et al., 2007).

Nutria are large semi-aquatic rodents introduced from South America that

live in fresh, intermediate and brackish marsh and feed on vegetation that is vital

to sustaining Louisiana’s coastline. High nutria population densities damage

wetland vegetation and further wetland loss. Nutria consume both above and below

ground parts of wetland plants (Keddy, et al., 2007). Nutria damage to areas,

referred to as “eat outs,” can be great. Nutria grazing can strip large patches of

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marsh, and their digging overturns the marsh’s upper peat layers (Keddy et al.,

2007). Aerial surveys estimated 80,000 acres of marsh were damaged by nutria;

nutria damage in recent years is concentrated in the Deltaic Plain in southeastern

Louisiana (Keddy et. al. 2007).

The feral hog is an exotic species which has expanded its range throughout

most of Louisiana. Feral hogs cause extensive damage to natural wildlife habitat,

privately-managed food plots for deer and turkey, and farm ponds and watering

holes for livestock. In Louisiana, the frequency of feral hogs around agricultural

areas has led to conflicts with sugarcane, rice, and corn farmers by the destruction

of crops from excessive digging (Reed, 2007). Additionally, the wild omnivores

compete with native wildlife for food resources; prey on young domestic animals and

wildlife; and carry diseases that can affect pets, livestock, wildlife and people

(Seward et al., 2004).

4.2.8 Aquatic Resources

Planktonic organisms are institutionally significant because of NEPA, the Coastal

Zone Management Act, and the Estuary Protection Act. This resource is technically

significant because plankton may provide a major, direct food source for animals in

the water column and in the sediments; plankton 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

food-energy for most estuarine systems; 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 in freshwater lakes and larger

rivers, plankton form the lowest trophic food level for many larger organisms

important to commercial and recreational fishing (Hynes, 1970).

Benthic organisms are institutionally significant because of NEPA; the Coastal

Zone Management Act; and the Estuary Protection Act. Benthic species are

technically significant because they are directly or indirectly involved in most

physical and chemical processes and trophic relationships that occur in aquatic

ecosystems. This resource is publicly significant because benthic organisms are

food for many larger organisms important to commercial and recreational fishing.

4.2.8.1 Plankton

Historic Conditions. Construction of the ARDC resulted in dredged

material berms which limits exchange of organisms and water between the swamp

and the ARDC. Phytoplankton (microscopic plants) are the primary producers of

the water column and form the base of the plankton community. Freshwater

zooplankton are dominated by four major groups of animals: protozoa, rotifers,

cladocerans, and copepods. Zooplankton provide the trophic link between the

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phytoplankton and the intermediate level consumers such as aquatic invertebrates,

larval fish, and smaller forage fish species (Day, et al., 1989). Zooplankton

populations in Louisiana ponds, swamps, ditches, and streams were found to be

primarily protozoa by Bamforth (1962). Rotifer populations peak once or twice a

year in coastal Louisiana freshwater systems, and during this peak may constitute

almost the entire zooplankton community (Gosselink et al., 1998).

Phytoplankton blooms can create anoxic conditions and can cause

widespread mortality of fish populations (Day et al., 2001). Phytoplankton

production in coastal wetland systems is most likely to be nitrogen limited (Day

et al., 2001). Swamps such as those present within the LCA ARDC study area have

been shown at times to be both sources and sinks of nutrients, particularly nitrogen.

Although phosphorus is typically the limiting nutrient which is attributed to

excessive algal growth (blooms), Lane et al. (2003) found that the Maurepas swamps

are nitrogen limited compared to phosphorus, and dissolved inorganic nitrogen,

especially nitrate, is the most important nutrient in the formation of phytoplankton

blooms in Lake Maurepas. Little phosphorus appears to be retained in swamp

vegetation, but instead is retained in the sediments. As long as sediment

mobilization remains low, phosphorus export should remain low (Mitsch and

Gosselink, 2000). Nitrogen is largely reduced by denitrification, but can also

undergo substantial reductions via burial in subsiding sediments (2003). Unsteady

State Hydraulic Models (UNET) (2003) predict that the Maurepas Swamp

ecosystem can remove up to 95 percent of nitrogen loads from surface waters via

several pathways, thus limiting potential algal blooms from freshwater diversions.

Existing Conditions. Plankton population changes may be

associated with the conversion of swamp habitat to freshwater marsh and open

water. Little information appears to be available on plankton communities in the

swamps along the ARDC. In general, running water almost always contains freefloating microorganisms, and in large rivers or sluggish streams, many of these

microorganisms are planktonic. However, these populations are unstable and

subject to constant change due to variable flows, turbidity, etc. (Hynes, 1970). Such

a variable plankton community, likely to be found in the ARDC, would be subject to

the flows of the Amite River and tidal influences through Lake Maurepas.

Within the swamp, the plankton community would be affected by

existing conditions, including the lack of hydrological connectivity with the ARDC.

A lack of nutrients, combined with shading due to a forest canopy and/or the

presence of floating plants (e.g., water hyacinth, salvinia, duckweed), could depress

photosynthesis and, therefore, phytoplankton populations. Zooplankton

populations could, in turn, be depressed.

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4.2.8.2 Benthic

Historic Conditions. Construction of the ARDC resulted in dredged

material berms which limits exchange of benthic organisms and water between the

swamp and the ARDC. 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. Major

consumer groups of the benthic habitat include bacteria and fungi, microalgae,

meiofauna, and microfauna (Mitsch and Gosselink, 2000). One of the main

functions of a benthic community is secondary production, the conversion of plant

material (formed in primary production) by benthic detritivores and herbivores to

animal tissue, thereby forming major links in the aquatic food web between plants

and predators (Cole, 1975).

Existing Conditions. Benthic population changes are associated

with the conversion of swamp habitat to freshwater marsh and open water. Within

the LCA ARDC study area, the benthic community is seasonally abundant, typically

during winter months when cooler water temperatures facilitate higher DO

concentrations. Organisms found in winter include a wide variety of segmented and

flatworms, snails, crustaceans, and insects. During summer, when little DO is

present, the benthic community is sparse, and air-breathing insects and

crustaceans; a few tubificid oligochaetes and dipterans, which can tolerate lower

oxygen conditions; and crawfish, especially burrowing crawfish, may be found.

During periods when the swamp floor dries, these organisms survive through the

production of resistance stages (eggs, cocoons, etc.) and repopulate the area when

flooding of the swamp floor returns (Loden, 1978).

4.2.9 Fishery Resources

Fishery resources are institutionally significant because of the Fish and Wildlife

Coordination Act of 1958, as amended; the Endangered Species Act(ESA) of 1973;

the Magnuson-Stevens Fishery Conservation and Management Act of 1976, as

amended (Magnuson-Stevens Act); the Magnuson-Stevens Reauthorization Act of

2006; the Coastal Zone Management Act; and the Estuary Protection Act. Fishery

resources are 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.

National Marine Fisheries Service (NMFS), in a letter dated February 20, 2009,

indicated that aquatic and wetland habitats in the LCA ARDC study area provide

foraging and nursery habitat for a few economically important marine fishery

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species that use freshwater habitats in this area. The species expected to be found

in the LCA ARDC study area include striped mullet (Mugil cephalus) and Gulf

menhaden (Brevoortia patronus). Although the area likely provides some habitat

for a few euryhaline species, it is not classified as Essential Fish Habitat (EFH)

(EFH - Rick Hartman, NMFS, pers. comm.). In addition, the waterbodies and

wetlands of the LCA ARDC study area provide nursery and foraging habitats

supportive of a variety of fishery species, some of which may serve as prey for other

fish species.

Emergent wetlands and shallow open water areas in the LCA ARDC study area

provide important and essential fishery habitats including transitional habitat

between freshwater and estuarine environments used by migratory and resident

fish and other aquatic organisms for nursery, foraging, breeding and spawning, and

other life requirements. The area historically and currently provides habitat for

recreational fishing; some commercial catfishing and crabbing occurs in the Blind

River and the Amite River near the LCA ARDC study area. Population trends for

fishery species within the LCA ARDC study area are presented in Table 4.6

(LCWCRTF and WCRA 1999). The Amite/Blind River mapping unit has shown

steady populations over the last 10 to 20 years for blue crab (Callinectes sapidus),

largemouth bass (Micropterus salmoides), and channel catfish (Ictalurus punctatus).

In the LCA ARDC study area, populations are expected to remain steady through

2050. Globally, overfishing and habitat change have resulted in the depletion of 90

percent of the world’s seafood resources (Worm et al., 2006). Of the species studied,

38 percent have experienced more than 90 percent depletion. Seven percent of the

species studied have become extinct (Worm et al., 2006).

Historic Conditions. Construction of the ARDC and dredged material

berms has prevented exchange of organisms and water between the swamp and the

ARDC. The fish species assemblage in the vicinity of the ARDC is primarily

composed of freshwater species, with occasional transient marine and diadromous

species. Laiche (1980) sampled fish at 73 different locations along the Amite River

using seines. Trammel net and additional seine samples were taken in the lower

portion of the river. Forty-nine species were collected in 11 collections from the

middle mainstream of the river (north of the LCA ARDC study area) and 41 species

were collected in 10 seine collections from the lower mainstream (near the

confluence of the ARDC and the Amite River). Most of the species collected were

freshwater species; however, a few transient marine species were observed or

collected. The most abundant species collected were blacktail shiner (Cyprinella

venusta), bullhead minnow (Pimephales vigilax), mosquitofish (Gambusia affinis),

longear sunfish (Lepomis megalotis), mimic shiner (Notropis volucellus), blackstripe

topminnow (Fundulus notatus), bluegill (L. macrochirus), and longnose shiner (N.

longirostris).

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Table 4.6. Population Trends and Projections through 2050

For Fishery Species within the Amite/Blind River

Mapping Unit (LCWCRTF and WCRA, 1999)

Fishery Species

Amite/Blind Mapping Unit

(Includes LCA ARDC study area)

Trend Projection

Red drum Not Applicable Not Applicable

Black drum Not Applicable Not Applicable

Spotted sea trout Not Applicable Not Applicable

Gulf menhaden Unknown Unknown

Southern flounder Not Applicable Not Applicable

American oyster Not Applicable Not Applicable

White shrimp Not Applicable Not Applicable

Brown shrimp Not Applicable Not Applicable

Blue crab Steady Steady

Spanish mackerel Not Applicable Not Applicable

Largemouth bass Steady Steady

Channel catfish Steady Steady

A total of 21 species were collected in the Amite River by Lantz (1970) using

rotenone and seine. Primarily freshwater species were collected, although a few

transient marine species were also collected or reported. The species with the

highest standing crop collected by rotenone were blue catfish (Ictalurus furcatus),

gizzard shad (Dorosoma cepedianum), spotted gar (Lepisosteus oculatus), freshwater

drum (Aplodinotus grunniens), channel catfish (I. punctatus), striped mullet, and

largemouth bass. Young-of-the-year fish collected by seining (in order of decreasing

abundance) included bluegill, black crappie (Pomoxis nigromaculatus), longear

sunfish (L. megalotis), spotted bass (M. punctulatus), and largemouth bass.

Watson et al. (1981) used rotenone and gill nets to collect 57 species of fish in

the Blind River, including 43 freshwater species, 12 estuarine species, and two

diadromous species. The authors suggested the confluence of the ARDC was a point

of separation between the upper and lower reaches of Blind River. The lower Blind

River had the greatest species diversity, primarily due to the presence of estuarine

species. The low concentrations of DO above the ARDC could be an important

limiting factor in the distribution of fish.

Hastings et al. (1987) utilized trawls, gill nets, and rotenone to collect 67

species of fish in Lake Maurepas. Two of the sampling stations were located at the

mouths of the Amite and Blind Rivers. The distributions of species were: 55 percent

freshwater, 40 percent marine, and 4 percent diadromous. The salinity in Lake

Maurepas was variable; during periods of higher salinities, marine species

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comprised a larger component of the lake’s species assemblage (Hastings et al.,

1987). When the salinity in the lake is higher, marine species are also more likely

to be present in the Amite and Blind Rivers.

Existing Conditions. Fishery population changes are associated with the

conversion of swamp habitat to freshwater marsh and open water habitat and as

water quality declines. Coastal wetlands and open waters in the LCA ARDC study

area provide important habitat for aquatic species. The area historically and

currently provides valuable habitat for recreational fishing and nursery areas for a

variety of finfish (Laiche, 1980; Watson et al., 1981; Hastings et al., 1987).

4.2.10 Essential Fish Habitat (EFH)

EFH is institutionally significant because of the Magnuson-Stevens Fishery

Conservation and Management Act of 1996. EFH is technically significant because

EFH includes “those waters and substrate necessary to fish for spawning, breeding,

feeding or growth to maturity.” The high value that the public places on seafood,

recreational and commercial opportunities makes EFH a publicly significant

resource. Specific categories of EFH include all estuarine waters and substrates

(mud, sand, shell, rock, and associated biological communities), including the subtidal vegetation (sea grasses and algae) and adjacent inter-tidal vegetation

(marshes and mangroves).

The LCA ARDC study area does not contain any areas classified as EFH, although

the area likely provides some habitat for a few euryhaline species (Rick Hartman,

NMFS, pers. comm., March 27, 2009).

Historic Conditions. The LCA ARDC study area has never contained any

areas classified as EFH. Although the area likely provides some habitat for a few

euryhaline species, it is not classified as EFH (Rick Hartman, NMFS, personal

communication, April 2009).

Existing Conditions. The LCA ARDC study area does not contain any

areas classified as EFH. Although the area likely provides some habitat for a few

euryhaline species, it is not classified as EFH (Rick Hartman, NMFS, personal

communication, April 2009).

4.2.11 Threatened and Endangered Species

This resource is institutionally significant because of the ESA of 1973, as amended,

and the MMPA. Endangered and threatened 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.

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The ESA of 1973 (16 USC 1531-1543) specifies that all Federal agencies are

required to undertake programs for the conservation of threatened and endangered

species and are prohibited from authorizing, funding, or undertaking any action

that jeopardizes a species protected under the ESA or modifies its designated

critical habitat. The provisions of the ESA apply only to species listed in the

Federal Register as threatened or endangered.

Historic Conditions. There has been a decrease in some animal and plant

populations and their critical habitat including loss of wetlands.

Federally-Listed Endangered and Threatened Species. Within the

State of Louisiana, 29 animal and three plant species (some with critical habitats)

are under the jurisdiction of the USFWS and NMFS that are presently classified as

threatened or endangered (Table 4.7). The USFWS and NMFS share jurisdictional

responsibility for sea turtles and the Gulf sturgeon. The USFWS, in a letter dated

January 20, 2009, identified two threatened and endangered species (Gulf sturgeon

and West Indian manatee) and one delisted species (bald eagle) that are known to

occur within the LCA ARDC study area.

West Indian Manatee – The West Indian manatee is listed as endangered

in Ascension Parish. The West Indian manatee occurs in shallow, slow-moving

rivers, estuaries, saltwater bays, canals and coastal areas. Manatees occasionally

enter Lakes Pontchartrain and Maurepas and associated coastal waters and

streams during the summer months, i.e., June through September. Manatee

occurrences appear to be increasing in coastal Louisiana, and sightings have been

reported in the Amite, Blind, Tchefuncte, and Tickfaw rivers, and in canals within

the adjacent coastal wetlands. The manatee has declined in numbers as a result of

collisions with boats, entrapment in flood control structures, poaching, habitat loss,

and pollution. Cold weather and outbreaks of red tide may also adversely affect the

species.

Gulf Sturgeon - The Gulf sturgeon is listed as threatened in Ascension and

Livingston Parishes. The Gulf sturgeon is anadromous and occurs in many rivers,

streams, and estuarine waters along the northern Gulf coast between the

Mississippi River and the Suwannee River in Florida. In Louisiana, Gulf sturgeon

has been reported at Rigolets Pass, rivers and lakes of the Lake Pontchartrain

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. Sturgeon, 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

overfishing have negatively affected the species.

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Table 4.7. Endangered (E) and Threatened (T) Plant

and Animal Species in Louisiana

Species Under Jurisdiction of the USFWS

Status Common Name

(Scientific Name)

Species Under Jurisdiction of NMFS

Status Common Name

(Scientific Name)

E

Mammals

1

E

-- Florida panther (Felis concolor coryl) 1

E -- West Indian manatee (Trichechus manatus)

-- Red wolf (Canis rufus)

T -- Louisiana black bear (Ursus americanus luteolus)

E

Birds

2

E

-- Bachmans's warbler (Vermivora bachmanii) 1

E

-- Eskimo curlew (Numenius borealis) 1

E -- Least tern; interior population (Sterna

antillarum)

-- Ivory-billed woodpecker (Campephilus

principalis)

E -- Red-cockaded woodpecker (Picoides borealis)

T -- Piping plover (Charadrius melodus)

E

Reptiles

3

E

-- Hawksbill sea turtle (Eretomchelys imbricata) 3

E

-- Kemp's (Atlantic) Ridley sea turtle (Lepidochelys

kempii) 3

T(S/A)

-- Leatherback sea turtle (Dermochelys coriacea) 4

T -- Gopher tortoise (Gopherus polyphemus)

--American alligator (Alligator

mississippiensis)

T3

T

-- Green sea turtle (Chelonia mydas) 3

T -- Ringed sawback turtle (Graptemys oculifera)

-- Loggerhead sea turtle (Caretta caretta)

E -- Pallid sturgeon (Scaphirhynchus albus)

Fish

T3 -- Gulf sturgeon (Acipenser oxyrinchus

desotoi)

E -- Mussel, Fat pocketbook (Potamilus capax)

Invertebrates

E -- Pink pearlymussel Mucket (Lampsilis abrupta)

T -- Inflated (Alabama) heelsplitter (Potamilus

inflatus)

T -- Louisiana pearlshell (Margaritifera hembeli)

E -- American chaffseed (Schwalbea americana)

Plants

E -- Louisiana quillwort (Isoetes louisianensis)

T -- Earth fruit (Geocarpon minimum)

Candidate Species

C -- Snake, Louisiana pine (Pituophis ruthveni)

5

E -- Sperm whale (Physeter macrocephalus)

Marine Mammals

E -- Sei whale (Balaenoptera borealis)

E -- Humpback whale (Megaptera novaeangliae)

E -- Finback whale (Balaenoptera physalus)

E -- Blue whale (Balaenoptera musculus)

Sea Turtles

E -- Hawksbill sea turtle (Eretomchelys imbricata)

3

E -- Kemp's (Atlantic) Ridley sea turtle (Lepidochelys

kempii)

E -- Leatherback sea turtle (Dermochelyscoriacea)

T -- Green sea turtle (Chelonia mydas)

T -- Loggerhead sea turtle (Caretta caretta)

T -- Gulf sturgeon (Acipenser oxyhyinchus desotoi)

Fish

Candidate Species

Dusky shark (Carcharhinus obscurus)

5

Sand tiger shark (Odontaspis taurus)

Night shark (Carcharinus signatus)

Speckled hind (Epinephelus drummondhayi)

Saltmarsh topminnow (Fundulus jenkensi)

Jewfish (Epinephelus itajara)

Warsaw grouper (Epinephelus striatus)

___________________________________________

1 Florida panther, red wolf, Eskimo curlew, and ivorybilled woodpecker presumed extirpated in the state. 2 No confirmed sightings of Bachman’s warbler on U.S.

nesting grounds since mid-1960s. Species may be

extirpated in Louisiana. 3 USFWS and NMFS share jurisdictional

responsibility for sea turtles and the Gulf sturgeon. 4 Alligator in Louisiana is classified for law

enforcement purposes as "Threatened due to

Similarity of Appearance." They are biologically

neither endangered nor threatened. Regulated

harvest is permitted under state law. 5

Legend: E=Endangered; T= Threatened; C=Candidate

Candidate species are not protected under the ESA,

but concerns regarding their status indicate they may

warrant listing in the future. Federal agencies and

the public are encouraged to consider these species

during project planning so that future listings may be

avoided.

Species in bold type are those potentially found within the LCA ARDC study area

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On March 19, 2003, the USFWS and NMFS 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. Within Louisiana, this

critical habitat includes portions of the Pearl and Bogue Chitto rivers, Lake

Pontchartrain east of the Greater New Orleans Expressway Commission Causeway,

Little Lake, the Rigolets, Lake St. Catherine, and Lake Borgne. Gulf sturgeon have

been observed in waterbodies within the LCA ARDC study area; however, these

waterbodies are not within the critical habitat.

Louisiana State Rare, Threatened, and Endangered Species and

Natural Communities. The LNHP, founded in 1984 through a partnership with

the State of Louisiana and The Nature Conservancy, is maintained by the LDWF.

The LNHP 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. According to the database, 21 species and natural

communities (Table 4.8) occur in Ascension and Livingston Parishes. The USFWS,

in a letter dated October 15, 2008, also noted that the proposed LCA ARDC study

area is known to support colonial nesting waterbirds.

Table 4.8. Rare, Threatened, and Endangered Species and

Natural Communities Tracked by the LNHP,

Ascension and Livingston Parishes-January 2010

Scientific Name Common Name State Rank1

Acipenser oxyrinchus desotoi Gulf sturgeon S1S2/Threatened

Aimophila aestivalis Bachman’s sparrow S3

Alosa alabamae Alabama shad S1

Bottomland hardwood forest Bottomland hardwood forest S4

Cypress-tupelo swamp Cypress-tupelo swamp S4

Haliaeetus leucocephalus Bald eagle S2N,S3B/Endangered

Hemidactylium scutatum Four-toed salamander S1

Lampsilis ornata Southern pocketbook S3

Mustela frenata Long-tailed weasel S2S4

Ophisaurus ventralis Eastern glass lizard S3

Picoides borealis Red-cockaded woodpecker S2

Potamilus inflatus Inflated heelsplitter S1/Threatened

Rhadinaea flavilata Pine woods snake S1

Rhynchospora miliacea Millet beakrush S2

Sorex longirostris Southeastern shrew S2S3

Spilogale putorius Eastern spotted skunk S1

Spruce pine-hardwood mesic flatwoods Spruce pine-hardwood mesic flatwoods S2

Stewartia malacodendron Silky camellia S2S3

Trichechus manatus West Indian manatee SZN/Endangered

Trichomanes petersii Dwarf filmy-fern S2

Waterbird nesting colony Waterbird nesting colony SNR

1

Source: http://www.wlf.louisiana.gov/experience/naturalheritage/rarespeciesandparishhabitats/)

State Element Ranks: S1 = critically imperiled in Louisiana because of extreme rarity; S2 = imperiled in

Louisiana because of rarity; SZ = transient species in which no specific consistent area of occurrence is

identifiable; B = breeding occurrence; N = nonbreeding occurrence; S? = rank uncertain.

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Existing Conditions

Federal Designation. Two animals under the Federal jurisdiction of

the USFWS and/or the NMFS, presently classified as endangered or threatened are

within the LCA ARDC study area (Table 4.9).

Table 4.9. Threatened and Endangered Plant and Animal

Species in the LCA ARDC Study Area (LNHP, 2008)

Species Critical

Habitat

Status Jurisdiction

Federal State USFWS NMFS

LISTED SPECIES

Red-cockaded woodpecker (Picoides borealis) E E X

West Indian manatee (Trichechus

manatus) E E X

Gulf sturgeon (Acipenser oxyrhynchus

desotoi) T TX X

Alabama shad (Alosa alabamae) C S1 X

Inflated heelsplitter (Potamilus inflatus) T T X

RARE SPECIES

Bachman’s sparrow (Aimophila aestivalis) S3

Dwarf filmy fern (Trichomanes petersii) S2

Eastern glass lizard (Ophisaurus ventralis) S3

Eastern spotted skunk (Spilogale putorius) S1

Four-toed salamander (Hemidactylium

scutatum) S1

Long-tailed weasel (Mustela frenata) S2S4

Millet beakrush (Rhynchospora miliacea) S2

Pine woods snake (Rhadinaea flavilata) S1

Silky camellia (Stewartia malacodendron) S2S3

Southeastern shrew (Sorex longirostris) S2S3

Southern pocketbook (Lampsilis ornata) S3

Notes: Species with occurrences within LCA ARDC study area as documented by USFWS and/or LNHP are

denoted by a bold font.

Status: E-Endangered

T-Threatened

C-Candidate

D-Delisted

S1-Critically imperiled in LA

S2-Imperiled in LA

S3-Rare and local throughout LA

S4-Apparently secure in LA

SR-Reported in LA

State Designation. The LNHP maintains a database of rare,

threatened, and endangered species of plants, animals, and natural communities for

Louisiana. The LNHP lists 11 rare species within Ascension and Livingston

Parishes that may potentially be present within the LCA ARDC study area

(Table 4.8). Additionally, the LNHP lists the following species or rare elements as

occurring in the LCA ARDC study area:

• Bald cypress-tupelo swamp habitat,

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• A bald eagle nest; and

• Two great blue heron rookeries.

4.2.12 Cultural and Historic Resources

This resource is institutionally significant because of NEPA and the National

Historic Preservation Act of 1966 (NHPA). This resource is technically significant

due to the importance of protection and conservation of traditional cultural

resources, historic buildings and structures, and other valued cultural resources.

This resource is publicly significant because the public demands the preservation of

cultural resources.

Section 106 of the NHPA requires Federal agencies to take into account the effects

of their undertakings on historic properties, and afford the Advisory Council on

Historic Preservation (ACHP) a reasonable opportunity to comment. The historic

preservation review process mandated by Section 106 is outlined in regulations

issued by ACHP. Revised regulations, "Protection of Historic Properties" (36 CFR

Part 800), became effective January 11, 2001.

The State Historic Preservation Office (SHPO) administers the national historic

preservation program at the state level, reviews National Register of Historic Places

nominations, maintains data on historic properties that have been identified but not

yet nominated, and consults with Federal agencies during Section 106 review. The

two historic properties located within the LCA ARDC study area are the ARDC

(Division of Archeology site number 16LV103/16AN84) and the abandoned railroad

grade (Division of Archeology site number 16LV102).

The ARDC is a 10.6 mi. long artificial channel that extends from the Amite River at

Mile 25.3 to Mile 4.8 of the Blind River in Ascension and Livingston Parishes (see

Figure 1.2). The ARDC is recommended not eligible for National Register of

Historic Places (NRHP) nomination. While a number of historic canals are NRHP

listed—the Chesapeake and Ohio Canal, the Delaware Canal, and the Ohio and

Erie Canal for example—the significant examples are typically pre-20th century

transportation features that contributed significantly to their region’s historic

economy and, in some cases, also represent significant engineering innovations or

feats. In contrast, the ARDC is one of a number of similarly constructed post WW II

canals that were simply designed to improve flood control and drainage. Other

examples in the immediate vicinity include the Chinquapin Canal and the New

River Canal.

The abandoned railroad grade is an 8 km long linear feature within the LCA ARDC

study area (see Figure 1.2). It extends south from the Chinquapin Canal, across

Chene Blanc Bayou and the ARDC, and then turns east as it approaches the Blind

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River. Additionally, it extends north and south of the LCA ARDC study area in the

adjoining swamps that are beyond the LCA ARDC study area.

The old railroad grade is recommended not eligible for NRHP nomination.

Abandoned railroad grades that are associated with the historic lumber industry

are ubiquitous in Louisiana. The old grade represents only a portion of the former

railroad infrastructure, and it has been modified by the removal of the wooden ties

and steel rails.

Historical Conditions. Cultural resources have been subject to natural

and man-made processes. Recorded archival and historical research was conducted

to develop a baseline level of knowledge for prehistoric and historic period cultural

developments and to identify archeological and historical sites previously recorded

in the LCA ARDC study area. Among the research efforts, a review of historical

literature and previous archeological investigation reports yielded information

useful for developing a general chronology of cultural developments across the

region.

Existing Conditions. Human activities, as well as natural processes, can

potentially destroy historic and natural resources. The loss of land threatens the

existence and integrity of these resources. An inventory of identified cultural

resource sites within the LCA ARDC study area was compiled through database

and paper map searches located at the SHPO. The SHPO manages these resources

through the Divisions of Archaeology and Historic Preservation for use during the

Section 106 Review process. The Division of Archaeology houses records of

archaeological resources both on USGS 7.5-minute series quadrangle maps and a

confidential cultural resources geodatabase layer. Cultural affiliation, National

Register status, and other descriptive details of the archaeological sites are recorded

on site forms stored at the Division. Information concerning areas previously

surveyed for cultural resources depicted on parish-wide street maps and the

corresponding reports can also be obtained from the Division of Archaeology.

Standing structure forms are managed by the Division of Historic Preservation and

are housed at the Louisiana State Library. These forms record data providing

National Register status, structural details, historical significance, and photographs

of the surveyed structure. Locations and ownership information for these standing

structures are also maintained in a public cultural resources geodatabase layer.

Preliminary archival research of recorded cultural resources in the

geodatabase layers and USGS quadrangle maps identified five archaeological sites

within or immediately adjacent to the LCA ARDC study area, including a mound

site on the Bayou Chene Blanc bankside, shell middens on Bayou Chene Blanc (two

sites) and ARDC (one site north of the LCA ARDC study area) banksides, and a

shell midden and prehistoric scatter on the lower Amite River bankside

(Table 4.10). The mound site on Bayou Chene Blanc could not be located and is

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presumed to be destroyed. While these sites are located within the vicinity of the

LCA ARDC study area, no impact to these identified sites is anticipated from

project activities. No standing structures were identified within or immediately

adjacent to the LCA ARDC study area during preliminary archival research. No

archaeological sites were located at the five proposed cuts.

Table 4.10. Identified Archaeological Sites Within

the LCA ARDC Study Area (SHPO, 2008)

Site ID

No. Description Location Comments NRHPStatus

16LV91 Destroyed

mound site

Bayou Chene

Blanc bankside

Possible camp

site Eligible

16LV92 Shell midden Bayou Chene

Blanc bankside

Possible camp

site

Potentially

eligible

16LV93 Shell midden Bayou Chene

Blanc bankside

Possible camp

site

Potentially

eligible

16LV5

Shell midden

and prehistoric

scatter

Amite River

bankside

Possible

prehistoric

hamlet or

village

Eligible

16AN16 Shell midden ARDC bankside

Possible

prehistoric

hamlet or

village

Unknown

On October 19, 2009, Panamerican Consultants Inc. performed a cultural

resources survey of the five proposed cuts in the ARDC. No archeological sites were

located at five proposed cuts, but one modern Rangia scatter was observed near

cut 5. The Rangia scatter was considered an insignificant finding. The two historic

properties located within the LCA ARDC study area are the ARDC (Division of

Archeology site number 16LV103/16AN84) and the abandoned railroad grade

(Division of Archeology site number 16LV102). Both of these sites are ineligible for

the National Register of Historic Places.

A letter of SHPO concurrence with these findings was received January 2010

(Appendix F). This letter states that the office concurs with the findings. It does

not appear that any significant archeological sites or historic properties will be

affected by the proposed project. Therefore, cultural resources need not be further

considered during pursuit of the project for which the investigations were

conducted.

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

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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) (Appendix F). The

Programmatic Agreement establishes the procedures for consultation, identification

of historic properties, assessment and resolution of adverse effects.

4.2.13 Aesthetics

This resource is institutionally significant because of the Natural and Scenic River

Systems and the National Wild and Scenic Rivers System created by Congress in

1968 (Public Law 90-542; 16 U.S.C. 1271 et seq.) Aesthetics is technically

significant because the visual complexity provides an indication of the overall

health of an ecosystem. Aesthetics are publicly significant because of the desire of

the public to protect habitats and viewscapes.

Historic Conditions. The streams of the project area were essentially what

they are today, and there were no canals. The streams were not seen by many

people because the area was remote and opportunities for fishing and boating were

widespread for people in the major population centers such as Baton Rouge and

New Orleans. The project area was a virgin forest before it was clear cut in the

early 1900s. However, the interior swamps would have been seen only by a few

trappers. The logging operations decimated the swamps, which subsequently were

recovering from an aesthetic perspective until the construction of the ARDC

introduced new conditions of decline and cut across some of the existing streams

such as the Petite Amite River. However, one of the major effects of the ARDC was

to open the project area to a high level of visitation and enjoyment.

Louisiana Scenic Rivers and Streams. The Louisiana Natural and

Scenic River System is one of the Nation’s largest, oldest, most diverse and unique

state river protection initiatives (Louisiana State University [LSU] Agricultural

Center, 2009). It encompasses over 80 streams or stream segments including over

3,000 linear miles (4,827 km) of Louisiana’s streams, rivers, and bayous (LDWF,

2005). The streams in the system vary from fast flowing upland streams with riffles

and waterfalls to sluggish swamp bayous flanked by Spanish moss draped cypress

trees to brackish water tidal creeks in the coastal marshes. A natural or scenic river

is a river, stream, or bayou that is in a free-flowing condition and has not been

altered by channelization or realignment (Louisiana Scenic Rivers Act [LSRA] -

Acts 1988, No. 947, § 1, eff. July 27, 1988). A stream can also be classified as scenic

if it has been altered, but contains native vegetation and has little or no manmade

structures along its bank. The LDWF administers the Louisiana Natural and

Scenic Rivers system established in 1970 for the purpose of preserving, developing,

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reclaiming and enhancing the wilderness qualities, scenic beauties and ecological

regime of designated free-flowing waterbodies. The LCA ARDC study area is made

up mostly of open water marshes, swamps and bayous. Blind River is a designated

scenic river located adjacent to the LCA ARDC study area.

Existing Conditions

Streams and Canals - The primary streams in the project area are

the Petite Amite River, Blind River, Little Bayou Chene Blanc, and Bayou Chene

Blanc. All of these streams are placid, run through swamps, have low banks that

allow views into the immediate interior, and are occasionally fringed by large

cypress trees that were too decayed or deformed to harvest. The water is generally

clean and free of debris and obstructions, with the exception of rapidly spreading

Salvinia sp. that stretches across portions of the Petite Amite River and the Blind

River and forms a solid mass on the Blind River before its confluence with the

Petite Amite River. The Blind River is a designated Wild and Scenic River, a status

suggestive of its aesthetic qualities.

The two canals in the project area are the Chinquapin Canal and the

ARDC. The Chinquapin Canal runs through swamp and is straight and narrow,

with dredged materials placed on the north bank and the south open to views of the

swamp. It is generally clean and free of debris until nearing Berthelot’s

Campground.

The primary feature of the ARDC from an aesthetic perspective is its

large bank-to-bank size and a length that establishes a sense of vista, whether

viewed from a boat, a bridge, or a residence. Housing on the north side of the canal

in Riverfront East is elegant, with manicured yards. Campsites on the south side in

Three Rivers Island are architecturally varied and rise to greater heights than the

homes on the north side, providing visual contrast. Residents enjoy sitting in their

back yards simply to view the water.

Swamps and Ridges - Apart from Berthelot’s Campground, the small

strip of housing and campsite development on the ARDC, and the old railroad

grade, most of the project area is composed of swamps and ridges. The ridges are

small rises in the swamp and are occupied by water oak, diamond oak, sweetgum,

ash, wax myrtle, black willow, Chinese tallow, and privet. They provide an idyllic

setting in contrast to the surrounding darkness and wetness of the swamps and a

welcome relief for hunters, nature observers, bird watchers, and ecologists.

From an aesthetic perspective, the swamps of the project area can be

characterized as either healthy or degraded. The healthy areas have a fairly dense

canopy constituted by bald cypress and water tupelo trees. The baldcypress are not

majestic because the original trees were removed by logging operations in the early

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1900s. The understory, which is not dense, is composed primarily of swamp red

maple and green ash. The ground is hard bottom. The swamps are perennially wet,

but the water is clear. The setting is tranquil and shaded.

The degraded swamps, which were formerly of the bald cypress-tupelo

type, are located in the low interior areas as the elevations decrease away from the

ridges and dredged material deposits. The canopy has largely or completely

disappeared, eliminating the shading in the surrounding swamp. The ground is

bog-like, with a danger of sinking past hip boots, and the water is covered with

green floating scum. There is a strong odor that smells like decayed matter. The

degraded swamps are decidedly unpleasant from an aesthetic perspective.

View Sheds. The Blind River, Little Bayou Chene Blanc, Bayou

Chene Blanc, and the scenic portions of the Petite Amite River are only observable

by boat within the project area. The Chinquapin Canal is observable from land but

only through streets in Berthelot’s Campground that are separated from the canal

by private properties. The only expansive view of the ARDC (other than by boat) is

from the Hwy. 22 bridge by automobile, but the view is of short duration because it

is dangerous to stop on the bridge.

There are no public views of the interior of the swamps, which are seen

only by a small number of hunters (fewer than 40). The only public thoroughfare in

and around the project area is the ARDC, which is used by recreational boaters.

The view sheds for this portion of the project area include the areas surrounding the

dredged material berm and minimal areas within the interior swamp. These views

are made up mostly of the development along the banks of the canal and some

overgrown portions of the bank; therefore, a majority of the impacts that occur

within the project area would not be noticeable from these view sheds.

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.

Historic Conditions. Recreation activities in the LCA ARDC study area

are centered on natural resources. There was little in the way of recreational

activities in the LCA ARDC study area historically because the area was remote

and opportunities for boating, fishing, and hunting were widespread for people in

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the major population centers such as Baton Rouge and New Orleans. Usage of the

streams for boating and fishing developed gradually as the quality and range of

recreational boats increased, and usage of the swamps for hunting developed

gradually as resources near population centers became scarcer. However, there was

a burst of recreation activity during the post-war economic expansion, which

provided the resources and leisure for higher levels of recreational participation.

The construction of the ARDC opened the area for those higher levels of

participation.

Existing Conditions. Recreation activities in the LCA ARDC study area

are centered on the area’s natural resources. The waterways within and comprising

the boundaries of the LCA ARDC study area are used extensively for recreational

purposes. According to the LDWF (personal communication), the most important of

these activities is pleasure boating, followed by fishing and then by hunting. Water

access is available from private docks along the waterways and from public and

private boat ramps.

4.2.15 Socioeconomics and Human Resources

This resource is institutionally significant because of NEPA; the Estuary Protection

Act; the CWA; 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.

The Final Programmatic Environmental Impact Statement (FPEIS) for the

Louisiana Coastal Area (LCA) Louisiana Ecosystem Restoration Study is

incorporated by reference. The FPEIS deals with the whole of the coastal area and

therefore does not contain information specific to the LCA ARDC study area. The

FPEIS points out that water has traditionally acted as an attractant for settlement.

This is also the situation in the LCA ARDC study area.

4.2.15.1 Population and Housing

Historic Conditions. The Chinquapin Canal was constructed in the

1950s by the Livingston Parish Department of Public Works with the assistance of

the State of Louisiana and discharges water from Old River into Bayou Chene

Blanc. Berthelot’s Campground was developed in the 1960s at the intersection of

the canal and the river (Figure 4.9). The campground was developed on both sides

of the canal and displayed a typical subdivision street pattern. Other than

270
22

22

22

CHINQUAPIN

CAMPSITES

BLIND

RIVER

CAMPSITES

BERTHELOT'S

CAMPGROUND

RIVER

HIGHLANDS

WATERFRONT

WEST

WATERFRONT

EAST

THREE

RIVERS

ISLAND

SANCTUARY SOUTH

PROPOSED

BRIDGE

16

THE WATERFRONT

WATERFRONT

SANCTUARY

Flat

Lake

Bayou Pierre

Old River

Bayou Chene Blanc

Chinquapin Canal

Amite River Diversion Canal

Little Bayou

Chene Blanc

Blind River

Petite Amite River

New River Canal

Bayou Vicknair

New River

Alligator Bayou

St. John

the

Baptist

Parish

Livingston Parish

Ascension Parish

SW-2

SE-1

NW-2

NE-1

NE-2

NW-1

SW-1

SE-2

NE-3

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:

Source: NAIP/GEC

EXISTING AND PROPOSED DEVELOPMENT NEAR THE LCA-ARDC STUDY AREA

Figure: 4.9

1:80,000

Map ID: 27850108-1790

Texas Mississippi

Arkansas

Legend

Existing DevelopmentProposed DevelopmentStudy Area SubunitsState HighwaysParishes

0 0.5 1 1.5 2

Miles

SE-1

Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

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Berthelot’s Campground, the LCA ARDC study area has had little in the way of

population or housing. Development along the dredged material berms has

occurred, leading to an increase in population and residential housing within the

LCA ARDC study area.

Existing Conditions. Development in the LCA ARDC study area is

generally along the ARDC, Amite and Blind Rivers and on ridges (Figure 4.9). The

LCA ARDC study area is located within an area that historically has been known

as Maurepas Island, which is bounded on the north by the Amite River, on the west

by Bayou Pierre, on the south by the Petite Amite and Blind rivers, and on the east

by Lake Maurepas. This designation was apparently used from the earliest

settlement period, because it appears in Act 95 of the 1850 Louisiana Legislature,

which transferred the island from Ascension Parish to Livingston Parish.

The community of Head of Island, which is on the Amite River

immediately west of the LCA ARDC study area, was so named because it is at the

head of this island. The English name and its suggestion of upstream movement

indicate that it was a late landing for boats, although it may have been a stopping

place as early as the 1700s. Mary Ann Sternberg in Winding Through Time: The

Forgotten History and Present-Day Peril of Bayou Manchac indicates that Head of

Island was a landing for steamboats from New Orleans from at least 1868, and it

begins to appear on maps in the 1870s.

The newer housing developments that constitute the distinctive

feature of the ARDC did not begin until the present decade, with Blind River

Properties as one of the major developers. The Blind River Properties is the largest

property holder in the LCA ARDC study area and its environs. The Blind River

Properties owns 32,806 acres along the southwest shore of Lake Maurepas, along

both banks of Blind River, and along the ARDC (Annie Fugler, “Boat-ing in Your

Own Backyard,” Livingston Business and Real Estate Journal, August 2006, pp.7-

9). Approximately 85 to 90 percent is clear cut bald cypress swamp. The balance

consists of higher elevations along various oak ridges, lake shore banks, and canal

dredged material areas.

4.2.15.2 Employment and Income

Historic Conditions. In the past, employment within the LCA ARDC

study area was less than current figures due to limited population and business.

Income levels were also lower than present, due to the socioeconomic makeup of the

local residents. An increase in development has led to increased incomes and

employment. Census information is difficult to interpret for the LCA ARDC study

area due to the differential between the size of the census block and the LCA ARDC

study area.

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Existing Conditions. The permanent-resident population of

Berthelot’s Campground is about 180. About half of the adults are retired. The

non-retired permanent residents work in Baton Rouge, Denham Springs, Gonzales,

and the plants along the Mississippi River. The permanent-resident population of

Waterfront East is about 247. About 30 percent of the adults are retired. The nonretired permanent residents work in Baton Rouge, New Orleans, and Denham

Springs. The permanent-resident population of Three Rivers Island is about 23,

mostly single persons working at the industrial facilities on the Mississippi River.

The unemployment rate was 7.2 percent for Livingston Parish in July 2009. There

is nothing to indicate that the permanent residents of the project area are

experiencing any particular difficulties with respect to employment, although for

sale signs suggest that many were affected by the downturn in the housing market.

Berthelot’s Campground is populated by middle income persons, with

some low income persons. Waterfront East, and particularly the Sanctuary, is

populated by high income persons. The Three Rivers Island Campground is

populated by middle to upper income persons.

4.2.15.3 Community Cohesion

Historic Conditions. Berthelot’s Campground was a well defined

community with good community cohesion since the 1960s. No other communities

existed in the LCA ARDC study area. Therefore, there were no other issues

affiliated with community cohesion.

Existing Conditions. The LCA ARDC study area is populated along

the ARDC, Amite and Blind Rivers, and on adjacent ridges. Community cohesion

must be addressed from the perspective of the LCA ARDC study area and the

individual communities within the LCA ARDC study area. The three communities

within the LCA ARDC study area are Berthelot’s Campground, Waterfront East,

and Three Rivers Island. The Blind River Campsites should not be considered a

potential community because only one camp has been established. The three

communities are internally homogeneous and not related to each other.

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

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is meaningfully greater than in the general population. Low-income populations as

of 2000 are those whose income are $22,050.00 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

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 LCA ARDC

study area are greater than those in the reference community. For purposes of this

analysis, all Census Block Groups within a one mile radius of the project footprint

are defined as the EJ LCA ARDC study area. Livingston Parish, of which the LCA

ARDC Modification project is located, is considered the reference community of

comparison, 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 LCA ARDC 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

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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.

Historic 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 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 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 lowincome 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.

Existing Conditions. The proposed LCA ARDC Modification project

area follows the boundary of the Petite Amite River which borders Ascension and

Livingston Parishes in Louisiana. The LCA ARDC Modification project area is primarily

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freshwater swamp that is sparsely populated, with a few residential streets and

businesses in the northwestern section of the project boundary as well as residences

along the Amite River Diversion Canal.

According to the 2000 U.S. Census, the LCA ARDC Modification project

boundary for Livingston Parish is located within census tract 409.2, and has not changed

from 2000 to 2008. The 2000 Census records indicate that the minority population in

Livingston Parish was 6.3 percent and the low-income population was 11.4 percent.

According to 2008 ESRI estimates (ESRI 2008), 8.2 percent of the population was

minority and the 2007 ESRI estimates indicate 10.8 percent of the population was low

income. The percentage of the population that is minority and low-income in Livingston

Parish is significantly lower than state figures. Per the 2000 U.S. Census data, the LCA

ARDC Modification project area was not a minority and/or low income community in

2000.

4.2.15.5 Infrastructure

Historic Conditions. Little in the way of highway development

existed within the LCA ARDC study area until the 1950s, at which time LA-22 was

constructed (Figure 4.10). The increase in development along the dredged material

berms has led to the development of additional access roads and bridges associated

with these new communities.

Existing Conditions. Plans for a proposed development along the

right descending bank of the ARDC east of the Petite Amite River (as presented in

Coastal Use Permit Application P20060256 [DOA Permit Application MVN-2006-

1335-CZ]) include a new residential access road along the right descending bank

(2.7 miles) and a new bridge that would traverse the ARDC at an elevation of 26 ft

National Geodetic Vertical Datum of 1929 (NGVD 29), approximately 1.5 miles east

of the Petite Amite River (subunit SE-1), for access to the new development. Two

20-foot by 40-foot bridge crossings are proposed along the new residential access

road to coincide with proposed locations for dredged material berm cuts.

Additionally, the U.S. Coast Guard has proposed the construction of a new bridge

across the ARDC at Mile 3.37, near Head of Island, Louisiana (subunits NW-2/SW2). The bridge would be accessed by Homeport Drive and would provide access to

waterfront developments along the ARDC.

4.2.15.6 Business and Industry

Historic Conditions. Within the LCA ARDC study area, little in the

way of business and industry existed over the last 100 years. Some businesses,

including boat launches, bars, and restaurants have formed as a result of

population and housing increases and added infrastructure.

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Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Scale:Source: ESRI/GEC

HIGHWAYS NEAR THE LCA-ARDC STUDY AREA

Map ID: 27850108-1793

Ascension Parish

Livingston Parish

St. James Parish

St. John the Baptist Parish

61

61

22

22

East Baton

Rouge Parish

Lake Maurepas

Mississippi River

10

55

61 51

22

444

70

42

75

73

621

44

928

74

931

942

431

30

3125

933

941

641

18

16

429

932

405

934

935

3188

447

1039

63

427

3089

1

938

3120

1032

429

22

42

42

934

935

1037

51

1:220,000

0246 1

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study AreaParishesInterstateU.S. HighwayState or Local Road

Figure: 4.10

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Existing Conditions. Businesses are generally retail stores and

restaurants. There are only six businesses in the LCA ARDC study area, of which

five are located in Berthelot’s Campground. Val’s marina, bar, restaurant, and

grocery is an old establishment on LA- 22 at the west entrance to the campground

and is oriented toward the campground and campsites along Old River. D&J’s bait

shop is run out of a home and serves campground residents as well as nearby

launches. There are two unnamed sinker cypress lumber mills that mill submerged

logs from bayous and lakes of the region. There is also an unnamed Recreational

Vehicle (RV) park that contains six covered spaces. The Blind River Bar is located

within the LCA ARDC study area south of the ARDC at its confluence with the

Blind River and is accessible only by water. This is the only business in the LCA

ARDC study area other than the businesses in Berthelot’s Campground.

There are no businesses in Waterfront East, Three Rivers Island, and

the Blind River Campsites. However, there are three areas of new businesses

contiguous to the LCA ARDC study area that are important to Waterfront East and

Three Rivers Island and the general area of the ARDC.

4.2.15.7 Traffic and Transportation

Historic Conditions. Little to no traffic and transportation existed

within the LCA ARDC study area until the 1950s, at which time LA-22 was

constructed (Figure 4.10). The increase in development along the dredged material

berms has led to additional vehicular traffic associated with these new

communities. Boat traffic has also increased as a result of increased development,

and the construction of the ARDC and the Chinquapin Canal in the 1950s and

1960s, respectively.

Existing Conditions. State and local roads traverse the LCA ARDC

study area. Traffic is generally confined to residents and recreational visitors.

Louisiana Highways 22 and 16, which were blacktopped in the 1950s, are the major

roads in the vicinity of the LCA ARDC study area. The roads in the LCA ARDC

study area are residential access roads. Berthelot’s Campground contains a

subdivision street pattern. Waterfront East, including The Sanctuary, is served by

a single road (Waterfront East Drive) that parallels the ARDC and runs in back of

the homes on the canal. Waterfront East Drive is accessed through Homeport

Drive, which serves a similar function for Waterfront West and connects with LA22. Three Rivers Island is served by a golf cart path that parallels the ARDC and

runs in back of the camps on the canal. The golf cart path is accessed by River

Highlands Drive, which serves a similar function for the River Highlands

development and connects with LA-22. There is no vehicular access to the Blind

River Campsites.

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4.2.15.8 Public Facilities and Services

Historic Conditions. Little to no public facilities and services

existed within the LCA ARDC study area until increases in development along the

dredged material berms occurred. With these developments, public services such as

wastewater treatment, water service, and electricity were implemented.

Existing Conditions. Public facilities and services generally serve

residents and recreational visitors. The LCA ARDC study area is not serviced by a

municipal sewer system. Wastewater Treatment of Louisiana, Inc. provides sewer

service to the two existing Blind River Properties developments along the left

descending bank of the ARDC. Those properties within the LCA ARDC study area

not receiving sewer service from private companies use septic systems for treatment

and disposal of sewage. DOA Section 10/404 Permits for the two existing Blind

River Properties developments on the left descending bank of the ARDC identify the

locations of four existing sewer treatment facilities (approximately 0.2, 0.5, and 2.0

miles southeast of LA-22 and 2.2 miles east of the Petite Amite River) and six sewer

pump stations (approximately 0.2, 0.5, 1.0, 1.3, 1.7, and 2.0 miles southeast of LA22). A proposed sewer treatment facility within the new Blind River Properties

development on the right descending bank of the ARDC east of the Petite Amite

River is planned for installation approximately 1.3 miles west of the Blind River.

This new development would also receive sewer service from Wastewater

Treatment of Louisiana, Inc.

Mail service is provided through the Maurepas Post Office northeast of

the project area (which is why all of the residences and businesses have Maurepas

addresses). Schools are readily available in Livingston Parish, which has benefitted

from the movement of population to the east out of Baton Rouge.

4.2.15.9 Local Government Finance

Historic Conditions. Historically, government finances within the

LCA ARDC study area were small proceeds directed towards Ascension and

Livingston Parishes. Increased development, as well as increases in income levels,

has led to increases in government finances.

Existing Conditions. Increasing population growth increased local

government finances. There are no incorporated towns within the LCA ARDC study

area and therefore no issues connected with local government finance. Head of

Island and Coteau Bourgeois west of the LCA ARDC study area are not

incorporated.

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4.2.15.10 Tax Revenue and Property Values

Historic Conditions. The development of properties on the dredged

material berms within and outside of the project area, along with increases in

business, have resulted in increased property values and tax revenues for Ascension

and Livingston Parishes.

Existing Conditions. Increasing population growth increases tax

revenue and property values. The development of properties on both banks of the

ARDC within and outside of the LCA ARDC study area has resulted in increased

property values and tax revenues for Livingston Parish.

4.2.15.11 Community and Regional Growth

Historic Conditions. An increase in residential development on the

dredged material berms has led to community and regional growth within the LCA

ARDC study area. Berthelot’s Campground (Figure 4.9) has experienced very little

growth since its inception in the 1960s. Waterfront East and Three Rivers Island

were only recently developed and therefore have experienced absolute growth if

measured from the point of inception and nearly complete growth if measured from

the expected point of completion. These developments and others on the ARDC have

been important factors in the growth of the southern portion of Livingston Parish.

Existing Conditions. Increasing population is resulting in

community and regional growth. The three communities within the LCA ARDC

study area are Berthelot’s Campground, Waterfront East, and Three Rivers Island.

The Blind River Campsites should be considered a potential community because

only one camp has been established. Berthelot’s Campground has experienced very

little growth since its inception in the 1960s. Waterfront East and Three Rivers

Island were only recently developed and, therefore, have experienced absolute

growth if measured from the point of inception and nearly complete growth if

measured from the expected point of completion. Both of these communities are

nearly fully developed in the sense that most of the lots in Waterfront East and

Three Rivers Island have been sold and contain residences or campsites. These

developments and others on the ARDC have been important factors in the growth of

the southern portion of Livingston Parish.

4.2.15.12 Land Use Socioeconomics

Agriculture

Historic Conditions. Historically, a significant amount of

agricultural development existed just beyond the LCA ARDC study area. No

significant agriculture has existed within the LCA ARDC study area.

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Existing Conditions. There is no agricultural or pasturage

acreage in the project area.

Forestry

Historic Conditions. Timber was harvested extensively

throughout the LCA ARDC study area prior to the 1940s (John McKenna, 1975

Louisiana State University Thesis, The Role of Water Transportation in the

Settlement of Bayou Manchac and the Amite River).

Existing Conditions. A timber survey and appraisal was

conducted in 1994 by professional forestry consultants for the 32,806 acres owned

by Blind River Properties. The consultants found that there were no areas of

cypress and tupelo in the swamps with trees of sufficient size and volume to be

considered merchantable. Merchantable size timber (red oak, sweet gum, and ash)

was found only on the ridges, including those in the LCA ARDC study area.

However, marketability was considered doubtful because of inaccessibility. Little

timber harvesting occurs within the LCA ARDC study area. However, submerged

cypress logs are extracted from nearby bayous and lakes and processed by several

local timber mills.

Public Lands

Historic Conditions. In 2001, the Maurepas Swamp Wildlife

Management Area (WMA) was donated by the Richard King Mellon Foundation to

the State of Louisiana (Figure 4.11). This management area consists of 1,742 acres

within the LCA ARDC study area. No other public lands have existed within the

LCA ARDC study area.

Existing Conditions. The LDWF administers the Maurepas

Swamp WMA within the LCA ARDC study area. This WMA consists of 1,742 acres

just north of New River Canal (Figure 4.11).

4.2.15.13 Navigation

Historic Conditions. The construction of the ARDC and the

Chinquapin Canal in the late 1950s and early 1960s respectively, has led to

increased recreational boat navigation.

Existing Conditions. There is minimal commercial navigation in

the LCA ARDC study area. The streams and canals of the project area are used for

recreational boating and fishing, particularly during the summer.

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Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Scale:Source: USDA/GEC

PUBLIC LANDS NEAR THE LCA-ARDC STUDY AREA

Map ID: 27850108-1506

Little Bayou Chene Blanc

Bayou C hene

B

la

n

c

NW-2

SE-1

SW-2

NE-2 NE-1

SE-2

NE-3

Blind River

Amite River Diversion Canal

New River Canal

Petite Amite River

Chinquapin Canal

NW-1

SW-1

Weir

Old RailroadEmbankment

Flat

Lake

Amite River

Petite A mite R vi er

Alligator Bay ou

Bayou Chene Blanc

New River

O ld River

Ba

oy

V

u

ci knair

Heath Bayou

Bayou Pierre

Bayou Antoine

1:80,000

0 0.5 1 1.5 2

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study Area SubunitsMaurepas Swamp Wildlife Management Area

Figure: 4.11

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4.2.15.14 Man-Made Resources

Oil, Gas, Utilities and Pipelines

Historic Conditions. The western Maurepas Swamp has

undergone significant oil and gas exploration activity, particularly in the early to

mid-20th century. However, most oil and gas exploration and production activities

in the region have occurred southwest of the LCA ARDC study area.

Existing Conditions. Data from the LDNR Strategic Online

Natural Resources Information System (SONRIS) (http://sonriswww.dnr.state.la.us/www_root/sonris_portal_1.htm) indicate that oil and gas

production activities within the LCA ARDC study area have been relatively light

and occurred primarily in the late-20th century (Figure 4.12). The oil and gas wells

in the project area are dry holes, plugged and abandoned.

Flood Control and Hurricane Protection Levees

Historic Conditions. Hurricane protection levees have not

been utilized within the LCA ARDC study area. Localized flood control has

consisted of the construction of minor ditches for drainage. The construction of the

Chinquapin Canal in the early 1960s and the ARDC in 1957 was initiated in an

effort to provide flood control within the LCA ARDC study area.

Existing Conditions. The ARDC and the Chinquapin Canal

were both constructed for flood control and drainage. These are the only flood

control measures in the project area. The New River Canal southwest of the project

area conveys water from the Marvin Breaux Pump Station at Gonzales and

discharges into the Petite Amite River at the southwest boundary of the project

area. There are no hurricane protection levees in the study area. Hurricane

protection has been increased beyond the study area by West Lake Shore

Pontchartrain Hurricane Protection Project

4.2.15.15 Natural Resources

Commercial Fisheries

Historic Conditions. Some small, localized commercial

fishery operations have existed within the LCA ARDC study area, including

operations harvesting catfish within the Blind River. Very little commercial fishery

harvesting has taken place within the LCA ARDC study area.

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Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Scale:Source: USDA/GEC

OIL, GAS, AND UTILITIES NEAR THE LCA-ARDC STUDY AREA

Map ID: 27850108-1373

Little Bayou

Chene Blanc

Bayou C hene Blanc NW-2

SE-1

SW-2

NE-2 NE-1

SE-2

NE-3

Blind River

Amite River Diversion Canal

New River Canal

Petite Amite River

Chinquapin Canal

NW-1

SW-1

Weir

Old RailroadEmbankment

Flat

Lake

Amite River

Petite A mite R vi er

Alligator Bay ou

Bayou Chene Blanc

New River

O ld River

Ba oy V u ci knair

Heath Bayou

Bayou Pierre

Bayou Antoine

Ascension Parish

Livingston Parish

St. John

the

Baptist

Parish

1:80,000

0 0.5 1 1.5 2

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Oil and Gas WellsPipelinesStudy Area SubunitsParishes

Figure: 4.12

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Existing Conditions. The LCA ARDC study area provides

some habitat for gulf menhaden and striped mullet, but no commercial fishery for

these species is present. There are little commercial fisheries in the LCA ARDC

study area. A number of catfish are taken by commercial fishermen employing hoop

nets on the Blind River and Petite Amite River. There is also a limited amount of

crabbing on the same streams. There are no oyster leases located within the LCA

ARDC study area.

4.2.16 Hazardous, Toxic, and Radioactive Wastes (HTRW)

The USACE is obligated under 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, would 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.

A Phase I Environmental Site Assessment (ESA) of the LCA ARDC study area was

conducted in accordance with USACE Regulation ER 1165-2-132, Water Resources

Policies and Authorities for HTRW Guidance for Civil Works Projects, 26 June 1992

and the American Society for Testing and Materials (ASTM) Standard E 2247-08

Standard Practice for Environmental Site Assessments: Phase I Environmental Site

Assessment Process for Forestland or Rural Property in order to identify recognized

environmental conditions (REC) located on, or in the vicinity of, the LCA ARDC

study area. See Appendix M

The environmental conditions were evaluated for the LCA ARDC study area by:

• Reviewing Federal, state, and local environmental databases;

• Conducting historical research;

• Interviewing pertinent personnel; and

• Performing a site investigation.

Based on the review of Federal, state, and local environmental databases, historical

research, interviews, and site investigations, the assessment identified two RECs

that may have adversely impacted, or may potentially impact, environmental

conditions in the LCA ARDC study area:

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• Underground Storage Tanks (UST) at the former Chinquapin Grocery,

and

• Aboveground Storage Tank (AST) at Val’s Marina.

A limited HTRW survey was conducted for the LCA ARDC study area to REC sites

or potential REC sites in connection with the LCA ARDC study area. This survey

was performed using the USEPA’s EnviroMapper program and the LDEQ

Geographic Information Systems (GIS) website. Multisystem queries of the

available USEPA and LDEQ databases were used to identify the potential REC

sites located within or in the vicinity of the LCA ARDC study area. Potential REC

sites located within or near the LCA ARDC study area are summarized in

Table 4.11.

Table 4.11. Potential REC Sites Located Within or

Near the LCA ARDC Study Area (USEPA, LDEQ, 2008)

Facility Name Facility Address Database

USEPA Databases

Creative Cajun Cooking 14468 Bayou Terrace, St. Amant NPDES

Island Car Wash 14989 Hwy. 16, French Settlement NPDES

Island Car Wash 18961 LA Hwy. 22, Maurepas NPDES

Mecca Inn Restaurant and

Lounge 14365 Mecca Rd., French Settlement NPDES

Swamp Pop Café 18897 LA Hwy. 22, Maurepas NPDES

Island Car Wash Unknown NPDES

Val’s Marina, LLC 21162 LA Hwy. 22, Maurepas NPDES

Don Stout 13027 Deer St., Maurepas RCRAGN

LDEQ Databases

Best Stop Quick Mart #12 15250 Hwy. 16, French Settlement RUST

Brian’s Superette 18886 LA Hwy. 22, Maurepas RUST

Fisherman’s One Stop 45273 LA Hwy. 22, St. Amant RUST

Thunder Bayou Marina 11191 River Highlands Dr.,

St. Amant RUST

Weedy’s Pitt Stop 18985 LA Hwy. 22, Maurepas RUST

Note: Facilities located within LCA ARDC study area are denoted by bold font.

Information gathered during Phase I ESA within LCA ARDC study area

(Appendix L).

Investigations were conducted within a one mile radius surrounding the LCA ARDC

study area.

A review of various Federal and state databases (i.e., USEPA, Notice of Proposed

License Action [NPLA], CERCLA, No Further Response Action Plan [NFRAP],

RCRA Corrective Action Sites [CORRACTS], Resource Conservation and Recovery

Act Generator [RCRAGN], RCRA TSD, National Pollution Discharge Elimination

System [NPDES], and Toxic Release Inventory (TRI) databases; LDEQ Landfills

Type I and II, RUST, and Motor Fuel UST Active 2005 databases) indicates that

none of the potential REC sites listed in Table 4.11 would be likely to expose the

public or construction workers to HTRW or to adversely affect the project.

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5.0 ENVIRONMENTAL CONSEQUENCES

This section describes the potential environmental consequences of implementing

alternative plans to reverse the trend of degradation in the western portion of the

Maurepas Swamp. The following analysis compares the No-Action Alternative

(future without project conditions) to the final array of alternatives over the 50-year

period of analysis (2012 - 2062). The final array of alternatives includes

Alternatives 33, 34, 35, 36, 37, 38 and 39 (see Section 2 for detailed descriptions).

Alternative 33 was the Tentatively Selected Plan (TSP) and was later confirmed as

the Recommended Plan. Alternative 39 is the National Ecosystem Restoration

(NER) Plan.

A comparison of the direct, indirect, and cumulative impacts for alternatives to

reverse the trend of degradation in the western portion of the Maurepas Swamp is

presented herein. Direct impacts are effects caused by the proposed action that

occur at the same time and place (Section 1508.8(a) of 40 CFR Parts 1500-1508).

Indirect impacts are effects caused by the action that occur later in time or further

removed in distance, but are still reasonably foreseeable (Section 1508.8(b) of

40 CFR Parts 1500-1508). Cumulative impacts are effects that result 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).

The cumulative impact analysis followed the 11-step process described in the

Council of Environmental Quality 1997 report entitled Considering Cumulative

Effect under the National Environmental Policy Act. Table 5.1 summarizes

cumulative impacts for each of the alternatives in the final array of alternative

plans across all important resources.

This environmental analysis evaluates and compares, from a qualitative and

quantitative perspective, the alternatives carried over for detailed analysis. Impact

analysis described in this section is based on a combination of scientific and

engineering analyses, professional judgment, field investigations, and previously

compiled information.

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5.1 SOILS AND WATERBOTTOMS

5.1.1 Soils

5.1.1.1 No-Action Alternative

Direct. No direct impacts to soil resources would occur.

Indirect. Indirect impacts would include the continued erosion and land loss

that would continue throughout the study area, eroding primarily Barbary, Fausse,

and Maurepas soils. Most of the erosion would occur in the interfaces between open

water with marsh and/or upland habitat. Soils would be indirectly impacted by

habitat conversion from swamp to marsh and the eventual loss of existing soil

resources converting to shallow open water.

Cumulative. Loss of soil resources from the study area would continue, in

addition to the loss of soil resources throughout coastal Louisiana. The Louisiana

Coastal Area (LCA) Near-term Ecosystem Restoration Plan (U.S. Army Corps of

Engineers [USACE], 2004) estimated coastal Louisiana would continue to lose land

at a rate of approximately 6,600 acres per year over the next 50 years. It is

estimated that an additional net loss of 328,000 acres may occur by 2050, which

represents nearly 10 percent of Louisiana's remaining coastal wetlands. However,

these impacts to wetland soils within the study area and vicinity would be offset to

some extent by other Federal, state, local, and private restoration efforts across

coastal Louisiana (Figure 5.1 and Table 5.2). Overall cumulative impacts include

the conversion of 18,204 acres of swamp to a shallow open water system, which

would be additive with other swamp losses and degradation impacts to soils

throughout the region and state. This acreage represents the total area, which is

predicted to convert from freshwater swamp and marsh to open water over the 50-

year period of analysis, as shown in Figure 2.2.

5.1.1.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts to soil resources would result from construction

activities associated with the removal of the existing dredged material berm along

the Amite River Diversion Canal (ARDC), dredging of new conveyance channels, as

well as the placement of dredged material to create Bottom Land Hardwood (BLH)

"islands" along dredged conveyance channels. Implementation of Alternative 33

would remove approximately 2.6 acres of the existing ARDC dredged material

berms. The material dredged from the existing berms would be placed along the

swamp-side of the excavated cut as 5.0 acres of new BLH habitat "islands."

Dredging of the conveyance channels would remove approximately 28.6 acres of soil

from the swamp floor. All material dredged during construction of the conveyance

channels would be placed along the channels to also create BLH habitat "islands,”

approximately 9.9 acres. The BLH "islands" would be located to allow sufficient

sheet flow to be conveyed from the swamp. The excavation and placement of

dredged materials would directly release sediments into the ARDC and adjacent

swamp. Sediment introduction would temporarily increase total suspended and

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Soil andWaterbottomsSoils

US: Institutional recognition of importance of soilsvia formation of Natural Resources ConservationService (SoilConservation Service)LA: Louisiana coastal land loss of over 1.22 million

acres since 1956.SA: Loss of 1,600 acres in Amite/Blind River

mapping unit between 1932 and 1990 (LCWCRTFand WCRA, 1999).

US, LA, and SA: Continued institutional

recognition; continued loss of soil resources.Natural processes of parent material, climate,organisms, relief, and time factors in soilformation.LA: Continued land loss of over 25 square miles

per year.SA: Continued land loss due to natural and

human-induced causes. Barbary, Fausse, andMaurepas soils are primarily affected.

US, LA, and SA: Continued institutional recognition;

continued loss of soil resources.SA: Shoreline erosion and land loss persist resulting in the

loss of soil resources. Over 50-year period of analysis;

projected conversion of 18,204 acres of swamp soils to freshmarsh and open water. Barbary, Fausse, and Maurepas soilswould primarily be affected.

US & LA: Continued institutional recognition and programs for soil conservation to reduce soil losses.

ALT 33 (Recommended Plan): This alternative would have positive effects on soil resources when combined with other

Federal, state, local, and private restoration efforts. A net total of 1,602 acres of wetland soils would be hydrologically

restored and nourished; 2.6 acres of soils along ARDC berms and 28.6 acres of existing swamp soils would be impactedby construction of conveyance channels, however these sediments would be used to construct 5.0 acres of "BLHislands".ALT 34: Cumulative impacts similar to ALT 33 (RECOMMENDED PLAN). A net total of 1,459 acres wetland soils

would be hydrologically restored and nourished; 3.4 acres ARDC berm soils and 15.4 acres of existing swamp soilswould be impacted and used to construct 2.7 acres of "BLH islands".ALT 35: Cumulative impacts similar to ALT 33. A net total of 820 acres wetland soils would be hydrologically restoredand nourished; 2.4 acres ARDC berm soils and 10.9 acres of existing swamp soils would be impacted and used toconstruct 2.2 acres of "BLH islands".ALT 36: Cumulative impacts similar to ALT 33. A net total of 3,061 acres wetland soils would be hydrologicallyrestored and nourished; 6.0 acres ARDC berm soils and 44.0 acres of existing swamp soils would be impacted and usedto construct 7.8 acres of "BLH islands".ALT 37: Cumulative impacts similar to ALT 33. A net total of 2,279 acres wetland soils would be hydrologicallyrestored and nourished; 5.8 acres ARDC berm soils and 26.3 acres of existing swamp soils would be impacted and usedto construct 4.9 acres of "BLH islands".ALT 38: Cumulative impacts similar to ALT 33. A net total of 2,422 acres wetland soils would be hydrologicallyrestored and nourished; 5.0 acres ARDC berm soils and 39.5 acres of existing swamp soils would be impacted and usedto construct 7.2 acres of "BLH islands".ALT 39: Cumulative impacts similar to ALT 33. A net total of 3,881 acres wetland soils would be hydrologicallyrestored and nourished; 8.4 acres ARDC berm soils and 54.9 acres of existing swamp soils would be impacted and usedto construct 9.9 acres of "BLH islands".

Soils and Waterbottoms-Water

bottoms

US, LA, & SA: Water bottoms develop in response

to natural and man-made conditions.

SA: Construction of the ARDC and side-castdredged material berms restricts hydrologicconnectivity and impounds swamp habitat.

US & LA: Continuing land loss results inincreasing acreage of shallow open water andwater bottoms.SA: Increasing acreages of water bottoms due to

conversion of swamp habitat to freshwater marshand open water habitats.

US & LA: Increased acreage of shallow water bottoms inresponse to wetland loss.

SA: Continued conversion of swamp to freshwater marsh and

open water.

US & LA: Increased acreage of shallow water bottoms in response to wetland loss.ALT 33 (Recommended Plan): This alternative would have positive effects on water bottoms when combined with

other Federal, state, local, and private restoration efforts. Reestablishing hydrologic connections would aid inrestoring swamp habitat and would decrease acreage of water bottoms within the swamp; construction of conveyancechannels would create 18.6 acres of water bottom habitats.ALT 34: Cumulative impacts would be similar to ALT 33 except would create 10.5 acres of water bottom habitats.

ALT 35: Cumulative impacts would be similar to ALT 33 except would create 7.2 acres of water bottom habitats.

ALT 36: Cumulative impacts would be similar to ALT 33 except would create 29.1 acres of water bottom habitats.

ALT 37: Cumulative impacts would be similar to ALT 33 except would create 17.7 acres of water bottom habitats.

ALT 38: Cumulative impacts would be similar to ALT 33 except would create 25.8 acres of water bottom habitats.ALT 39: Cumulative impacts would be similar to ALT 33 except would create 36.3 acres of water bottom habitats.

Hydrology–

Flow and WaterLevels

US & LA: Flows and water levels respond tonatural conditions and man-made conditions.SA: Decreased flows into and out of the swamp due

to construction of dredged material berms alongARDC.

US & LA: Increased flows and water levels withincreased runoff due to increasing urbanizationand wetland loss. Rate of RSLR increasing overhistoric conditions.SA: Decreased flows into and out of the swamp due

to dredged material berms along ARDC. Increasedrunoff due to increased urbanization of thePontchartrain Basin.

US & LA: Increased flows and water levels with increasedurbanization and associated runoff and increased wetlandloss. Rate of RSLR increasing over historic conditions.SA: Decreased flows into and out of the swamp due to

dredged material berms along ARDC. Increased water levelsdue to coastal wetland loss, and increased runoff due toincreased urbanization of the Pontchartrain Basin.

US & LA: Increased flows and water levels with increased urban runoff from increasing urbanization and increasedwetland loss. Rate of RSLR increasing over historic conditions.

ALT 33 (Recommended Plan): This alternative would have positive effects on water levels and flows when combined

with other Federal, state, local, and private restoration efforts. Three cuts in the ARDC dredged material berm would

reconnect the hydrology and increase flows into and out of 1,602 acres of swamp; water levels fluctuate in response toARDC and sea level rises.ALT 34: Cumulative impacts would be similar to ALT 33 except one cut reconnect hydrology of 1,459 acres.ALT 35: Cumulative impacts would be similar to ALT 33 except one cut reconnect hydrology of 820 acres.

ALT 36: Cumulative impacts would be similar to ALT 33 except four cuts reconnect hydrology of 3,061 acres.

ALT 37: Cumulative impacts would be similar to ALT 33 except two cuts reconnect hydrology of 2,279 acres.

ALT 38: Cumulative impacts would be similar to ALT 33 except four cuts reconnect hydrology of 2,422 acres.

ALT 39: Cumulative impacts would be similar to ALT 33 except five cuts reconnect hydrology of 3,881 acres.

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Hydrology–

Sediment

US: Decreasing sedimentation due to reduction oferosion on land, reservoirs, and stream banks bystabilization.LA & SA: Sediment delivery by crevasses ended

after Flood Control Act of 1928.

SA: Decreased redistribution of sediments into and

out of the swamp due to dredged material bermsalong ARDC. Amite River is primary source ofsediments.

US: Decreasing sedimentation due to reduction of

erosion on land, reservoirs, and stream banks bystabilization.LA & SA: Inflow of suspended sediments byMississippi River limited by construction of levees.

SA: Decreased redistribution of sediments into andout of the swamp due to dredged material bermsalong ARDC.

US: Continued decreasing sedimentation due to reduction of

erosion.LA: Sediment supply would not offset coastal land loss.

SA: Storms cause some redistribution of sediments to and

from the swamp and surrounding water, but the ARDCdredged material berm would continue to block exchange andtherefore sedimentation. The swamp would continue todeteriorate due to this impoundment and lack of sediment

supply.

US & LA: Continued decreasing sedimentation due to reduction of erosion.

ALT 33 (Recommended Plan): This alternative would have positive effects on hydrology sediments when combined

with other Federal, state, local, and private restoration efforts. Reconnected hydrology increases potential forsediment inputs into 1,602 acres.ALT 34: Cumulative impacts would be similar to ALT 33 except increased potential for 1,459 acres.

ALT 35: Cumulative impacts would be similar to ALT 33 except increased potential for 820 acres.

ALT 36: Cumulative impacts would be similar to ALT 33 except increased potential for 3,061 acres.

ALT 37: Cumulative impacts would be similar to ALT 33 except increased potential for 2,279 acres.

ALT 38: Cumulative impacts would be similar to ALT 33 except increased potential for 2,422 acres.

ALT 39: Cumulative impacts would be similar to ALT 33 except increased potential for 3,881 acres.

Hydrology–

Water Use andSupply

US, LA, & SA: Increasing surface water use and

supply demands due to increasing humanpopulations, agriculture and industry uses.

SA: No significant surface water use or supply

issues for humans.

US, LA, & SA: Continued increasing demands for

surface water use and supply due to increasinghuman populations, agriculture and industry uses.

SA: No significant surface water uses or supply

issues for humans; conversion of swamp habitat toopen water habitat reduces water purificationfunction of forested wetlands.

US, LA, & SA: Continued increasing demands for surfacewater use and supply due to increasing human populations,agriculture and industry uses.SA: Continued conversion of swamp habitat to open waterhabitat reduces water purification function of wetlandsindirectly impacting human uses.

US & LA: Continued increasing demands on surface water use and supply due to increasing human populations,agriculture and industry uses.ALT 33 (Recommended Plan): Continued increase in human water use and supply demands; reconnected hydrology

improves water purification function over 1,602 acres swamp.ALT 34: Cumulative impacts would be similar to ALT 33 except improves purification function of 1,459 acres.

ALT 35: Cumulative impacts would be similar to ALT 33 except improves purification function of 820 acres.ALT 36: Cumulative impacts would be similar to ALT 33 except improves purification function of 3,061 acres.

ALT 37: Cumulative impacts would be similar to ALT 33 except improves purification function of 2,279 acres.

ALT 38: Cumulative impacts would be similar to ALT 33 except improves purification function of 2,422 acres.

ALT 39: Cumulative impacts would be similar to ALT 33 except improves purification function of 3,881 acres.

Hydrology–

Groundwater

US, LA, & SA: Increasing demands forgroundwater by increasing human populations,agriculture, and industry.

SA: Groundwater is not an issue of concern;

groundwater is primarily from the ChicotEquivalent aquifer.

US, LA, & SA: Decreased groundwater resourcesdue to increasing demands by increasing humanpopulations, agriculture, and industry.

SA: Groundwater is not an issue of concern;

groundwater is primarily from the ChicotEquivalent aquifer.

US, LA, & SA: Decreased groundwater resources due toincreasing demands by increasing human populations,agriculture, and industry.

SA: Groundwater is not an issue of concern; groundwater isprimarily from the Chicot Equivalent aquifer.

US & LA: Decreased groundwater resources due to increasing demands by increasing human populations, agriculture,and industry.ALT 33 (Recommended Plan): This alternative would have little to no impact on groundwater, which is primarily

taken from the Chicot Equivalent aquifer.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Water Quality

US & LA, SA: Clean Water Act of 1977, NEPA of

1969, Coastal Zone Management Act, and EstuaryProtection Act institutional recognition to restoreand protect water bodies, especially with respect topoint sources. Non-point sources still unregulated.SA: Human developments along the ARDC, Amite

and Blind Rivers and on ridges begin to adverselyimpact water quality. The ARDC northeast ofSorrento is listed as impaired for mercury.

US, LA, & SA: Continued institutional recognition.

Increasing human populations, agriculture andindustrialization result in increased potential forwater quality problems.

SA: Human developments result in wastewater

and polluted runoff from nearby urban areas;continued conversion of swamp habitat to marshand open water reduces natural filtration of water.

US, LA & SA: Continued institutional recognition. Increasing

human populations and industrialization result in increasedpotential for water quality problems.

SA: Conversion of 18,204 acres of swamp to marsh and open

water reduces natural filtration of water by swampvegetation; continued discharge of untreated stormwaterrunoff from nearby populated areas.

US, LA & SA: Continued institutional recognition. Increasing human populations and industrialization result in

increased potential for water quality problems.ALT 33 (Recommended Plan): This alternative would have positive effects on water quality when combined with other

Federal, state, local, and private restoration efforts. Temporary negative impacts (e.g., increased turbidity, decreaseddissolved oxygen (DO)) during construction. Water quality improves over 1,602 acres of swamp habitat due toincreased hydrologic connectivity as well as absorption and filtering of untreated stormwater runoff from nearbypopulated areas.ALT 34: Cumulative impacts would be similar to ALT 33 except 1,459 acres.

ALT 35: Cumulative impacts would be similar to ALT 33 except 820 acres.

ALT 36: Cumulative impacts would be similar to ALT 33 except 3,061 acres.

ALT 37: Cumulative impacts would be similar to ALT 33 except 2,279 acres.

ALT 38: Cumulative impacts would be similar to ALT 33 except 2,422 acres.ALT 39: Cumulative impacts would be similar to ALT 33 except 3,881 acres.

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WRDA 2007 Section 7006(e)(3) October 2010 5-5

Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Water Quality –Salinity

US & LA: Increase in salinity levels inland due tosalt water intrusion, due in part to wetlands loss.SA: Construction of ARDC results in impounding

storm driven higher salinity waters within SA andcauses it to absorb into the substrate resulting indegradation of freshwater swamp ecosystem.

US & LA: Increase in salinity levels inland due tosalt water intrusion from wetlands loss andreduction in freshwater inflow.SA: Continued impounding of higher salinity

waters causing it to absorb into the substrateresulting in degradation of freshwater swampecosystem.

US & LA: Increase in salinity levels inland due to salt waterintrusion from wetlands loss and reductions in freshwaterinflow. Salinities may also increase due to projected relativesea level rise.SA: Continued impoundment and lack of hydrologic

connections result in longer residence time of higher salinitywater resulting in absorption of salinity into swamp soilscontinuing the degradation of freshwater swamp and BLHvegetation.

US & LA: Increase in salinity levels inland due to salt water intrusion from wetlands loss and reductions infreshwater inflow. Salinities may also increase due to projected RSLR.

ALT 33 (Recommended Plan): This alternative would reduce salinity when combined with other Federal, state, local,

and private restoration efforts. Restored hydrologic connectivity of 1,602 acres would reduce impoundment of highersalinity waters.ALT 34: Cumulative impacts would be similar to ALT 33 except restored hydrologic connectivity of 1,459 acres.

ALT 35: Cumulative impacts would be similar to ALT 33 except restored hydrologic connectivity of 820 acres.

ALT 36: Cumulative impacts would be similar to ALT 33 except restored hydrologic connectivity of 3,061 acres.

ALT 37: Cumulative impacts would be similar to ALT 33 except restored hydrologic connectivity of 2,279 acres.ALT 38: Cumulative impacts would be similar to ALT 33 except restored hydrologic connectivity of 2,422 acres.

ALT 39: Cumulative impacts would be similar to ALT 33 except restored hydrologic connectivity of 3,881 acres.

Air Quality

US, LA, & SA: Institutional recognition via CleanAir Act of 1963.LA & SA: Institutional recognition via LouisianaEnvironmental Quality Act of 1983. Formation ofUSEPA and LDEQ.SA: not an issue.

US, LA, & SA: Continued institutional recognition;deterioration of air quality in the region due toincreases in human populations and industry.LA, & SA: These impacts are coupled with the loss

of Louisiana coastal wetland vegetation that is no

longer available to remove gaseous pollutants.SA: Human development along the ARDC, Amite

and Blind Rivers and on ridges. In nonattainmentarea for ozone.

US, LA, & SA: Continued institutional recognition; continueddeterioration of air quality due to continued populationgrowth and increased industrialization.LA, & SA: These impacts would be coupled with the

continued loss of Louisiana coastal wetland vegetation that

would no longer be available to remove gaseous pollutants.SA: Conversion of 18,204 acres of swamp vegetation to fresh

marsh and open water habitat over 50-year period of analysisreduces function of swamp vegetation to act as natural filterfor air pollutants.

US & LA: Continued institutional recognition; continued deterioration of air quality due to continued populationgrowth and increased industrialization.ALT 33 (Recommended Plan): This alternative would have positive effects on air quality when combined with other

Federal, state, local, and private restoration efforts. Restoration of 1,602 acres freshwater swamp habitat may act asnatural filters for air pollutants.ALT 34: Cumulative impacts would be similar to ALT 33 except restoration of 1,459 acres.ALT 35: Cumulative impacts would be similar to ALT 33 except restoration of 820 acres.

ALT 36: Cumulative impacts would be similar to ALT 33 except restoration of 3,061 acres.ALT 37: Cumulative impacts would be similar to ALT 33 except restoration of 2,279 acres.ALT 38: Cumulative impacts would be similar to ALT 33 except restoration of 2,422 acres.ALT 39: Cumulative impacts would be similar to ALT 33 except restoration of 3,881 acres.

Noise

US, LA, & SA: Institutional recognition via NoiseControl Act of 1972.SA: Noise pollution sources are development along

the ARDC, Amite, and Blind Rivers, on ridges, andboat traffic on ARDC, Amite and Blind Rivers.Noise is not yet an issue.

US, LA, and SA: Continued institutionalrecognition; continued human population growthand development cause some noise pollution.SA: Ambient noise from boats and airboats onARDC, Amite and Blind Rivers, and other humanactivities may cause some minimal and temporarydisturbances.

US, LA, and SA: Continued institutional recognition;

continued human population growth and development would

cause some noise pollution.SA: Ambient noise from boats and airboats on ARDC, Amite

and Blind Rivers, and other human activities continue tocause some minimal and temporary disturbances.

US & LA: Continued institutional recognition; continued human population growth and development would causesome noise pollution.ALT 33 (Recommended Plan): Short term, localized and temporary increased noise associated with construction

activities. Long term, impacts similar to No-Action Alternative.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Vegetation -RiparianVegetation

US, LA, & SA: Natural processes form coastal

vegetation resources. Riparian vegetation is

located at the interface of land and a flowing waterbody.

SA: Construction of ARDC results in creation of

riparian habitat along dredged material berms

along the ARDC as well as the banks of other waterbodies.

US, LA, & SA: Deterioration and loss of wetlandsnationwide and statewide.SA: Riparian habitat is primarily limited to the

dredged material berms along the ARDC and thebanks of other water bodies. Saltwater intrusionfrom storm events has additionally stressed theswamp habitat along the Blind River.

US, LA, and SA: Continued deterioration and loss of

vegetated wetland habitat acreage due to natural andhuman-induced processes.SA: Riparian vegetation along ARDC berms likely unchanged

over 50-year period of analysis.

US & LA: Continued institutional recognition and programs for soil conservation to reduce soil losses.ALT 33 (Recommended Plan): This alternative would have positive effects on riparian vegetation when combined with

other Federal, state, local, and private restoration efforts. There would be creation of riparian habitat alongconveyance channels. Riparian vegetation on dredged material berms would be impacted by construction.ALTS 34-39: Cumulative impacts similar to ALT 33.

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

VegetationWetlandVegetation

US, LA, & SA: Natural processes form coastal

wetland vegetation resources.SA: Degradation of approximately 26,493 acres ofprimarily bald cypress-tupelo swamp habitat,

leaving approximately 18,204 acres in theAmite/Blind River mapping unit.

US, LA, & SA: Deterioration and loss of wetlandsnationwide and statewide due to natural andhuman-induced processes.SA: About 18,204 acres of primarily bald cypresstupelo swamp habitat are presently impounded todiffering levels. Existing swamp habitatsconverting to marsh and shallow open waterhabitats. Saltwater intrusion from storm eventshas additionally stressed the swamp habitat alongthe Blind River.

US, LA, and SA: Continued deterioration and loss of

vegetated wetland habitat acreage due to natural andhuman-induced processes.SA: Conversion of 18,204 acres of existing swamp to fresh

marsh and open water over 50-year period of analysis.

US & LA: Continued deterioration and loss of vegetated wetland habitat acreage due to natural and human-induced

processes.ALT 33 (Recommended Plan): This alternative would have positive effects on wetland vegetation resources when

combined with other Federal, state, local, and private restoration efforts. A net total of 1,602 acres of primarily baldcypress-tupelo swamp habitat would be restored and nourished. Vegetation reduces shoreline erosion and potentiallyhelps future healthy productive swamps to accrete sediments at rates near or equal to local sea level rise, such thatlocalized relative subsidence may also be reduced. Additionally, the enhanced wetland acreage would provide some

protection to ecosystems inland from the study area, potentially reducing loss rates.ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres swamp habitat restored and nourished.

ALT 35: Cumulative impacts similar to ALT 33 except 820 acres swamp habitat restored and nourished.ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres swamp habitat restored and nourished.ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres swamp habitat restored and nourished.

ALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres swamp habitat restored and nourished.ALT 39: Cumulative impacts similar to ALT 33 except 3,881acres swamp habitat restored and nourished.

VegetationUplandVegetation

US, LA, & SA: Natural processes form coastal

vegetation resources.SA: Upland habitat is primarily limited to thedredged material berms along the ARDC.

US, LA, & SA: Deterioration and loss of uplands

nationwide and statewide.SA: Upland habitat is primarily limited to the

dredged material berms along the ARDC and thebanks of other water bodies in the area.

US, LA, & SA: Continued deterioration and loss of vegetated

upland habitat acreage due to natural and human-induced

processes.SA: The upland vegetation would convert to unstable

freshwater marsh, which in turn would convert to openwater.

US & LA: Continued deterioration and loss of vegetated wetland habitat due to natural and human-induced processes.

ALT 33 (Recommended Plan): This alternative would have little effect on upland vegetation when combined withother Federal, state, local, and private restoration efforts. Upland vegetation located on dredged material berms alongthe ARDC would be impacted by construction.ALTS 34-39: Cumulative impacts similar to ALT 33.

VegetationSubmerged

AquaticVegetation(SAV)

US, LA, & SA: Natural and man-influencedprocesses form SAVs.SA: SAVs limited to shallow areas with flow that ishigh enough to keep the area clear of floatingspecies within the ARDC and other water bodies.

US, LA, & SA: Deterioration and loss of wetlands

nationwide and statewide.SA: SAVs limited to shallow areas with flow that

is high enough to keep the area clear of floatingspecies within the ARDC and other water bodies.

US, LA, and SA: Continued deterioration and loss of

vegetated wetland habitat acreage due to natural andhuman-induced processes.SA: Conversion of 18,204 acres swamp vegetation to fresh

marsh and open water habitat with little to no flow over 50-year period of analysis. Associated poor water quality likelynot conducive to growth of SAVs.

US & LA: Continued deterioration and loss of vegetated wetland habitat due to natural and human-induced processes.ALT 33 (Recommended Plan): This alternative would have positive effects on SAVs when combined with other

Federal, state, local, and private restoration efforts due to the creation of more shallow, flowing habitat in the swamp

interior. Reconnecting hydrology to 1,602 acres of swamp makes conditions conducive for SAV.ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres reconnected.ALT 35: Cumulative impacts similar to ALT 33 except 820 acres reconnected.ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres reconnected.ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres reconnected.ALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres reconnected.ALT 39: Cumulative impacts similar to ALT 33 except 3,881 acres reconnected.

VegetationInvasive Species

US, LA, & SA: Natural processes form coastal

vegetation resources. Invasive species have beenintentionally and unintentionally released and areoutcompeting native vegetation species andspreading throughout many habitat types.

US, LA, & SA: Continued spread of invasive

species throughout many habitat types.SA: The spread of invasive species continues to

alter ecosystem function by decreasing nativeplant communities.

US, LA, and SA: Continued spread of invasive species

throughout many different habitats. Continued deteriorationand loss of vegetated wetland habitat acreage due to naturaland human-induced processes.SA: Conversion of 18,204 acres of swamp vegetation to fresh

marsh and open water habitat. Invasive species wouldcontinue to spread throughout.

US & LA: Continued spread of invasive species throughout many different habitats. Continued deterioration and lossof vegetated wetland habitat acreage due to natural and human-induced processes.ALT 33 (Recommended Plan): This alternative would increase invasive vegetation spread when combined with other

Federal, state, local, and private restoration efforts due to the habitat disturbance from construction efforts.Reconnecting hydrology to 1,602 acres of swamp makes conditions conducive for invasive species to spread further.ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres reconnected.ALT 35: Cumulative impacts similar to ALT 33 except 820 acres reconnected.ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres reconnected.

ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres reconnected.ALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres reconnected.ALT 39: Cumulative impacts similar to ALT 33 except 3,881 acres reconnected.

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WRDA 2007 Section 7006(e)(3) October 2010 5-7

Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

WildlifeResources

US, LA, & SA: Wetland dependent wildlifepopulations respond primarily to naturalpopulation-regulating mechanisms.

SA: The bald eagle was removed from the

endangered species list in 2007, but is currentlyundergoing five years of monitoring to confirm therevised status. The Southeast United States

Regional Waterbird Conservation Plan wascompleted in 2006.

US, LA, & SA: Continued nationwide degradationand loss of wetlands leads to decline of wetlanddependent wildlife populations.SA: Continued swamp degradation and conversion

to marsh and open water leads to increasedcompetition between local wetland-dependentwildlife populations, displacement to other moresuitable swamp wetland areas, and localizeddecline in wetland-dependent wildlife population.

Bald eagle populations in the area are steady. Abald eagle nesting site is located within the studyarea. Habitat for wading birds in the area are

declining due to swamp degradation

US, LA, and SA: Nationwide degradation and loss of swamp

habitat continues to adversely impact wetland-dependent

wildlife populations.SA: Conversion of 18,204 acres of swamp vegetation to fresh

marsh and open water habitat resulting in continued declinein quality of and availability of swamp wildlife habitat.Conversion of swamp to open water will adversely affectpopulations of bald eagle and colonial nesting wading birdsdue to decreased nesting habitat and decreased foodavailability.

US & LA: Continued nationwide loss of vegetated wetlands continues to adversely impact wetland-dependent wildlifepopulations.ALT 33 (Recommended Plan): This alternative would have positive effects on wildlife resources when combined with

other Federal, state, local, and private restoration efforts. Creation and nourishment of a net total of 1,602 acres ofwildlife habitats. Migratory neo-tropical songbirds and waterfowl could increase as important migratory habitat is

created and nourished. Although unlikely to impact wildlife populations on a continental scale, local populations ofgame animals, furbearers, reptiles, amphibians, and invasive species (especially nutria) would benefit from thecumulative effects of creating and nourishing important and essential transitional wetlands. Local populations of the

bald eagle and colonial nesting wading birds would benefit from the cumulative effects of creating and nourishingwetlands.

ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres swamp habitat created and nourished.ALT 35: Cumulative impacts similar to ALT 33 except 820 acres swamp habitat created and nourished.ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres swamp habitat created and nourished.

ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres swamp habitat created and nourished.ALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres swamp habitat created and nourished.

ALT 39: Cumulative impacts similar to ALT 33 except 3,881 acres swamp habitat created and nourished.

AquaticResources -Plankton

US & LA: Institutionally recognized by theNational Environmental Policy Act of 1969, theCoastal Zone Management Act, and the EstuaryProtection Act. Plankton populations respond tonatural conditions.SA: Construction of the ARDC resulted in dredged

material berms which limits exchange of organismsand water between the swamp and the ARDC.

US: Continued institutional recognition.Populations respond to natural and humaninduced perturbations.LA: Populations in LA are shifting towards more

saline-oriented species as land loss and saltwaterintrusion into interior regions continues.SA: Plankton population changes associated with

conversion of swamp habitat to freshwater marshand open water.

US: Continued institutional recognition. Populations

continue to respond to natural and human-inducedperturbations.LA: Populations in LA are shifting towards more salineoriented species as land loss and saltwater intrusion intointerior regions continues.

LA & SA: Conversion of swamp to fresh marsh and openwater may shift populations, but there are no direct adverseimpacts.

US & LA: Continued institutional recognition. Continued nationwide loss of vegetated wetlands continues toadversely impact wetland-dependent wildlife populations.ALT 33 (Recommended Plan): This alternative would have positive effects on plankton resources when combined with

other Federal, state, local, and private restoration efforts. The creation of conveyance channels in concert withwetland creation and nourishment would result in greater productivity of plankton organisms due to the export ofdissolved organic compounds.ALTS 34-39: Cumulative impacts similar to ALT 33.

Aquatic

ResourcesBenthic

US, LA, & SA: Benthic populations respond tonatural and to human induced conditions.SA: Construction of the ARDC resulted in dredged

material berms which limits exchange of benthicorganisms and water between the swamp and theARDC.

US & LA: Increased acreage of shallow waterbottoms in response to wetland loss. Benthicpopulations respond to natural and humaninduced perturbations with shift towards moresaline-oriented species as land loss and saltwaterintrusion into interior regions continues.SA: Benthic population changes associated with

conversion of swamp habitat to freshwater marshand open water.

US & LA: Increased acreage of shallow water bottoms inresponse to wetland loss. Benthic populations respond tonatural and human-induced perturbations with shift towardsmore saline-oriented species as land loss and saltwaterintrusion into interior regions continues.SA: Conversion of swamp to freshwater marsh and open

water may shift benthic populations. The amount of habitatavailable for use by benthic species assemblages thattypically utilize swamp or marsh edge habitats woulddecrease. The availability of nutrients and detritus from thedecomposing swamp vegetation would initially increase, andthen decrease.

US & LA: Increased acreage of shallow water bottoms in response to wetland loss. Benthic populations respond tonatural and human-induced perturbations with shift towards more saline-oriented species as land loss and saltwater

intrusion into interior regions continues.

ALT 33 (Recommended Plan): This alternative would have positive effects on benthic resources when combined with

other Federal, state, local, and private restoration efforts. Wetland restoration, nourishment, and reconnection ofhydrology of 1,602 acres would result in greater resources for benthic organisms due to the export of dissolved organiccompounds and detritus from the wetlands.ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres swamp habitat restored.ALT 35: Cumulative impacts similar to ALT 33 except 820 acres swamp habitat restored.ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres swamp habitat restored.ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres swamp habitat restoredALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres swamp habitat restored.ALT 39: Cumulative impacts similar to ALT 33 except 3,881 acres swamp habitat restored.

Fishery

Resources

US, LA, & SA: Reduction in fisheries habitat,increased catches, gear improvement, catchregulations, Magnuson-Stevens FisheryConservation and Management Act andamendments, Formation of NMFS and LDWF.About 90% of the world’s seafood resources havebeen depleted in the past century; 38% of thedepleted species have declined by more than 90%;7% of the species of fish studied by researchershave become extinct (Worm et al., 2006).SA: Construction of the ARDC and dredged

material berms prevent exchange of organisms andwater between the swamp and the ARDC.

US, LA, & SA: Continued institutional recognition,catch regulations, habitat loss decreasedsomewhat by coastal restoration efforts, andcontinued net habitat loss.LA & SA: Fishery populations in Louisiana areshifting towards more marine and higher salinitytolerant species as land loss and saltwater

intrusion into interior regions continues.SA: Fishery population changes associated with

conversion of swamp habitat to freshwater marshand open water habitat and as water qualitydeclines.

US, LA, & SA: Continued institutional recognition and catch

regulations. Continued loss of fishery resources unlessintensified efforts to protect them locally, statewide, andnationally.LA & SA: Populations in Louisiana would likely continue to

shift towards more saline-oriented species as land loss and

saltwater intrusion into interior regions continues.SA: Conversion of 18,204 acres of swamp vegetation to fresh

marsh and open water habitat increases availability of openwater habitat for fish and aquatic organisms. However,ARDC berms limit aquatic organism access; water qualitydeclines make environment suitable only for those aquaticorganisms tolerant of low DO conditions.

US & LA: Continued loss of fishery resources unless intensified efforts to protect them, locally, statewide, andnationally.ALT 33 (Recommended Plan): This alternative would have positive effects on fishery resources when combined with

other Federal, state, local, and private restoration efforts. This alternative would restore a net total of 1,602 acres ofbald cypress-tupelo swamp habitat. Swamp restoration and reconnected hydrology would result in greater resourcesfor aquatic and fishery resources due to the export of dissolved organic compounds and detritus from wetlands.ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres reconnected and restored.ALT 35: Cumulative impacts similar to ALT 33 except 820 acres reconnected and restored.ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres reconnected and restored.ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres reconnected and restored.ALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres reconnected and restored.

ALT 39: Cumulative impacts similar to ALT 33 except 3,881 acres reconnected and restored.

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Essential FishHabitat (EFH)

US and LA: General decrease in quality of EFHbeginning in the mid-1990s. Institutionalrecognition of decline in EFH quality; passage ofMagnuson-Stevens Fishery Conservation andManagement Act, as amended.SA: No EFH present.

US and LA: Continued institutional recognition;continued wetland loss and decline in quality ofEFH.SA: No EFH present.

US and LA: Continued institutional recognition; continued

wetland loss and decline in quality of EFH.SA: Continues to be no EFH present.

US and LA: Continued institutional recognition; continued wetland loss and decline in quality of EFH.ALT 33 (Recommended Plan): This alternative would have no effect on EFH. EFH not likely to develop.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Threatened andEndangeredSpecies

US, LA & SA: Institutional recognition of

importance of wetlands decline in listed species viathe Endangered Species Act (ESA). Decrease insome animal and plant populations and theircritical habitat including loss of wetlands.

US, LA, & SA: Continued institutional recognition

of decline in listed species; continued loss ofwetlands that are critical habitat to many listedspecies.SA: Degradation and loss of important fish and

wildlife habitats for shelter, nesting, feeding,roosting, cover, nursery, and other liferequirements.

US, LA, & SA: Continued institutional recognition of decline

in listed species; continued loss of wetlands.SA: Conversion of 18,204 acres of swamp habitat to

fragmented and degraded fresh marsh and open waterhabitats; any listed species that may be presently utilizingthe habitats would likely not be impacted.

US and LA: Continued institutional recognition of decline in listed species; continued loss of wetlands.

ALT 33 (Recommended Plan): This alternative would have positive effects on threatened and endangered resources

when combined with other Federal, state, local, and private restoration efforts. This alternative would restore a nettotal of 1,602 acres of swamp habitat that would be available for use by listed and other species.ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres of habitat restored.ALT 35: Cumulative impacts similar to ALT 33 except 820 acres of habitat restored.

ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres of habitat restored.ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres of habitat restored.ALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres of habitat restored.ALT 39: Cumulative impacts similar to ALT 33 except 3,881 acres of habitat restored.

Cultural andHistoricResources

US, LA, & SA: Institutional recognition via theNational Historic Preservation Act (and others).Historic and cultural resources subjected to naturalprocesses and man-made actions.

US, LA, & SA: Continued institutional recognition.

Human activities as well as natural processes canpotentially destroy historic and natural resources.The loss of land threatens the existence andintegrity of these resources.

US, LA, & SA: Continued institutional recognition. Potential

loss of resources due to natural and human causes.SA: The loss of land within the SA threatens the existence

and integrity of these resources.

US & LA: Potential loss of resources due to natural and human causes.ALT 33 (Recommended Plan): All types of stabilization would prevent further land loss and erosion. This alternativewould benefit cultural and historical resources in the long term by slowing or stopping land loss and erosion thatthreatens their existence. No archaeological sites were located at the proposed cuts, however one modern Rangiacuneata scatter was observed near the easternmost cut. The old railroad grade and the ARDC are recommended as noteligible for NHRP listing.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Aesthetics

US, LA, & SA: Technical recognition via 1988

USACE Visual Resources Assessment Procedure.Institutional recognition via Wild and Scenic RiversAct, Louisiana Scenic Rivers Act, Scenic Bywaysand others.LA & SA: Aesthetic resources negatively impactedby hurricanes Katrina, Rita, Gustav, and Ike. BlindRiver is a designated Scenic River.

US, LA, & SA: Continued institutional recognition.Visual resources have been destroyed, enhanced,or preserved by human activities and naturalprocesses.LA & SA: Continued wetland loss may have anadverse effect on the visual complexity of thebayous and swamps.

US, LA, & SA: Continued institutional recognition.Continued human population growth and development andother human activities have the potential to destroy, enhanceor preserve visual resources.SA: Erosion and land loss could result in the loss of

vegetation that may provide a visually complex environmentand desirable views and reduce opportunities for viewing

wildlife.

US & LA: Continued human population growth and development and other human activities have the potential todestroy, enhance or preserve visual resources.ALT 33 (Recommended Plan): This alternative would have positive effects on aesthetics when combined with other

Federal, state, local, and private restoration efforts. Maintaining visually appealing resources systems would supporttourism on Louisiana’s Scenic Byways and remote areas of visual interest. Restoration features would provide a morecontiguous swamp, which would increase and protect desirable viewscapes.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Recreational

US, LA, & SA: Recreational resources not an issue.Institutional recognition via Federal Water ProjectRecreation Act, Land and Water Conservation Act,and National Wildlife Refuge System Acts.SA: Recreation activities in SA centered on natural

resources. A portion of Maurepas Swamp WMA is

present.

US & LA: Continued institutional recognition.Increased recreational activities impact nationaland state wetlands.SA: Recreation activities centered on natural

resources. Continued conversion of marsh andswamp to open water resulting in decreasing

recreational opportunities.

US, LA, & SA: Continued institutional recognition. Potential

loss of recreational resource base due to continued swampand freshwater marsh degradation and loss.

US & LA: Continued loss of recreational resource base due to continuing coastal and wetland degradation and loss.ALT 33 (Recommended Plan): This alternative would have positive effects on recreational resources when combined

with other Federal, state, local, and private restoration efforts. It would support and sustain a greater number ofwetland-dependent recreational activities, provide for a more stable localized recreational economy, and possibly

increase local recreation-related employment and income.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –Population andHousing

US: Population increasing in some areas,decreasing in other areas.LA: Hurricanes Katrina and Rita adversely affected

populations throughout the state.SA: Development along the ARDC, Amite and

Blind Rivers and on ridges. Populations withinAscension and Livingston Parishes increasing.

US: Increasing population (7.2%) from 2000-2007;

with over 300 million people.LA: Slight decrease

(-3.9%) in population from 2000-2007.SA: Development along the ARDC, Amite and

Blind Rivers and on ridges. Populations withinAscension and Livingston Parishes have beenincreasing.

US & LA: Increasing populations worldwide.SA: There may be further construction and an increase in the

population. Populations within Ascension and Livingston

Parishes projected to increase further. Study areapopulations would be adversely impacted by continuedhabitat degradation and conversion.

US & LA: Increasing populations worldwide. Populations within Ascension and Livingston Parishes are projected to

increase further.ALT 33 (Recommended Plan): This alternative would have no cumulative impacts on populations.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources–Employmentand Income

US: Increased habitation, employment andtourism.LA: Slight increase in employment in Louisiana.

Hurricanes Katrina and Rita had an adverse effecton employment and personal income. Rebuildingefforts provide some new job opportunities.SA: Development along the ARDC, Amite andBlind Rivers and on ridges. Total employment inAscension and Livingston Parishes increasing.

US & LA: Increasing population growth andemployment and personal income opportunities.

Economic activity related to wetland resourceswould be adversely affected by the depletion ofthese resources.

SA: Development along the ARDC, Amite andBlind Rivers and on ridges. Employment andincome resources are primarily retail, eating and

drinking establishments. Total employment in

Ascension and Livingston Parishes increasing.

US & LA: Increasing population growth and employment and

personal income opportunities. Economic activity related towetland resources would be adversely affected by thedepletion of these resources.SA: Development along the ARDC, Amite and Blind Rivers

and on ridges. Total employment in Ascension and LivingstonParishes expected to increase.

US & LA: Increasing human populations lead to competition for employment and income. Economic activity related to

wetland resources would be adversely affected by the depletion of these resources.

ALT 33 (Recommended Plan): This alternative would have positive effects on employment and income when combinedwith other Federal, state, local, and private restoration efforts. Cumulative impacts of the proposed action are relatedto the increased stability of the wetland resources throughout the region. Local wetland-dependent jobs, such as

recreation and commercial fisheries, would likely be positively impacted.

ALTS 34-39: Cumulative impacts would be similar to ALT 33.

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Socioeconomicand HumanResources–CommunityCohesion

US, LA, & SA: Community cohesion is affected byinfrastructure development and communitydevelopment.LA: Hurricanes Katrina and Rita adversely affected

community cohesion in southern portions of thestate.

SA: The SA is populated along the ARDC, Amiteand Blind Rivers, and on ridges.

US, LA, & SA: Community cohesion is affected byinfrastructure development and communitydevelopment.LA: Hurricanes Katrina and Rita adversely

affected community cohesion in southern portionsof the state.

SA: The SA is populated along the ARDC, Amiteand Blind Rivers, and on ridges.

US, LA, & SA: Community cohesion would continue to beaffected by infrastructure development and communitydevelopment.SA: Several of the current subdivisions would expand. A

proposed bridge over the ARDC would increase communitycohesion.

US & LA: Increasing populations worldwide. Increasing opportunity for infrastructure development and communitycohesion development.ALT 33 (Recommended Plan): There would be no cumulative impacts on community cohesion.

ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –EnvironmentalJustice

US: Institutional recognition via Executive Order12898.LA: Hurricanes Katrina and Rita adversely affected

Environmental Justice resources in the state.SA: Population in the vicinity of Head of Island has

30-40% minority composition; poverty levels lowwithin study area.

US & LA: Continued institutional recognition;increasing Environmental Justice resources as aresult of increase in population and decrease in

economic output from 2000-2009.SA: Environmental Justice resources within study

area appear stable.

US & LA: Continued institutional recognition; potential

increase in Environmental Justice resources as a result ofcontinued economic recession.SA: There may be further construction and an increase in the

population. Environmental Justice resources may increase;these resources would likely remain unchanged.

US & LA: Increasing populations worldwide. Increasing opportunity for the development of minority communities andthe expansion of low-income populations worldwide.ALT 33 (Recommended Plan): There would be no cumulative impacts on environmental justice. There is no

opportunity for the development of minority communities or the expansion of low-income populations as the areasimpacted by this alternative are not populated. Environmental justice issues are unlikely to occur when combinedwith other Federal, state, local, and private restoration efforts.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –Infrastructure

US & LA: Increasing population growth and

supporting infrastructure in the form of roads,bridges, pipelines, homes, businesses, anddecreases in coastal and other wetlands.LA & SA: Extensive damages to infrastructure dueto Hurricanes Katrina and Rita which is still beingrepaired. State and local roads, railroad grade,overhead distribution lines, and undergroundtelephone lines traverse the study area.

US: Increasing population growth and supporting

infrastructure contributes to degradation and lossof coastal and other wetlands, which contributes toincreased maintenance costs of infrastructure.LA & SA: State and local roads, relict railroadgrade, overhead distribution lines, andunderground telephone lines traverse the studyarea.

US & LA: Continued population growth and supportinginfrastructure contributes to degradation and loss of coastaland other wetlands. Degradation and loss of wetlands wouldcontribute to increased maintenance costs of infrastructure.SA: Wetland land loss potentially threatens infrastructure

passing through area and would result in increasedmaintenance. Several of the current subdivisions wouldexpand, creating additional roads, bridges, and associatedutilities.

US & LA: Continued population growth and supporting infrastructure contributes to degradation and loss of coastaland other wetlands. Degradation and loss of wetlands contribute to increased maintenance costs of infrastructure.ALT 33 (Recommended Plan): This alternative would have positive effects on infrastructure when combined withother Federal, state, local, and private restoration efforts. There would be a reduced level of infrastructure damagesand relocations compared to the No-Action Alternative.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources–Business andIndustry

US & LA: Increasing population growth and

supporting infrastructure in the form of roads,bridges, pipelines, homes, and businesses.LA & SA: Extensive damages to businesses andindustry due to Hurricanes Katrina and Rita whichis still being repaired.SA: Businesses are generally retail stores and

restaurants.

US & LA: Increasing population growth and

supporting businesses and industry developmentcontributes to degradation and loss of coastal andother wetlands.SA: Businesses are generally retail stores and

restaurants.

US & LA: Continued population growth and supporting

business and industry development contributes todegradation and loss of coastal and other wetlands.Degradation and loss of wetlands would contribute topotential losses of businesses.SA: Wetland land loss would potentially threaten businessesin the study area.

US & LA: Continued population growth and supporting business and industry development contributes to degradation

and loss of coastal and other wetlands, which contributes to potential loss of businesses.ALT 33 (Recommended Plan): This alternative would have little effects on business and industry when combined with

other Federal, state, local, and private restoration efforts. The study area does not appear to provide manyopportunities for future business growth.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources–Traffic andTransportation

US & LA: Increasing population growth increases

traffic and transportation issues.

SA: State and local roads traverse the study area.

Traffic is generally confined to residents andrecreational visitors.

US & LA: Increasing population growth increases

traffic and transportation issues.

SA: State and local roads traverse the study area.

Traffic is generally confined to residents andrecreational visitors.

US & LA: Continued population growth increases traffic and

transportation issues

SA: Wetland land loss potentially threatens roads passing

through area and results in increased maintenance. Severalof the current subdivisions would expand, creating additionalroads, bridges, and traffic.

US & LA: Continued population growth increases traffic and transportation issues.ALT 33 (Recommended Plan): This alternative would have little effect on traffic and transportation when combined

with other Federal, state, local, and private restoration efforts. There would be a reduced level of road damages andrelocations compared to the No-Action Alternative.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Socioeconomicand HumanResources–Public Facilitiesand Services

US & LA: Increasing population growth increases

public facilities and services issues.SA: Public facilities and services generally serve

residents and recreational visitors.

US & LA: Increasing population growth increases

public facilities and services issues.SA: Public facilities and services generally serve

residents and recreational visitors.

US & LA: Increasing population growth increases public

facilities and services issues.SA: Wetland land loss potentially threatens public facilitiesand services and increases maintenance. Several of thecurrent subdivisions would expand, creating additional needsfor public facilities and services.

US & LA: Continued population growth increases public facilities and services issues.ALT 33 (Recommended Plan): This alternative would have little effect on public facilities and services when combinedwith other Federal, state, local, and private restoration efforts. There would be a reduced level of public facilities andservices damages and relocations compared to the No-Action Alternative.

ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources–LocalGovernmentFinances

US & LA & SA: Increasing population growth

increased local government finances.

US & LA & SA: Increasing population growth

increases local government finances.

US & LA: Increasing population growth would increase local

government finances.

SA: There is no potential for new town development, and

none would be developed in the future. Expansion of thecurrent subdivisions would increase the tax base, thusincreasing local government finances.

US & LA: Continued population growth increases local government finances.

ALT 33 (Recommended Plan): This alternative would have little effect on local government finances when combinedwith other Federal, state, local, and private restoration efforts. There is no potential for new town development withinor contiguous to the area impacted by this alternative, and none would be developed in the future. Expansion of thecurrent subdivisions would increase the tax base, thus increasing local government finances. ALTS 34-39: Cumulative

impacts would be similar to ALT 33.

Socioeconomicand HumanResources–

Tax Revenue andProperty Values

US & LA & SA: Increasing population growth

increases tax revenue and property values.

US & LA & SA: Increasing population growth

increases tax revenue and property values.

US & LA: Increasing population growth increases tax

revenue and property values.SA: Additional increases in property values and tax revenueswould be sustained through the filling of lots in the existingand proposed subdivisions. At the same time, property valuesmay drop from lowering aesthetics due to swampdegradation.

US & LA: Continued population growth increases tax revenue and property values.

ALT 33 (Recommended Plan): This alternative would have little effect on tax revenue and property values when

combined with other Federal, state, local, and private restoration efforts. Additional increases in property values andtax revenues would be sustained through the filling of lots in the existing and proposed subdivisions as well as due toincreased aesthetics.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources–Community andRegional Growth

US & LA & SA: Increasing population growth

increases community and regional growth.

US & LA & SA: Increasing population growth

increases community and regional growth.

US & LA: Increasing population growth increases community

and regional growth.

SA: Additional increases in community and regional growth

would be sustained through the filling of lots in the existingand proposed subdivisions.

US & LA: Continued population growth increases community and regional growth.

ALT 33 (Recommended Plan): This alternative would have little effect on community and regional growth when

combined with other Federal, state, local, and private restoration efforts. Additional increases in community andregional growth would be sustained through the filling of lots in the existing and proposed subdivisions.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Socioeconomicand HumanResources –Land UseSocioeconomicsAgriculture

US & LA: Agriculture is important to the economyof the US and coastal Louisiana.LA: Important crops include sugar cane, rice, and

soybeans.SA: Approximately 373 acres of agricultural lands,

primarily livestock pastures are present.

US & LA: Agriculture is important to the economyof the US and coastal Louisiana.LA: Important crops include sugar cane, rice, and

soybeans.SA: Approximately 373 acres of agricultural lands,

primarily livestock pastures are present.

US & LA: Agriculture would continue to be important to theeconomy of the US and coastal Louisiana.SA: Agricultural lands, primarily livestock pastures, within

the study area would continue to be used and may beadversely impacted by habitat conversion and land loss.

US & LA: Continued importance of agriculture to the economy of the US and coastal Louisiana. Agricultural landsmay be adversely impacted by habitat conversion and land loss.

ALT 33 (Recommended Plan): This alternative would have positive effects on agriculture when combined with other

Federal, state, local, and private restoration efforts. There would be a reduced level of agriculture land habitatconversion and land loss compared to the No-Action Alternative.

ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –Land UseSocioeconomicsForestry

US & LA: Timber production is important to the

economy of the US and Louisiana.LA: Timber has historically been important to theeconomy of Ascension and Livingston Parishes.SA: Timber was harvested extensively before 1940.

US & LA: Timber production is important to theeconomy of the US and Louisiana.LA: Timber continues to be important to theeconomy of Ascension and Livingston Parishes.SA: Increased interest in harvesting within thestudy area in recent years, but little harvesting iscurrently taking place.

US & LA: Timber production would continue to be importantto the economy of the US and Louisiana.LA: Timber would continue to be important to the economy ofAscension and Livingston Parishes.SA: Little harvesting would likely take place in the futuredue to the lack of quality timber.

US & LA: Continued importance of timber production to the economy of the US and Louisiana. Timber lands may beadversely impacted by habitat conversion and land loss.

ALT 33 (Recommended Plan): Channel Improvement, Flowage and Deposition, and Wetland Creation andRestoration easements would be placed within the primary and secondary areas of impact for Alternative 33 ,effectively restricting timber harvesting within portions of the study area over an indefinite period of time. Thereforethis alternative would have negative impacts on timber harvesting within portions of the study area. The Real EstatePlan in Appendix J provides descriptions of the easements which will be placed within the areas of impact.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –Land UseSocioeconomicsPublic Lands

US & LA: Public lands are important to the

economy of the US and Louisiana.SA: A portion of the Maurepas WMA is the only

public lands present.

US & LA: Public lands are important to theeconomy of the US and Louisiana.SA: A portion of the Maurepas WMA is the only

public lands present.

US & LA: Public lands would continue to be important to theeconomy of the US and Louisiana.SA: A portion of the Maurepas WMA is the only public lands

present. These lands may be adversely affected by future sealevel rise and continued habitat conversion and land loss.

US & LA: Continued importance of public lands to the economy of the US and Louisiana. Public lands may beadversely impacted by habitat conversion and land loss.ALT 33 (Recommended Plan): This alternative would have positive effects on public lands when combined with other

Federal, state, local, and private restoration efforts. There would be a reduced level of public land habitat conversionand land loss compared to the No-Action Alternative. At the same time, public lands may be adversely impacted byfuture sea level rise.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –Navigation

US, LA & SA: Navigation interests have

historically been a critical factor to national, state,and local interests. Growth of port facilities andinland waterways and traffic. Hurricanes Katrinaand Rita impacted navigation infrastructure andinvestments. Public and private reinvestment torebuild navigation, port facilities, and inlandwaterways.SA: One Federal navigation channel (Amite River

and Bayou Manchac) and one Federal flood controlchannel (AR&T) are present. No major port orterminal installations are present.

US, LA & SA: Continued investment in portfacilities and inland waterways. Navigationcontinues to be important part of the nationaltransportation and commerce activities.SA: Amite River and Bayou Manchac Federalnavigation channel and AR&T flood controlchannel are primarily used for recreationalnavigation.

US & LA: Continued investment in port facilities and inlandwaterways. Navigation continues to be important part of the

national transportation and commerce activities.SA: Amite River and Bayou Manchac Federal navigationchannel and AR&T flood control channel are likely tocontinue to be used primarily for recreational navigation.

US & LA: Continued investment in port facilities and inland waterways. Navigation continues to be important part ofthe national transportation and commerce activities.ALT 33 (Recommended Plan): This alternative would have positive effects on navigation when combined with otherFederal, state, local, and private restoration efforts. Cumulative impacts would be the protection of navigationchannels.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

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Table 5.1. Comparison of Cumulative Impacts*

Significant

Resource

Past Actions

(Historic Conditions)

Present Actions

(Existing Conditions)

The No-Action Alternative (Future Without Project

condition)

Cumulative Impacts

(Comparison of Future With Proposed Action Impacts)

Socioeconomicand HumanResources –Man-MadeResourcesOil, Gas,Utilities, andPipelines

US, LA, & SA: Development of extensive networkof oil and gas pipelines in mid-1900s.

SA: Western Maurepas swamp experiences

significant oil and gas exploration, primarilysouthwest of study area.

US, LA, & SA: Increasing O&M costs as well asincreasing investment for oil and gas productionfacilities and pipelines, due to widespread coastalwetland loss.SA: Thirteen wells identified, plugged or

abandoned or no oil produced; two inactive wellbores and one active well bore; one active crude oilpipeline across northeastern corner.

US, LA, & SA: Increasing O&M costs as well as increasinginvestment in oil and gas production facilities and pipelines,increasing vulnerability of pipelines and other infrastructuredue to widespread coastal wetland loss.SA: Wells likely to remain and active pipelines likely to be

present.

US & LA: Continued investment in oil, gas, utilities, and pipelines.ALT 33 (Recommended Plan): This alternative would have positive effects on the protection of oil, gas, utilities, and

pipelines when combined with other Federal, state, local, and private restoration efforts. These facilities would be lesssusceptible to storm surges and other damage due to wetland loss.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –Man-MadeResourcesFlood Controland HurricaneProtection

US & LA: Flood of 1927 initiated nationalconstruction of hurricane and flood control levees,pump stations, and control structures. HurricanesKatrina and Rita caused significant widespreaddamages to existing hurricane and flood controlstructures.SA: The AR&T flood control project was completed

in 1964. Municipal and parish flood controlmeasures, including drainage canals and controlstructures are present.

US & LA: Largest national restoration effort ofhurricane and flood control in nation’s history.SA: The AR&T Federal flood control project is

present. Municipal and parish flood controlmeasures including drainage canals and controlstructures are present.

US & LA: As populations continue to migrate to coastal

communities, increasing investment in hurricane and floodcontrol levees, pump stations, and other flood controlfacilities would be needed.SA: Continued degradation of wetlands would result in

increases localized storm surge and storm wave damages.

US & LA: Continued loss of flood control and hurricane protection due to continued coastal and wetland degradationand loss.ALT 33 (Recommended Plan): This alternative would have positive effects on flood control and hurricane protection

when combined with other Federal, state, local, and private restoration efforts. The proposed action would nourish andcreate swamp that is currently converting to open water, leaving adjacent areas more vulnerable to storm surges.Cumulative impacts include some protection of the ARDC and surrounding developments from storm damages.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

Socioeconomicand HumanResources –

NaturalResourcesCommercialFisheries

US, LA, & SA: Institutional recognition, formation

of NMFS and LDWF; Magnuson-Stevens FisheryConservation and Management Act andamendments. Reduction in fisheries habitat,increased commercial catches, gear improvement,catch regulations. Commercial landings in the USin 2007 were nearly 4.2 million metric tons. Of the528 individual stocks, 45 (24%) are overfished and41 (17%) are subject to overfishing (NOAA).LA: Commercially important species, including

brown and white shrimp, blue crabs, easternoysters, and menhaden abundant.

SA: Study area may provide some habitat for gulf

menhaden and striped mullet but no commercial

fishery for these species is present.

US, LA & SA: Continued institutional recognition

and regulation of commercial fisheries.LA: Largest producer of shrimp, menhaden, bluecrabs, and eastern oysters.SA: Study area may provide some habitat for gulf

menhaden and striped mullet, but commercialfishery for these species is not present.

US: Institutional recognition continues; commercial fisheriesdecline expected as overfishing and habitat degradation andloss continues unless concerted efforts to protect, restore, andregulate a sustainable industry.LA & SA: Loss of commercial fishery habitat due to loss of

essential wetland habitats and salinity changes.

US & LA: Institutional recognition continues; commercial fisheries decline expected as overfishing and habitatdegradation and loss continues unless concerted efforts to protect, restore, and regulate a sustainable industry.

ALT 33 (Recommended Plan): This alternative would have positive effects on commercial fisheries when combined

with other Federal, state, local, and private restoration efforts. A net total of 1,602 acres of swamp habitat would berestored and nourished. Localized improvements of fishery habitats would provide some undetermined positivebenefits to local commercial fisheries.ALT 34: Cumulative impacts similar to ALT 33 except 1,459 acres swamp habitat restored and nourished.ALT 35: Cumulative impacts similar to ALT 33 except 820 acres swamp habitat restored and nourished.ALT 36: Cumulative impacts similar to ALT 33 except 3,061 acres swamp habitat restored and nourished.ALT 37: Cumulative impacts similar to ALT 33 except 2,279 acres swamp habitat restored and nourished.ALT 38: Cumulative impacts similar to ALT 33 except 2,422 acres swamp habitat restored and nourished.ALT 39: Cumulative impacts similar to ALT 33 except 3,881 acres swamp habitat restored and nourished.

Hazardous, Toxic,and RadioactiveWaste

US, LA, & SA: Institutional recognition under ER1165-2-132. Establishment of the USEPA and

LDEQ agencies.SA: Few potential HTRW sites are located near or

within the study area.

US, LA, & SA: Continued institutional recognition.

Increasing human populations andindustrialization results in increased potential forHTRW problems.SA: Few potential HTRW sites are located near orwithin the study area.

US, LA, & SA: Continued institutional recognition.Increasing human populations and industrialization result inincreased potential for HTRW problems.

US & LA: Increasing human populations worldwide. Increasing opportunity for HTRW problems.

ALT 33 (Recommended Plan): There would be no cumulative impacts on HTRW. HTRW issues are unlikely to occur

when combined with other Federal, state, local, and private restoration efforts.ALTS 34-39: Cumulative impacts would be similar to ALT 33.

*Includes Spatial/Geographic Extent (Continental United States [US], Louisiana [LA], and Study Area [SA], and Temporal(Past, Present, and Future with the No-Action Alternative). This cumulative impact analysis follows the 11-step process described in the 1997 report by

the Council on Environmental Quality entitled “Considering Cumulative Effect Under the National Environmental Policy Act”.

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22 

Lake Maurepas

Lake

Pontchartrain

Mississippi

River

Mississippi River

Ami te Rive r

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: July 2010Scale:

Source: NAIP/GEC

RELATED PROJECTS IN VICINITY OF

AMITE RIVER DIVERSION CANAL MODIFICATION Figure: 5.1

1:220,000

Map ID: 27850108-1381

Texas Mississippi

Arkansas

Legend

LCA Amite River Diversion Canal Study AreaCIAP Hydrologic Restoration in Swamps West of Lake MaurepasLCA Small Diversion at Convent/Blind RIverLCA Small Diversion at Hope CanalMaurepas Swamp Wildlife Management Area

±01234

Miles Image: 2007 Ascension, Livingston, St. James, St. John, and Tangipahoa Parishes USDA-FSA-APFO NAIP MrSID Mosaic

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Table 5.2. Net Acres1 Created, Restored, and/or

Protected by Other Federal, State, Local, and

Private Restoration Efforts (LCA, 2004)

Program Net Acres Created (LCA Subprovince 1)

Breaux Act CWPPRA 33,690 1

State 2,543

PCWRP 14 2

Mitigation Civil Works Projects 4,990 3

Mitigation Regulatory Permits 6,411

Vegetation 535 4

Section 204/1135, Beneficial Use 226

WRDA 16,000 5

Other 0 6

TOTALS 64,410

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 U.S. Fish and Wildlife Service (USFWS); unable to determine exact

locations.

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.

dissolved solids and turbidity, as well as potentially increase total metals and

nutrients as they are released from the sediments. These impacts would be

temporary and localized, lasting until the soils become compacted and vegetation is

re-established. In addition, Best Management Practices (BMPs) would be used to

minimize the amount of sediment entering the water, both during and after

construction, until dredged material berms are vegetated.

Indirect. Indirectly, this alternative would improve hydrologic connectivity

to a net total of 1,602 acres of wetland soils located between the ARDC and the

adjacent swamp. Improved hydrologic connectivity would also allow nutrients and

sediments to be introduced from the ARDC into the swamp during flood events and

from runoff during localized rainfall events. Nutrients and sediment delivered to

the swamp would improve biological productivity and reduce the chances of further

habitat deterioration. Finally, the establishment of hydrologic connectivity would

reduce the likelihood of the swamp being converted to marsh or open water.

Cumulative. Alternative 33 would work additively with other projects

within the general area to benefit soil resources including a net total of 1,602 acres

of wetland soils would be hydrologically restored and nourished. The impacts to

wetland soils within the study area and vicinity would be additive to some extent

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with other Federal, state, local, and private restoration efforts across coastal

Louisiana (see Figure 5.1 and Table 5.2).

5.1.1.3 Alternative 34

Direct. Direct impacts of this alternative would be similar to Alternative 33

(Recommended Plan), except approximately 3.4 acres of soil from the existing

dredged material berm would be excavated and approximately 10.5 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except 1,459 acres of swamp would be benefited.

Cumulative. Cumulative impacts of implementing this alternative would be

similar to those described for Alternative 33 (Recommended Plan).

5.1.1.4 Alternative 35

Direct. Direct impacts of this alternative would be similar to Alternative 33

(Recommended Plan), except approximately 2.4 acres of soil from the existing

dredged material berm would be excavated and approximately 7.2 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except 820 acres of swamp would be benefited.

Cumulative. Cumulative impacts of implementing this alternative would be

similar to those described for Alternative 33 (Recommended Plan).

5.1.1.5 Alternative 36

Direct. Direct impacts of this alternative would be similar to Alternative 33

(Recommended Plan), except approximately 6.0 acres of soil from the existing

dredged material berm would be excavated and approximately 29.1 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except 3,061 acres of swamp would be benefited.

Cumulative. Cumulative impacts of implementing this alternative would be

similar to those described for Alternative 33 (Recommended Plan).

5.1.1.6 Alternative 37

Direct. Direct impacts of this alternative would be similar to Alternative 33

(Recommended Plan), except approximately 5.8 acres of soil from the existing

dredged material berm would be excavated and approximately 17.7 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except 2,279 acres of swamp would be benefited.

Cumulative. Cumulative impacts of implementing this alternative would be

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similar to those described for Alternative 33 (Recommended Plan).

5.1.1.7 Alternative 38

Direct. Direct impacts of this alternative would be similar to Alternative 33

(Recommended Plan), except approximately 5.0 acres of soil from the existing

dredged material berm would be excavated and approximately 25.8 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except 2,422 acres of swamp would be benefited.

Cumulative. Cumulative impacts of implementing this alternative would be

similar to those described for Alternative 33 (Recommended Plan).

5.1.1.8 Alternative 39

Direct. Direct impacts of this alternative would be similar to Alternative 33

(Recommended Plan), except approximately 8.4 acres of soil from the existing

dredged material berm would be excavated and approximately 44.0 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except 3,881 acres of swamp would be benefited.

Cumulative. Cumulative impacts of implementing this alternative would be

similar to those described for Alternative 33 (Recommended Plan).

5.1.2 Waterbottoms

5.1.2.1 No-Action Alternative

Direct. There would be no direct impacts to waterbottoms.

Indirect. Existing swamp habitat would continue to be converted to water

bottoms. The decomposition of swamp vegetation would initially increase the

availability of nutrients and detritus. However, the continued degradation from

fresh marsh to shallow open water would ultimately decrease available nutrients

and detritus.

Cumulative. Throughout coastal Louisiana, and within the study area, an

increase in shallow water bottom acreage would occur in response to wetland loss.

Overall cumulative impacts include the conversion of 18,204 acres of swamp to a

shallow open water system (Figure 2.2), which would be additive with other swamp

losses and degradation impacts to waterbottoms throughout the region, state, and

nation. However, the impacts to waterbottoms in the study area and vicinity would

be offset to some extent by other Federal, state, local, and private restoration efforts

across coastal Louisiana (see Figure 5.1 and Table 5.2).

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5.1.2.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts to waterbottoms would generally be associated with

construction activities including dredging and placement of borrow material. A very

small amount of waterbottom in the ARDC adjacent to the dredged material berm

would also be excavated during the conveyance channel construction. Construction

of the conveyance channels would create 18.6 acres of waterbottoms.

Indirect. Indirect impacts to waterbottoms would be related primarily to

construction activities primarily associated with dredging and placement of dredged

material for creation of BLH "islands". Construction of conveyance channels would

decrease swamp habitat degradation, benefiting waterbottoms by providing

increased dissolved organic compounds and detritus. Restoring hydrologic

connectivity would contribute to re-establishing a wet-dry cycle to existing swamp

waterbottoms, thereby increasing swamp vegetation productivity and health. In

addition, dissolved organic compounds and detritus from the restored swamp

vegetation would also increase the health and productivity of the swamp. A net

total of 1,602 acres of swamp habitat and associated water bottoms would be

benefitted by this alternative.

Cumulative. Throughout Coastal Louisiana, an increase in shallow water

bottom acreage would occur in response to wetland loss. Implementation of

Alternative 33 (Recommended Plan) would decrease the amount of waterbottoms

created from the deterioration and conversion of existing swamp habitat to shallow

open water habitat. The impacts to waterbottoms within the study area and

vicinity would be additive to some extent with other Federal, state, local, and

private restoration efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.1.2.3 Alternative 34

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 10.5 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except approximately 1,459 acres of swamp

habitat would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.1.2.4 Alternative 35

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 7.2 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except approximately 820 acres of swamp

habitat would be benefited.

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Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.1.2.5 Alternative 36

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 29.1 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except approximately 3,061 acres of swamp

habitat would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.1.2.6 Alternative 37

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 17.7 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except approximately 2,279 acres of swamp

habitat would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.1.2.7 Alternative 38

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 25.8 acres of

conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except approximately 2,422 acres of swamp

habitat would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.1.2.8 Alternative 39

Direct. Direct impacts of this alternative would be similar to those

described for Alternative 33 (Recommended Plan), except approximately 36.3 acres

of conveyance channel habitat would be created.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except approximately 3,881 acres of swamp

habitat would be benefited.

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Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.2 HYDROLOGY

Hydrologic change is the main measure by which the swamps can be restored in the

study area. Hydrologic restoration must account for the Relative Sea Level Rise

(RSLR). Given the hydrologic influence of tidal Lake Maurepas and the regional

subsidence conditions, RSLR could affect the computed flows in the proposed

conveyance channels and the stage durations. In response to this concern, the

Project Delivery Team (PDT) evaluated the potential impact of RSLR on the

TSP/Recommended Plan. The evaluation adhered to guidelines established in

Incorporating Sea Level Change Considerations in Civil Works Programs, EC 1165-

2-211 (USACE, 2009a).

EC 1165-2-211 provides USACE 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

and systems of projects. Recent climate research by the Intergovernmental Panel on

Climate Change predicts continued or accelerated global warming for the 21st

Century and possibly beyond, which will cause a continued or accelerated rise in

global mean sea-level. Impacts to coastal and estuarine zones caused by sea-level

change must be considered in all phases of Civil Works programs.

In the preparation of the EC, USACE has relied entirely on climate change science

performed and published by agencies and entities external to USACE. The EC

documents this science and provides information on how to calculate three proposed

sea level rise scenarios for use in projects.

The USACE guidance requires an assessment of project performance based on three

estimates (low, intermediate, and high) of predicted relative sea level rise (RSLR).

The low estimate reflects the local historic rate for the study area, based on longterm local gage data. The intermediate and high estimates reflect a combination of

the local historic subsidence rate with either the modified NRC Curve I or the NRC

Curve III estimate of eustatic sea level rise. The USACE New Orleans District

prepared RSLR estimates in accordance with EC 1165-2-211 for LCA projects Amite

River Diversion Canal and Small Diversion at Convent/Blind River (USACE,

2009b). The study areas for both projects are hydrologically independent; therefore

any proposed actions would not result in ecosystem benefits or impacts between the

two projects. The following estimates of RSLR account for both the eustatic rate of

sea level rise and the local subsidence rate.

Low Rate RSLR - Consistent with guidance provided in EC1165-2-211, the

USACE gauge at the West End in Lake Pontchartrain was used to calculate a

representative historic rate for the project area. Daily stage data from 1959 to 2009

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indicate a rate of 9.20 mm/yr (0.0302 ft/yr; see Figure 5.2) with a standard error of

the linear trend line of 0.65 foot. Using the rate of 9.20 mm/yr, a starting year of

2012, and a 50-year period of analysis, the USACE projects a sea level rise of 1.5

feet for 2062. The rate of 9.20 mm/yr includes both the eustatic sea level rise and

the local subsidence contributions to the estimated total RSLR.

Intermediate and High Rates - To estimate the local subsidence rate for

the project area, the USACE subtracted the global eustatic rate (1.7 mm/yr) from

the local sea level rate or

Local subsidence rate = 9.20 mm/yr – 1.7 mm/yr = 7.50 mm/yr.

The following formula yields an estimate of the total rise in eustatic sea level

for the project life for the intermediate and high rate cases of sea level rise:

)()(0017.0)()(

2

1

2

2 1 12 2 tEtE =− −+− ttbtt

where: b=the acceleration factor for each curve, or 2.36E-5 and 1.005E-4,

respectively, t1=the time in years between the project’s construction date and 1986,

and t2=the time between a future date at which one wants an estimate for sea level

rise and 1986.

These eustatic estimates, when added to the local subsidence estimate, yield

the total sea level rise for the intermediate and high rate cases. Table 5.3 presents

a summary of the estimated total sea level rise in five-year increments through the

50-year period of analysis for each case. Figure 5.2 shows the estimated sea level

rise for each case.

Table 5.3. Summary of Five-year Sea Level Rise for Each Case

(USACE, 2009, Estimated Sea level Rise for Amite River Diversion

and Convent/Blind River Diversion LCA Projects)

Project year Low Rate

(feet)

Intermediate Rate

(feet)

High Rate

(feet)

2012 0.0 0.0 0.0

2017 0.2 0.2 0.2

2022 0.3 0.3 0.5

2027 0.5 0.5 0.8

2032 0.6 0.7 1.1

2037 0.8 0.9 1.4

2042 0.9 1.1 1.7

2047 1.1 1.3 2.0

2052 1.2 1.5 2.4

2057 1.4 1.7 2.8

2062 1.5 1.9 3.2

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Figure 5.2. Plot of Sea Level Rise for Each Case

(USACE, 2009, Estimated Sea level Rise for Amite River Diversion)

Impact of RSLR - The HEC-RAS models for the No-Action Alternative and

the With Project Alternative for 2062 (Year-50) were rerun for the three RSLR cases

by adding 1.5, 1.9, and 3.2 feet to the Amite River at the Maurepas hydrograph

downstream boundary condition. Model results are presented in Tables 5.4, 5.5, and

5.6. The previous results (Year 1) for computed flows in the exchange channels

versus computed Year 50 flows for low, intermediate, and high RSLR are included

in Table 5.4. Similar comparisons of stage durations for the previously computed

Year 1 versus Year 50 low, intermediate, and high RSLR for the No-Action

Alternative and With Project Alternative in SE-1 and NE-2, respectively are

presented in Tables 5.5 and 5.6 (SE-1 and NE-2 represent the subunits in which the

cuts are located). As stages increase in Lake Maurepas due to RSLR, the flow in

the proposed new conveyance channels increase (Table 5.4). RSLR would

dramatically reduce the stage duration below 1.0 foot with both the No-Action

Alternative and the With Project Alternative (Tables 5.5 and 5.6). The percentage of

days with water surface elevation below 1.0 foot in the SE-1 and NE-2 areas falls

from 37 and 48 percent, respectively, to zero under all three RSLR cases. It was

determined that little differences existed between all seven alternatives, when

modeled separately and together, therefore the With Project Alternative represents

the implementation of all cuts.

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Table 5.4. Computed Exchange Channel Flows with RSLR

With project with no RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 6330 5298 4812 4368 4035

% time of inflow 23% 22% 29% 28% 28%

Volume outflow (ac-ft/yr) 6874 7160 3392 3696 4088

% time of outflow 77% 78% 71% 72% 72%

With Project with 50 years of Low rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 23175 20734 14522 13503 12903

% time of inflow 35% 34% 54% 53% 52%

Volume outflow (ac-ft/yr) 32635 35202 7291 8187 8894

% time of outflow 65% 66% 46% 47% 48%

With Project with 50 years of Intermediate rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 28332 25659 15172 14131 13480

% time of inflow 36% 35% 56% 55% 54%

Volume outflow (ac-ft/yr) 41868 45382 7324 8397 9234

% time of outflow 64% 65% 44% 45% 46%

With Project with 50 years of High rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 36013 33138 15622 14617 14028

% time of inflow 39% 38% 56% 54% 52%

Volume outflow (ac-ft/yr) 57802 63338 74145 9374 11222

% time of outflow 61% 62% 44% 46% 48%

308
Table 5.5. Stage Duration with RSLR, Storage Area SE-1 1

No-Action Plan With Project Plan

Without RSLRWater Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 213 2283 2742 2935 3059 3151 1352 2390 2770 2950 3070 3160% time at or below WSE 6% 62% 75% 80% 84% 86% 37% 65% 76% 81% 84% 86%Consecutive Days at or below WSE 73 120 138 164 203 204 114 121 152 164 203 205With Project with Low rate of RSLR (50 years)Water Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 15 60 89 120 0 8 62 104 162 206% time at or below WSE 0% 0% 0% 2% 2% 3% 0% 0% 2% 3% 4% 6%Consecutive Days at or below WSE 0 0 2 7 9 12 0 2 7 10 16 22With Project with Intermediate rate of RSLR (50 years)Water Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 3 7 0 0 3 12 24 38% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1% 1%Consecutive Days at or below WSE 0 0 0 0 1 2 0 0 1 3 3 3With Project with High rate of RSLR (50 years)Water Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%Consecutive Days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0

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Table 5.6. Stage Duration with RSLR, Storage Area NE-2 3

No-Action Plan With Project Plan

Without RSLR

Water Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 241 2306 2834 3027 3144 3233 1750 2501 2865 3032 3153 3236% time at or below WSE 7% 63% 78% 83% 86% 88% 48% 68% 78% 83% 86% 89%

Consecutive Days at or below WSE 64 148 184 203 204 205 117 150 185 204 204 205With Project with Low rate of RSLR (50 years)Water Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 2 63 140 205 285 0 11 77 144 214 289% time at or below WSE 0% 0% 2% 4% 6% 8% 0% 0% 2% 4% 6% 8%

Consecutive Days at or below WSE 0 2 8 12 17 22 0 5 8 12 17 22With Project with Intermediate rate of RSLR (50 years)Water Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 1 19 40 60 0 0 4 23 42 66% time at or below WSE 0% 0% 0% 1% 1% 2% 0% 0% 0% 1% 1% 2%

Consecutive Days at or below WSE 0 0 1 3 3 8 0 0 2 3 3 5With Project with High rate of RSLR (50 years)Water Surface Elevation (WSE), feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 000000000000% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Consecutive Days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0

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Estimates of the time in years to permanent inundation for the No-Action

Alternative and Future with Project Alternative Plans (conditions are nearly the

same for both swamp areas) are presented in Table 5.7. These estimates do not

consider a rate for biomass and mineral sediment accretion. Biomass and mineral

sediment accretion could extend the timeline until permanent inundation. It is

estimated that within a healthy freshwater swamp habitat, accretion would result

in approximately 8 mm/year within the study area (Bernard Wood, unpublished

data, 2005 through 2009). It has also estimated that a net loss of substrate of 1 to 3

mm/year would occur within degraded areas of the Maurepas Swamp; therefore, a

net accretion rate of 2.2 to 4.6 mm/year in healthy areas of the Maurepas Swamp

(Shaffer and Bernard, unpublished data, 2005 through 2009). The net accretion

estimates account for subsidence, but not eustatic sea level rise.

Table 5.7. Years to Permanent Inundation

RSLR Case RSLR Year 50 No-Action With Project

Low Rate 1.5 feet 14 years 40 years

Intermediate Rate 1.9 feet 12.5 years 31 years

High Rate 3.2 feet 8 years 17 years

The rates of sea level rise and the rate of accretion relative to the existing

elevation of the swamp is depicted for reference in Figures 5.3 through 5.5. These

graphs illustrate that under the FWP condition, accretion will not keep up with

RSLR for any of the three forecasts. However, the figures do illustrate that a

substantial reduction of the RSLR impacts under the FWOP condition is obtained.

As stated in Section 3.5.2, benefits will be achieved even after permanent

inundation occurs. Therefore, the reduction in the impacts of RSLR observed

through biomass accretion would prolong the benefits obtained and increase

sustainability for all three estimates.

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Figure 5.3. Combined Effects of Low RSLR

Estimate and Accretion

Figure 5.4. Combined Effects of Intermediate RSLR

Estimate and Accretion

-2

-1.5

-1

-0.5

0

0.5

1

1.5

Feet

Year

Impacts of Sea Level Rise (Low), Subsidence,

and Accretion

Subsidence

FWP Accretion

RSLR, Low

FWP RSLR + Accr., Low

Current Ground Elevation

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

Feet

Year

Impacts of Sea Level Rise (Intermediate),

Subsidence, and Accretion

Subsidence

FWP Accretion

RSLR, Int.

FWP RSLR + Accr., Int.

Current Ground Elevation

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Figure 5.5. Combined Effects of High RSLR

Estimate and Accretion

As part of the analysis of RSLR in the Future With Project (FWP) condition,

the Wetland Value Analysis model (WVA) was performed on all three scenarios of

predicted sea level rise for the NER plan and the Recommended Plan. The results

showed a decrease of approximately seven percent when the intermediate estimate

was modeled and a decrease of approximately 10 percent with the high estimate.

The results of this analysis may be seen in Table 5.8.

Table 5.8. Effect of RSLR on Alternatives

Effect of Relative Sea Level Rise on Alternatives

Alternative Low SLR

(AAHUs)

Intermediate RSLR

(AAHUs)

High RSLR

(AAHUs)

33 679 640 610

34 589

35 334

36 1,268

37 922

38 1,013

39 1,602 1,516 1,452

Results of Relative Sea Level Rise Analysis - Proposed conveyance

channels would meet the hydrodynamic objectives of the project. Proposed

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Feet

Year

Impacts of Sea Level Rise (High), Subsidence,

and Accretion

Subsidence

FWP Accretion

RSLR, High

FWP RSLR + Accr., High

Current Ground Elevation

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conveyance channels would improve the hydrologic connections of the ARDC and

the adjacent swamp, as well as facilitating development of a more natural wet-dry

cycle within the swamp. The effects of RSLR would reduce the improvements by

reducing the dry periods within the associated areas of impact. Increased

connectivity for water flow, nutrients, and sediments will still benefit the

freshwater swamp, even in the event of permanent inundation. As stated in

Section 3.5.2, low oxygen and reducing conditions restrict tree growth in inundated

conditions. Improved flow would increase oxygen and improve tree vigor, even in

fully inundated conditions (Gary Shaffer, personal communication, October 2009).

It has also been recognized that organic material would accumulate in the

ARDC study area, thereby playing a role in reducing the overall effects of relative

RSLR. According to studies performed near the study area, organic buildup of

approximately 8 mm/yr has been observed near healthy cypress trees over the past

10 years (Bernard Wood, unpublished data, 2005 through 2009). This indicates that

accretion, within a healthy swamp with adequate sediment and nutrient exchange,

may reduce the potential impacts of RSLR.

The proposed conveyance channels may cause an inconsequential increase in

peak flood stages in the swamps near the ARDC, and a minor decrease in peak flood

stages in the Amite River and ARDC. The Recommended Plan would not increase

the flood risk to houses and developments within the study area.

Any future development along the dredged material berms within the areas

of impact would have no effect on the benefits generated by the final array of

alternatives, as hydrologic connectivity would still be established between the

ARDC and the interior swamp habitat.

5.2.1 Flow and Water Levels

5.2.1.1 No-Action Alternative

Direct. No direct impacts to flow and water levels, except there would be an

increase in water levels due to sea level rise.

Indirect. Indirect impacts of not implementing wetland restoration would

result in the persistence of existing conditions. Water flow into and out of the

swamp would remain inhibited by the dredged material berms, resulting in

continued impoundment of, and lack of connectivity to the adjacent swamp habitat.

This continued impoundment and lack of connectivity would continue to stress and

degrade the swamp habitat, converting from fresh marsh to open water.

Cumulative. Cumulative impacts of not implementing restoration actions

and reconnecting hydrologic flows between the Maurepas Swamp and adjacent

waters would result in the continued degradation and conversion of 18,204 acres of

existing swamp habitat to marsh and shallow open water habitat. Water flows into

and out of the swamp would continue to be impeded by the existing dredged

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material berms along the ARDC. Water levels within the impounded study area

would likely increase due to projected rise in sea level. The conversion of 18,204

acres of existing swamp habitat to a shallow open water system would be in

addition to other swamp habitat losses and degradation impacts to flows and water

levels throughout the region, state and nation (see Figure 5.1 and Table 5.2).

5.2.1.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts would be an increase in water flow into and out of the

swamp areas, along with more variable water levels indicative of a more natural

wet-dry cycles for 1,602 acres of swamp, depending on ARDC stages and tidal

activity. With added conveyance, increases in flow and water level fluctuations

would occur within more interior portions of the project area.

Indirect. The addition of three cuts in the ARDC dredged material berm

would reconnect the hydrology and increase flows into and out of 1,602 acres of

swamp, resulting in positive effects on water levels and flows. There would be an

overall net gain of 679 Average Annual Habitat Units (AAHUs).

Cumulative. Cumulative impacts to water flow and water levels would

primarily be associated with incremental impacts of similar wetland restoration

projects in and near the study area as well as throughout coastal Louisiana (see

Figure 5.1 and Table 5.2). Water levels would likely fluctuate in response to ARDC

and sea level rises, which would likely have a cumulative effect when considering

the overall freshwater swamp degradation in the Lake Maurepas area.

5.2.1.3 Alternative 34

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan) except increased flow and water level variability would occur in 1,459 acres of

swamp.

Indirect. Indirect impacts would be similar to Alternative 33 (Recommended

Plan) except that this alternative would benefit 1,459 acres (589 AAHUs).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan) except 1,459 acres of swamp would be benefited.

5.2.1.4 Alternative 35

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan) except increased flow and water level variability would occur in 820 acres of

swamp.

Indirect. Indirect impacts would be similar to Alternative 33 (Recommended

Plan) except that this alternative would benefit 820 acres (334 AAHUs).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan) except 820 acres of swamp would be benefited.

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5.2.1.5 Alternative 36

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan) except increased flow and water level variability would occur in 3,061 acres of

swamp.

Indirect. Indirect impacts would be similar to Alternative 33 (Recommended

Plan) except that this alternative would benefit 3,061 acres (1,268 AAHUs).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan) except 3,061 acres of swamp would be benefited.

5.2.1.6 Alternative 37

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan) except increased flow and water level variability would occur in 2,279 acres of

swamp.

Indirect. Indirect impacts would be similar to Alternative 33 (Recommended

Plan) except that this alternative would benefit 2,279 acres (922 AAHUs).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan) except 2,279 acres of swamp would be benefited.

5.2.1.7 Alternative 38

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan) except increased flow and water level variability would occur in 2,422 acres of

swamp.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan) except that this alternative would benefit 2,422 acres (1,013

AAHUs).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan) except 2,422 acres of swamp would be benefited.

5.2.1.8 Alternative 39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan) except increased flow and water level variability would occur in 3,881 acres of

swamp.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan) except that this alternative would benefit 3,881 acres (1,602

AAHUs).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan) except 3,881 acres of swamp would be benefited.

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5.2.2 Sedimentation and Erosion

5.2.2.1 No-Action Alternative

Direct. There would be no direct impacts to sediment supply to or from the

swamp. The sediment in the waters of the ARDC is primarily suspended fines that

would be prevented from entering the swamp by the dredged material berms of the

ARDC. The sediment would not be able to be supplied to the system, increasing the

impacts of erosion, subsidence, and swamp degradation.

Indirect. The swamp health would continue to degrade due to the lack of

connectivity and lack of sediment and nutrient input.

Cumulative. Cumulative effects include the continued impaired sediment

supply due to urbanization and the resulting degradation of coastal wetlands, as

well as the benefits and impacts of other state and Federal projects in the vicinity

(see Figure 5.1 and Table 5.2). Subsidence and RSLR would likely continue to occur

at a rate greater than sediment deposition, resulting in a net lowering of land

surface throughout much of coastal Louisiana. Within the study area, tropical

storms may cause some redistribution of sediments to and from the swamp and

surrounding waterways, but the ARDC existing dredged material berms would

continue to block hydrologic exchange and, therefore, sedimentation. Overall

cumulative impacts include the conversion of 18,204 acres of swamp to a shallow

open water system, which would be additive with other swamp losses and

degradation impacts to sedimentation and erosion throughout the region and state.

5.2.2.2 Alternative 33 (Recommended Plan)

Direct. The direct impact would be the connectivity and sediment accretion

from the ARDC into the swamp system on approximately 1,602 acres. The

appropriate BMPs would be implemented to limit the introduction of sediments into

receiving waters, such as the ARDC, during construction.

Indirect. The indirect benefits would improve swamp health due to the

connectivity and placement of sediment on the swamp floor on approximately 1,602

acres.

Cumulative. Cumulative impacts to sediments would primarily be

associated with incremental impacts of similar wetland creation and nourishment

features. Cumulative impacts would be the effect of the additive combination of

impacts and benefits for overall net acres nourished, and protected by other

Federal, state, local, and private restoration efforts (see Figure 5.1 and Table 5.2).

Alternative 33 (Recommended Plan) would interact with these projects to provide

an increase in the introduction of sediments for the swamp habitat within the

western Maurepas Swamp, thereby benefiting 1,602 acres, which would have a

cumulative effect when considering the overall freshwater swamp degradation in

the Lake Maurepas area. This would reduce the conversion of the estimated 18,204

acres of swamp to open water. Further development and other factors, such as sea

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level rise, would continue to have a negative effect, leading to further swamp

degradation within coastal Louisiana.

5.2.2.3 Alternative 34

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan), except the settlement of sediment on the swamp floor would occur over

approximately 1,459 acres.

Indirect. The indirect impacts would be similar to Alternative 33

(Recommended Plan), except accretion and improved swamp health would occur

over approximately 1,459 acres of swamp floor.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 1,459 acres of swamp would be benefited.

5.2.2.4 Alternative 35

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan), except the settlement of sediment on the swamp floor would occur over

approximately 820 acres.

Indirect. The indirect impacts would be similar to Alternative 33

(Recommended Plan), except accretion and improved swamp health would occur

over approximately 820 acres of swamp floor.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 820 acres of swamp would be benefited.

5.2.2.5 Alternative 36

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan), except the settlement of sediment on the swamp floor would occur over

approximately 3,061 acres.

Indirect. The indirect impacts would be similar to Alternative 33

(Recommended Plan), except accretion and improved swamp health would occur

over approximately 3,061 acres of swamp floor.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 3,061 acres of swamp would be benefited.

5.2.2.6 Alternative 37

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan), except the settlement of sediment on the swamp floor would occur over

approximately 2,279 acres.

Indirect. The indirect impacts would be similar to Alternative 33

(Recommended Plan), except accretion and improved swamp health would occur

over approximately 2,279 acres of swamp floor.

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Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 2,279 acres of swamp would be benefited.

5.2.2.7 Alternative 38

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan), except the settlement of sediment on the swamp floor would occur over

approximately 2,422 acres.

Indirect. The indirect impacts would be similar to Alternative 33

(Recommended Plan), except accretion and improved swamp health would occur

over approximately 2,422 acres of swamp floor.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 2,422 acres of swamp would be benefited.

5.2.2.8 Alternative 39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan), except the settlement of sediment on the swamp floor would occur over

approximately 3,881 acres.

Indirect. The indirect impacts would be similar to Alternative 33

(Recommended Plan), except accretion and improved swamp health would occur

over approximately 3,881 acres of swamp floor.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 3,881 acres of swamp would be benefited.

5.2.3 Water Use and Supply

5.2.3.1 No-Action Alternative

Direct. There would be no direct impacts to water use and supply.

Indirect. There would be no indirect impacts to water use and supply.

Cumulative. Water use would increase with population growth, placing

more demand on the water supply. Other cumulative impacts include the

conversion of 18,204 acres of swamp to a shallow open water system within the

study area, which would be additive with other swamp losses and degradation

impacts to water use and supply throughout the region and state. This conversion

of swamp habitat to open water habitat would likely reduce water purification

function of forested wetlands. However, the impacts to water use and supply within

the study area and vicinity would be offset to some extent by other Federal, state,

local, and private restoration efforts across coastal Louisiana (see Figure 5.1 and

Table 5.2).

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5.2.3.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct effects to water use and supply as a result

of Alternative 33 (Recommended Plan).

Indirect. There would be no indirect effects to water use and supply as a

result of Alternative 33 (Recommended Plan).

Cumulative. Water use and supply would likely continue to increase

throughout the country and region, while implementation of Alternative 33

(Recommended Plan) and the corresponding reconnected hydrology of swamp would

likely result in improved water purification function within the study area. The

impacts to water use and supply within the study area and vicinity would be

additive to some extent with other Federal, state, local, and private restoration

efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.2.3.3 Alternatives 34-39

Direct. There would be no direct effects to water use and supply.

Indirect. There would be no indirect effects to water use and supply.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.2.4 Groundwater

5.2.4.1 No-Action Alternative

Direct. There would be no direct impacts to groundwater.

Indirect. Indirect adverse impacts include decreases in groundwater

resources as a result of increased demand for groundwater as a water supply source

due to the increasing populations of Ascension and Livingston Parishes.

Cumulative. Cumulative impacts would include the overall reduction of

groundwater due to population, agriculture and industry increases throughout

coastal Louisiana. Increasing populations in Ascension and Livingston Parishes are

expected to stress groundwater resources by increased demands for groundwater as

a water supply. Overall cumulative impacts include the conversion of 18,204 acres

of swamp to a shallow open water system, which would be additive with other

swamp losses and degradation impacts to groundwater throughout the region and

state. However, the impacts to groundwater within the study area and vicinity

would be offset to some extent by other Federal, state, local, and private restoration

efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.2.4.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct effects on groundwater.

Indirect. There would be no indirect effects on groundwater.

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Cumulative. Rising populations in Ascension and Livingston Parishes are

expected to stress groundwater resources by increased demands for groundwater as

a water supply. No groundwater impacts would likely result upon implementation

of Alternative 33 (Recommended Plan) within the study area as groundwater is

supplied by the Chicot Equivalent aquifer. The impacts to groundwater within the

study area and vicinity would be additive to some extent with other Federal, state,

local, and private restoration efforts across coastal Louisiana (see Figure 5.1 and

Table 5.2).

5.2.4.3 Alternatives 34-39

Direct. There would be no direct effects on groundwater.

Indirect. There would be no indirect effects on groundwater.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.3 WATER QUALITY AND SALINITY

A draft Total Maximum Daily Load (TMDL) has been submitted by the Louisiana

Department of Environmental Quality (LDEQ) and proposes a 60 percent reduction

in non-point source (NPS) load within the ARDC in order to achieve current water

quality standards. However, the LDEQ is in the process of conducting an

ecoregional use attainability analysis that they suspect will modify the water

quality standard such that the required NPS load reduction will be reduced to

25 percent.

5.3.1 Water Quality

5.3.1.1 No-Action Alternative

Direct. There would be no direct impacts to water quality.

Indirect. Potential indirect impacts include further degradation of the

cypress-tupelo swamp due to the lack of water exchange. Current water quality

conditions would persist in surface waters in the impounded swamp habitat

adjacent to the ARDC and within the flowing systems. Conversion of the forested

swamp to fresh marsh and ultimately open water would cause changes to surface

water chemistry, including a seasonal increase in salinity as salt water moves more

easily upstream from Lake Maurepas, and the potential for the release of nutrients

that are currently retained in the swamp soils. The water quality within the swamp

would contribute to the continued degradation of the swamp due to the increased

stress on the plants because of the lack of connectivity and to the conversion of the

swamp, initially to fresh marsh, and ultimately to open water.

Cumulative. While the impending implementation of the TMDLs in the

study area would likely offset any new impacts from an increased human presence

in the region, the No-Action Alternative would likely result in changes to water

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quality as the forested swamp continues to degrade to fresh marsh and ultimately

open water. Continued conversion of swamp habitat to marsh and open water

throughout the region would reduce the natural filtration of water. Overall

cumulative impacts include the conversion of 18,204 acres of swamp to a shallow

open water system, which would be additive with other swamp losses and

degradation impacts to water quality throughout the region and state. However, the

impacts to water quality within the study area and vicinity would be offset to some

extent by other Federal, state, local, and private restoration efforts across coastal

Louisiana (see Figure 5.1 and Table 5.2).

Draft TMDLs have been received for the two LDEQ subsegments that

encompass the study area and are scheduled to be completed in 2011 for the current

causes of the Fish and Wildlife Propagation use impairment, including mercury,

chloride, and total dissolved solids (TDS). Water quality conditions in the study

area and vicinity could possibly improve the implementation of the TMDLs in

conjunction with other existing water quality programs. However, the potential

increase in human activities that could have adverse effects on water quality would

also continue to occur in the future, such as increased wastewater and polluted

stormwater runoff generated by increased development in the Pontchartrain Basin,

and the potential discharge of untreated or poorly-treated sewerage.

5.3.1.2 Alternative 33 (Recommended Plan)

Direct. Implementation of Alternative 33 (Recommended Plan) would

directly impact water quality by introducing sediments into both the ARDC and into

the swamps. Water introduction would temporarily increase total suspended and

dissolved solids and turbidity in the swamp. Appropriate BMPs should be used to

minimize the amount of sediment entering the ARDC and receiving waterbodies,

both during and after construction, until dredged material berms are vegetated.

There would also be some minor and temporary adverse direct impacts to water

quality due to increased turbidity during and immediately following the

construction phase.

Restoring hydraulic connectivity would temporarily and periodically allow

impounded swamp waters that are potentially low in dissolved oxygen (DO), and

high in biological oxygen demand (BOD), chlorides and nutrient content to enter the

ARDC and receiving waterbodies. The introduction of waters of poorer quality from

the swamp may impair the water quality in the receiving waters. Alternatively,

water with presumably higher DO and lower BOD, chlorides and nutrient content

would be allowed to flow into the forested swamp areas, thus improving the water

quality within the swamp. These higher quality waters, in conjunction with the

other benefits of this project, are expected to improve the health of the forested

swamp.

Indirect. Indirect impacts include the improvement of water quality

conditions within the forested swamp, thereby indirectly improving the growth and

health of the cypress-tupelo forest. There would also be some minor and temporary

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adverse impacts to water quality due to increased turbidity during and immediately

following the construction phase.

Cumulative. Increases in demand corresponding with increased human

population and industrialization within the region would likely create a potential

for water quality problems within the U.S. and Louisiana. The cumulative impacts

of implementing Alternative 33 (Recommended Plan) may include temporary and

periodic impacts to the water quality in the receiving waters within the study area,

but ultimately should improve water quality conditions, and the overall health of

the forested swamp, with the additional benefits that the healthy and intact

forested wetland environment would provide for 1,602 acres. The impacts to water

quality within the study area and vicinity would be additive to some extent with

other Federal, state, local, and private restoration efforts across coastal Louisiana

(see Figure 5.1 and Table 5.2).

5.3.1.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.3.2 Salinity

5.3.2.1 No-Action Alternative

Direct. Storm surges from tropical cyclone events would increase salinity

levels within the study area. The existing impoundments would retain higher

salinity water within the study area and cause it to absorb into the substrate. The

frequency of saltwater inundation is expected to increase with RSLR.

Indirect. Vegetation within the impounded forested swamp areas would be

subject to salt stress when saline waters are not freely flushed from the system.

Flora and fauna species may change over time as salt-tolerant species replace fresh

water species as the swamp turns to marsh and open water.

Cumulative. Cumulative impacts would include the negative impacts of

increased salinity levels moving further inland along coastal Louisiana, which leads

to the degradation of wetland vegetation and furthers coastal and bottomland

habitat loss, together with the benefits and impacts of other state and Federal

projects in the vicinity. The regional effects of RSLR may also play a role in

increasing salinity levels within the region. Within the study area, the continual

impoundment and lack of hydrologic connectivity would likely result in higher

residence times and higher salinity levels. Overall cumulative impacts include the

conversion of 18,204 acres of swamp to a shallow open water system, which would

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be additive with other swamp losses and degradation throughout the region and

state. However, the impacts to salinity levels within the study area and vicinity

would be offset to some extent by other Federal, state, local, and private restoration

efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.3.2.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts of Alternative 33 (Recommended Plan) would include

the introduction of fresh water into 1,602 acres of forested swamp, reducing the

salinity, chloride, and total dissolved solids concentrations within the impacted

areas.

Indirect. Existing vegetation within the impounded forested swamp areas

should benefit by the input of fresh water to the system. The implementation of

Alternative 33 (Recommended Plan) would partially restore the cycle of inundation

and drying of the swamp that halted with the construction of dredged material

berms. The periodic introduction of freshwater would help to decrease salt water

retention or absorption in the study area, thus helping to prevent the continued

degradation of the forested wetland.

Cumulative. The regional effects of RSLR may play a role in increasing

salinity levels within the surrounding areas of coastal Louisiana. The cumulative

impacts of implementing Alternative 33 (Recommended Plan) may include the

reduction of salinity levels within the study area due to the restored hydrologic

connectivity of 1,602 acres of swamp habitat. The impacts to salinity levels within

the study area and vicinity would be additive to some extent with other Federal,

state, local, and private restoration efforts across coastal Louisiana (see Figure 5.1

and Table 5.2).

5.3.2.3 Alternative 34

Direct. Direct impacts would be similar to that in Alternative 33

(Recommended Plan), although slightly reduced in scale because fewer cuts are

proposed in Alternative 34 and a smaller area of swamp would be impacted.

Indirect. Indirect impacts would be similar to that in Alternative 33

(Recommended Plan), although slightly reduced in scale because fewer cuts are

proposed in Alternative 34 and a smaller area of swamp would be impacted.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 1,459 acres of swamp habitat would benefit from

restored hydrologic connectivity.

5.3.2.4 Alternative 35

Direct. Direct impacts would be similar to that in Alternative 33

(Recommended Plan), although greatly reduced in scale because only one cut is

proposed in Alternative 35 and a smaller area of swamp would be impacted.

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Indirect. Indirect impacts would be similar to that in Alternative 33

(Recommended Plan), although greatly reduced in scale because only one cut is

proposed in Alternative 35 and a smaller area of swamp would be impacted.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 820 acres of swamp habitat would benefit from

restored hydrologic connectivity.

5.3.2.5 Alternative 36

Direct. Direct impacts would be similar to that in Alternative 33

(Recommended Plan), although increased in scale because one additional cut is

proposed in Alternative 36 and a larger area of swamp would be impacted.

Indirect. Indirect impacts would be similar to that in Alternative 33

(Recommended Plan), although increased in scale because one additional cut is

proposed in Alternative 36 and a larger area of swamp would be impacted.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 3,061 acres of swamp habitat would benefit from

restored hydrologic connectivity.

5.3.2.6 Alternative 37

Direct. Direct impacts would be similar to that in Alternative 33

(Recommended Plan), although reduced in scale, because one less cut is proposed in

Alternative 37; however a larger area of swamp would be impacted.

Indirect. Indirect impacts would be similar to that in Alternative 33

(Recommended Plan), although reduced in scale because one less cut is proposed in

Alternative 37; however a larger area of swamp would be impacted.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 2,279 acres of swamp habitat would benefit from

restored hydrologic connectivity.

5.3.2.7 Alternative 38

Direct. Direct impacts would be similar to that in Alternative 33

(Recommended Plan), although slightly increased in scale because one additional

cut is proposed in Alternative 38 and a larger area of swamp would be impacted.

Indirect. Indirect impacts would be similar to that in Alternative 33

(Recommended Plan), although slightly increased in scale because one additional

cut is proposed in Alternative 38 and a larger area of swamp would be impacted.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 2,422 acres of swamp habitat would benefit from

restored hydrologic connectivity.

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5.3.2.8 Alternative 39

Direct. Direct impacts would be similar to that in Alternative 33

(Recommended Plan), although greatly increased in scale because two additional

cuts are proposed and a larger area of swamp would be impacted.

Indirect. Indirect impacts would be similar to that in Alternative 33

(Recommended Plan), although greatly increased in scale because two additional

cuts are proposed and a larger area of swamp would be impacted.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except 3,881 acres of swamp habitat would benefit from

restored hydrologic connectivity.

5.4 AIR QUALITY

5.4.1 No-Action Alternative

Direct. There would be no direct adverse impacts on air quality.

Indirect. There would be no indirect impacts of not implementing

hydrologic connectivity within the study area, which would result in the persistence

of existing conditions. Most of the study area consists of remote, uninhabited

swamp.

Cumulative. Continued institutional recognition, along with the continued

deterioration of air quality throughout the nation and region, due to increases in

population and industrialization, would likely occur. Other cumulative impacts

include the conversion of 18,204 acres of swamp to a shallow open water system

within the study area, which would be additive with other swamp losses and

degradation impacts to air quality throughout the region and state, because of

reductions in function of swamp vegetation to act as natural filters for air pollution.

However, the impacts to air quality within the study area and vicinity would be

offset to some extent by other Federal, state, local, and private restoration efforts

across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.4.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts to ambient air quality would be temporary and

localized, resulting primarily from the emissions of construction equipment within

the study area. Direct impacts to air quality, specifically emission levels for nitrous

oxide (NOx) and volatile organic compounds (VOCs) are quantified in Tables 5.9

and 5.10.

Indirect. Over the 50-year period of analysis, Alternative 33 (Recommended

Plan) would likely result in the restoration of 1,602 acres of swamp vegetation,

increasing the habitat’s ability to filter the air and improve local air quality by

reducing particulates and gaseous air pollutants.

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Cumulative. Continued deterioration of air quality throughout the nation

and region, due to increases in population and industrialization, would likely occur.

These impacts to air quality within the study area and vicinity would be additive to

some extent with other Federal, state, local, and private restoration efforts across

coastal Louisiana (see Figure 5.1 and Table 5.2).

5.4.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.5 NOISE

5.5.1 No-Action Alternative

Direct. There would be no direct impacts on noise.

Indirect. There would be no indirect impacts on noise.

Cumulative. There would be no cumulative impacts of the No-Action

Alternative on noise.

5.5.2 Alternative 33 (Recommended Plan)

Direct. Construction activities associated with implementing Alternative 33

(Recommended Plan) would temporarily increase the noise levels in the

construction areas. However, the areas of impact are remote and unpopulated, so

the noise level would not affect any nearby human communities. In some instances,

noise impacts may directly impact fish and wildlife species temporarily. These

organisms would generally avoid the construction area; returning once construction

activities cease. Potential noise impacts from construction activities, although

construction equipment is limited in the level of noise that can be emitted.

Institutional recognition of noise, such as provided by the regulation for

Occupational Noise Exposure 929 CFR Part 1910.95) under the Occupational Safety

and Health Act of 1970, as amended, would continue. This section mandates that

noise levels emitted from construction equipment be below 90 dB for exposures of

eight hours per day or more. Once construction activities are completed, noise

levels would return to preconstruction conditions.

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Table 5.9. Air Quality Emission Analysis for Nitrous Oxide 1

2

This table lists the equipment that will be used for the earth moving phase of this project, and details an estimate of 3the amount of expected emission of Nitrous Oxide for the duration of the project. 4

56

Air Quality Emission Analysis for Nitrous Oxide

Units Equipment Item

Total

Work

Hours

Work

House Per

Unit

Fuel

Type

Gas Diesel hp

Multiplying

Factor % hp Time

Total

hp Hours

Annual

hp Hours

1 Crew Boat 880 880 D 874 0.83 0.8 510695.68 510695.681 Dozer D-6 400 400 D 100 0.83 0.7 23240 232401 Log Skidder 517 400 400 D 120 0.83 0.7 27888 278881 Marsh Backhoe/CAT 330 1680 1680 D 222 0.83 0.7 216689.76 216689.761 Tugboat 900 horsepower (hp) 160 160 D 900 0.83 0.8 95616 956161 Barge 840 840 0 0 0

TOTAL GASOLINE (hp hours)TOTAL DIESEL (hp hours) 874129.44 874129.441Nox Emission Factors (lbs/hp hours) Gas Diesel

0.011 0.031

Emissions TonsGas 0.002Diesel 13.55

Subtotal 13.55

1Nox emission factors were obtained per guidance AP 42. Additional information may be obtained at www.epa.gov/ttnchie1/ap42/.2Estimated Nox emissions were calculated by multiplying total diesel hp hours by the diesel Nox emission factor (lbs/hp hours), divided by 2000 to obtain tons (874129.44*0.031/2000).

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5.10. Air Quality Emission Analysis for Volatile Organic Compounds 9

10

This table lists the equipment that will be used for the earth moving phase of this project, and details an estimate of 11the amount of expected emission of Volatile Organic Compounds for the duration of the project. 12

1314

Air Quality Emission Analysis for Volatile Organic Compounds

Units Equipment Item

Total

Work

Hours

Work House

Per Unit

Fuel Type

Gas Diesel hp

Multiplying

Factor % hp Time

Total

hp Hours

Annual

hp Hours

1 Crew Boat 880 880 D 874 0.83 0.8 510695.68 510695.681 Dozer D-6 400 400 D 100 0.83 0.7 23240 232401 Log Skidder 517 400 400 D 120 0.83 0.7 27888 278881 Marsh Backhoe/CAT 330 1680 1680 D 222 0.83 0.7 216689.76 216689.761 Tugboat 900 hp 160 160 D 900 0.83 0.8 95616 956161 Barge 840 840 0 0 0

874129.44 874129.44 1VOC Emission Factors

(lbs/hp hours) Gas Diesel

Exhaust 0.015 0.00247Evaporation 0.000661 0 Emissions TonsCrankcase 0.00485 0.0000441 Gas 0.00Refueling 0.00108 0 2Diesel 1.10Total 0.021591 0.0025141 Subtotal 1.10 1VOC emission factors were obtained per guidance AP 42. Additional information may be obtained at www.epa.gov/ttnchie1/ap42/. 2Estimated VOC emissions were calculated by multiplying total diesel hp hours by the total diesel VOC emission factors (lbs/hp hours), divided by 2000 to obtain tons

(874129.44*0.0025141/2000).

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Indirect. Localized and temporary noise impacts would likely result in

wildlife and fishery resources, temporarily leaving the areas of impact during

construction activities, reducing the wildlife viewing opportunities. However,

indirect impacts due to noise are expected to be localized, temporary, and minor.

Cumulative. The cumulative impacts would principally be related to the

potential short-term disruption of fish and wildlife species. The continued increases

in noise throughout the nation and region, due to increases in population and

industrialization, would likely occur. Ambient noise from boats, airboats, and other

human activities would continue to cause some minimal and temporary

disturbances in the study area. Long-term adverse cumulative impacts within the

study area due to noise levels are not expected.

5.5.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.6 VEGETATION RESOURCES

5.6.1 Riparian Vegetation Resources

5.6.1.1 No-Action Alternative

Direct. There would be no direct impacts to riparian vegetation.

Indirect. There would essentially be no impact to riparian vegetation.

Cumulative. Riparian vegetation along ARDC berms likely unchanged over

50-year period of analysis. However, the impacts to riparian vegetation resources

within the study area and vicinity would be offset to some extent by other Federal,

state, local, and private restoration efforts across coastal Louisiana (see Figure 5.1

and Table 5.2).

5.6.1.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts would include the loss of riparian vegetation

resources located along the ARDC dredged material berms to open water habitat

due to the construction of the conveyance channel (Figure 3.4). There would be

approximately 16,101 linear feet of conveyance channel created and approximately

7.4 acres of riparian habitat created adjacent to the channel. All riparian habitats

temporarily impacted or created would be replanted for the improvement of this

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habitat. The dredged material placement berms would be replanted with the

appropriate BLH species, and the rest of the area impacted by the construction of

the conveyance channel and dredged material placement would be planted with

freshwater swamp species.

Indirect. There would be minor indirect impacts to riparian habitat due to

effects of the construction.

Cumulative. This alternative would have positive effects on riparian

vegetation when combined with other Federal, state, local, and private restoration

efforts (see Figure 5.1 and Table 5.2). There would be creation of riparian habitat

along conveyance channels. Riparian vegetation on dredged material berms would

be impacted by construction

5.6.1.3 Alternative 34

Direct. Direct impacts would include the conversion of riparian vegetation

resources located along the ARDC dredged material berms due to the construction

of the conveyance channel (Figure 3.10). There would be approximately 8,483 linear

feet on conveyance channel created and approximately 3.9 acres of riparian habitat

created adjacent to the channel. All riparian habitats temporarily impacted or

created would be replanted for the improvement of this habitat. The dredged

material placement berms would be replanted with the appropriate BLH species,

and the rest of the area impacted by the construction of the conveyance channel and

dredged material placement would be planted with freshwater swamp species.

Indirect. There would be minor indirect impacts to riparian habitat.

Cumulative. Cumulative impacts would include the direct minor loss of

riparian habitat due to construction of the conveyance channel and the conversion

of 3.9 acres of freshwater swamp to riparian habitat. Overall cumulative impacts

would be similar to Alternative 33 (Recommended Plan).

5.6.1.4 Alternative 35

Direct. Direct impacts would include the conversion of riparian vegetation

resources located along the ARDC dredged material berms due to the construction

of the conveyance channel (Figure 3.11). There would be approximately 5,930

linear feet on conveyance channel created and approximately 2.7 acres of riparian

habitat created adjacent to the channel. All riparian habitats temporarily impacted

or created would be replanted for the improvement of this habitat. The dredged

material placement berms would be replanted with the appropriate BLH species,

and the rest of the area impacted by the construction of the conveyance channel and

dredged material placement would be planted with freshwater swamp species.

Indirect. There would be minor indirect impacts to riparian habitat.

Cumulative. Cumulative impacts would include the direct minor loss of

riparian habitat due to construction of the conveyance channels and the conversion

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of 2.7 acres of freshwater swamp to riparian habitat. Overall cumulative impacts

would be similar to Alternative 33 (Recommended Plan).

5.6.1.5 Alternative 36

Direct. Direct impacts would include the conversion of riparian vegetation

resources located along the ARDC dredged material berms due to the construction

of the conveyance channel (Figure 3.12). There would be approximately 24,493

linear feet on conveyance channel created and approximately 11.3 acres of riparian

habitat created adjacent to the channel. All riparian habitats temporarily impacted

or created would be replanted for the improvement of this habitat. The dredged

material placement berms would be replanted with the appropriate BLH species,

and the rest of the area impacted by the construction of the conveyance channel and

dredged material placement would be planted with freshwater swamp species.

Indirect. There would be minor indirect impacts to riparian habitat.

Cumulative. Cumulative impacts would include the direct minor loss of

riparian habitat due to construction of the conveyance channels and the conversion

of 11.3 acres of freshwater swamp to riparian habitat. Overall cumulative impacts

would be similar to Alternative 33 (Recommended Plan).

5.6.1.6 Alternative 37

Direct. Direct impacts would include the conversion of riparian vegetation

resources located along the ARDC dredged material berms due to the construction

of the conveyance channel (Figure 3.13). Approximately 10.1 acres of freshwater

swamp would be converted into riparian habitat; approximately 4.9 would be

converted dredged material placement and 5.2 acres would be cleared work areas

(Table 3.4). There would be approximately 14,413 linear feet on conveyance

channel created and approximately 6.7 acres of riparian habitat created adjacent to

the channel. All riparian habitats temporarily impacted or created would be

replanted for the improvement of this habitat. The dredged material placement

berms would be replanted with the appropriate BLH species, and the rest of the

area impacted by the construction of the conveyance channel and dredged material

placement would be planted with freshwater swamp species.

Indirect. There would be minor indirect impacts to riparian habitat.

Cumulative. Cumulative impacts would include the direct minor loss of

riparian habitat due to construction of the conveyance channels and the conversion

of 6.7 acres of freshwater swamp to riparian habitat. Overall cumulative impacts

would be similar to Alternative 33 (Recommended Plan).

5.6.1.7 Alternative 38

Direct. Direct impacts would include the conversion of riparian vegetation

resources located along the ARDC dredged material berms due to the construction

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of the conveyance channel (Figure 3.14). There would be approximately 21,940

linear feet on conveyance channel created and approximately 10.1 acres of riparian

habitat created adjacent to the channel. All riparian habitats temporarily impacted

or created would be replanted for the improvement of this habitat. The dredged

material placement berms would be replanted with the appropriate BLH species,

and the rest of the area impacted by the construction of the conveyance channel and

dredged material placement would be planted with freshwater swamp species.

Indirect. There would be minor indirect impacts to riparian habitat.

Cumulative. Cumulative impacts would include the direct minor loss of

riparian habitat due to construction of the conveyance channel and the conversion

of 15.2 acres of freshwater swamp to riparian habitat and the conversion of 10.1

acres of freshwater swamp to riparian habitat. Overall cumulative impacts would

be similar to Alternative 33 (Recommended Plan).

5.6.1.8 Alternative 39

Direct. Direct impacts would include the conversion of riparian vegetation

resources located along the ARDC dredged material berms would be permanently

lost due to the construction of the conveyance channel (Figure 3.15). There would

be approximately 30,423 linear feet on conveyance channel created and

approximately 14.0 acres of riparian habitat created adjacent to the channel. All

riparian habitats temporarily impacted or created would be replanted for the

improvement of this habitat. The dredged material placement berms would be

replanted with the appropriate BLH species, and the rest of the area impacted by

the construction of the conveyance channel and dredged material placement would

be planted with freshwater swamp species.

Indirect. There would be minor indirect impacts to riparian habitat.

Cumulative. Cumulative impacts would include the direct minor loss of

riparian habitat due to construction of the conveyance channel and the conversion

of 14 acres of freshwater swamp to riparian habitat and the conversion of 7.4 acres

of freshwater swamp to riparian habitat. Overall cumulative impacts would be

similar to Alternative 33 (Recommended Plan).

5.6.2 Wetland Vegetation Resources

The acres of vegetative degradation resulting from the No-Action alternative and

the acres of freshwater swamp and bottomland hardwood habitat benefited through

implementation of the final array are found in Table 5.11.

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Table 5.11. Degradation and Benefits for Final Array

Years to Marsh

Study Area

Degradation

(Acres)

Benefits Achieved from Final Array (Acres)

No-Action 33 34 35 36 37 38 39

Existing Marsh 300 144 146 0 290 146 144 290

10 Years to Marsh 1,723 241 775 0 1,016 775 241 1,016

20 - 3- Years to Marsh 7,979 975 299 542 1,274 841 1,518 1,816

30 - 50 Years to Marsh 8,202 242 239 278 481 517 519 759

Total Acres 18,204 1,602 1,459 820 3,061 2,279 2,422 3,881

5.6.2.1 No-Action Alternative

Direct. There would be no direct impacts to wetland vegetation resources.

Indirect. The lack of connectivity for freshwater, nutrient, and sediment

exchange would continue to degrade the wetland habitat. Additionally,

impoundment caused by the dredged material berms would continue to cause

degradation to the freshwater swamp habitat. The freshwater swamp would

degrade to freshwater marsh and eventually to open water. Functions lost include

habitat for wildlife and aquatic species, recreational opportunities, aesthetics, and

storm surge protection. Upon severe degradation, the swamp will convert to

freshwater marsh, then to open water. The freshwater marsh does offer some of the

functions of the freshwater swamp, but certain functions are lost, such as habitat

for avian species and storm surge protection.

Cumulative. Cumulative impacts would be the continued degradation effects

of coastal land loss due to hydrologic impairment, development, subsidence, sea

level rise, and saltwater intrusion. Other cumulative impacts include the conversion

of 18,204 acres of swamp to a shallow open water system within the study area,

which would be additive with other swamp losses and degradation impacts to

wetland vegetation throughout the region and state. However, the impacts to

wetland vegetation resources within the study area and vicinity would be offset to

some extent by other Federal, state, local, and private restoration efforts across

coastal Louisiana (see Figure 5.1 and Table 5.2).

5.6.2.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts would include the conversion of approximately

31.2 acres of existing cypress/tupelo swamp and dredged material berm habitat

vegetated by upland plants to open water conveyance channel habitat and BLH

habitat (Figure 3.4). Approximately 18.6 acres would be converted to conveyance

channel, 5.0 acres would be converted to dredged material placement berm habitat,

and 7.6 acres would be temporarily impacted by the construction (Table 3.4).

Temporary work areas would be replanted with freshwater swamp species, and the

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dredged material berms would be planted with appropriate BLH species. The

vegetative plantings on 438 acres would be conducted by hand and would have no

significant direct impacts on existing wetland vegetation, but would contribute to

the improved health of the freshwater swamp system.

Indirect. This alternative would improve the hydrologic connectivity

between the ARDC and 1,602 acres in both the primary and secondary impact areas

(Figure 3.4), creating approximately 679 AAHUs of freshwater swamp. Restored

hydrologic connections would increase the nutrient and sediment loads to 646 acres

within the primary impact area. Additional indirect impacts would include

increased acreage of swamp wetland vegetation habitats used by fish and wildlife

for shelter, nesting, feeding, roosting, cover, nursery, and other life requirements;

increased vegetation growth and productivity; and reduced inter- and intra- specific

competition between resident and migratory fish and wildlife species for limited

coastal swamp wetland vegetation resources. Compared to the No-Action

Alternative, implementing this alternative would prevent the conversion of 1,602

acres of existing swamp wetland vegetation habitats to marsh and shallow open

water habitats. Increased connectivity for water flow, nutrients, and sediments will

benefit the freshwater swamp, even in the event of permanent inundation. Low

oxygen and reducing conditions restrict tree growth in inundated conditions.

Improved flow would increase oxygen and improve tree vigor, even in fully

inundated conditions (Gary Shaffer, personal communication, October 2009).

Cumulative. Alternative 33 (Recommended Plan) would restore

approximately 1,602 acres with a total of 679 AAHUs compared to the No-Action

Alternative. However, throughout the region, state and nation, the continued

deterioration and loss of wetland vegetation resources would likely continue due to

natural and human-induced processes. The impacts to wetland vegetation resources

within the study area and vicinity would be additive to some extent with other

Federal, state, local, and private restoration efforts across coastal Louisiana (see

Figure 5.1 and Table 5.2).

5.6.2.3 Alternative 34

Direct. Direct impacts would include the conversion of approximately

18.8 acres of existing cypress/tupelo swamp and dredged material berm habitat

vegetated by upland plants to open water conveyance channel habitat and BLH

habitat (Figure 3.10). Approximately 10.5 acres would be converted to conveyance

channel, 2.7 acres would be converted to dredged material placement berm habitat,

and 5.6 acres would be temporarily impacted by the construction. The acreages

associated with direct impacts are found in Table 3.5. Temporary work areas would

be replanted with freshwater swamp species, and the dredged material berms

would be planted with appropriate BLH species. The vegetative plantings on 487

acres would be conducted by hand and would have no significant direct impacts on

existing wetland vegetation, but would contribute to the improved health of the

freshwater swamp system.

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Indirect. This alternative would improve the hydrologic connectivity

between the ARDC and 1,459 acres in both the primary and secondary impact areas

(Figure 3.10), creating approximately 589 AAHUs of freshwater swamp. Restored

hydrologic connections would increase the nutrient and sediment loads to 426 acres

within the primary impact area.

Cumulative. Alternative 34 would restore approximately 1,459 acres with a

total of 589 AAHUs compared to the No-Action Alternative. However, throughout

the region, state and nation, the continued deterioration and loss of wetland

vegetation resources would likely continue due to natural and human-induced

processes.

5.6.2.4 Alternative 35

Direct. Direct impacts would include the conversion of approximately

13.3 acres of existing cypress/tupelo swamp and dredged material berm habitat

vegetated by upland plants to open water conveyance channel habitat and BLH

habitat (Figure 3.11). Approximately 7.2 acres would be converted to conveyance

channel, 2.2 acres would be converted to dredged material placement berm habitat,

and 3.9 acres would be temporarily impacted by the construction. The acreages

associated with direct impacts are found in Table 3.5. Temporary work areas would

be replanted with freshwater swamp species, and the dredged material berms

would be planted with appropriate BLH species. There would be no vegetative

plantings.

Indirect. This alternative would improve the hydrologic connectivity

between the ARDC and 820 acres in both the primary and secondary impact areas

(Figure 3.11), creating approximately 334 AAHUs of freshwater swamp. Restored

hydrologic connections would increase the nutrient and sediment loads to 443 acres

within the primary impact area.

Cumulative. Alternative 35 would restore approximately 820 acres with a

total of 334 AAHUs compared to the No-Action Alternative. However, throughout

the region, state and nation, the continued deterioration and loss of wetland

vegetation resources would likely continue due to natural and human-induced

processes.

5.6.2.5 Alternative 36

Direct. Direct impacts would include the conversion of approximately

50.0 acres of existing cypress/tupelo swamp and dredged material berm habitat

vegetated by upland plants to open water conveyance channel habitat and BLH

habitat (Figure 3.12). Approximately 29.1 acres would be converted to conveyance

channel, 7.8 acres would be converted to dredged material placement berm habitat,

and 13.1 acres would be temporarily impacted by the construction. The acreages

associated with direct impacts are found in Table 3.5. Temporary work areas would

be replanted with freshwater swamp species, and the dredged material berms

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would be planted with appropriate BLH species. The vegetative plantings on 925

acres would be conducted by hand and would have no significant direct impacts on

existing wetland vegetation, but would contribute to the improved health of the

freshwater swamp system.

Indirect. This alternative would improve the hydrologic connectivity

between the ARDC and 3,061 acres in both the primary and secondary impact areas

(Figure 3.12), creating approximately 1,268 AAHUs. Restored hydrologic

connections would increase the nutrient and sediment loads to 1,072 acres within

the primary impact area.

Cumulative. Alternative 36 would restore approximately 3,061 acres with a

total of 1,268 AAHUs compared to the No-Action Alternative. However, throughout

the region, state and nation, the continued deterioration and loss of wetland

vegetation resources would likely continue due to natural and human-induced

processes.

5.6.2.6 Alternative 37

Direct. Direct impacts would include the conversion of approximately

32.1 acres of existing cypress/tupelo swamp and dredged material berm habitat

vegetated by upland plants to open water conveyance channel habitat and BLH

habitat (Figure 3.13). Approximately 17.7 acres would be converted to conveyance

channel, 4.9 acres would be converted to dredged material placement berm habitat,

and 9.5 acres would be temporarily impacted by the construction. Temporary work

areas would be replanted with freshwater swamp species, and the dredged material

berms would be planted with appropriate BLH species. The vegetative plantings on

487 acres would be conducted by hand and would have no significant direct impacts

on existing wetland vegetation, but would contribute to the improved health of the

freshwater swamp system.

Indirect. This alternative would improve the hydrologic connectivity

between the ARDC and 2,279 acres in both the primary and secondary impact areas

(Figure 3.13), creating approximately 922 AAHUs of freshwater swamp. Restored

hydrologic connections would increase the nutrient and sediment loads to 869 acres

within the primary impact area.

Cumulative. Alternative 37 would restore approximately 2,279 acres with a

total of 922 AAHUs compared to the No-Action Alternative. However, throughout

the region, state and nation, the continued deterioration and loss of wetland

vegetation resources would likely continue due to natural and human-induced

processes.

5.6.2.7 Alternative 38

Direct. Direct impacts would include the conversion of approximately

44.5 acres of existing cypress/tupelo swamp and dredged material berm habitat

vegetated by upland plants to open water conveyance channel habitat and BLH

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habitat (Figure 3.14). Approximately 25.8 acres would be converted to conveyance

channel, 7.2 acres would be converted to dredged material placement berm habitat,

and 11.5 acres would be temporarily impacted by the construction. The acreages

associated with direct impacts are found in Table 3.5. Temporary work areas would

be replanted with freshwater swamp species, and the dredged material berms

would be planted with appropriate BLH species. The vegetative plantings on 438

acres would be conducted by hand and would have no significant direct impacts on

existing wetland vegetation, but would contribute to the improved health of the

freshwater swamp system.

Indirect. This alternative would improve the hydrologic connectivity

between the ARDC and 2,422 acres in both the primary and secondary impact

areas, creating approximately 1.013 AAHUs of freshwater swamp (Figure 3.14).

Restored hydrologic connections would increase the nutrient and sediment loads to

1,088 acres within the primary impact area.

Cumulative. Alternative 38 would restore approximately 2,422 acres with a

total of 1,013 AAHUs compared to the No-Action Alternative. However, throughout

the region, state and nation, the continued deterioration and loss of wetland

vegetation resources would likely continue due to natural and human-induced

processes.

5.6.2.8 Alternative 39

Direct. Direct impacts would include the conversion of approximately

63.3 acres of existing cypress/tupelo swamp and dredged material berm habitat

vegetated by upland plants to open water conveyance channel habitat and BLH

habitat (Figure 3.15). Approximately 36.3 acres would be converted to conveyance

channel, 9.9 acres would be converted to dredged material placement berm habitat,

and 17.1 acres would be temporarily impacted by the construction. The acreages

associated with direct impacts are found in Table 3.5. Temporary work areas would

be replanted with freshwater swamp species, and the dredged material berms

would be planted with appropriate BLH species. The vegetative plantings on 925

acres would be conducted by hand and would have no significant direct impacts on

existing wetland vegetation, but would contribute to the improved health of the

freshwater swamp system.

Indirect. This alternative would improve the hydrologic connectivity

between the ARDC and 3,881 acres in both the primary and secondary impact areas

(Figure 3.15), creating approximately 1,602 AAHUs of freshwater swamp. Restored

hydrologic connections would increase the nutrient and sediment loads to 1,515

acres within the primary impact area.

Cumulative. Alternative 39 would restore approximately 3,881 acres with a

total of 1,602 AAHUs compared to the No-Action Alternative. However, throughout

the region, state and nation, the continued deterioration and loss of wetland

vegetation resources would likely continue due to natural and human-induced

processes.

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5.6.3 Upland Vegetation Resources

5.6.3.1 No-Action Alternative

Direct. There would be no direct impacts to upland vegetation.

Indirect. The significant amount of upland vegetation existing in the study

area is on the existing spoil bank and would likely remain even as the surrounding

swamp converts to open water. Therefore there would be no indirect impact to the

No-Action alternative.

Cumulative. The significant amount of upland vegetation existing in the

study area is on the existing spoil bank and would likely remain even as the

surrounding swamp converts to open water. Therefore there would be no

cumulative effect with the No-Action alternative.

5.6.3.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts to upland vegetation would result from the

construction activities associated with the dredging of new conveyance channels

through the existing dredged material berm, as well as the placement of dredged

material to create upland islands along these conveyance channels. Approximately

0.8 acre of existing berm would be permanently impacted to create part of the

conveyance channel, while approximately 1.8 acres would be temporarily impacted

for the construction of cuts through existing berms. The acreages associated with

direct impacts are found in Table 3.5. Vegetative plantings under this alternative

would encompass 5.0 acres of newly created upland habitat.

Indirect. No indirect impacts to upland vegetation as a result of Alternative

33 (Recommended Plan) are expected. Existing upland communities within the

areas of impact are stable and would not be significantly altered.

Cumulative. Changes to cumulative impacts within existing upland

vegetation would be minimal for this alternative. The impacts to upland vegetation

resources within the study area and vicinity would be additive to some extent with

other Federal, state, local, and private restoration efforts across coastal Louisiana

(see Figure 5.1 and Table 5.2).

5.6.3.3 Alternative 34

Direct. The direct impact of this alternative would be similar to Alternative

33 (Recommended Plan). Alternative 34 would permanently impact approximately

0.9 acre of upland habitat for the construction of the conveyance channels. In

addition, approximately 2.5 acres of existing berm would be temporarily impacted

for the construction of cuts in existing berms. Vegetative plantings under this

alternative would encompass 2.7 acres of newly created upland habitat.

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Indirect. No indirect impacts to upland vegetation are expected. Existing

upland communities within the areas of impact are stable and would not be

significantly altered during construction.

Cumulative. Changes to cumulative impacts within existing upland

vegetation would be minimal for this alternative. Overall

cumulative impacts would be similar to Alternative 33 (Recommended Plan).

5.6.3.4 Alternative 35

Direct. The direct impact of this alternative would be similar to Alternative

33 (Recommended Plan). Alternative 35 would permanently impact approximately

0.6 acre of upland habitat for the construction of the conveyance channels. In

addition, approximately 1.8 acres of existing berm would be temporarily impacted

for the construction of cuts in existing berms. The acreages associated with direct

impacts are found in Table 3.5. Vegetative plantings under this alternative would

encompass 2.2 acres of newly created upland habitat.

Indirect. No indirect impacts to upland vegetation are expected. Existing

upland communities within the areas of impact are stable and would not be

significantly altered.

Cumulative. Changes to cumulative impacts within existing upland

vegetation would be minimal for this alternative. Overall cumulative impacts would

be similar to Alternative 33 (Recommended Plan).

5.6.3.5 Alternative 36

Direct. The direct impact of this alternative would be similar to Alternative

33 (Recommended Plan). Alternative 36 would permanently impact approximately

1.7 acres of upland habitat for the construction of the conveyance channels. In

addition, approximately 4.3 acres of existing berm would be temporarily impacted

for the construction of cuts in existing berms. The acreages associated with direct

impacts are found in Table 3.5. Vegetative plantings under this alternative would

encompass 7.8 acres of newly created upland habitat.

Indirect. No indirect impacts to upland vegetation are expected. Existing

upland communities within the areas of impact are stable and would not be

significantly altered.

Cumulative. Changes to cumulative impacts within existing upland

vegetation would be minimal for this alternative. Overall cumulative impacts would

be similar to Alternative 33 (Recommended Plan).

5.6.3.6 Alternative 37

Direct. The direct impact of this alternative would be similar to Alternative

33 (Recommended Plan). Alternative 37 would permanently impact approximately

1.5 acres of upland habitat for the construction of the conveyance channels. In

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addition, approximately 4.3 acres of existing berm would be temporarily impacted

for the construction of cuts in existing berms. The acreages associated with direct

impacts are found in Table 3.5. Vegetative plantings under this alternative would

encompass 4.9 acres of newly created upland habitat.

Indirect. No indirect impacts to upland vegetation are expected. Existing

upland communities within the areas of impact are stable and would not be

significantly altered.

Cumulative. Changes to cumulative impacts within existing upland

vegetation would be minimal for this alternative. Overall cumulative impacts

would be similar to Alternative 33 (Recommended Plan).

5.6.3.7 Alternative 38

Direct. The direct impact of this alternative would be similar to Alternative

33 (Recommended Plan), with the following exceptions. Alternative 38 would

permanently impact approximately 1.4 acre of upland habitat for the construction of

the conveyance channels. The acreages associated with direct impacts are found in

Table 3.5. In addition, approximately 3.6 acres of existing berm would be

temporarily impacted for the construction of cuts in existing berms. Vegetative

plantings under this alternative would encompass 7.2 acres of newly created upland

habitat.

Indirect. No indirect impacts to upland vegetation as a result of

Alternative 38 are expected. Existing upland communities within the areas of

impact are stable and would not be significantly altered.

Cumulative. Changes to cumulative impacts within existing upland

vegetation would be minimal for this alternative. Overall cumulative impacts

would be similar to Alternative 33 (Recommended Plan).

5.6.3.8 Alternative 39

Direct. The direct impact of this alternative would be similar to Alternative

33 (Recommended Plan). Alternative 39 would permanently impact approximately

2.3 acres of upland habitat for the construction of the conveyance channels. In

addition, approximately 6.1 acres of existing berm would be temporarily impacted

for the construction of cuts in existing berms. The acreages associated with direct

impacts are found in Table 3.5. Vegetative plantings under this alternative would

encompass 9.9 acres of newly created upland habitat.

Indirect. No indirect impacts to upland vegetation are expected. Existing

upland communities within the areas of impact are stable and would not be

significantly altered during construction.

Cumulative. Changes to cumulative impacts within existing upland

vegetation would be minimal for this alternative. Overall cumulative impacts

would be similar to Alternative 33 (Recommended Plan).

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5.6.4 Submerged Aquatic Vegetation (SAV)

5.6.4.1 No-Action Alternative

Direct. There would be no direct impacts to the SAV community.

Indirect. The submerged aquatic community would continue to change as

the swamp changes to marsh and open water.

Cumulative. Cumulative impacts would be the effects from wetland loss

and degradation throughout coastal Louisiana. However, the impacts to SAV

within the study area and vicinity would be offset to some extent by other Federal,

state, local, and private restoration efforts across coastal Louisiana (see Figure 5.1

and Table 5.2).

5.6.4.2 Alternative 33 (Recommended Plan)

Direct. Alternative 33 (Recommended Plan) would directly impact any SAV

communities along the ARDC by mechanical crushing during construction. These

impacts would be temporary and the vegetative community would quickly rebound.

Most SAV communities would receive no direct impact as a result of proposed

management activities.

Indirect. Cutting through existing berms and creating conveyance channels

would indirectly affect SAV habitat by creating additional habitat.

Cumulative. Cumulative impacts would be the effects from wetland loss and

degradation throughout coastal Louisiana. The impacts to SAV within the study area

and vicinity would be additive to some extent with other Federal, state, local, and

private restoration efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.6.4.3 Alternatives 34-39

Direct. The direct impact would be similar to Alternative 33 (Recommended

Plan).

Indirect. The indirect impact would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.6.5 Invasive Species Vegetation

5.6.5.1 No-Action Alternative

Direct. There would be no direct impacts to invasive vegetation.

Indirect. Invasive species would continue to spread, as the swamp converts

to marsh and open water.

Cumulative. Invasive vegetation would continue to increase, as it would in

south Louisiana, the region, and the country. However, the impacts to invasive

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vegetation species within the study area and vicinity would be offset to some extent

by other Federal, state, local, and private invasive species control efforts across

coastal Louisiana (see Figure 5.1 and Table 5.2).

5.6.5.2 Alternative 33 (Recommended Plan)

Direct. Invasive vegetation within the construction zones may be negatively

affected by construction activities by direct removal, crushing or burial. In all three

cases, these impacts are expected to be temporary and the remaining plants would

likely regenerate quickly in the disturbed areas of the study area.

Indirect. Restored connectivity and the planting of native vegetation would

somewhat reduce the proliferation of invasive species.

Cumulative. Invasive species would continue to proliferate within the study

area and Alternative 33 (Recommended Plan) would help to reduce this spread

because of the restored connectivity and planting of native vegetation. The invasive

species spread in the study area would be additive with the invasive species spread

throughout coastal Louisiana and the Nation. The positive impacts to invasive

vegetation species within the study area and vicinity would be additive to some

extent with other Federal, state, local, and private invasive species control efforts

across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.6.5.3 Alternatives 34-39

Direct. The direct impact would be similar to Alternative 33 (Recommended

Plan).

Indirect. The indirect impact would be similar to Alternative 33

(Recommended Plan).

Cumulative. The cumulative impact would be similar to Alternative 33

(Recommended Plan).

5.7 WILDLIFE HABITAT

5.7.1 No-Action Alternative

Direct. There would be no direct impacts to wildlife resources.

Indirect. Adverse indirect impacts on wildlife resources would result from

the continued conversion of 18,204 acres of primarily swamp habitat to marsh and

shallow open water habitats. Swamp areas used for foraging, nesting, and overwintering habitat would convert initially to fresh marsh, and ultimately to shallow

open water habitat. Swamp habitat quality would continue to decline as the swamp

continues to deteriorate. As the swamp areas convert to open water, species

richness would likely decline. The loss of swamp habitat and continued degradation

would likely result in competition for dwindling swamp resources and a localized

decrease in wildlife use of the area and movement of more mobile wildlife to more

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suitable areas. With the continued degradation of the swamp and the eventual

conversion to open water, feeding opportunities for bald eagles will decline. The

loss of freshwater swamp trees will decrease bald eagle nesting habitat. Similarly,

nesting trees available for colonial nesting wading bird colonies would also decline.

Cumulative. Cumulative impacts would include the conversion of 18,204 acres of

existing swamp habitat to a shallow open water system within the study area, which would

be additive with other swamp losses and degradation impacts locally, regionally, statewide

and nationwide. However, these negative impacts to wildlife habitat within the

study area and vicinity would be offset to some extent by the positive effects of other

Federal, state, local, and private restoration efforts across coastal Louisiana (see

Figure 5.1 and Table 5.2).

5.7.2 Alternative 33 (Recommended Plan)

Direct. Construction activities associated with implementation of

Alternative 33 (Recommended Plan) may disrupt or displace wildlife resources.

However, any such impacts would be localized and temporary, and most wildlife

species would temporarily relocate to nearby areas. No permanent displacement

would be expected from restoration activities as wildlife is expected to return when

project construction is completed. Conveyance channels would be constructed,

providing deepwater habitat in the swamp and allowing exchange of water,

nutrients, and sediments between the swamp and the ARDC and creation of habitat

for SAV, fish, and wildlife. Upland habitat created by the placement of the dredged

material will provide additional refuge for various wildlife species during high

water events. As a result of the public review process, the USFWS has requested

that a qualified biologist inspect the proposed worksite for the presence of

undocumented colonial wading bird nesting colonies and bald eagles during the

nesting season (i.e., February 16 through October 31 for colonial wading bird

nesting colonies and October through mid-May for bald eagles). In addition, it has

been recommended by the USFWS that construction activities and/or land clearing

be conducted during the fall or winter to minimize impacts to nesting migratory

birds, when practicable.

Indirect. Indirect impacts to wildlife resources would include the

restoration and creation of a net total of 1,602 acres of swamp and bottomland

hardwood "island" habitats, with a total of 679 AAHUs that would be utilized by

resident and migrant wildlife species for nesting, rearing of young, resting, and

foraging activities. Swamp creation/nourishment would also help to increase and

preserve important stopover habitat for neotropical migrants as well as wintering

habitat for waterfowl. The increase in tree canopy would improve bald eagle and

colonial waterbird nesting habitat. In addition, the quality of habitat would be

improved, which would increase the abundance of prey items for wildlife.

Cumulative. Cumulative impacts would be the additive effects restoring

1,602 acres of important fish and wildlife in combination with the impacts for

overall net acres restored, created, nourished, and protected by other Federal, state,

local, and private restoration efforts. The positive impacts to wildlife habitat within

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the study area and vicinity would be additive to some extent with other Federal,

state, local, and private restoration efforts across coastal Louisiana (see Figure 5.1

and Table 5.2).

5.7.3 Alternative 34

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33 (Recommended

Plan),

except approximately 1,459 acres of freshwater swamp habitat would be restored

and 589 AAHUs would be created.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except Alternative 34 would restore a net total of 1,459 acres

of freshwater swamp habitat with 589 AAHUs compared to the No-Action

Alternative.

5.7.4 Alternative 35

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Impacts would be similar to Alternative 33 (Recommended Plan),

except approximately 820 acres of freshwater swamp habitat would be restored and

334 AAHUs would be created.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except Alternative 35 would restore a net total of 820 acres of

freshwater swamp habitat with 334 AAHUs compared to the No-Action Alternative.

5.7.5 Alternative 36

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except approximately 3,061 acres of freshwater swamp

habitat would be restored and 1,268 AAHUs would be created.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except Alternative 36 would restore a net total of 3,061 acres

of freshwater swamp habitat with 1,268 AAHUs compared to the No-Action

Alternative

5.7.6 Alternative 37

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

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Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except approximately 2,279 acres of freshwater swamp

habitat would be restored and 922 AAHUs would be created.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except Alternative 37 would restore a net total of 2,279 acres

of freshwater swamp habitat with 922 AAHUs compared to the No-Action

Alternative.

5.7.7 Alternative 38

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except approximately 2,422 acres of freshwater swamp

habitat would be restored and 1,013 AAHUs would be created.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except Alternative 38 would restore a net total of 2,422 acres

of freshwater swamp habitat with 1,013 AAHUs compared to the No-Action

Alternative.

5.7.8 Alternative 39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan), except approximately 3,881 acres of freshwater swamp

habitat would be restored and 1,602 AAHUs would be created.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan), except Alternative 39 would restore a net total of 3,881 acres

of freshwater swamp

habitat with 1,602 AAHUs compared to the No-Action Alternative.

5.8 AQUATIC RESOURCES

5.8.1 Benthic

5.8.1.1 No-Action Alternative

Direct. Under the No-Action Alternative no direct adverse impacts to

benthic organisms would occur.

Indirect. Over time, indirect impacts of impoundment, limited hydrologic

connections between the interior swamp wetlands and the ARDC, swamp habitat

degradation and conversion to open water habitat would continue under the NoAction Alternative. These impacts would indirectly result in a decrease in the

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quality of benthic habitat within the study area, thereby reducing the area’s ability

to support benthic species. The persistence of existing conditions would result in the

continued conversion of 18,204 acres of existing swamp habitat to shallow water

habitat that would provide additional albeit poor quality benthic habitat. Other

indirect impacts would include a decrease of available nutrients and detritus.

Habitat quality would likely continue to degrade, creating a stressful environment

for those benthic and other aquatic species presently utilizing the area. Some

populations of benthic organisms would likely decrease, impacting other species in

the food web.

Cumulative. Cumulative impacts of the No-Action Alternative would

primarily be related to conversion of 18,204 acres of swamp and associated benthic

habitat to a shallow open water system. These impacts to benthic resources would

be in addition to other regional and Louisiana coast-wide swamp and benthic

habitat losses and degradation. The LCA Near-term Ecosystem Restoration Plan

(USACE, 2004) estimated a net loss of 328,000 acres of coastal wetland habitat

would occur by 2050. This is nearly 10 percent of Louisiana's remaining coastal

wetlands, which are utilized by various benthic species for shelter, foraging, cover,

nursery, and other life requirements. Benthic populations within Louisiana in

general and the study area in particular would likely continue to shift towards more

saline-oriented species as land loss and saltwater intrusion continue to affect

Louisiana's interior regions. These adverse cumulative impacts would be offset, to

some degree by the positive impacts associated with swamp and benthic habitats

restored created, nourished, and protected by other Federal, state, local, and private

restoration efforts (see Figure 5.1 and Table 5.2).

5.8.1.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts to benthic resources would generally be associated

with conveyance channel construction activities, including conversion of 0.8 acres of

ARDC dredged material berms and 17.8 acres of existing swamp habitat to

conveyance channel waterbottoms that would provide potential benthic habitat.

Approximately 18.6 acres of benthic habitat would be created by the conveyance

channel construction. These actions would directly impact and destroy any slowmoving or sessile benthic organisms found within the proposed excavation and berm

creation areas. More mobile benthic species utilizing the area would likely be

displaced. Other direct impacts to the benthos would be localized and confined to

construction areas. However, the prolific nature of the benthic community is

expected to result in rapid re-colonization of substrates once construction is

completed. In addition, benthic resources occur seasonally in the swamp and are

more abundant during winter months. Therefore, direct effects may vary depending

on the time of the year construction occurs.

Indirect. Indirect impacts to benthic resources would be related primarily to

disturbance of waterbottoms during placement of dredged material and dredging.

Short-term disturbance to benthic species would likely occur from increased

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turbidity, temperature, and BOD; and decreased dissolved oxygen due to dredging

and dredged material berm creation. Some smothering of benthic organisms may

also occur from dredge plume resettlement, but these impacts would be minimized

through the use of silt curtains or other construction measures to minimize

dredging impacts. Some indirect impacts would be localized and temporary;

however, the construction of conveyance channels and the decrease in habitat

degradation would alter the benthic community structure. A total of 1,602 acres of

swamp habitat would be restored by this alternative. Swamp habitat benefitted by

Alternative 33 (Recommended Plan) would indirectly benefit benthic resources by

providing increased dissolved organic compounds and detritus that would, in turn,

provide food and energy resources for benthic organisms.

Cumulative. Cumulative impacts would be the additive effects of restoring

1,602 acres of primarily swamp habitat resulting in greater resources for benthic

organisms due to the export of dissolved organic compounds and detritus from the

swamp. The net beneficial impacts would be in combination with the impacts for

overall net acres of swamp and benthic habitat restored created, nourished, and

protected by other Federal, state, local, and private restoration efforts (see

Figure 5.1 and Table 5.2).

5.8.1.3 Alternative 34

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 0.9 acre of berm and

9.6 acres of swamp will be converted to conveyance channel.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except 10.5 acres of conveyance channel

bottoms would be created and approximately 1,459 acres of freshwater swamp

would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.8.1.4 Alternative 35

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 0.6 acre of berm and

6.6 acres of swamp will be converted to conveyance channel.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except 7.2 acres of conveyance channel

bottoms would be created and approximately 820 acres of freshwater swamp would

be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

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5.8.1.5 Alternative 36

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 1.7 acres of berm and

27.4 acres of swamp will be converted to conveyance channel.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except 29.1 acres of conveyance channel

bottoms would be created and approximately 3,061 acres of freshwater swamp

would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.8.1.6 Alternative 37

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 1.5 acres of berm and

16.2 acres of swamp will be converted to conveyance channel.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except 17.7 acres of conveyance channel

bottoms would be created and approximately 2,279 acres of freshwater swamp

would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.8.1.7 Alternative 38

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 1.4 acres of berm and

24.4 acres of swamp will be converted to conveyance channel.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except 25.8 acres of conveyance channel

bottoms would be created and approximately 2,420 acres of freshwater swamp

would be benefited.

Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.8.1.8 Alternative 39

Direct. Direct impacts of this alternative would be similar to those described

for Alternative 33 (Recommended Plan), except approximately 2.3 acres of berm and

34 acres of swamp will be converted to conveyance channel.

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan), except 36.3 acres of conveyance channel

bottoms would be created and approximately 3,881 acres of freshwater swamp

would be benefited.

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Cumulative. Cumulative effects of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.8.2 Plankton

5.8.2.1 No-Action Alternative

Direct. There would be no direct adverse impacts to plankton resources.

Indirect. Adverse indirect impacts would result from the continued

conversion of swamp habitat, initially to fresh marsh, and ultimately to open water.

The projected habitat conversion would ultimately create unstable environment for

plankton resources.

Cumulative. Algal blooms would continue in the open waters within the

swamp as a result of the release of phosphorus sequestered in swamp sediments

into surface waters. Within coastal areas of Louisiana, plankton populations are

experiencing a shift towards more saline-oriented species as land loss and saltwater

intrusion continues. Other cumulative impacts include the conversion of 18,204

acres of swamp to a shallow open water system within the study area, which would

be additive with other swamp losses and degradation impacts to plankton resources

throughout the region and state (see Figure 5.1 and Table 5.2).

5.8.2.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts to plankton resources would generally be associated

with construction activities. Some species could suffer mortality or injury during

dredging and placement of borrow material. Construction activities would

negatively impact plankton populations by temporarily increase turbidity,

temperatures, and BOD; and decrease DO.

Indirect. Construction would create conveyance channels, providing

deepwater habitat in the swamp. The negative increases in turbidity and

temperature and a decrease in DO associated with these actions would be

temporary and localized. These conveyance channels would allow plankton access

into the interior swamp and create a more normal nutrient exchange between the

swamp and outside waters. Increased productivity, as a result of the 1,602 acres of

swamp habitat benefited by this alternative, would provide indirect benefits to

plankton by increasing nutrients and detritus.

Cumulative. Plankton resources would continue to be adversely impacted

by the coastal land loss and swamp degradation.

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5.8.2.3 Alternatives 34-39

Direct. Direct impacts would be similar to those described for Alternative 33

(Recommended Plan).

Indirect. Indirect impacts would be similar to those described for

Alternative 33 (Recommended Plan).

Cumulative. Cumulative impacts would be similar to those described for

Alternative 33 (Recommended Plan).

5.9 FISHERY RESOURCES

5.9.1 No-Action Alternative

Direct. There would be no direct impacts to fishery resources.

Indirect. Over time, indirect impacts of impoundment, limited hydrologic

connections between the interior swamp wetlands and the ARDC, swamp habitat

degradation, and conversion to open water would continue. These impacts would

indirectly result in a decrease in the quality of aquatic habitat within the study

area, thereby reducing the area’s ability to support fishery organisms. Some

populations of aquatic organisms would likely decrease, impacting other species in

the food web. The reduction in swamp wetlands habitat would also result in shifts

in predator/prey relationships as well as a potential decline in fishery productivity.

Recreational fishing opportunities would continue to be limited. Ingress and egress

access of fishery organisms to interior portions of the swamp would continue to be

limited due to dredged material berms along ARDC which block access. Swamp

habitat used by fishery organisms for shelter, nesting, feeding, cover, nursery, and

other life history requirements would continue to degrade and convert to shallow

open water habitat. Although the continued conversion of swamp habitat to open

water habitat would increase the amount of aquatic habitat available to fishery

resources, the quality of the aquatic habitat would likely continue to degrade,

creating a lower quality environment for fishery and other aquatic species.

Cumulative. Cumulative impacts of the No-Action Alternative would

primarily be related to the conversion of 18,204 acres of swamp habitat to a shallow

open water system. These impacts would be in addition to other Louisiana coastwide fishery habitat losses and degradation, as well as the impacts of other state

and Federal projects in the vicinity (see Figure 5.1 and Table 5.2). The LCA Nearterm Ecosystem Restoration Plan (USACE, 2004) estimated a net loss of 328,000

acres of coastal wetland habitat would occur by 2050. This is nearly 10 percent of

Louisiana's remaining coastal wetlands, which are utilized by various fish species

for shelter, foraging, cover, nursery, and other life requirements. However, fishery

populations within Louisiana in general and the study area in particular would

likely continue to shift towards more saline-oriented species as land loss and

saltwater intrusion continue to affect Louisiana's interior regions.

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5.9.2 Alternative 33 (Recommended Plan)

Direct. Direct impacts of implementing Alternative 33 (Recommended Plan)

on fishery organisms would generally be associated with construction activities,

including creation of 16,010 linear feet long of conveyance channel habitat.

Additional direct impacts would be the creation of 18.6 acres conveyance channel

habitat. Any sessile or slow moving fisheries species present could suffer mortality

or injury during the dredging and placement of borrow material. Construction

activities would temporarily increase turbidity, temperatures, and BOD; and

decrease DO. These temporary conditions could displace more mobile fisheries

species from the construction area. Following construction, displaced fisheries

species would likely return to the areas of impact. Overall, the direct impacts to

fishery resources are temporary and minor.

Indirect. Indirect impacts include the increased productivity, as a result of

hydrologic restoration of 1,602 acres of swamp habitat, and would provide an

increase in the energy inputs into the local food web. Sediment and nutrient

transport into the interior swamp areas would improve fishery productivity.

Increasing the health of the study area swamp and bottomland hardwood habitat

would support not only local fishery resources but would also contribute to

increasing the flow of detritus and other important components of the aquatic food

web from the interior wetland habitats to estuarine areas closer to the Gulf of

Mexico.

Cumulative. Cumulative impacts would be the additive effect of restoring

1,602 acres of primarily cypress/tupelo swamp habitat, with the combination of

impacts and benefits for the overall net acres benefitted by other Federal, state,

local, and private restoration efforts (see Figure 5.1 and Table 5.2). Swamp

restoration and reconnected hydrology would result in greater resources for aquatic

and fishery resources due to the increased export of dissolved organic compounds

and detritus from wetlands.

5.9.3 Alternative 34

Direct. Direct impacts would be similar to those described for Alternative 33

(Recommended Plan), except Alternative 34 would create 8,483 linear feet of

conveyance channel habitat for at total of 10.5 acres of deepwater aquatic habitat.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

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5.9.4 Alternative 35

Direct. Direct impacts would be similar to those described for Alternative 33

(Recommended Plan), except Alternative 35 would create 5,930 linear feet of

conveyance channel habitat for at total of 7.2 acres of deepwater aquatic habitat.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.9.5 Alternative 36

Direct. Direct impacts would be similar to those described for Alternative 33

(Recommended Plan), except Alternative 36 would create 24,493 linear feet of

conveyance channel habitat for at total of 29.1 acres of deepwater aquatic habitat.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.9.6 Alternative 37

Direct. Direct impacts would be similar to those described for

Alternative 33 (Recommended Plan), except Alternative 36 would create 14,413

linear feet of conveyance channel habitat for at total of 17.7 acres of deepwater

aquatic habitat.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.9.7 Alternative 38

Direct. Direct impacts would be similar to those described for Alternative 33

(Recommended Plan), except Alternative 38 would create 21,940 linear feet of

conveyance channel habitat for at total of 25.8 acres of deepwater aquatic habitat.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

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5.9.8 Alternative 39

Direct. Direct impacts would be similar to those described for Alternative 33

(Recommended Plan), except Alternative 39 would create 30,423 linear feet of

conveyance channel habitat for at total of 36.3 acres of deepwater aquatic habitat.

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts of this alternative would be similar to

those described for Alternative 33 (Recommended Plan).

5.10 ESSENTIAL FISH HABITAT (EFH)

5.10.1 No-Action Alternative

Direct. There would be no direct impacts to EFH.

Indirect. There is no EFH in the study area and there would be no indirect

impacts.

Cumulative. Cumulative impacts would be the additive combination of

similar impacts from wetland loss and degradation throughout coastal Louisiana, as

well as the benefits and impacts of other state and Federal projects in the vicinity

(see Figure 5.1 and Table 5.2).

5.10.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts to EFH.

Indirect. There would be no indirect impacts to EFH.

Cumulative. There would be no cumulative impacts to EFH.

5.10.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.11 THREATENED AND ENDANGERED SPECIES

5.11.1 No-Action Alternative

Direct. There would be no direct effects on threatened and endangered

species or their habitat.

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Indirect. General habitat loss for the study area would continue. Important

nesting, feeding, roosting, and nursery habitat within the study area would

continue to erode and convert to shallow open water

Cumulative. There would be a continued degradation and loss of fish and

wildlife habitat for shelter, nesting, feeding, roosting, cover, nursery, and other life

requirements in coastal Louisiana. Cumulative impacts would be the additive

combination of similar impacts from wetland loss and degradation throughout

coastal Louisiana, as well as, the benefits and impacts of other state and Federal

projects in the vicinity (see Figure 5.1 and Table 5.2).

5.11.2 Alternative 33 (Recommended Plan)

Direct. There is no critical habitat for the Gulf sturgeon in the study area.

The proposed action would not jeopardize the continued existence of the Gulf

sturgeon. Hence, the USACE has determined the proposed action is Not Likely to

Adversely Affect (NLAA) Gulf sturgeon or its critical habitat. Appendix A presents

a Biological Assessment that describes those factors used in determining the

potential impacts of the proposed action on the Gulf sturgeon.

Any effects to the West Indian manatee from implementing the proposed

action would be related to possible collision with service vessels during the

construction activities. All USACE personnel and all contractors would be informed

of the need to abide by the following procedures to avoid and minimize any impacts

to the manatees.

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) of 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 re-established.

(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 lightdisplacement 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

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at least 8-1/2" x 11" (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 SHUT DOWN 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.

Given the rare occurrence of manatees within the areas of impact, along with

the implementation of the above operational precautions, no collision fatalities are

expected.

Indirect. There would be no adverse indirect impacts of implementing

Alternative 33 (Recommended Plan) to any listed species. Rather, proposed marsh

nourishment would provide a net increase of transitional coastal wetland habitat by

increasing the quality of habitat; increasing species usage and diversity; and

providing for a net increase in habitats used for forage, breeding, spawning, and

cover. The increase in wetland acreage would provide increased detritus that would

be exported to ARDC water bottoms, thereby providing additional resources for the

benthic food chain that would in turn increase the availability of prey items for Gulf

sturgeon.

Indirect impacts to listed species would primarily be positive resulting from

the wetland nourishment features, which would provide a net creation and

nourishment of 1,602 acres of transitional swamp, compared to the No-Action

Alternative. However, there may be some temporary and localized minor effects on

the food supply for Gulf sturgeon as some of the ARDC water bottom would be

dredged to construct the conveyance channels. Any such impacts to the benthic food

supply are anticipated to be minor, as only a small fraction of the total ARDC water

bottom would be impacted, and the benthos would re-colonize dredged locations

rapidly following construction. There is no critical habitat for Gulf sturgeon in the

study area.

Cumulative. Cumulative impacts would be the additive effect with the

combination of impacts and benefits for overall net acres created and nourished by

other Federal, state, local, and private restoration efforts (see Figure 5.1 and

Table 5.2). Alternative 33 (Recommended Plan) would create and nourish a net

total of 1,602 acres of freshwater swamp. Although unlikely to impact populations

on a continental scale, those listed species that utilize the areas of impact would

also benefit from the cumulative effects of Alternative 33 (Recommended Plan) and

other restoration efforts in the area.

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5.11.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.12 CULTURAL AND HISTORIC RESOURCES

5.12.1 No-Action Alternative

Direct. There would be no direct impacts on historic and cultural resources.

Indirect. The eventual land loss within the study threatens the existence

and integrity of all cultural resources found within the study area.

Cumulative. Within the country and coastal Louisiana, the institutional

recognition of all cultural resources as a significant resource would likely continue,

along with their potential loss due to natural and human causes. The land loss

within the study area and throughout coastal Louisiana threatens the existence and

integrity of these resources. However, the impacts to cultural resources within the

study area and vicinity would be offset to some extent by other Federal, state, local,

and private restoration efforts preventing coastal erosion and protecting cultural

resources across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.12.2 Alternative 33 (Recommended Plan)

Direct. Alternative 33 (Recommended Plan), would have no direct impacts

on historic and cultural resources as there are no National Register of Historic

Places (NRHP) eligible or listed sites within the project area. Measures (see the

Programmatic Agreement located in Appendix F) would be put into place in the case

that any cultural resources are discovered during construction.

Indirect. Ecosystem restoration measures would prevent further land loss

and erosion in the areas of impact. This would benefit cultural and historic

resources in the study area by preventing the erosion that threatens their existence.

Cumulative. Cumulative impacts of the proposed action are related to the

increased stability of the wetland resources throughout the region. The reduction in

land loss and subsequent preservation of cultural resources within the study area

and vicinity would be additive to some extent with other Federal, state, local, and

private restoration efforts preventing coastal erosion and protecting cultural

resources across coastal Louisiana (see Figure 5.1 and Table 5.2).

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5.12.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.13 AESTHETICS

5.13.1 No-Action Alternative

Direct. There would be no direct beneficial or adverse impacts to aesthetic

resources.

Indirect. Conversion of existing bald cypress-tupelo swamp to fresh marsh

and ultimately to open water habitat would continue, possibly resulting in degraded

viewscapes for those traveling within the study area (along the ARDC). Habitat

degradation and conversion under the No-Action Alternative would also likely

impair the viewshed of the Blind River, a designated Scenic River.

Cumulative. Cumulative impacts would be the continued aesthetic losses

associated with the degradation of freshwater swamps throughout coastal

Louisiana, with the additive combination of similar impacts from wetland loss and

degradation throughout coastal Louisiana.

5.13.2 Alternative 33 (Recommended Plan)

Direct. Viewscapes would be minimally and temporarily disturbed by

construction activities. The immediate effects of construction activities, such as

grading and clearing of vegetation, would temporarily reduce the aesthetic value of

sections of the study area. Initially some of the study area would become

unvegetated. These minor impacts would be localized and temporary. The areas of

impact should quickly stabilize, and the newly created, nourished, and protected

wetlands would provide new high quality viewscapes as well as protect existing

ones. Plantings, along with existing wetland vegetation, would recolonize the area,

thereby increasing the scenic value of the areas of impact and surroundings through

increased visual complexity.

Indirect. The indirect impacts would primarily result from newly created

high quality emergent wetlands that would provide long term visual enhancement

of an area that is presently experiencing a decline in visual complexity.

Cumulative. The continued degradation of coastal Louisiana would lead to

degraded aesthetic resources. The implementation of Alternative 33 (Recommended

Plan) would have a positive cumulative impact. The impact to aesthetics within the

study area and vicinity would be additive to some extent with other Federal, state,

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local, and private restoration effects across coastal Louisiana (see Figure 5.1 and

Table 5.2).

5.13.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.14 RECREATION

5.14.1 No-Action Alternative

Direct. There would be no direct effect on recreation within the study area.

Indirect. There would be a continued loss and degradation of habitat in the

study area resulting in lost recreational opportunities, including fishing, wildlife

viewing, and hunting.

Cumulative. There would be a continued loss in Coastal Louisiana of

habitat resulting in lost recreational opportunities. The impacts to recreation

resources within the study area and vicinity would be offset to some extent by other

Federal, state, local, and private restoration efforts across coastal Louisiana (see

Figure 5.1 and Table 5.2).

5.14.2 Alternative 33 (Recommended Plan)

Direct. There would be minor, temporary, direct impacts to recreation.

Recreational boaters would have to slow and avoid some of the marine equipment

during construction.

Indirect. This alternative would have little effect on the level of boating

activity. The cuts in the dredged material berms of the ARDC and the conveyance

channels reaching into the interior of the swamps would provide spawning

opportunities for species of recreational importance. However, the improvement to

fisheries would be minimal and would not affect the level of fishing activity.

Alternative 33 (Recommended Plan) would have a minor positive effect on the

quality of hunting because of improvements to the aesthetics of the swamp and an

increase in the quality of the deer. However, the quantification of value is minor

because little hunting is done in the area that would be affected by the alternative.

There may be a minimal change in the level of hunting activity in the study area.

Hunting is limited to leaseholders and is not available to the general public.

Cumulative. The annual value of recreation would not increase to any

measurable extent under Alternative 33 (Recommended Plan). Approximately

1,602 acres of important stopover habitat (freshwater swamp) would be improved

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for migratory neotropical songbirds and waterfowl. The net positive impacts to

recreation resources within the study area and vicinity would be additive to some

extent with other Federal, state, local, and private restoration efforts across coastal

Louisiana (see Figure 5.1 and Table 5.2).

5.14.3 Alternatives 33-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15 SOCIOECONOMIC AND HUMAN RESOURCES

5.15.1 Population and Housing

5.15.1.1 No-Action Alternative

Direct. There would be no direct impact on population and housing in the

study area.

Indirect. There would be little to no indirect effect on population and

housing within the study area.

Cumulative. Populations within Ascension and Livingston Parishes would

continue their projected increases. The study area is not located in a highly

populated area. The impacts to population and housing within the study area and

vicinity would be additive to some extent with other Federal, state, local, and

private restoration efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.15.1.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts on population and housing within

the study area.

Indirect. There would be little to no indirect effect on population and

housing within the study area.

Cumulative. Populations within Ascension and Livingston Parishes would

continue their projected increases. The study area is not located in a highly

populated area; therefore, swamp nourishment and creation activities would likely

have no beneficial or adverse effects on population and housing. The impacts to

population and housing within the study area and vicinity would be additive to

some extent with other Federal, state, local, and private restoration efforts across

coastal Louisiana (see Figure 5.1 and Table 5.2).

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5.15.1.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.2 Employment and Income

5.15.2.1 No-Action Alternative

Direct. There would be no direct effect on employment and income.

Indirect. There would be no indirect effect on employment and income.

Cumulative. Employment and income level would continue to increase or

decline in coastal Louisiana according to the national and regional economic health.

The impacts to employment and income within the study area and vicinity would be

additive to some extent with other Federal, state, local, and private restoration

efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.15.2.2 Alternative 33 (Recommended Plan)

Direct. There would be a minor positive effect on temporary jobs and income

as a result on the implementation of Alternative 33 (Recommended Plan).

Indirect. There would be a temporary and minor positive effect on services

(goods, fuel, food, equipment rentals, etc.) from construction expenses related to

implementation of Alternative 33 (Recommended Plan).

Cumulative. There would be very little change in the cumulative effects.

Employment and income level would continue to increase or decline in coastal

Louisiana according to the national and regional economic health. The impacts to

employment and income within the study area and vicinity would be additive to

some extent with other Federal, state, local, and private restoration efforts across

coastal Louisiana (see Figure 5.1 and Table 5.2).

5.15.2.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

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5.15.3 Community Cohesion

5.15.3.1 No-Action Alternative

Direct. The No-Action Alternative would have no beneficial or adverse

direct impacts on community cohesion within the study area.

Indirect. The No-Action Alternative would have no beneficial or adverse

indirect impacts on community cohesion within the study area.

Cumulative. Cumulative impacts would be the additive combination of

similar impacts from wetland loss and degradation throughout coastal Louisiana.

Assuming existing proposed permits were completed, several of the current

subdivisions would expand, and a proposed bridge over the ARDC would improve

community cohesion. The impacts to community cohesion within the study area and

vicinity would be additive to some extent with other Federal, state, local, and

private restoration efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.15.3.2 Alternative 33 (Recommended Plan)

Direct. Alternative 33 (Recommended Plan) would have no beneficial or

adverse direct impacts on community cohesion within the study area.

Indirect. Alternative 33 (Recommended Plan) would have no beneficial or

adverse indirect impacts on community cohesion within the study area.

Cumulative. There would be no effect on the cumulative impacts on

community cohesion. The impacts to community cohesion within the study area

and vicinity would be additive to some extent with other Federal, state, local, and

private restoration efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.15.3.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.4 Environmental Justice

5.15.4.1 The No-Action Alternative

Direct. No minority and/or low-income communities have been identified in

the study area that would be adversely impacted by the No-Action Alternative.

Therefore, no disproportionately high or adverse human health or environmental

effects on minority or low-income populations would occur.

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Indirect. General habitat loss for the study area would continue; however,

no disproportionately high or adverse human health or environmental indirect

impacts on minority or low-income populations would occur as there are none

identified within the study area.

Cumulative. There would be no cumulative impacts on minority and/or lowincome communities, as none have been identified within the study area per 2000

U.S. Census information and requirements of Executive Order (E.O.) 12898.

Increasing populations worldwide. Increasing opportunity for the development of

minority communities and the expansion of low-income populations worldwide.

5.15.4.2 Alternative 33 (Recommended Plan)

Direct. No direct impacts on human health or environmental effects within

the study area would occur with the implementation of Alternative 33

(Recommended Plan).

Indirect. No indirect impacts on human health or environmental effects

within the study area would occur with the implementation of Alternative 33

(Recommended Plan).

Cumulative. There would be no adverse cumulative impacts on minority

and/or low-income communities as none have been identified within the study area

per 2000 U.S. Census information and requirements of E.O. 12898. Environmental

justice issues are unlikely to occur when combined with other Federal, state, local,

and private restoration efforts.

5.15.4.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.5 Infrastructure

5.15.5.1 No-Action Alternative

Direct. There would be no direct impacts to infrastructure.

Indirect. Existing and future infrastructure present within the study area

would be indirectly affected due to the land loss created from the deterioration and

conversion of existing swamp habitat to shallow open water habitat.

Cumulative. Cumulative effects would continue as land loss would increase

erosion on infrastructure, similar to impacts from wetland loss and degradation

throughout coastal Louisiana. Conversion of swamp vegetation to fresh marsh or

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open water habitat may affect relocations and maintenance of infrastructure within

the study area.

5.15.5.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct effect on infrastructure.

Indirect. Existing and future infrastructure present within the study area

would be indirectly benefitted. Restoration and preservation of the swamp system

would support the sustainability of existing infrastructure by reducing inundation,

wave action, and erosion.

Cumulative. Cumulative impacts would be the beneficial effects of

restoration which supports infrastructure with other coastal restoration protection

projects. This alternative would have positive effects on infrastructure when

combined with other Federal, state, local, and private restoration efforts (see

Figure 5.1 and Table 5.2). There would be a reduced level of infrastructure damages

and relocations compared to the No-Action Alternative.

5.15.5.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33 (Recommended

Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.6 Business and Industry

5.15.6.1 No-Action Alternative

Direct. There would be no direct impacts on business and industry.

Indirect. There would be no indirect impacts to business and industry.

Cumulative. Continued population growth and supporting business and

industry development contributes to degradation and loss of coastal and other

wetlands. Degradation and loss of wetlands would contribute to potential losses of

businesses.

5.15.6.2 Alternative 33 (Recommended Plan)

Direct. There would be minor direct benefits due to the temporary jobs and

services required for the construction and monitoring of Alternative 33

(Recommended Plan).

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Indirect. There would be minor indirect benefits related to the continued

support of business and industry by reducing the degradation and loss of wetlands

that could contribute to the potential losses of businesses.

Cumulative. Cumulative impacts would continue to be controlled primarily

by the national and regional economy. This alternative would have little effects on

business and industry when combined with other Federal, state, local, and private

restoration efforts (see Figure 5.1 and Table 5.2). The study area does not appear to

provide many opportunities for future business growth.

5.15.6.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.7 Traffic and Transportation

5.15.7.1 No-Action Alternative

Direct. There would be no direct impacts to traffic and transportation,

including highways or golf cart paths within the study area.

Indirect. Wetland land loss threatens the stability of roads passing through

the area, resulting in increased maintenance.

Cumulative. Wetland land loss threatens the stability of roads passing

through the area, resulting in increased maintenance. Assuming existing permitted

projects are completed, several of the current subdivisions would expand, creating

additional roads, bridges, and traffic.

5.15.7.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts on traffic and transportation.

Indirect. This alternative would have little effect on traffic and

transportation. There would be a reduced level of road damages and relocations due

to wetland loss.

Cumulative. This alternative would have little effect on traffic and

transportation when combined with other Federal, state, local, and private

restoration efforts (see Figure 5.1 and Table 5.2). There would be a reduced level of

road damages and relocations due to wetland loss.

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5.15.7.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.8 Public Facilities and Services

5.15.8.1 No-Action Alternative

Direct. There would be no direct impacts on public facilities and services,

such as sewerage, wastewater treatment, or electrical facilities.

Indirect. Wetland land loss potentially threatens public facilities and

services and increases maintenance.

Cumulative. Wetland land loss potentially threatens public facilities and

services and increases maintenance. Several of the current subdivisions would

expand, creating additional needs for public facilities and services.

5.15.8.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts on public facilities and services.

Indirect. This alternative would have little effect on public facilities and

services. There would be a reduced level of damages and relocations of public

facilities and services and increased maintenance due to wetland loss.

Cumulative. This alternative would have little effect on public facilities and

services when combined with other Federal, state, local, and private restoration

efforts (see Figure 5.1 and Table 5.2). There would be a reduced level of public

facilities and services damages and relocations due to wetland loss.

5.15.8.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

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5.15.9 Local Government Finance

5.15.9.1 No-Action Alternative

Direct. There would be no direct impacts on local government finance, since

there are no incorporated towns within the study area.

Indirect. Increasing population growth would increase the funding for local

government.

Cumulative. There is no potential for new town development, and none

would be developed in the future. Expansion of the current subdivisions would

increase the tax base, thus increasing local government finances.

5.15.9.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts on local government finance.

Indirect. There would be no indirect impacts on local government finance.

Cumulative. Cumulative impacts would continue as controlled by the local

population. This alternative would have little effect on local government finances

when combined with other Federal, state, local, and private restoration efforts (see

Figure 5.1 and Table 5.2). There is no potential for new town development within or

contiguous to the area impacted by this alternative, and none would be developed in

the future. Expansion of the current subdivisions would increase the tax base, thus

increasing local government finances.

5.15.9.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.10 Tax Revenue and Property Values

5.15.10.1 No-Action Alternative

Direct. There would be no direct impacts on tax revenue and property

values.

Indirect. Additional increases in property values and tax revenues would be

sustained through the filling of lots in the existing and proposed subdivisions. At

the same time, property values may drop from lowering aesthetics due to swamp

degradation.

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Cumulative. Cumulative impacts would continue as controlled by the local

population growth and tax base.

5.15.10.2 Alternative 33 (Recommended Plan)

Direct. There would be minor direct increases in tax revenue due to the

goods and services required for the construction and monitoring associated with the

implementation of Alternative 33 (Recommended Plan). There would be little to no

direct effects on overall property values within the study area.

Indirect. Additional increases in property values and tax revenues would

be sustained through the filling of lots in the existing and proposed subdivisions as

well as due to increased aesthetics. Minor indirect increases in tax revenue due to

the goods and services associated with the construction of Alternative 33

(Recommended Plan) and the preservation and improvement due to the project.

Cumulative. Cumulative effects would continue as controlled by the

national and regional economy. This alternative would have little effect on tax

revenue and property values when combined with other Federal, state, local, and

private restoration efforts (see Figure 5.1 and Table 5.2). Additional increases in

property values and tax revenues would be sustained through the filling of lots in

the existing and proposed subdivisions as well as due to increased aesthetics.

5.15.10.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.11 Community and Regional Growth

5.15.11.1 No-Action Alternative

Direct. There would be no direct impacts on community and regional

growth.

Indirect. There would be little indirect impacts on community and regional

growth. Little additional infilling would occur in Berthelot’s Campground,

Waterfront East, and Three Rivers Island since those communities are nearly fully

developed or fully inhabited. Assuming the existing permitted projects are

constructed, additional growth would occur with the extension of the Three Rivers

Island campsites to the east and the establishment of Waterfront East-Sanctuary

South. These projects would continue to contribute to the growth of the southern

portion of Livingston Parish. After these developments are completed, the

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possibilities of the study area would have been largely exhausted because of the

lack of developable land.

Cumulative. Minor additional increases in community and regional growth

would be sustained through the infilling of lots in the existing and proposed

subdivisions. Cumulative effects would continue to be controlled by the national,

regional, and local economy.

5.15.11.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts on community and regional growth

due to the implementation of Alternative 33 (Recommended Plan).

Indirect. There would be little indirect impacts on community and regional

growth due to the implementation of Alternative 33 (Recommended Plan). Little

additional infilling would occur in Berthelot’s Campground, Waterfront East, and

Three Rivers Island since those communities are nearly fully developed or fully

inhabited. Assuming the existing permitted projects are constructed, additional

growth would occur with the extension of the Three Rivers Island campsites to the

east and the establishment of Waterfront East-Sanctuary South. These projects

would continue to contribute to the growth of the southern portion of Livingston

Parish. After these developments are completed, the possibilities of the study area

would have been largely exhausted because of the lack of developable land.

Cumulative. This alternative would have little effect on community and

regional growth when combined with other Federal, state, local, and private

restoration efforts (see Figure 5.1 and Table 5.2). Additional increases in

community and regional growth would be sustained through the filling of lots in the

existing and proposed subdivisions.

5.15.11.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.12 Land Use Socioeconomics

5.15.12.1 Agriculture

5.15.12.1.1 No-Action Alternative

Direct. There would be no direct impacts to agriculture or pasture

acreage since no such acreage is present within the study area.

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Indirect. There would be no indirect impacts to agriculture or

pasture acreage.

Cumulative. Cumulative effects on agriculture would continue to be

controlled by the national, regional, and local economy. Agricultural lands,

primarily livestock pastures, within the study area would continue to be used and

may be adversely impacted by habitat conversion and land loss.

5.15.12.1.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts to agriculture or pasture

acreage since no such acreage is present within the study area.

Indirect. There would be no indirect impacts to agriculture or

pasture acreage.

Cumulative. This alternative would have positive effects on

agriculture when combined with other Federal, state, local, and private restoration

efforts (see Figure 5.1 and Table 5.2). There would be a reduced level of agriculture

land habitat conversion and land loss compared to the No-Action Alternative.

5.15.12.1.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33

(Recommended Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.12.2 Forestry

5.15.12.2.1 No-Action Alternative

Direct. There would be no direct effects to forestry, including timber

harvesting.

Indirect. There would be continued degradation in the quality and

quantity of the trees within the study area and vicinity, greatly reducing the

potential for forestry activities, such as timber harvesting. It is anticipated that

timber resources within the study area would not reach merchantable size over the

50-year period of analysis. Existing tree stands would not be regenerated because

of continued substrate degradation.

Cumulative. Cumulative impacts would be additive to the impacts

from wetland loss and degradation throughout coastal Louisiana. Other cumulative

impacts include the conversion of 18,204 acres of swamp to a shallow open water

system within the study area, which would be additive with other swamp losses and

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degradation impacts to forestry throughout the region and state (see Figure 5.1 and

Table 5.2).

5.15.12.2.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts to forestry, including timber

harvesting.

Indirect. Channel Improvement, Flowage and Deposition, and

Wetland Creation and Restoration easements would be placed within the primary

and secondary areas of impact for Alternative 33 (Recommended Plan), effectively

restricting timber harvesting within portions of the study area over an indefinite

period of time. Therefore this alternative would have negative impacts on timber

harvesting within portions of the study area. The Real Estate Plan in Appendix J

provides descriptions of the easements which will be placed within the areas of

impact.

Cumulative. This alternative would have negative additive effects on

timber harvesting. Timber harvesting would be very limited, if not completely

reduced, in the benefit areas. Cumulative impacts would be additive to other

impacts to forestry throughout the region and state

5.15.12.2.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33

(Recommended Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.12.3 Public Lands

5.15.12.3.1 No-Action Alternative

Direct. There would be no direct impacts to public lands, such as

Maurepas Swamp Wildlife Management Area (WMA).

Indirect. Adverse indirect impacts could occur to nearby public lands

as a result of swamp degradation and conversion to fresh marsh and open water.

Impacts could also result from the consequent loss of storm damage benefits

currently provided by the existing nearby swamp habitat. A portion of the

Maurepas WMA is the only public lands present in the study area.

Cumulative. Cumulative impacts would be additive to the wetland

loss and degradation throughout coastal Louisiana. A portion of the Maurepas

Wildlife Management Area (WMA) is the only public lands present within the study

area. These lands may be adversely affected by future sea level rise and continued

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habitat conversion and land loss. Other cumulative impacts include the conversion

of 18,204 acres of swamp to a shallow open water system within the study area,

which would be additive with other swamp losses and degradation impacts to public

lands throughout the region and state (see Figure 5.1 and Table 5.2).

5.15.12.3.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts to public lands, such as

Maurepas Swamp Wildlife Management Area since Alternative 33 (Recommended

Plan) project components are not located or being implemented near or within the

WMA.

Indirect. There would be minor beneficial indirect impacts by

restoring the swamp adjacent to the public lands because the forested habitat

within the project footprint will provide storm surge and windfall protection to

nearby public lands.

Cumulative. Cumulative impacts would be additive to the wetland

loss and degradation throughout coastal Louisiana. A portion of the Maurepas

WMA is the only public lands present within the study area. These lands may be

adversely affected by future sea level rise and continued habitat conversion and

land loss. Other cumulative impacts include the conversion of 18,204 acres of

swamp to a shallow open water system within the study area, which would be

additive with other swamp losses and degradation impacts to public lands

throughout the region and state (see Figure 5.1 and Table 5.2).

5.15.12.3.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33

(Recommended Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.13 Navigation

5.15.13.1 No-Action Alternative

Direct. There would be no direct impacts to navigation, commercially since

there is little commercial fisheries within the study area, or recreationally.

Indirect. The degradation and loss of wetlands contribute to increased

maintenance costs of navigation infrastructure.

Cumulative. Cumulative impacts include the conversion of 18,204 acres of

swamp to a shallow open water system within the study area. As Louisiana's

coastal wetlands continue to fragment and convert to open water, the protection

wetlands provide to inland waterways from wind-driven waves would likely be

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reduced. Amite River and Bayou Manchac Federal navigation channel and AR&T

flood control channel are likely to continue to be used primarily for recreational

navigation. Inland vessels, such as barge traffic, would be subjected to more open

water marine-like conditions.

5.15.13.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts to navigation, commercially or

recreationally.

Indirect. Beneficial indirect impacts could occur as a result of wetland

restoration, such as the sustainability of portions of the ARDC and other navigation

channels in the area.

Cumulative. This alternative would have positive effects on navigation

when combined with other Federal, state, local, and private restoration efforts (see

Figure 5.1 and Table 5.2). Cumulative impacts would be the protection of navigation

channels.

5.15.13.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.14 Man-Made Resources

5.15.14.1 Oil, Gas, Utilities and Pipelines

5.15.14.1.1 No-Action Alternative

Direct. There would be no direct impacts to oil and gas utilities or

pipelines as a result of the No-Action alternative.

Indirect. Wetland land loss increases the vulnerability of pipelines

and other infrastructure.

Cumulative. Increasing O&M costs as well as increasing investment

in oil and gas production facilities and pipelines, increasing vulnerability of

pipelines and other infrastructure due to widespread coastal wetland loss. Wells are

likely to remain and active pipelines likely to be present.

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

at this time. 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

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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. 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 22, 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.

• 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

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.

5.15.14.1.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct beneficial or adverse impacts to oil

and gas utilities or pipelines.

Indirect. There would be no indirect beneficial or adverse impacts to

oil and gas utilities or pipelines.

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Cumulative. This alternative would have positive effects on the

protection of oil, gas, utilities, and pipelines when combined with other Federal,

state, local, and private restoration efforts (see Figure 5.1 and Table 5.2). These

facilities would be less susceptible to storm surges and other damage due to wetland

loss.

5.15.14.1.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33

(Recommended Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.14.2 Flood Control and Hurricane Protection

5.15.14.2.1 No-Action Alternative

Direct. There would be no direct impacts to flood control, such as the

ARDC or the Chinaquapin Canal, or hurricane protection levee projects since there

are none located within the study area.

Indirect. There would be a continued degradation of forested habitat

within the study area, which provides valuable storm-surge and windfall protection

from tropical storms. Therefore, there could be an increase in storm surge and risk

of flooding due to coastal land loss. As populations continue to migrate to coastal

communities, increasing investments in hurricane and flood control levees, pump

stations, and other flood control facilities would be required.

Cumulative. Cumulative impacts would be increased flood damages

from hurricane events, and land loss and degradation throughout coastal Louisiana.

Other cumulative impacts include the conversion of 18,204 acres of swamp to a

shallow open water system within the study area, which would be additive with

other swamp losses and degradation impacts to flood control and hurricane

protection throughout the region and state. However, the negative impacts of

wetland loss to flood control and hurricane protection within the study area and

vicinity would be offset to some extent by other Federal, state, local, and private

restoration efforts across coastal Louisiana, including the West Lake Shore

Pontchartrain Hurricane Protection Project (see Figure 5.1 and Table 5.2).

5.15.14.2.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts to flood control and

hurricane protection levee projects. Implementation of Alternative 33

(Recommended Plan) would have an insignificant reduction in the stage on the

Amite River and on the ARDC. As a result, there would not be an increased risk of

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flooding for nearby businesses and residences. An insignificant increase in stage

height within the swamp area, near the proposed openings in the ARDC dredged

material berms, would occur. There are no hurricane protection levee projects

within the study area; therefore, there will be no direct impacts to hurricane

protection projects.

Indirect. There would be a restoration of forested habitat within the

study area, which provides valuable storm surge and windfall protection from

tropical cyclone events. Consequently, there could be an increase in storm surge

protection and decrease in flooding risk with coastal land retention. As populations

continue to migrate to coastal communities, increasing investments in hurricane

and flood control levees, pump stations, and other flood control facilities would be

required.

Cumulative. This alternative would have a positive additive effect on

hurricane protection. The proposed action would nourish existing swamp habitat

and create swamp habitat that is currently converting and has converted to open

water. The reduction of conversion of swamp to open water would provide for some

protection from storm surges and wave action. Cumulative impacts include the

increased sustainability of portions of the ARDC, a flood control channel. The

impacts to flood control and hurricane protection levee projects within the study

area and vicinity would be additive to some extent with other Federal, state, local,

and private restoration efforts across coastal Louisiana, including the West Lake

Shore Pontchartrain Hurricane Protection Project (see Figure 5.1 and Table 5.2).

5.15.14.2.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33

(Recommended Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.15.15 Natural Resources

5.15.15.1 Commercial Fisheries

5.15.15.1.1 No-Action Alternative

Direct. There would be no direct impacts on commercial fisheries,

including catfish harvesting within the Blind River or Petite Amite River. There

are no oyster leases within the study area; therefore, no direct impacts would occur.

Indirect. Indirect impacts would result in the persistence of existing

conditions including the continued conversion of existing wetlands to open water

habitat, continued bankline erosion, and sloughing of the existing shoreline.

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Cumulative. Cumulative impacts would be the continued effects on

commercial fisheries from wetland loss and degradation throughout coastal

Louisiana. Globally, overfishing and habitat change has resulted in the depletion of

90 percent of the world’s seafood resources, with 38 percent of the species studied

experiencing greater than 90 percent depletion, and 7 percent becoming extinct

(Worm et al., 2006). This trend is expected to continue under the No-Action

Alternative. Throughout Louisiana and the study area, the loss of commercial

fishery habitat due to the loss of essential wetland habitat and salinity changes is

likely to occur. Other cumulative impacts include the conversion of 18,204 acres of

swamp to a shallow open water system within the study area, which would be

additive with other swamp losses and degradation impacts to commercial fisheries

throughout the region and state. The positive impacts of restoration to commercial

fisheries within the study area and vicinity would be additive to some extent with

other Federal, state, local, and private restoration efforts across coastal Louisiana

(see Figure 5.1 and Table 5.2).

5.15.15.1.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impact on commercial fisheries,

including catfish harvesting within the Blind River or Petite Amite River. There

are no oysters within the study area; therefore, no direct impacts would occur.

Indirect. Wetland restoration would indirectly create and restore

fisheries habitat. This would support populations of fishery species and enhance

commercial fishing opportunities, including catfish harvesting and crabbing, within

the study area and vicinity.

Cumulative. Habitat loss for commercial fisheries would continue

due to the land loss and wetland deterioration in coastal Louisiana. A net total of

1,602 acres of swamp habitat would be restored and nourished. The positive

impacts of restoration to commercial fisheries within the study area and vicinity

would be additive to some extent with other Federal, state, local, and private

restoration efforts across coastal Louisiana (see Figure 5.1 and Table 5.2).

5.15.15.1.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33

(Recommended Plan).

Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan).

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

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5.16 HAZARDOUS, TOXIC, AND RADIOACTIVE WASTE

The Phase I Environmental Site Assessment (ESA) for the study area

identified two Recognized Environmental Concerns (RECs) that may have adversely

impacted, or may potentially impact, environmental conditions in the study area:

Underground Storage Tanks (USTs) at the former Chinquapin Grocery, and

Aboveground Storage Tanks (ASTs) at Val’s Marina. Although there are no records

in the LDEQ’s database regarding leaks from the two RECs, no soil and/or

groundwater samples were collected to confirm that leaks did or did not occur.

There is no visible evidence of spills or leaks in the vicinity of the RECs. Although

located within the study area boundaries, neither of the two identified RECs are in

close proximity to the portions of the study area projected to be impacted by the

implementation of any of the final array of alternatives under consideration.

Therefore, neither of the RECs located within the study area would likely expose

the public or construction workers to HTRW or to adversely affect the project. If the

project area changes, however, then additional investigation may be necessary. The

HTRW report is provided in Appendix M.

5.16.1 No-Action Alternative

Direct. There would be no direct impacts to HTRW.

Indirect. There would be no indirect impacts to HTRW.

Cumulative. Within the study area, increasing human populations and

industrialization are likely to result in increased potential for HTRW problems.

5.16.2 Alternative 33 (Recommended Plan)

Direct. There would be no direct impacts to HTRW since neither REC is in

close proximity to the portions of the study area projected to be impacted by the

implementation of Alternative 33 (Recommended Plan).

Indirect. There would be no indirect impacts to HTRW since neither REC is

in close proximity to the portions of the study area projected to be impacted by the

implementation of Alternative 33 (Recommended Plan).

Cumulative. There would be no cumulative impacts on HTRW. HTRW

issues are unlikely to occur when combined with other Federal, state, local, and

private restoration efforts (see Figure 5.1 and Table 5.2).

5.16.3 Alternatives 34-39

Direct. Direct impacts would be similar to Alternative 33 (Recommended

Plan) since neither REC is in close proximity to the portions of the study area

projected to be impacted by the implementation of any of the final array of

alternatives under consideration.

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Indirect. Indirect impacts would be similar to Alternative 33

(Recommended Plan) since neither REC is in close proximity to the portions of the

study area projected to be impacted by the implementation of any of the final array

of alternatives under consideration.

Cumulative. Cumulative impacts would be similar to Alternative 33

(Recommended Plan).

5.17 UNAVOIDABLE ADVERSE IMPACTS

The unavoidable adverse impacts resulting from implementation of any one of the

seven proposed actions within the final array of alternatives would be the

temporary impacts associated with construction, such as the loss of some trees

within the project footprint, noise impacts due to the operation of large equipment,

and the initial loss of some habitat during the clearing phase of the construction

process. All of these impacts are considered temporary and have no impact on the

long-term environmental impacts resulting from the proposed actions.

5.18 RELATIONSHIP OF SHORT-TERM USES AND

LONG-TERM PRODUCTIVITY

All seven proposed actions within the final array of alternatives, including the

Recommended Plan would increase the long-term productivity of healthy freshwater

swamp regeneration within the study area. Added hydrologic connectivity and

reductions in impoundment would play a critical role in supplying the swamp

habitat with nutrient and sediments on a seasonal basis. The addition of vegetative

plantings would also serve as a means of initiating the regeneration and

germination of cypress/tupelo swamp habitat within the most highly-degraded

areas.

5.19 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF

RESOURCES

Of all seven proposed actions within the final array of alternatives, excluding the

No-Action Alternative, the irreversible and irretrievable commitments of resources

would include the opening of the dredged material berms and the loss of existing

vegetative resources during construction. All of these commitments would result in

increased benefits for the study area and therefore, would not be viewed as a longterm negative impact.

5.20 MITIGATION

All seven alternatives, including the Recommended Plan, would generate a net gain

in benefits; therefore, no mitigation would be required for implementation and

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construction of this proposed action. The Recommended Plan would result in a net

gain of 679 AAHUs.

5.21 ENVIRONMENTAL CONSEQUENCES SUMMARY

The continued swamp degradation and conversion to marsh and open water leads to

increased competition between wetland-dependent wildlife populations,

displacement to other more suitable swamp wetland areas, and localized decline in

wildlife populations. The loss of forest canopy would select against many species,

such as neotropical migrants and nesting birds. The conversion to open water

would select against small and large mammals, but may offer some more habitat for

dabbling ducks.

The overall effect of all proposed actions within the final array of alternatives,

excluding the No-Action Alternative, would be a net increase in benefits for the

environmental resources within the study area with little to no negative impacts.

The Recommended Plan would create a net gain of 679 AAHUs for the areas of

impact. The No-Action Alternative would result in the continued degradation of the

cypress/tupelo swamp habitat along with the wildlife and aquatic resources within

the study area. The long-term effects of no Federal action would be the eventual

conversion of thousands of acres of freshwater swamp to open water within the next

50 years.

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6.0 PUBLIC INVOLVEMENT

6.1 NEPA SCOPING

A Notice of Intent (NOI) to prepare a Draft Supplemental EIS (DSEIS) for the LCA

ARDC Modification Feasibility Study was published on December 22, 2008 in the

Federal Register (Volume 73, Number 246). It was subsequently determined that

an SEIS would be included in an Integrated Feasibility Report as a supplement to

the 2004 LCA ARDC report.

The public scoping meeting was held on February 12, 2009, in French Settlement,

Louisiana. A total of 30 multi-part comments were received during the comment

period. A total of 86 specific comments were expressed. The comments received

were incorporated into the planning formulation process in the identification of

goals, objectives, study area problems and the management measures considered.

Comments were evaluated for recurring themes to gain an understanding of the key

issues to address in the SEIS. Primary concerns uncovered in the comments were:

• Weir at French Settlement does not function properly and diverts excessive

flow to ARDC, impairing lower Amite River.

• Project should incorporate weir construction at downstream end of ARDC.

• ARDC construction has disrupted natural hydrologic regime and damaged

properties.

• Endangered/protected species are present in the study area and vicinity.

• Scope of project should address wildlife and fisheries habitat.

• Hydrology and Hydraulics modeling should be expansive, incorporate

conditions from other projects, and/or involve stage data collection.

The scoping comments were documented in a Scoping Report and describe the

public's concerns about the restoration effort and strategies for restoration efforts.

All registered scoping meeting participants, as well as those providing written or

verbal comments, were provided a copy of the Scoping Report. In addition, the

Scoping Report was posted on the study website at http://www.lca.gov. Scoping

comments received to date are summarized in Tables 6.1 and 6.2. All public

comments received on the draft FS/SEIS are summarized in Appendix G.

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Table 6.1. Public Scoping Comment Themes

by Percentages of Occurrence

Ranking Theme Number of

Comments

Percent

Occurrence

1

Weir at French Settlement does not function

properly and diverts excessive flow to ARDC,

impairing lower Amite River.

10 12.2%

2 Project should incorporate weir construction at

downstream end of ARDC. 7 8.5%

3 ARDC construction has disrupted natural

hydrologic regime and damaged properties. 6 7.3%

4 Endangered/protected species are present in the

study area and vicinity. 6 7.3%

5 Scope of project should address wildlife and

fisheries habitat. 6 7.3%

6

H&H modeling should be expansive, incorporate

conditions from other projects, and/or involve stage

data collection.

6 7.3%

7 Project should incorporate rehabilitation of weir at

French Settlement. 5 6.1%

8 Southwestern boundary of study area should be

expanded. 5 6.1%

9 Boat trips to reconnaissance study area are

needed. 4 4.9%

10 Diversion canal stages are primarily influenced by

Lake Maurepas. 4 4.9%

11 Gap placement is an issue because of development

on dredged material berms. 4 4.9%

12 Swamps south of Bayou Pierre are impaired from

acidity caused by lack of hydrologic exchange. 3 3.7%

13 Project is greatly needed and should be completed

on an expedited schedule. 3 3.7%

14 Project should include vegetative planting or

nature control. 3 3.7%

15 Create hydrologic exchange between Bayou Pierre

and ARDC on south canal bank. 2 2.4%

16 Colonial nesting waterbird rookeries are present in

the study area. 2 2.4%

17 Draining swamp waters may impair water quality

in ARDC and downstream. 2 2.4%

18 Project should operate under flood events, not

merely normal flow or high flow conditions. 1 1.2%

19

Dredged material berm gapping has been

implemented as part of waterfront development

projects in study area.

1 1.2%

20 Avoidance or minimization of forest habitat

impacts should be considered during gap location. 1 1.2%

21 Project scope should include restoration of lower

Amite River 1 1.2%

Total: 82 100%

Note: The number of occurrences totals 82 because a given comment can be associated with more than one theme. The

percentages are based on dividing the number of occurrences of a given theme by the total number of occurrences and

multiplying by 100.

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Table 6.2. Public Scoping Comments Considered

Rank Theme Comment Incorporation or

Consideration

1

Weir at French Settlement does not

function properly and diverts excessive

flow to ARDC, impairing lower Amite

River.

Weir rehabilitation was considered as a

measure in Section 3 of this study (WR-01).

While we recognize that rehabilitation to the

weir might be necessary, it was determined

that the performance of the weir would have

little to no effect to restoring the degraded

portions of the study area. During the

preliminary phases of the plan formulation

process, rehabilitation of the weir was

considered and subsequently screened out due

to a lack of restoration opportunities this

measure would provide.

2

Project should incorporate weir

construction at downstream end of

ARDC.

Weirs were considered as potential measures,

but were screened out. This process is

described in detail in Section 3 of the report

(WC-01 through WC-08).

3

ARDC construction has disrupted

natural hydrologic regime and damaged

properties.

The objective of this project is to restore

hydrologic connectivity to the area.

4 Endangered/protected species are

present in the study area and vicinity.

Environmental consequences are discussed in

detail in Section 5 of this report.

5 Scope of project should address wildlife

and fisheries habitat.

Environmental consequences are discussed in

detail in Section 5 of this report.

6

H&H modeling should be expansive,

incorporate conditions from other

projects, and/or involve stage data

collection.

The LCA Blind River/Hope Canal Diversion

projects were considered in the Hydrology and

Hydraulics analysis, and the study area

chosen was considered adequate for the

purposes of the analysis needed. The H&H

analysis is included in Appendix L, Section 2.

7 Project should incorporate rehabilitation

of weir at French Settlement.

Rehabilitation does not efficiently contribute

to the accomplishment of the goals for this

project. This was considered as a measure in

section 3 of this study (WR-01)

8 Southwestern boundary of study area

should be expanded.

The study area subunit SW-2 was expanded to

cover additional area to the south and west of

the outline proposed during the public scoping

meeting.

9 Boat trips to reconnaissance study area

are needed. Several reconnaissance boat trips were made.

10 Diversion canal stages are primarily

influenced by Lake Maurepas. Modeling shows that this is true.

11 Gap placement is an issue because of

development on dredged material berms.

This was considered as a part of the project,

and it was determined that the maximum

benefit could be achieved without locating the

gaps in developed areas.

12 Swamps south of Bayou Pierre are

impaired from acidity caused by lack of

Measures describing consideration given to

Bayou Pierre are described in Section 3 (BO383
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Rank Theme Comment Incorporation or

Consideration

hydrologic exchange. 01, BO-02, CD-02, CS-02, CS-03, CS-04, SR02)

13 Project is greatly needed and should be

completed on an expedited schedule. We concur.

14

Project should include vegetative

planting or nature control.

These measures are included as a part of the

Recommended Plan and are described in

Section 3 (VP-01, VP-02).

15

Create hydrologic exchange between

Bayou Pierre and ARDC on south canal

bank.

Measures describing consideration given to

Bayou Pierre are described in Section 3 (BO01, BO-02, CD-02, CS-02, CS-03, CS-04, SR02)

16 Colonial nesting waterbird rookeries are

present in the study area.

Environmental consequences are discussed in

detail in Section 5 of this report.

17 Draining swamp waters may impair

water quality in ARDC and downstream.

No long-term water quality impacts are

expected downstream of this project. Water

quality impacts are discussed in detail in

Section 5.3 of this report.

18

Project should operate under flood

events, not merely normal flow or high

flow conditions.

Design will operate in said conditions.

19

Dredged material berm gapping has been

implemented as part of waterfront

development projects in study area.

Analysis was conducted including existing

gaps as a part of this study, and the

recommended plan of action was to create

larger gaps to increase hydrologic

connectivity.

20

Avoidance or minimization of forest

habitat impacts should be considered

during gap location.

The alternatives were chosen based on the

maximum net benefit possible, therefore

minimization of impacts was considered.

21 Project scope should include restoration

of lower Amite River

Lower Amite River is outside the scope of the

project and will not be included.

6.2 OTHER PUBLIC COMMENTS, AREAS OF CONTROVERSY,

UNRESOLVED ISSUES

The following meetings were held to provide opportunities for the public,

landowners, NGOs, agencies, the Parishes and other interested parties to see

progress on the project and to solicit feedback from the attendees.

• Livingston Parish - August 6, 2008

• Ascension Parish - July 30, 2008

• Public Scoping Meeting - February 12, 2009

• Louisiana Department of Wildlife and Fisheries - June 15, 2009

• LCA Science Board Presentation - July 16, 2009

• Livingston Parish- August 6, 2009

• Ascension Parish- August 6, 2009

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• Landowner - August 31, 2009

• Conservation Fund - November 2, 2009

• Conservation Fund - February 4, 2010

• Conservation Fund - February 9, 2010

• Livingston Parish- February 23, 2010

• Public Feasibility Scoping Meeting - June 24, 2010

6.2.1 Land Owner Involvement

Mr. Glen Martin, part owner of Blind River Properties Inc. and majority land owner

within the ADRC study area, has been granted a permit to develop the southern

bank of the ARDC in a manner similar to the development constructed on the

northern shore. Several meetings have been held with Mr. Martin in which

proposed project alternatives were presented. Mr. Martin supports restoration in

the study area.

6.2.2 Non-Governmental Organization (NGO) Involvement

Both the Lake Pontchartrain Basin Foundation and the Coalition to Restore

Coastal Louisiana provided support and suggestions about the ARDC modification

project through a joint letter dated February 20th, 2009 to the commander of the

New Orleans office of the USACE. On November 2, 2009, February 4, 2010 and

February 9, 2010, meetings were held with the Louisiana Conservation Fund (LCF)

along with the Audubon Society to collaborate future LCA ARDC efforts with LCF

goals.

6.2.3 Parish Involvement

The study area for the LCA ARDC modification project is located within Ascension

and Livingston Parishes. Separate meetings were held between representatives of

Ascension and Livingston Parish, in order to solicit feedback on the project

objectives and to report on the progress to date. Continual coordination between

the LCA ARDC Project Delivery Team (PDT) and Parish representatives has

occurred, Additional meetings have been held with Livingston Parish to prepare for

the potential coordination between the Hydrologic Restoration in Swamps West of

Lake Maurepas CIAP and the LCA ARDC projects.

6.3 PUBLIC COMMENTS ON THE DSEIS

The Integrated Feasibility Report and Supplemental Environmental Impact Study

(SEIS) was released to the public on May 21, 2010, and was followed by a 45-day

public review period ending on July 6, 2010. Additionally, a public meeting was

held on June 24, 2010 in French Settlement Louisiana. Comments received and the

responses to them are included in Appendix G.

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7.0 COORDINATION AND COMPLIANCE

7.1 U. S. ARMY CORPS OF ENGINEERS (USACE) PRINCIPLES AND

GUIDELINES (P&G)

This section documents the coordination and compliance efforts regarding statutory

authorities including: environmental laws, regulations, executive orders, policies,

rules, and guidance. Consistency of the TSP/Recommended Plan with other

Louisiana coastal restoration efforts is also described.

7.2 ENVIRONMENTAL COORDINATION AND COMPLIANCE

Following completion of the Supplemental Environmental Impact Study (SEIS), 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 of the SEIS. Relevant State of Louisiana statutory

authorities are listed in Table 7.2 of the SEIS. Full compliance with statutory

authorities will be accomplished upon review of the Final Feasibility Report and

SEIS by appropriate agencies and the signing of a ROD, in compliance with the

Fish and Wildlife Coordination Act (1958).

If a proposed project feature within the Recommended Plan is changed significantly

or is not implemented within one year of the USFWS Final Coordination Act

Report, the USACE will reinitiate coordination with the USFWS to insure that the

proposed action would not adversely affect any Federally-listed threatened or

endangered species or their critical habitat. Additionally, all further detailed

planning of project features (e.g., Design Documentation Report, Engineering

Documentation Report, Plans and Specifications, or other similar documentation)

will be coordinated with the USFWS and other state and Federal natural resource

agencies, and those agencies would be provided an opportunity to review and

submit recommendations on all the work addressed in those reports.

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

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

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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-toKnow

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

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

Title VI, Section 601 of the Civil Rights Act of 1964

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

Louisiana Threatened and Endangered Species

and Rare & Unique Habitats

Protection of Cypress Trees

Water Control Act

7.2.1 Clean Water Act – Section 404(b)(1)

The USACE is responsible for administering regulations under Section 404(b)(1) of

the Clean Water Act. Potential project-related impacts subject to these regulations,

such as the discharge of dredged material into shallow open water areas to create

wetlands have been evaluated in compliance with Section 404(b)(1) of the Clean

Water Act (Appendix D). All relevant Federal and state authorities and Executive

Orders are found in Tables 7.1 and 7.2. 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 requirement of these

guidelines, with the inclusion of appropriate and practicable methods to minimize

adverse effects to the aquatic ecosystem. Water Quality Certification was received

on September 20, 2010 and is included in Appendix D.

7.2.2 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, aesthetic

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; and

Disruption of desirable community and regional growth.

7.2.3 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, to

assure that those activities or projects are consistent, to the maximum extent

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practicable, with the approved state coastal zone management program. A Coastal

Zone Consistency Determination will be included with this report has been

submitted to Louisiana Department of Natural Resources (LDNR) for consistency

review. A Consistency Determination received on August 9, 2010 and is included in

Appendix E. Implementation of the Recommended Plan is considered consistent, to

the maximum extent practicable, with the approved Louisiana state coastal

management program.

7.2.4 Endangered Species Act of 1973

Compliance with the Endangered Species Act (ESA) (7 U.S.C. 136; 16 U.S.C. 460

et seq.) has been coordinated with the USFWS and the NMFS for those species

under their respective jurisdictions. The use of recommended primary activity

exclusion zones and timing restrictions would be utilized, to the maximum extent

practicable, to avoid project construction impacts to any threatened or endangered

species or their critical habitat within the proposed action area. The USACE would

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. Although Gulf sturgeon and West

Indian manatee may be Recommended Plan to these species are unlikely (see also

Section 5.11 Threatened and Endangered Species). A Biological Assessment is

included in this report (Appendix A). Comments and concurrence from the USFWS

on the proposed action are included in Appendix G.

7.2.5 Magnuson-Stevens Fishery Conservation and Management Act of

1996; and the Magnuson-Stevens Act Reauthorization of 2006 Essential

Fish Habitat (EFH)

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. NMFS indicated that the

study area may contain some habitat for euryhaline species such as Gulf menhaden

and striped mullet, but that EFH is not present within the study area (see also

Section 5.10 EFH).

7.2.6 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 Louisiana Department of Environmental Quality

(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 Recommended Plan. 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

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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. Therefore, the air applicability determination analysis

was based upon direct emission for estimated construction hours. Considering that

total emissions for each work item separately (or even when all work items are

summed) would not exceed the threshold limit applicable to VOCs for parishes

where the most stringent requirement (50 tons per year in serious non-attainment

parishes) is in effect, (see General Conformity, State Implementation Plan, Section

1405 B.2), the Volatile Organic Compounds (VOC) emissions for the proposed

construction would be classified as de minimus and no further action would be

required.

7.2.7 National Historic Preservation Act of 1966

In compliance with Section 106 of the National Historic Preservation Act of 1966, as

amended, and 36CFR 800, Federal agencies are required to identify and consider

potential effects that their undertakings might have on any significant historic

property, district, site, building, structure, or object that is included in or eligible for

inclusion in the National Register of Historic Places. 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,

the proposed action has been coordinated with the SHPO and tribes. The

coordination letter received from the SHPO, as well as the Programmatic

Agreement, are included in Appendix F. The LCA ARDC Integrated Feasibility

Report and SEIS was provided to the SHPO and tribes, as well as other interested

parties for comment (see also Section 5.12).

7.2.8 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. There are no prime and unique

farmlands within the study area. Hence, there would be no unnecessary or

irreversible conversion of prime and unique farmland to non-agricultural uses.

7.2.9 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

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actions (Section 5.7). 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

Recommended Plan would result in a net increase in migratory bird habitat.

7.2.10 Executive Order 12898 – Environmental Justice

Concern with environmental justice 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 environmental justice 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

Environmental Justice issues have been considered throughout the entire study

process, and would 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. Comments did not identify any potential environmental justice

issues. The USACE is committed to ensuring that any potential environmental

justice issues are addressed as the study proceeds. The proposed ecosystem

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restoration measures would equally impact all potential users in the area. There

would be no potential environmental justice issues from implementing the

Recommended Plan (Section 5.15.4).

7.2.11 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. Alternative 33 (Recommended

Plan) 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. Alternative 33 (Recommended Plan) would 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 would be taken in

conjunction with the actions (Section 5.6.5).

7.2.12 Executive Order 11990 – Protection of Wetlands

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

Recommended Plan for ecosystem restoration and avoiding potential effects on the

survival and quality of wetlands (Appendix D):

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.

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7.2.13 Executive Order 11988 – Floodplain Management

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.

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 period of analysis 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; and

• 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 (Source: National

Flood Insurance Program, Firm Flood Insurance Rate Map, Livingston Parish,

Louisiana, Unincorporated Areas, Panel 250 of 275, Community-Panel Number

220113 0250 B, effective date September 30, 1988, Federal Emergency Management

Agency). Consistent with Executive Order 11988, implementing the Recommended

Plan would have no significant impacts on the risk of flood loss. Furthermore,

implementing the Recommended Plan would have no significant flooding impacts on

human safety, health and welfare. Implementing the Recommended Plan,

ecosystem restoration of portions of the Maurepas Swamp, would contribute to

restoring and preserving the natural and beneficial values served by floodplains

(Section 5.15.14.2).

7.2.14 Uniform Relocation Assistance and Real Property Acquisition

Policies Act of 1970 (Public Law 91-646)

All real estate interests acquired for construction of the Recommended Plan would

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 (Appendix J).

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7.2.15 Louisiana State Rare, Threatened, and Endangered Species, and

Natural Communities Coordination

The USACE reviewed the database maintained by the Louisiana Natural 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 is not likely to adversely affect

any rare, threatened or endangered species, or unique natural communities. The

proposed action would increase the extent of bald cypress-tupelo swamp within

portions of the study area, which are identified as rare natural communities for

certain regions of the state (see also Section 5.6 Vegetation Resources and 5.11

Threatened and Endangered Species).

7.2.16 Clean Water Act – Section 401 Water Quality

Under provisions of the Clean Water Act (33 U.S.C. § 1251), any project that

involved 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 SEIS addressing impacts of all

activities associated with the proposed LCA ARDC Modification project has been

prepared. The document includes an assessment of impacts of excavation, dredging,

and disposal operations. Application for certification has been submitted by the

U.S. Army Engineer District, New Orleans, to the LDEQ, Office of Environmental

Services, in accordance with statutory authority contained in LRS: 30:2074 A(3) and

provisions of Section 401 of the Clean Water Act (P.L. 92-500, as amended)

(Appendix D). A Water Quality Certification was received on September 20, 2010

and is included in Appendix D.

7.2.17 U.S. Fish and Wildlife Coordination Act Report

The USACE and the USFWS have formally committed to work together to conserve,

protect, and restore fish and wildlife resources while ensuring environmental

sustainability of our Nation's water resources under the January 22, 2003,

Partnership Agreement for Water Resources and Fish and Wildlife. Accordingly,

the USFWS indicated agreement to serve as a Cooperating Agency (per NEPA

section 1501.6) in developing the SEIS for the proposed project in accordance with

applicable NEPA and CEQ guidance. Participation of the USFWS includes

(1) participating in meetings and field trips to obtain baseline information on

project area fish and wildlife resources; (2) evaluating the proposed project's

impacts to wetlands and associated fish and wildlife resources, and assisting in the

development of measures to avoid, minimize, and/or compensate for those impacts;

and (3) providing technical assistance in the development of a Biological

Assessment describing the impacts of the proposed activity to Federally listed

threatened or endangered species and/or their critical habitat. In the January 20,

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2009, letter, the USFWS also provided specific guidance on avoiding impacts to

West Indian manatee (Trichechus manatus), Gulf sturgeon (Acipenser oxyrhynchus

desotoi), bald eagle (Haliaeetus leucocephalus), and colonial nesting waterbirds. The

U.S. Fish and Wildlife Coordination Letter and Report are provided in Appendix B.

We received concurrence on the Biological Assessment and recommendations in a

draft Coordination Act Report (CAR) in a letter from the USFWS, dated June 29,

2010. The final CAR was received on September 2, 2010.

Additionally, USACE has coordinated with the U.S. Fish and Wildlife Service,

National Marine Fisheries Service and the Louisiana Department of Wildlife and

Fisheries as per the Fish and Wildlife Coordination Act (16 U.S.C. 661-667e; the Act

of March 10, 1934; Ch. 55; 48 Stat. 401), as amended by the Act of June 24, 1936. A

Final coordination act letter report (Appendix B) has been received the services

position and recommendations are as follows:

The TSP will benefit the fish and wildlife resources of the LCA-ARDC area by

providing freshwater, nutrients, and sediments to the study area thus facilitating

sediment deposition, increase organic production, increase biological productivity,

and reduce conversion of swamp habitat to open water. Approximately 679 AAHUs

and 1,602 net acres of swamp habitats would benefit by the proposed project at the

end of the project life. The Service supports implementation of Alternative 33

provided the following fish and wildlife recommendations are implemented

concurrently with project implementation:

1. If authorized funding limits for this project are increased the Service

recommends that Alterative 39 be reconsidered as the potential future TSP.

2. Prioritize those measures that are contained in the NER plan that are not

included within the TSP based on cost-effectiveness. In addition, advertise

the most cost-effective measures in the NER plan that are missing from the

TSP as additive alternates if funds for this project are authorized by

Congress and the project is advertised for construction bids.

3. If a proposed project feature is changed significantly or is not implemented

within one year of the Endangered Species Act consultation letter, we

recommend that the Corps reinitiate coordination with our office to ensure

that the proposed project would not adversely affect any Federally listed

threatened or endangered species or their critical habitat.

4. 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

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during the nesting season (i.e., February 16 through October 31 for wading

bird nesting colonies, and October through mid-May for bald eagles).

5. To minimize disturbance to 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.

6. Because bald eagles are known to nest within the proposed study area, we

recommend that an evaluation 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 and those results should be

forwarded to this office.

7. Land clearing associated with project features should be conducted during

the fall or winter to minimize impacts to nesting migratory birds, when

practicable.

8. Further detailed planning of project features (e.g., Design Documentation

Report, Engineering Documentation Report, Plans and Specifications, or

other similar documents) should be coordinated with the Service and other

State and Federal natural resource agencies, and shall be provided an

opportunity to review and submit recommendations on the all work

addressed in those reports.

9. A report documenting the status of implementation, maintenance and

adaptive management measures should be prepared every three years by the

managing agency and provided to the Corps, the Service, National Marine

Fisheries Service, U.S. Environmental Protection Agency, Louisiana

Department of Natural Resources, Office of Coastal Protection and

Restoration, and the Louisiana Department of Wildlife and Fisheries. That

report should also describe future management activities, and identify any

proposed changes to the existing management plan.

References to the above USFWS recommendations and how each was addressed

are as follows:

• Recommendation 1 is addressed in Sections 1.5.1, 3.7, 3.9.6 and 6.2.3 of

this report;

• Recommendation 2 is addressed in Section 3.7 of this report;

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• Recommendations 3 and 8 are addressed in Section 7.2 of this report;

• Recommendations 4 and 7 are addressed in Section 5.7.2 of this report;

• Recommendations 5 and 6 are addressed in Section 4.2.7 of this report;

and

• Recommendation 9 is addressed in Section 3.7.5 and Appendix I of this

report.

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8.0 CONCLUSIONS AND DETERMINATIONS

8.1 AREAS OF CONTROVERSY AND UNRESOLVED ISSUES

The State of Louisiana, the U.S. Army Corps of Engineers (USACE), landowners

within the study area, and public stakeholders, have agreed on the goals, purpose,

and findings of this study, and there are no known areas of controversy or

unresolved issues.

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

at this time. 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. 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.).

8.2 CONCLUSIONS

The Recommended Plan, Alternative 33 includes:

• Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

channel in the north bank extending through the railroad grade into NE-1

to add connectivity between NE-1, NE-2, and the ARDC.

• Dredged material (5.0 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

would be left in the disposal berms so sheet flow is not reduced.

• One cut would be created in the railroad grade approximately 0.9 mile

north of the ARDC to improve sheet flow.

• Vegetative plantings of bottomland hardwood/freshwater swamp tree

species on 5.0 acres of dredged material berms.

• Vegetative plantings of freshwater swamp tree species within 438 acres of

the swamp floor.

• Installation of nutria guards on all newly planted trees to protect against

tree loss.

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Three natural low areas or relict channels have been identified as potential bank

opening and conveyance channel sites. Openings would enable impounded water to

be drained from the swamp and provide hydrologic connectivity between the swamp

and the ARDC. Additionally, the placement of a cut in the railroad grade would

provide further hydrologic connectivity on the north bank. Openings would promote

the introduction of freshwater, sediments, and nutrients into the swamp and allow

the oxidation of sediments and removal of toxic metabolites. This alternative is

anticipated to improve the degraded swamp and decrease the transition to marsh

and ultimately, open water. This alternative represents the minimum effort that

would meet the goals and objectives of the project.

The implementation of the recommended plan would result in long-term,

sustainable ecosystem restoration. Fish, wildlife, and freshwater swamp habitat

would be restored and maintained. The project outputs are cost-effective and

consistent with the mission of the USACE and the State of Louisiana Coastal

Protection and Restoration Authority (CPRA). This plan is acceptable to the public

and the State of Louisiana and the Project Delivery Team (PDT). The Non-Federal

Sponsor shall, prior to implementation, agree to perform the items of local

cooperation as discussed in Section 3.9.

8.3 RECOMMENDATIONS

I recommend that Alternative 33 be constructed under the authority of Section

7006(e)(3)(b) of the Water Resources Development Act (WRDA) 2007.

Alternative 33 includes the creation of three conveyance channels through the

dredged material berm of the ARDC to improve connectivity that would greatly

increase the movement of freshwater, sediments, and nutrients to and from the bald

cypress-tupelo swamp. It also includes planting of 438 and 5 acres of the study area

with freshwater swamp and bottomland hardwood tree species, respectively. The

recommended plan is an implementable increment of the NER plan, has been

determined to be cost effective, is within the cost and scope of the authorization, has

stand-alone utility, is supported by the non-Federal sponsor, and can be justified

based on ecosystem restoration benefits. Alternative 33 would create 679 Average

Annual Habitat Units (AAHUs), would benefit approximately 1,602 acres of existing

freshwater swamp, recreate 144 acres of freshwater swamp from freshwater marsh,

and create 5.0 acres of upland habitat from dredged material placement. The

project total first cost, based on October 2010 price levels, is estimated at

$8,136,000. The total fully funded project cost is estimated at $8,540,000 MicroComputer Aided Cost Estimating System (MCACES) and the average annualized

cost per AAHUs is $660. This restoration would greatly benefit fish and wildlife

resources, freshwater swamp habitat, and improve water quality. This project

would be cost shared by the non-Federal sponsor, the State of Louisiana at

35 percent non-Federal and 65 percent Federal. The Non-Federal Sponsor shall,

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prior to implementation, agree to perform the items of local cooperation as stated in

Section 3.9.2.

The recommendations contained herein reflects the information available at this

time, price levels as specified in the FS/SEIS, and current departmental policies

governing the formulation of the project. They do not reflect program and

budgeting priorities inherent in the formulation of a national civil works

construction program or the perspective of higher levels of review within the

Executive Branch. Consequently, the recommendation may be modified before it is

transmitted to the Congress as a proposal for implementation funding.

Edward Fleming

Colonel, U.S. Army

District Engineer

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9.0 DISTRIBUTION LIST AND OTHER

9.1 DISTRIBUTION LIST

The LCA ARDC Integrated Feasibility Report and Supplemental Environmental

Impact Statement (FS/SEIS) will be distributed to Federal, state, parish, and local

agencies; tribes; businesses; libraries; museums; universities; environmental

organizations, groups and individuals; and scoping participants. The complete

distribution list would be available upon request from the U.S. Army Corps of

Engineers at the following address.

U.S. Army Corps of Engineers

New Orleans District

P.O. Box 60267

New Orleans, Louisiana 70160-0267

9.2 LIST OF PREPARERS

Many individuals were involved with the completion of this document. Table 9.1

lists those people who assisted in the writing of the LCA ARDC FS/SEIS. Table 9.1

is alphabetized by preparers' last name.

Table 9.1. List of Preparers

Name Subject Matter Affiliation

Donald Alette H&H USACE

James Altman Landrights Manager CPRA

Timothy Axtman Senior Planner USACE

Jacques Bagur Economics Contractor G.E.C., Inc.

Tomma Barnes Planning/Adaptive Management USACE

Steve Bartlett Adaptive Management E2 Consulting Engineers

Adam Baumgart-Getz GIS USGS

Bob Bosenberg Project Management USACE

Michelle Boudreaux Planner/USACE Contractor USACE

Mayely Boyce Legal Council USACE

Laura Brandt Adaptive Management USFWS

Louis Britsch Geologist USACE

Darrel Broussard Project Management USACE

Christopher Brown HTRW USACE

Drew Buchner Cultural Resources Contractor PanAmerican Consultants, Inc.

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Name Subject Matter Affiliation

Eddy Carter Senior NEPA Analyst G.E.C., Inc.

Annette Chioma Project Management USACE

Erin Clark Real Estate USACE

Troy Constance Chief of Planning Division USACE

Mathew Crawford Engineering USACE

Kelly Danton Geotechnical USACE

Elizabeth Davoli NEPA Compliance Support CPRA

Pamela Deloach Engineering USACE

Gary Demarcay Cultural Resources USACE

Jammie Favorite LCA Program Manager CPRA

Craig Fischenich Adaptive Management USACE/ERDC

Tye Fitzgerald Project Engineer CPRA

Judith Gutierrez Real Estate USACE

Mark Haab Economics USACE

Suzanne Hawes Planning USACE

George Hudson, P.E. H&H Modeling Taylor Engineering

Kristin Johnson Civil USACE

William P. Klein, Jr. Environmental Lead USACE

Barbara Kleiss Adaptive Management USACE

Jennifer Lindquist Water Quality Contractor G.E.C., Inc.

Kelly McCaffrey Aesthetics USACE

Robert Manes, P.E. NEPA Contractor G.E.C., Inc.

Joe Mann Economics USACE

Summer Martin Environmental Manager CPRA

Gregory Miller Plan Formulation Branch Chief USACE

Dona Ours Project Manager CPRA

Andrew Perez Recreation USACE

John Petitbon Senior Oversight Cost USACE

Jonathan Puls, P.E. Project Manager Contractor G.E.C., Inc.

Ronnie Rabalais Real Estate SJB Group

Miguel Ramos-Lebron Cost USACE

Carol Parsons Richards Adaptive Management CPRA

Jerica Richardson Environmental Justice USACE

Renee Sanders Study Manager CPRA

Gary Shaffer Environmental Subcontractor Southeastern Louisiana

University

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Name Subject Matter Affiliation

Karen Soileau WVA Modeling USFWS

Greg Steyer Adaptive Management USGS

Chuck Villarrubia LACES CPRA

William Wood Environmental Subcontractor Southeastern Louisiana

University

Joseph Wyble Project Manager Contractor G.E.C., Inc.

Andrea Zachary NEPA Contractor G.E.C., Inc.

Caitlan Zlatos H&H USACE

9.3 LITERATURE CITED

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Barras, J.A., J.C. Bernier, and R.A. Morton. 2008. Land area change in coastal

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G.P. Shaffer. 2005. Conservation, Protection and Utilization of Louisiana’s

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Suite 138, Baton Rouge, LA 70804.

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baldcypress-water tupelo site and a bottomland hardwood site in a Louisiana

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nutria damage to planted baldcypress seedlings. Tree Planter’s Notes 38:26-

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distichum (L.) Rich.) planted across a flooding gradient in a Louisiana

bottomland forest. Wetlands 9(2):207-217.

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historical wetland loss in the Mississippi Delta Plain, likely causes and

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intrusion: potential effects on survival and productivity of wetland forests

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Trajectory? Journal of Coastal Research, SI(54), 152-165. West Palm Beach

(FL), ISSN 0749-0208.

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9.4 GLOSSARY

Acceptability Adequate to satisfy a need, requirement, or standard. One

of the USACE 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 functioning

together to address one or more objectives.

Amplitude The maximum absolute value of a periodically varying

quantity.

Anadromous Species that ascend rivers from the sea to spawn.

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Anoxia Absence of oxygen.

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, averaged over the

project life, to determine Average Annual Habitat Units

(AAHUs).

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 found at higher elevations than swamp.

Clean Water Act Section

404 (b) (1)

There are several sections of this Act which pertain to

regulating impacts to 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.

Coastal Zone

Consistency

Determination

The U.S. Environmental Protection Agency reviews plans

for activities in the coastal zone to ensure they are

consistent with Federally approved State Coastal

Management Programs under Section 307(c)(3)(B) of the

Coastal Zone Management Act.

Coastwide Plan Combination of alternative plans assembled to address an

objective or set of objectives across the entire Louisiana

Coast.

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.

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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.

Continental Shelf The edge of the continent under gulf waters; the shallow

Gulf of Mexico fringing the coast.

Control Structure A gate, lock, or weir that controls the flow of water.

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.

Decomposition Breakdown or decay of organic materials.

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 The repeating pattern of delta development, progression,

and abandonment. As sediments are deposited at the

mouth of the distributary channels, the delta progresses

seaward. The main channel then switches to a new course

with a shorter reach to the depositional basin. Abandoned

delta lobes decrease in elevation due to continued

subsidence and sediment compaction, resulting in retreat

of the shoreline. Abandoned lobes may be partially or

wholly covered by new lobes during later deltaic cycles.

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.

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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 Impacts.”

Diurnal Active during the day.

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 (Dredged

material berms, Sidecast 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.

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.

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Ecosystem Restoration Activities that seek to return an 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

requirements for a project.

Efficiency The quality of exhibiting a high ratio of output to input.

One of the USACE 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.

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).

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

A collaboration among Federal agencies at the Washington

level to facilitate the flow of information, to provide

guidance and recommendations to the USACE and OCPR

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 plans from which a

final recommendation can be made.

Fresh Marsh 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 (mammal),

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.

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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.

Habitat Units (HUs) 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 withproject 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 withproject scenarios. The difference in 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)

Wastes that contain toxic constituents, or that may cause

hazardous chemical reactions, including explosive or

flammable materials, or radioactive wastes, which,

improperly managed may present a hazard to human

health or the environment.

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.

Hypoxia The condition of low dissolved oxygen concentrations.

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.

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Ingress An entrance or the act of entering.

Inorganic Not derived from living organisms; mineral; matter other

than plant or animal.

Intermediate Marsh 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.

Invertebrates Animals without backbones, including shrimp, crabs,

oysters, and worms.

Leeward Sheltered from the wind; away from the wind.

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. Levees are used in the New Orleans

Hurricane Storm Damage Risk Reduction System.

Maintain To keep in existing state.

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.

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.

Net Loss The amount of cumulative land gain less land loss, when

gain is less than loss.

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No Action Alternative The alternative in the NEPA document 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.

Oxidation of Organic

Matter

The decomposition (rotting, breaking down) of plant

material through exposure to oxygen.

Oxygen-depleted Situation of low oxygen concentrations where living

organisms are stressed.

Potable Water Water that is fit to drink.

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 NEPA document.

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.

Progradation The phase during the deltaic cycle where land is being

actively accreted through deposition of river sediments

near the mouth.

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.

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Province A major division of the coastal area of Louisiana. (e.g.,

Deltaic Plain and Chenier Plain).

Quantitative Able to assign a specific number; susceptible to

measurement.

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 rise; the change in average water level

with respect to the surface.

Restore Return a wetland to an 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.

Salinity The concentration of dissolved salts in a body of water,

commonly expressed as parts per thousand.

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.

Sheet Flow Flow of water, sediment, and nutrients across a flooded

wetland surface, as opposed to through channels.

Supplemental

Environmental Impact

Statement (SEIS)

Typically prepared after either a Final EIS or Record of

Decision has been issued and new environmental impacts

that were not considered in the original EIS are discovered,

requiring the lead agency to re-evaluate its initial decision

and consider new alternatives to avoid or mitigate the new

impacts. Supplemental EISs are also prepared when the

size and scope of a Federal action changes, or when all of

the proposed alternatives in an EIS are deemed to have

unacceptable environmental impacts and new alternatives

are proposed.

Social Relating to human society and its modes of organization.

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Socioeconomic Involving both social and economic factors.

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 oversees consultation and

compliance with Section 106 of the National Historic

Preservation Act for Federally funded, permitted, or

approved projects.

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 Gauging 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.

Target A desired ecosystem state that meets an objective or set of

objectives.

Terrestrial Habitat The land area or environment where an organism lives; as

distinct from water or air habitats.

Toxicity The measure of how poisonous something is.

Transpiration The process by which water passes through living plants

into the atmosphere.

Turbidity The level of suspended sediments in water; opposite of

clarity or clearness.

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Upland A general term for non-wetland elevated land above low

areas along streams or between hills.

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 low head dam placed across a canal or river to raise,

divert, regulate or measure the flow of water.

9.5 ACRONYMS, ABBREVIATIONS, SYMBOLS, AND INITIALISMS

AAHU Average Annual Habitat Unit

ACHP Advisory Council on Historic Preservation

AFB Alternative Formulation Briefing

AQI Air Quality Index

ARDC Amite River Diversion Canal

AR&T Amite River and Tributaries

ASA (CW) Assistant Secretary of the Army (for Civil Works)

AST Aboveground Storage Tank

ASTM American Society for Testing and Materials

ATR Agency Technical Review

BGEPA Bald and Golden Eagle Protection Act

BMP Best Management Practices

BOD Biochemical Oxygen Demand

BRP Blind River Properties

CAR U.S. Fish and Wildlife Service, Coordination Act Report

CE/ICA Cost Effectiveness/Incremental Cost Analysis

CEM Conceptual Ecological Model

CEMVN Corps of Engineers Mississippi Valley New Orleans

CEQ Council on Environmental Quality

CERCLA Comprehensive Environmental Response, Compensation, and

Liability Act

CFR Code of Federal Regulations

cfs Cubic feet per second

CIAP Coastal Impact Assistance Program

CO Carbon Monoxide

COE Corps of Engineers

CPRA Coastal Protection and Restoration Authority

CRMS Coastwide Reference Monitoring System

CS Clearing and Snagging

CSA Cost Share Agreement

CWA Clean Water Act

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CWPPRA Coastal Wetlands Planning, Protection, and Restoration Act

CZM Coastal Zone Management Act of 1972

DBH Diameter at Breast Height

DEMCO Dixie Electric Membership Corporation

DNR Department of Natural Resources

DO Dissolved Oxygen

DOA Department of the Army

DOTD Department of Transportation and Development

DSEIS Draft Supplement Environmental Impact Statement

DWC Division Water Company

EATEL East Ascension Telephone Company

EFH Essential Fish Habitat

EIS Environmental Impact Statement

EO Executive Orders

EOP Environmental Operating Principles

EPA Environmental Protection Agency

ER Engineering Regulation

ESA Endangered Species Act

ESA Phase I Environmental Site Assessment

FCSA Feasibility Cost Share Agreement

FMC Fishery Management Council

FMP Fishery Management Plan

FSWC French Settlement Water Company

ft Feet

FWOP Future Without Project

FWP Future With Project

GIS Geographic Information System

HEC-RAS Hydraulic Engineering Centers River Analysis

H&H Hydraulics and Hydrology

HQUSACE Headquarters, U.S. Army Corps of Engineers

HSI Habitat Suitability Index

HTRW Hazardous, Toxic and Radioactive Waste

ICA Incremental Cost Analysis

ISQG Interim Sediment Quality Guidelines

ITR Independent Technical Review

IWR Institute for Water Resources

LA Louisiana

LACPR Louisiana Coastal Protection and Restoration

LCA Louisiana Conservation Area

LCF Louisiana Conservation Fund

LCWCR Louisiana Coastal Wetlands Conservation and Restoration

Authority

LCWCRTF Louisiana Coastal Wetlands Conservation and Restoration Task

Force

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LDAF Louisiana Department of Agriculture and Forestry

LDEQ Louisiana Department of Environmental Quality

LDNR Louisiana Department of Natural Resources

LDWF Louisiana Department of Wildlife and Fisheries

LERRD Lands, Easements, Right-of-Way, Relocation, and Disposal

Areas

LNHP Louisiana National Heritage Program

m Meters

MBTA Migratory Bird Treaty Act

MCACES Micro-Computer Aided Cost Engineering System

mm Millimeter

MMPA Marine Mammal Protection Act

MMS Minerals Management Service

MR&T Mississippi River and Tributaries

MRC Mississippi River Commission

MSA Metropolitan Statistical Area

MSFCMA Magnuson-Stevens Fishery Conservation and Management Act

msl Mean Sea Level

MVD U.S. Army Corps of Engineers, Mississippi Valley Division

MVN U.S. Army Corps of Engineers, Mississippi Valley Division, New

Orleans District

NAAQS National Ambient Air Quality Standards

NAVD North American Vertical Datum

NBEM National Bald Eagle Management Guidelines

NEPA National Environmental Policy Act

NER National Ecosystem Restoration

NERP National Ecosystem Restoration Act

NGO Non-governmental Organization

NGVD National Geodetic Vertical Datum

NHPA National Historic Preservation Act

NMFS National Marine Fisheries Service

NO2

NOAA National Oceanic and Atmospheric Administration

Nitrogen Dioxide

NOI Notice of Intent

NPDES National Pollution Discharge Elimination System

NRC National Resource Council

NRCS National Resources Conservation Service

NWI National Wetlands Inventory

OCPR Office of Coastal Protection and Restoration

OCS Outer Continental Shelf

OMRR&R Operations, Maintenance, Repair, Replacement, and

Rehabilitation

ONWR Outstanding Natural Resource Water

OSHA Occupational Safety and Health Administration

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Pb Lead

P&G Principles and Guidelines

PCR Primary Contact Recreation

PDT Project Delivery Team

PED Planning, Engineering, and Design

PGM Planning Guidance Memo

Pm Particulate Matter

PMP Project Management Plan

PPA Project Partnership Agreement

PPL Priority Project List

POR Period of Record

PRP Preliminary Restoration Plan

ppt Parts per Thousand

QCP Quality Control Plan

RCRA Resource Conservation and Recovery Act

RCRAGN Resource Conservation and Recovery Act Generator

RCRATSD Resource Conservation and Recovery Act Treatment, Storage,

and Disposal

REC Recognized Environmental Condition

REP Real Estate Plan

ROD Record of Decision

ROE Rights-of-Entry

RSLR Relative Sea level Rise

RV Recreational Vehicle

S&A Supervision and Administration

SAV Submerged Aquatic Vegetation

SCR Secondary Contact Recreation

SEIS Supplemental Environmental Impact Statement

SET Surface Elevation Table

SHPO State Historic Preservation Office

SONRIS Strategic Online Natural Resources Information System

SOP Standard Operating Procedure

SPCC Spill Prevention Control and Countermeasure Plan

S&T Science and Technology

SWPPP Storm Water Pollution Prevention Plan

TDS Total Dissolved Solids

THPO Tribal Historic Preservation Officer

TM Landsat Thematic Mapper

TMDL Total Maximum Daily Load

TOC Total Organic Carbon

TOD Tract Ownership Data

TRI Toxic Release Inventory

TSP Tentatively Selected Plan

TSS Total Suspended Solids

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um Micrometers

USDA United States Department of Agriculture

USACE U.S. Army Corps of Engineers

USACE-MVM U.S. Army Corps of Engineers-Mississippi Valley Memphis

District

USACE-MVN U.S. Army Corps of Engineers-Mississippi Valley New Orleans

District

USC United States Code

USEPA U.S. Environmental Protection Agency

USFWS U.S. Fish and Wildlife Service

USGS U.S. Geological Survey

UST Underground Storage Tank

VE Value Engineering

VOC Volatile Organic Compound

VRAP Visual Resources Assessment Procedure

WBS Work Breakdown Structure

WC Weir Construction

WCRF Wetland Conservation and Restoration Fund

WR Weir Rehabilitation

WCRA Wetland Conservation and Restoration Authority

WRDA Water Resources Development Act

WMA Wildlife Management Area

WVA Wetland Value Assessment

yr Year

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434
MAIN REPORT

ATTACHMENT 1

Non-Federal Sponsor’s Letter of Intent

435
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436
437
438
  	 

 
    	

Integrated Feasibility Study an ronmental Impact Statement d Envi

 

LCA Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

(APPENDICES A  M)

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. 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.

 2010

U.S Army Corps of Engineers

New Orleans District Coastal Protection and Restoration

Authority

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440
Appendix A

BIOLOGICAL ASSESSMENT

441

1

APPENDIX A

BIOLOGICAL ASSESSMENT

AMITE RIVER DIVERSION CANAL MODIFICATION PROJECT, LIVINGSTON AND

ASCENSION PARISHES, LOUISIANA

1.0 PURPOSE

Section 7(a)(2) of the Endangered Species Act (ESA) of 1973, as amended, requires that, “Each Federal

agency shall, in consultation with and with the assistance of the secretary, insure that any action

authorized, funded, or carried, out by such agency.... Is not likely to jeopardize the continued existence of

any endangered species or threatened species or result in the destruction or adverse modification of

habitat of such species...”.

This Biological Assessment provides the information required pursuant to the ESA and implementing

regulation (50 CFR 402.14), to comply with the ESA. Additional jurisprudence includes the National

Environmental Policy Act (NEPA) of 1969, 42 U.S.C. section 4321, et seq.; the Fish and Wildlife

Conservation Act of 1958 (PL 85-624; 16 U.S.C. 661 et seq.); the Marine Mammal Protection Act of

1972; and the Bald Eagle Protection Act of 1940.

This Biological Assessment (BA) evaluates the potential impacts of the Tentatively Selected Plan (TSP)

described in the Integrated Feasibility Report and Environmental Impact Statement for the Amite River

Diversion Canal (ARDC) Modification project on Federally-listed threatened and endangered species,

and their critical habitat. This evaluation is presented to the U.S. Fish and Wildlife Service (USFWS) and

the National Marine Fisheries Service (NMFS) to achieve compliance with the requirements of Section 7

of the ESA for consultation with USFWS and NMFS.

2.0 LOCATION AND GENERAL DESCRIPTION

OF THE STUDY AREA

The Louisiana Coastal Area (LCA) program study area (LCA ARDC) (Figures 1 and 2) is situated along

the ARDC in Ascension and Livingston parishes, in the vicinity of Head of Island, Louisiana. The study

area is bounded to the north by the old channel of the Amite River, Old River, Chinquapin Canal and

Bayou Chene Blanc; to the east by the Blind River; to the south by the Petite Amite River and the New

River Canal; and to the west by the Sevario Canal, Ascension Parish flood protection levees, and the

Laurel Ridge Canal; and is located in the following sections:

• Township 9 South, Range 4 East, Sections 9-16, 22-27, and 34-36;

• Township 9 South, Range 5 East, Sections 7, 14-36;

• Township 9 South, Range 6 East, Section 30;

443
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:Source: USDA/GEC

STUDY AREA REGION

Map ID: 27850108-1781

Lake

Maurepas

Lake

Pontchartrain

22

Mississippi River

Iberville

Parish

Amite River Diversion Canal

Blind River

Amite River

Amite River

Livingston Parish

Ascension Parish

St. John the Baptist Parish

Tangipahoa

Parish

St. James Parish

East Baton

Rouge Parish

10

12

61

51

22

444

70

16

42

74

447

621

30

63

928 931 44

431

1037

933

941

426

429

932

929

641

934

935

1026

1033

3115

1039

427

1038

937

930

936

43

938

441

1032

42

22

42

22

73

429

42

18

942

61

405

55

Killian

Garyville Reserve

Baton Rouge

Gonzales

Sorrento

St.

Gabriel

French

Settlement

Port

Vincent

Springfield

Lutcher

1:260,000

0246 1

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study AreaCities and TownsParishesWater Bodies

Figure: 1

444
Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:Source: USDA/GEC

STUDY AREA AND SUBUNITS

Map ID: 27850108-1780

Little Bayou Chene Blanc

Bayou C hene

B

la

n

c

NW-2

SE-1

SW-2

NE-2 NE-1

SE-2

NE-3

Blind River

Amite River Diversion Canal

New River Canal

Petite Amite River

Chinquapin Canal

NW-1

SW-1

Weir

Old RailroadEmbankment

Laurel Ridge Canal

Flat

Lake

Petite A mite R vi

re

Alligator Bayo u

Bayou An

ot

ni e

Bayou Chene Blanc

New River

O ld River

Petite Amite River

a B you

i P er er

Ba

oy

V

u

ci knair

Heath Bayou

1:80,000

0 0.5 1 1.5 2

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study Area Subunits

Figure: 2

445
4

• Township 10 South, Range 4 East, Sections 1-3 and 10-12; and

• Township 10 South, Range 5 East, Sections 2-11.

For planning purposes, the study area has been divided into nine separate hydrologic subunits (Figure 2).

Each subunit was developed based on hydrologic differences that exist throughout the study area due to

natural and manmade hydrologic boundaries. These boundaries include natural topography such as

dredged material berms and natural ridges, as well as man-made and natural canals.

3.0 PROPOSED ACTION

Alternative 33 of the LCA ARDC Integrated Feasibility Report and Supplemental Environmental Impact

Statement (SEIS) is the Tentatively Selected Plan (TSP), which is depicted in Figure 3. Features of the

TSP include:

• Three dredged material bank openings and three bifurcated conveyance channels in the north

bank of the ARDC in NE-2 with the westernmost channel in the north bank of the ARDC also

extending through the railroad grade into NE-1 to add connectivity between NE-1, NE-2, and

the ARDC.

• Dredged material (5.0 acres) from the bank openings and the conveyance channel would be

sidecast on both sides of the proposed channel. Gaps will be left in the disposal berms so

sheet flow is not reduced.

• One cut would be created in the railroad grade approximately 0.9 miles north of the ARDC to

improve sheet flow.

• Vegetative plantings of bottomland hardwood/freshwater swamp tree species on 5.0 acres of

dredged material berms.

• Vegetative plantings of freshwater swamp tree species within 438 acres of the swamp floor.

Three natural low areas or relict channels have been identified as potential bank opening and conveyance

channel sites. Openings would enable impounded water to be drained from the swamp and provide

hydrologic connectivity between the swamp and the ARDC. Additionally, the placement of a cut in the

railroad grade would provide further hydrologic connectivity between NE-1 and NE-2. Openings would

promote the introduction of freshwater, sediments, and nutrients into the swamp and allow the oxidation

of sediments and removal of toxic metabolites. This alternative is anticipated to improve the degraded

swamp and decrease the transition to marsh and ultimately, open water. This alternative represents the

minimum effort that would meet the goals and objectives of the project. Alternative 33 would benefit

approximately 1,602 acres of existing freshwater swamp, recreate 144 acres of freshwater swamp from

freshwater marsh, and create 5.0 acres of upland habitat from dredged material placement.

All excavation through the dredged material berms, as well as the conveyance channels through the

swamp, would be based on four design cross-sections. These cross-sections were developed in an effort to

mimic natural, existing cuts within the study area, which have been determined to be self-maintaining.

Several existing channels were surveyed for depth, dimension, and profile. These channels have existed

for quite some time without any maintenance. The cross-sections include a 70-foot wide cut section with

benches through dredged material berm, a 70-foot wide cut section, a 50-foot wide cut section and a 30-

foot wide cut section. The 70-foot cut section with benches was designed to allow increased amounts of

flow to pass beyond the existing dredged material berm during high-water events. The material dredged

from the existing berms would be placed along the swamp-side of the excavated cut as new bottomland

hardwood habitat. All material dredged during construction of the conveyance channels would be placed

along the channels, with gaps included, to allow sufficient sheet flow to be conveyed from the swamp.

446
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 33

Map ID: 27850108-1868

LITTLE BAYOU CHENE BLANC

NE-2

SE-2

NE-3

SE-1

NE-1

Railroad

Grade 956 Acres

Secondary

Impact Area

438 Acres

Proposed

Vegetative

Planting

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

BAYOU

BAYOU CHENE BLANC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

BLANC

CHENE

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

SE-1

Material Berm

Notes:Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 3

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6

4.0 SPECIES DESCRIPTIONS

Two endangered species have been identified as potentially occurring within the boundaries of the study

area. Therefore, the proposed action could possibly impact the Gulf sturgeon (Acipenser oxyrhynchus

desotoi) and the West Indian manatee (Trichechus manatus).

The American alligator (Alligator mississippiensis), a common inhabitant of the study area, is classified

by USFWS as “Similarity of Appearance to a Threatened Taxon.” (The species to which it is similar is

the American crocodile (Crocodylus acutus), a threatened species.)

In addition, the study area contains a nesting pair of bald eagles (Haliaeetus leucocephalus). The bald

eagle was removed from the endangered species list in 2007, but is currently undergoing five years of

monitoring to confirm the revised status.

The two endangered species, Gulf sturgeon (Acipenser oxyrhynchus desotoi), and West Indian manatee

(Trichechus manatus), could potentially be found in the project area. Nevertheless, the features of the

proposed action would not adversely impact either species’ critical habitat, which is not present within

the study area. Manatees are rare transient foragers in the study area.

.1 AMERICAN ALLIGATOR (ALLIGATOR MISSISSIPPIENSIS)

The American alligator’s range extends across the southeastern states from North Carolina to Texas

(University of Florida, 1998). This reptile’s primary habitat includes freshwater swamps and marshes,

but it also inhabits rivers, lakes and smaller bodies of water. Alligators are an important part of their

ecosystem, and many biologists consider them a “keystone” species, performing many functions, from

control of prey species to the creation of peat through their nesting activities (University of Florida,

1998). Populations of the American alligator severely declined in the early part of the 20th century, due

to hunting of the animal for its skin. In 1967, this species was listed as endangered, and hunting was

prohibited. As a result, the alligator has undergone a successful recovery. Alligator hunting is allowed

again; however, permits are issued by lottery only during alligator hunting season.

The alligator is classified by USFWS as “Similarity of Appearance (Threatened).” The species to which

it is similar is the American crocodile (Crocodylus acutus), a threatened species. In the United States, the

American crocodile is found only in southern peninsular Florida. Because of its similarity to the

crocodile, the USFWS regulates the legal trade in alligator skins, or products made from them, to protect

the crocodile, whose skin is similar in appearance, but illegal in the commercial market.

4.2 BALD EAGLE (HALIAEETUS LEUCOCEPHALUS)

Status

The bald eagle is protected under the Bald and Golden Eagle Protection Act and the Migratory Bird

Treaty Act. The eagle was removed from the endangered species list in 2007, but is currently

undergoing five years of monitoring to confirm the revised status. Its status is Federally classified as

“Delisted Taxon-Recovered” in Louisiana.

Species, Habitat, and Distribution

The bald eagle is the only species of sea eagle native to North America. Adults are black with a snowwhite head and tail. Sub adults are mottled brown and black and lack the distinctive white head and tail.

Wingspan is 6 to 7 feet with females weighing between 10-14 lbs. and males weighing between 8-10 lbs.

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7

Bald eagles nest in Louisiana from October through mid-May, primarily in cypress snags in swamps or

near fresh to intermediate marshes or open water in the southeastern parishes. Bald eagles will often

return to the same nest for a number of years; however, they may also use alternate nests within the

vicinity. Shoreline trees that provide a clear view of the water to locate aquatic prey are often chosen as

nest sites. Bald eagles primarily feed on fish, but are opportunistic and will eat a variety of mammals,

amphibians, crustaceans, and birds. Wintering habitat used by bald eagles in Louisiana is characterized

by abundant, readily available food sources. Most wintering areas are associated with open water where

eagles feed on fish or waterfowl.

Management and Protection

According to The USFWS National Bald Eagle Management Guidelines, the proposed action would fall

under “Category A,” which includes construction of roads, trails, canals, power lines, and other linear

activities, and alteration of shorelines or wetlands. Table 1 provides the guidelines for activities in

Category A.

Table 1. Closest distances activities in Category A should be

conducted relative to the location of a bald eagle nest.

Visibility If there is no similar activity

within 1 mile of the nest

If there is similar activity closer than

1 mile from the nest

If the activity will

be visible from

the nest

660 feet. Landscape buffers are

recommended

660 feet, or as close as existing

tolerated activity for similar scope.

Landscape buffers are recommended.

If the activity will

not be visible

from the nest

330 feet. Clearing, external

construction, and landscaping

between 330 feet and 660 feet

should be done outside breeding

season.

330 feet, or as close as existing

tolerated activity of similar scope.

Clearing, external construction, and

landscaping within 660 feet should be

done outside breeding season

Source, USFWS, 2007.

4.3 GULF STURGEON (ACIPENSER OXYRHYNCHUS DESOTOI)

Status

On September 30, 1991, the Gulf sturgeon was listed as a threatened species under the Endangered

Species Act, 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, Habitat, and Distribution

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 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; adult females are larger than adult males.

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8

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. 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.

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. 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 fresh water vary depending on the fish’s life history stage. Young-ofthe-year Gulf sturgeon remain in fresh water feeding on aquatic invertebrates and detritus approximately

10 to 12 months after spawning occurs (Mason and Clugston, 1993. 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) feed only 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 sturgeon’s diet is predominantly amphipods, lancelets, polychaetes, gastropods, shrimp, isopods,

mollusks, and crustaceans (Huff, 1975; Mason and Clugston, 1993; Fox et al., 2000 and 2002, see

http://www.fws.gov).

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. 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).

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 Louisiana and Mississippi, east to the

Suwannee River in Florida, with infrequent sightings occurring west of the Mississippi River.

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 (U.S. Army Corps of Engineers [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

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9

percent were adults (Morrow et al., 1998, see http://www.fws.gov). The annual mortality rate was

calculated to be 25 percent.

In contrast, preliminary results from Pearl River captures between 1992 and 2001 suggest a stable

subpopulation of 430 fish, with approximately 300 adults (Rogillio et al., 2007, 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. Through agreements reached under Section 6(a) of the ESA, 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.

4.4 WEST INDIAN MANATEE (TRICHECHUS MANATUS)

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 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; pregnancy is estimated to last 12 to 14 months (O’Shea et al., 1992). Births occur

year-round 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 fresh water 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

451
10

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.

During winter months, the United States’ manatee population is confined 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 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) (O’Shea, 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 longterm 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).

5.0 DETERMINATION OF EFFECTS OF THE PROPOSED ACTION

The potential exists that the protected species in the study area may be present during proposed

construction activities. However, while individuals may be affected, whole populations would not be

adversely affected by implementation of the proposed action.

5.1 AMERICAN ALLIGATOR

The American alligator is a commonly encountered resident of the ARDC study area. The project is

unlikely to result in any damage to individuals, who are easily capable of avoiding the construction

taking place along the ARDC. The scope of activities constitutes a Not Likely to Adversely Affect

determination for the species and its critical habitat.

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11

5.2 BALD EAGLE

The design of the proposed action was amended to avoid any construction within 660 feet of the known

location of a bald eagle nest. Therefore, scope of activities constitutes a Not Likely to Adversely Affect

determination for the species and its critical habitat.

5.3 GULF STURGEON

The proposed action would involve activities outside the critical habitat of the Gulf sturgeon. Potential

project-induced impacts, however unlikely, may result from incidental interaction with the Gulf sturgeon

during the excavation for the construction of gaps in the dredged material banks of the ARDC. The

scope of activities constitutes a Not Likely to Adversely Affect determination for the species and its

critical habitat.

5.4 WEST INDIAN MANATEE

Sightings of the West Indian manatee in Louisiana have occurred in the Amite, Blind, Tchefuncte, and

Tickfaw Rivers, Mississippi River Gulf Outlet (MRGO), and in canals within the adjacent coastal

marshes of Louisiana. However, there is no known population thriving in the State. On July 9, 2001, a

manatee was observed passing safely through the Inner Harbor Navigation Canal (IHNC) Lock and into

the Mississippi River. 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.

The scope of activities constitutes a Not Likely to Adversely Affect determination for the species and its

critical habitat.

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.

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) of 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 re-established.

(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

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12

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" x 11" (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 SHUT

DOWN 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 USACE will be Edward Creef, (504) 862-2521,

FAX (504) 862-2317.

6.0 LITERATURE CITED

Ackerman, B.B. 1995. Aerial surveys of manatees: a summary and progress report. Pp. 13-33 in T.J.

O’Shea, B.B. Ackerman, and H.F. Percival (eds.). Population Biology of the Florida Manatee.

National Biological Service, Information and Technology Report No. 1. Washington, D.C.

Boschung, H (ed.). 1976. Endangered and threatened plants and animals of Alabama. Bull. AL

Mus.Nat. Hist. No. 2. Univ.of AL, Tuscaloosa, AL. Pp. 57.

Clugston, J.P., A.M. Foster, and S.H. Carr. 1995. Gulf sturgeon, Acipenser oxyrhynchus desotoi, in the

Suwannee River, Florida, USA. Proc. of International Symposium on Sturgeons. Moscow, Russia.

Editors: A.D. Gershanovich and T.I.J. Smith. Sept. 6-11, 1993. 370 pp.

Foster, A.M. 1993. Movement of Gulf sturgeon, Acipenser oxyrhynchus desotoi, in the Suwannee

River, Florida. Master Thesis, Univ. of FL, Gainesville, FL. 131 pp.

Fox, D. A.; Hightower, J. E.; Parauka, F. M. 2000. Gulf sturgeon spawning migration and habitat in the

Choctawhatchee River system, Alabama-Florida. Trans. Amer. Fish. Soc. 129: 811-826.

Fox, D., Hightower, J. and F. Parauka. 2002. Estuarine and nearshore marine habitat use by gulf

sturgeon from the Choctawhatchee River System, Florida. Amer. Fish. Society Symposium 28, 111-

126.

Hartman, D.S. 1979. Ecology and behavior of the manatee (Trichechus manatus) in Florida. Amer.

Soc. Mammalogists Spl. Publ. No. 5. 153 pp.

Huff, J.A. 1975. Life history of the Gulf of Mexico sturgeon, Acipenser oxyrhynchus desotoi, in

Suwannee River, FL. Mar. Res. Publ. No. 16. 32 pp.

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Husar, S.L. 1977. The West Indian manatee (Trichechus manatus). U.S. Fish and Wildlife Service.

Wildl. Res. Rpt. No. 7: 1-22.

Mason, W.T. Jr., and J.P. Clugston. 1993. Foods of the Gulf sturgeon in the Suwannee River, Florida.

Trans. Amer. Fish. Soc. 122: 378-385.

McDowall, R.M. 1988. Diadromy in fish migrations between freshwater and marine environments.

Truder Press and Croom Helm. 308 pp.

Morrow, J.V. Jr. J.P. Kirk, and K.J. Killgore. 1998. Status and Recovery Potential of Gulf Sturgeon in

the Pearl River System, Louisiana–Mississippi. No. Amer. J. Fish. Mg .1998; 18: 798-808

Odenkirk, J.S. 1989. Movements of Gulf of Mexico sturgeon in the Apalachicola River, Florida. Proc.

Ann. Conf., Southeastern Assoc. Fish & Wildl. Agencies 43: 230-238.

O’Shea, T.J., B.B. Ackerman, and H.F. Percival (eds.). 1992. Interim report of the technical workshop

on manatee population biology. Manatee Population Res. Rpt. No. 10. FL Coop. Fish & Wildl. Res.

Unit. Gainesville, FL. 83 pp.

Parauka, F.M., W.J. Troxel, F.A. Chapman, and L.G. McBay. 1991. Hormone-induced ovulation and

artificial spawning of Gulf of Mexico sturgeon, Acipenser oxyrhynchus desotoi. Prog. Fish-Culturist

53(2): 113-117.

Reynolds, J.E. III and J.R. Wilcox. 1987. People, power plants, and manatees. Sea Frontiers 33(4):263-

269.

Rogillio, H.E., R.T. Ruth, E.H. Behrens, C.N. Doolittle, W.J. Granger, and J.P. Kirk. 2007. Gulf

sturgeon movements in the Pearl River drainage and the Mississippi Sound. No. Amer. J. Fish. Mgt.

27:89-95.

U.S. Army Corps of Engineers. 2006. Draft Biological Assessment: Impacts of USACE Navigational

Projects on the Gulf Sturgeon in Louisiana. New Orleans, LA. 43 pp.

U.S. Fish and Wildlife Service. 2001c. Florida manatee recovery plan. Southeast Region, U.S. Fish and

Wildlife Service, Atlanta, GA. 144 pp. + App.

U.S. Fish and Wildlife Service. 2007. National Bald Eagle Management Guidelines. U.S. Fish and

Wildlife Service. 23 pp.

Vladykov, V.D., and J.R. Greely. 1963. Oder Acipenseroidei. In fishes of the western North Atlantic.

Mem. Sears Found. Mar. Res. 1(3): 24-58.

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. Mgt. Pp. 590-605.

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BLANK

456
Appendix B

U.S. FISH AND WILDLIFE

SERVICE COORDINATION

LETTERS AND REPORT

457

Coordination Letters

459

461
462
463
464
465
466
467
468
469
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United States Department of the Interior

OFFICE OF THE SECRETARY

Office of Environmental Policy and Compliance

1001 Indian School Road NW, Suite 348

Albuquerque, New Mexico 87104

ER 10/479

File 9043.1

June 29, 2010

Joan Exnicios

Chief, Environmental Planning & Compliance Branch

New Orleans District

U.S. Army Corps of Engineers

PO Box 60267

New Orleans, Louisiana 70160-0267

Subject: Draft Supplemental Environmental Impact Statement (DSEIS) for Amite River

Diversion Canal (ARDC) Modification Element of the Section 7006(E)(3)

Ecosystem Restoration Project, Feasibility Study, Louisiana Coastal Area (LCA),

Ascension and Livingston Parishes, LA

Dear Ms. Exnicios:

The U.S. Department of the Interior has reviewed the subject document and offers the following

comments in accordance with provisions of the National Environmental Policy Act (NEPA) of

1969 (83 Stat. 852; 42 U.S.C. 4321 et seq.), the Fish and Wildlife Coordination Act (FWCA, 48

Stat. 401, as amended; 16 U.S.C. 661 et seq.), and the Endangered Species Act of 1973 (87 Stat.

884, as amended, 16 U.S.C. 1531 et seq.).

General Comments on the DSEIS

The DSEIS provides a good description of fish and wildlife resources within the study area, the

purpose and need for the proposed action, program objectives, critical needs and opportunities,

and potential risks and uncertainties. Given the substantial adverse impacts to the project area

wetlands and their associated fish and wildlife resources that are expected to occur under futurewithout-project conditions, the U.S. Fish and Wildlife Service strongly supports authorization

and implementation of the ARDC project, as it would improve environmental conditions through

the creation and/or restoration of swamp habitats. Specifically, the LCA-ARDC project is

designed to establish hydrologic connectivity between the ARDC and the western Maurepas

Swamp. That connectivity would allow the swamp to drain during seasonal low-flow conditions

in the Amite River, and thereby, promote the germination and survival of bald cypress (and other

tree species) seedlings. In addition, nutrients and sediments would be introduced from the

ARDC into the swamp during flood events and from runoff during localized rainfall events.

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Nutrients and sediment delivered to the swamp would improve biological productivity and

reduce the chances of further habitat degradation and swamp loss via conversion to open water.

The FWSs Lafayette Field Office supports implementation of the proposed project and provided

the following fish and wildlife recommendations in our April 2010 Draft FWCA Report:

1. If authorized funding limits for this project are increased the FWS recommends that

Alterative 39 be reconsidered as the potential future Tentatively Selected Plan

(TSP).

2. If a proposed project feature is changed significantly or is not implemented within

one year of the Endangered Species Act consultation letter, we recommend that the

Corps reinitiate coordination with our office to ensure that the proposed project

would not adversely affect any federally listed threatened or endangered species or

their critical habitat.

3. 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).

4. To minimize disturbance to 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 nonnesting 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.

5. Because bald eagles are known to nest within the proposed study area, we

recommend that an evaluation 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 and those results should be forwarded to this office.

6. Land clearing associated with project features should be conducted during the fall

or winter to minimize impacts to nesting migratory birds, when practicable.

7. Further detailed planning of project features (e.g., Design Documentation Report,

Engineering Documentation Report, Plans and Specifications, or other similar

documents) should be coordinated with the FWS and other State and Federal

natural resource agencies, and shall be provided an opportunity to review and

submit recommendations on all the work addressed in those reports.

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8. A report documenting the status of implementation, maintenance and adaptive

management measures should be prepared every 3 years by the managing agency

and provided to the Corps, the FWS, National Marine Fisheries Service, U.S.

Environmental Protection Agency, Louisiana Department of Natural Resources,

Office of Coastal Protection and Restoration, and the Louisiana Department of

Wildlife and Fisheries. That report should also describe future management

activities, and identify any proposed changes to the existing management plan.

Specific comments on the SEIS

Page ES-xv, ES.10 Conclusions and Recommendations, Paragraph 1, Sentence 1  This sentence

should read . . . includes the creation of three conveyance channels. . .

Page 3-9, Table 3.1 Evaluation of Hydrologic Subunits, SE-2 Description  This section states

that although the swamps within SE-2 are hydrologically connected to the Blind River, this area

would benefit from additional freshwater, nutrients, and sediments, as well as flushing of severe

saltwater intrusion events. The FWS recommends describing why such benefits are not currently

being realized (from the existing hydrologic connection to the Blind River) and how additional

benefits would be derived from connecting the area to the ARDC.

Page 3-16, Table 3.2 Management Measures Considered with Screening Results, CS-01 Clearing

and Snagging of Bayou Chene Blanc NE-1/NW-2  The screening result identified does not

address clearing and snagging activities, but rather dredging activities. The FWS, therefore,

recommends revising accordingly.

Page 3-72, Section 3.7 Plan Selection  Tentatively Selected Plan  Table 3.11 depicts the

Project Delivery Teams (PDT) ranking of the Final Array of Alternatives. Because the PDT

ranked Alternatives 39, 36, and 38 higher than Alternative 33, we recommend justifying why

Alternative 33 was selected as the TSP over those higher ranked alternatives.

Page 3-90, Performance Measures for Monitoring, Performance Measure 2b: Number of cypress

and tupelo saplings  Both cypress and tupelo are shade intolerant. The desired outcome should

be revised to accurately depict the limits of this performance measure. Performance of this

measure is dependent on achieving historic hydrologic patterns (extended dry periods) in the

swamp and would be more probable in areas that allow sufficient light (i.e., deteriorated swamp

habitats that are converting to marsh/open water). Conversely, achievement of this measure is

unlikely in healthier portions of the project area.

Page 4-2, Section 4.1.2 Climate, Paragraph 2, Sentence 6  This sentence should read Minimum

and maximum annual rainfall values for Reserve were reported as 34.1 and 84.3 inches,

respectively.

Page 5-1, Section 5.0 Environmental Consequences  The FWS recommends addressing direct,

indirect, and cumulative impacts of the proposed project to the bald eagle and colonial nesting

wading birds in this section. In addition, we recommend including a discussion on how potential

adverse impacts to those species will be avoided.

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Comments on the BA

The Gulf sturgeon is an anadromous fish that occurs in many coastal rivers and streams and

estuarine waters from the Atchafalaya River to the Suwanee River, Florida. In Louisiana, Gulf

sturgeon have been reported at Rigolets Pass, and rivers and lakes of the Lake Pontchartrain

basin and adjacent estuarine areas. The proposed project does not occur within Gulf sturgeon

critical habitat and that species has not been reported within the ARDC. Furthermore, while

there may be minor impacts to Gulf sturgeon prey species those impacts are expected to be

insignificant since only a small fraction of the total ARDC water bottom would be impacted.

Thus, the FWSs Louisiana Field Office concurs with your determination that the proposed

activity is not likely to adversely affect the Gulf sturgeon or its critical habitat.

Federally listed as endangered, West Indian manatees (Trichechus manatus) occasionally enter

Lakes Pontchartrain and Maurepas, including their associated coastal waters and streams, during

the summer months. Manatees, within Louisiana, have also been reported in the Amite, Blind,

Tchefuncte, and Tickfaw Rivers, and in canals within the adjacent coastal marshes, they have

also been occasionally observed elsewhere along the Louisiana coast. According to your BA, all

contract personnel associated with the project would be informed of the potential presence of

manatees and the need to avoid collisions with manatees. Temporary signs would be posted

prior to and during all construction/dredging activities to remind personnel to be observant for

manatees during active construction/dredging operations or within vessel movement zones (i.e.,

work area). In addition, siltation barriers, if used, would be made of material in which manatees

cannot become entangled, and would be properly secured and monitored. If a manatee is sighted

within 100 yards of the active work zone, special operating conditions would be implemented,

including: no operation of moving equipment within 50 feet of a manatee; all vessels would

operate at no wake/idle speeds within 100 yards of the work area; and siltation barriers, if used,

would be re-secured and monitored. Once the manatee has left the 100-yard buffer zone around

the work area on its own accord, special operating conditions are no longer necessary, but careful

observations would be resumed. Accordingly, the FWSs Louisiana Field Office concurs with

your determination that the proposed work is not likely to adversely affect the West Indian

manatee.

No further endangered species consultation will be required for this project unless there are

changes in the scope or location of the work, or construction has not been initiated within 1 year.

If the work has not been initiated within 1 year, follow-up consultation should be accomplished

with the FWSs Louisiana Field Office prior to making expenditures for construction.

We appreciate the opportunity to provide comments on the subject document. If your staff has

additional questions regarding our comments, please contact FWSs Lafayette Field Office

Karen Soileau at (337) 291-3132.

Sincerely,

Stephen R. Spencer

Regional Environmental Officer

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cc: U.S. Environmental Protection Agency, Dallas, TX

Attn: Barbara Keeler

NOAAs National Marine Fisheries Service, Baton Rouge, LA

Attn: Mr. Richard Hartman

Louisiana Department of Wildlife and Fisheries, Baton Rouge, LA

Attn: Mr. Kyle Balkum

Louisiana Department of Wildlife and Fisheries, Natural Heritage Program,

Baton Rouge, LA

Louisiana Office of Coastal Protection and Restoration, Baton Rouge, LA

Attn: Renee Sanders

475

Coordination Act Report

477

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480
DRAFT

FISH AND WILDLIFE COORDINATION ACT REPORT

ON

LOUISIANA COASTAL AREA - AMITE RIVER DIVERSION

CANAL MODIFICATION ELEMENT OF THE SECTION 7006(E)(3)

ECOSYSTEM RESTORATION PROJECTS STUDY

Submitted To

New Orleans District

U.S. Army Corps of Engineers

and

Office of Coastal Protection and Restoartion

Prepared by

Karen Soileau

Fish and Wildlife Biologist

U.S. Fish and Wildlife Service

Ecological Services

Lafayette, Louisiana

April 2010

481

TABLE OF CONTENTS

INTRODUCTION ...........................................................................................................................1

DESCRIPTION OF THE STUDY AREA ......................................................................................1

FISH AND WILDLIFE RESOURCES ...........................................................................................4

Major Habitat Types ............................................................................................................4

Cypress/Tupelo Swamps..........................................................................................4

Bottomland Hardwoods ...........................................................................................5

Open Water ..............................................................................................................5

Fresh Marsh .............................................................................................................6

Developed Areas......................................................................................................6

Fishery Resources ................................................................................................................6

Wildlife Resources...............................................................................................................7

Invasive Species...................................................................................................................7

Threatened and Endangered Species ...................................................................................8

West Indian Manatee ...............................................................................................8

Gulf Sturgeon...........................................................................................................8

Species of Special Interest ...................................................................................................9

Bald Eagle................................................................................................................9

Colonial Nesting Birds...........................................................................................10

Refuges and Wildlife Management Areas .........................................................................10

EVALUATION METHODOLOGY .............................................................................................10

FUTURE WITHOUT PROJECT FISH AND WILDLIFE RESOURCES ...................................13

DESCRIPTION OF NATIONAL ECOSYSTEM RESTORATION PLAN.................................13

EVALUATION OF NATIONAL ECOSYSTEM RESTORATION PLAN.................................15

DESCRIPTION OF TENTATIVELY SELECTED PLAN ..........................................................16

EVALUATION OF TENTATIVELY SELECTED PLAN ..........................................................18

FISH AND WILDLIFE CONSERVATION AND MITIGATION MEASURES ........................18

SERVICE POSITION AND RECOMMENDATIONS ................................................................18

LITERATURE CITED ..................................................................................................................20

APPENDIX A............................................................................................................................. A-1

APPENDIX B ..............................................................................................................................B-1

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INTRODUCTION

The Louisiana Coastal Area – Amite River Diversion Canal (LCA-ARDC) Modification

Integrated Feasibility Report and Environmental Impact Statement (EIS) was prepared by the

U.S. Army Corps of Engineers (USACE), New Orleans District, in partnership with the

Louisiana Office of Coastal Protection and Restoration, under the authority of Title VII of the

Water Resources Development Act (WRDA) of 2007. This authorization was recommended by

the Chief of Engineer’s Report, dated January 31, 2005. That report recommended projects and

features in the interest of hurricane protection, prevention of salt water intrusion, preservation of

fish and wildlife, prevention of erosion, and related water resources purposes. One

recommended project was the modification of the ARDC.

The LCA-ARDC project is designed to establish hydrologic connectivity between the ARDC and

the western Maurepas Swamp. That connectivity would allow the swamp to drain during

seasonal low-flow conditions in the Amite River, and thereby, promote the germination and

survival of bald cypress (and other tree species) seedlings. In addition, nutrients and sediments

would be introduced from the ARDC into the swamp during flood events and from runoff during

localized rainfall events. Nutrients and sediment delivered to the swamp would improve

biological productivity and reduce the chances of further habitat degradation and swamp loss via

conversion to open water.

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 improve the

proposed restoration measures. 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 draft FWCA Report is being provided to the Louisiana

Department of Wildlife and Fisheries (LDWF) and the National Marine Fisheries Service

(NMFS); their comments will be incorporated into the final report.

DESCRIPTION OF THE STUDY AREA

In the 1950s, the USACE, in an effort to relieve flooding along the upper Amite River,

constructed the ARDC in order to facilitate the flow of water from the Amite River to Lake

Maurepas. The 10 mile long canal is 350 feet wide and was dug to a depth of -25 feet. The

LCA-ARDC study area (Figure 1) is located in LCA Subprovince 1 (USACE 2004) and is

situated along the ARDC in Ascension and Livingston parishes, in the vicinity of Head of Island,

Louisiana. The study area is bounded to the north by the old channel of the Amite River, Old

River, Chinquapin Canal and Bayou Chene Blanc; to the east by the Blind River; to the south by

the Petite Amite River and the New River Canal; and to the west by the Sevario Canal,

Ascension Parish flood protection levees, and the Laurel Ridge Canal.

Historically, hydrologic conditions within the LCA-ARDC study area were dominated in the

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north and west by the Amite River, in the south by overbank flow from the Mississippi River,

and in the east by tidal influence from Lake Maurepas. Periodic flooding of the Amite River

and/or Mississippi River resulted in the inundation of the study area. Flooding occurred

annually, with peak water elevations in the spring or early summer. As floodwaters receded,

surface waters in the study area were conveyed eastward via sheet flow to Bayou Chene Blanc or

Blind River, then to Lake Maurepas.

The construction of flood control projects within the LCA-ARDC study area, primarily the

ARDC component of the Amite River and Tributaries (AR&T) project, together with other land

use practices, such as land development and logging, have significantly altered the hydrologic

regime of the study area. River channelization and levee construction reduced overbank flooding

in the study area, which in turn reduced the influx of floodwaters bearing high volumes of

nutrients and sediment that are essential for biomass production and soil accretion. In addition,

the placement of dredged material as berms along either side of the ARDC disrupted sheet flow

within the LCA-ARDC study area and formed topographic high points (ridges) that prevented

the drainage of bald cypress-tupelo swamps into the ARDC during low surface flow intervals

(USACE 2004). This activity, in conjunction with other activities, such as construction of the

railroad grade that traverses the eastern study area from north to south, permanently impounded

bald cypress-tupelo swamp habitat within the study area. Those impoundments have contributed

to decreased water quality and increased cypress and tupelo seedling mortality, which has

resulted in increased habitat conversion from cypress swamp to open water.

Impoundment is particularly pronounced within the eastern portion of the LCA-ARDC study

area, i.e., NE-1 and NE-2 (Figure 1). Specifically, during a recent study, water levels within the

swamp habitat along the left descending bank of the ARDC never receded below 2.2 feet above

mean sea level (msl), although canal water levels receded below that level (Shaffer et al., 2006).

Swamp impoundment is not as evident within the western portion of the LCA-ARDC study area.

Installation of drainage culverts, construction of several gaps in the dredge material berms, and

the confluence of Bayou Pierre with the ARDC in that area provide for hydrologic exchange

between the diversion canal and the adjacent swamps.

Subsidence and salinity increases have also contributed to swamp ecosystem degradation in the

LCA-ARDC study area. Land elevations decrease from subsidence, which may be caused by

compaction, oxidation, and consolidation of sediments, faulting, groundwater depletion, or

decreased organic deposition as a result of decreased vegetation biomass production; while land

elevations increase as a result of sediment accretion, from direct sediment input from riverine

sources or from organic vegetation deposition. The soil characteristics of the western Maurepas

Swamp indicate a lack of riverine influence as evidenced by high soil organic matter content and

low bulk density values (DeLaune et al. 1979, Hatton 1983, Messina and Conner 1998).

Consequently, soil building within the Maurepas Swamp is almost exclusively a result of organic

productivity (Shaffer et al. 2001, 2003, 2006, Rybczyk et al. 2002, Roberts 1985). In the

swamps adjacent to the ARDC, productivity is substantially depressed compared to normal

conditions (Coastal Wetlands Planning, Protection and Restoration Act [CWPPRA] Task Force

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Figure 1. Study Area and Subunits.

Figure 1. Study Area and Subunits

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2002). Subsidence in the LCA-ARDC study area and vicinity is classified as intermediate, at

about 1.1-2.0 feet per century (LCA 2004). With minimal soil building and moderately high

subsidence, there has been a net lowering of ground surface elevation, doubling flood frequency

over the last four decades (Thompson 2000), so that the swamps are now persistently flooded.

Saltwater intrusion has increased in this general area, partly due to net subsidence and the lack of

riverine freshwater inputs. Salinities as low as three parts per thousand (ppt) can reduce growth

of both bald cypress and water tupelo saplings (Pezeshki et al. 1990). Salinity, combined with

flooding stress, can substantially reduce bald cypress growth. Consequently, salinity

significantly contributes to swamp deterioration, particularly combined with stressors such as

flooding and herbivory.

Storm surges from Lake Maurepas caused by tropical cyclones also exert a stochastic but severe

stress on the swamp habitat through salinity spikes in swamp surface waters. Dredged material

berms prevent higher salinity water from being flushed out of the system (CWPPRA Task Force

2002). Storm surge waters remain in the impounded swamps of the LCA-ARDC study area

cumulatively increasing salinities in impounded waters and soils.

FISH AND WILDLIFE RESOURCES

The purpose of this section is to describe the principal fish and wildlife resources of the study

area, and to establish their significance. Several key habitat types are described, followed by

qualitative descriptions of important fish and wildlife.

Major Habitat Types

Cypress/Tupelo Swamps

The LCA-ARDC study area contains approximately 27,984 acres; the majority of which is

dominated by bald cypress/tupelo swamp habitat. About 18,204 acres of that habitat type are

presently impounded to various extents within the study area; that persistent flooding has

resulted in the impairment of cypress/tupelo seedling establishment/regeneration (CWPPRA

Task Force 2002). Cypress/tupelo regenerates well when the seedbed is moist but not flooded

during the time period of seed germination and seedling establishment. Cypress/tupelo seeds

cannot germinate in standing water, and seedlings must grow tall enough during dry periods for

their crowns to extend above the water surface to survive flooding during the growing season.

Excessive flooding will reduce regeneration even though overstory trees may still be thriving.

Ultimately, the lack of regeneration due to prolonged inundation will eliminate forest cover,

resulting in the conversion of swamp habitat to open water over time (CWPPRA Task Force

2002). In addition, saltwater intrusion from storm events has stressed the swamp habitat along

the Blind River.

Cypress swamps in the project area provide substantial fish and wildlife values. Wildlife species

typical of cypress swamps include green tree frog, bullfrog, mud and musk turtles, American

alligator, various species of water snakes, anhinga, barred owl, northern parula, great blue heron,

great egret, white ibis, and mink. Often surrounding backwater lakes, these areas also provide

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essential habitat for aquatic species when inundated.

In addition to bald cypress and water tupelo, Drummond red maple, green ash, and various oak

species are also found in the cypress/tupelo swamp habitat within the LCA-ARDC study area,

with Drummond red maple and green ash comprising sub-dominant midstory species (Conner

and Day 1976; Hoeppner 2008; Shaffer et al. 2003). Scrub species, including black willow, wax

myrtle, and common buttonbush are sporadically present, particularly in areas with diminished

canopy cover caused by impaired health or mortality of overstory species. Shrub-scrub swamps

provide important nesting habitat for colonial wading birds as well as various species of aquatic

wildlife.

Bottomland Hardwoods

Bottomland hardwoods are present along several ridge remnants that run through the LCAARDC study area. These ridges are mostly near the mid-point of the east-west stretch of the

ARDC. Dominant tree species in those areas include Drummond red maple, green ash, laurel

oak, water oak, sweet gum, sugarberry, American elm, and Chinese tallow. The areas between

the ridges and the swamp show a transition in species including green ash, Drummond red

maple, black willow, bald cypress, and water tupelo. Wax myrtle, rough-leaf dogwood, black

willow, Chinese tallow, Chinese privet, yaupon, and deciduous holly typically dominate the

shrub stratum. Vines such as poison ivy, greenbriars, pepper vine, and trumpet creeper are

present. In addition, an old railroad grade and several earthen levees run through the LCAARDC study area with similar habitats.

Bottomland hardwood forests typically provide high wildlife habitat values to a variety of

species, including amphibians such as the Gulf coast toad and Cope’s gray tree frog; reptiles

such as the copperhead and green anole; many species of birds, including wood duck, barred

owl, pileated woodpecker, red-shouldered hawk, Acadian flycatcher, Swainson's Warbler and

northern parula; and mammals including white-tailed deer, swamp rabbit, gray fox, bobcat,

raccoon, opossum, and squirrels. In addition to terrestrial wildlife, many species of fish utilize

flooded bottomland hardwoods as well; some species are specifically adapted for spawning in

these backwater flood plains.

Open Water

Open water areas are distributed throughout the LCA-ARDC study area and include the ARDC;

the Amite, Petite Amite, and Blind Rivers; Bayous Pierre and Chene Blanc; and the Choupique

Canal. Submerged aquatic vegetation communities within the LCA-ARDC study area are

largely confined to areas of higher flow. This includes natural waterways and natural cuts into

the swamp interior. Shallow water habitats within the LCA-ARDC study area that have

insufficient flow have become choked with floating vegetation, greatly limiting light penetration

within the water column.

In their 2006 Water Quality Integrated Report, the Louisiana Department of Environmental

Quality indicated that water within the study area supports the designated standards for primary

and secondary contact recreation, but does not support those standards for fish and wildlife

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propagation. Suspected sources of impairment include mercury, total phosphorus, chloride,

excessive nutrient levels, siltation, and low levels of dissolved oxygen.

Fresh Marsh

There are approximately 249 acres of fresh marsh within the LCA-ARDC study area. Shaffer et

al. (2003) have shown that many of the marshes within the Maurepas Swamp exist as a

transitional habitat as swamps are converting to open water areas over time. Those swamp

habitats are being replaced by marsh and open water due to a number of factors including salt

water intrusion (associated with hurricanes and rising sea levels), altered hydrology,

impoundments, subsidence, and herbivory (Keddy et al. 2007).

Developed Areas

Developed areas comprise approximately 281 acres within the LCA-ARDC study area. Urban

areas are primarily confined to the dredged material berms lining the ARDC adjacent to LA-22,

and the right descending bank of the Amite River in the northwestern portion of the LCA-ARDC

study area. Barren lands make up a small percentage of the LCA-ARDC study area and may

include strip mines, quarries, and gravel pits. Agricultural croplands or grasslands make up

approximately 469 acres of the LCA-ARDC study area and appear to be restricted to livestock

pasture. These pastures are located in isolated pockets along the lower Amite River and LA-22

in the western portion of the study area.

Fishery Resources

Construction of the ARDC and dredged material berms have impeded exchange of organisms

and water between the swamp and the ARDC. Accordingly, the study area is expected to

provide low- to moderate-value habitat for some recreationally important fishes and shellfishes.

Freshwater sport fishes likely present include white crappie, bluegill, warmouth, channel catfish,

and blue catfish. Other fishes likely present include yellow bullhead, freshwater drum, bowfin,

carp, buffaloes, and gars. In addition, the waterbodies and wetlands of the LCA-ARDC study

area provide nursery and foraging habitats supportive of a variety of fishery species, some of

which may serve as prey for other fish species.

Lantz (1970) sampled fish within the Amite River; primarily freshwater species were collected,

although a few transient marine species were also collected or reported. Species collected

included blue catfish, gizzard shad, spotted gar, freshwater drum, channel catfish, striped mullet,

and largemouth bass. Laiche (1980) also sampled fish within the Amite River. The most

abundant species collected were blacktail shiner, bullhead minnow, mosquitofish, longear

sunfish, mimic shiner, blackstripe topminnow, bluegill, and longnose shiner.

Watson et al. (1981) collected 57 species of fish in the Blind River, including 43 freshwater

species, 12 estuarine species, and two diadromous species. The authors suggested the confluence

of the ARDC was a point of separation between the upper and lower reaches of Blind River. The

lower Blind River had the greatest species diversity, primarily due to the presence of estuarine

species. The low concentrations of dissolved oxygen above the ARDC could be an important

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limiting factor in the distribution of fish.

Aquatic and wetland habitats in the LCA-ARDC study area also provide foraging and nursery

habitat for a few economically important marine fishery species that use freshwater habitats in

this area. The species expected to be found in the LCA-ARDC study area include striped mullet

and Gulf menhaden.

Wildlife Resources

The coastal marshes and forested wetlands of the Lake Pontchartrain Basin have been identified

by the North American Waterfowl Management Plan (NAWMP), Gulf Coast Joint Venture

(GCLV): Mississippi River Coastal Wetlands Initiative as a key waterfowl wintering area. The

Gulf Coast is the terminus of the Central and Mississippi Flyways and is therefore one of the

most important waterfowl areas in North America, providing both wintering and migration

habitat for significant numbers of the continental duck and goose populations that use both

flyways. The Mississippi River Coastal Wetlands Initiative area is dominated by coastal marsh,

forested swamps, and seasonally flooded bottomland hardwoods that provide habitat for several

species of wintering waterfowl. Wood ducks are the primary waterfowl species in forested

wetlands, while other ducks (e.g., mallard, American widgeon, gadwall, blue- and green-winged

teal, Northern shovelers, ring-necked ducks, and lesser scaup) use those forested habitats to a

lesser degree.

Strategies to achieve the goals and objectives of the GCJV include but are not limited to: 1)

maintaining the existing functions and values of those habitats and preventing additional losses

and degradation of those wetlands and 2) modifying existing dredged material berms and canals

to restore hydrology (Wilson et al. 2002). Numerous other game birds are present in or adjacent

to the study area, including American coot, rails, gallinules, common snipe, and American

woodcock. Non-game bird species also utilize the study area marshes, including least bittern,

pied-billed grebe, black-necked stilt, American avocet, killdeer, black-bellied plover, willet, and

various species of sandpipers, gulls, and terns. The study area supports many resident and

transient hawks and owls including red-shouldered hawk, barn owl, common screech owl, great

horned owl, and barred owl. Winter residents include red-tailed hawk, northern harrier, and

American kestrel, while the Mississippi kite, swallow-tailed kite and broad-winged hawk are

common summer residents. In addition, the project area supports many species of resident and

migratory passerine birds. Some neo-tropical migrants that are currently experiencing a

population decline (e.g., white-eyed vireo, northern parula) are dependent on large forested

acreage to successfully reproduce. Also, present are cuckoos, swifts, hummingbirds,

nighthawks, woodpeckers, and the belted kingfisher.

Invasive Species

Within the LCA-ARDC study area invasive mammal species present include nutria and feral

hogs. Invasive plant species present within that area include: water hyacinth, alligator weed,

hydrilla, common salvinia, giant salvinia, variable-leaf milfoil, Chinese tallow, and Chinese

privet. Those species displace native aquatics and degrade water and/or habitat quality. In

addition, Chinese tallow is tolerant to flooding and salt stress and can establish self-replacing

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monocultures that provide less foraging value to migrating birds and interrupt the natural

succession of woody species (Louisiana Coastal Protection and Restoration 2008).

Threatened and Endangered Species

West Indian Manatee

Federally listed as an endangered species, West Indian manatees (Trichechus manatus)

occasionally enter Lakes Pontchartrain and Maurepas, and associated coastal waters and streams

during the summer months (i.e., June through September). Manatee occurrences appear to be

increasing, and they have been regularly reported in the Amite, Blind, Tchefuncte, and Tickfaw

Rivers, and in canals within the adjacent coastal marshes of Louisiana. 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.

All contract personnel associated with the project should be informed of the potential presence of

manatees and the need to avoid collisions with manatees, which are protected under the Marine

Mammal Protection Act of 1972 and the Endangered Species Act of 1973. All construction

personnel are responsible for observing water-related activities for the presence of manatee(s).

Temporary signs should be posted prior to and during all construction/dredging activities to

remind personnel to be observant for manatees during active construction/dredging operations or

within vessel movement zones (i.e., work area), and at least one sign should be placed where it is

visible to the vessel operator. Siltation barriers, if used, should be made of material in which

manatees could not become entangled, and should be properly secured and monitored. If a

manatee is sighted within 100 yards of the active work zone, special operating conditions should

be implemented, including: no operation of moving equipment within 50 feet of a manatee; all

vessels should operate at no wake/idle speeds within 100 yards of the work area; and siltation

barriers, if used, should be re-secured and monitored. Once the manatee has left the 100-yard

buffer zone around the work area on its own accord, special operating conditions are no longer

necessary, but careful observations would be resumed. Any manatee sighting should be

immediately reported to the Service’s Lafayette, Louisiana Field Office (337/291-3100) and the

Louisiana Department of Wildlife and Fisheries, Natural Heritage Program (225/765-2821).

Gulf Sturgeon

The Gulf sturgeon (Acipenser oxyrhynchus desotoi), 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 Suwannee River, Florida. In Louisiana, Gulf

sturgeon have been reported at Rigolets Pass, rivers and lakes of the Lake Pontchartrain 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. Sturgeon

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

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negatively affected this species.

On March 19, 2003, the Service and the National Marine Fisheries Service (NMFS) 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. The proposed project, however, does

not occur within nor would it impact designated Gulf sturgeon critical habitat.

The Corps is responsible for determining whether the selected alternative is likely (or not likely)

to adversely affect any listed species and/or critical habitat, and for requesting the Service’s

concurrence with that determination. If the Corps determines, and the Service concurs, that the

selected alternative is likely to adversely affect listed species and/or critical habitat, a request for

formal consultation in accordance with Section 7 of the ESA should be submitted to the Service.

That request should also include the Corps’ rationale supporting their determination.

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 is one active bald eagle nest that is known to exist within the

proposed project area, however, other nests may be present that are not currently listed in the

database maintained by the Louisiana Department of Wildlife and Fisheries.

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

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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.

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

There are no U.S. Fish and Wildlife Service National Wildlife Refuges located within the LCAARDC study area. A portion of the state-operated Maurepas Swamp Wildlife Management Area

is located within that study area. Please contact the Louisiana Department of Wildlife and

Fisheries in Baton Rouge, Louisiana, (225/765-2360) for their comments regarding potential

project impacts to this area.

EVALUATION METHODOLOGY

Evaluation of project-related impacts on fish and wildlife resources was aided by use of the

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Wetland Value Assessment (WVA) methodology developed for the evaluation of proposed

CWPPRA projects (Louisiana Coastal Wetlands Conservation and Restoration Task Force

[LCWCRTF] 2006). The WVA methodology is similar to the Service’s Habitat Evaluation

Procedures (HEP), in that habitat quality and quantity are measured for baseline conditions and

predicted for future without-project (FWOP) and future with-project (FWP) conditions. Separate

habitat assessment models were used, including the Swamp and Bottomland Hardwood

Community Models. Instead of the species-based approach of HEP, each 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 WVA methodology was initially developed in 1991 by the CWPPRA Environmental Work

Group (LCWCRTF 2006). Initially, emergent marsh habitat models were developed for fresh,

intermediate, brackish and saline marsh types. Subsequently, models were also developed for

swamps, barrier islands, barrier headlands, and coastal forested ridges. The habitat variablehabitat suitability relationships within the WVA models have not been verified by field

experiments or validated through a rigorous scientific process. However, the variables were

originally derived from HEP suitability indices taken from species models for species found in

that habitat type. It should also be noted that some aspects of the WVA have been defined by

policy and/or functional considerations of CWPPRA. However, habitat variable-habitat

suitability relationships are, in most cases, supported by scientific literature and research

findings. In other cases, best professional judgment by a team of fisheries biologists, wildlife

biologists, ecologists, and university scientists may have been used to determine certain habitat

variable-habitat suitability relationships. In addition, the WVA models have undergone a

refinement process and habitat variable-habitat suitability relationships, HSIs, and other model

aspects are periodically modified as more information becomes available regarding coastal fish

and wildlife habitat suitability, coastal processes, and the efficacy of restoration projects being

evaluated.

The WVA models assess the suitability of each habitat type for providing resting, foraging,

breeding, and nursery habitat to a diverse assemblage of fish and wildlife species. This

standardized, multi-species, habitat-based methodology facilitates the assessment of projectinduced impacts on fish and wildlife resources. The CWPPRA swamp WVA model used

consists of four variables: 1) stand structure; 2) stand maturity; 3) water regime; and 4) mean

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high salinity during the growing season. The bottomland hardwood WVA model consists of

seven variables: 1) tree species association; 2) stand maturity; 3) understory/midstory; 4)

hydrology; 5) size of contiguous forested area; 6) suitability and traversability of surrounding

land uses; and 7) disturbance.

Using the WVA methodology, impact assessments were conducted by the Habitat Evaluation

Team (HET), which included representatives from the Service, the Corps, Office of Coastal

Protection and Restoration, GEC, Southeast Louisiana University, and Taylor Engineering. To

assess impacts the HET used habitat information collected during June and July 2009 field

inspections, surveys, expert opinions, knowledge of the area, experience with similar projects,

Digital Ortho-quarter Quadrangle aerial photographs (DOQQ), and hydraulics and hydrology

modeling information.

Those elements were used in conjunction with the above-discussed mathematical models to

compute an HSI value for each target year (TY). Target years identified within the LCA-ARDC

WVA model runs include: TY0, TY1, TY10, TY25, and TY50.

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 seven alternatives within the LCA-ARDC Final Array were evaluated: Alternative 33 (NE1/NE-2), Alternative 34 (SE-1/SE-2), Alternative 35 (SE-1), Alternative 36 (NE-1/NE-2, SE1/SE-2), Alternative 37 (SE-1/SE-2, SE-1), Alternative 38 (NE-1/NE-2, SE-1), and Alternative

39 (NE-1/NE-2, SE-1/SE-2 – All Subunits Combined). Prior to running the WVA analysis, the

benefit areas associated with each alternative were designated as either primary impact areas or

secondary impact areas. For purposes of the WVA, the Service assumed that the primary impact

areas would receive the most benefits from freshwater flows, nutrients, and sediments, while the

secondary impact areas would receive lesser benefits.

Subsequent to the mapping of primary and secondary impact areas for each alternative, WVAs

were run for each habitat type (i.e., degraded swamp/fresh marsh, 10 years to convert to marsh,

20-30 years to convert to marsh, and 30-50 years to convert to marsh) present within those areas.

Once benefits were calculated, adverse temporary and permanent impacts to swamp and

bottomland hardwood habitats associated with construction of the bank openings, conveyance

channels, and dredged material placement were calculated. The change in AAHUs for each

FWP scenario, compared to FWOP project conditions, provides a measure of anticipated

impacts. A net gain in AAHUs indicates that the project is beneficial to the habitat being

evaluated; a net loss of AAHUs indicates that the project is damaging to that habitat type.

The WVA initial analysis was completed on the primary and secondary impact areas for all

alternatives under the low sea level rise (SLR) scenario. As requested by the Corps, additional

WVAs were later run to quantify impacts under the intermediate and high SLR scenarios for the

Tentatively Selected Plan and the National Ecosystem Restoration Plan. A combined total of

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168 WVA evaluations were completed.

The Project Information Sheet (including assumptions used by the HET) and the WVA summary

sheet for the LCA-ARDC project are presented in Appendix A and B, respectively. The

complete WVA analysis can be obtained from the Service’s Lafayette, Louisiana Ecological

Services Office upon request.

FUTURE WITHOUT-PROJECT FISH AND WILDLIFE RESOURCES

Under future without-project conditions, the current problems associated with altered hydrology

are expected to continue. The swamp habitat surrounding the ARDC will likely continue to

degrade, resulting in the eventual conversion from a freshwater swamp to open water. The lack

of hydrologic connectivity would result in the continued impoundment of the project-area

swamp, with an associated reduction in canopy cover, degradation of water quality, and

transition of swamp habitat to marsh, with the eventual conversion to open-water habitat. Storm

surges from tropical cyclone events would increase salinity levels and the frequency of saltwater

inundation is expected to increase with relative sea level rise (RSLR).

The lack of freshwater, sediments, and nutrients would continue to reduce tree vigor and growth,

increase tree mortality, increase the presence of invasive species, and reduce ecological

functions. In addition, the assumed RSLR, would exacerbate swamp degradation in the future.

The anticipated conversion of swamp habitats to marsh and open water would result in the loss

of wetland values and functions. While the Service recognizes the ecological importance of

freshwater marshes, most of the marshes present within the LCA-ARDC study area are present

as a transitional habitat, as swamps convert to open water, and are the result of habitat

deterioration and conversion, rather than healthy swamp/marsh interfaces. Keddy et al. (2007)

reports that the vast majority of the Maurepas Swamp is typical of swamps identified as either

nutrient poor and stagnant or near-continuously flooded. Flood durations in the Maurepas

Swamp have doubled, on average, over the past half-century (Thomson et al. 2002). The

flooding and impoundment within the study area prevents seed germination and recruitment and,

as a result, swamps are converting to marsh and open water.

Keddy et al. (2007) identify priority actions for habitat restoration within the Maurepas Swamp.

One such recommendation addresses the re-establishment of sheet flow via removal or gapping

of dredged material berms and road and railroad beds. They explain that sheet flow (or shallow

water flow over the surface of the soil) was, most likely, the principle way in which water and

nutrients moved through this system. Now, however, the presence of man-made hydrologic

barriers impedes sheet flow. Canals decrease overbank flooding and accelerate the flow of

water, sediment, and nutrients out of the area, while dredged material berms and other such manmade features block sheet flow. Implementation of the proposed project would restore an

historic ecosystem and increase the fish and wildlife habitat values of the project area.

DESCRIPTION OF NATIONAL ECOSYSTEM RESTORATION PLAN

Alternative 39 (Figure 2) has been identified as the NER and the best plan for ecosystem

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Figure 2. Alternative 39

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restoration in the study area. That plan includes three areas for restoration in the final array,

including two that have a critical need, and have begun converting from swamp to marsh, and a

third less critical area that is expected to begin conversion in the next 20-30 years. Due to

funding limitations and the risk of losing authorization, however, Alternative 39 has not been

designated as the tentatively selected plan (TSP).

Features of Alternative 39 include:

• Three dredged material bank openings and three bifurcated conveyance channels in

the north bank of the ARDC in NE-2 with the westernmost cut in the north bank of

the ARDC also extending through the railroad grade into NE-1 to add connectivity

between NE-1 and NE-2.

• One dredged material bank opening and one bifurcated conveyance channel in the

south bank of the ARDC in SE-1 with the conveyance channel extending through the

railroad grade into SE-1 to add connectivity between SE-1 and SE-2, and the ARDC.

• One opening and one conveyance channel in the south bank of the ARDC in SE-1.

• Dredged material (9.9 acres) from the bank openings and the conveyance channel

would be sidecast on both sides of the proposed channel. Gaps would be left in the

disposal berms so sheet flow is not reduced.

• Three cuts would be created in the railroad grade to improve sheet flow. One cut

would be approximately 0.9 miles north of the ARDC. The second cut would be

approximately 0.9 miles south of the ARDC. The third cut would be approximately

two miles south of the ARDC.

• Vegetative plantings of bottomland hardwood/swamp tree species on 9.9 acres of

dredged material berms.

• Vegetative plantings of swamp tree species within 925 acres of the swamp floor.

All excavation through the dredged material berms, as well as the conveyance channels through

the swamp, were designed to mimic natural, existing cuts within the study area, which have been

determined to be self-maintaining. Several existing channels were surveyed for depth,

dimension, and profile.

The material dredged from the existing berms would be placed along the swamp-side of the

excavated cut as new bottomland hardwood habitat. All material dredged during construction of

the conveyance channels would be placed along the channels, with gaps included, to allow

sufficient sheet flow to be conveyed from the swamp.

EVALUATION OF NATIONAL ECOSYSTEM RESTORATION PLAN

Alternative 39 includes all of the most critical areas within the Maurepas Swamp basin,

establishes the greatest amount of hydrologic connectivity of all of the alternatives, is costeffective while providing the most benefits, and is a best-buy plan. Accordingly, the Service

fully supports Alternative 39 as the NER plan and believes it best represents the long term

restoration need for the area.

The WVA evaluations conducted on all alternatives within the final array show that the highest

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net benefits to fish and wildlife habitats occur with implementation of Alternative 39.

Specifically, the WVA analysis indicates that the NER for the LAC-ARDC project would result

in net gains of 1,602, 1,516, and 1,452 AAHUs under the low, intermediate, and high SLR

scenarios, respectively.

Swamp habitat for fish and wildlife species would be restored, mimicking as closely as possible,

conditions which occurred historically in the area. Implementation of Alternative 39 would

restore the hydrologic connectivity between NE-1, NE-2, SE-1, and SE-2 within the ARDC.

That alternative would improve the hydrologic connectivity between the ARDC and

approximately 3,881 acres in both the primary and secondary impact areas, restore

approximately 290 acres of swamp, and create approximately 9.9 acres of upland habitat from

dredged material placement. Restored hydrologic connections would: 1) increase the nutrient

and sediment input to approximately 1,515 acres within the primary impact area, 2) increase

acreage of high-quality swamp habitats used by fish and wildlife for shelter, nesting, feeding,

roosting, cover, nursery, and other life requirements, and 3) increase vegetative growth and

productivity. In addition, when compared to the future without project scenario, implementation

of this alternative would significantly reduce the likelihood of 3,881 acres of existing swamp

habitat converting to marsh and eventual open water habitat over the life of the project.

DESCRIPTION OF TENTATIVELY SELECTED PLAN

Because the NER plan (Alternative 39) cannot be constructed within the currently authorized

cost cap, Alternative 33 (Figure 3) was chosen as the TSP.

Alternative 33 includes:

• Three dredged material bank openings and three bifurcated conveyance channels in

the north bank of the ARDC in NE-2 with the westernmost channel in the north bank

of the ARDC also extending through the railroad grade into NE-1 to add connectivity

between NE-1, NE-2, and the ARDC.

• Dredged material (5.0 acres) from the bank openings and the conveyance channel

would be sidecast on both sides of the proposed channel. Gaps will be left in the

disposal berms so sheet flow is not reduced.

• One cut would be created in the railroad grade approximately 0.9 miles north of the

ARDC to improve sheet flow.

• Vegetative plantings of bottomland hardwood/freshwater swamp tree species on

5.0 acres of dredged material berms.

• Vegetative plantings of freshwater swamp tree species within 438 acres of the swamp

floor.

All excavation through the dredged material berms, as well as the conveyance channels through

the swamp, were designed to mimic natural, existing cuts within the study area, which have been

determined to be self-maintaining. Several existing channels were surveyed for depth,

dimension, and profile.

The material dredged from the existing berms would be placed along the swamp-side of the

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Figure 3. Alternative 33

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excavated cut as new bottomland hardwood habitat. All material dredged during construction of

the conveyance channels would be placed along the channels, with gaps included, to allow

sufficient sheet flow to be conveyed from the swamp.

EVALUATION OF TENTATIVELY SELECTED PLAN

Alternative 33 addresses the most-highly degraded portion of the study area (NE-2), is

considered cost effective, and can be implemented within the current cost cap. Implementation

of that alternative, however, would not address the restoration needs within SE-1 and SE-2.

Implementation of Alternative 33 would, therefore, result in similar benefits as expected under

Alternative 39, but to a lesser degree. Specifically, Alternative 33 would improve the hydrologic

connectivity between the ARDC and approximately 1,602 acres in both the primary and

secondary impact areas, restore approximately 144 acres of swamp, and create approximately 5.0

acres of upland habitat from dredged material placement. The WVA analysis indicates that the

TSP for the LAC-ARDC project would result in net gains of 679, 640, and 610 AAHUs under

the low, intermediate, and high SLR scenarios, respectively.

FISH AND WILDLIFE CONSERVATION AND MITIGATION MEASURES

Swamp habitats are considered by the Service to be aquatic resources of national importance due

to their increasing scarcity and high habitat value for fish and wildlife within Federal trusteeship

(i.e., migratory waterfowl, wading birds, other migratory birds, threatened and endangered

species, and interjurisdictional fisheries). Because of the Services’ close coordination with the

USACE on this project, and because the project is expected to have an overall benefit to the

LCA-ARDC study area, the Service has no conservation measures to offer at this time.

SERVICE POSITION AND RECOMMENDATIONS

The TSP will benefit the fish and wildlife resources of the LCA-ARDC area by providing

freshwater, nutrients, and sediments to the study area thus facilitating sediment deposition,

increase organic production, increase biological productivity, and reduce conversion of swamp

habitat to open water. Approximately 679 AAHUs and 1,602 net acres of swamp habitats would

benefit by the proposed project at the end of the project life. The Service supports

implementation of Alternative 33 provided the following fish and wildlife recommendations are

implemented concurrently with project implementation:

1. If authorized funding limits for this project are increased the Service recommends that

Alterative 39 be reconsidered as the potential future TSP.

2. If a proposed project feature is changed significantly or is not implemented within one

year of the Endangered Species Act consultation letter, we recommend that the Corps

reinitiate coordination with our office to ensure that the proposed project would not

adversely affect any Federally listed threatened or endangered species or their critical

habitat.

3. Avoid adverse impacts to bald eagle nesting locations and wading bird colonies through

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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).

4. To minimize disturbance to 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.

5. Because bald eagles are known to nest within the proposed study area, we recommend

that an evaluation 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 and

those results should be forwarded to this office.

6. Land clearing associated with project features should be conducted during the fall or

winter to minimize impacts to nesting migratory birds, when practicable.

7. Further detailed planning of project features (e.g., Design Documentation Report,

Engineering Documentation Report, Plans and Specifications, or other similar

documents) should be coordinated with the Service and other State and Federal natural

resource agencies, and shall be provided an opportunity to review and submit

recommendations on the all work addressed in those reports.

8. A report documenting the status of implementation, maintenance and adaptive

management measures should be prepared every three years by the managing agency and

provided to the Corps, the Service, National Marine Fisheries Service, U.S.

Environmental Protection Agency, Louisiana Department of Natural Resources, Office of

Coastal Protection and Restoration, and the Louisiana Department of Wildlife and

Fisheries. That report should also describe future management activities, and identify

any proposed changes to the existing management plan.

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LITERATURE CITED

Coastal Wetlands Planning, Protection, and Restoration Act Task Force. 2002. 12th Priority

Project List Report (Appendices).

Conner, W. H. and J.W. Day, Jr. 1976. Productivity and composition of a baldcypress-water

tupelo site and a bottomland hardwood site in a Louisiana swamp. American Journal of

Botany 63:1354-1364.

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.

Hatton, R.S., R.D. DeLaune, and W.H. Patrick, Jr. 1983. Sedimentation, accretion and

subsidence in marshes of Barataria Basin, Louisiana. Limnol. Oceanogr. 28/3:494-502.

Hoeppner, S. 2008. Swamp Ecology in a Dynamic Coastal Landscape: An Investigation

through Field Study and Simulation Modeling. Ph.D. Dissertation. Louisiana State

University, Baton Rouge, LA.

Keddy, P.A., D. Campbell, T. McFalls, G.P. Shaffer, R. Moreau, C. Dranguet, and R. Heleniak.

2007. The Wetlands and Lakes Pontchartrain and Maurepas: Past, Present and Future.

Environmental Review 15:43-77.

Laiche, G.S. 1980. The fishes of the Amite River Drainage in Mississippi and Louisiana. M.S.

Thesis. University of New Orleans, New Orleans, LA.

Lantz, K.E. 1970. An ecological survey of factors affecting fish production in a Louisiana

backwater area and river. Louisiana Wildlife and Fisheries Commission. Fisheries

Bulletin No. 5. 60 pp.

Louisiana Coastal Area. 2004. Louisiana Coastal Area (LCA) Ecosystem Restoration Study.

Volume II: Final Programmatic Environmental Impact Statement. New Orleans District,

New Orleans, LA. 918 pp.

Louisiana Coastal Protection and Restoration. 2008. USACE Louisiana Coastal Protection and

Restoration (LACPR): Draft Technical Report.

Louisiana Coastal Wetlands Conservation and Restoration Task Force. 2006. Coastal Wetlands

Planning, Protection, and Restoration Act - Wetland Value Assessment Methodology:

Procedural Manual. Environmental Work Group. 23 pp.

Louisiana Department of Environmental Quality. 2007. 2006 Water Quality Integrated Report.

Louisiana Department of Environmental Quality, Water Quality Assessment Division,

Water Quality Inventory Section 305(b). Baton Rouge, LA.

504
21

Messina, M.G. and W.H. Conner (eds.). 1998. Southern Forested Wetlands: Ecology and

Management. Lewis publishers, New York, NY.

Pezeshki, S.R., R.D. DeLaune, and W.H. Patrick, Jr. 1990. Flooding and saltwater intrusion:

potential effects on survival and productivity of wetland forests along the U.S. Gulf

Coast. Forest Ecology and Management 33/34:287-301.

Roberts, H.H. 1985. A study of sedimentation and subsidence in South-Central Coastal Plain of

Louisiana. Final Report to the U. S. Army Corps of Engineers, New Orleans District,

New Orleans, Louisiana. Pp. 53.

Rybczyk, J.M., J.W. Day, Jr., and W.H. Conner. 2002. The impact of wastewater effluent on

accretion and decomposition in a subsiding forested wetland. Wetlands, 22, 18-32.

Shaffer, G.P., J. Willis, S.S. Hoeppner, A.C. Parsons, and M. Hester. 2001. Characterization of

Ecosystem Health of the Maurepas Swamp, Lake Pontchartrain Basin, Louisiana:

Feasibility and Projected Benefits of a Freshwater Diversion. CWPPRA PPL 11.

Shaffer, G.P., T.E. Perkins, S.S. Hoeppner, S. Howell, H. Benard, and A.C. Parsons. 2003.

Ecosystem Health of the Maurepas Swamp: Feasibility and Projected Benefits of a

Freshwater Diversion. Final Report for the Environmental Protection Agency, Region 6.

Shaffer, G.P., P.C. Stouffer, and M.A. Pourrier. 2006. A Whole System Approach for Restoring

the Wetlands of Western Lake Pontchartrain Basin. Lake Pontchartrain Basin Research

Program. 2006 Annual Report. 164 pp.

Shaffer, G.P., T.E. Perkins, D. Thomson, S. Howell, and S.S. Hoeppner. 2006. Ecology and

Restoration Potential of the Manchac Wetlands: Simulating a Diversion in the Maurepas

Swamps. Lake Pontchartrain Basin Research Program Highlight, No. 1. Southeastern

Louisiana University, Hammond, LA.

Thomson, D.A. 2000. The influence of hydrological alterations upon wetland hydrodynamics

and plant growth on the Manchac Landbridge, Southeastern Louisiana, USA. M.S.

Thesis. Southeastern Louisiana University, Hammond, LA.

Thomson, D.A., G.P. Shaffer, and J.A. McCorquodale. 2002. A potential interaction between

sea-level rise and global warming: implications for coastal stability on the Mississippi

River Deltaic Plain. Global Planet. Change. 32: 49-59.

U.S. Army Corps of Engineers. 2004. Section 1135 Preliminary Restoration Plan, Amite River

Diversion Dredge material berm Gapping, State of Louisiana, Congressional District 6.

New Orleans District, New Orleans, LA. Pp. 12.

505
22

Watson, M.B., C.J. Killebrew, M.H. Schurtz, and J.L. Landry. 1981. A Preliminary Survey of

Blind River, Louisiana. In L.A. Krumholtz, ed. The Warmwater Fisheries Symposium, A

National Symposium on Fisheries Aspects of Warmwater Streams. American Fisheries

Society, Knoxville, TN. Pp. 303-319.

Wilson, B.C., C.A. Manlove, and C.G. Esslinger. 2002. North American Waterfowl

Management Plan, Gulf Coast Joint Venture: Mississippi River Coastal Wetlands

Initiative. North American Waterfowl Management Plan, Albuquerque, NM. 28 pp. +

appendix.

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A-1

APPENDIX A

PROJECT INFORMATION SHEET WITH ASSUMPTIONS FOR LCA-ARDC

507

Wetland Value Assessment Project Information Sheet

December 2009

Project Name: Louisiana Coastal Area Amite River Diversion Canal (LCA ARDC)

Modification project

Project Type(s): Swamp restoration, hydrologic restoration, and vegetative planting

Sponsoring Agency: U.S. Army Corps of Engineers (USACE) and Louisiana

Department of Natural Resources

Preparer of Wetland Value Assessment (WVA) information sheet: Karen Soileau

Information found in this project information sheet was obtained primarily from the Draft

Feasibility Report appendix (CPE 2005 and 2007).

Project Area: The project area is situated along the Amite River Diversion Canal

(ARDC) in Ascension and Livingston Parishes, in the vicinity of Head of Island,

Louisiana. The project area is focused around the impaired bald cypress-tupelo swamp

stands adjacent to the ARDC, extending northward and southward of the canal in the

western portion of the Maurepas Swamp, located within the Pontchartrain Basin.

Project area boundaries were developed and delineated based on hydrologic features of

the area suspected of being influenced by the LCA ARDC Modification project. For

planning purposes, the project area was further divided into nine sub-areas. Those subareas are defined by topographic high points (e.g., dredged material berms, relict railroad

grade, road embankments) or natural and artificial channels (e.g., rivers, canals) that

would serve to impede or intercept hydrologic flows.

Problem: The project area includes the ARDC, a 10.6-mile-long flood control channel

between the Amite and Blind Rivers. Dredged material excavated during channel

construction was deposited in dredged material berms on either side of the canal. The

construction of the ARDC and its associated dredged material berms, and the resulting

impoundment, channelization, surge-related saltwater intrusion, and the loss of

freshwater, sediments, and nutrients from the Amite River have all caused significant

adverse impacts to the area, resulting in poor swamp health and ecosystem degradation in

the western Maurepas Swamp.

Goal: The goal of the LCA ARDC Modification project is to reverse the trend of

degradation in the western portion of the Maurepas Swamp, so as to contribute toward

achieving and sustaining a coastal ecosystem that can support and protect the

environment, economy, and culture of southern Louisiana and thus the Nation.

Objectives:

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2

Increase hydrologic connectivity between the degraded swamp and

bottomland hardwood habitats within the study area and the ARDC by

increasing the exchange of freshwater, sediments, and nutrients over the 50-

year period of analysis.

Reduce habitat conversion of swamp to open water within the study area over

the 50-year period of analysis.

Facilitate natural hydrologic cycle within the study area over the 50-year

period of analysis by reducing impoundment in degraded swamp and

bottomland hardwood habitats adjacent to the ARDC to improve tree

productivity and seedling germination.

Improve fish and wildlife habitat within the study area over the 50-year period

of analysis.

Project Features:

1. Freshwater Reintroduction  Restoring processes that input freshwater, nutrients,

and sediments are essential for establishing sustainable coastal swamp systems.

The implementation of freshwater reintroduction measures that establish

hydrologic connectivity between study area waterbodies and the adjacent swamp

habitat could nourish existing swamp habitat to increase productivity and restore

areas that have converted to freshwater marsh or open water, reintroduce

sediments and nutrients throughout the ecosystem, and allow aquatic organisms

access to previously unavailable habitats. The benefits that such reintroductions

produce increase over time and continue as long as the reintroduction is operated

and maintained. Additionally, freshwater reintroductions can be adaptively

managed to respond to environmental changes and optimize benefits.

2. Habitat Restoration  The majority of the Maurepas Swamp is stressed as a result

of hydrologic alteration and seems to be on a trajectory of slow degradation

leading to a gradual conversion to marsh and open water (Hoeppner et al., 2007).

Without restoration, the factors and processes that are contributing to stress and

deterioration of the swamps in the vicinity of the ARDC would continue and

would result in loss of the swamp, with succession to open water. The wetland

loss rates for the Coast 2050 Amite/Blind Rivers mapping unit (which contains

the study area) for 1974-90 were estimated by the Corps to be 0.83 percent per

year for swamp habitat, and 0.02 percent per year for fresh marsh. Based on these

rates, approximately 50 percent of swamp and 1.2 percent of fresh marsh would

be lost within 60 years (Coastal Wetlands Planning, Protection, and Restoration

Act [CWPPRA] Task Force, 2002). Additionally, the Corps determined that,

based on the low tree density, degraded condition, and expectation for mortality,

the majority of swamp habitat within the study area would degrade to less than 33

percent canopy cover within 20 years (USACE, 2004). Under the continued

influence of these conditions, tree mortality would continue to increase and tree

density would continue to decline, until most swamp habitat in the vicinity of the

ARDC converts to fresh marsh. Monitoring studies conducted for the CWPPRA

Priority Project List 12 (PPL 12) proposal indicated that conversion of bald

cypress-tupelo swamp to fresh marsh is already occurring in the study area,

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3

particularly north of the ARDC in subunit NE-2 (CWPPRA Task Force, 2002).

Additionally, the monitoring results indicate that many areas of fresh marsh in the

greater southern Maurepas Swamp have converted to fragile spikerush flotant,

which is particularly susceptible to nutrient starvation and fragmentation.

Consequently, it is expected that the vast majority of swamp habitat adjacent to

the ARDC would convert to open water rather than stable marsh habitat without

implementation of the proposed project.

LOW SEA LEVEL RISE SCENARIO ASSUMPTIONS

Primary Impact Areas

Fresh Marsh  The Swamp Model was chosen for this area over the Fresh Marsh

Model, even though there is less than a 33 percent canopy cover, because the area

provides functions and values more closely associated with a swamp than a fresh

marsh.

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. It was the consensus of the

group that there is less than 33 percent overstory

closure. [Class 1]

Future Without Project

Target Years 1  50 

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, the

area is expected to remain a Class 1.

Future With Project

Target Year 1 

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 1.

Future With Project

Target Year 10 

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4

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. However, cypress trees planted at TY1

would be 11 years old. In Louisiana, the height of

cypress at 10 years of age is, on average, 17 feet

(U.S. Department of Agriculture [USDA] 1980).

Therefore, because there were no tree species within

the midstory at TY 0 and because planted cypress

trees would not be old enough yet to be considered

a component of the overstory, we anticipate the

stand structure would remain a Class 1.

Future With Project

Target Year 25 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

and would, therefore, be considered a component of

the overstory. Accordingly, we anticipate an

overstory closure of 50 -75 percent with a midstory

or herbaceous cover greater than 33 percent. [Class

4]

Future With Project

Target Year 50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should continue to improve habitat

conditions within the area. Accordingly, we

anticipate an overstory closure of greater than or

equal to 75 percent with either a midstory cover or

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

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5

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His diameter at

breast height (dbh) estimate, for all tree species

combined, was between 6.5 and 8.25 inches, as

compared to our average of 6.3 inches determined

during our Wetland Value Assessment (WVA) data

collection field assessment. Although our estimate

is on the lower end of the range determined by Mr.

Wood, because the subject area represents some of

the more degraded habitat we feel that this estimate

is representative of existing habitat conditions.

Basal area was estimated based on information

gathered during the aforementioned field visit and

data collected by Southeast Louisiana University

over the past 10 years.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated utilizing data collected by Southeast

Louisiana University and percent composition of

canopy trees was estimated based on best

professional judgment. Within the PPL 12 WVA it

was assumed that 50 percent of the tupelo et al

would die over 20 years, but that actual mortality of

cypress would be minimal. Over the 50 year project

life, we assume that 75 percent of the tupelo et al

would die with minimal cypress mortality. In

addition, we assume that minimal regeneration

would occur over 50 years based on the degraded

habitat conditions and lack of tree species at TY 0

in the understory. Subsequently, under the future

513
6

without project scenario, basal areas decreased from

time year 0 to 50.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the primary impact areas would receive

the most benefits from freshwater flows, nutrients,

and sediments; thus, those areas should see the

greatest increase in growth. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 167% of current growth in the

primary impact areas, which is the same assumption

used in the PPL 12 WVA. Percent composition of

cypress trees in the canopy was increased over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 

At present the Maurepas Swamp within this portion

of the project area are permanently flooded and

have no flow/exchange.

Future Without Project

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7

Target Years 1  50 

Continued degradation of the area is expected under

the future without project scenario and we

anticipate the project area to remain permanently

flooded with no flow/exchange.

Future With Project

Target Years 1  50 

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

Subsidence is expected to continue within the

project area over time under the future without

project scenario. We, therefore, assume that the

ability for saltwater to intrude further and/or more

frequently into the project area swamps would

likewise increase. Because the subject area is

impounded with no flow/exchange we expect the

515
8

salinity to increase over time. Thus, we assumed

that mean high salinity during the growing season to

increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 ppt from TY 1-10).

Because of the anticipated increase in sea level rise

over time, however, we assume an increase in mean

high salinities of 1.0 and 1.2 ppt for TY 25 and 50,

respectively.

10 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

35 percent with an approximate midstory cover of

17 percent. [Class 2]

Future Without Project

Target Year 1 

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 2.

Future Without Project

Target Years 10  50 

516
9

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, we

downgraded the variable to a Class 1.

Future With Project

Target Year 1 

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 2.

Future With Project

Target Year 10 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. While the majority cypress trees in the

project area (planted at TY1) would be 11 years old,

and would not be old enough yet to be considered a

component of the overstory, other midstory tree

species present at TY 0 (i.e., red maple, green ash,

and water tupelo) would become a component of

the overstory at TY 10. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. Thus, we anticipate an

overstory canopy closure between 33 and 50

percent and greater than a 33 percent midstory or

herbaceous cover. [Class 3]

Future With Project

Target Years 25  50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

517
10

and would, therefore, be considered a component of

the overstory. Because construction of the gaps is

designed to allow for drainage of the area during

ARDC low flow events, seedling germination,

establishment, and survival is expected to increase.

Thus, we anticipate an overstory canopy closure

equal to or greater than 75 percent with a

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

7.2 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

518
11

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality. In addition, we assume that minimal

regeneration would occur over 50 years based on

the degraded habitat conditions. Subsequently,

under the future without project scenario, basal

areas decreased from time year 0 to 50.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the high benefit areas would receive the

most benefits from freshwater flows, nutrients, and

sediments; thus, those areas should see the greatest

increase in growth. These assumptions are similar

to those by Hamilton and Shaffer (2001) for the

Maurepas Diversion Project. Results of studies by

John Day in wetlands receiving secondary treated

sewage suggest that introduction of nutrients as well

as sediments from river water could stimulate

production by 3-5 fold (Hamilton and Shaffer

2001). Comparison of productivity in swamps that

are either managed, have more favorable hydrology,

and/or are receiving nutrient enrichment suggest

that the existing level of productivity in Maurepas

are 1⁄2 to 1⁄4 of average values. As a conservative

projection, we assume growth rates to be 167% of

current growth in the primary impact areas, which is

the same assumption used in the PPL 12 WVA.

Percent composition of cypress trees was adjusted

over the 50 years to mimic conditions in healthier

portions of the project area. Basal area was

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 

At present the Maurepas Swamp within the project

519
12

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1  50 

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1  50 

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

520
13

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season to increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 ppt from TY 1-10).

Because of the anticipated increase in sea level rise

over time, however, we assume an increase in mean

high salinities of 1.0 and 1.2 ppt for TY 25 and 50,

respectively.

20 - 30 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

60 percent with an approximate midstory cover of

approximately 35 percent. [Class 4]

Future Without Project

Target Year 1 

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

521
14

Class 4.

Future Without Project

Target Years 10  50 

Continued degradation of the area is anticipated

under the future without project scenario. Because

of this, we assumed that overstory closure would be

reduced to less than 50 percent by TY10 (Class 2)

and less than 33 percent by TY25 (Class 1).

Future With Project

Target Year 1 

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

Future With Project

Target Year 10 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25  50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

522
15

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

7.9 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was

estimated based on data collected by Southeast

Louisiana University over the past 10 years and

percent composition of canopy trees was estimated

based on best professional judgment. Within the

PPL 12 WVA it was assumed that 50 percent of the

tupelo et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality occurring within the 10 year to marsh

habitat type. Because habitat quality and conditions

523
16

are higher in the 20 year to marsh habitat type, as

compared to the 10 year to marsh habitat type, we

assume that tupelo mortality would occur, but at a

slower rate. Therefore, we predict that 50 percent

of the tupelo et al would die over the 50 year project

life. Subsequently, under the future without project

scenario, basal areas decreased from time year 0 to

50.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the primary impact areas would receive

the most benefits from freshwater flows, nutrients,

and sediments; thus, those areas should see the

greatest increase in growth. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 167% of current growth in the

high benefit areas, which is the same assumption

used in the PPL 12 WVA. Percent composition of

cypress trees was adjusted over the 50 years to

mimic conditions in healthier portions of the project

area. Basal area was estimated by a bottomland

hardwood growth/basal area calculator developed

by the United States Forest Service (Putnam et al.

1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 

524
17

At present the Maurepas Swamp within the project

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1  50 

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1  50 

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

525
18

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season to increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 parts per thousand

[ppt] from TY 1-10). Because of the anticipated

increase in sea level rise over time, however, we

assume an increase in mean high salinities of 1.0

and 1.2 ppt for TY 25 and 50, respectively.

30 -50 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

This information was provided by Bernard Wood

(Research Assistant Southeastern Louisiana

University). Specifically, total canopy cover is

estimated to be between 50 and 75 percent with a

midstory cover greater than 33 percent or a

herbaceous cover greater than 33 percent. [Class 4]

Future Without Project

Target Year 1 

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

526
19

Class 4.

Future Without Project

Target Years 10  50 

Continued degradation of the area is anticipated

under the future without project scenario. Because

of this, we assumed that overstory closure would be

reduced to less than 50 percent by TY25 (Class 3)

and less than 33 percent by TY50 (Class 1).

Future With Project

Target Year 1 

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

Future With Project

Target Year 10 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25  50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

527
20

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 

This information was provided by Bernard Wood

through direct measurement of project area trees.

Future Without Project

Target Years 1  50 

Values based on information provided by Bernard

Wood. Mean dbh for each species was estimated as

the mean existing dbh plus the existing mean annual

growth rate times X number of years (growth rate:

cypress = .15 inches per year tupelo et al = .10

inches per year). Basal area was estimated based on

data collected by Southeast Louisiana University

over the past 10 years and percent composition of

canopy trees was estimated based on best

professional judgment. Within the PPL 12 WVA it

was assumed that 50 percent of the tupelo et al

would die over 20 years, but that actual mortality of

cypress would be minimal. Over the 50 year project

life, we assume that 75 percent of the tupelo et al

would die with minimal cypress mortality occurring

within the 10 year to marsh habitat type. Because

habitat quality and conditions are higher in the 30 -

50 year to marsh habitat type, as compared to the 10

year to marsh habitat type, we assume that tupelo

mortality would occur, but at a slower rate.

Therefore, we predict that 50 percent of the tupelo

et al would die over the 50 year project life.

Subsequently, under the future without project

scenario basal areas decrease slightly from time

year 0 to 25 and decrease significantly between time

year 25 and 50 due to the projected loss of canopy

cover.

Future With Project

528
21

Target Years 1  50 

Values based on information presented in the PPL

12 WVA and information provided by Mr. Bernard

Wood. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the primary impact areas would receive

the most benefits from freshwater flows, nutrients,

and sediments; thus, those areas should see the

greatest increase in growth. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 167% of current growth in the

high benefit areas, which is the same assumption

used in the PPL 12 WVA. Percent composition of

cypress trees was adjusted over the 50 years to

mimic conditions in healthier portions of the project

area. Basal area was estimated by a bottomland

hardwood growth/basal area calculator developed

by the United States Forest Service (Putnam et al.

1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 

At present the Maurepas Swamp within the project

area are temporarily flooded and have low

flow/exchange.

Future Without Project

Target Years 1  50 

Continued degradation of the area is expected under

529
22

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain temporarily flooded

over 50 years.

Future With Project

Target Years 1  50 

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season to increase to 1.4 ppt over 50 years.

530
23

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 ppt from TY 1-10).

Because of the anticipated increase in sea level rise

over time, however, we assume an increase in mean

high salinities of 1.0 and 1.2 ppt for TY 25 and 50,

respectively.

Secondary Impact Areas

Fresh Marsh  The Swamp Model was chosen for this area over the Fresh Marsh

Model, even though there is less than a 33 percent canopy cover, because the area

provides functions and values more closely associated with a swamp than a fresh

marsh.

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. It was the consensus of the

group that there is less than 33 percent overstory

closure. [Class 1]

Future Without Project

Target Years 1  50 

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, the

area is expected to remain a Class 1.

Future With Project

Target Year 1 

531
24

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 1.

Future With Project

Target Year 10 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. However, cypress trees planted at TY1

would be 11 years old. In Louisiana, the height of

cypress at 10 years of age is, on average, 17 feet

(USDA 1980). Therefore, because there were no

tree species within the midstory at TY 0 and

because planted cypress trees would not be old

enough yet to be considered a component of the

overstory, we anticipate the stand structure would

remain a Class 1.

Future With Project

Target Year 25 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

and would, therefore, be considered a component of

the overstory. Accordingly, we anticipate an

overstory closure of 50 -75 percent with a midstory

or herbaceous cover greater than 33 percent. [Class

4]

Future With Project

Target Year 50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

532
25

planting should continue to improve habitat

conditions within the area. Accordingly, we

anticipate an overstory closure of greater than or

equal to 75 percent with either a midstory cover or

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

6.3 inches determined during our WVA data

collection field assessment. Although our estimate

is on the lower end of the range determined by Mr.

Wood, because the subject area represents some of

the more degraded habitat we feel that this estimate

is representative of existing habitat conditions.

Basal area was estimated based on information

gathered during the aforementioned field visit and

data collected by Southeast Louisiana University

over the past 10 years.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

533
26

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality. In addition, we assume that minimal

regeneration would occur over 50 years based on

the degraded habitat conditions and lack of tree

species at TY 0 in the understory. Subsequently,

under the future without project scenario, basal

areas decreased from time year 0 to 50.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

receive the benefits from freshwater flows,

nutrients, and sediments; however, to a lesser extent

than the primary impact areas. These assumptions

are similar to those by Hamilton and Shaffer (2001)

for the Maurepas Diversion Project. Results of

studies by John Day in wetlands receiving

secondary treated sewage suggest that introduction

of nutrients as well as sediments from river water

could stimulate production by 3-5 fold (Hamilton

and Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960) and is assumed to result in

similar conditions as the 155 acre fresh marsh high

benefit area since vegetated plantings are proposed.

Variable 3: Water Regime

534
27

Both Future With and Future Without Project

Target Year 0 

At present the Maurepas Swamp within this portion

of the project area are semi-permanently flooded

and have low flow/exchange.

Future Without Project

Target Years 1  50 

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1  50 

We assume that the portions of the proposed project

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

anticipate a semi-permanent flood duration with

moderate flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the ARDC project is further from the lake

(i.e., further from the source of saltwater intrusion)

535
28

the CWPPRA Environmental Work Group assumed

a lower mean high salinity in this area and adopted

1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

10 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

536
29

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

35 percent with an approximate midstory cover of

17 percent. [Class 2]

Future Without Project

Target Year 1 

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 2.

Future Without Project

Target Years 10  50 

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, we

downgraded the variable to a Class 1.

Future With Project

Target Year 1 

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 2.

Future With Project

Target Year 10 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. While the majority cypress trees in the

project area (planted at TY1) would be 11 years old,

and would not be old enough yet to be considered a

component of the overstory, other midstory tree

species present at TY 0 (i.e., red maple, green ash,

and water tupelo) would become a component of

the overstory at TY 10. In addition, because

537
30

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. Thus, we anticipate an

overstory canopy closure between 33 and 50

percent and greater than a 33 percent midstory or

herbaceous cover. [Class 3]

Future With Project

Target Years 25  50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

and would, therefore, be considered a component of

the overstory. Because construction of the gaps is

designed to allow for drainage of the area during

ARDC low flow events, seedling germination,

establishment, and survival is expected to increase.

Thus, we anticipate an overstory canopy closure

equal to or greater than 75 percent with a

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

7.2 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

538
31

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality. In addition, we assume that minimal

regeneration would occur over 50 years based on

the degraded habitat conditions. Subsequently,

under the future without project scenario, basal

areas decreased from time year 0 to 50.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

receive the benefits from freshwater flows,

nutrients, and sediments; however, to a lesser extent

than the primary impact areas. These assumptions

are similar to those by Hamilton and Shaffer (2001)

for the Maurepas Diversion Project. Results of

studies by John Day in wetlands receiving

secondary treated sewage suggest that introduction

of nutrients as well as sediments from river water

could stimulate production by 3-5 fold (Hamilton

and Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

539
32

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 

At present the Maurepas Swamp within the project

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1  50 

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1  50 

We assume that the portions of the proposed project

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

540
33

anticipate a semi-permanent flood duration with

moderate flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

541
34

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

20 - 30 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

60 percent with an approximate midstory cover of

approximately 35 percent. [Class 4]

Future Without Project

Target Year 1 

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 4.

Future Without Project

Target Years 10  50 

Continued degradation of the area is anticipated

under the future without project scenario. Because

of this, we assumed that overstory closure would be

reduced to less than 50 percent by TY10 (Class 2)

and less than 33 percent by TY25 (Class 1).

Future With Project

Target Year 1 

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

542
35

Future With Project

Target Year 10 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25  50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

543
36

6.5 and 8.25 inches, as compared to our average of

7.9 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality occurring within the 10 year to marsh

habitat type. Because habitat quality and conditions

are higher in the 20 year to marsh habitat type, as

compared to the 10 year to marsh habitat type, we

assume that tupelo mortality would occur, but at a

slower rate. Therefore, we predict that 50 percent

of the tupelo et al would die over the 50 year project

life. Subsequently, under the future without project

scenario, basal areas decrease from time year 0 to

50.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

544
37

receive benefits from freshwater flows, nutrients,

and sediments; however, to a lesser extent than the

primary impact areas. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 

At present the Maurepas Swamp within the project

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1  50 

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1  50 

545
38

We assume that the portions of the proposed project

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

anticipate a semi-permanent flood duration with

moderate flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1  50 

546
39

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

30 -50 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 

This information was provided by Bernard Wood

(Research Assistant Southeastern Louisiana

University). Specifically, total canopy cover is

estimated to be between 50 and 75 percent with a

midstory cover greater than 33 percent or a

herbaceous cover greater than 33 percent. [Class 4]

Future Without Project

Target Year 1 

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 4.

Future Without Project

Target Years 10  50 

Degradation of the area is anticipated under the

future without project scenario. Because of this, we

assumed that overstory closure would be reduced to

547
40

less than 50 percent by TY25 (Class 3) and less than

33 percent by TY50 (Class 1).

Future With Project

Target Year 1 

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

Future With Project

Target Year 10 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25  50 

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

548
41

Both Future With and Future Without Project

Target Year 0 

This information was provided by Bernard Wood

through direct measurement of project area trees.

Future Without Project

Target Years 1  50 

Values based on information provided by Bernard

Wood. Mean dbh for each species was estimated as

the mean existing dbh plus the existing mean annual

growth rate times X number of years (growth rate:

cypress = .15 inches per year tupelo et al = .10

inches per year). Basal area was estimated based on

data collected by Southeast Louisiana University

over the past 10 years and percent composition of

canopy trees was estimated based on best

professional judgment. Within the PPL 12 WVA it

was assumed that 50 percent of the tupelo et al

would die over 20 years, but that actual mortality of

cypress would be minimal. Over the 50 year project

life, we assume that 75 percent of the tupelo et al

would die with minimal cypress mortality occurring

within the 10 year to marsh habitat type. Because

habitat quality and conditions are higher in the 30 -

50 year to marsh habitat type, as compared to the 10

year to marsh habitat type, we assume that tupelo

mortality would occur, but at a slower rate.

Therefore, we predict that 50 percent of the tupelo

et al would die over the 50 year project life.

Subsequently, under the future without project

scenario basal areas decrease slightly from time

year 0 to 25 and decrease significantly between time

year 25 and 50 due to the projected loss of canopy

cover.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

receive benefits from freshwater flows, nutrients,

549
42

and sediments; however, to a lesser extent than the

primary impact areas. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 

At present the Maurepas Swamp within the project

area are temporarily flooded and have low

flow/exchange.

Future Without Project

Target Years 1  50 

Degradation of the area is expected under the future

without project scenario. Because the area has

some level of flow/exchange (albeit low), we

anticipate the area to remain temporarily flooded

over 50 years.

Future With Project

Target Years 1  50 

We assume that the portions of the proposed project

550
43

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

anticipate a temporary flood duration with moderate

flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1  50 

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1  50 

Values based on information presented in the PPL

551
44

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

552
B-1

APPENDIX B

WVA SUMMARY SHEET FOR LCA-ARDC

553



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APPENDIX C

NOAA FISHERIES SERVICE

COORDINATION LETTER

641

643

645
646
647

Comments from the letter dated July 1, 2010,

are addressed in Appendix G.

649

651
652
653
654
655

Appendix D

404(b)(1) WATER QUALITY

REPORT

657

1

SECTION 404(b)(1) EVALUATION

AMITE RIVER DIVERSION CANAL MODIFICATION PROJECT,

LIVINGSTON AND ASCENSION PARISHES, LOUISIANA

I. INTRODUCTION

A. Purpose and General Description.

The placement of material dredged to construct the Amite River Diversion Canal (ARDC)

adjacent to the canal created a hydrologic barrier that has isolated the swamps north and south of

the ARDC. This has created standing water conditions that have led to degradation of the

swamp habitats and prevented the introduction of nutrients that would promote the healthy

growth and regeneration of plants.

The purpose of this project is to construct cuts in the dredged material banks on the north side of

the ARDC to promote the exchange of water between the ARDC and the adjacent swamps. This

action would allow periodic drying of the swamps, thereby enabling regeneration of trees. The

action would enable the introduction of nutrients from the ARDC into the swamps, thereby

promoting healthy growth of plants.

Features of the proposed action (Figure 1) include:

• Three dredged material bank openings and three bifurcated conveyance channels in

the north bank of the ARDC in NE-2 with the westernmost channel in the north bank

of the ARDC also extending through the railroad grade into NE-1 to add connectivity

between NE-1, NE-2, and the ARDC.

• Dredged material (5.0 acres) from the bank openings and the conveyance channel

would be sidecast on both sides of the proposed channel. Gaps will be left in the

disposal berms so sheet flow is not reduced.

• One cut would be created in the railroad grade approximately 0.9 miles north of the

ARDC to improve sheet flow.

• Vegetative plantings of bottomland hardwood/freshwater swamp tree species on

5.0 acres of dredged material berms.

• Vegetative plantings of freshwater swamp tree species within 438 acres of the swamp

floor.

Three natural low areas or relict channels have been identified as potential bank opening and

conveyance channel sites. Openings would enable impounded water to be drained from the

swamp and provide hydrologic connectivity between the swamp and the ARDC. Additionally,

the placement of a cut in the railroad grade would provide further hydrologic connectivity

between NE-1 and NE-2. Openings would promote the introduction of freshwater, sediments,

and nutrients into the swamp and allow the oxidation of sediments and removal of toxic

metabolites. This alternative is anticipated to improve the degraded swamp and decrease the

transition to marsh and ultimately, open water. This alternative represents the minimum effort

659
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 33

Map ID: 27850108-1868

LITTLE BAYOU CHENE BLANC

NE-2

SE-2

NE-3

SE-1

NE-1

Railroad

Grade 956 Acres

Secondary

Impact Area

438 Acres

Proposed

Vegetative

Planting

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

BAYOU

BAYOU CHENE BLANC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

BLANC

CHENE

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

SE-1

Material Berm

Notes:Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 1

660
3

that would meet the goals and objectives of the project. Alternative 33 would benefit

approximately 1,602 acres of existing freshwater swamp, recreate 144 acres of freshwater swamp

from freshwater marsh, and create 5.0 acres of upland habitat from dredged material placement.

Three natural low areas or relict channels have been identified as potential bank opening and

conveyance channel sites. Openings would enable impounded water to be drained from the

swamp and provide hydrologic connectivity between the swamp and the ARDC. Additionally,

the placement of a cut in the railroad grade would provide further hydrologic connectivity

between NE-1 and NE-2. Openings would promote the introduction of freshwater, sediments,

and nutrients into the swamp and allow the oxidation of sediments and removal of toxic

metabolites. This alternative is anticipated to improve the degraded swamp and decrease the

transition to marsh and ultimately, open water. This alternative represents the minimum effort

that would meet the goals and objectives of the project. Alternative 33 would benefit

approximately 1,602 acres of existing freshwater swamp, recreate 144 acres of freshwater swamp

from freshwater marsh, and create 5.0 acres of upland habitat from dredged material placement.

B. Location.

The Louisiana Coastal Area-Amite River Diversion Canal (LCA-ARDC) study area is located in

LCA Subprovince 1 and is situated along the ARDC in Ascension and Livingston parishes, in the

vicinity of Head of Island, Louisiana. A map of the study area is presented in Figure 2. The

study area is bounded to the north by the old channel of the Amite River, Old River, and Bayou

Chene Blanc; to the east by the Blind River; to the south by the Petite Amite River and the New

River Canal; and to the west by the Saveiro Canal, Ascension Parish flood protection levees, and

the Laurel Ridge Canal; and is located in the following sections:

• Township 9 South, Range 4 East- Sections 9-16, 22-27, and 34-36;

• Township 9 South, Range 5 East- Sections 7, 14-36;

• Township 9 South, Range 6 East- Section 30;

• Township 10 South, Range 4 East- Sections 1-3 and 10-12; and

• Township 10 South, Range 5 East- Sections 2-11.

C. Authority.

Title VII of Water Resource Development Act (WRDA) 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,

restoration project construction, a program for beneficial use of dredged material, feasibility

studies for restoration plan components, and other program elements.

In total, the LCA program has authority for 25 elements falling into various components

including investigations, research, demonstrations, and construction. This report outlines the

study elements requiring Congressional reporting that will be undertaken in partnership between

the U.S. Army Corps of Engineers (USACE) and the State of Louisiana. Specifically, Section

7006(e)(3) requires the Secretary of the Army to submit feasibility reports to Congress on six

661
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:Source: USDA/GEC

STUDY AREA REGION

Map ID: 27850108-1781

Lake

Maurepas

Lake

Pontchartrain

22

Mississippi River

Iberville

Parish

Amite River Diversion Canal

Blind River

Amite River

Amite River

Livingston Parish

Ascension Parish

St. John the Baptist Parish

Tangipahoa

Parish

St. James Parish

East Baton

Rouge Parish

10

12

61

51

22

444

70

16

42

74

447

621

30

63

928 931 44

431

1037

933

941

426

429

932

929

641

934

935

1026

1033

3115

1039

427

1038

937

930

936

43

938

441

1032

42

22

42

22

73

429

42

18

942

61

405

55

Killian

Garyville Reserve

Baton Rouge

Gonzales

Sorrento

St.

Gabriel

French

Settlement

Port

Vincent

Springfield

Lutcher

1:260,000

0246 1

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study AreaCities and TownsParishesWater Bodies

Figure: 2

662
5

elements by December 31, 2008 and one Chief’s Report by December 31, 2010. The six

elements are:

1) Multipurpose Operation of Houma Navigation Lock,

2) Terrebonne Basin Barrier Shoreline Restoration,

3) Small Diversion at Convent/Blind River,

4) Amite River Diversion Canal Modification,

5) Medium Diversion at White Ditch, and

6) Convey Atchafalaya River Water to Northern Terrebonne Marshes.

D. General Description of Dredged and Fill Material.

(1) General Characteristics of Material.

(a) Construction of Gaps in ARDC Dredged Material Banks (Figure 3). The material to be

dredged for creating gaps in the ARDC dredged material bank is former swamp floor sediment

that was previously dredged to construct the ARDC and placed adjacent to the channel. This

material is primarily alluvial silt and clay that was deposited by annual flooding of the

Mississippi and Amite Rivers along with varying amounts of organic matter.

Excavation of the gaps within the existing dredged material berms would be carried out by two

amphibious, short-reach excavators a D-6 dozer, and a log skidder. As the equipment cuts its

way into the gap locations, the dredged material removed would be placed on the swamp floor at

the interface of the existing dredged material berm and the conveyance channels to create

bottomland hardwood (BLH) “islands” that would serve as wildlife refugia during time of high

water. A total of 5.0 acres of dredged material would be placed within the construction footprint

for the proposed action. It is anticipated that it would be necessary to remove stumps that are

encountered during the dredging of the gaps. Best management practices, such as silt fencing

and hay bales would be utilized during the construction process to prevent the transport of

sediments within the construction and placement areas.

All excavation through the dredged material berms, as well as the conveyance channels through

the swamp, would be based on a design cross section (Figure 3). This cross section was

developed in an effort to mimic natural, existing cuts within the study area, which have been

determined to be self-maintaining.

(b) Construction of Cuts in Railroad Grade (See Figure 1). Material dredged to create cuts in

the railroad grade is former swamp floor material that was used to construct the railroad grade.

This material is primarily alluvial silt and clay that was deposited by annual flooding of the

Mississippi and Amite Rivers along with varying amounts of organic matter.

Excavation of the cuts within the railroad grade would be carried out by an amphibious shortreach, excavator. As the equipment cuts its way into the cut locations, the dredged material

removed would be placed on the swamp floor adjacent to the railroad grade. Material excavated

from the gaps in the railroad grade (approximately 0.02 acres) represents a small percentage of

the total acres of dredged material and is accounted for in the total 5.0 acres of dredged material

663
25 ft 25 ft 20 ft

Existing TreesTo Remain

Trees To Be Planted

Existing TreesTo Be Removed

-5 ft Elev

1.3 ft Elev

Average WaterLevel (Elev 0.7 ft +/-)

Existing Grade (Elev 18.7 ft +/-)

70 ft +/-

25 ft +/- 25 ft +/- Varies 50 ft +/-

Existing TreesTo Remain

Varies 50 ft +/-

Trees To Be Planted

3h to 1v Slope

4h to 1v Slope

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to Scale

Source: GEC

Typical 70 ft. Cross Section through ARDC Dredged Material Berm

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Area

Figure: 3

664
7

that would be placed within the construction footprint for the proposed action. It is anticipated

that it would be necessary to remove stumps that are encountered during the dredging of the cuts.

Best management practices, such as silt fencing and hay bales, would be utilized during the

construction process to prevent the transport of sediments within the construction and placement

areas.

(c) Construction of Conveyance Channels (Figure 4). Material dredged to create conveyance

channels is sediment that would be removed from the floor of the swamp. This material is

primarily alluvial silt and clay that was deposited by annual flooding of the Mississippi and

Amite Rivers along with varying amounts of organic matter.

Excavation of the conveyance channels would be carried out by two short-reach, amphibious

excavators. As the equipment cuts its way into the conveyance channel locations, the dredged

material would be placed on the swamp floor along the sides of the proposed conveyance

channels. The material will be placed in lengths of 300 feet with 50-foot gaps between the

placement areas. Material excavated during the construction of the conveyance channels would

be used to create BLH “islands” that would serve as wildlife refugia during time of high water.

This 50-foot gaps in the spoil placement will be added to prevent the placement of this material

from interrupting sheet flow throughout the areas of impact (See Figure 5). A total of 5.0 acres

of dredged material would be placed within the construction footprint for the proposed action. It

is anticipated that it would be necessary to remove stumps that are encountered during the

dredging of the gaps. Best management practices, such as silt fencing and hay bales, would be

utilized during the construction process to prevent the transport of sediments within the

construction and placement areas.

All excavation of the conveyance channels through the swamp will be based on three design

cross sections (Figures 4 through 6). These cross sections were developed in an effort to mimic

natural, existing cuts within the study area, which have been determined to be self-maintaining.

(d) Vegetative Plantings. Swamp vegetation, primarily bald cypress seedlings with

accompanying nutria protection, would be planted on the swamp floor. Bottomland hardwood

vegetation would be planted on BLH “islands” (See Figure 1.)

(2) Quantity of Material.

(a) Construction of Gaps in ARDC Dredged Material Banks. Approximately 13,753

cubic yards of material would be removed from the ARDC dredged material banks to construct

cuts.

(b) Construction of Cuts in Railroad Grade. Approximately 60 cubic yards of material

would be removed to construct cuts in the railroad grade.

(c) Construction of Conveyance Channels (Figure 7). Approximately 81,694 cubic yards

of material would be removed from the swamp floor to construct conveyance channels.

665
10 ft 5 ft 9 ft

Average WaterLevel (Elev 0.7 ft)

-2.0 ft Elev

Existing TreesTo Remain

Trees To BePlanted

Existing TreesTo Be Removed

Existing Grade ( Elev 1.0 ft +/-)

30 ft +/-

10 ft +/-

4h to 1v Slope

10 ft +/- 10 ft 10 ft 5 ft 9 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to ScaleSource: GEC

Typical 30 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Figure: 4

666
10 ft 12 ft 5 ft

Existing TreesTo Remain

Trees To BePlanted

-3.0 Elev

Existing TreesTo Be Removed

Average WaterLevel (Elev 0.7 ft +/-)

20 ft 15 ft +/- 15 ft +/-

Existing Grade ( Elev 1.0 ft +/-)

50 ft +/-

4h to 1v Slope

10 ft 12 ft 5 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to ScaleSource: GEC

Typical 50 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Figure: 5

667
Existing Grade (Elev 1.0 ft +/-)

10 ft 17 ft 5 ft

Existing TreesTo Remain

Trees To BePlanted

Existing TreesTo Be Removed

-5.0 Elev

Average WaterLevel (Elev 0.7 ft +/-)

20 Ft

70 ft +/-

25 ft +/- 25 ft +/-

4h to 1v Slope

10 ft 17 ft 5 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to Scale

Source: GEC

Typical 70 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Dimensions

Figure: 6

668
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana Source: USDA/GEC

Scale:

Date: January 2010

TYPICAL CONVEYANCE CHANNEL

Map ID: 27850108-1889

Amite River Diversion Canal

70' Channel Through Existing

Dredge Material Berm and Swamp:

20' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -5.0' +/-

50' Channel Through Swamp:

20' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -3.0' +/-

30' Channel Through Swamp:

10' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -2.0' +/-

1:5,600

0 200 400 600

Feet

Map Extent

NE-1 NE-2

SE-2

SE-1 SW-2

NW-2

Amite River

NE-3

Diversion Canal

Legend

30' Channel

50' Channel

70' Channel

Cut Through Existing Dredge Material Berm

Dredge Material & Stump Placement

Subunits

Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Figure: 7

SE-1

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12

(d) Vegetative Plantings. Approximately 438 acres of swamp floor would be planted with

swamp vegetation. BLH “islands” used as wildlife refugia, which would total approximately 5.0

acres, would be planted with bottomland hardwood forest species.

(3) Source of Material.

All material excavated and placed within the project area is present or former swamp floor native

material deposited by historic and prehistoric annual flooding of the Mississippi and Amite

Rivers. No material would be brought into the project area from outside sources.

Seedlings and 1 and 3-gallon potted plants for vegetative plantings would be purchased from

commercial nurseries.

E. Description of the Proposed Discharge Sites.

(1) Location and Size.

(a) Construction of Gaps in ARDC Dredged Material Banks. Material excavated for the

construction of gaps in the ARDC banks would be placed on the swamp flood at the interface of

the existing dredged material berm and the conveyance channels to create BLH “islands” that

would serve as wildlife refugia (see Figure 3).

(b) Construction of Cuts in Railroad Grade. Material excavated for the construction of

cuts in the railroad grade would be placed on the swamp floor adjacent to the gaps in the railroad

grade (see Figure 1).

(c) Construction of Conveyance Channels. Material excavated for the construction of

conveyance channels would be placed at alternating locations adjacent to the channels to create

BLH “islands” that would serve as wildlife refugia (see Figures 4 through 6).

(d) Vegetative Plantings. Vegetative plantings would be made on the swamp floor and

on BLH “islands” that would serve as wildlife refugia (see Figure 1).

(2) Type of Site.

(a) Construction of Gaps in ARDC Dredged Material Banks. Material excavated for the

construction of gaps in the ARDC banks would be placed within adjacent swamps to create BLH

“islands” that would serve as wildlife refugia.

(b) Construction of Cuts in Railroad Grade. Material excavated for the construction of

cuts in the railroad grade would be placed within adjacent swamps.

(c) Construction of Conveyance Channels. Material excavated for the construction of

conveyance channels would be placed along the proposed channel to create BLH “islands” that

would serve as wildlife refugia.

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13

(d) Vegetative Plantings. Seedlings and potted plants would be planted on the existing

swamp floor and on the material placed within the swamps to create BLH “islands” that would

serve as wildlife refugia.

(3) Type of Habitat.

(a) Construction of Gaps in ARDC Dredged Material Banks. Material excavated for the

construction of gaps in the banks on the northern side of the ARDC would be placed within

adjacent degraded swamps. Placement sites would include severely degraded areas that are

impounded for a majority of the year by the ARDC dredged material banks.

(b) Construction of Cuts in Railroad Grade. Material excavated for the construction of

cuts in the railroad grade on the northern side of the ARDC would be placed within adjacent

degraded swamps. Placement sites may include severely degraded areas that are impounded for

a majority of the year by the ARDC dredged material banks.

(c) Construction of Conveyance Channels. All material dredged during construction of the

conveyance channels would be placed along the channels to also create BLH habitat "islands.”

Placement sites may include severely degraded areas that are impounded for a majority of the

year by the ARDC dredged material banks.

(d) Vegetative Plantings. Plantings located on the swamp floor on the northern side of the

ARDC would be provided to promote the recovery of swamp degraded by inundation and a lack

of hydrologic connectivity. With the establishment of hydrologic connectivity through the

construction of gaps in the ARDC banks, the swamp is anticipated to regain sufficient health to

allow vegetative plantings to survive and reestablish a forest canopy.

(4) Timing and Duration of Discharge.

It is estimated that total construction time, which would involve the excavation of gaps in

the ARDC banks, excavation of gaps in the railroad grade, dredging of conveyance channels,

placement of excavated and dredged materials to create BLH “islands” used for wildlife refugia,

and plantings to revegetate the areas would take approximately six years.

F. Description of Disposal Method.

(a) Construction of Gaps in ARDC Dredged Material Banks. Excavation of the gaps

within the existing dredged material berms would be carried out by a two short-reach,

amphibious excavators.

(b) Construction of Cuts in Railroad Grade. Excavation of the gaps within the railroad

grade would be carried out by a short-reach, amphibious excavator.

(c) Construction of Conveyance Channels. Excavation of conveyance channels would be

carried out by a short-reach, amphibious excavator.

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II. FACTUAL DETERMINATIONS

A. Physical Substrate Determinations.

(1) Comparison of Existing Substrate and Fill.

(a) Construction of Gaps in ARDC Dredged Material Banks. Material that would be

excavated from the ARDC dredged material banks is former swamp substrate that was dredged

to create the ARDC, which was completed in 1963. The proposed action would place this

material back into the swamp. It is likely that the some of the physical characteristics of the

excavated material differ to some degree from the swamp substrate on which it would be placed;

the dredged material has likely consolidated and lost some of its original organic matter through

oxidation. The inorganic components of the dredged material would be identical to the existing

swamp substrate.

(b) Construction of Cuts in Railroad Grade. The railroad grade was constructed from

adjacent swamp substrate. Material excavated to construct cuts in the railroad grade would be

returned to the swamp substrate. The low elevation of the grade, which is less than one foot

above the average water level of the swamp, has likely retained most of its original

characteristics and is expected to be virtually identical to the existing swamp substrate.

(c) Construction of Conveyance Channels. Material excavated to construct conveyance

channels is existing swamp substrate that would be placed on like material.

(2) Changes to Disposal Area Elevation.

(a) Construction of Gaps in ARDC Dredged Material Banks. Figure 3 shows a cross

section of the construction for a typical gap in the ARDC bank; elevations are indicated. The

removal of material from the ARDC bank would reduce the elevation to a minimum of

approximately 5.5 feet below the average water level in the canal. Material removed to create

the gaps would be placed on the swamp floor to create BLH “islands” that would provide refugia

for wildlife during periods of high water in the swamp. The elevations of the BHL “islands”

would be approximately 10 feet, before consolidation, and would change the habitat type from

swamp to bottomland hardwood and upland forest.

(b) Construction of Cuts in Railroad Grade. The elevation of the railroad grade at the

location of the cut would be reduced to a minimum of 1 foot below the average water level in the

swamp. The material removed to construct the cut would be placed on the swamp floor, raising

the elevation at the placement location to approximately two to four feet, which may change the

habitat type at some locations to bottomland hardwood forest.

(c) Construction of Conveyance Channels. The construction of conveyance channels

would reduce the elevation of the substrate to approximately 5.5 feet below the average water

level of the swamp (Figures 4 through 6). Material removed to construct conveyance channels

would be placed on the swamp floor, raising the elevation at those locations to approximately

four feet, which would change the habitat type to bottomland hardwood forest.

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15

(3) Migration of Fill.

Because of the low velocities of water flow across the swamp and the revegetation of

areas where fill would be placed, it is anticipated that little or no migration of fill would occur.

(4) Duration and Extent of Substrate Change.

Material excavated for the construction of gaps in the ARDC banks, material excavated

for the construction of cuts in the railroad grade, and material dredged for the construction of

conveyance channels would be placed on the swamp floor in proximity to the construction area.

Material removed would be placed on the swamp floor to create BLH “islands” that would

provide refugia for wildlife during periods of high water in the swamp as recommended by

representatives of the Louisiana Department of Wildlife and Fisheries. Figures 1, and 3 through

7, show the approximate locations of placement sites. It is intended that these sites would be

permanent.

(5) Changes to Environmental Quality and Value.

Physical substrates would be altered by the excavation of material for the construction of

gaps in the ARDC dredged material berms and the cuts in the railroad grade, as well as the

dredging of conveyance channels. At these locations, existing elevations would be lowered.

Material removed by excavation and dredging would be placed at locations on the swamp floor

where the elevation would be raised to create BLH “islands” that would provide refugia for

wildlife during periods of high water in the swamp. Although these actions would alter existing

habitats, the overall effect of the proposed action would enhance the environmental quality of the

study area.

(6) Actions to Minimize Impacts. It is anticipated that construction activities would

involve the use short-reach, amphibious excavators, the use of which would result in fewer

impacts to the physical substrate that alternative methods. Some clearing of vegetation would be

necessary to provide access to the sites for construction activities, but revegetation of disturbed

areas is included in the proposed action. Best management practices, such as silt fencing and hay

bales, would be utilized during the construction process to prevent the transport of sediments

within the construction and placement areas.

B. Water Circulation, Fluctuation, and Salinity Determinations.

(1) Alteration of Current Patterns and Water Circulation.

The proposed action is intended to reverse the effects of alterations in flow that were

caused by the construction of the ARDC and deposition of dredged material along the banks

thereby impeding the hydrologic connectivity needed for the maintenance of a healthy swamp.

The construction of gaps in the banks and cuts in the railroad grade are intended to (1) remove

the impoundments on the northern side of the ARDC and provide hydrologic connectivity

between the swamp and the ARDC; (2) promote the introduction of flows from the ARDC to

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16

swamps adjacent to the ARDC during periods of elevated water levels in the ARDC; (3) provide

a degree of sheet flow by removing restrictions created by the railroad grade.

(2) Interference with Water Level Fluctuation.

The proposed action is intended to eliminate the impoundments created by the ARDC

dredged material banks and provide the swamp with seasonal water level fluctuations necessary

to maintain a healthy swamp.

(3) Salinity Gradient Alteration.

Salt water is currently being introduced into the swamp during storm tides, such as those

experienced during tropical cyclone storm surges. Because of the lack of hydrologic

connectivity, this salt water remains resident in the swamps for extended periods of time, which

results in extensive mortality to swamp vegetation. The gaps in the ARDC banks and cuts in the

railroad grade would provide a means for the salt water to be flushed from the swamp and reduce

mortality through the resulting increase in hydrologic connectivity that would occur.

(4) Effects on Water Quality.

(a) Salinity. No effect.

(b) Clarity. Effects of the proposed action on water clarity would be most likely to occur

during construction. Excavation associated with the construction of gaps, cuts and access

channels would reduce water clarity, as would the placement of material excavated during

construction. However, any reduction in clarity caused by construction activities would be short

duration and clarity would return to pre-construction levels following the revegetation of banks

and placement areas.

(c) Color. With the establishment of hydrologic connectivity between water from

impounded areas within the swamp on would be able to drain from into the ARDC. Because of

dissolved tannins and lignins originating from the decomposition of organic matter, swamp water

may have a darker color than the water in the ARDC This color difference would be most

noticeable in the immediate vicinity of the gaps in the ARDC bank. The colored water would

not have any adverse effect on water quality. As mixing occurs in the ARDC, any noticeable

color would be lost.

A similar occurrence of the introduction of colored swamp water may be seen during high flow

conditions when water is introduced from the ARDC to swamps through gaps in the bank of the

ARDC. Water flowing from swamps may be of a darker color than ambient water in Blind

River.

(d) Water Chemistry and Dissolved Gasses. Materials excavated and dredged 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

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the swamps and the ARDC would reduce dissolved oxygen deficits and facilitate the

transformation of ammonia into non-toxic nitrate. The introduction of swamp water into the

ARDC may create low dissolved oxygen concentration near gaps in the banks, particularly

during summer, but it is anticipated that any adverse effects would be localized.

(e) Temperature. No effect.

(f) Nutrients. An existing problem with the swamps along the ARDC is a lack of

nutrients. One of the objectives of the proposed action is to allow waters in the ARDC to supply

nutrients to the adjacent swamps. This would provide a slight decrease in the concentrations of

nutrients in the ARDC.

(5) Changes to Environmental Quality and Value.

Construction activities may temporarily affect water quality by increasing

turbidity/suspended solids in the swamps and the ARDC, but turbidity/suspended solid

concentrations would return to preconstruction activities following completion of the project.

(6) Actions Taken to Minimize Impacts.

The primary adverse impacts on water circulation, fluctuation, and water quality are

likely to be increased concentrations of turbidity/suspended solids in the swamps and the ARDC.

Best management practices, such as silt fencing and hay bales would minimize impacts.

Turbidity/suspended solid concentrations would return to preconstruction activities following

completion of the project

C. Suspended Particulate/Turbidity Determinations.

(1) Alteration of Suspended Particulate Type and Concentration.

Material excavated from the ARDC banks and railroad grade and material dredged to

construct conveyance channels is of similar physical and chemical quality to existing substrates

within the swamps. Particulates suspended during project construction or by natural forces after

project completion are not expected to differ in type from particulates currently within the

project area. Construction operations are expected to temporarily increase the concentration of

suspended particulates. Particulates suspended during project construction would dissipate after

construction activities are complete.

(2) Particulate Plumes Associated with Discharge.

Temporary and localized particulate plumes may occur in the ARDC during construction

activities but would quickly dissipate after construction is complete. The placement of excavated

and dredged material within the swamp to create BLH “islands” that would provide wildlife

refugia is expected to result in temporary occurrences of elevated turbidity. Turbidity levels

would return to pre-construction levels following construction and revegetation of the sites.

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(3) Changes to Environmental Quality and Value.

Particulate plumes resulting from any construction activity are not expected to persist

after project completion. Particulates suspended by the deposition of excavated and dredged

material at the placement during project construction or by natural forces after project

completion are not expected to differ in type from particulates currently within the study area.

(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, which may

form turbidity plumes in the ARDC and the swamp, may occur. This would be minimized by

implementation of best management practices, such as silt fencing and hay bales, to prevent the

transport of sediments within the construction and placement areas.

D. Contaminant Determinations.

Fill material is former swamp sediment that would be returned to the swamp floor. There are no

indications that the material has contaminants. The nearest development is primarily residential,

but the areas to be excavated are not in the immediate vicinity of development. A phase I

environmental site assessment of the study revealed no potential sources of contamination at or

near the construction areas.

E. Aquatic Ecosystem and Organisms Determinations.

(1) Effects on Plankton.

Because of the presence of a forest canopy and floating vegetation (primarily salvinia and

water hyacinth), a plankton community within the swamps is unlikely to be a significant

resource. Therefore the placement of material excavated to construct gaps in the ARDC banks,

railroad cuts, or conveyance channels would have little, if any, effect on plankton.

However, it is likely that a plankton community is present in the ARDC. The excavation of the

banks to construct gaps is likely to create sufficient turbidity in the vicinity of construction to

adversely affect plankton during project construction. Other project activities, such as loading

and unloading equipment, construction of staging areas, etc., may temporarily increase turbidity

within the ARDC and may adversely impact plankton during operations.

(2) Effects on Benthos.

Benthic organisms would be smothered by the discharge of dredged material at material

placement sites, where increased elevations would eliminate benthic habitats. Benthic organisms

from adjacent areas would colonize substrates within conveyance channels and open water areas

within constructed gaps and cuts. With the establishment of hydrologic connectivity between the

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swamps and the ARDC, benthic populations in areas that are permanently impounded would be

replaced by population characteristic of seasonally flooded swamps.

(3) Effects on Nekton.

Some species of the nekton community in the ARDC may be temporarily displaced

during construction operations. Construction of gaps, cuts, and conveyance channels would

provide an array of foraging, breeding, spawning, and cover habitat for a variety of adult and

juvenile fishes. Reestablishment of hydrologic connectivity would enable the utilization of

numerous microenvironments by juvenile fishes.

(4) Effects on the Aquatic Food Web.

The aquatic food web would benefit from both short and long-term changes resulting

from the proposed action, including additions in energy to basal elements of the food web,

habitat preservation, and increased habitat complexity. Nutrients and detritus provided by the

enhancement of degraded swamp habitats would be added to the existing food web. The

proposed action would reestablish numerous microenvironments that would be utilized by

invertebrates and juvenile fishes that serve as prey items for larger fauna.

(5) Effects on Threatened and Endangered Species.

The West Indian manatee, listed as endangered in Ascension Parish, is the only species

likely to occur in the study area. The West Indian manatee is generally found in shallow, slowmoving rivers, estuaries, saltwater bays, canals and coastal areas. According to an inventory of

manatee sightings compiled by the Louisiana Sea Grant Program, manatees have been sighted in

the Amite River north of Bayou Manchac, upstream from Port Vincent and near the ARDC; the

Blind River; and in Lakes Maurepas and Pontchartrain. Precautionary measures would be

necessary to avoid harming these animals during construction activities.

(6) Effects on Other Wildlife.

Representatives of the Louisiana Department of Wildlife and Fisheries have

recommended that project features include the placement of excavated material on the swamp

floor to create BLH “islands” that would serve as refugia for such wildlife as white-tailed deer

during periods of high water levels within the swamp. These refugia have been incorporated into

the proposed action. Therefore, the proposed action is expected to benefit terrestrial wildlife of

the study area.

The bald eagle, although delisted, remains protected under the Bald and Golden Eagle Protection

Act and the Migratory Bird Treaty Act. The bald eagle occurs in quiet coastal areas and along

rivers or lakes near large tall trees. Eagles and eagle nests have been sighted in the western

Maurepas Swamp, and at least one bald eagle nest is known to occur within the study area in the

vicinity of NE-2. The conveyance channels were located to avoid potential impacts to the nest

tree in accordance with the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty

Act.

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(7) Actions to Minimize Impacts.

Adverse impacts on benthic organisms are unavoidable. However, the loss of benthic

habitat by the placement of excavated/dredged material on the swamp floor would be

compensated by the improvement in water quality in the swamp. Additional benthic habitat

would be provided by the construction of conveyance channels.

The plankton community of the ARDC may be affected by increased concentrations of

turbidity/suspended solids during construction. Best management practices, such as silt fencing

and hay bales, would minimize impacts. Turbidity/suspended solid concentrations would return

to preconstruction activities following completion of the project.

Avoidance of activities in an area within 660 feet of the bald eagle nest, particularly

during the nesting season, is expected to minimize disturbances.

F. Proposed Disposal Site Determinations.

Representatives of the State of Louisiana, Department of Wildlife and Fisheries have requested

that material removed for the construction of gaps in the ARDC dredged material berms, cuts in

the railroad grade, and conveyance channels be used to create BLH “islands” that could serve as

resting areas and refugia for wildlife during periods when the swamp is flooded. These

placement sites would be in proximity to the areas from which the material is removed, and the

excavated/dredged material would be similar in nature to the substrate onto which it would be

placed.

The placement areas would convert 5.0 acres of swamp habitat to bottomland hardwood forest

habitat and upland habitat. However, the benefits of providing refugia for wildlife would

outweigh the loss of wetlands, especially when the overall benefits of the proposed action would

enhance the quality of 1,602 acres of forested wetlands.

G. Determination of Cumulative Effects on the Aquatic Ecosystem.

The proposed project would improve the quality of 1,602 acres of forested wetlands. Within

these 1,633 acres, 438 acres of swamp vegetation would be replanted to restore the quality of

degraded swamps. Wetland Value Assessments determined that 679 Average Annual Habitat

Units (AAHUs) would be gained by the proposed action.

The proposed project would restore productive swamp habitat, while restoring hydrologic

connectivity between the swamps and adjoining water bodies. Therefore, the incremental effect

of the proposed action, when combined with past, present, and reasonably foreseeable future

projects, would be of a beneficial nature, thereby lessening the overall cumulative impacts of

projects and actions within the study area.

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H. Determination of Secondary Effects on the Aquatic Ecosystem.

No secondary effects, other than the effects discussed in previous sections (some of which may

be considered secondary), are expected.

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 in 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. No effect on water supplies is

expected.

(b) Recreational and Commercial Fisheries. No adverse effects on recreational and

commercial fisheries are expected.

(c) Plankton. Plankton are expected to decrease in the immediate area of project

construction operations due to increased turbidity. Adverse effects may linger for a period of

time afterwards but would diminish as water clarity returns to preconstruction levels.

(d) Fish. No adverse effects on fish populations are expected.

(e) Wildlife. The proposed action would create BLH “islands” that would serve as

refugia during periods of high water in the swamp. The effect of the proposed action would be

beneficial.

(f) Special Aquatic Sites. No special aquatic sites would be adversely impacted.

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(2) Effects on Life Stages of Aquatic Life and Other Wildlife Dependent on Aquatic

Ecosystems.

The proposed action is expected to enhance and preserve degraded swamp habitats that

provide an array of foraging, breeding, spawning, and cover habitat for a variety of adult and

juvenile fishes, birds, mammals, and reptiles. The proposed action would restore numerous

microenvironments that would be utilized as cover for juvenile fishes and invertebrates.

(3) Effects on Aquatic Ecosystem Diversity, Productivity and Stability.

The proposed action would enhance areas of degraded swamp, thereby enhancing and

preserving diversity, productivity, and stability of the study area.

(4) Effects on Recreational, Aesthetic, and Economic Resources.

The proposed action would enhance areas of degraded swamp, thereby preserving areas

that contribute to recreational, aesthetic, and economic benefits.

G. Appropriate and Practicable Steps Taken to Minimize Potential Adverse Impacts of the

Discharge on the Aquatic Ecosystem.

Construction equipment that would be used in swamps would be amphibious, short-reach

excavators, which would create a lower impact on the swamp substrate than other methods such

as board roads and conventional construction equipment. Standard best management practices

would be implemented to minimize the erosion of exposed soil and the introduction of suspended

solids into swamps and the ARDC. Revegetation of disturbed areas and material placement

areas is a component of the proposed action. Any impacts on the aquatic ecosystem are

expected to be minor and of short term. The intent of the project is to restore and maintain a

high quality aquatic ecosystem.

IV. EVALUATION RESPONSIBILITY

Evaluation Prepared By:

Renée L. Sanders, Coastal Resources Scientist III,

Office of Coastal Protection and Restoration Authority, Plan Development Section,

P.O. Box 44027, Capital Station, Baton Rouge, LA 70804-4027

Jonathan E. Puls, P.E., GEC, Project Manager Environmental Sciences & Engineering, 9357

Interline Avenue, Baton Rouge, LA 70809

Evaluation Reviewed By:

William P. Klein, Jr., Ed.D. U.S. Army Corps of Engineers, New Orleans District, P.O. Box

60267, New Orleans, LA 70118

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-7-

Planning, Programs, and

Project Management Division

Environmental Planning

and Compliance Branch

PUBLIC NOTICE

LOUISIANA COASTAL AREA - ECOSYSTEM RESTORATION PROJECT

AMITE RIVER DIVERSION CANAL MODIFICATION PROJECT,

LIVINGSTON AND ASCENSION PARISHES, LOUISIANA

Introduction. This Public Notice is issued in accordance with provisions of Title 33 CFR

Parts 336.1(b)(1) and 337.1, which establish policy, practices, and procedures to be followed on

federal actions involving the disposal of dredged or fill material into waters of the United States.

Project Authority. The authority for the proposed action is Title VII of the Water Resources

Development Act (WRDA) 2007 authorizes the Louisiana Coastal Area (LCA) ecosystem

restoration program.

Location. The proposed action is located in Livingston and Ascension Parishs, Louisiana.

The study area is bounded to the north by the old channel of the Amite River, Old River, and

Bayou Chene Blanc; to the east by the Blind River; to the south by the Petite Amite River and

the New River Canal; and to the west by the Saveiro Canal, Ascension Parish flood protection

levees, and the Laurel Ridge Canal.

Project Description. The USACE proposes to dredge openings in the existing Amite River

Diversion Canal (ARDC) spoil banks, construct bifurcated conveyance channels, and establish

vegetative plantings in the study area. Without action, approximately 18,204 acres of impounded

swamp habitat would continue converting from a freshwater swamp to fragmented freshwater

marsh and open water habitats. Dredged material (5.0 acres) from the bank openings and the

conveyance channel would be sidecast on both sides of the proposed channel. Gaps will be left in

the disposal berms so sheet flow is not reduced. The proposed action itself consists of measures

to minimize the adverse effects of storm water erosion and thus requires no separate measures or

controls for compliance with CWA Section 402(p) and LAC 33:IX.2341.B.14.j.

Discharges by Others.

Other Information. A Draft Environmental Impact Statement (DEIS), entitled Integrated

Louisiana Coastal Area - Ecosystem Restoration Project Feasibility Study and Supplemental

Environmental Impact Statement for Amite River Diversion Canal Modification Project,

Livingston and Ascension Parishes, Louisiana, was mailed to the public for a 45-day review on

May 21, 2010. The DEIS addressed the impacts associated with the construction of a proposed

dredge openings in the existing Amite River Diversion Canal (ARDC) spoil banks, construct

bifurcated conveyance channels.

Properties Adjacent to Disposal Sites. The proposed action is adjacent to Amite River

Diversion Canal.

683
-8-

Status of EIS and Other Environmental Documents. Environmental compliance for the

proposed action would be achieved upon: coordination of the EIS and supporting documents

with appropriate agencies, organizations, and individuals for their review and comments; U.S.

Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS)

confirmation that the proposed action would not be likely to adversely affect any endangered or

threatened species; Louisiana Department of Natural Resources concurrence with the

determination that the proposed action is consistent, to the maximum extent practicable, with the

Louisiana Coastal Resources Program; receipt of a Water Quality Certificate from the State of

Louisiana; public review of the Section 404(b)(1) Public Notice; signature of the Section

404(b)(1) Evaluation; receipt of the Louisiana State Historic Preservation Officer Determination

of No Affect on cultural resources; receipt and acceptance or resolution of all USFWS Fish and

Wildlife Coordination Act recommendations; receipt and acceptance or resolution of all

Louisiana Department of Environmental Quality comments on the air quality impact analysis

documented in the EA; and receipt and acceptance or resolution of all NMFS Essential Fish

Habitat recommendations. The draft ROD would not be signed until the proposed action

achieves environmental compliance with applicable laws and regulations, as described above.

Coordination. The following is a partial list of agencies to which a copy of this notice is

being sent:

U.S. Environmental Protection Agency, Region VI

U.S. Fish and Wildlife Service

National Marine Fisheries Service

U.S. Coast Guard, Eighth District

Louisiana Department of Environmental Quality

Louisiana Department of Natural Resources

Louisiana Department of Wildlife and Fisheries

Louisiana Department of Transportation and Development

Louisiana State Historic Preservation Officer

This notice is being distributed to these and other appropriate Congressional, federal, state,

and local interests, environmental organizations, and other interested parties.

Evaluation Factors. Evaluation includes application of the Section 404(b)(1) guidelines

promulgated by the Administrator of the U.S. Environmental Protection Agency, through

40 CFR 230.

Public Involvement. Interested parties may express their views on the disposal of material

associated with the proposed action or suggest modifications. All comments postmarked on or

before the expiration of the comment period for this notice will be considered.

Any person who has an interest that may be affected by deposition of excavated or dredged

material may request a public hearing. The request must be submitted in writing to the District

Engineer within the comment period of this notice and must clearly set forth the interest that may

be affected and the manner in which the interest may be affected by the proposed action.

684
-9-

You are requested to communicate the information contained in this notice to any parties

who may have an interest in the proposed action.

For further information regarding the proposed action, please contact Dr. Klein at

(504) 862-2540. Dr. Klein's FAX number is (504) 862-2572 and his E-mail address is William

.P.Klein@usace.army.mil.

Joan M. Exnicios

Chief, Environmental Planning

and Compliance Branch

COMMENT PERIOD FOR THIS PUBLIC NOTICE EXPIRES: June 21, 2010

685

APPLICATION FOR DEPARTMENT OF THE ARMY PERMIT

(33 CFR 325)

OMB APPROVAL NO. 0710-003

Expires October 1996

Public reporting burden for this collection of information is estimated to average 5 hours per response, including the time for reviewing

instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of

information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions

for reducing this burden, to Department of Defense, Washington Headquarters Service Directorate of Information Operations and Reports,

1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302; and to the Office of Management and Budget, Paperwork Reduction

Project (0710-0003), Washington, DC 20503. Please DO NOT RETURN your form to either of those addresses. Completed applications

must be submitted to the District Engineer having jurisdiction over the location of the proposed activity.

PRIVACY ACT STATEMENT

Authority: 33 USC 401, Section 10; 1413, Section 404. Principal Purpose: These laws require permits authorizing activities in, or affecting,

navigable waters of the United States, the discharge of dredged or fill material into waters of the United States, and the transportation of dredged

material for the purpose of dumping it into ocean waters. Routine Uses: Information provided on this form will be used in evaluating the application

for a permit. Disclosure: Disclosure of requested information is voluntary. If information is not provided, however, the permit application cannot be

processed nor can a permit be issued.

One set of original drawings or good reproducible copies which show the location and character of the proposed activity must be attached to this

application (see sample drawings and instructions) and be submitted to the District Engineer having jurisdiction over the location of the proposed

activity. An application that is not completed in full will be returned.

(ITEMS 1 THRU 4 TO BE FILLED BY THE CORPS)

1. APPLICATION NO. 2. FIELD OFFICE CODE 3. DATE RECEIVED 4. DATE APPLICATION COMPLETED

(ITEMS BELOW TO BE FILLED BY APPLICANT)

5. APPLICANT'S NAME

U.S. Army Corps of Engineers, New Orleans District

8. AUTHORIZED AGENT'S NAME AND TITLE (an agent is not required)

Not Applicable

6. APPLICANT'S ADDRESS

CEMVN

P.O. Box 60267

New Orleans, LA 70160-0267

9. AGENT'S ADDRESS

Not Applicable

7. APPLICANT'S PHONE NOS. W/AREA CODE 10. AGENT'S PHONE NOS. W/AREA CODE

a. Residence :

b. Business : (225) 862-1958

a. Residence : Not Applicable

b. Business : Not Applicable

11. STATEMENT OF AUTHORIZATION

APPLICANT'S SIGNATURE DATE __________________

NAME, LOCATION AND DESCRIPTION OF PROJECT OR ACTIVITY

12. PROJECT NAME OR TITLE (see instructions)

Louisiana Coastal Area-Amite River Diversion Canal Modification Project

13. NAME OF WATER BODY, IF KNOWN (if applicable)

Amite River Diversion Canal

14. PROJECT STREET ADDRESS (if applicable)

Not Applicable

15. LOCATION OF PROJECT

Livingston and Ascension LA

PARISH STATE

16. OTHER LOCATION DESCRIPTIONS, IF KNOWN (see instructions)

17. DIRECTIONS TO THE SITE

The project site extends along the Amite River Diversion Canal between the Petite Amite River and Blind River.

687
18. Nature of Activity (Description of project, include all features)

Features of the proposed action (Figure 1) include:

• Three dredged material bank openings and three bifurcated conveyance channels in the north bank of the ARDC in

NE-2 with the westernmost channel in the north bank of the ARDC also extending through the railroad grade into NE1 to add connectivity between NE-1, NE-2, and the ARDC.

• Dredged material (5.0 acres) from the bank openings and the conveyance channel would be sidecast on both sides of

the proposed channel. Gaps will be left in the disposal berms so sheet flow is not reduced.

• One cut would be created in the railroad grade approximately 0.9 miles north of the ARDC to improve sheet flow.

• Vegetative plantings of bottomland hardwood/freshwater swamp tree species on 5.0 acres of dredged material berms.

• Vegetative plantings of freshwater swamp tree species within 438 acres of the swamp floor.

Three natural low areas or relict channels have been identified as potential bank opening and conveyance channel

sites. Openings would enable impounded water to be drained from the swamp and provide hydrologic connectivity

between the swamp and the ARDC. Additionally, the placement of a cut in the railroad grade would provide further

hydrologic connectivity between NE-1 and NE-2. Openings would promote the introduction of freshwater, sediments,

and nutrients into the swamp and allow the oxidation of sediments and removal of toxic metabolites. This alternative is

anticipated to improve the degraded swamp and decrease the transition to marsh and ultimately, open water. This

alternative represents the minimum effort that would meet the goals and objectives of the project. Alternative 33 would

benefit approximately 1,602 acres of existing freshwater swamp, recreate 144 acres of freshwater swamp from

freshwater marsh, and create 5.0 acres of upland habitat from dredged material placement.

19. Project Purpose (Describe the reason or purpose of the project, see Instructions)

The purpose of this project is to construct cuts in the dredged material banks on the north side of the Amite River

Diversion Canal to promote the exchange of water between the Diversion Canal and the swamps. This action would

allow periodic drying of the swamps, thereby enabling regeneration of trees. The action would enable the introduction of

nutrients from the Amite River Diversion Canal into the swamps, thereby promoting healthy growth of plants. Excavated

and dredged material will be used to create elevated areas that would provide refuges for wildlife during periods of high

water in the swamp.

USE BLOCKS 20-22 IF DREDGED AND/OR FILL MATERIAL IS TO BE DISCHARGED

20. Reason(s) for Discharge

The placement of material dredged to construct the Amite River Diversion Canal along the banks created a hydrologic

barrier that has isolated the swamps north and south of the Amite River Diversion Canal. This has created standing

water conditions that have led to degradation of the swamp habitats and prevented the introduction of nutrients that

would promote the healthy growth and regeneration of plants. The degraded swamps are in the process of transitioning

to freshwater marshes and open water. Without the proposed action, this transition will continue.

21. Type(s) of Material Being Discharged and the Amount of Each Type in Cubic Yards

The material to be excavated and dredged is former swamp floor sediment. This material is primarily alluvial silt and

clay that was deposited by annual flooding of the Mississippi and Amite Rivers along with varying amounts of organic

matter. It is anticipated that it would be necessary to remove stumps that are encountered during the dredging of the

gaps. The amount of material is estimated to be 95,447cubic yards.

Approximately 438 acres would be planted with vegetation. Swamp vegetation, primary baldcypress seedlings with

accompanying nutria protection would be planted on the swamp floor. Bottomland hardwood vegetation would be

planted on material placement sites.

22. Surface Area in Acres of Wetlands or Other Waters Filled (see instructions)

Elevated placement areas would total approximately 5.0 acres and would be planted with bottomland hardwood forest

species.

23. Is Any Portion of the Work Already Complete? Yes No X IF YES, DESCRIBE THE COMPLETED WORK

688
689

Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 33

Map ID: 27850108-1868

LITTLE BAYOU CHENE BLANC

NE-2

SE-2

NE-3

SE-1

NE-1

Railroad

Grade 956 Acres

Secondary

Impact Area

438 Acres

Proposed

Vegetative

Planting

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

BAYOU

BAYOU CHENE BLANC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

BLANC

CHENE

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

SE-1

Material Berm

Notes:Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 1

691

May 21, 2010

Melvin C. Mitchell, Sr.

Louisiana Dept. of Env. Quality

Water Quality Certifications Section

P.O. Box 4313

Planning, Programs, and

Project Management Division

Environmental Planning

and Compliance Branch

Dear Mr. Mitchell, Sr.:

The 2004 Louisiana Coastal Area (LCA) Report identified critical projects, multiple

programmatic authorizations, and ten additional required feasibility studies for the LCA.

When the Water Resources Development Act of 2007 was passed, it included authorization

under Title VII, for the LCA Program and specific authorization for feasibility reports on six

of the ten near-term elements.

Two elements were determined to be hydrologically intertwined and the planning efforts

were combined into Convey Atchafalaya River Water to Northern Terrebonne Marshes and

Multipurpose Operation of Houma Navigation Lock EIS Lafourche, Terrebonne, St. Mary

Parish, Louisiana. The Terrebonne Basin Barrier Shoreline Restoration Study EIS (Volume V)

is being completed under a separate feasibility effort due to a need for additional alternatives

analysis and increasing uncertainties resulting from the Deepwater Horizon oil spill off the

Louisiana coast. Consequently, only four of the Draft EIS and a Summary Document

(Volume I) are available for public review at this time:

DEPARTMENT OF THE ARMY

NEW ORLEANS DISTRICT, CORPS OF ENGINEERS

P.O. BOX 60267

NEW ORLEANS, LOUISIANA 70160-0267

REPLY TO

ATTENTION OF:

An application for a State Water Quality Certificate, prepared by the U.S. Army Corps of

Engineers, New Orleans District (MVN) is enclosed. MVN staff request that a water quality

certification be completed, pursuant to Section 401 of the Clean Water Act of 1977, as

amended (33 U.S.C., Section 1341). The draft environmental impact statement (EIS) for the

LCA Amite River Diversion Canal Modification, Louisiana, project is enclosed for your

review and comment.

Baton Rouge, LA 70821-4313

693
- 2 -

Comments may also be provided by E-Mail to william.p.klein.Jr@usace. army.mil, or by

fax to (504) 862-2088. Dr. Klein may be contacted at (504) 862-2540, if questions arise.

Please review the enclosed documents and provide comments within 45 days of the date

stamped on the cover page of the EIS. Comments should be mailed to the attention of Dr.

William Klein Jr.; U.S. Army Corps of Engineers; Planning, Programs, and Project

Management Division; Environmental Planning and Compliance Branch; CEMVN-PM-RS;

P.O. Box 60267; New Orleans, Louisiana 70160-0267.

Amite River Diversion Canal Modification EIS (Volume II)

Convey Atchafalaya River Water to Northern Terrebonne Marsh /

Multipurpose Operation of the Houma Navigation Lock EIS (Volume III)

Small Diversion at Convent / Blind River EIS (Volume IV)

Medium Diversion at White Ditch EIS (Volume VI)

Enclosed with this letter are Volumes I and II. A copy of the other draft EIS are available

upon request.

The USACE proposes to dredge openings in the existing Amite River Diversion Canal

(ARDC) spoil banks, construct bifurcated conveyance channels, and establish vegetative

plantings in the study area. Without action, approximately 18,204 acres of impounded swamp

habitat would continue converting from a freshwater swamp to fragmented freshwater marsh

and open water habitats. Excluding the No-Action Alternative, the final array of alternatives

included seven options. Alternative 33 was chosen as the Tentatively Selected Plan (TSP).

The TSP, at a total estimated construction cost of $7,770,000, would restore approximately

1,602 acres of swamp habitat, create 679 Average Annual Habitat Units (AAHUs), 5.0 acres

of bottomland hardwood habitat, establish hydrologic connectivity, promote the germination

and survival of the seedlings of bald cypress and other trees, and improve biological

productivity.

To the best of our knowledge any dredge/fill material will be free of contaminants. Please

provide the public notice for publication in the Advocate of Baton Rouge to the person listed

below, as soon as possible. In addition to sending us a hard copy of the public notice

documents, we request that you send a complete electronic copy via E-Mail to

william.p.klein.Jr@usace.army.mil.

694
- 3 -

Chief, Environmental Planning

and Compliance Branch

Joan M. Exnicios for

Sincerely,

Enclosures

695

697
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698
Appendix E

LOUISIANA COASTAL

RESOURCES PROGRAM

CONSISTENCY DETERMINATION

699
This page intentionally left blank.

700
LOUISIANA COASTAL RESOURCES PROGRAM

CONSISTENCY DETERMINATION

AMITE RIVER DIVERSION CANAL MODIFICATION PROJECT,

LIVINGSTON AND ASCENSION PARISHES, LOUISIANA

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, the U.S. Army Corps of

Engineers (USACE), New Orleans District has prepared a Consistency

Determination for the Louisiana Coastal Area Amite River Diversion Canal (LCA

ARDC) Modification project. Coastal Use Guidelines were written in order to

implement the policies and goals of the Louisiana Coastal Resources Program, and

serve as a set of performance standards for evaluating projects. Compliance with

the Louisiana Coastal Resources Program, and therefore, Section 307, requires

compliance with applicable Coastal Use Guidelines.

2.0 PURPOSE AND NEED FOR THE PROPOSED ACTION

The purpose of the LCA Study is to:

Identify the most critical human and natural ecological needs of the coastal

area;

Present and evaluate conceptual alternatives for meeting the most critical

needs;

Identify the kinds of restoration features that could be implemented in the

near-term (within 5 to 10 years) that address the most critical needs, and

propose to address those needs though features that provide the highest return

in net benefits per dollar of cost;

Establish priorities among the identified near-term restoration features;

Describe a process by which the identified priority near-term restoration

features could be developed, approved, and implemented;

Identify the key scientific uncertainties and engineering challenges facing the

effort to protect and restore the ecosystem, and propose a strategy for resolving

them;

Identify, assess and, if appropriate, recommend feasibility studies that could

be undertaken within the next 5 to 10 years to fully explore other potentially

promising large-scale restoration concepts; and



701
Present a strategy for addressing the long-term needs of coastal Louisiana

restoration beyond the near-term focus of the Louisiana Coastal Area

Ecosystem Restoration Plan (LCA Plan).

Within the framework of the LCA Plan, the purpose of the proposed action is to

address the problems of altered hydrology, swamp impoundment, decreased

freshwater, sediment and nutrient input from the Amite River, decreased

productivity, subsidence, impaired water quality, increased seedling mortality, and

wetland degradation and loss within the study area. The USACE proposes to

protect and restore, to the maximum extent practicable, the bald cypress-tupelo

swamp within the study area. The LCA ARDC Modification project addresses

systematic restoration of bald cypress-tupelo swamp in areas affected by the ARDC,

and includes measures designed to prevent future bald cypress-tupelo swamp

degradation and conversion, restore sheet flow impaired by dredged material bank

construction, and protect vital socioeconomic and public resources.

The construction of the ARDC and the placement of dredged material along the

banks to form continuous berms resulted in the impoundment, channelization,

surge-related saltwater intrusion, and loss of freshwater, sediments, and nutrients

from Amite River overbank flows. These alterations have all caused significant

adverse impacts to the study area, resulting in poor swamp health and ecosystem

degradation in the western Maurepas Swamp.

Prior studies and reports have documented degradation in the swamp adjacent to

the ARDC and have demonstrated a need for ecosystem restoration that simulates

historical hydrologic conditions. Without intervention, these problems would

progressively get worse, until a significant portion of the bald cypress-tupelo swamp

habitat within the study area is converted, initially to fresh marsh, and ultimately

to shallow open water habitat.

This project is needed to establish hydrologic connectivity between the ARDC and

adjacent swamp habitat to allow floodwaters to introduce additional nutrients and

sediment into western Maurepas Swamp. The exchange of flow would occur during

flood events on the river and from the runoff of localized rainfall events. Nutrients

and sediment associated with the fresh water would be delivered to the swamp to

facilitate organic deposition in the swamp, improve biological productivity, and

prevent further habitat deterioration. Establishment of hydrologic connectivity is

needed to allow swamps to drain during seasonal low-flow events, which would

promote seedling germination and survival. Finally, establishment of hydrologic

connectivity is needed to prevent the swamp habitat from converting to fresh marsh

or open water.

As part of the goal of the LCA Plan, the goal of which is to reverse the current trend

of degradation of the coastal ecosystem, the goal of the LCA ARDC Modification



702
project is to reverse the trend of degradation within the western Maurepas Swamp

ecosystem that has been adversely affected by the construction of the ARDC. The

LCA ARDC Modification project would contribute toward 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 LCA ARDC Modification project, with respect to the study

area, include:

Increase hydrologic connectivity between the degraded swamp and

bottomland hardwood habitats within the study area and the ARDC by

increasing the exchange of freshwater, sediments, and nutrients over

the 50-year period of analysis.

Reduce habitat conversion of swamp to open water within the study

area over the 50-year period of analysis.

Facilitate natural hydrologic cycle within the study area over the 50-

year period of analysis by reducing impoundment in degraded swamp

and bottomland hardwood habitats adjacent to the ARDC to improve

tree productivity and seedling germination.

Restore fish and wildlife habitat within the study area over the 50-year

period of analysis.

This project would complement two other LCA projects: LCA Small Diversion at

Hope Canal Diversion and LCA Small Diversion at Convent/Blind River Diversion,

and two proposed Coastal Impact Assistance Program (CIAP) projects: CIAP

Hydrologic Restoration in Swamps West of Lake Maurepas and CIAP Bald

Cypress/Tupelo Coastal Forest Protection.

3.0 LOCATION AND GENERAL DESCRIPTION OF THE STUDY

AREA

The LCA ARDC study area (Figures 1 and 2) is situated along the ARDC in

Ascension and Livingston parishes, in the vicinity of Head of Island, Louisiana. The

study area is bounded to the north by the old channel of the Amite River, Old River,

Chinquapin Canal and Bayou Chene Blanc; to the east by the Blind River; to the

south by the Petite Amite River and the New River Canal; and to the west by the

Sevario Canal, Ascension Parish flood protection levees, and the Laurel Ridge

Canal; and is located in the following sections:

Township 9 South, Range 4 East, Sections 9-16, 22-27, and 34-36;

Township 9 South, Range 5 East, Sections 7, 14-36;



703


Township 9 South, Range 6 East, Section 30;

Township 10 South, Range 4 East, Sections 1-3 and 10-12; and

Township 10 South, Range 5 East, Sections 2-11.

For planning purposes the study area has been divided into nine separate

hydrologic subunits (Figure 2). Each subunit was developed based on hydrologic

differences that exist throughout the study area due to natural and manmade

hydrologic boundaries. These boundaries include natural topography such as

dredged material berms and natural ridges, as well as made-made and natural

canals.

704
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:Source: USDA/GEC

STUDY AREA REGION

Map ID: 27850108-1781

Lake

Maurepas

Lake

Pontchartrain

22

Mississippi River

Iberville

Parish

Amite River Diversion Canal

Blind River

Amite River

Amite River

Livingston Parish

Ascension Parish

St. John the Baptist Parish

Tangipahoa

Parish

St. James Parish

East Baton

Rouge Parish

10

12

61

51

22

444

70

16

42

74

447

621

30

63

928 931 44

431

1037

933

941

426

429

932

929

641

934

935

1026

1033

3115

1039

427

1038

937

930

936

43

938

441

1032

42

22

42

22

73

429

42

18

942

61

405

55

Killian

Garyville Reserve

Baton Rouge

Gonzales

Sorrento

St.

Gabriel

French

Settlement

Port

Vincent

Springfield

Lutcher

1:260,000

0246 1

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study AreaCities and TownsParishesWater Bodies

Figure: 1

705
Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:Source: USDA/GEC

STUDY AREA AND SUBUNITS

Map ID: 27850108-1780

Little Bayou Chene Blanc

Bayou C hene

B

la

n

c

NW-2

SE-1

SW-2

NE-2 NE-1

SE-2

NE-3

Blind River

Amite River Diversion Canal

New River Canal

Petite Amite River

Chinquapin Canal

NW-1

SW-1

Weir

Old RailroadEmbankment

Laurel Ridge Canal

Flat

Lake

Petite A mite R vi

re

Alligator Bayo u

Bayou An

ot

ni e

Bayou Chene Blanc

New River

O ld River

Petite Amite River

a B you

i P er er

Ba

oy

V

u

ci knair

Heath Bayou

1:80,000

0 0.5 1 1.5 2

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study Area Subunits

Figure: 2

706
4.0 DESCRIPTION OF THE PROPOSED ACTION

Alternative 33 of the LCA ARDC Integrated Feasibility Report and

Supplemental Environmental Impact Statement (SEIS) is the Tentatively

Selected Plan (TSP), which is depicted in Figure 3.

Features of Alternative 33 (TSP) include:

Three dredged material bank openings and three bifurcated conveyance

channels in the north bank of the ARDC in NE-2 with the westernmost

channel in the north bank of the ARDC also extending through the

railroad grade into NE-1 to add connectivity between NE-1, NE-2, and the

ARDC.

Dredged material (5.0 acres) from the bank openings and the conveyance

channel would be sidecast on both sides of the proposed channel. Gaps

will be left in the disposal berms so sheet flow is not reduced.

One cut would be created in the railroad grade approximately 0.9 miles

north of the ARDC to improve sheet flow.

Vegetative plantings of bottomland hardwood/freshwater swamp tree

species on 5.0 acres of dredged material berms.

Vegetative plantings of freshwater swamp tree species within 438 acres of

the swamp floor.

Three naturally low areas or relict channels have been identified as potential bank

opening and conveyance channel sites. Openings would enable impounded water to

be drained from the swamp and provide hydrologic connectivity between the swamp

and the ARDC. Additionally, the placement of a cut in the railroad grade would

provide further hydrologic connectivity between NE-1 and NE-2. Openings would

promote the introduction of freshwater, sediments, and nutrients into the swamp

and allow the oxidation of sediments and removal of toxic metabolites. This

alternative is anticipated to improve the degraded swamp and decrease the

transition to marsh and ultimately, open water. This alternative represents the

minimum effort that would meet the goals and objectives of the project. Alternative

33 would benefit approximately 1,602 acres of existing freshwater swamp, recreate

144 acres of freshwater swamp from freshwater marsh, and create 5.0 acres of

upland habitat from dredged material placement.



707
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 33

Map ID: 27850108-1868

LITTLE BAYOU CHENE BLANC

NE-2

SE-2

NE-3

SE-1

NE-1

Railroad

Grade 956 Acres

Secondary

Impact Area

438 Acres

Proposed

Vegetative

Planting

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

BAYOU

BAYOU CHENE BLANC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

BLANC

CHENE

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

SE-1

Material Berm

Notes:Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 3

708
5.0 GUIDELINES

1. GUIDELINES APPLICABLE TO ALL USES

Guideline 1.1 The guidelines must be read in their entirety. Any

proposed use may be subject to the requirements of more than one

guideline or section of guidelines and all applicable guidelines must

be complied with.

Response: Acknowledged.

Guideline 1.2 Conformance with applicable water and air quality

laws, standards and regulations, and with those other laws,

standards and regulations which have been incorporated into the

coastal resources program shall be deemed in conformance with the

program except to the extent that these guidelines would impose

additional requirements.

Response: Acknowledged.

Guideline 1.3 The guidelines include both general provisions

applicable to all uses and specific provisions applicable only to

certain types of uses. The general guidelines apply in all situations.

The specific guidelines apply only to the situations they address.

Specific and general guidelines should be interpreted to be

consistent with each other. In the event there is an inconsistency,

the specific should prevail.

Response: Acknowledged.

Guideline 1.4 These guidelines are not intended to nor shall they be

interpreted so as to result in an involuntary acquisition or taking of

property.

Response: No involuntary acquisition would be required for the

proposed action. Oyster leases that are anticipated to be impacted

would be acquired through the Louisiana Department of Natural

Resources oyster lease acquisition program.

Guideline 1.5 No use or activity shall 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. Revocations of such grants and donations shall

be avoided.



709
Response: No violations or revocations of such grants or donations are

expected.

Guideline 1.6 Information regarding the following general factors

shall be utilized by the permitting authority in evaluating whether

the proposed use is in compliance with the guidelines.

a) type, nature and location of use.

Response: Acknowledged.

b) elevation, soil and water conditions and flood and storm hazard

characteristics of site.

Response: Acknowledged.

c) techniques and materials used in construction, operations and

maintenance of use.

Response: Acknowledged.

d) existing drainage patterns and water regimes of surrounding area

including flow, circulation, quality, quantity and salinity; and

impacts on them.

Response: Acknowledged.

e) availability of feasible alternative sites or methods  for

implementing the use.

Response: Acknowledged.

f) designation of the area for certain uses as part of a local program.

Response: Acknowledged.

g) economic need for use and extent of impacts of use on economy of

locality.

Response: Acknowledged.

h) extent of resulting public and private benefits.

Response: Acknowledged.



710
i) extent of coastal water dependency of the use.

Response: Acknowledged.

j) existence of necessary infrastructure to support the use and public

costs resulting from use.

Response: Acknowledged.

k) extent of impacts on existing and traditional uses of the area and

on future uses for which the area is suited.

Response: Acknowledged.

l) proximity to, and extent of impacts on important natural features

such as beaches, barrier islands, tidal passes, wildlife and aquatic

habitats, and forest lands.

Response: Acknowledged.

m) the extent to which regional, state and national interests are

served including the national interest in resources and the siting of

facilities in the coastal zones as identified in the coastal resources

program.

Response: Acknowledged.

n) proximity to, and extent of impacts on, special areas, particular

areas, or other areas of particular concern of the state program or

local programs.

Response: Acknowledged.

o) likelihood of, and extent of impacts of, resulting secondary

impacts and cumulative impacts.

Response: Acknowledged.

p) proximity to and extent of impacts on public lands or works, or

historic, recreational or cultural resources.

Response: Acknowledged.



711
q) extent of impacts on navigation, fishing, public access, and

recreational opportunities.

Response: Acknowledged.

r) extent of compatibility with natural and cultural setting.

Response: Acknowledged.

s) extent of long term benefits or adverse impacts.

Response: Acknowledged.

Guideline 1.7 It is the policy of the coastal resources program to

avoid the following adverse impacts. To this end, all uses and

activities shall be planned, sited, designed, constructed, operated

and maintained to avoid to the maximum extent practicable

significant:

a) reductions in the natural supply of sediment and nutrients to the

coastal system by alterations of freshwater flow.

Response: The construction of the ARDC altered the natural

freshwater flow into the Maurepas Swamp. The intent of this

proposed action is to offset the alteration of flow created by the ARDC

dredged material placement areas, to provide hydrologic connectivity,

and to promote the supply of sediment and nutrients to the swamp.

b) adverse economic impacts on the locality of the use and affected

governmental bodies.

Response: The proposed action is not expected to have any adverse

economic impacts on the locality of the use or on nearby governmental

bodies. No industries, jobs, or other economic activities would be

adversely impacted by the proposed action.

c) detrimental discharges of inorganic nutrient compounds into

coastal waters.

Response: No detrimental discharges of inorganic nutrient

compounds would occur.

d) alterations in the natural concentration of oxygen in coastal

waters.



712
Response: There may be a temporary decrease in the dissolved

oxygen concentrations during actual construction operations, as well as

for a short time thereafter. Any effects are expected to be minor and

would occur only during actual dredging activities. Dissolved oxygen

levels would return to ambient levels following construction

operations.

e) destruction or adverse alterations of streams, wetland, tidal

passes, inshore waters and water bottoms, beaches, dunes, barrier

islands, and other natural biologically valuable areas or protective

coastal features.

Response: No adverse alterations of water bodies would result from

the proposed action. Instead, improved hydrologic connectivity would

result.

f) adverse disruption of existing social patterns.

Response: Any disruptions of social patterns would be associated with

construction activities, and would be of a short-term nature.

g) alterations of the natural temperature regime of coastal waters.

Response: No alterations of the natural temperature regime are

expected to.

h) detrimental changes in existing salinity regimes.

Response: The proposed action would not alter natural salinity

regimes in or around the project area. Salt water introduced by storm

tides currently becomes impounded behind the ARDC dredged

material placement areas. By reestablishing hydrologic connectivity

between the swamps and surrounding waterways, the proposed action

would promote the flushing of salt water from freshwater swamps.

i) detrimental changes in littoral and sediment transport processes.

Response: No detrimental changes in transport processed would

occur. Rather, the proposed action would improve the transport of

sediments into swamps.

j) adverse effects of cumulative impacts.



713
Response: Cumulative impacts represent the effects of this proposed

action in association with other past, present, and reasonably

foreseeable future projects. This proposed action provides beneficial

environmental effects and would not contribute to adverse effects of

cumulative impacts.

k) detrimental discharges of suspended solids into coastal waters,

including turbidity resulting from dredging.

Response: There would be a temporary increase in turbidity and

suspended solids during construction (dredging and placement) of

project features. However, any effects would be temporary and

conditions would return to ambient following completion of

construction activities.

l) reductions or blockage of water flow or natural circulation

patterns within or into an estuarine system or a wetland forest.

Response: The intent of this proposed action is to alleviate blockages

within the project area created by the construction of the ARDC and to

promote hydrologic connectivity.

m) discharges of pathogens or toxic substances into coastal waters.

Response: There are no known toxic or pathogenic substance levels

that are expected to significantly increase due to implementing the

proposed action.

n) adverse alteration or destruction of archaeological, historical, or

other cultural resources.

Response: Adverse alteration or destruction of cultural resources is

not expected to occur.

o) fostering of detrimental secondary impacts in undisturbed or

biologically highly productive wetland areas.

Response: Adverse impacts to wetlands would not result. As

demonstrated through Wetland Value Assessments, the proposed

action would improve the quality of wetlands. There would be an

overall net gain of 679 Average Annual Habitat Units (AAHUs).



714
p) 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.

Response: No unique or valuable habitats would be adversely

affected; the cypress-tupelo swamps of the area would be improved by

the proposed action. The project area does not contain critical habitat

for endangered species. The improvement in hydrologic connectivity

would enhance the area for fish and wildlife habitats, including

breeding areas. A portion of the Maurepas Swamp Wildlife

Management Area located in the project area would not be adversely

affected.

q) 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.

Response: No public parks, shoreline access points, public works, or

designated recreation areas would be adversely altered by the

proposed action. Blind River, which abuts the project area is a

designated scenic river, would not be adversely affected.

r) adverse disruptions of coastal wildlife and fishery migratory

patterns.

Response: The proposed action would not disrupt coastal wildlife or

fishery migratory patterns. Rather, the restoration of hydrologic

connectivity to the swamp may improve the ingress and egress of

aquatic organisms between the swamps and surrounding water bodies.

s) land loss, erosion and subsidence.

Response: The proposed action would not adversely affect land loss,

erosion, or subsidence. By improving the quality of swamp habitats

through improved hydrologic connectivity and the resulting

introduction of nutrients into the swamp, it is anticipated that

improved subsurface growth of root masses would elevate ground

levels.

t) increases in the potential for flood, hurricane or other storm

damage, or increases in the likelihood that damage will occur from

such hazards.

	

715
Response: The proposed action is not expected to increase the

potential for flood, hurricane, or other storm damage, or increase the

likelihood of damage from such hazards.

u) reductions in the long-term biological productivity of the coastal

ecosystem.

Response: As demonstrated through Wetland Value Assessment

determinations, the proposed action would improve the quality of the

ecosystem in the project area. There would be an overall net gain of

679 AAHUs.

Guideline 1.8 In those guidelines in which the modifier "maximum

extent practicable" is used, the proposed use is in compliance with

the guideline if the standard modified by the term is complied with.

If the modified standard is not complied with, the use will be in

compliance with the guideline if the permitting authority finds, after

a systematic consideration of all pertinent information regarding the

use, the site and the impacts of the use as set forth in guideline 1.6,

and a balancing of their relative significance, that the benefits

resulting from the proposed use would clearly outweigh the adverse

impacts resulting from non compliance with the modified standard

and there are no feasible and practical alternative locations,

methods and practices for the use that are in compliance

with the modified standard and: a) significant public benefits will

result from the use, or; b) the use would serve important regional,

state or national interests, including the national interest in

resources and the siting of facilities in the coastal zone identified in

the coastal resources program, or; the use is coastal water

dependent. The systematic consideration process shall also result in

a determination of those conditions necessary for the use to be in

compliance with the guideline. Those conditions shall assure that

the use is carried out utilizing those locations, methods and

practices which maximize conformance to the modified standard;

are technically, economically, environmentally, socially and legally

feasible and practical and minimize or offset those adverse impacts

listed in guideline 1.7 and in the guideline at issue.

Response: Acknowledged.

Guideline 1.9 Uses shall to the maximum extent practicable be

designed and carried out to permit multiple concurrent uses which

are appropriate for the location and to avoid unnecessary conflicts

with other uses of the vicinity.



716
Response: Generally, the project area would only be unavailable for

use during construction activities. The project area would again be

available for multiple uses following actual construction operations.

Natural waterways would not be closed.

Guideline 1.10 These guidelines are not intended to be, nor shall they

be, interpreted to allow expansion of governmental authority beyond

that established by La. R.S. 49:213.1 through 213.21, as amended; nor

shall these guidelines be interpreted so as to require permits for

specific uses legally commenced or established prior to the effective

date of the coastal use permit program nor to normal maintenance

or repair of such uses.

Response: Acknowledged.

2. GUIDELINES FOR LEVEES

Guideline 2.1 The leveeing of unmodified or biologically productive

wetlands shall be avoided to the maximum extent practicable.

Response: The proposed action would not involve the construction of

levees.

Guideline 2.2 Levees shall be planned and sited to avoid

segmentation of wetland areas and systems to the maximum extent

practicable.

Response: The proposed action would not involve the construction of

levees.

Guideline 2.3 Levees constructed for the purpose of developing or

otherwise changing the use of a wetland area shall be avoided to the

maximum extent practicable.

Response: The proposed action would not involve the construction of

levees.

Guideline 2.4 Hurricane and flood protection levees shall be located

at the non wetland/wetland interface or landward to the maximum

extent practicable.

Response: The proposed action would not involve the construction of

levees.



717
Guideline 2.5 Impoundment levees shall only be constructed in

wetland areas as part of approved water or marsh management

projects or to prevent release of pollutants.

Response: The proposed action would not involve the construction of

levees.

Guideline 2.6 Hurricane or flood protection levee systems shall be

designed, built and thereafter operated and maintained utilizing

best practical techniques to minimize disruptions of existing

hydrologic patterns, and the interchange of water, beneficial

nutrients and aquatic organisms between enclosed wetlands and

those outside the levee system.

Response: The proposed action would not involve the construction of

levees.

3. GUIDELINES FOR LINEAR FACILITIES

Guideline 3.1 Linear use alignments shall be planned to avoid

adverse impacts on areas of high biological productivity or

irreplaceable resource areas.

Response: Bifurcated conveyance channels would be dredged in

wetlands to enhance the hydrologic connectivity through the expansion

of the interface between the swamp and the ARDC. While this would

convert a portion of the swamp to open water, the overall effect would

be to improve the net quality of the wetland habitat in the project area.

Guideline 3.2 Linear facilities involving the use of dredging or filling

shall be avoided in wetland and estuarine areas to the maximum

extent practicable.

Response: Bifurcated conveyance channels would be dredged in

wetlands to enhance the hydrologic connectivity through the expansion

of the interface between the swamp and the ARDC. While this would

convert a portion of the swamp to open water, the overall effect would

be to improve the net quality of the wetland habitat in the project area.

Guideline 3.3 Linear facilities involving dredging shall be of the

minimum practical size and length.

Response: Acknowledged.



718
Guideline 3.4 To the maximum extent practicable, pipelines shall be

installed through the "push ditch" method and the ditch backfilled.

Response: Acknowledged.

Guideline 3.5 Existing corridors, rights of way, canals, and streams

shall be utilized to the maximum extent practicable for linear

facilities.

Response: Acknowledged.

Guideline 3.6 Linear facilities and alignments shall be, to the

maximum extent practicable, designed and constructed to permit

multiple uses consistent with the nature of the facility.

Response: While disruption to multiple uses of the project area may

occur during construction, multiple uses of the area would be restored

following construction.

Guideline 3.7 Linear facilities involving dredging shall not traverse

or adversely affect any barrier island.

Response: The proposed action does not occur on or near any barrier

islands.

Guideline 3.8 Linear facilities involving dredging shall not traverse

beaches, tidal passes, protective reefs or other natural gulf shoreline

unless no other alternative exists. If a beach, tidal pass, reef or other

natural gulf shoreline must be traversed for a non navigation canal,

they shall be restored at least to their natural condition immediately

upon completion of construction. Tidal passes shall not be

permanently widened or deepened except when necessary to

conduct the use. The best available restoration techniques which

improve the traversed area's ability to serve as a shoreline shall be

used.

Response: The proposed action would not traverse beaches, tidal

passes, protective reefs, or other natural gulf shorelines.

Guideline 3.9 Linear facilities shall be planned, designed, located

and built using the best practical techniques to minimize disruption

of natural hydrologic and sediment transport patterns, sheet flow,

and water quality, and to minimize adverse impacts on wetlands.



719
Response: Acknowledged.

Guideline 3.10 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.

Response: Acknowledged.

Guideline 3.11 All non navigation canals, channels and ditches which

connect more saline areas with fresher areas shall be plugged at all

waterway crossings and at intervals between crossings in order to

compartmentalize them. The plugs shall be properly maintained.

Response: The proposed action would not construct any channels or

canals that would adversely affect salinity patterns. Rather, the

proposed action would assist in flushing salt water introduced by

storm tides from the swamp, thereby improving the health of the

swamp.

Guideline 3.12 The multiple use of existing canals, directional

drilling and other practical techniques shall be utilized to the

maximum extent practicable to minimize the number and size of

access canals, to minimize changes of natural systems and to

minimize adverse impacts on natural areas and wildlife and fisheries

habitat.

Response: While the proposed action would involve the construction

of bifurcated conveyance channels, the channels would serve to

enhance the quality of the wetlands and improve fish and wildlife

habitats.

Guideline 3.13 All pipelines shall be constructed in accordance with

parts 191, 192, and 195 of Title 49 of the Code of Federal Regulations,

as amended, and in conformance with the Commissioner of

Conservation's Pipeline Safety Rules and Regulations and those

safety requirements established by La. R. S. 45:408, whichever would

require higher standards.

Response: Acknowledged.



720
Guideline 3.14 Areas dredged for linear facilities shall be backfilled

or otherwise restored to the pre existing conditions upon cessation

of use for navigation purposes to the maximum extent practicable.

Response: Acknowledged.

Guideline 3.15 The best practical techniques for site restoration and

re-vegetation shall be utilized for all linear facilities.

Response: Acknowledged.

Guideline 3.16 Confined and dead end canals shall be avoided to the

maximum extent practicable. Approved canals must be designed and

constructed using the best practical techniques to avoid water

stagnation and eutrophication.

Response: While the proposed action would involve the construction

of bifurcated conveyance channels, the channels would serve to

reestablish hydrologic connectivity, enhance the quality of the

wetlands, and improve fish and wildlife habitats.

4. GUIDELINES FOR DREDGED MATERIAL DEPOSITION

Guideline 4.1 Spoil shall be deposited utilizing the best practical

techniques to avoid disruption of water movement, flow, circulation

and quality.

Response: The placement of material dredged in association with the

proposed action would not disrupt the movement, flow, circulation, or

quality of water.

Guideline 4.2 Spoil 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. Otherwise, existing spoil disposal

areas or upland disposal shall be utilized to the maximum extent

practicable rather than creating new disposal areas.

Response: Material excavated from construction activities associated

with the removal of the existing dredged material berm along the

ARDC and the railroad grade would be placed in adjacent wetland

areas to create bottomland hardwood (BLH) islands that would serve

as refuges for wildlife during times of flooding. All material dredged

during construction of the conveyance channels would be placed along



721
alternating portions of the channels to also create BLH habitat

"islands. The BLH "islands" would be located to allow sufficient sheet

flow to be conveyed from the swamp.

Guideline 4.3 Spoil shall not be disposed of in a manner which could

result in the impounding or draining of wetlands or the creation of

development sites unless the spoil deposition is part of an approved

levee or land surface alteration project.

Response: The proposed action would not impound wetlands but

would reduce the degree of impoundment that currently exists and

provide for a more natural hydrologic regime by restoring hydrologic

connections.

Guideline 4.4 Spoil shall not be disposed of on marsh, known oyster

or clam reefs or in areas of submersed vegetation to the maximum

extent practicable.

Response: The proposed action would not involve the placement of

spoil on a marsh, oyster or clam reefs, or areas of submerged

vegetation.

Guideline 4.5 Spoil shall not be disposed of in such a manner as to

create a hindrance to navigation or fishing, or hinder timber growth.

Response: The proposed action would not create a hindrance to

navigation or fishing, or hinder timber growth.

Guideline 4.6 Spoil disposal areas shall be designed and constructed

and maintained using the best practical techniques to retain the

spoil at the site, reduce turbidity, and reduce shoreline erosion when

appropriate.

Response: Best management practices would be employed to retain

dredged material and minimize turbidity resulting from dredging

activities.

Guideline 4.7 The alienation of state owned property shall not result

from spoil deposition activities without the consent of the

Department of Natural Resources.

Response: The proposed action would not result in the alienation of

state owned property.



722
5. GUIDELINES FOR SHORELINE MODIFICATION

Guideline 5.1 Non structural methods of shoreline protection shall be

utilized to the maximum extent practicable.

Response: Acknowledged.

Guideline 5.2 Shoreline modification structures shall be designed

and built using best practical techniques to minimize adverse

environmental impacts.

Response: Acknowledged.

Guideline 5.3 Shoreline modification structures shall be lighted or

marked in accordance with U.S. Coast Guard regulations, not

interfere with navigation, and should foster fishing, other

recreational opportunities, and public access.

Response: Acknowledged.

Guideline 5.4 Shoreline modification structures shall be built using

best practical materials and techniques to avoid the introduction of

pollutants and toxic substances into coastal waters.

Response: Acknowledged.

Guideline 5.5 Piers and docks and other harbor structures shall be

designed and built using best practical techniques to avoid

obstruction of water circulation.

Response: The proposed action would not construct any piers, docks,

or other harbor structures.

Guideline 5.6 Marinas, and similar commercial and recreational

developments shall to the maximum extent practicable not be

located so as to result in adverse impacts on open productive oyster

beds, or submersed grass beds.

Response: The proposed action would not construct any marinas or

similar commercial or recreational developments.



723
Guideline 5.7 Neglected or abandoned shoreline modification

structures, piers, docks, mooring and other harbor structures shall

be removed at the owner's expense, when appropriate.

Response: Acknowledged.

Guideline 5.8 Shoreline stabilization structures shall not be built for

the purpose of creating fill areas for development unless part of an

approved surface alteration use.

Response: Acknowledged.

Guideline 5.9 Jetties, groins, breakwaters and similar structures

shall be planned, designed and constructed so as to avoid to the

maximum extent practicable downstream land loss and erosion.

Response: Acknowledged.

6. GUIDELINES FOR SURFACE ALTERATIONS

Guideline 6.1 Industrial, commercial, urban, residential, and

recreational uses are necessary to provide adequate economic

growth and development. To this end, such uses will be encouraged

in those areas of the coastal zone that are suitable for development.

Those uses shall be consistent with the other guidelines and shall, to

the maximum extent practicable, take place only:

a) on lands five feet or more above sea level or within fast lands;

or

b) on lands which have foundation conditions sufficiently stable

to support the use, and where flood and storm hazards are

minimal or where protection from these hazards can be

reasonably well achieved, and where the public safety would not

be unreasonably endangered; and

1) the land is already in high intensity of development use, or

2) there is adequate supporting infrastructure, or

3) the vicinity has a tradition of use for similar habitation or

development

Response: Acknowledged.

Guideline 6.2 Public and private works projects such as levees,

drainage improvements, roads, airports, ports, and public utilities

are necessary to protect and support needed development and shall



724
be encouraged. Such projects shall, to the maximum extent

practicable, take place only when:

a) they protect or serve those areas suitable for development

pursuant to Guideline

6.1; and b) they are consistent with the other guidelines; and c) they

are consistent with all relevant adopted state, local and regional

plans.

Response: Not applicable.

Guideline 6.3 BLANK (Deleted by Louisiana Department of Natural

Resources)

Guideline 6.4 To the maximum extent practicable wetland areas

shall not be drained or filled. Any approved drain or fill project shall

be designed and constructed using best practical techniques to

minimize present and future property damage and adverse

environmental impacts.

Response: No wetlands would be filled for development purposes as a

result of the proposed action. However, the proposed action is intended

to promote the draining of impoundments created by the construction

of the ARDC. The reestablishment of a more natural hydrologic

connectivity would improve the quality of the swamp habitat.

Guideline 6.5 Coastal water dependent uses shall be given special

consideration in permitting because of their reduced choice of

alternatives.

Response: Not applicable.

Guideline 6.6 Areas modified by surface alteration activities shall, to

the maximum extent practicable, be re-vegetated, refilled, cleaned

and restored to their predevelopment condition upon termination of

the use.

Response: The proposed action is intended to promote the draining of

impoundments created by the construction of the ARDC. Revegetation

of degraded swamp through the planting of seedlings is included as

part of the proposed action.

Guideline 6.7 Site clearing shall to the maximum extent practicable

be limited to those areas immediately required for physical

development.

	

725
Response: Acknowledged.

Guideline 6.8 Surface alterations shall, to the maximum extent

practicable, be located away from critical wildlife areas and

vegetation areas. Alterations in wildlife preserves and management

areas shall be conducted in strict accord with the requirements of

the wildlife management body.

Response: The proposed action would not adversely affect habitats on

the Maurepas Swamp Wildlife Management Area, a portion of which is

located within the study area. The proposed action has been

coordinated with the Louisiana Department of Wildlife and Fisheries

and U.S. Fish and Wildlife Service.

Guideline 6.9 Surface alterations which have high adverse impacts

on natural functions shall not occur, to the maximum extent

practicable, on barrier islands and beaches, isolated cheniers,

isolated natural ridges or levees,' or in wildlife and aquatic species

breeding or spawning areas, or in important migratory routes.

Response: The proposed action would not alter barrier islands,

beaches, isolated cheniers, isolated natural ridges or levees. The

proposed action is anticipated to improve the quality of wildlife and

aquatic species breeding/spawning areas through improvement of the

quality of wetland habitats.

Guideline 6.10 The creation of low dissolved oxygen conditions in the

water or traps for heavy metals shall be avoided to the maximum

extent practicable.

Response: By relieving the impoundments currently adversely

affecting the study area, the proposed action is expected to improve the

quality of water in the swamps, including dissolved oxygen conditions.

No traps for heavy metals are anticipated to occur. The proposed action

may temporarily create low dissolved oxygen conditions due to

increased turbidity associated in the immediate vicinity of construction

activities. However, any such conditions would be of short duration

and would return to ambient conditions after construction activities

were completed.

Guideline 6.11 Surface mining and shell dredging shall be carried

out utilizing the best practical techniques to minimize adverse

environmental impacts.




726
Response: Not applicable.

Guideline 6.12 The creation of underwater obstructions which

adversely affect fishing or navigation shall be avoided to the

maximum extent practicable.

Response: No underwater obstructions would result from the

proposed action.

Guideline 6.13 Surface alteration sites and facilities shall be

designed, constructed, and operated using the best practical

techniques to prevent the release of pollutants or toxic substances

into the environment and minimize other adverse impacts.

Response: Acknowledged.

Guideline 6.14 To the maximum extent practicable only material that

is free of contaminants and compatible with the environmental

setting shall be used as fill.

Response: Fill would be native material from adjacent areas. No

contaminants are anticipated to be present.

7. GUIDELINES FOR HYDROLOGIC AND SEDIMENT

TRANSPORT MODIFICATIONS

Guideline 7.1 The controlled diversion of sediment laden waters to

initiate new cycles of marsh building and sediment nourishment

shall be encouraged and utilized whenever such diversion will

enhance the viability and productivity of the outfall area. Such

diversions shall incorporate a plan for monitoring and reduction

and/or amelioration of the effects of pollutants present in the

freshwater source.

Response: The proposed action does not include the controlled

diversion of sediment-laden water.

Guideline 7.2 Sediment deposition systems may be used to offset land

loss, to create or restore wetland areas or enhance building

characteristics of a development site. Such systems shall only be

utilized as part of an approved plan. Sediment from these systems

shall only be discharged in the area that the proposed use is to be

accomplished.



727
Response: Material excavated from construction activities associated

with the removal of the existing dredged material berm along the

ARDC and the railroad grade would be placed in adjacent wetland

areas to create bottomland hardwood (BLH) islands that would serve

as refuges for wildlife during times of flooding. All material dredged

during construction of the conveyance channels would be placed along

the channels, with gaps, to also create BLH habitat "islands. The

BLH "islands" would be located to allow sufficient sheet flow to be

conveyed from the swamp.

Guideline 7.3 Undesirable deposition of sediments in sensitive

habitat or navigation areas shall be avoided through the use of the

best preventive techniques.

Response: Acknowledged.

Guideline 7.4 The diversion of freshwater through siphons and

controlled conduits and channels, and overland flow to offset

saltwater intrusion and to introduce nutrients into wetlands shall be

encouraged and utilized whenever such diversion will enhance the

viability and productivity of the outfall area. Such diversions shall

incorporate a plan for monitoring and reduction and/or amelioration

of the effects of pollutants present in the freshwater source.

Response: The proposed action does not include such diversions.

Guideline 7.5 Water or marsh management plans shall result in an

overall benefit to the productivity of the area.

Response: Acknowledged.

Guideline 7.6 Water control structures shall be assessed separately

based on their individual merits and impacts and in relation to their

overall water or marsh management plan of which they are a part.

Response: The proposed action does not include water control

structures.

Guideline 7.7 Weirs and similar water control structures shall be

designed and built using the best practical techniques to prevent

"cut arounds," permit tidal exchange in tidal areas, and minimize

obstruction of the migration of aquatic organisms.



728
Response: The proposed action does not include water control

structures.

Guideline 7.8 Impoundments which prevent normal tidal exchange

and/or the migration of aquatic organisms shall not be constructed

in brackish and saline areas to the maximum extent practicable.

Response: The proposed action does not include the creation of

impoundments.

Guideline 7.9 Withdrawal of surface and ground water shall not

result in saltwater intrusion or land subsidence to the maximum

extent practicable.

Response: Not applicable.

8. GUIDELINES FOR DISPOSAL OF WASTES

Response: The proposed action would not involve the disposal of

wastes and, therefore, these guidelines are not applicable.

9. GUIDELINES FOR USES THAT RESULT IN THE ALTERATION

OF WATERS DRAINING INTO COASTAL WATERS

Response: The proposed action would not involve the alteration of

waters draining into coastal waters and, therefore, these guidelines are

not applicable.

10. GUIDELINES FOR OIL, GAS, AND OTHER MINERAL

ACTIVITIES

Response: The proposed action would not involve oil, gas, and other

mineral activities and, therefore, these guidelines are not applicable.

Geotechnical investigations will be implemented during the Preconstruction

Engineering, and Design (PED) phase of the LCA ARDC project. This project

is located north of the ARDC, in Livingston Parish. There is only one land

owner in this location, Blind River Properties Inc., owned by Mr. Glen

Martin. We have contacted Mr. Martin to inform him of the proposed

investigations, to which he has no objection. The soil borings needed for this

project shall be 5 inches as required by the COE. To retrieve these samples

the contractor will need an air boat, personal buggy, swamp buggy, and

marsh excavator on site. All of which will be on marsh buggy tracks. These

tracks disperse the weight of the vehicle to minimize adverse impacts on the



729
terrain on which it traverses. A site visit was made with the drilling

contractor to determine and establish the path of least impact for boring

operations. From this site visit boring locations were moved in line with one

another and closer to the spoil bank, some as much as 1,000 feet. This

reduced the amount of unnecessary travel to and from each boring; which will

be made perpendicular to the Diversion Canal and in a direct path as possible

to the next boring. The contractor is not limited to the straightest path, but

the path which is least damaging to the surrounding swamp.

OTHER STATE POLICIES INCORPORATED INTO THE PROGRAM

Section 213.8A of Act 361 directs the Secretary of Department of

Transportation and Development (DOTD), in developing the Louisiana

Coastal resources Program (LCRP), to include all applicable legal and

management provisions that affect the coastal zone or are necessary to

achieve the purposes of Act 361 or to implement the guidelines effectively. It

states:

The Secretary shall develop the overall state coastal management

program consisting of all applicable constitutional provisions, laws and

regulations of this state which affect the coastal zone in accordance with

the provisions of this Part and shall include within the program such

other applicable constitutional or statutory provisions, or other

regulatory or management programs or activities as may be necessary

to achieve the purposes of this Part or necessary to implement the

guidelines hereinafter set forth. The constitutional provisions and other

statutory provisions, regulations, and management and regulatory

programs incorporated into the LCRP are identified and described in

Appendix 1. A description of how these other authorities are integrated

into the LCRP and coordinated during program implementation is

presented in Chapter IV. Since all of these policies are incorporated into

the LCRP, Federal agencies must ensure that their proposed actions are

consistent with these policies as well as the coastal use guidelines

(CZMA, Section 307).

CONSISTENCY DETERMINATION

Based on this evaluation, and the findings of the accompanying Integrated

Feasibility Report and SEIS, the USACE, New Orleans District, has

determined that the proposed is consistent, to the maximum extent

practicable, with the State of Louisiana's Coastal Resources Program.



730


PREPARER

This document was prepared by GEC, Inc., for Dr. William P. Klein, Jr.,

Environmental Analysis Branch, Planning Division, of the New Orleans

District of the U.S. Army Corps of Engineers.

731
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732
733
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734
735
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736
737
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738
739
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740
741
742
Appendix F

INITIATION LETTERS

STATE HISTORIC

PRESERVATION OFFICE

COORDINATION LETTER

PROGRAMMATIC AGREEMENT

743

Inititation Letters

745
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746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
 	

771
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772
773
774
775

Programmatic Agreement

777

779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
Appendix G

RESPONSES TO COMMENTS

807
808
 	







809

# Comment Response

1

Weir at French Settlement does not

function properly and diverts excessive

flow to ARDC, impairing lower Amite

River.

Weir rehabilitation was considered as a measure in

Section 3 of this study (WR-01). Changes to

existing weir would have little effect on restoring

degraded habitat.

2

Project should incorporate weir

construction at downstream end of

ARDC.

Weirs were considered as potential measures, but

were screened out. This process is described in

detail in Section 3 of the report (WC-01 through

WC-08).

3

ARDC construction has disrupted

natural hydrologic regime and damaged

properties.

The objective of this project is to restore hydrologic

connectivity to the area.

4 Endangered/protected species are present

in the study area and vicinity.

Environmental consequences are discussed in detail

in Section 5 of this report.

5 Scope of project should address wildlife

and fisheries habitat.

Environmental consequences are discussed in detail

in Section 5 of this report.

6

H&H modeling should be expansive,

incorporate conditions from other

projects, and/or involve stage data

collection.

Other projects were considered in the Hydrology

and Hydraulics analysis, and the study area chosen

was considered adequate for the purposes of the

analysis needed. The H&H analysis is included in

Appendix L, Section 2.

7 Project should incorporate rehabilitation

of weir at French Settlement.

Rehabilitation does not efficiently contribute to the

accomplishment of the goals for this project. This

was considered as a measure in section 3 of this

study (WR-01)

8 Southwestern boundary of study area

should be expanded.

The study area was increased from NE-1, NE-2,

SE-1 and SE-2 to include areas SW-1 and SW-2.

9 Boat trips to reconnaissance study area

are needed. Several reconnaissance boat trips have been made.

10 Diversion canal stages are primarily

influenced by Lake Maurepas. Modeling shows that this is true.

11 Gap placement is an issue because of

development on dredged material berms.

This was considered as a part of the project, and it

was determined that the maximum benefit could be

achieved without locating the gaps in developed

areas.

12

Swamps south of Bayou Pierre are

impaired from acidity caused by lack of

hydrologic exchange.

Measures describing consideration given to Bayou

Pierre are described in Section 3 (BO-01, BO-02,

CD-02, CS-02, CS-03, CS-04, SR-02)

13 Project is greatly needed and should be

completed on an expedited schedule. We concur.

811
# Comment Response

14 Project should include vegetative

planting or nature control.

These measures are included as a part of the TSP

and are described in Section 3 (VP-01, VP-02).

15

Create hydrologic exchange between

Bayou Pierre and ARDC on south canal

bank.

Measures describing consideration given to Bayou

Pierre are described in Section 3 (BO-01, BO-02,

CD-02, CS-02, CS-03, CS-04, SR-02). No

restorative opportunities exist within the Bayou

Pierre area.

16 Colonial nesting waterbird rookeries are

present in the study area.

Environmental consequences are discussed in detail

in Section 5 of this report.

17 Draining swamp waters may impair

water quality in ARDC and downstream.

No long-term water quality impacts are expected

downstream of this project.

18

Project should operate under flood

events, not merely normal flow or high

flow conditions.

Design will operate in flood conditions.

19

Dredged material berm gapping has been

implemented as part of waterfront

development projects in study area.

Analysis was conducted including existing gaps as

a part of this study, and the recommended plan of

action was to create larger gaps to increase

hydrologic connectivity.

20

Avoidance or minimization of forest

habitat impacts should be considered

during gap location.

The alternates were chosen based on the maximum

net benefit possible, therefore minimization of

impacts was considered.

812
 	 





813

Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-1 October 2010

  	


 

   	

		 	
 



815

Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-3 October 2010

  	

 
 
  	


	
	 	
 



817

Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-5 October 2010

  	

  
 
 	

	  	
 	
  


  	 

  



819

Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-7 October 2010

  	
 
 
   
 	


821
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-8 October 2010

  	

 
   
  
 

  	
 
  
  
   

   

 
 
   
  	
 
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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-9 October 2010

  	

 
   
  
 

  	 


 


 


 
       



 
 
 
 

 


 

 
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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-10 October 2010

  	

 
   
  
 

824
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-11 October 2010

  	

 
   
  
 

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-13 October 2010

  	


 

   	

827
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-14 October 2010

  	

 
   	 

828
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-15 October 2010

  	

 
   	 

  	 

 
 	  
  
 
 
 	 
	    
	   
  
   

     
	  

 
	
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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-16 October 2010

  	

 
   	 

  	 

 
 		    


     
 
   	
 
  	
   	
  		
 
	  
		   	 
   

 
 			    
     	  		 	
	 	  	
 	
 	  	 
 
	    	
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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-17 October 2010

  	

 
   	 

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-19 October 2010

  	



 


 
 	

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-20 October 2010

  	

 
 
	
 	 

834
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-21 October 2010

  	

 
 
	
 	 

835
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-22 October 2010

  	

 
 
	
 	 

836
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-23 October 2010

  	

 
 
	
 	 

837
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-24 October 2010

  	

 
 
	
 	 

838
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-25 October 2010

  	

 
 
	
 	 

839
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-26 October 2010

  	

 
 
	
 	 

840
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-27 October 2010

  	

 
 
	
 	 

841
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-28 October 2010

  	

 
 
	
 	 

842
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-29 October 2010

  	

 
 
	
 	 

843
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-30 October 2010

  	

 
 
	
 	 

844
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-31 October 2010

  	

 
 
	
 	 

 	
 

 Easements will be put into place to restrict forestry activities, as stated inSection 5 of the report. Appendix J of the report contains the Real Estate Plan whichdescribes the easements that will be put into place for the areas of impact. In addition, Section7 of the report stipulates that all compliance and coordination of applicable laws andrestrictions that will be adhered to.

845
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-32 October 2010

  	

 
 
	
 	 

 The FWCAR is discussed in Section 7.2.17 in Volume II of the report. Theupdated version of the FWCAR will be included in all subsequent submittals. Cumulative impacts discussions include similar restoration projects within ornear the study area. These discussions are found throughout Section 5 in Volume II of thereport.

846
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-33 October 2010

  	


 
 	  
  

  	 

 
 		 
 
 


 

 
 
	  
     

 	


 
 	
 
 
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  )# The USACE has coordinated with the LDWF that the proposed actionwould not occur within the Maurepas WMA. Hence, a Special Use Permit would not berequired. The USACE has coordinated with the LDWF that the proposed actionwould not occur within the Blind River Scenic River. Hence, authorization from the LDWF isnot required.

847
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-34 October 2010

  	

   
 
 
  

848
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-35 October 2010

  	


 
 	 	
 

 

 While we recognize that rehabilitation to the weir might benecessary, it was determined that the performance of the weir, with regard to theLCA ARDCM would have little to no effect on restoring the degraded portions ofthe LCA ARDCM study area. During the preliminary phases of the planformulation process, rehabilitation of the weir was considered and subsequentlyscreened out due to a lack of restoration opportunities this measure would provide.In addition, rehabilitation of the weir would fall within operations and maintenanceresponsibility of the local sponsor (Ascension Parish), and would not be within theauthorization of the LCA ARDCM.

849

  	




 	     

 
	
  
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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-39 October 2010

  	


 
 	


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Appendix G Volume II – LCA Amite River Diversion Canal Modification

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-42 October 2010

  	

 

 
 

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-43 October 2010

  	

 

 
 

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-44 October 2010

  	

 

 
 

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-45 October 2010

  	

 

 
 

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-46 October 2010

  	

 

 
 

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-47 October 2010

  	

 

 
 

  	
 	 
	
 	   	   
	 
 

 
 


 
 	  	

  
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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-48 October 2010

  	
 
 
	 	  
 		   	
 	 
 	 
   	 
	 
		 
  

	 
  
	 		 
 	
	 
   	 

 


 	
 
 
 

	
 	 
 

   	 		 
	 	  	
 

  


 	 
 	
 	
 
 	
	 
 
	 
 
  
 	
 
	 	
		   	 
	 	   
	 	
  	
 	 
 

 	   
 


 
	  	   

 	 	 	
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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-49 October 2010

 	 
  
 
  

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Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-50 October 2010

  	

      	

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864
Appendix G Volume II – LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) G-51 October 2010

  	

      	

865

Appendix H

VALUE ENGINEERING REPORT

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Full Report Available Upon Request

883

Appendix I

ADAPTIVE MANAGEMENT/

MONITORING PLAN

885

Louisiana Coastal Area (LCA) Program:

Amite River Diversion Canal Modification

Project

Feasibility-Level Monitoring and Adaptive

Management Plan

July 29, 2010

887

TABLE OF CONTENTS

1.0 INTRODUCTION ....................................................................................................... 1

1.1 Authorization for Adaptive Management in the LCA Program .............................. 1

1.2 Procedure for Drafting Adaptive Management Plans for LCA Projects ................. 1

1.3 LCA Communication Structure for Implementation of Adaptive Management ..... 3

2.0 PROJECT ADAPTIVE MANAGEMENT PLANNING ........................................ 4

2.1 Project Goals and Objectives................................................................................... 5

2.2 Management and Restoration Actions..................................................................... 5

2.3 Conceptual Ecological Model for Monitoring and Assessment .............................. 5

2.4 Sources of Uncertainty............................................................................................. 6

3.0 RATIONALE FOR ADAPTIVE MANAGEMENT................................................... 6

4.0 MONITORING............................................................................................................ 7

4.1 Rationale for Monitoring ......................................................................................... 7

4.2. Monitoring Plan for the Amite River Diversion Canal Modification Project ........ 8

4.2.1 Monitoring Procedures.................................................................................... 10

4.2.2 Use of Monitoring Results and Analyses........................................................ 11

5.0 DATABASE MANAGEMENT ................................................................................ 12

5.1 Description and Location........................................................................................... 12

5.2 Data Storage and Retrieval .................................................................................... 12

5.3 Analysis, Summarizing, and Reporting ................................................................. 12

6.0 ASSESSMENT.......................................................................................................... 13

6.1 Assessment Process .............................................................................................. 13

6.2 Variances and Success ........................................................................................... 13

6.3 Frequency of Assessments..................................................................................... 14

6.4 Documentation and Reporting ............................................................................... 14

7.0 PROJECT CLOSE-OUT ........................................................................................... 14

8.0 COSTS FOR IMPLEMENTATION OF MONITORING AND ASSESSMENT

PROGRAM....................................................................................................................... 15

8.1 Costs for Implementation of Monitoring Program ................................................ 15

9.0 LITERATURE CITED ............................................................................................... 17

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 and Assessment

Program for the LCA Amite River Diversion Canal Modification Project (Alt.33).

List of Attachments

Annex 1. Amite River Diversion Canal Modification Project Conceptual Ecological Model

889

1.0 INTRODUCTION

This document outlines the feasibility-level monitoring and adaptive management plan for the

Louisiana Coastal Area (LCA) Program: Amite River Diversion Canal Modification 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 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 Chief’s 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 objectives...to 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 Memo

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 for the projects

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 Office of Coastal Protection and Restoration (OCPR), 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

891
Image: 2009 Ascension and Livingston Parishes USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: October 2009Scale:Source: USDA/GEC

STUDY AREA AND SUBUNITS

Map ID: 27850108-1780

Little Bayou Chene Blanc

Bayou C hene

B

la

n

c

NW-2

SE-1

SW-2

NE-2 NE-1

SE-2

NE-3

Blind River

Amite River Diversion Canal

New River Canal

Petite Amite River

Chinquapin Canal

NW-1

SW-1

Weir

Old RailroadEmbankment

Laurel Ridge Canal

Flat

Lake

Petite A mite R vi

re

Alligator Bayo u

Bayou An

ot

ni e

Bayou Chene Blanc

New River

O ld River

Petite Amite River

a B you

i P er er

a B

oy

V

u

ci knair

Heath Bayou

1:80,000

0 0.5 1 1.5 2

Miles

Mississippi

Arkansas

Texas

Map Extent

Legend

Study Area Subunits

Figure: 2

892
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.

893
1.3 LCA Communication Structure for Implementation of Adaptive Management

To execute an adaptive management strategy for the LCA Ecosystem Restoration Plan, a

communication structure has been identified (Figure 3). The structure establishes clear lines of

communication between LCA Program Management, an 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 (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 OCPR.

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

894
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

Adaptive Management Framework Team for this project were Tomma Barnes, USACE-MVN ;

Steve Bartell, E2 Consulting Engineers; Laura Brandt, USFWS; Craig Fischenich,

USACE/Engineer Research and Development Center; Barbara Kleiss, USACE Mississippi

Valley Division; Carol Parsons Richards, OCPR; Greg Steyer, USGS National Wetlands

Research Center; and John Troutman, OCPR.

The resulting adaptive management plan for the Amite River Diversion Canal Modification

project describes and justifies whether adaptive management is needed in relation to the

tentatively selected plan (TSP) 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 would demonstrate project success.

The 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 project’s 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 Amite River Diversion Canal Modification 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. Subsequent sections describe monitoring, data

management, and assessment in support of monitoring and adaptive management.

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

preconstruction, engineering, and design (PED) phase, and a detailed monitoring and adaptive

895
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 Amite River Diversion Canal

Modification project. These goals and objectives were subsequently refined through interactions

with the LCA Adaptive Management Framework Team. The overarching goal of the LCA

Program is to contribute toward achieving and sustaining a coastal ecosystem that can support

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

The goal of this project is to reverse the trend of degradation within the western Maurepas

Swamp ecosystem. The swamp has been adversely affected by the construction of the Amite

River Diversion Canal (ARDC) ....The specific restoration objectives of the project are to:

• Increase hydrologic connectivity between the degraded swamp and bottomland

hardwood habitats within the study area and the ARDC by increasing the exchange of

freshwater, sediments, and nutrients.

• Facilitate natural hydrologic cycles within the study area by reducing impoundment in

degraded swamp and bottomland hardwood habitats adjacent to the ARDC which would

improve tree productivity and seedling germination.

• Reduce habitat conversion of swamp to marsh and open water within the study area.

• Improve fish and wildlife habitat within the study area.

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 tentatively selected plan (TSP).

The project TSP is Alternative 33. This alternative has three openings on the north bank of the

ARDC, with the westernmost cut also extending through the railroad grade; three bifurcated

conveyance channels; side casting of dredged material; one cut in the railroad grade north of the

ARDC; and dredged material berm (spoil bank) and swamp floor vegetative plantings.

2.3 Conceptual Ecological Model for Monitoring and Assessment

As part of the planning process, members of the Amite River Diversion Canal Modification

project PDT developed a conceptual ecological model for the swamp ecosystem in the project

area 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

performance measures defined as specific physical, chemical, and biological attributes of the

system.

896
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. There are many uncertainties associated with restoration of

the coastal wetland systems included in the Amite River Diversion Canal Modification project.

Some of the more significant uncertainties include the following:

• Effects of sea-level changes within the project area.

• Effect of subsidence within the project area.

• Effects of hurricanes over the next fifty years.

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 Amite River Diversion Canal

Modification project, an adaptive management program would 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

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

Amite River Diversion Canal Modification project:

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 project’s performance well understood and agreed

upon by all parties?

4) Can project management actions be adjusted in relation to monitoring results?

897
A NO answer to questions 1 through 3 and a YES answer to question 4 identifies the project

as a candidate that could benefit from adaptive management.

Answers to questions 1 through 3 were NO. However, the Adaptive Management Framework

Team determined that the Amite River Diversion Canal Modification project was not a good

candidate for adaptive management because there are no actions that could be taken in response

to monitoring results that the USACE would define as adaptive management actions. That is, the

answer to question 4 is NO. Although some activities could be conducted to adjust project

performance, these actions would not be considered adaptive management activities. O&M for

the selected plan include a yearly inspection of the bank opening locations and conveyance

channels to ensure that there are no flow interruptions, such as from debris or fallen trees, which

could improve project performance. However if monitoring data indicate that actions beyond

yearly O&M (i.e changing the shape, size, branching, or number of conveyances channels or

gaps) would be needed these would be considered structural changes and are beyond the adaptive

management authority. The USACE and State of Louisiana can initiate the process for

developing a new water resources project or pursue a design deficiency under the constructed

project. The Framework Team also considered opportunities for active adaptive management by

designing the project as a management experiment. The Team determined there were minimal

active adaptive management opportunities for the project and that any lessons learned would be

limited and would not likely apply to other coastal Louisiana restoration projects. While there are

currently no apparent adaptive management opportunities, the Adaptive Management Planning

Team can examine the performance of the project in the future. If it is determined during PED

that adaptive management could help achieve any unfulfilled project objectives, the Team can

recommend adaptive management for the project at that time.

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

management. A carefully designed monitoring program is central to properly assessing the

effects of the Amite River Diversion Canal Modification project.

4.1 Rationale for Monitoring

Monitoring must be closely integrated with all other LCA program 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 discern ecosystem responses caused by project

implementation (i.e., management actions) from natural variability. In coastal Louisiana, there

are many existing restoration and protection projects already constructed, and many more are

planned under different authorizations and programs. In combination, these projects will

ultimately influence much of coastal Louisiana. Monitoring must therefore be conducted at

project and system-wide scales to evaluate long-term, large-scale status and trends and shortterm performance.

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

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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 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

monitoring efforts that are underway in coastal Louisiana. For example, the CWPPRA produced

a program that has been monitoring restoration and protection 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 Coast-wide 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

and protection projects in coastal Louisiana. LCA monitoring plans should benefit from existing

monitoring networks to the extent practicable and participate in the implementation of CRMSWetlands. Such participation can maintain the data consistencies necessary to conduct project

assessment and programmatic adaptive management.

4.2. Monitoring Plan for the Amite River Diversion Canal Modification 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 Amite River Diversion Canal

Modification project Monitoring and Assessment 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 Amite River Diversion Canal Modification 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 necessary to evaluate success within the project area. Although the law

allows for a ten-year cost-shared monitoring plan post construction, ten years of monitoring may

not be required. Once ecological success has been achieved, which may occur in less than ten

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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 nonFederal responsibility. This plan estimated monitoring costs for a period of ten years post

construction, because that is the maximum allowed Federal contribution to monitoring. As soon

as ecological success is achieved, monitoring will cease.

The following discussion outlines key components of a monitoring plan that will support

assessment of the project. The plan identifies performance measures along with desired

outcomes and monitoring designs in relation to specific project goals and objectives. Additional

monitoring is identified as supporting information needs that will help to help further understand

and corroborate project effects. The monitoring plan focuses on sampling locations within the

project area in order to make decisions regarding project success. Monitoring sites within the

study area are also proposed for use as reference sites.

Objective 1: Increase hydrologic connectivity between the degraded swamp and bottomland

hardwood habitats within the study area and the ARDC by increasing the exchange of

freshwater, sediments, and nutrients.

Performance Measure 1: Freshwater distribution during operational events

Desired Outcome: Increase hydrologic connectivity and area of extent of freshwater movement

into project area above pre-project conditions.

Monitoring Design: Synoptic hydrologic surveys, using salinity, temperature, dissolved oxygen,

and velocity as tracers, will be conducted during selected low flow and high flow operational

events to track distribution of freshwater. Sampling will be conducted twice annually in the first

three years and as required thereafter.

Objective 2: Facilitate natural hydrologic cycles within the study area by reducing

impoundment in degraded swamp and bottomland hardwood habitats adjacent to the ARDC

which would improve tree productivity and seedling germination.

Performance Measure 2a: Swamp vegetation production and extent

Desired Outcome: Increase in basal area increment of baldcypress & tupelo in the swamp from

existing conditions (existing conditions defined from pre-construction measurements from

CRMS-Wetlands stations and Southeastern Louisiana University historical monitoring)

Monitoring Design: Diameter at breast height (dbh) and overstory tree cover will be measured

in the fall in two pre-construction years and four post-construction years (within the first 10

years).

Performance Measure 2b: Number of baldcypress and tupelo saplings

Desired Outcome: A 25% increase in the number of naturally recruited baldcypress and tupelo

saplings per acre from pre-project conditions ten years after project implementation.

Performance of this measure is most dependent on achieving extended dry periods in the swamp.

Monitoring Design: Understory vegetation (herbaceous, seedling, and sapling) will be measured

in the fall in two pre-construction and four post-construction years (within the first 10 years) to

assess regeneration and changes in cover classes

Performance Measure 2c: Depth, duration and frequency of flooding in the swamp

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Desired Outcome: Increase or decrease from pre-project conditions average flood durations

(existing conditions defined from pre-construction measurements from CRMS-Wetlands

stations)

Desired Outcome: Maintain dry periods (moist soils) in the swamp for a minimum 7-35 days

during summer and early fall for seed germination and maintain water levels below seedling

height to promote seedling survival.

Monitoring Design: Water-level recorders will be deployed in six key areas to measure water

depths at the needed frequencies. Recorders will be established 3 years prior to construction to

determine existing conditions and will be monitored for 10 years post-construction or until

desired outcomes are achieved.

Supporting Information Need: A deep rod-surface elevation table (RSET) rod will be installed

where hydrologic measurements are taken to establish an elevation benchmark.

Objective 3: Reduce habitat conversion from swamp to marsh and open water within the study

area.

Performance Measure 3: Habitat and land:water classification

Desired Outcome: Maintaining immediate pre-construction acreage of baldcypress-tupelo

swamp acreage after 10 years.

Monitoring Design: Habitats will be classified using Landsat Thematic Mapper (TM) scenes

and Digital Orthophoto Quarter Quadrangles (DOQQs) for one pre- and four post-project years

in the study area to assess trends in conversion between swamp, herbaceous marsh, and open

water.

Supporting Information Need: Salinity data will be collected in order to characterize potential

salinity stress associated with low water conditions in the fall, droughts, and intrusions

associated with tropical cyclone events.

Objective 4: Improve fish and wildlife habitat within the study area.

Performance Measure 4: No applicable performance measure

Desired Outcome: Swamp production and hydroperiod measures will be used to assess this

objective.

Monitoring Design: Fish and wildlife habitat is linked to the performance measures associated

with objectives 1-3, focused on improving habitat. Therefore, no specific monitoring is proposed

for this objective.

4.2.1 Monitoring Procedures

The following monitoring procedures will provide the information necessary to evaluate the

objectives for the Amite River Diversion Canal Modification project:

Vegetation: Swamp production, regeneration, and mortality will be assessed at 3 locations

within the project area and 3 reference locations, twice pre-construction and in four postconstruction years. Retention and/or increase of overstory tree cover from pre-project levels will

be determined using a spherical densiometer and hemispherical photography techniques as

described in the CRMS-Wetlands standard operating procedures manual (Folse et al. 2008).

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Densiometer readings and hemispherical photographs will be taken within sampling plots at

fixed time intervals. In order to track the growth of trees within the project and reference areas,

especially baldcypress and tupelo, all trees (i.e., 5 cm dbh) within each 20m x 20m sampling

plot will be identified to species level, tagged with a numbered aluminum tree tag, and the

diameter measured at 4.5 ft above the ground (Folse et al. 2008 and references therein). The dbh

of all tagged trees will be measured at regular fixed intervals at which time both “new” trees (i.e.,

grew to 5 cm dbh from previous sampling time) and dead trees will also be identified. The dbh

data will be used to calculate basal area increment (BAI) which will provide estimates of primary

productivity (Megonigal et al. 1997). BAI is the difference in basal area (calculated from dbh) of

individual trees between sampling times. The understory (i.e., < 5 cm dbh and 50 cm – 137 cm

tall) and herbaceous (i.e., < 5 cm dbh and < 50 cm tall) will be sampled according to Folse et al.

(2008) to determine if baldcypress and tupelo are regenerating.

Hydrology: To determine whether the hydrology in the project area is being restored and

maintained to that of a natural swamp, water level, salinity, temperature, and dissolved oxygen

within the swamp will be measured hourly with datasondes at 3 locations within the project area

and at 3 reference locations for three pre-construction years and up to 10 years post-construction.

The extent of post-construction hydrology measurements will be dependent upon whether

extended dry periods are achieved within initial years following project completion. Each water

level gauge will be surveyed relative to the top of the RSET (NAVD88) and will be serviced

approximately 9 times per year. Duration and frequency of flooding will be calculated using

water levels and the average elevation of the marsh surface. During selected operational events,

synoptic hydrologic surveys will be conducted to track distribution of fresh water. Returning the

hydroperiod of the project area to that of a typical swamp is essential to decreasing the mortality

rate of baldcypress and tupelo trees and increasing biomass and regeneration of these species.

Land:Water and Habitat Classification: Land:water and land cover 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 preproject trends to determine whether conversion of swamp to marsh and open water is being

reduced in the project area. DOQQs of the project area will need to be flown and habitat analysis

completed to capture land cover for one pre-construction and four post-construction years.

4.2.2 Use of Monitoring Results and Analyses

Project monitoring is the responsibility of the OCPR 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.

The results of the monitoring program will be communicated to an Assessment Team that will

use the information to assess system responses to management, evaluate overall project

performance, and construct project report cards as appropriate.

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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.

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 http://www.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 Amite River Diversion

Channel Modification 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. The data managers,

with input from the Adaptive Management Planning Team, 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

project assessment should be identified. The data managers should collaborate with the LCA

Adaptive Management Planning Team in developing a data management plan to support project

assessment.

5.2 Data Storage and Retrieval

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 Data Management Working Group.

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 assessment and

programmatic adaptive management efforts in order to provide reports for the Amite River

Diversion Canal Modification project assessment team, project managers, and decision-makers.

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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 monitoring and

assessment plan.

The results of the Amite River Diversion Canal Modification 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. 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 Amite River Diversion Canal Modification project will

utilize 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 decision making.

The 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 utilized to evaluate

trajectories of change within the project area.

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

904
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 system–wide monitoring effort. Information generated from this effort

should be linked to evaluation of LCA performance and system response. From a project-level

perspective, monitoring plans should be designed to inform adaptive management decisionmaking by providing monitoring data that are relevant to addressing uncertainty.

Similarly, for 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 execute any of the above stated recommendations.

6.3 Frequency of Assessments

Ideally, the frequency of assessments for the Amite River Diversion Canal Modification project

would be determined by the relevant ecological scales of each performance measure. The

project’s technical support staff will identify for each performance measure the appropriate

timescale for assessment. The project should have a combination of short-, medium-, and longterm 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 Amite River

Diversion Canal Modification project. The Assessment Team will work with the project

monitoring team and monitoring workgroup to produce an annual Amite River Diversion Canal

Modification project report card 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 PROJECT CLOSE-OUT

Close-out of the project would occur when it is determined that the project objectives have been

attained or when the maximum ten-year monitoring period has been reached. Success would be

considered to have been achieved when the following objectives have been met, or when it is

clear that they will be met based upon the trends for the site conditions and processes:

• Pre- and post-construction comparison of survival rates of regenerated species

• Hydrologic connectivity

• Swamp regeneration

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.

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8.0 COSTS FOR IMPLEMENTATION OF MONITORING AND

ASSESSMENT PROGRAM

The costs associated with implementing the LCA 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 and monitoring and assessment elements, the costs estimated in Table 1 (below) will be

refined in the PED phase during the development of the detailed monitoring and assessment

plan.

8.1 Costs for Implementation of Monitoring Program

Costs to be incurred during the PED phase include monitoring site construction and

establishment and two years of pre-construction and construction data acquisition that establish

baseline conditions. Cost calculations for post-construction monitoring are displayed as annual

costs and as a ten year (maximum) total. If ecological success is determined earlier (prior to 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. All data collection activities follow

consistent and standardized processes regardless of the organization responsible for monitoring.

Cost estimates include monitoring equipment, monitoring station establishment, data collection,

quality assurance/quality control, data analysis, assessment, and reporting for the proposed

monitoring elements 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 and assessment program for this project is $2,971,200. Unless otherwise noted, costs

will begin at the onset of the PED phaseand will be budgeted as construction costs.

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Table 1. Preliminary Cost Estimates for Implementation of the Monitoring and

Assessment Program for the LCA Amite River Diversion Canal Modification Project (Alt.

33).

Category Activities

1 yr

PED Set-up &

Data

Acquisition

1 yr

Construction

10 yr PostConstruction Total

Monitoring:

planning and

management

Monitoring workgroup,

drafting detailed

monitoring and

assessment plan during

PED, working with PDT

on performance measures

$119,000 $16,800 $194,500 $330,300

Monitoring:

data collection

Landrights, site

construction, and

surveying

$80,800 $80,800

Vegetation $20,000 $28,700 $94,900 $143,600

Hydrology $70,700 $72,500 $837,500 $980,700

Land:Water $6,700 $6,800 $79,000 $92,500

Habitat classification $16,400 $77,900 $94,300

Water quality $13,500 $13,900 $160,500 $187,900

Database

Management

Database development,

management, and

maintenance; webpage

development for

communication of data to

stakeholders

$20,500 $21,100 $243,100 $284,700

Assessment $243,100 $243,100

TOTAL $420,800 $193,400 $2,357,000 $2,971,200

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9.0 LITERATURE CITED

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.

Megonigal, J.P., W.H. Conner, S. Kroeger, and R.R. Sharitz. 1997. Aboveground production in

southeastern floodplain forests: A test of the subsidy-stress hypothesis. Ecology 78(2):370-384.

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 Amite River Diversion Canal Modification 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 Functions 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

910
2

(e.g., planning and operations), and 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.

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3

1.2.4 Science, Monitoring, and Adaptive Management

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

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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

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). Like the plan formulation process, the LCA team recognizes

that CEM development 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.

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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 systemwide 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 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

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2.1 Methodology

A CEM was developed for the Amite River Diversion Canal Modification 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 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 assessment 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 Amite River Diversion Canal Modification project was identified as a near-term critical

feature in the Louisiana Coastal Area (LCA),Louisiana - Ecosystem Restoration Study (2004

LCA Plan) (USACE 2004a). The 2004 LCA Plan was recommended to the 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. The

Amite River Diversion Canal Modification project was included in that plan along with nearterm critical restoration features throughout coastal Louisiana. Including the Amite River

Diversion Canal Modification 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 some of 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 restoring baldcypress-tupelo swamp

habitat near the Amite River Diversion Canal by constructing gaps in the spoil banks that border

the canal. 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 following project implementation 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 Amite River Diversion Canal Modification project is to reverse the trend of

degradation in the western portion of the Maurepas Swamp, so as to contribute toward achieving

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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 habitat conversion and future land loss;

Establish hydrologic connectivity to allow seasonal drying in which the swamps are

drained to promote seedling germination, establishment, and survival;

Introduce nutrients and sediment to swamps;

Promote water circulation to improve water quality (including salinity reduction);

Increase swamp vegetation productivity;

Restore and preserve fish and wildlife habitat; and

Protect vital socioeconomic resources including cultures, community, infrastructure,

business and industry, and flood protection features.

2.2.2 Project Description

The study area is located in LCA Subprovince 1 in Livingston and Ascension parishes, in the

vicinity of Head of Island, Louisiana, encompassing portions of Louisianas Sixth and Third

Congressional Districts (Figure 2). The study area contains approximately 19,000 acres of

baldcypress-tupelo swamp habitat in the western Maurepas Swamp. The study area includes the

Amite River Diversion Canal, a 10.6-mile-long flood control channel between the Amite and

Blind rivers. Dredged material excavated during channel construction was deposited in spoil

banks on either side of the canal. These spoil banks have disrupted the natural hydrologic regime

in the study area. Prior studies have documented degradation in the baldcypress-tupelo swamp

adjacent to the diversion canal and have demonstrated a need for ecosystem restoration of this

swamp habitat through the reintroduction of a natural hydrologic regime. The proposed project

involves restoration of impaired swamp habitat within the study area by gapping the spoil banks

along the diversion canal to promote hydrologic exchange between flows within the diversion

canal and the adjacent swamp habitat. Gapping the banks of other waterbodies and a relict

railroad grade that transects the study area were also evaluated as part of the proposed project.

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Figure 2. Amite River Diversion Canal Modification Project Study Area.

3.0 CONCEPTUAL ECOLOGICAL MODEL DISCUSSION

The CEM developed for the Amite River Diversion Canal Modification project is presented in

Figure 3. Model components are identified and discussed in the following subsections.

3.1 Drivers

3.1.1 Canal Construction

The Amite River Diversion Canal is a 10.6-mile-long channel that extends from the Amite River

at Mile 25 to Mile 4.8 of the Blind River. Construction of the canal was authorized by Senate

Report No. 1029 (89th Congress, 1st Session), which authorized construction of improvements on

the Amite and Comite rivers and Bayou Manchac, Louisiana, in the interest of flood control and

major drainage. The canal was constructed in accordance with provisions of the U.S. Army

Corps of Engineers (USACE) New Orleans District publication Survey of Amite River and

Tributaries, Louisiana (USACE 1955), which was conducted under the authority of the Flood

Control Act of 1944. The survey report recommended the construction of a diversion channel for

the Amite River with a length of 10 miles, extending from Mile 25 of the Amite River to Mile 5

of the Blind River. Construction of the Amite River Diversion Canal was completed in October

1963. Dredged spoil generated in the construction of the canal was placed in two spoil banks on

either side of the canal. These spoil banks form topographic high points within the study area.

Because of an inadequate understanding of the natural systems operating within the study area,

construction of the Amite River Diversion Canal has had unforeseen, adverse environmental

effects. Canal construction has altered physical defining characteristics, including water storage,

sheet flow, and nutrient and sediment input levels within the baldcypress-tupelo swamp habitat

in the study area.

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3.1.2 Hurricanes

Coastal storms, particularly tropical cyclone events, also 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 14 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 1851-2007, and at least 52 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.

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Figure 3. Conceptual Ecological Model, LCA Amite River Diversion Canal Modification Project.

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Principal impacts to the study area as a result of tropical cyclone events are windfall mortality

and storm surges originating from Lake Maurepas. Windfall mortality typically exerts the

greatest impact upon mature or diseased trees, sparing younger, healthier specimens. Storm

surges exert a considerably greater and more widespread stress upon vegetation through the

introduction of storm surge waters that exhibit higher salinity concentrations than are present in

surface waters within the study area. The four hurricanes identified above each resulted in

measurable storm surges within the study area. Water gage data collected from a U.S. Geological

Survey (USGS) monitoring station on the Amite River at Louisiana Highway (LA-) 22 and from

Louisiana Department of Natural Resources (LDNR) gages established in the eastern study area

in 2005 recorded storm surges from hurricanes Katrina and Rita that inundated the Amite River

Diversion Canal within the study area at an average of 2.0 and 3.3 feet above mean annual water

level, respectively. Water gage data collected from the USGS monitoring station on the Amite

River at LA-22 recorded storm surges from hurricanes Gustav and Ike within the study area at an

average of 3.2 and 4.4 feet above the 2007 mean annual water level, respectively.

3.2 Ecological Stressors

3.2.1 Impoundment

The placement of dredged material in spoil banks along either side of the Amite River Diversion

Canal disrupted sheet flow within the study area and formed topographic high points that

prevented the drainage of baldcypress-tupelo swamps into waterbodies within the study area

during intervals of low surface flow. This activity, in conjunction with the construction of other

features, such as the relict logging railroad grade that traverses the eastern study area from north

to south, resulted in the permanent impoundment of baldcypress-tupelo swamp habitat within the

study area.

Swamp impoundment is particularly pronounced in the eastern portion of the study area (i.e.,

east of the Petite Amite River), as demonstrated by hydrograph data collected in 2005 in this area

for a Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) project nominee for

the Priority Project List (PPL) 16, Hydrologic Restoration in the Swamps West of Lake

Maurepas. Approximately 11 months of water gage data were collected in the eastern study area

from three water gages that were set within the Amite River Diversion Canal and inundated

swamp habitat on the left descending bank. The results of this data collection analysis, as

presented in Shaffer et al. (2006), indicate that the swamp habitat along the left descending bank

of the diversion canal in the eastern study area is impounded; water levels within this area never

receded below 2.2 feet above mean sea level (msl), including periods in which water levels

within the canal receded below that level.

Impoundment within the study area has resulted in decreased water quality and increased

seedling mortality, which in turn has resulted in increased habitat conversion to marsh and open

water (see Section 3.3 for additional discussion).

3.2.2 Lack of Riverine Input

Historically, hydrologic conditions within the study area were dominated in the north and west

by the Amite River, in the south by overbank flow from the Mississippi River, and in the east by

tidal influence from Lake Maurepas. Periodic flooding of the Amite and/or Mississippi rivers

resulted in the inundation of baldcypress-tupelo habitat within the study area. Flooding occurred

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within the study area and vicinity on a cyclical basis, with peak water elevations in the late

spring or early summer. As floodwaters receded, surface waters in the study area were conveyed

eastward via sheet flow until they were received by Bayou Chene Blanc or the Blind River, by

which they were conveyed to Lake Maurepas.

The implementation of flood control projects from the early to mid-20th century, including the

channelization of the Amite River, construction of flood protection levees on the Mississippi

River, and especially the construction of the Amite River Diversion Canal, disrupted the natural

hydrologic regime within the study area. River channelization and levee construction greatly

reduced overbank flooding in the study area, causing a loss of nutrients and sediments in the

ecosystem, decreased water quality, and increased subsidence (see Section 4.3 for additional

discussion).

3.2.3 Storm Surge

Tropical cyclone events exert a stochastic but severe stress upon the swamp habitat through

salinity spikes associated with saline storm surge events (see Section 3.3 for additional

discussion). The introduction of saline storm surge water into the impounded swamps results in

reduced biomass production and impaired health, which in turn causes increased tree mortality,

decreased soil production and integrity, and a consequent increase in relative subsidence (see

Section 3.3 for additional discussion). Periodic influxes of saline storm surge waters remain

trapped in the impounded swamps, resulting in stochastic but periodic cumulative increases in

salinity in impounded waters and soils in the study area. Saline storm surge waters become

impounded in the swamp by the spoil banks that border the Amite River Diversion Canal and is

not allowed to drain out the swamps during seasonal low flow events or to be flushed out by

seasonal river bank overflow events. Saltwater introduction into formerly freshwater wetlands

has been demonstrated to reduce photosynthetic rates of baldcypress and water tupelo and reduce

productivity of swamp forest tree species and other freshwater vegetation.

3.3 Ecological Effects

3.3.1 Increased Seedling Mortality

Increased seedling mortality is a biological response to the impoundment produced in the study

area by the spoil banks that border the Amite River Diversion Canal (see Section 4.2.1). Seedling

germination and establishment is an essential component for ensuring the sustainability of

baldcypress-tupelo swamp habit through the replacement of trees lost to windfall mortality or

disease. However, baldcypress and tupelo seedling establishment is currently impaired within the

study area as a result of the persistent flooding conditions that result from impoundment

(CWPPRA Task Force 2002).

Souther and Shaffer (2000) reported that in the early 20th century, baldcypress swamps were

harvested en masse in coastal Louisiana, and that in many harvested areas, natural regeneration

did not occur; instead, these areas converted to marsh or open water. The study concluded that

prolonged flooding or complete submergence within the swamps may have suppressed

germination or growth rates of young seedlings and even caused mortality (see Section 3.3.1).

Neither baldcypress nor tupelo seeds can germinate when flooded (Hamilton and Shaffer 2001).

Seeds of both species remain viable when submerged in water and can germinate readily when

floodwaters recede (Kozlowski 1984). However, the seedlings require seasonal drying periods,

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and the substrate compaction associated with these drying periods, for their root systems to

become properly established in the swamp substrate. With minimal ability to drain and persistent

flooding, the typical seasonal drying of the swamp does not usually occur, leading to failure of

seedlings to establish themselves and replace older trees that have been lost to other natural

processes (CWPPRA Task Force 2002).

3.3.2 Loss of Nutrients and Sediments

Loss of nutrients and sediments is a physical response to the lack of riverine input caused by the

construction of the Amite River Diversion Canal (see Section 3.2.2). Effler et al. (2006)

examined the importance of nutrient influxes that accompany freshwater diversions or other

hydrologic connectivity projects to swamp productivity. Nutrient augmentation of baldcypress

and tupelo trees in the Maurepas Swamp (similar to nitrate loading rates expected from a small

freshwater diversion) increased radial growth of both species (especially baldcypress) in

degraded forest stands. Nutrient augmentation also increased nitrogen in foliage for both tree

species. These findings support hypotheses that swamps in southeastern Louisiana are nutrientlimited, and existing trees can utilize, benefit, and act as nutrient sinks for nutrient-laden river

water accompanying diversions.

Further evidence of nutrient starvation within the study area was identified in Shaffer et al.

(2001). This study determined the nutrient augmentation significantly enhanced (by about 33

percent) biomass production of herbaceous vegetation at monitoring stations within the western

Maurepas Swamp during 2000. Furthermore, several studies conducted over the last decade have

demonstrated that nutrient augmentation to baldcypress seedlings doubles growth rates in the

western Maurepas Swamp (Boshart 1997, Forder 1995, Greene 1994, Myers et al. 1995), further

indicating that the baldcypress-tupelo swamp in the study area and vicinity is nutrient-limited.

Shaffer et al. (2008) presented data at the Society of Wetland Scientists meeting on tree growth

in the Maurepas Swamp. For the period 2000-2007, diameter growth was measured for over

1,800 trees. Diameter growth in the measured trees was significantly less than established growth

levels for trees in healthy freshwater swamp systems. The study determined that in interior

swamp locations such as the study area, the primary factor inhibiting diameter growth was

nutrient-poor stagnant standing water and the lack of nutrient-rich freshwater throughput caused

by the loss of hydrologic connectivity with riverine systems.

3.3.3 Decreased Water Quality and Increased Salinity

Decreased water quality and increased salinity is a chemical response to both the impoundment

produced in the study area by the spoil banks that border the Amite River Diversion Canal (see

Section 3.2.1) and the introduction of saline storm surge waters associated with tropical cyclone

events (see Section 3.2.3). The Maurepas Swamp is characterized by nutrient-poor surface

waters. Day et al. (2001) conducted a water quality analysis in support of CWPPRA Project PO29 Mississippi River Reintroduction into Maurepas Swamp. The observed concentrations of

nitrate, ammonium, and nitrogen at surface water sampling stations within the western Maurepas

Swamp were all reduced with respect to observed concentrations in the Mississippi River. The

results of sampling of water quality parameters shows that for some nutrient forms, the Maurepas

basin has relatively low nutrient concentrations compared to the Mississippi River and other

systems studied. The results of this study indicate that the baldcypress-tupelo swamp within the

study area and vicinity is severely nutrient-limited.

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In addition, the trees are highly stressed, which appears to decrease productivity, increase

mortality, and increase susceptibility to herbivory and parasites. Saltwater intrusion has

increased in this general area, at least in part due to a combination of net subsidence and the lack

of riverine freshwater inputs. Saltwater intrusion events observed in the western Maurepas

Swamp in 1999 and 2000 caused greater than 97 percent mortality in planted baldcypress

seedlings in the northwestern portion of the swamp (USACE 2004a). Salinity of three parts per

thousand (ppt) can reduce growth of both baldcypress and tupelo saplings (Pezeshki 1990); and

when combined with flooding stress, growth reduction in baldcypress was substantial. Clearly

salinity can be a significant factor contributing to swamp deterioration, especially combined with

other stressors (e.g., flooding, herbivory). Low-salinity water has been noted in the swamps north

and south of the Amite River Diversion Canal (CWPPRA Task Force 2002).

The western Maurepas Swamp is characterized by saltwater intrusions that occur mostly during

low-water periods in the fall (Shaffer et al. 2001). The mean salinity of the lake water measured

at the Manchac Bridge also has increased gradually since 1951 (Thomson 2000), indicating that

salinity levels appear to be increasing in the region. Additionally, storm surges originating from

Lake Maurepas associated with tropical cyclone events exert a stochastic but severe stress upon

the swamp habitat through salinity spikes in surface waters within the swamp. Recent tropical

cyclone events, occurring at a rate of one to two per year, have produced measurable spikes in

salinity within the western Maurepas Swamp (USACE 2004a). These salinity spikes are in turn

exacerbated by the impoundment produced within the study area by the spoil banks that border

the Amite River Diversion Canal. The CWPPRA PPL 12 Environmental Work Group concluded

that the spoil banks appeared to restrict the ability of higher salinity water to be flushed from the

system once it finds its way in (CWPPRA Task Force 2002). Storm surge waters currently

remain trapped in the impounded swamps, resulting in stochastic but periodic cumulative

increases in salinity in impounded waters and soils in the study area.

3.3.4 Decreased Productivity

Decreased productivity in vegetative communities in the study area is a biological response to

the lack of riverine input caused by the construction of the Amite River Diversion Canal and the

consequent loss of nutrients and sediments (see Sections 3.2.2 and 3.3.2). Comparison of

productivity in swamps that are either managed, have more favorable hydrology, and/or are

receiving nutrient enrichment suggest that the existing levels of productivity in the Maurepas

Swamp are as low as 50 percent or even 25 percent of average values.

As part of the CWPPRA PPL 11 effort to launch a project diverting Mississippi River water into

the Maurepas Swamp, Shaffer et al. (2001) examined woody and herbaceous vegetation at 20

study sites, each with two 625-square-meter (m2

) permanent stations, in the southern Maurepas

Swamp, including several along the Amite River Diversion Canal near its eastern terminus.

Within each of the forty 25-meter by 25-meter (625 m2

) permanent stations, four 4-meter by 4-

meter (16 m2

) permanent herbaceous plots were established. Cover values were obtained by two

independent estimates for all 160 plots from mid-June to early July and again in early September

of 2000. To measure annual production, herbaceous (understory) primary productivity was

estimated within one fertilized and one unfertilized herbaceous (4-meter by 4-meter) plot by

clipping two randomly chosen (non-repeating) replicate subplots (of 0.25 m2 area) twice during

the growing season. Tree health and primary productivity were determined through the collection

of annual litter. Annual tree diameter growth was measured to estimate wood production and

calculate basal wood area per hectare of swamp. The measured tree diameters in each plot were

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then converted into basal wood area, summed and multiplied by 16 (as there are sixteen 625-m2

plots to a hectare) to estimate the total area of basal wood per hectare for each plot for each of

the 40 stations. Five litter traps were randomly installed at each of two 625-m2 plots at 40

stations throughout the Maurepas Swamp, yielding a total of 200 litter traps deployed. The study

concluded that salinity is an important stressor in the Maurepas Swamp, but that degradation of

tupelo trees within the swamp has been occurring for decades and is almost certainly primarily

due to altered hydrology and lack of throughput. The study determined that the low soil bulk

densities and high soil organic matter content throughout much of this swamp are indicative of a

lack of riverine influence. The results of the study indicated that all measures of ecosystem

health collected in the southern Lake Maurepas region indicate that these swamps are highly

degraded and would benefit from a substantial infusion of nutrients and freshwater from a river

diversion. One drawback of this study, however, is that data were collected during the drought

years of the late 20th and early 21st centuries, and may therefore be atypical of normal baseline

conditions and responses to flooding of the swamp.

Results of studies in wetlands receiving secondary treated sewage suggest that introduction of

nutrients as well as sediments from river water could stimulate production by 300 to 500 percent

(Rybczyk et al. 2002, Hamilton and Shaffer 2001).

3.3.5 Increased Habitat Conversion

Increased habitat conversion to marsh and open water is a physical and biological response to

both impoundment and the resulting increased seedling mortality (see Sections 3.2.1 and 3.3.1)

and lack of riverine input and the resulting loss of nutrients and sediments and decreased

productivity in vegetation communities (see Sections 3.2.2, 3.3.2, and 3.3.4). Hoeppner et al.

(2007) concluded that the majority of the Maurepas Swamp is stressed and seems to be on a

trajectory of slow degradation leading to a gradual conversion to marsh and open water. Stagnant

flooding and nutrient deprivation appear to be the largest stressors in the swamp interior, while a

combination of increased salinity, flooding stress, and nutrient deprivation is killing large

proportions of the trees located along the lakeshore, particularly along the eastern margin of

Lake Maurepas.

Natural regeneration throughout the Maurepas Swamp is very low and even absent at most sites.

Land conversion observations on the Manchac land-bridge and Jones Island demonstrate what is

expected in the Maurepas Swamp in the coming decades, if no restoration action is taken. In

1956, most of the area of the Manchac land-bridge was dominated by second-growth swamp. By

1978, much of this swamp had converted to marsh and shrub-scrub, and by 1990 the marsh had

begun to break up and to convert to open water (Barras et al. 1994).

Consequently, it is expected that without restoration, the factors and processes that are

contributing to stress and deterioration of the swamps in the vicinity of the Amite River

Diversion Canal will continue and will result in loss of the swamp, with succession to open

water. The remaining portion of the western Maurepas Swamp is composed of approximately 65

percent tupelo trees and 35 percent baldcypress trees, and as of 1990, covered an area within the

Amite/Blind Rivers mapping unit of about 138,900 acres of swamp and 3,440 acres of fresh

marsh (CWPPRA Task Force, 2002). The wetland loss rates for the Amite/Blind Rivers mapping

unit for 1974-90 were estimated by USACE to be 0.83 percent per year for the swamps, and 0.02

percent per year for fresh marsh. Based on these rates, approximately 50 percent (or 69,450

acres) of swamp and 1.2 percent (or about 40 acres) of fresh marsh will be lost within 60 years

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(CWPPRA Task Force 2002). The USACE determined that, based on the low tree density,

degraded condition, and expectation for mortality, the majority of swamp habitat within the

study area will degrade to less than 33 percent canopy cover within 20 years (USACE 2004b ).

Under the continued influence of these conditions, tree mortality will continue to increase and

tree density will continue to decline, until most swamp habitat in the vicinity of the Amite River

Diversion Canal converts to fresh marsh. Monitoring studies conducted for the CWPPRA PPL

12 proposal indicated that conversion of baldcypress-tupelo swamp to fresh marsh is already

occurring in the study area, particularly north of the diversion canal in the eastern study area

(CWPPRA Task Force 2002). The results of these monitoring studies indicate that many areas of

interior swamp in the study area and vicinity that exhibit significantly stressed or dying overstory

vegetation also contain bulltongue or arrow arum as understory vegetation. Additionally, the

monitoring results indicate that many areas of bulltongue marsh in the greater southern Maurepas

Swamp have converted to fragile spikerush flotant. Factors contributing to this conversion

include the much greater tolerance of baldcypress and water tupelo with respect to herbaceous

understory vegetation for long-term deep inundation, and the increasingly unconsolidated nature

of swamp substrate caused by the reduction of below-ground productivity. Consequently, it is

expected that the vast majority of swamp habitat adjacent to the Amite River Diversion Canal

would convert to open water rather than stable marsh habitat without implementation of the

proposed project.

3.3.6 Increased Subsidence

Increased subsidence is a physical response to lack of riverine input and the resulting loss of

nutrients and sediments and decreased productivity in vegetation communities (see Sections

3.2.2, 3.3.2, and 3.3.4). The soil characteristics within the western Maurepas Swamp are

indicative of a lack of riverine influence as evidenced by high soil organic matter content and

low bulk density values (DeLaune et al. 1979, Hatton 1981, Messina and Conner 1998). Soil

building within the Maurepas Swamp occurs almost exclusively as a result of organic

productivity; in the swamps adjacent to the diversion canal, this productivity is substantially

depressed compared to normal conditions (CWPPRA Task Force 2002). Subsidence in this area

is classified as intermediate, at about 1.1 to 2 feet per century (USACE 2004a). With minimal

soil building and moderately high subsidence, there has been a net lowering of ground surface

elevation, leading to a doubling in flood frequency over the last four decades (Thomson 2000),

so that the swamps are now persistently flooded.

Shaffer et al. (2003) conducted a subsidence investigation in the Maurepas Swamp immediately

southeast of this projects study area in support of CWPPRA project PO-29 Mississippi River

Reintroduction into Maurepas Swamp. Subsidence rates for the PO-29 project area were

measured by the installation of two surface elevation tables at 13 representative study sites. The

tables could be set in four compass directions and utilized the mean value of nine pin readings of

soil elevation. Readings were collected during the interval October-November 2001 and

compared against readings collected in October-November 2002 to provide an accurate estimate

of the net subsidence rates within the Maurepas Swamp. The results of this subsidence

investigation indicate an average net elevation decrease of slightly less than one centimeter for

the study area during the interval between sampling, although actual rates varied considerably by

habitat type.

3.4 Attributes and Performance Measures

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3.4.1 Land Cover

Land cover has been identified as a key indicator of project success with respect to preventing

habitat conversion and future land loss. Comparison of pre-project land cover characteristics

with post-project land cover characteristics would serve to determine if conversion of

baldcypress-tupelo swamp to freshwater marsh or open water within the study area experiences a

post-project decline or ceases altogether. Additionally, post-project land cover analysis would

determine if areas within the study area that had previously converted to freshwater marsh or

open water experience undergo a post-project reversion to baldcypress-tupelo swamp as a result

of improved seedling survival.

Spatial analysis has been identified as an assessment 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 baldcypresstupelo swamp coverage within the study area.

A post-project relative increase in the total area of baldcypress-tupelo swamp would be an

indication of significant project success, while a post-project stabilization of baldcypress-tupelo

swamp coverage within the study area would be an indication of moderate project success.

Conversely, a post-project decline in baldcypress-tupelo swamp coverage within the study area

would indicate that the project did not succeed in preventing habitat conversion and, by

extension, future habitat loss.

3.4.2 Vegetation Productivity

Swamp vegetation productivity has been identified as a key indicator of project success.

Comparison of pre-project vegetation monitoring data with post-project vegetation monitoring

data would serve to determine if biomass production in plant communities within the study area

increases in response to project features. A post-project increase in biomass production would

also indicate the introduction of nutrients and sediment into the swamps as a result of the project.

Three assessment performance measures have been identified for this attribute, including percent

cover, diameter at breast height (dbh) and litterfall.

Percent cover is the estimated percentage of the ground surface covered by vegetation.

Canopy percent cover is the estimated percentage of the ground surface covered by tree

canopies when the crowns are projected vertically. A high percent cover is indicative of

significant productivity within the respective vegetation communities, and a higher

canopy percent cover is indicative of significant productivity within woody species.

Diameter at breast height (dbh) is the measurement of tree diameter at a height of 4.5

feet above the forest floor on the uphill side of the tree. A large annual increase in dbh is

indicative of significant productivity with respect to the measured tree and adjacent forest

community. Ongoing monitoring studies of baldcypress and tupelo trees within the

western Maurepas Swamp by Dr. Gary Shaffer indicate that average annual dbh increase

for trees within the eastern study area is approximately one millimeter per year, a growth

level that is significantly lower than expected levels of 1-2 centimeters per year for

healthy baldcypress or tupelo trees (Shaffer, personal communication 2009).

Litterfall is the measurement of the movement of leaves, twigs, and other forms of

organic matter from the biosphere to the litter layer found in soil via interception in

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collection traps. Large volumes of litterfall are indicative of significant biomass

production within the constituent forest community.

A post-project relative increase in productivity within the study area as evidenced by these three

measures would be an indication of significant project success, while a post-project stabilization

of these measures would be an indication of moderate project success. Conversely, a post-project

decline in these measures within the study area would indicate that the project did not succeed in

increasing swamp vegetation productivity.

3.4.3 Elevation

Ground surface elevation has been identified as a key indicator of project success with respect to

reducing or reversing subsidence within the study area. Comparison of pre-project elevation

levels with post-project elevation levels would serve to determine if sediment input and soil

accretion is occurring within the study area in response to project features. A post-project

increase in elevation would implicitly indicate the introduction of nutrients and sediment into the

swamps as a result of the project, and would also indicate an increase in vegetation productivity

and the resulting litterfall that is a principal factor in soil accretion within the Maurepas Swamp.

Two assessment 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.

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.

Post-project increases in 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 stabilization of elevation as evidenced by these measures

would be an indication of moderate project success. Conversely, a post-project decline in

elevation within the study area would indicate that the project did not succeed in offsetting

subsidence and, by extension, habitat conversion and future land loss.

3.4.4 Water Quality

Surface water quality in interior locations in the study area has been identified as a key indicator

of project success with respect to establishing hydrologic connectivity between the Amite River

Diversion Canal and the adjacent swamp habitat. Comparison of pre-project water quality with

post-project quality would serve to determine if freshwater throughput is introducing nutrients

and flushing out saline waters within the study area in response to project features. A postproject improvement in water quality would implicitly indicate the introduction of freshwater

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and the associated nutrients and sediment into the swamps as a result of the project. Four

assessment performance measures have been identified for this attribute, including total

suspended solids (TSS), dissolved oxygen (DO), nutrients, and salinity.

Total suspended solids (TSS) is a measurement of the total volume of sediment and other

solids suspended in a given volume of water. Because surface waters within the swamps

adjacent to the Amite River Diversion Canal are hydrologically isolated from other

waterbodies in the study area, TSS concentrations within swamp surface waters are

expected to be lower than those of nearby waterbodies.

Dissolved oxygen (DO) is a relative measure of the amount of oxygen that is dissolved in

a given volume of water. Surface waters within the swamps in the study area are expected

to exhibit lower DO concentrations than those of nearby waterbodies, because water

movement (which exposes surface water to a greater volume of air through lateral

movement and results in greater dissolution of oxygen) is virtually nonexistent in the

swamps.

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. Surface waters within the swamps adjacent to the

Amite River Diversion Canal have been demonstrated to be nutrient-poor with respect to

other waterbodies in the area because the hydrology prevents the accumulation of

nutrients from surface runoff.

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

other area waterbodies because saline storm surges introduced into the swamps during

tropical cyclone events become trapped in the impounded swamps and are not allowed to

drain out of the study area.

Post-project improvements in water quality within the study area as evidenced by analyses 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 reestablishing riverine input to the study area and the resulting reintroduction of

nutrients and sediments associated with freshwater throughput.

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.

Barras, J.A., P.E. Bourgeois, and L.R. Handley. 1994. Land loss in coastal Louisiana, 1956-

1990. National Biological Survey, National Wetlands Research Center Open File Report 94-01.

Lafayette, LA.

Boshart, W.M. 1997. The conservation and restoration of a baldcypress swamp: an investigation

of macronutrients, competition, and induced vegetation dynamics as related to nutria herbivory.

M.S. Thesis. Southeastern Louisiana University, Hammond, LA.

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CWPPRA Task Force. 2002. Wetland Value Assessment Project Information Sheet, Revised

October 2002, Hydrologic Restoration in the Swamps West of Lake Maurepas- Amite River

Diversion Canal Spoil Bank Gapping. In: CWPPRA Task Force, 12th Priority Project List Report

(Appendices).

Day, J.W., R.R. Lane, G.P. Kemp, H.S. Mashriqui, and J.N. Day. 2001. Mississippi River

diversion into the Maurepas Swamp- water quality analysis (Attachment F). In: Lee Wilson &

Associates, Diversion Into the Maurepas Swamps- A Complex Project under the Coastal

Wetlands Planning, Protection, and Restoration Act. Report to EPA under Contract No. 68-06-

0067, WA #5-02.

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.

Effler, R.S., R. Goyer, and G.J. Lenhard. 2006. Baldcypress and water tupelo responses to insect

defoliation and nutrient augmentation in Maurepas Swamp, Louisiana, USA Forest Ecology and

Management 236(2-3):295-304.

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.

Forder, D.R. 1995. Timber harvesting, coppicing and artificial regeneration of a cypress muck

swamp. M.S. Thesis. Southeastern Louisiana University, Hammond, LA.

Greene, M. 1994. The interacting effects of allogenic and autogenic agents on selected swamp

and freshmarsh vegetation. M. S. Thesis. Southeastern Louisiana University,

Hammond, LA.

Hamilton, A. and G.P. Shaffer. 2001. Wetland Value Assessment (Attachment G). In: Lee

Wilson & Assoc., Diversion Into the Maurepas Swamps. A Complex Project under the Coastal

Wetlands Planning, Protection, and Restoration Act. Report to EPA under Contract No. 68-06-

0067, WA #5-02.

Hatton, R. S. 1981. Aspects of marsh accretion and geochemistry: Barataria Basin, Louisiana.

M.S. thesis. Louisiana State University, Baton Rouge, LA.

Hoeppner, S.S., G.P. Shaffer, and T.E. Perkins. 2007. Through droughts and hurricanes: The

survival and productivity of a coastal swamp in the Mississippi River Deltaic Plain. Forest

Ecology & Management.

Kozlowski, T.T. 1984. Plant responses to flooding of soil. BioScience 34:162-167.

Messina, M.G. and W.H. Conner (eds.). 1998. Southern Forested Wetlands: Ecology and

Management. Lewis publishers, New York, NY.

Myers R.S., G.P. Shaffer, and D.W. Llewellyn. 1995. Baldcypress (Taxodium distichum (L.)

Rich.) Restoration in southeast Louisiana: Relative effects of herbivory, flooding, competition,

and macronutrients. Wetlands 15:141-148.

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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.

Pezeshki, S.R. 1990. A comparative study of the response of Taxodium distichum and Nyssa

aquatica to soil anaerobiosis and salinity. Forest Ecology and Management 33/34:531-541.

Rybczyk, J., J.W. Day, and W. Conner. 2002. The impact of wastewater effluent on accretion

and decomposition in a subsiding forested wetland. Wetlands. 22(1): 18-32.

Shaffer, G.P., J.M. Willis, S. Hoeppner, A.C. Parsons, and M.W. Hester. 2001. Characterization

of ecosystem health of the Maurepas Swamp, Lake Pontchartrain Basin, Louisiana: feasibility

and projected benefits of a freshwater diversion. In: Lee Wilson & Associates, Diversion Into

the Maurepas Swamps- A Complex Project under the Coastal Wetlands Planning, Protection, and

Restoration Act. Report to EPA under Contract No. 68-06-0067, WA #5-02.

Shaffer, G.P., T.E. Perkins, S. Hoeppner, S. Howell, H. Benard, and A.C. Parsons. 2003.

Ecosystem Health of the Maurepas Swamp: Feasibility and Projected Benefits of a Freshwater

Diversion. Final Report for the Environmental Protection Agency. Region 6.

Shaffer, G.P., T.E. Perkins, D.A. Thomson, S. Howell, and S.S. Hoeppner. 2006. Ecology and

Restoration Potential of the Manchac Wetlands: Simulating a Diversion in the Maurepas

Swamps. Lake Pontchartrain Basin Research Program Highlight. No. 1, Southeastern Louisiana

University, Hammond, LA.

Shaffer, G., W.B. Wood, S.S. Hoeppner, T.E. Perkins, J. Zoller, and D. Kandalepas. 2008.

Degradation of Cypress-Tupelo Swamp to Marsh and Open Water in Southeastern Louisiana,

USA: An Irreversible Trajectory? Abstract Society of Wetlands Annual Conference,

Washington, DC.

Souther, R.F. and G.P. Shaffer. 2000. The Effects of Submergence and Light on Two Age

Classes of Baldcypress (Taxodium distichum [L.] Richard) Seedlings. Wetlands 20(1):697-706.

Thomson, D.A. 2000. The influence of hydrological alterations upon wetland hydrodynamics

and plant growth on the Manchac Landbridge, Southeastern Louisiana, USA. M.S. Thesis,

Southeastern Louisiana University, Hammond, LA.

U.S. Army Corps of Engineers. 1955. Survey of Amite River and Tributaries, Louisiana. New

Orleans District. New Orleans, LA.

U.S. Army Corps of Engineers. 2004a. Louisiana Coastal Area (LCA) Ecosystem Restoration

Study. Volume I: Main Report. New Orleans District. New Orleans, LA.

U.S. Army Corps of Engineers. 2004b. Section 1135 Preliminary Restoration Plan, Amite River

Diversion Spoil Bank Gapping, State of Louisiana, Congressional District 6. New Orleans

District, New Orleans, LA.

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Appendix 

 		 
 



931

REAL ESTATE PLAN

Amite River Diversion Canal Modification Feasibility Study

Livingston, Ascension and St John the Baptist Parishes, Louisiana

May 6, 2010

933

Real Estate Plan

Amite River Diversion Canal Modification Feasibility Study

Livingston, Ascension and St. John the Baptist Parishes, Louisiana

Table of Contents

PURPOSE: .................................................................................................................. 3

PROJECT LOCATION AND STUDY AREA: .............................................................. 3

PROJECT SPONSOR:................................................................................................ 6

GENERAL PROJECT DESCRIPTION:....................................................................... 6

NON-FEDERAL SPONSOR OWNED LER:..10

ESTATES: ................................................................................................................. 10

SPONSOR LAND ACQUISITION EXPERIENCE: .................................................... 14

REAL ESTATE ACQUISITION SCHEDULE:............................................................ 14

PUBLIC LAW 91- 646: .............................................................................................. 15

ACQUISITION COSTS:............................................................................................. 15

LANDOWNER ATTITUDE: ....................................................................................... 15

ENVIRONMENTAL ISSUES: .................................................................................... 15

EXISTING FEDERAL PROJECTS & STATE / FEDERAL LANDS: ......................... 15

TIMBER / MINERAL / ROW CROP ACTIVITY: ........................................................ 15

INDUCED FLOODING:.............................................................................................. 16

ZONING ORDINANCES:........................................................................................... 16

UTILITIES AND FACILITIES TO BE RELOCATED: ................................................ 16

NAVIGATION SERVITUDE:...................................................................................... 16

ACQUISITION PRIOR TO PPA:......17

Exhibit I: Cross Sections for Channel Easements for Alternative 33

Exhibit II: Non-Federal Sponsor Assessment of Land Acquisition Experience

Exhibit III: Chart of Accounts

Exhibit IV: Non-Standard Estate Approval Request

Exhibit V: Quality Control Plan Checklist

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REAL ESTATE PLAN

Amite River Diversion Canal Modification Feasibility Study

Livingston, and Ascension Parishes, Louisiana

Purpose:

The purpose of this Real Estate Plan is to determine the impact of the proposed

construction on the real estate located within the project limits. This Real Estate Plan

(REP) presents a preliminary plan for any acquisitions of lands, easements,

relocations and rights-of-way necessary for construction and implementation of the

project. Contact with landowners in the study area has been limited. This document is

for planning purposes only and is subject to change.

The project is intended to reverse the trend of degradation of the lands located in the

Western Maurepas Swamp. The introduction of freshwater from the diversion canal

onto and across this land will restore hydrologic connectivity and provide valuable

nutrients to the surrounding swamp. The increase in sediments will facilitate land

building and offset the effects of subsidence. The enhancement of the wet/dry cycles

will promote germination and promote survival of seedlings to enhance establishment

of new forest growth.

The goal of this project is to reverse the degradation trend within the western

Maurepas Swamp ecosystem so as to contribute toward achieving and sustaining a

coastal ecosystem tha can support and protect the environment, economy, and

culture of southern Louisiana and thus the Nation.

Project Location and Study Area:

The Louisiana Coastal Authority (LCA) study area, which includes the Louisiana

coastal area from Mississippi to Texas, is comprised of two wetland-dominated

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ecosystems, the Deltaic Plain of the Mississippi River and the closely linked Chenier

Plain, both of which are influenced by the Mississippi River. For planning purposes,

the LCA study area was divided into four subprovinces, with the Deltaic Plain

comprising Subprovinces 1, 2, and 3, and the Chenier Plain comprising Subprovince

4 as shown in Figure 1.1. The LCA-Amite River Diversion Channel (ARDC) study area

as shown in Figures 1.2 and 1.3 is located in LCA Subprovince 1 and is situated along

the ARDC in Ascension and Livingston parishes, in the vicinity of Head of Island,

Louisiana. The study area is bounded to the north by the old channel of the Amite

River, Old River, Chinquapin Canal and Bayou Chene Blanc; to the east by the Blind

River; to the south by the Petite Amite River and the New River Canal; and to the

west by the Sevario Canal, Ascension Parish flood protection levees, and the Laurel

Ridge Canal; and is located in the following sections:

Township 9 South, Range 4 East, Sections 9-16, 22-27, and 34-36;

Township 9 South, Range 5 East, Sections 7, 14-36;

Township 9 South, Range 6 East, Section 30 and 19;

Township 10 South, Range 4 East, Sections 1-3 and 10-12; and

Township 10 South, Range 5 East, Sections 2-11.

LCA Ecosystem Restoration Study,

2004

Figure 1.1

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Study Area Region

Figure 1.2

Study Area and Subunits

Figure 1.3

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For planning purposes the study area has been divided into nine separate hydrologic

subunits. Each subunit was developed based on hydrologic differences that exist

throughout the study area due to natural and manmade hydrologic boundaries as

shown in Figure 1.4. These boundaries include natural topography such as dredged

material berms and natural ridges, as well as manmade and natural waterways. The

tentatively selected plan is located in hydrologic subunit NE-2. This subunit has a

high degree of habitat degradation and has little to no hydrologic connectivity. The

subunit is surrounded by the Chinquapin Canal to the north, an abandoned railroad

embankment to the west, the ARDC to the south, and Little Bayou Chene Blanc and

Blind River to the east.

Project Sponsor:

The non-Federal sponsor is the Coastal Protection and Restoration Authority of

Louisiana (CPRA). However the Office of Coastal Protection and Restoration (OCPR)

is the implementing arm of CPRA, which has been given authority to acquire and hold

these lands. As the non-Federal Sponsor, CPRA through OCPR must provide all real

estate interests required for this proposed project construction, i.e., all lands,

easements, right of way relocations, and any other interests, including suitable borrow

and dredged or excavated material disposal areas (LERRDs). OCPR has indicated it

would provide all lands, water bodies, and/or water bottoms that are owned, claimed,

or controlled by the State of Louisiana. If it becomes necessary OCPR, having no

quick take authority of its own, will partner with another public agency, such as the

Pontchartrain Levee District (PLD), to acquire the lands needed for this project. The

NFS feels confident in being able to meet the public need requirements of the quick

take statutes of the State of Louisiana.

General Project Description:

In or around 1956 the Amite River Diversion Project was constructed to enhance

drainage and flood control by diverting water from the Amite River to Lake Maurepas.

The ARDC is a 10.6 mile long artificial channel that extends from the Amite River at

mile 25.3 to mile 4.8 of the Blind River in Ascension and Livingston parishes (see

Figure 1.2). The canal is roughly 80 meters wide. As part of this construction, spoil

was deposited on each side of the newly constructed channel for future use. Since the

early 1960s, camp sites and homes have been constructed on these spoil banks.

Over the years since its construction, the result of these developments and this flood

control project has been the loss of fresh water and nutrient flowing into, out of and

across the proposed project area. As shown in the photograph in Figure 1.5, the

hydrological restrictions of the project in the 1950s had the unintended consequence

of wetland destruction. Storm surge from hurricanes have accelerated the damage

because of salt-water intrusion. The transition from the swamp to an open water

marsh is occurring.

This Real Estate Plan has been prepared after study and review of seven (7) of the

original thirty-nine (39) alternatives presented by the Project Development Team

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(PDT). These alternatives underwent additional screening to determine the maximum

benefit for the sponsorships investments.

Figure 1.5 Degraded Swamp Area

Impacts on existing uses of the land and restrictions to the land in the future as a

result of the project have been discussed during our process. The Real Estate Plan

considers the characteristics of the lands found within the project area as well as the

impact of the Tentatively Selected Plan (TSP). It is anticipated the increased

hydrologic connectivity will provide nutrients and sediments to the impact areas and

enhance the restoration of the swamp and prevent further degradation of the area.

The final TSP should closely restore the natural wet/dry cycles in this area before the

construction of the spoil banks. The result should promote seedling germination and

promote survival to enhance establishment of new forest growth.

Figure 1.6 depicts the North East quadrant of the Study Area. This map shows the

location of the TSP, Alt 33. The scope of work outlined in Alt 33 is concentrated in

sections 23, 24, 25, 26 & 27.

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Figure 1.6 Quadrangle Map of the Project Area.

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Figure 1.7 -TSP / Alternative 33

Features of the TSP (Figure 1.7) include:

Three dredged material bank openings and three conveyance channels in

the north bank of the ARDC in NE-2 with the westernmost cut in the north

bank of the ARDC also extending through the railroad grade into NE-1 to

add connectivity between NE-1 and NE-2.

Dredged material (5.0 acres) from the bank openings and the conveyance

channel would be sidecast in alternating berms so sheet flow is not

reduced.

One additional cut would be in the railroad grade approximately one-half

mile north of the existing cut in NE-1/NE-2.

Vegetative plantings of bottomland hardwood / freshwater swamp tree

species on 5.0 acres of dredged material berms.

Vegetative plantings of freshwater swamp tree species within 438 acres of

the swamp floor.

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Implementation of this alternative would restore the hydrologic connectivity between

NE-1 and NE-2 with the ARDC thus reducing impoundment within the wetlands.

Alternative 33 would benefit approximately 1,602 acres of existing freshwater swamp,

recreate 144 acres of freshwater swamp from freshwater marsh, and create 5.0 acres

of bottomland hardwood habitat from dredged material placement.

All excavation to take place for the cuts through the dredged material berms as well

as the conveyance channels through the swamp would be based on four design

cross-sections (attached Exhibit I). These cross-sections were developed in an effort

to mimic natural, existing cuts within the study area, which have been determined to

be self-maintaining. The material dredged from the existing berms would be placed

along the swamp-side of the excavated cut as new bottomland hardwood habitat. All

material dredged during construction of the conveyance channels would be placed

along alternating portions of the channels to allow sufficient sheet flow to be conveyed

from the swamp.

Non-Federal Owned LER:

The Non-Federal sponsor does not own any lands in the project right of way.

Estates:

The anticipated number of private property owners impacted by this project is one (1),

Blind River Properties, represented by Mr. Glen Martin. Blind River Properties owns

approximately 32,000 acres; a significant portion of this land is located within the

study area and the ownership encompasses all of the project area. See Figure 1.8.

No servitudes and rights of ways for pipelines or utilities are located in the project

area.

It is Corps of Engineers policy to acquire fee simple title for ecosystem restoration

projects. Two reasons for such requirement is to reduce the risk that incompatible

uses on project land will occur after project construction, and to ensure that ownership

rights vested in the project are clear and enforceable (ER 1105-2-100, Appendix F,

Amendment # 2, F-20b(2)(a). However, regulations also indicate that a lesser

interest, such as, a specific type of permanent easement, may be appropriate

depending upon the operational requirements of the project and other circumstances

relevant to project implementation, including landowner preference (EP 1165-2-502,

17b). Circumstances wherein the acquisition of interests less than fee may be

appropriate is where only select and easily identifiable and narrow affirmative rights

are required for successful implementation of the project (ER 1105-2-100, Appendix

F, Amendment # 2, F-20b(2)(b)i.)

It is the opinion of the Non-Federal Sponsor and the District that construction of this

project can be accomplished through the acquisition of easements rather than fee.

We propose acquisition of the following estates: a Channel or Channel Improvement

Easement over 23.6 acres of canal banks along the ARDC and existing waterways; a

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Wetland Creation and Restoration Easement over 438 acres to allow for vegetative

plantings on existing degraded swamplands and wetlands; and a Flowage and

Deposition Easement over 1,161+ acres of swamplands which will be further

inundated by the flow of water from the channel cuts. However, it should be noted

that this is a planning document and the necessary estates are subject to change

dependant upon project needs.

It is the opinion of the project delivery team that the estates proposed herein provide

sufficient rights to the Government to construct the project and also protect the

interests of the Government by prohibiting use of the surface for mineral exploration

or construction of improvements. In addition, because the project area is a wetland,

the project features are further protected through the police powers of the Federal

Government through Section 404 of the Clean Water Act which require a permit from

the Corps of Engineers for any activity that could negatively impact a wetland. Lastly,

due to the topography of the project site and its limited access, it is highly unlikely that

the landowner would propose development.

The non-standard estates were presented in the Louisiana Coastal Area  Louisiana,

Ecosystem Restoration Study, dated November 2004. Exhibit IV includes a

memorandum requesting approval of acquisition of interests less than fee as well as

approval of these non standard estates in accordance with SOP established by MVD

in December 2009.

THE NON-STANDARD ESTATES PRESENTED IN THIS REP ARE NOT

APPROVED AS PART OF THIS REAL ESTATE PLAN AND FURTHER REVIEW,

REVISION, AND APPROVAL OF SUCH ESTATES IS REQUIRED.

Figure 1.8  Blind River Properties

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Channel or Channel Improvement Easement (standard estate)

A perpetual and assignable right and easement to construct, operate, and

maintain channel improvement works on, over and across (the land described

in Schedule A) (Tracts Nos. _____, _____ and _____) for the purposes as

authorized by the Act of Congress approved_______________, including

he right to clear, cut, fell, remove and dispose of any and all timber, trees,

underbrush, buildings, improvements and/or other obstructions therefrom; to

excavate: dredge, cut away, and remove any or all of said land and to place

thereon dredge or spoil material; and for such other purposes as may be

required in connection with said work of improvement; reserving, however, to

the owners, their heirs and assigns, all such rights and privileges as may be

used without interfering with or abridging the rights and easement hereby

acquired; subject, however, to existing easements far public roads and

highways, public utilities, railroads and pipelines.

Wetland Creation And Restoration Easement (non-standard estate):

(based on the standard Perpetual Beach Nourishment Easement and other

standard estates)

A perpetual and assignable easement and right-of-way in, on, over and across

(the land described in Schedule A) (Tract No. -) to construct, operate, maintain,

patrol, repair, renourish, and replace wetlands and associated coastal habitats,

including the right to borrow and/or deposit fill; to accomplish any alterations of

contours on said land; to plant vegetation on said land; to excavate, dredge,

cut away, and remove any or all of said land and to place thereon dredge or

spoil material; to construct dikes and to install, alter, relocate, repair or plug

cuts in the banks of dikes; to construct, operate and maintain pipelines for the

purpose of dredge or spoil material transport and deposition; to move, store

and remove equipment and supplies; to plug, fill or alter pipeline canals located

within the limits of the easement; to trim, cut, fell and remove therefrom all

trees, underbrush, obstructions, and any other vegetation, structures, or

obstacles within the limits of the easement (excepting the structures now

existing on the land, described as _________), provided that no other

structures shall be constructed or maintained on the land except as may be

approved in writing by the representative of the United States in charge of the

project, that no excavation shall be conducted and no landfill placed on the

land without such approval as to the location and method of excavation and/or

placement of landfill, [that no vehicles shall be operated within the limits of the

easement without such approval, except as may be required to operate and

maintain the easement,] and that no trimming, cutting, felling or removal of

trees, underbrush, and any other vegetation shall be conducted without such

approval; the above estate is taken subject to existing easements for public

roads and highways, public utilities, railroads and pipelines; reserving,

however, to the grantor(s), (his) (her) (its) (their) (heirs,) successors and

assigns, all such rights and privileges as may be used without interfering with

or abridging the rights and easement hereby acquired; and expressly excepting

946
13

and excluding all oil, gas and other minerals occurring naturally in liquid or

gaseous form, in and under said land and all appurtenant rights for the

exploration, development, production and removal of said oil, gas and other

minerals occurring naturally in liquid or gaseous form, but without the right to

enter upon or over the surface of said land for the purpose of exploration,

development, production and removal therefrom of said oil, gas and other

minerals occurring naturally in liquid or gaseous form.

Flowage and Deposition Easement *(non-standard estate):

The perpetual right, power, privilege and easement occasionally to overflow the

land described in Schedule A (Tracts Nos. ____, ____) and in connection with

the operation and maintenance of the project, including the continuing right to

clear and remove and brush, debris and natural obstructions which, in the

opinion of the representative of the United States in charge of the project,

may be detrimental to the project; and to deposit dredge material or sediment

on the land, together with all right, title and interest in and to the structures

and improvements now situate on the land, excepting _________________

(here identify those structures not designed for human habitation which the

District Engineer determines may remain on the land ); provided that no

structures for human habitation shall be constructed or maintained on the land,

that no other structures shall be constructed or maintained on the land except

as may be approved in writing by the representative of the United States in

charge of the project, that no vehicles shall be operated within the limits of the

easement without such approval, except as may be required to operate and

maintain the easement, that no trimming, cutting, felling or removal of trees,

underbrush, and any other vegetation shall be conducted without such

approval, and that no excavation shall be conducted and no landfill placed on

the land without such approval as to the location and method of excavation

and/or placement of landfill; the above estate is taken subject to existing

easements for public roads and highways, public utilities, railroads and

pipelines; reserving, however, to the landowners, their heirs and assigns, all

such rights and privileges as may be used and enjoyed without interfering with

the use of the project for the purposes authorized by Congress or abridging the

rights and easement hereby acquired; provided further that any use of the land

shall be subject to Federal and State laws with respect to pollution; and

expressly, excepting and excluding all oil, gas and other minerals occurring

naturally in liquid or gaseous form, in and under said land and all appurtenant

rights for the exploration, development, production and removal of said oil, gas

and other minerals occurring naturally in liquid or gaseous form, but without

the right to enter upon or over the surface of said land for the purpose of

exploration, development, production and removal therefrom of said oil, gas

and other minerals occurring naturally in liquid or gaseous form.

*

Because nutrients will flow from the Amite River Diversion Canal into the benefits area via the channel cuts, a

Flowage and Deposition Easement is suggested. However, no emergent lands will be created as a result of

direct deposition of sediment.

947
14

Sponsor Land Acquisition Experience:

The Non-Federal sponsor for this project is the Coastal Protection and

Restoration Authority of Louisiana (CPRA), through the Office of Coastal Protection

and Restoration. As the non-federal sponsor, CPRA must provide all real estate

interests required for the project, i.e., all lands, easements, rights-of-way, relocations,

and any other interest, including suitable borrow and dredged or excavated material

disposal areas (LERRDs).

The Non-Federal Sponsor is assessed to be fully capable to perform all

acquisition activities associated with this project. The Sponsor has the capability to

acquire and hold real estate as well as the ability to contract for real estate services to

supplement its staff in order to meet project schedules. However, it must be

recognized herein that CPRA is the non-federal sponsor for all New Orleans District

coastal restoration projects and all hurricane risk reduction projects. Therefore, if all

LCA projects and several hurricane risk reduction projects are authorized for

construction under concurrent schedules, there is a possibility that CPRA may not be

able to accomplish LER acquisition due to the massive amount of work required for

such an undertaking. If that were the case, it is possible that CPRA may request that

the Federal Government accomplish acquisition of LER on their behalf.

The Assessment of the Non-Federal Sponsors Real Estate Acquisition

Capabilities is attached as Exhibit II.

Real Estate Acquisition Schedule:

Acquisition will not begin until after the Project Partnering Agreement (PPA) is signed.

Based on current schedule information, the land rights acquisitions would need to be

started February 1, 2012 to meet the construction date of August 1, 2012. Based on

acquisition of right of way from one landowner, estimated task durations are:

Task Task Duration

Obtain title information 60 days

Obtain mapping information 60 days

Obtain appraisals 60 days

Negotiate & issue right-of-entry 90 days

These time frames assume amicable acquisitions, if condemnation proceedings are

necessary, 12 months will be added to the schedule.

948
15

Public Law 91- 646:

All acquisitions of private property for this project will be done in accordance with the

provisions of Public Law 91-646, as amended. All areas impacted by construction are

vacant; the project will not displace any persons, businesses or farms.

Acquisition Costs:

The estimated total Real Estate costs are $136,000.00. Real Estate costs have been

outlined in the Chart of Accounts found in Exhibit III.

Landowner Attitude:

Owner contact, to date, has been limited. However, feedback from the private

landowner, Mr. Glen Martin, has been positive. Mr. Glen Martin representing Blind

River Properties owns the land required for this TSP. The landowner appears to be in

favor of the project, given the direct benefits to his property.

Environmental Issues:

A Phase I Environmental Site Assessment (ESA) of the LCA-ARDC study area was

conducted in accordance with USACE Regulation ER 1165-2-132, Water Resources

Policies and Authorities for HTRW Guidance for Civil Works Projects, 26 June 1992

and the American Society for Testing and Materials (ASTM) Standard E 2247-08

Standard Practice for Environmental Site Assessments: Phase I Environmental Site

Assessment Process for Forestland or Rural Property in order to identify recognized

environmental conditions (REC) located on, or in the vicinity of, the LCA-ARDC study

area.

A review of various Federal and state databases indicates that none of the potential

recognized environmental conditions (REC) sites found in the area would be likely to

expose the public or construction workers to HTRW or to adversely affect the project.

Existing Federal Projects & State/Federal Owned Lands:

While we know the construction of the Amite River Diversion Canal was a public

project, done in conjunction with the USACE and Livingston Parish, we have been

unable to confirm easements or agreements to establish ownership or restrictions of

the spoil banks. Additional research will be required when this project advances. At a

recent meeting with the landowner, he stated the Diversion Project was built as part of

the drainage servitude and the spoil, and the water bottoms, belong to Blind River

Properties. This will be verified when the project progresses and prior to any

agreements being executed.

Timber / Mineral / Row Crop Activity:

A timber survey and appraisal was conducted in 1994 by

a professional forestry consultants for the 32,000 acres owned by Blind River

949
16

Properties. The consultants found that there were no areas of cypress and

tupelo in the swamps with trees of sufficient size and volume to be

considered merchantable. Merchantable size timber (red oak, sweet gum, and

ash) was found only on the ridges, including those in the study area.

However, marketability was considered doubtful because of inaccessibility.

There is no timber harvesting in the project area.

The western Maurepas Swamp has undergone significant oil and gas exploration

activity, particularly in the early to mid-20th century. However, most oil and gas

exploration and production activities in the region have occurred southwest of the

study area. Data from the LDNR Strategic Online Natural Resources Information

System (SONRIS) (http://sonris-www.dnr.state.la.us/www_root/sonris_portal_1.htm)

indicate that oil and gas production activities within the study area have been

relatively light and occurred primarily in the late 20th century. It is our understanding

that the owner of the minerals is the same entity which owns the surface rights. The

easements to be acquired by the Government prohibit constructing improvements

without the written permission of the United States which in essence could prohibit

use of the surface for the exploration of minerals over the encumbered areas. The

ownership impacted by this project is approximately 32,000 acres; the project areas

are surrounded by the remaining unencumbered lands. The owner has access points

throughout the perimeter of the project area to conduct directional drilling for oil or gas

in the event that those minerals are present in the property. Therefore, the acquisition

of the proposed easements does not impose a mineral taking.

There is no evidence of row crop activity in the project area.

Induced Flooding:

The construction of this project will allow water from the Amite River Diversion Canal

to flow into, onto and across private land discharging into the adjacent swamp. As the

water dissipates, sediments and nutrients will be deposited to assist in swamp

restoration. Where water will flow across private lands, OCPR will acquire Flowage

Easements.

Zoning Ordinances:

No zoning ordinances will be enacted in lieu of or to facilitate acquisition in connection

with this project.

Utilities and Facilities to be Relocated:

There are no utility or facility relocations required in connection with this project.

Navigation Servitude:

Derived from the Commerce Clause of the U.S. Constitution, article 1, section 8,

clause 3, the navigation servitude is the dominant right of the United States to use,

control and regulate navigable waters and submerged lands. The applicability of the

950
17

navigation servitude depends on both legal and factual determinations. If the legal

determination supports assertion of the navigation servitude, then the second step is

to determine the geographical area over which the servitude can be asserted. In tidal

areas, the servitude extends to all lands below the mean high water mark, whereas in

non-tidal areas, the servitude extends to all lands within the bed and banks of a

navigable stream that lie below the ordinary high water mark.

There are no lands being acquired for this project which would fall in this

classification.

Acquisition Prior to PPA:

The non-federal sponsor is the author of this REP and is fully aware of the risks

associated with acquisition of real estate rights prior to signing a Project Partnership

Agreement.

951
952
953

955
956
957
958
959

961

963
964
965

CEMVN-RE-E

REAL ESTATE DIVISION

Chart of Accounts January 28, 2010

AMOUNT CONTINGENCY PROJECT

COST

ROUNDED $136,000

TOTAL PROJECT COSTS 112,900 23,360 136,260

01 LANDS AND DAMAGES CONTINGENCYPROJECT 112,900 23,360 136,260

COST

01B ACQUISITIONS

01B10 BY GOVERNMENT 0 0 0

01B20 BY NON FEDERAL SPONSOR (NFS) 9,500 0 9,500

01B30 BY GOVT ON BEHALF OF NFS 0 0 0

01B40 REVIEW OF NFS 5,000 0 5,000

01C CONDEMNATIONS

01C10 BY GOVERNMENT 0 0 0

01C20 BY NFS 0 0 0

01C30 BY GOVT ON BEHALF OF NFS 0 0 0

01C40 REVIEW OF NFS 0 0 0

01E APPRAISAL

01E10 BY GOVT (IN HOUSE) 0 0 0

01E20 BY GOVT (CONTRACT) 0 0 0

01E30 BY NFS 3,000 0 3,000

01E40 BY GOVT ON BEHALF OF NFS 0 0 0

01E50 REVIEW OF NFS 2,000 0 2,000

01F PL 91-646 ASSISTANCE

01F10 BY GOVERNMENT 0 0 0

01F20 BY NFS 0 00

01F30 BY GOVT ON BEHALF OF NFS 0 0 0

01F40 REVIEW OF NFS 0 0 0

01G TEMPORARY PERMITS/LICENSES/RIGHTS-OF-ENTRY

01G10 BY GOVERNMENT 0 0 0

01G20 BY NFS 0 0 0

01G30 BY GOVT ON BEHALF OF NFS 0 0 0

01G40 REVIEW OF NFS 0 0 0

01G50 OTHER 0 0 0

01G60 DAMAGE CLAIMS 0 0 0

01N00 FACILITY/UTILITY RELOCATIONS

01R REAL ESTATE PAYMENTS

01R1 LAND PAYMENTS

01R1A BY GOVERNMENT 0 0 0

01R1B BY NFS 92,900 23,230 116,130

01R1C BY GOVT ON BEHALF OF NFS 0 0 0

01R1D REVIEW OF NFS 0 0 0

01R2

01R2A BY GOVERNMENT 0 0 0

01R2B BY NFS 0 0 0

01R2C BY GOVT ON BEHALF OF NFS 0 0 0

01R2D REVIEW OF NFS 0 0 0

01R3

01R3A BY GOVERNMENT 0 0 0

01R3B BY NFS 0 0 0

01R3C BY GOVT ON BEHALF OF NFS 0 0 0

01R3D REVIEW OF NFS 0 0 0

01R9 OTHER 0 00

01T LERRD CREDITING

01T20 ADMINISTRATIVE COSTS 500 130 630

PL 91-646 ASSISTANCE PAYMENTS

DAMAGE PAYMENTS

Page 1

967

969

971
972
973
974
975

977

979

981

983

985

Quality Control Checklist

Request to Deviated from Guidance as to Appropriate

Interest to Acquire

and/or

Request for Approval of Use of Non-standard Estate

ER 405-1-12, paragraphs 12-9 and 12-10

PROJECT: LCA AMITE RIVER DIVERSION CANAL MODIFICATION

Title and date of Decision Document which contains the REP requesting approval

of estate deviation or NSE approval____LCA Amite River Diversion Canal Modification

Feasibility Study_____________________________________________________

Subject line and date of memorandum requesting approval of estate deviation or NSE

approval ____N/A  Requested as an exhibit in the Real Estate Plan_________________

1. Does the proposed estate, whether standard or non-standard; provide sufficient interest

for the construction, operation, and maintenance of the project? ____YES___________

2. Coordination has been made with the following and they concur with use of the

proposed estate:

Project Management _____X_____ E&C __X_____

Operations _______X_________ Office of Counsel ____X_____

Coordination was made with the following other functional groups. __Environmental__

3. A statement of legal sufficiency from OC is attached to the REP or memo requesting

approval by HQ ____Yes______

4. Is the cost to acquire the proposed estate more than cost of acquiring a standard interest

with a standard estate? ___No____ Is this discussed in the request? ____YES______

5. Did the Non-Federal Sponsor (NFS) propose the deviation from appropriate interest or

use of a NSE? __No__

If so, why? _____________________________________________________________

If not, was the deviation or NSE coordinated with the NFS? ___Yes_____________

6. Can the non-standard estate be approved by the district Chief of RE? ____No_____

987
If so it must :

Serve the intended project purpose __________________

Substantially conform with and not materially deviate form the corresponding standard

estate __________

Does not increase the costs nor potential liability of the Government? _____________

7. Does the NSE conform to format of standard estates _____Yes_____?

8. Does the request for approval which goes through MVD to HQ, contain a detailed

explanation of and justification for the deviation as to interest to be acquired? _Yes_

9. Does the request contain a detailed explanation of each non-standard clause in the

estate? _Yes__ The request must detail the need for the language in relation to project

requirements. Each non-standard right to be acquired, restriction/prohibition placed on

fee owners interest and /or reservation to the fee owner must be fully discussed. Is the

acquisition or reservation of mineral rights held by the fee owner or outstanding 3rd party

mineral rights fully discussed in relation to the estate language and project requirements?

____Yes_____

If there are clauses found in the corresponding standard estate which have been deleted,

is there an explanation of the deletion? ____N/A____

10. Has the district deviated as to the appropriate interest on similar projects in the past?

___Yes___ If so, which project(s)? __The Wetland Creation and Restoration Easement is

proposed for approval for other LCA projects.

11. Has the proposed NSE been previously approved by HQ for use for a project in your

district? ____No____. If so, which project(s)? ____

Provide a copy of the previous approval.

A copy of this Checklist is attached to the REP or memorandum requesting a deviation as

to interest to be acquired or approval of a NSE. ___Yes___

___N/A________________________ Date: _____________________________

Realty Specialist or Appraiser

July 28, 2010

___________________________ Date: _____________________________

Branch or Section Chief

988
989

991
992
993
994
995
996
Appendix K

ECONOMICS AND BENEFITS

997

TOC-i

Appendix K

TABLE OF CONTENTS

Section Page

SECTION I

Wetland Value Assessment Project Information Sheet, December 2009 .............................. 1

Project Name ................................................................................................................... 1

Project Type ................................................................................................................... 1

Sponsoring Agency........................................................................................................... 1

Project Area ................................................................................................................... 1

Problem ................................................................................................................... 1

Goal ................................................................................................................... 1

Objectives ................................................................................................................... 1

Project Features................................................................................................................. 2

Low Sea Level Rise Scenario Assumptions .............................................................................. 3

Fresh Marsh ................................................................................................................... 3

Variable 1: Stand Structure.................................................................................. 3

Variable 2: Stand Maturity................................................................................... 4

Variable 3: Water Regime ................................................................................... 6

Variable 4: Mean High Salinity During the Growing Season ............................. 7

10 Years to Marsh............................................................................................................. 8

Variable 1: Stand Structure.................................................................................. 8

Variable 2: Stand Maturity................................................................................. 10

Variable 3: Water Regime ................................................................................. 11

Variable 4: Mean High Salinity During the Growing Season ........................... 12

20 - 30 Years to Marsh.................................................................................................... 13

Variable 1: Stand Structure................................................................................ 13

Variable 2: Stand Maturity................................................................................. 15

Variable 3: Water Regime ................................................................................. 16

Variable 4: Mean High Salinity During the Growing Season ........................... 17

30 - 50 Years to Marsh.................................................................................................... 18

Variable 1: Stand Structure................................................................................ 18

Variable 2: Stand Maturity................................................................................. 20

Variable 3: Water Regime ................................................................................. 21

Variable 4: Mean High Salinity During the Growing Season ........................... 22

Secondary Impact Areas .......................................................................................................... 23

999
TOC-ii

Appendix K

TABLE OF CONTENTS (cont’d)

Section Page

Fresh Marsh ........................................................................................................ 23

Variable 1: Stand Structure................................................................................ 23

Variable 2: Stand Maturity................................................................................. 25

Variable 3: Water Regime ................................................................................. 26

Variable 4: Mean High Salinity During the Growth Season ............................. 27

10 Years to Marsh........................................................................................................... 28

Variable 1: Stand Structure................................................................................ 28

Variable 2: Stand Maturity................................................................................. 30

Variable 3: Water Regime ................................................................................. 32

Variable 4: Mean High Salinity During the Growing Season ........................... 32

20 - 30 Years to Marsh.................................................................................................... 34

Variable 1: Stand Structure................................................................................ 35

Variable 2: Stand Maturity................................................................................. 35

Variable 3: Water Regime ................................................................................. 37

Variable 4: Mean High Salinity During the Growing Season ........................... 38

30 - 50 Years to Marsh.................................................................................................... 39

Variable 1: Stand Structure................................................................................ 39

Variable 2: Stand Maturity................................................................................. 40

Variable 3: Water Regime ................................................................................. 42

Variable 4: Mean High Salinity During the Growing Season ........................... 43

Table --Low RSLR ................................................................................................................. 45

Alternative 33................................................................................................................. 45

Alternative 39................................................................................................................. 45

Intermediate RSLR ......................................................................................................... 45

Alternative 33 ................................................................................................................. 45

Alternative 39 ................................................................................................................. 46

High RSLR ................................................................................................................. 46

Alternative 33 ................................................................................................................. 46

Alternative 39 ................................................................................................................. 46

WVA Data ................................................................................................................. 47

Figure 1. Primary and Secondary Impact Areas for Wetland Value

Assessment Future With Project Conditions .......................................... 49

1000
TOC-iii

Appendix K

TABLE OF CONTENTS (cont’d)

Section Page

Figure 2. Wetland Value Assessment Areas for Alternative 33 -

Cut A and Conveyance Channel............................................................. 50

Figure 3. Wetland Value Assessment Areas for Alternative 33 -

Cut B and Conveyance Channel ............................................................. 51

Figure 4. Wetland Value Assessment Areas for Alternative 33 -

Cut C and Conveyance Channel ............................................................. 52

Figure 5. Wetland Value Assessment Areas for Alternative 34 ................................... 53

Figure 6. Wetland Value Assessment Areas for Alternative 35 .................................... 54

Table -- Summary of acreages for each alternative by habitat type used in the WVA

benefits analysis................................................................................................. 55

WVA Model Certification - Comments and Responses ........................................................ 57

SECTION 2

Louisiana Coastal Area Amite River Diversion Canal Modification

Integrated Feasibility Study and Environmental Impact Statement --

IWR CE/ICA Analysis.................................................................................................... 1

Cost Effective and Incremental Cost Analysis ......................................................................... 1

Introduction ................................................................................................................... 1

Amite River Diversion Canal Modification...................................................................... 1

IWR Results ................................................................................................................... 2

Table 1 Cost and Benefit Breakdown for Final Array of Alternatives .............................. 2

Table 2 IWR Results.......................................................................................................... 3

Figure 1 Cost-Effective Frontier ......................................................................................... 3

Figure 2 Benefit vs. Cost Plot ............................................................................................. 4

Background of CE/ICA Analysis............................................................................................... 5

Table 1 Step 5 - Cost Effective Solutions.......................................................................... 5

Table 2 Step 6 - Average Costs.......................................................................................... 6

Table 3 Step 7A - First Recalculation................................................................................ 6

Table 4 Step 7B - Second Recalculation............................................................................ 6

Table 5 Step 7C - Summary of Results.............................................................................. 7

Table 6 Step 7D - Solutions with Lowest Average Costs for Additional Output.............. 7

Table 7 Step 8A - Incremental Costs ................................................................................. 7

Table 8 Step 8B - Solutions with Lowest Average Costs for Additional Output

Table 9 Step 9 - Justification.............................................................................................. 9

Figure 1 Step 5 - Cost Effective Solutions.......................................................................... 5

Figure 2 Step 8 - Incremental Cost...................................................................................... 8

1001
TOC-iv

1002
SECTION 1

1003

Wetland Value Assessment Project Information Sheet

December 2009

Project Name: Louisiana Coastal Area Amite River Diversion Canal (LCA ARDC)

Modification project

Project Type(s): Swamp restoration, hydrologic restoration, and vegetative planting

Sponsoring Agency: U.S. Army Corps of Engineers (USACE) and Louisiana

Department of Natural Resources

Preparer of Wetland Value Assessment (WVA) information sheet: Karen Soileau

Information found in this project information sheet was obtained primarily from the Draft

Feasibility Report appendix (CPE 2005 and 2007).

Project Area: The project area is situated along the Amite River Diversion Canal

(ARDC) in Ascension and Livingston Parishes, in the vicinity of Head of Island,

Louisiana. The project area is focused around the impaired bald cypress-tupelo swamp

stands adjacent to the ARDC, extending northward and southward of the canal in the

western portion of the Maurepas Swamp, located within the Pontchartrain Basin.

Project area boundaries were developed and delineated based on hydrologic features of

the area suspected of being influenced by the LCA ARDC Modification project. For

planning purposes, the project area was further divided into nine sub-areas. Those subareas are defined by topographic high points (e.g., dredged material berms, relict railroad

grade, road embankments) or natural and artificial channels (e.g., rivers, canals) that

would serve to impede or intercept hydrologic flows.

Problem: The project area includes the ARDC, a 10.6-mile-long flood control channel

between the Amite and Blind Rivers. Dredged material excavated during channel

construction was deposited in dredged material berms on either side of the canal. The

construction of the ARDC and its associated dredged material berms, and the resulting

impoundment, channelization, surge-related saltwater intrusion, and the loss of

freshwater, sediments, and nutrients from the Amite River have all caused significant

adverse impacts to the area, resulting in poor swamp health and ecosystem degradation in

the western Maurepas Swamp.

Goal: The goal of the LCA ARDC Modification project is to reverse the trend of

degradation in the western portion of the Maurepas Swamp, so as to contribute toward

achieving and sustaining a coastal ecosystem that can support and protect the

environment, economy, and culture of southern Louisiana and thus the Nation.

Objectives:

1005
2

• Increase hydrologic connectivity between the degraded swamp and

bottomland hardwood habitats within the study area and the ARDC by

increasing the exchange of freshwater, sediments, and nutrients over the 50-

year period of analysis.

• Reduce habitat conversion of swamp to open water within the study area over

the 50-year period of analysis.

• Facilitate natural hydrologic cycle within the study area over the 50-year

period of analysis by reducing impoundment in degraded swamp and

bottomland hardwood habitats adjacent to the ARDC to improve tree

productivity and seedling germination.

• Improve fish and wildlife habitat within the study area over the 50-year period

of analysis.

Project Features:

1. Freshwater Reintroduction – Restoring processes that input freshwater, nutrients,

and sediments are essential for establishing sustainable coastal swamp systems.

The implementation of freshwater reintroduction measures that establish

hydrologic connectivity between study area waterbodies and the adjacent swamp

habitat could nourish existing swamp habitat to increase productivity and restore

areas that have converted to freshwater marsh or open water, reintroduce

sediments and nutrients throughout the ecosystem, and allow aquatic organisms

access to previously unavailable habitats. The benefits that such reintroductions

produce increase over time and continue as long as the reintroduction is operated

and maintained. Additionally, freshwater reintroductions can be adaptively

managed to respond to environmental changes and optimize benefits.

2. Habitat Restoration – The majority of the Maurepas Swamp is stressed as a result

of hydrologic alteration and seems to be on a trajectory of slow degradation

leading to a gradual conversion to marsh and open water (Hoeppner et al., 2007).

Without restoration, the factors and processes that are contributing to stress and

deterioration of the swamps in the vicinity of the ARDC would continue and

would result in loss of the swamp, with succession to open water. The wetland

loss rates for the Coast 2050 Amite/Blind Rivers mapping unit (which contains

the study area) for 1974-90 were estimated by the Corps to be 0.83 percent per

year for swamp habitat, and 0.02 percent per year for fresh marsh. Based on these

rates, approximately 50 percent of swamp and 1.2 percent of fresh marsh would

be lost within 60 years (Coastal Wetlands Planning, Protection, and Restoration

Act [CWPPRA] Task Force, 2002). Additionally, the Corps determined that,

based on the low tree density, degraded condition, and expectation for mortality,

the majority of swamp habitat within the study area would degrade to less than 33

percent canopy cover within 20 years (USACE, 2004). Under the continued

influence of these conditions, tree mortality would continue to increase and tree

density would continue to decline, until most swamp habitat in the vicinity of the

ARDC converts to fresh marsh. Monitoring studies conducted for the CWPPRA

Priority Project List 12 (PPL 12) proposal indicated that conversion of bald

cypress-tupelo swamp to fresh marsh is already occurring in the study area,

1006
3

particularly north of the ARDC in subunit NE-2 (CWPPRA Task Force, 2002).

Additionally, the monitoring results indicate that many areas of fresh marsh in the

greater southern Maurepas Swamp have converted to fragile spikerush flotant,

which is particularly susceptible to nutrient starvation and fragmentation.

Consequently, it is expected that the vast majority of swamp habitat adjacent to

the ARDC would convert to open water rather than stable marsh habitat without

implementation of the proposed project.

LOW SEA LEVEL RISE SCENARIO ASSUMPTIONS

Primary Impact Areas

• Fresh Marsh – The Swamp Model was chosen for this area over the Fresh Marsh

Model, even though there is less than a 33 percent canopy cover, because the area

provides functions and values more closely associated with a swamp than a fresh

marsh.

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. It was the consensus of the

group that there is less than 33 percent overstory

closure. [Class 1]

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, the

area is expected to remain a Class 1.

Future With Project

Target Year 1 –

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 1.

Future With Project

Target Year 10 –

1007
4

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. However, cypress trees planted at TY1

would be 11 years old. In Louisiana, the height of

cypress at 10 years of age is, on average, 17 feet

(U.S. Department of Agriculture [USDA] 1980).

Therefore, because there were no tree species within

the midstory at TY 0 and because planted cypress

trees would not be old enough yet to be considered

a component of the overstory, we anticipate the

stand structure would remain a Class 1.

Future With Project

Target Year 25 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

and would, therefore, be considered a component of

the overstory. Accordingly, we anticipate an

overstory closure of 50 -75 percent with a midstory

or herbaceous cover greater than 33 percent. [Class

4]

Future With Project

Target Year 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should continue to improve habitat

conditions within the area. Accordingly, we

anticipate an overstory closure of greater than or

equal to 75 percent with either a midstory cover or

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

1008
5

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His diameter at

breast height (dbh) estimate, for all tree species

combined, was between 6.5 and 8.25 inches, as

compared to our average of 6.3 inches determined

during our Wetland Value Assessment (WVA) data

collection field assessment. Although our estimate

is on the lower end of the range determined by Mr.

Wood, because the subject area represents some of

the more degraded habitat we feel that this estimate

is representative of existing habitat conditions.

Basal area was estimated based on information

gathered during the aforementioned field visit and

data collected by Southeast Louisiana University

over the past 10 years.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated utilizing data collected by Southeast

Louisiana University and percent composition of

canopy trees was estimated based on best

professional judgment. Within the PPL 12 WVA it

was assumed that 50 percent of the tupelo et al

would die over 20 years, but that actual mortality of

cypress would be minimal. Over the 50 year project

life, we assume that 75 percent of the tupelo et al

would die with minimal cypress mortality. In

addition, we assume that minimal regeneration

would occur over 50 years based on the degraded

habitat conditions and lack of tree species at TY 0

in the understory. Subsequently, under the future

1009
6

without project scenario, basal areas decreased from

time year 0 to 50.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the primary impact areas would receive

the most benefits from freshwater flows, nutrients,

and sediments; thus, those areas should see the

greatest increase in growth. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 167% of current growth in the

primary impact areas, which is the same assumption

used in the PPL 12 WVA. Percent composition of

cypress trees in the canopy was increased over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 –

At present the Maurepas Swamp within this portion

of the project area are permanently flooded and

have no flow/exchange.

Future Without Project

1010
7

Target Years 1 – 50 –

Continued degradation of the area is expected under

the future without project scenario and we

anticipate the project area to remain permanently

flooded with no flow/exchange.

Future With Project

Target Years 1 – 50 –

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

Subsidence is expected to continue within the

project area over time under the future without

project scenario. We, therefore, assume that the

ability for saltwater to intrude further and/or more

frequently into the project area swamps would

likewise increase. Because the subject area is

impounded with no flow/exchange we expect the

1011
8

salinity to increase over time. Thus, we assumed

that mean high salinity during the growing season to

increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 ppt from TY 1-10).

Because of the anticipated increase in sea level rise

over time, however, we assume an increase in mean

high salinities of 1.0 and 1.2 ppt for TY 25 and 50,

respectively.

• 10 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

35 percent with an approximate midstory cover of

17 percent. [Class 2]

Future Without Project

Target Year 1 –

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 2.

Future Without Project

Target Years 10 – 50 –

1012
9

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, we

downgraded the variable to a Class 1.

Future With Project

Target Year 1 –

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 2.

Future With Project

Target Year 10 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. While the majority cypress trees in the

project area (planted at TY1) would be 11 years old,

and would not be old enough yet to be considered a

component of the overstory, other midstory tree

species present at TY 0 (i.e., red maple, green ash,

and water tupelo) would become a component of

the overstory at TY 10. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. Thus, we anticipate an

overstory canopy closure between 33 and 50

percent and greater than a 33 percent midstory or

herbaceous cover. [Class 3]

Future With Project

Target Years 25 – 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

1013
10

and would, therefore, be considered a component of

the overstory. Because construction of the gaps is

designed to allow for drainage of the area during

ARDC low flow events, seedling germination,

establishment, and survival is expected to increase.

Thus, we anticipate an overstory canopy closure

equal to or greater than 75 percent with a

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

7.2 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

1014
11

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality. In addition, we assume that minimal

regeneration would occur over 50 years based on

the degraded habitat conditions. Subsequently,

under the future without project scenario, basal

areas decreased from time year 0 to 50.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the high benefit areas would receive the

most benefits from freshwater flows, nutrients, and

sediments; thus, those areas should see the greatest

increase in growth. These assumptions are similar

to those by Hamilton and Shaffer (2001) for the

Maurepas Diversion Project. Results of studies by

John Day in wetlands receiving secondary treated

sewage suggest that introduction of nutrients as well

as sediments from river water could stimulate

production by 3-5 fold (Hamilton and Shaffer

2001). Comparison of productivity in swamps that

are either managed, have more favorable hydrology,

and/or are receiving nutrient enrichment suggest

that the existing level of productivity in Maurepas

are 1⁄2 to 1⁄4 of average values. As a conservative

projection, we assume growth rates to be 167% of

current growth in the primary impact areas, which is

the same assumption used in the PPL 12 WVA.

Percent composition of cypress trees was adjusted

over the 50 years to mimic conditions in healthier

portions of the project area. Basal area was

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 –

At present the Maurepas Swamp within the project

1015
12

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1 – 50 –

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

1016
13

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season to increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 ppt from TY 1-10).

Because of the anticipated increase in sea level rise

over time, however, we assume an increase in mean

high salinities of 1.0 and 1.2 ppt for TY 25 and 50,

respectively.

• 20 - 30 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

60 percent with an approximate midstory cover of

approximately 35 percent. [Class 4]

Future Without Project

Target Year 1 –

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

1017
14

Class 4.

Future Without Project

Target Years 10 – 50 –

Continued degradation of the area is anticipated

under the future without project scenario. Because

of this, we assumed that overstory closure would be

reduced to less than 50 percent by TY10 (Class 2)

and less than 33 percent by TY25 (Class 1).

Future With Project

Target Year 1 –

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

Future With Project

Target Year 10 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25 – 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

1018
15

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

7.9 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was

estimated based on data collected by Southeast

Louisiana University over the past 10 years and

percent composition of canopy trees was estimated

based on best professional judgment. Within the

PPL 12 WVA it was assumed that 50 percent of the

tupelo et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality occurring within the 10 year to marsh

habitat type. Because habitat quality and conditions

1019
16

are higher in the 20 year to marsh habitat type, as

compared to the 10 year to marsh habitat type, we

assume that tupelo mortality would occur, but at a

slower rate. Therefore, we predict that 50 percent

of the tupelo et al would die over the 50 year project

life. Subsequently, under the future without project

scenario, basal areas decreased from time year 0 to

50.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the primary impact areas would receive

the most benefits from freshwater flows, nutrients,

and sediments; thus, those areas should see the

greatest increase in growth. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 167% of current growth in the

high benefit areas, which is the same assumption

used in the PPL 12 WVA. Percent composition of

cypress trees was adjusted over the 50 years to

mimic conditions in healthier portions of the project

area. Basal area was estimated by a bottomland

hardwood growth/basal area calculator developed

by the United States Forest Service (Putnam et al.

1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 –

1020
17

At present the Maurepas Swamp within the project

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1 – 50 –

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

1021
18

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season to increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 parts per thousand

[ppt] from TY 1-10). Because of the anticipated

increase in sea level rise over time, however, we

assume an increase in mean high salinities of 1.0

and 1.2 ppt for TY 25 and 50, respectively.

• 30 -50 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

This information was provided by Bernard Wood

(Research Assistant Southeastern Louisiana

University). Specifically, total canopy cover is

estimated to be between 50 and 75 percent with a

midstory cover greater than 33 percent or a

herbaceous cover greater than 33 percent. [Class 4]

Future Without Project

Target Year 1 –

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

1022
19

Class 4.

Future Without Project

Target Years 10 – 50 –

Continued degradation of the area is anticipated

under the future without project scenario. Because

of this, we assumed that overstory closure would be

reduced to less than 50 percent by TY25 (Class 3)

and less than 33 percent by TY50 (Class 1).

Future With Project

Target Year 1 –

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

Future With Project

Target Year 10 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25 – 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

1023
20

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 –

This information was provided by Bernard Wood

through direct measurement of project area trees.

Future Without Project

Target Years 1 – 50 –

Values based on information provided by Bernard

Wood. Mean dbh for each species was estimated as

the mean existing dbh plus the existing mean annual

growth rate times X number of years (growth rate:

cypress = .15 inches per year tupelo et al = .10

inches per year). Basal area was estimated based on

data collected by Southeast Louisiana University

over the past 10 years and percent composition of

canopy trees was estimated based on best

professional judgment. Within the PPL 12 WVA it

was assumed that 50 percent of the tupelo et al

would die over 20 years, but that actual mortality of

cypress would be minimal. Over the 50 year project

life, we assume that 75 percent of the tupelo et al

would die with minimal cypress mortality occurring

within the 10 year to marsh habitat type. Because

habitat quality and conditions are higher in the 30 -

50 year to marsh habitat type, as compared to the 10

year to marsh habitat type, we assume that tupelo

mortality would occur, but at a slower rate.

Therefore, we predict that 50 percent of the tupelo

et al would die over the 50 year project life.

Subsequently, under the future without project

scenario basal areas decrease slightly from time

year 0 to 25 and decrease significantly between time

year 25 and 50 due to the projected loss of canopy

cover.

Future With Project

1024
21

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA and information provided by Mr. Bernard

Wood. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the primary impact areas would receive

the most benefits from freshwater flows, nutrients,

and sediments; thus, those areas should see the

greatest increase in growth. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 167% of current growth in the

high benefit areas, which is the same assumption

used in the PPL 12 WVA. Percent composition of

cypress trees was adjusted over the 50 years to

mimic conditions in healthier portions of the project

area. Basal area was estimated by a bottomland

hardwood growth/basal area calculator developed

by the United States Forest Service (Putnam et al.

1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 –

At present the Maurepas Swamp within the project

area are temporarily flooded and have low

flow/exchange.

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is expected under

1025
22

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain temporarily flooded

over 50 years.

Future With Project

Target Years 1 – 50 –

We assume that the portions of the proposed project

within the primary impact area would receive the

highest amount of direct benefits from construction

of the gaps and should experience a substantial

increase in substrate accretion and nutrient input. In

addition, being in the immediate area of the

proposed gaps we assume that this area would

receive a high level of flow-exchange. We,

therefore, anticipate a seasonal flood duration with

high flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season to increase to 1.4 ppt over 50 years.

1026
23

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is expected to

occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction

for the first 10 years (i.e., 0.9 ppt from TY 1-10).

Because of the anticipated increase in sea level rise

over time, however, we assume an increase in mean

high salinities of 1.0 and 1.2 ppt for TY 25 and 50,

respectively.

Secondary Impact Areas

• Fresh Marsh – The Swamp Model was chosen for this area over the Fresh Marsh

Model, even though there is less than a 33 percent canopy cover, because the area

provides functions and values more closely associated with a swamp than a fresh

marsh.

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. It was the consensus of the

group that there is less than 33 percent overstory

closure. [Class 1]

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, the

area is expected to remain a Class 1.

Future With Project

Target Year 1 –

1027
24

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 1.

Future With Project

Target Year 10 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. However, cypress trees planted at TY1

would be 11 years old. In Louisiana, the height of

cypress at 10 years of age is, on average, 17 feet

(USDA 1980). Therefore, because there were no

tree species within the midstory at TY 0 and

because planted cypress trees would not be old

enough yet to be considered a component of the

overstory, we anticipate the stand structure would

remain a Class 1.

Future With Project

Target Year 25 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

and would, therefore, be considered a component of

the overstory. Accordingly, we anticipate an

overstory closure of 50 -75 percent with a midstory

or herbaceous cover greater than 33 percent. [Class

4]

Future With Project

Target Year 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

1028
25

planting should continue to improve habitat

conditions within the area. Accordingly, we

anticipate an overstory closure of greater than or

equal to 75 percent with either a midstory cover or

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

6.3 inches determined during our WVA data

collection field assessment. Although our estimate

is on the lower end of the range determined by Mr.

Wood, because the subject area represents some of

the more degraded habitat we feel that this estimate

is representative of existing habitat conditions.

Basal area was estimated based on information

gathered during the aforementioned field visit and

data collected by Southeast Louisiana University

over the past 10 years.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

1029
26

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality. In addition, we assume that minimal

regeneration would occur over 50 years based on

the degraded habitat conditions and lack of tree

species at TY 0 in the understory. Subsequently,

under the future without project scenario, basal

areas decreased from time year 0 to 50.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

receive the benefits from freshwater flows,

nutrients, and sediments; however, to a lesser extent

than the primary impact areas. These assumptions

are similar to those by Hamilton and Shaffer (2001)

for the Maurepas Diversion Project. Results of

studies by John Day in wetlands receiving

secondary treated sewage suggest that introduction

of nutrients as well as sediments from river water

could stimulate production by 3-5 fold (Hamilton

and Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960) and is assumed to result in

similar conditions as the 155 acre fresh marsh high

benefit area since vegetated plantings are proposed.

Variable 3: Water Regime

1030
27

Both Future With and Future Without Project

Target Year 0 –

At present the Maurepas Swamp within this portion

of the project area are semi-permanently flooded

and have low flow/exchange.

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1 – 50 –

We assume that the portions of the proposed project

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

anticipate a semi-permanent flood duration with

moderate flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the ARDC project is further from the lake

(i.e., further from the source of saltwater intrusion)

1031
28

the CWPPRA Environmental Work Group assumed

a lower mean high salinity in this area and adopted

1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

• 10 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

1032
29

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

35 percent with an approximate midstory cover of

17 percent. [Class 2]

Future Without Project

Target Year 1 –

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 2.

Future Without Project

Target Years 10 – 50 –

Continued degradation of the area is anticipated

under the future without project scenario. Because

of the low tree density and degraded condition, we

downgraded the variable to a Class 1.

Future With Project

Target Year 1 –

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 2.

Future With Project

Target Year 10 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. While the majority cypress trees in the

project area (planted at TY1) would be 11 years old,

and would not be old enough yet to be considered a

component of the overstory, other midstory tree

species present at TY 0 (i.e., red maple, green ash,

and water tupelo) would become a component of

the overstory at TY 10. In addition, because

1033
30

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. Thus, we anticipate an

overstory canopy closure between 33 and 50

percent and greater than a 33 percent midstory or

herbaceous cover. [Class 3]

Future With Project

Target Years 25 – 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area. In addition, planted cypress trees are

expected to be over 31 feet at age 26 (USDA 1980)

and would, therefore, be considered a component of

the overstory. Because construction of the gaps is

designed to allow for drainage of the area during

ARDC low flow events, seedling germination,

establishment, and survival is expected to increase.

Thus, we anticipate an overstory canopy closure

equal to or greater than 75 percent with a

herbaceous cover greater than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

6.5 and 8.25 inches, as compared to our average of

7.2 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

1034
31

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality. In addition, we assume that minimal

regeneration would occur over 50 years based on

the degraded habitat conditions. Subsequently,

under the future without project scenario, basal

areas decreased from time year 0 to 50.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

receive the benefits from freshwater flows,

nutrients, and sediments; however, to a lesser extent

than the primary impact areas. These assumptions

are similar to those by Hamilton and Shaffer (2001)

for the Maurepas Diversion Project. Results of

studies by John Day in wetlands receiving

secondary treated sewage suggest that introduction

of nutrients as well as sediments from river water

could stimulate production by 3-5 fold (Hamilton

and Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

1035
32

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 –

At present the Maurepas Swamp within the project

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1 – 50 –

We assume that the portions of the proposed project

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

1036
33

anticipate a semi-permanent flood duration with

moderate flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

1037
34

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

• 20 - 30 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University). Specifically,

total canopy cover is estimated to be approximately

60 percent with an approximate midstory cover of

approximately 35 percent. [Class 4]

Future Without Project

Target Year 1 –

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 4.

Future Without Project

Target Years 10 – 50 –

Continued degradation of the area is anticipated

under the future without project scenario. Because

of this, we assumed that overstory closure would be

reduced to less than 50 percent by TY10 (Class 2)

and less than 33 percent by TY25 (Class 1).

Future With Project

Target Year 1 –

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

1038
35

Future With Project

Target Year 10 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25 – 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

Both Future With and Future Without Project

Target Year 0 –

This information was gathered during a July 30,

2009, field assessment. Those estimates, based on

existing habitat conditions, were consistent with

those found by Bernard Wood (Research Assistant

Southeastern Louisiana University) through direct

measurement of project area trees. His dbh

estimate, for all tree species combined, was between

1039
36

6.5 and 8.25 inches, as compared to our average of

7.9 inches determined during our WVA data

collection field assessment. Basal area was

estimated based on information gathered during the

aforementioned field visit and data collected by

Southeast Louisiana University over the past 10

years.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Mean dbh for each species was estimated

as the mean existing dbh plus the existing mean

annual growth rate times X number of years

(growth rate: cypress = .11 inches per year tupelo

et al = .08 inches per year). Basal area was again

estimated by a bottomland hardwood growth/basal

area calculator developed by the United States

Forest Service (Putnam et al. 1960) and percent

composition of canopy trees was estimated based on

best professional judgment. Within the PPL 12

WVA it was assumed that 50 percent of the tupelo

et al would die over 20 years, but that actual

mortality of cypress would be minimal. Over the 50

year project life, we assume that 75 percent of the

tupelo et al would die with minimal cypress

mortality occurring within the 10 year to marsh

habitat type. Because habitat quality and conditions

are higher in the 20 year to marsh habitat type, as

compared to the 10 year to marsh habitat type, we

assume that tupelo mortality would occur, but at a

slower rate. Therefore, we predict that 50 percent

of the tupelo et al would die over the 50 year project

life. Subsequently, under the future without project

scenario, basal areas decrease from time year 0 to

50.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

1040
37

receive benefits from freshwater flows, nutrients,

and sediments; however, to a lesser extent than the

primary impact areas. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 –

At present the Maurepas Swamp within the project

area are semi-permanently flooded and have low

flow/exchange.

Future Without Project

Target Years 1 – 50 –

Continued degradation of the area is expected under

the future without project scenario. Because the

area has some level of flow/exchange (albeit low),

we anticipate the area to remain semi-permanently

flooded over 50 years.

Future With Project

Target Years 1 – 50 –

1041
38

We assume that the portions of the proposed project

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

anticipate a semi-permanent flood duration with

moderate flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1 – 50 –

1042
39

Values based on information presented in the PPL

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

• 30 -50 Years to Marsh

Variable 1: Stand Structure

Both Future With and Future Without Project

Target Year 0 –

This information was provided by Bernard Wood

(Research Assistant Southeastern Louisiana

University). Specifically, total canopy cover is

estimated to be between 50 and 75 percent with a

midstory cover greater than 33 percent or a

herbaceous cover greater than 33 percent. [Class 4]

Future Without Project

Target Year 1 –

Because of the minimal time lapse since TY0, we

predicted that the stand structure would remain a

Class 4.

Future Without Project

Target Years 10 – 50 –

Degradation of the area is anticipated under the

future without project scenario. Because of this, we

assumed that overstory closure would be reduced to

1043
40

less than 50 percent by TY25 (Class 3) and less than

33 percent by TY50 (Class 1).

Future With Project

Target Year 1 –

Because of the minimal time lapse since project

construction (i.e., 1 year), we predicted that the

stand structure would remain a Class 4.

Future With Project

Target Year 10 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions over

time within the area. In addition, because

construction of the gaps is designed to allow for

drainage of the area during ARDC low flow events,

seedling germination, establishment, and survival is

expected to increase. We do not, however,

anticipate a significant change in stand structure in

this area over 10 years. Therefore, we predicted

stand structure would remain a Class 4.

Future With Project

Target Years 25 – 50 –

The combined effects of increased deposition of

fine-grained sediment, increased nutrient loading,

increased freshwater flows, reduced salinities,

seasonally-lower water levels, and vegetative

planting should improve habitat conditions within

the area over time. Because construction of the

gaps is designed to allow for drainage of the area

during ARDC low flow events, seedling

germination, establishment, and survival is expected

to increase. Thus, we anticipate an overstory

canopy closure equal to or greater than 75 percent

with a herbaceous cover or midstory cover greater

than 33 percent. [Class 6]

Variable 2: Stand Maturity

1044
41

Both Future With and Future Without Project

Target Year 0 –

This information was provided by Bernard Wood

through direct measurement of project area trees.

Future Without Project

Target Years 1 – 50 –

Values based on information provided by Bernard

Wood. Mean dbh for each species was estimated as

the mean existing dbh plus the existing mean annual

growth rate times X number of years (growth rate:

cypress = .15 inches per year tupelo et al = .10

inches per year). Basal area was estimated based on

data collected by Southeast Louisiana University

over the past 10 years and percent composition of

canopy trees was estimated based on best

professional judgment. Within the PPL 12 WVA it

was assumed that 50 percent of the tupelo et al

would die over 20 years, but that actual mortality of

cypress would be minimal. Over the 50 year project

life, we assume that 75 percent of the tupelo et al

would die with minimal cypress mortality occurring

within the 10 year to marsh habitat type. Because

habitat quality and conditions are higher in the 30 -

50 year to marsh habitat type, as compared to the 10

year to marsh habitat type, we assume that tupelo

mortality would occur, but at a slower rate.

Therefore, we predict that 50 percent of the tupelo

et al would die over the 50 year project life.

Subsequently, under the future without project

scenario basal areas decrease slightly from time

year 0 to 25 and decrease significantly between time

year 25 and 50 due to the projected loss of canopy

cover.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Under the future with project scenario,

construction of the gaps is expected to stimulate

productivity and growth of cypress and tupelo. We

assume that the secondary impact areas would

receive benefits from freshwater flows, nutrients,

1045
42

and sediments; however, to a lesser extent than the

primary impact areas. These assumptions are

similar to those by Hamilton and Shaffer (2001) for

the Maurepas Diversion Project. Results of studies

by John Day in wetlands receiving secondary

treated sewage suggest that introduction of nutrients

as well as sediments from river water could

stimulate production by 3-5 fold (Hamilton and

Shaffer 2001). Comparison of productivity in

swamps that are either managed, have more

favorable hydrology, and/or are receiving nutrient

enrichment suggest that the existing level of

productivity in Maurepas are 1⁄2 to 1⁄4 of average

values. As a conservative projection, we assume

growth rates to be 129% of current growth in the

secondary impact areas, which is the same

assumption used in the PPL 12 WVA. Percent

composition of cypress trees was adjusted over the

50 years to mimic conditions in healthier portions of

the project area. Basal area was estimated by a

bottomland hardwood growth/basal area calculator

developed by the United States Forest Service

(Putnam et al. 1960).

Variable 3: Water Regime

Both Future With and Future Without Project

Target Year 0 –

At present the Maurepas Swamp within the project

area are temporarily flooded and have low

flow/exchange.

Future Without Project

Target Years 1 – 50 –

Degradation of the area is expected under the future

without project scenario. Because the area has

some level of flow/exchange (albeit low), we

anticipate the area to remain temporarily flooded

over 50 years.

Future With Project

Target Years 1 – 50 –

We assume that the portions of the proposed project

1046
43

within the secondary impact areas are expected to

see direct benefits from construction of the gaps,

and should experience an increase in substrate

accretion and nutrient input, however, to a lesser

extent than the primary impact areas. Being located

further from the proposed gaps than the primary

impact areas, we assume that the secondary impact

areas would also experience some level of

improvement in flooding duration due to improved

drainage of the swamp, however, not to the extent

of the primary impact areas. We, therefore,

anticipate a temporary flood duration with moderate

flow/exchange.

Variable 4: Mean High Salinity During the Growing Season

Both Future With and Future Without Project

Target Year 0 –

Value based on information presented in the PPL 12

WVA. Specifically, for the Maurepas Diversion

Project it was estimated that typical high salinity

during the growing season would be about 1.4 ppt.

Because the LCA ARDC Modification project is

further from the lake (i.e., further from the source of

saltwater intrusion) the CWPPRA Environmental

Work Group assumed a lower mean high salinity in

this area and adopted 1.2 ppt for the PPL 12 WVA.

Future Without Project

Target Years 1 – 50 –

Values based on information presented in the PPL

12 WVA. Specifically, subsidence is expected to

continue within the project area over time under the

future without project scenario. We, therefore,

assume that the ability for saltwater to intrude

further and/or more frequently into the project area

swamps would likewise increase. Thus, we

assumed that mean high salinity during the growing

season would increase to 1.4 ppt over 50 years.

Future With Project

Target Years 1 – 50 –

Values based on information presented in the PPL

1047
44

12 WVA. Specifically, the proposed project was

designed to allow for freshwater to be introduced

into the swamp when water elevations in the ARDC

are higher than in the swamp, which is anticipated

to occur frequently. This frequent introduction of

freshwater into the system from the ARDC is

expected to result in a mean high salinity reduction.

However, because the secondary impact areas are

located further from the gaps than the primary

impact areas and because the volume of water

would be spread over a larger area we assumed that

mean high salinity benefits would be less in those

areas (1.0 ppt for TY 1 and 10). In addition,

because of the anticipated increase in sea level rise

over time, we assume an increase in mean high

salinities of 1.1 and 1.3 ppt for TY 25 and 50,

respectively.

1048
Low RSLR

Alternative 33

Fresh Marsh Primary Impact Area = 70.88 AAHUs 3544.07 CHUs

10 Years to Marsh Primary Impact Area = 35.22 AAHUs 1761.12 CHUs

10 Years to Marsh Secondary Impact Area = 73.46 AAHUs 3673.10 CHUs

20-30 Years to Marsh Primary Impact Area = 189.49 AAHUs 9474.31 CHUs

20-30 Years to Marsh Secondary Impact Area = 252.42 AAHUs 12621.00 CHUs

30-50 Years to Marsh Primary Impact Area = 27.29 AAHUs 1364.40 CHUs

30-50 Years to Marsh Secondary Impact Area = 40.02 AAHUs 2001.13 CHUs

Spoil Bank Permanent Impacts = -0.55 AAHUs -27.60 CHUs

Spoil Bank Temporary Impacts = -0.23 AAHUs -11.38 CHUs

Fresh Marsh Permanent Impacts = -1.33 AAHUs -66.42 CHUs

10 Years to Marsh Permanent Impacts = -0.71 AAHUs -35.53 CHUs

20-30 Years to Marsh Permanent Impacts = -4.70 AAHUs -235.12 CHUs

30-50 Years to Marsh Permanent Impacts = -1.80 AAHUs -89.89 CHUs

TOTAL 679.46 AAHUs 33973.18 CHUs

Alternative 39

Fresh Marsh Primary Impact Area = 70.88 AAHUs 3544.07 CHUs

Fresh Marsh Secondary Impact Area = 46.79 AAHUs 2339.32 CHUs

10 Years to Marsh Primary Impact Area = 74.19 AAHUs 3709.30 CHUs

10 Years to Marsh Secondary Impact Area = 367.18 AAHUs 18359.20 CHUs

20-30 Years to Marsh Primary Impact Area = 414.69 AAHUs 20734.26 CHUs

20-30 Years to Marsh Secondary Impact Area = 423.23 AAHUs 21161.60 CHUs

30-50 Years to Marsh Primary Impact Area = 152.59 AAHUs 7629.30 CHUs

30-50 Years to Marsh Secondary Impact Area = 75.40 AAHUs 3770.16 CHUs

Spoil Bank Permanent Impacts = -1.59 AAHUs -79.35 CHUs

Spoil Bank Temporary Impacts = -0.77 AAHUs -38.57 CHUs

Fresh Marsh Permanent Impacts = -1.33 AAHUs -66.42 CHUs

10 Years to Marsh Permanent Impacts = -0.99 AAHUs -49.74 CHUs

20-30 Years to Marsh Permanent Impacts = -8.92 AAHUs -445.86 CHUs

30-50 Years to Marsh Permanent Impacts = -9.71 AAHUs -485.42 CHUs

TOTAL 1601.64 AAHUs 80081.84 CHUs

Intermediate RSLR

Alternative 33

Fresh Marsh Primary Impact Area = 66.75 AAHUs 3337.67 CHUs

10 Years to Marsh Primary Impact Area = 34.54 AAHUs 1726.93 CHUs

10 Years to Marsh Secondary Impact Area = 67.45 AAHUs 3372.29 CHUs

20-30 Years to Marsh Primary Impact Area = 183.48 AAHUs 9174.00 CHUs

20-30 Years to Marsh Secondary Impact Area = 232.49 AAHUs 11624.65 CHUs

30-50 Years to Marsh Primary Impact Area = 26.58 AAHUs 1329.14 CHUs

30-50 Years to Marsh Secondary Impact Area = 37.91 AAHUs 1895.65 CHUs

Spoil Bank Permanent Impacts = -0.55 AAHUs -27.60 CHUs

Spoil Bank Temporary Impacts = -0.23 AAHUs -11.38 CHUs

Fresh Marsh Permanent Impacts = -1.32 AAHUs -66.22 CHUs

10 Years to Marsh Permanent Impacts = -0.66 AAHUs -32.80 CHUs

20-30 Years to Marsh Permanent Impacts = -4.37 AAHUs -218.27 CHUs

30-50 Years to Marsh Permanent Impacts = -1.76 AAHUs -88.17 CHUs

TOTAL 640.32 AAHUs 32015.90 CHUs

1049
Alternative 39

 Fresh Marsh Primary Impact Area = 66.75 AAHUs 3337.67 CHUs

 Fresh Marsh Secondary Impact Area = 42.53 AAHUs 2126.41 CHUs

 10 Years to Marsh Primary Impact Area = 72.75 AAHUs 3637.31 CHUs

 10 Years to Marsh Secondary Impact Area = 337.11 AAHUs 16855.69 CHUs

 20-30 Years to Marsh Primary Impact Area = 408.90 AAHUs 20444.99 CHUs

 20-30 Years to Marsh Secondary Impact Area = 389.82 AAHUs 19491.03 CHUs

 30-50 Years to Marsh Primary Impact Area = 148.64 AAHUs 7432.12 CHUs

 30-50 Years to Marsh Secondary Impact Area = 71.43 AAHUs 3571.43 CHUs

 Spoil Bank Permanent Impacts = -1.59 AAHUs -79.35 CHUs

 Spoil Bank Temporary Impacts = -0.77 AAHUs -38.57 CHUs

 Fresh Marsh Permanent Impacts = -1.32 AAHUs -66.22 CHUs

 10 Years to Marsh Permanent Impacts = -0.92 AAHUs -45.92 CHUs

 20-30 Years to Marsh Permanent Impacts = -8.28 AAHUs -413.90 CHUs

 30-50 Years to Marsh Permanent Impacts = -9.52 AAHUs -476.11 CHUs

TOTAL 1515.53 AAHUs 75776.57 CHUs

High RSLR

Alternative 33

Fresh Marsh Primary Impact Area = 58.99 AAHUs 2949.66 CHUs

10 Years to Marsh Primary Impact Area = 31.57 AAHUs 1578.35 CHUs

10 Years to Marsh Secondary Impact Area = 67.08 AAHUs 3354.07 CHUs

20-30 Years to Marsh Primary Impact Area = 170.56 AAHUs 8528.05 CHUs

20-30 Years to Marsh Secondary Impact Area = 226.61 AAHUs 11330.35 CHUs

30-50 Years to Marsh Primary Impact Area = 26.42 AAHUs 1320.83 CHUs

30-50 Years to Marsh Secondary Impact Area = 37.46 AAHUs 1873.22 CHUs

Spoil Bank Permanent Impacts = -0.55 AAHUs -27.60 CHUs

Spoil Bank Temporary Impacts = -0.23 AAHUs -11.38 CHUs

Fresh Marsh Permanent Impacts = -1.30 AAHUs -64.90 CHUs

10 Years to Marsh Permanent Impacts = -0.62 AAHUs -31.24 CHUs

20-30 Years to Marsh Permanent Impacts = -4.16 AAHUs -207.75 CHUs

30-50 Years to Marsh Permanent Impacts = -1.63 AAHUs -81.71 CHUs

TOTAL 610.20 AAHUs 30509.94 CHUs

Alternative 39

 Fresh Marsh Primary Impact Area = 58.99 AAHUs 2949.66 CHUs

 Fresh Marsh Secondary Impact Area = 40.91 AAHUs 2045.66 CHUs

 10 Years to Marsh Primary Impact Area = 66.49 AAHUs 3324.36 CHUs

 10 Years to Marsh Secondary Impact Area = 335.10 AAHUs 16754.90 CHUs

 20-30 Years to Marsh Primary Impact Area = 373.27 AAHUs 18663.39 CHUs

 20-30 Years to Marsh Secondary Impact Area = 379.95 AAHUs 18997.57 CHUs

 30-50 Years to Marsh Primary Impact Area = 147.71 AAHUs 7385.67 CHUs

 30-50 Years to Marsh Secondary Impact Area = 70.58 AAHUs 3529.16 CHUs

 Spoil Bank Permanent Impacts = -1.59 AAHUs -79.35 CHUs

 Spoil Bank Temporary Impacts = -0.77 AAHUs -38.57 CHUs

 Fresh Marsh Permanent Impacts = -1.30 AAHUs -64.90 CHUs

 10 Years to Marsh Permanent Impacts = -0.87 AAHUs -43.74 CHUs

 20-30 Years to Marsh Permanent Impacts = -7.88 AAHUs -393.96 CHUs

 30-50 Years to Marsh Permanent Impacts = -8.82 AAHUs -441.21 CHUs

TOTAL 1451.77 AAHUs 72588.63 CHUs

1050
47

WVA Data

Figure 1 depicts the acreages utilized as input for the WVA model. These acreages represent each habitat

type (20-30 years to marsh, marsh, etc.) separated out into the primary and secondary impact areas for the

final array of alternatives.

Figures 2 – 6 depict the construction footprint in acres for the bifurcated conveyance channels

implemented within the final array of alternatives.

Primary and Secondary Impact Areas

The primary and secondary impact areas for the final array of alternatives were developed after

examining existing conveyance channels found within the study area. These channels are considered to be

in a state of hydrologic equilibrium due to the lack of sediment buildup observed, when compared to other

channels found within the same general area. The benefit areas for the proposed conveyance channels

were developed by observing the dimensions and configurations of the drainage areas found along these

existing channels.

The primary impact area would have more flow exchange and therefore more sediments and nutrients

than the secondary impact area. The volume of water, which transports sediments and nutrients, is

dependent on the duration of high stages in the ARDC. During the short duration of high stages in the

ARDC, the benefits may be limited to the primary impact area. During normal hydrologic cycles, the

primary impact area would receive a higher flow exchange than the secondary impact area.

1051
48

Figure 1. Input Acreages for WVA Model

1052
49

Figure 2. WVA Acreages for Alternative 33 Cut A

1053
50

Figure 3. WVA Acreages for Alternative 33 Cut B

1054
51

Figure 4. WVA Acreages for Alternative 33 Cut C

1055
52

Figure 5. WVA Acreages for Alternative 34

1056
53

Figure 6. WVA Acreages for Alternative 35

1057
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana Source: USGS/GEC

Scale:

Date: February 2010

WETLAND VALUE ASSESSMENT AREAS

FOR ALTERNATIVE 35

Map ID: 27850108-1859

Amite River Diversion Canal

0.9 acres Temporary

Impact to Dredged

Material Berm

7.3 acres Permanent

Impact to Existing Swamp:

20-30 Years to Marsh

3.6 acres Permanent

Impact to Existing Swamp:

30-50 Years to Marsh

0.9 acres Temporary

Impact to Dredged

Material Berm

0.6 acres Permanent

Impact to Dredged

Material Berm

1:6,000

0 200 400 600

Feet

Map Extent

NE-1 NE-2

SE-2

SE-1 SW-2

NW-2

Amite River

NE-3

Diversion Canal

Legend

Subunits

Primary Impact Area

Secondary Impact Area

Habitat Types

20-30 Years to Marsh

30-50 Years to Marsh

Wetland Value Assessment Areas

Permanent Impact to Existing Swamp

Permanent Impact to Dredged Material Berm

Temporary Impact to Dredged Material Berm

SE-1

Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Figure: 6

1058
Summary of acreages for each alternative by habitat type used in the WVA and benefits analysis

Alternative Permanent Temporary Sub Total Marsh 10 Years to Marsh 2030 Years to Marsh 3050 Years to Marsh Sub Total Total Existing Marsh 10 Years to Marsh 2030 Years to Marsh 3050 Years to Marsh Sub Total Existing Marsh 10 Years to Marsh 2030 Years to Marsh 3050 Years to Marsh Sub Total Total for Benefits Areas

33 Cut A 0.3 0.6 0.9 0.0 0.0 7.0 3.0 10.0 11.8

33 Cut B 0.2 0.6 0.8 6.5 0.0 2.4 0.0 8.9 10.5

33 Cut C 0.3 0.6 0.9 3.1 2.5 4.1 0.0 9.7 11.5

33 0.8 1.8 2.6 9.6 2.5 13.5 3.0 28.6 31.2 144.1 65.9 353.9 81.8 645.7 0.0 175.5 621.4 159.5 956.4 1,602.1

34 0.9 2.5 3.4 0.0 1.0 4.8 9.6 15.4 18.8 0.0 72.9 151.8 201.6 426.3 146.3 701.7 147.3 37.4 1,032.7 1,459.0

35 0.6 1.8 2.4 0.0 0.0 7.3 3.6 10.9 13.3 0.0 0.0 268.8 174.0 442.8 0.0 0.0 273.2 103.6 376.8 819.6

36 1.7 4.3 6.0 9.6 3.5 18.3 12.6 44.0 50.0 144.1 138.8 505.7 283.4 1,072.0 146.3 877.2 768.7 196.9 1,989.1 3,061.1

37 1.5 4.3 5.8 0.0 1.0 12.1 13.2 26.3 32.1 0.0 72.9 420.6 375.6 869.1 146.3 701.7 420.5 141.0 1,409.5 2,278.6

38 1.4 3.6 5.0 9.6 2.5 20.8 6.6 39.5 44.5 144.1 65.9 622.7 255.8 1,088.5 0.0 175.5 894.6 263.1 1,333.2 2,421.7

39 2.3 6.1 8.4 9.6 3.5 25.6 16.2 54.9 63.3 144.1 138.8 774.5 457.4 1,514.8 146.3 877.2 1,041.9 300.5 2,365.9 3,880.7

Existing Swamp (Permanent) Primary Impact Area Secondary Impact Area Dredged Material Berm

Benefits Area Construction Area

55

1059

WVA Model Certification--Comments and Responses

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. The WVA swamp model has only two graphs. One of

them, V2 - Stand Maturity, has a zero intercept. The other, Salinity, does

not. However, McKay and Fischenich (1) did a sensitivity analysis on the

Barataria Barrier Shoreline WVA. Their study showed that the application

of the zero slope intercept instead of 0.1 as in the model did not affect the

relative rankings of any of the alternatives. The same is likely to be true for

the ARDC Modification project.

3. The number of target years should be increased to improve

the predictive ability of the models given that changes are often nonlinear. For the LCA ARDC Modification project, different alternatives were

analyzed using target years depending upon various assumptions such as the

health of the vegetation relative to similar vegetation in the swamp outside of

the project area as reflected in the habitat classification map (20-30 years to

marsh, 30-50 years to marsh, and >50 years to marsh). The target years (TY)

used for the LCA ARDC Modification project were TY0, TY1, TY20, TY30,

and TY 50.

For the WVA Certification, additional text has been provided in the

Procedural Manual to guide users on the selection of target years. A table

has been added summarizing, by project type, the use of specific target years

to reflect aspects of project evolution. Suggestions have been made for

ensuring the justification for the selection of target years is added to the

Project Information Sheet.

4. In the spreadsheet for the marsh model, open water and

emergent marsh AAHUs are incorrectly combined and should be

added rather than taking the arithmetic mean. The marsh models

were not used in the LCA ARDC Modification project.

6. Sea level is an important driver and relative sea level rise

and climate change should be included in the models. For the LCA

ARDC Modification project, relative sea level and subsidence were accounted

for in the land loss rates calculated for each project area. Data in the

literature indicated that the rate of accretion will offset sea level rise and

subsidence. The hydrologic modeling that was used to evaluate WVA metrics

for the ARDC used the intermediate rate of sea level rise.

57

1061
For WVA Certification, a new section Climate Change has been added

to the Procedural Manual to provide guidance on how to consider sea-level

rise and other climate change effects in the evaluation. Suggestions have

been made to document in the Project Information Sheet how these factors

are considered in the evaluation.

10. For some model variables, policy decisions appear to

supersede the biology of the relationships for developing the

Suitability Index (SI) curves. This comment referred to a problem that

the reviewers had with the marsh models. The marsh models were not used

in the LCA ARDC Modification project.

11. The spreadsheets for the models as created are likely to

lead to errors in maintenance and use. The United States Fish and

Wildlife Service (USFWS) Habitat Evaluation Team (HET) member for the

LCA ARDC Modification project is experienced in the use of WVA

spreadsheets. To ensure that "% cover" and "class," as well as other

spreadsheet numbers were entered correctly, the spreadsheet entries have

been and will be reviewed by several members of the HET (e.g., agency

representatives).

For WVA Certification, the spreadsheets have been corrected as

Battelle suggested to correct calculation errors, improve the spreadsheet user

interface, and decrease the likelihood of user errors.

12. Several inaccuracies were identified in the model

spreadsheets that should be corrected. As explained above, the USFWS

HET member is experienced in the use of WVA spreadsheets and the HET

reviewed all spreadsheets. According to model developers, the spreadsheet

works correctly for the Swamp WVA V2.

For WVA Certification, the spreadsheets have been corrected as

Battelle suggested to correct calculation and specification errors.

15. The WVA method should be expanded to handle risk and

uncertainty in areas exposed to episodic events. Risk and uncertainty

are already incorporated into the WVA model used for the LCA ARDC

Modification project. Risk and uncertainty are also addressed in Section 3.8

of the Integrated Feasibility Study and Draft Supplemental Environmental

Impact Statement (DSEIS) and include hydrologic, environmental, and

construction and economic uncertainties.

58

1062
59

For WVA Certification, suggestions have been made to add a section to

the Project Information Sheet to describe how risk and uncertainty are

considered in the evaluation.

16. The WVA method should be updated, taking into account

new GIS data, LIDAR, and other new data sources as well as model

formats/presentation (visualization tools, HGM). The WVA model used

for the LCA ARDC Modification project included the use of the most recent

imagery and land loss data available from the (U.S. Geological Survey) USGS

as well as the most appropriate historic imagery to determine land loss and

habitat conversion. The habitat classification map was developed by

scientists with the most knowledge about the condition of wetlands in

Maurepas Swamp in conjunction with the most recent available imagery from

the USGS.

For WVA Certification, the Procedural Manual has been updated to

reflect current use and to provide appropriate guidance on available data

sources.

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. The WVA Swamp Model used for the LCA ARDC

Modification project uses a geometric mean to derive HSIs.

1063

SECTION 2

1065

LOUISIANA COASTAL AREA

AMITE RIVER DIVERSION CANAL MODIFICATION

INTEGRATED FEASIBILITY STUDY AND

ENVIRONMENTAL IMPACT STATEMENT

IWR CE/ICA ANALYSIS

ECONOMICS APPENDIX

APPENDIX K

1067

1

Cost Effective and Incremental Cost Analyses

Introduction

For environmental planning, where traditional benefit-cost analysis is not possible

because costs and benefits are expressed in different units, two analytical methods are

used to assist Corps planners in the decision process. First, cost effectiveness analysis is

conducted to ensure that the least cost solution is identified for each possible level of

environmental output. Subsequent incremental cost analysis of the cost effective

solutions is conducted to reveal changes in costs for increasing levels of environmental

outputs. In the absence of a common measurement unit for comparing the non-monetary

benefits with the monetary costs of environmental plans, cost effectiveness and

incremental cost analysis are valuable tools to assist in decision making.

It is important to keep in mind that the most useful information developed by these two

methods is what it tells decision makers about the relative relationships among solutions

– that one would likely produce greater output than another, or one is likely to be more

costly than another – rather than the specific numbers that are calculated. Furthermore,

these analyses would usually not lead, and are not intended to lead, to a single best

solution (as in economic cost-benefit analysis); however, they would improve the quality

of decision making by ensuring that a rational, supportable approach is used in

considering and selecting alternative methods to produce environmental outputs.

The cost-effectiveness and incremental cost analyses are performed with the Institute of

Water Resources IWR-Plan software. This software takes the annualized costs, as

determined by a preliminary cost estimate, and the annualized benefits (Average Annual

Habitat Units) (AAHUs), as determined by the Wetland Value Assessment (WVA)

model, for each of the alternatives in the final array, including the No-Action Alternative.

From this data, an analysis of cost-effectiveness and incremental cost is run between each

alternative, at which point the software determines if any of the alternatives are

determined to be cost-effective. A cost-effective alternative is one which produces the

greater benefits (AAHUs) with the same cost as other alternatives. From this analysis, a

frontier is formed on the cost benefit plot (Figure 1). Anything above this frontier is

considered cost-effective. Additionally, an incremental cost analysis is run between each

of the alternatives included in the IWR Planning Suite analysis. The incremental cost

analysis compares the differential in cost and benefits (the slope of the line connecting

two alternatives on the cost/benefit plot) for each alternative to the alternatives with

similar cost and benefit characteristics. The alternatives which exhibit comparably

greater differentials are characterized as a Best Buy. A Best Buy represents the

alternatives with maximized incremental benefit to cost increase when compared to the

previous incremental benefit and cost comparison.

Amite River Diversion Canal Modification

This study evaluated several alternatives designed to restore freshwater swamp habitat

within the western Maurepas Swamp, which is recognized as a vital national resource.

1069
2

The intent is to restore the degraded areas within the study area by restoring hydrologic

connectivity, increasing nutrient and sediment input into the areas of impact and to

promote the healthy regeneration of cypress/tupelo swamp habitat. In this analysis, eight

environmental restoration alternatives are being evaluated. These alternatives include the

No-Action Alternative, along with Alternatives 33 through 39. Alternatives 33, 34, and

35 are considered stand-alone alternatives, while Alternatives 36 through 39 are

combinations of the aforementioned stand-alone alternatives. Therefore, the final array

represents all possible combinations of Alternatives 33, 34, and 35. It should also be

noted that, based on feedback from Dr. Gary Shaffer of the University of Southeastern

Louisiana, vegetative plantings are considered a critical component of the restoration

process. Therefore, vegetative plantings were included in all alternatives proposed in the

most-highly degraded areas in the study area (Alternative 33 and 34). Table K.1 displays

the expected environmental outputs in terms of average annual habitat units, the

annualized costs for each restoration alternative, and the annualized cost per AAHU.

Average annual costs (reflecting 2008 price levels) were calculated using the Federal

discount rate of 4.375 percent and assuming a 50-year period of analysis.

Table 1. Cost and Benefit Breakdown for Final Array of Alternatives

Alternative

Acres

of

Benefit

AAHUs

Total

Construction

Cost

Annualized

Cost**

Annualized

Cost/AAHU

35* 820 334 $1,090,000 $61,000 $180

38* 2,422 1,013 $4,550,000 $236,000 $230

37 2,279 922 $4,210,000 $217,000 $240

39* 3,881 1,602 $7,700,000 $394,000 $250

36 3,061 1,268 $6,870,000 $352,000 $280

33 1,602 679 $3,780,000 $197,000 $290

34 1,459 589 $3,370,000 $174,000 $300

*Best Buy

** Discount Rate of 4.375% used over six-year construction period

IWR Results

The results of the IWR-Plan Software Suite analysis determined that all eight of the

restoration alternatives are considered cost-effective (Table 2). In addition, the NoAction Alternative, Alternative 35, Alternative 38, and Alternative 39 were designated as

Best Buys. By default, the No-Action Alternative and the alternative with the maximum

output (Alternative 39) are considered Best Buys by the IWR-Plan Software Suite.

Therefore, it is evident that there is not a significant difference in the incremental cost to

incremental benefit ratio between the other six restoration alternatives. Figure 1

represents the cost-effective frontier of the eight proposed restoration alternatives. Figure

2 depicts a plot of annualized costs vs. annualized benefits for all eight alternatives

analyzed.

1070
3

Table 2. IWR Results

Alternative Annualized Cost Output

(AAHUs) Cost Effective?

No Action Plan $0 0 Best Buy

35 $61,000 334 Best Buy

34 $174,000 589 Yes

33 $197,000 679 Yes

37 $217,000 922 Yes

38 $236,000 1013 Best Buy

36 $351,000 1268 Yes

39 $394,000 1602 Best Buy

Figure 1. Cost-Effective Frontier

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4

Figure 2. Benefit vs. Cost Plot

1072
5

Background of CE/ICA Analysis

The following analysis is based on an Environmental Studies report produced by the US

Army Corps of Engineers entitled, “Cost Effectiveness Analysis for Environmental

Planning: Nine Easy Steps.” The analysis was started at Step 4 (since the Array of

Alternatives has already been determined) as directed by the document.

Step 4: None of the alternatives have the same output; therefore they are All Cost

Efficient.

Step 5: All are Cost Effective

Table 1: Step 5 – Cost Effective Solutions

Alternative Output

(AAHUs)

Annualized Cost

(AAC)

Cost

Effective?

No-Action 0 $0 Yes

35 334 $60,956 Yes

34 589 $173,671 Yes

33 679 $196,686 Yes

37 922 $217,220 Yes

38 1013 $236,293 Yes

36 1268 $351,365 Yes

39 1602 $394,171 Yes

Figure 1: Step 5 – Cost Effective Solutions

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6

Step 6: Calculate Average Costs

Table 2: Step 6 – Average Costs

Alternative Output

(AAHUs)

Annualized Cost

(AAC) AAC/AAHU

No-Action 0 $0 $0 Dropped from Further

Analysis

35 334 $60,956 $182.50 Lowest Average Cost

34 589 $173,671 $294.86

33 679 $196,686 $289.67

37 922 $217,220 $235.60

38 1013 $236,293 $233.26

36 1268 $351,365 $277.10

39 1602 $394,171 $246.05

Step 7: Average Costs for Additional Output

Table 3: Step 7A – First Recalculation

Alternative Output

(AAHUs)

Additional

Output

(AAHU)

Annualized

Cost

Average Cost for

Additional Output

35 334 0 $60,956 ---

34 589 255 $173,671 $442

33 679 345 $196,686 $393

37 922 588 $217,220 $266

38 1013 679 $236,293 $258

36 1268 934 $351,365 $311

39 1602 1268 $394,171 $263

Table 4: Step 7B – Second Recalculation

Alternative Output

(AAHUs)

Additional

Output

(AAHU)

Annualized

Cost

Average Cost

for

Additional

Output

38 1013 0 $236,293 ---

36 1268 255 $351,365 $451

39 1602 589 $394,171 $268

1074
7

Table 5: Step 7C – Summary of Results

Average Cost for Additional Output

Alternative Original Step 7A Step 7B

No-Action -

35 $183 ---

34 $295 $442

33 $290 $393

37 $236 $266

38 $233 $258 ---

36 $277 $311 451.26275

39 $246 $263 268.04414

Table 6: Step 7D – Solutions with Lowest Average Costs for Additional Output

Alternative Output

(AAHUs)

Annualized

Cost

No-Action 0 $0

35 334 $60,956

38 1013 $236,293

39 1602 $394,171

Step 8: Calculate Incremental Costs

Table 7: Step 8A –Incremental Costs

Alternative Output

(AAHUs)

Annualized

Cost

Additional

Output

(AAHU)

Additional

Annualized

Cost

Incremental

Cost ($ per

AAHU)

No-Action 0 $0 --- --- ---

35 334 $60,956 334 $60,956 $183

38 1013 $236,293 679 $175,337 $258

39 1602 $394,171 589 $157,878 $268

Table 8: Step 8B – Solutions with Lowest Average Costs for Additional Output

Alternative Output

(AAHUs)

Annualized

Cost Incremental Cost ($ per AAHU)

No-Action 0 $0 ---

35 334 $60,956 $183

38 1013 $236,293 $233

39 1602 $394,171 $246

1075
8

Figure 2: Step 8 – Incremental Cost

1076
9

Step 9: Comparison and Justification of Successive Incremental Outputs and Costs

Table 9: Step 9 – Justification

Alternative Output

(AAHUs)

Annualize

d Cost

Additional

Output

(AAHU)

Additional

Annualized

Cost

Incremental

Cost ($ per

AAHU)

Justified?

Worth It?

No-Action 0 $0 --- --- ---

35 334 $60,956 334 $60,956 $183 Yes

38 1013 $236,293 679 $175,337 $258 Yes

39 1602 $394,171 589 $157,878 $268 Yes

1077

APPENDIX L

ENGINEERING APPENDIX

1079

TOC-i

Appendix L

ENGINEERING

TABLE OF CONTENTS

Section Page

1 INTRODUCTION............................................................................................. 1-1

2 HYDRAULICS AND HYDROLOGY................................................................. 2-1

Annex - Hydraulics and Hydrology

3 SURVEY DATA ...............................................................................................3-1

Annex - Survey Data

4 GEOLOGY ................................................................................................... 4-1

5 GEOTECHNICAL INVESTIGATION................................................................ 5-1

6 CONCEPTUAL DESIGN ALTERNATIVES EXPLORED .................................6-1

7 DESIGN ...................................................................................................7-1

Cross Sections

8 CONSTRUCTION PROCEDURES ................................................................. 8-1

9 OMRR&R ...................................................................................................9-1

10 COST ESTIMATES ....................................................................................... 10-1

Annex - Cost

Annex 10-1

Annex 10-2

11 SCHEDULE FOR DESIGN AND CONSTRUCTION ..................................... 11-1

12 RELOCATIONS............................................................................................. 12-1

1081


1082
Section 1

INTRODUCTION

1083



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1085



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1086
Section 2

HYDRAULICS AND HYDROLOGY

1087



Section 2

HYDRAULICS AND HYDROLOGY

GENERAL

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1089


1090
ANNEX

Hydraulics and Hydrology

1091

2-3

H&H Modeling Summary

Taylor Engineering used the USACE Hydrologic Engineering Center River Analysis System

(HEC-RAS) program to model the No Action Plan and the With Project Plan. The development

of the models is to simulate the flow in the proposed channels and stage duration data in the

benefit areas.

Due to time and funding constraints for this study, HEC-RAS (1-D, unsteady state) was selected

for the analysis. Due to the accelerated schedule for the project, only existing data was used; no

new stage data was collected. The HEC-RAS model was used to support the WVA of the

proposed project. The model results are used to quantify flow/exchange and flooding duration

(Variable V3) in the WVA calculations.

HEC-RAS Model Calibration

The HEC-RAS unsteady state routine simulates channels and adjacent floodplain swamps as a

one-dimensional hydrodynamic system. Taylor Engineering used U. S. Geological Survey

(USGS) stream gage data for the upstream boundary condition (inflow hydrograph) and for the

downstream boundary condition (stage hydrograph). During the calibration process, the initial

attempts to calibrate the model used a channel and vertical N-values. N-values were adjusted to

very high values in an attempt to simulate observed flow patterns. The computed stages in the

storage areas were compared to gage data in the swamp. The best fit of the computed stages

when compared to the gage data was achieved when the flow between the ARDC and the swamp

was simulated using a culvert for low flow and a weir to simulated high flow conditions. No data

was available to validate the model. Chapter 2 describes the development of the HEC-RAS

model, calibrated with 2005 data from two Louisiana Coastal Protection and Restoration

Authority (CPRA) swamp gages.

HEC-RAS Model Simulation of Alternative PlansThe HEC-RAS models were developed and

used to support the WVA. Water Regime (variable V3) in the WVA considers the flood duration

and the flow/exchange. The flooding duration categories are Seasonal, Temporary, Semipermanent, and Permanent. The Flow/Exchange categories are High, Moderate, Low, and None.

Output data from the HEC-RAS was used to estimate the consecutive number of days was used

as an indicator of flood duration and the computed discharge in the proposed channels was used

as an indicator for the flow/exchange.

To simulate the No Action Plan and the ARDC modification, Taylor Engineering conducted

long-term hydrologic simulations of the study area based on average daily discharge and daily

stages for the 10-year period from January 1, 1999 to December 31, 2008. Extracted estimates of

flood and drying days established the current or baseline conditions needed to evaluate the

proposed alternatives. Chapter 3 describes the HEC-RAS modeling for the No Action Plan and

the With Project Plan, which represented seven different alternatives, and presents the results.

1093
2-4

Tables 1 through 3 present model results for the No Action Plan and the With Project Plan. Table

1 presents a summary of the computed flows in the exchange channels. Tables 2 and 3 present a

comparison of stage duration (in days) for the swamp storage areas in SE-1 and NE-2. Table 2

combines results for the two exchange channels in this area. Table 2 shows that the With Project

Plan increases the percentage of days in SE-1 with Water Surface Elevation (WSE) at or below

1.0 foot from 6 to 37%. Table 3 shows the With Project Plan increases the number of days with

WSE at or below 1.0 foot from 7 to 48% in NE-2.

Table 1 Computed Flow

With Project (no flow in the No Action Plan)

Exchange Channel SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 6330 5298 4812 4368 4035

% time of inflow 23% 22% 29% 28% 28%

Volume outflow (ac-ft/yr) 6874 7160 3392 3696 4088

% time of outflow 77% 78% 71% 72% 72%

Table 2 Stage Duration, Storage Area SE-1

No Action

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 213 2283 2742 2935 3059 3151

% time at or below WSE 6% 62% 75% 80% 84% 86%

Consecutive Days at or below WSE 73 120 138 164 203 204

With Project

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 1352 2390 2770 2950 3070 3160

% time at or below WSE 37% 65% 76% 81% 84% 86%

Consecutive Days at or below WSE 114 121 152 164 203 205

Table 3 Stage Duration, Storage Area NE-2

No Action

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 241 2306 2834 3027 3144 3233

% time at or below WSE 7% 63% 78% 83% 86% 88%

Consecutive Days at or below WSE 64 148 184 203 204 205

1094
2-5

With Project

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 1750 2501 2865 3032 3153 3236

% time at or below WSE 48% 68% 78% 83% 86% 89%

Consecutive Days at or below WSE 117 150 185 204 204 205

Relative Sea Level Rise

Taylor Engineering evaluated the potential hydrologic impact on the No Action Plan and the

modification alternatives for estimates of relative sea level rise (RSLR) in accordance with

guidance provided by the USACE, New Orleans District. Chapter 4 describes the analysis of

RSLR effects on the alternative plans and provides the results.

Taylor Engineering reran the HEC-RAS models for the No Action Plan and the With Project

Plan for 2061 (Year-50) for the three RLSR cases by adding 1.5, 1.9, and 3.2 feet to the Amite

River at Maurepas hydrograph downstream boundary condition. Tables 4, 5, and 6 present model

results. Table 4 includes the previous results (Year 1) for computed flows in the exchange

channels versus computed Year 50 flows for low, intermediate, and high RSLR. Tables 5 and 6

provide similar comparisons of stage durations for the previously computed Year 1 versus Year

50 low, intermediate, and high RSLR for the No Action Plan and With Project Plan in SE-1 and

NE-2, respectively.

Table 4 demonstrates that as stages increase in Lake Maurepas due to RSLR, the flow in the

proposed new exchange channels increase.

Tables 5 and 6 show that RSLR will dramatically reduce the stage duration below 1.0 foot with

both the No Action Plan and the With Project Plan. The percentage of days with WSE below 1.0

foot in the SE-1 and NE-2 areas falls from 37 and 48%, respectively, to zero under all three

RSLR cases.

1095
2-6

Table 4 Computed Exchange Channel Flows with RSLR

With project with no RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 6330 5298 4812 4368 4035

% time of inflow 23% 22% 29% 28% 28%

Volume outflow (ac-ft/yr) 6874 7160 3392 3696 4088

% time of outflow 77% 78% 71% 72% 72%

With Project with 50 years of Low rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 23175 20734 14522 13503 12903

% time of inflow 35% 34% 54% 53% 52%

Volume outflow (ac-ft/yr) 32635 35202 7291 8187 8894

% time of outflow 65% 66% 46% 47% 48%

With Project with 50 years of Intermediate rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 28332 25659 15172 14131 13480

% time of inflow 36% 35% 56% 55% 54%

Volume outflow (ac-ft/yr) 41868 45382 7324 8397 9234

% time of outflow 64% 65% 44% 45% 46%

With Project with 50 years of High rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 36013 33138 15622 14617 14028

% time of inflow 39% 38% 56% 54% 52%

Volume outflow (ac-ft/yr) 57802 63338 74145 9374 11222

% time of outflow 61% 62% 44% 46% 48%

1096
2-7

Table 5 Stage Duration with RSLR, Storage Area SE-1

No Action Plan With Project Plan

Without RSLRWater Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 213 2283 2742 2935 3059 3151 1352 2390 2770 2950 3070 3160% time at or below WSE 6% 62% 75% 80% 84% 86% 37% 65% 76% 81% 84% 86%Consecutive Days at or below WSE 73 120 138 164 203 204 114 121 152 164 203 205With Project with Low rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 15 60 89 120 0 8 62 104 162 206% time at or below WSE 0% 0% 0% 2% 2% 3% 0% 0% 2% 3% 4% 6%Consecutive Days at or below WSE 0 0 2 7 9 12 0 2 7 10 16 22With Project with Intermediate rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 3 7 0 0 3 12 24 38% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1% 1%Consecutive Days at or below WSE 0 0 0 0 1 2 0 0 1 3 3 3With Project with High rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%Consecutive Days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0

1097
2-8

Table 6 Stage Duration with RSLR, Storage Area NE-2

No Action Plan With Project Plan

Without RSLRWater Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 241 2306 2834 3027 3144 3233 1750 2501 2865 3032 3153 3236% time at or below WSE 7% 63% 78% 83% 86% 88% 48% 68% 78% 83% 86% 89%Consecutive Days at or below WSE 64 148 184 203 204 205 117 150 185 204 204 205With Project with Low rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 2 63 140 205 285 0 11 77 144 214 289% time at or below WSE 0% 0% 2% 4% 6% 8% 0% 0% 2% 4% 6% 8%Consecutive Days at or below WSE 0 2 8 12 17 22 0 5 8 12 17 22With Project with Intermediate rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 1 19 40 60 0 0 4 23 42 66% time at or below WSE 0% 0% 0% 1% 1% 2% 0% 0% 0% 1% 1% 2%Consecutive Days at or below WSE 0 0 1 3 3 8 0 0 2 3 3 5With Project with High rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1 1.1 1.2 1.3 1.4 1.5 1 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%Consecutive Days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0

1098
2-9

Table 7 presents estimates of the time in years to permanent inundation for the No Action

Plan and With Project Plan (conditions are nearly the same for both swamp areas). These

estimates do not consider a rate for biomass and mineral sediment accretion. Biomass and

mineral sediment accretion could extend the timeline until permanent inundation.

Table 7 Years to Permanent Inundation

RSLR Case RSLR Year 50 No Action With Project

Low Rate 1.5 feet 14 years 40 years

Intermediate Rate 1.9 feet 12.5 years 31 years

High Rate 3.2 feet 8 years 17 years

Flood Risks

Finally, Taylor Engineering used 1-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year return

period inflow flood hydrographs as the upstream boundary to model potential impacts of

the alternatives on flood conditions. For purposes of flood analysis, the downstream

boundary was set to a constant elevated stage of 2.0 feet North American Vertical Datum

(NAVD)-88 (2006.81). The USACE Hydrologic Engineering Center Hydrologic

Modeling System (HEC-HMS), developed for the Amite River and Tributaries Amite

River Ecosystem Restoration Feasibility Study, computed the inflow hydrographs.

Chapter 5 describes the flood impact analysis and provides the results.

Figures 1 and 2 present stage hydrographs for the 100-year flood event for two swamp

areas, SE-1 and NE-2. The hydrograph plots compare the stages for the No Action Plan

and the With Project Plan. Figure 1 shows that the project increases peak stage in SE-1

by 0.37 foot. Figure 2 indicates that the project does not change the peak stage in storage

area NE-2.

Figures 3 and 4 illustrate the project impact on 100-year flood stages at two channel

locations, Amite River near Old River and ARDC near Amite River. Figures 3 and 4

show that that the project reduces peak stage at the Amite River near Old River by 0.27

foot, and at ARDC near Amite River by 0.49 foot.

Simulations of the 1-, 2-, 5-, 10-, 25-, 50-, 200-, and 500-year storm events show similar

trends in flood impacts: slight increases in stage for the swamp areas and slight decreases

in stage for the Amite River and ARDC.

The qualitative nature of these results is consistent with the increased exchange between

the ARDC and the swamp for the With Project Plan. Results, however, overstate the

magnitude of the With Project impact given the way the model represents the swamp.

During a flood event, flow characteristics in overbanks (swamp) change from off-channel

storage to conveyance.

1099
2-10

The proposed plan features will not restrict flow in the ARDC or in the swamps adjacent

to the ARDC. Therefore there would not be an increase in the risk of flooding within the

study area. Additionally, increased flood risks would not occur for any nearby businesses

and residences as a result of all proposed actions.

1100
2-11

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

1

2

3

4

5

6

7

8

Storage Area: SE-1

Time

Stage (ft)

Legend

Stage - flood wp 100yr

Stage - flood na 100yr

Figure 1 Storage Area SE-1

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

1

2

3

4

5

6

7

8

Storage Area: NE-2

Time

Stage (ft)

Legend

Stage - flood wp 100yr

Stage - flood na 100yr

Figure 2 Storage Area NE-2

1101
2-12

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

0

2

4

6

8

10

12

River: Amite River Reach: 2 RS: 20.727

Time

Stage (ft)

Legend

Stage - flood na 100yr

Stage - flood wp 100yr

Figure 3 Amite River near Old River

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

0

2

4

6

8

10

12

14

16

River: Diversion Reach: 1 RS: 14.656

Time

Stage (ft)

Legend

Stage - flood wp 100yr

Stage - flood na 100yr

Figure 4 ARDC near Amite River

1102
2-13

Conclusions

The results of the analysis show that the proposed new exchange channels can meet the

hydrodynamic objectives of the project. The proposed new exchange channels would

improve the conveyance of ARDC water into the swamp, and allow a more natural

wetting and drying cycle in the swamp. The effect of RSLR would reduce the

improvements in swamp dry periods, with eventual permanent inundation.

The proposed exchange channels may cause a minor increase in peak flood stages in the

swamps near the ARDC, and a minor decrease in peak flood stages in the Amite River

and ARDC. The Amite River Diversion Canal Modification project would not increase

the flood risk.

1103

J. Anthony Cavell, P.L.S., C.Fed.S.

August 12, 2009

11646 Rue Concord  Baton Rouge, LA 70810  (225) 218-4011

Page 1

George W. Hudson, P.E.,

Senior Engineer

Taylor Engineering, Inc.

2133 Silverside Drive, Suite C

Baton Rouge, Louisiana 70808

Dear George:

We have measured and analyzed over 500 points along routes selected by Taylor

Engineering. These points were compared to the vertical values for those locations

according to the Digital Elevation Model that was based on the Louisiana LiDAR.

The topographic information for this survey is referenced to the North American

Vertical Datum of 1988 (NAVD88) and the National Geodetic Datum of 1983

(NAD83). Those along the diversion canal were not able to be compared due to acute

changes in the topography since the LiDAR was taken, leaving over 300 points to

analyze.

The result of our analysis is that the LiDAR based DEM passes at the 0.8 foot level

the National Map Accuracy Standards (NMAS) test for agreement with the vertical

data based on the LSU GULFNet Reference System. Please see the diagram

attached. The mean difference is only 0.01 foot down. I think no adjustment to the

LiDAR DEM is suggested by our measurements along the roadways.

This report will follow in hard-copy form accompanied by digital records on CD or

DVD media.

If I can be of further service, please dont hesitate to call.

Yours truly,

J. Anthony Cavell, P.L.S., C.Fed.S.

Enclosure

1105
J. Anthony Cavell, P.L.S., C.Fed.S.

August 12, 2009

11646 Rue Concord  Baton Rouge, LA 70810  (225) 218-4011

Page 2

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00

Road Height LiDAR Elevation Comparison

Count 318

Average -0.01

Count (.4) 209.00

% <= 0.4 66%

Count (.8) 287.00

% <= 0.8 90%

1106
J. Anthony Cavell, P.L.S., C.Fed.S.

August 12, 2009

11646 Rue Concord  Baton Rouge, LA 70810  (225) 218-4011

Page 3

Top of Water and Staff measurements

m ft

Staff EPA-B -0.131 -0.43

m ft

Staff EPA-RR -0.287 -0.94

CDT Name Northing Easting Elevation m ft

6:49pm PV tow 202587.506 1049067.756 0.131 0.131 0.43

7:36pm H16-tow 196710.137 1054712.238 0.137 0.137 0.45

8:36pm Clio-tow 200718.155 1069887.085 0.139 0.139 0.46

Wednesday

July 15, 2009

Benchmarks measured or set

Point listing

Name Northing Easting Elevation Feature Code

NEWR2.62 190622.470 1049308.163 6.345 mon

ClioTBM 200609.449 1069713.118 11.714 tbm

PV TBM 202595.105 1049025.429 12.827 tbm

H16 TBM 196813.804 1053404.566 15.714 tbm

TBM RR-OS 191629.615 1062314.669 6.555 tbm

TBM SE1-2-OS 191648.860 1061542.706 8.176 tbm

TBMSE1-1 191623.641 1059937.287 7.396 tbm

TBMBridge 191939.941 1056962.321 10.928 tbm

1107



Hydrology and Hydraulics

Final Report

In Support of

Louisiana Coastal Area

Amite River Diversion Canal Modification

Ecosystem Restoration Feasibility Study

Prepared for

Louisiana Office of Coastal Protection and Restoration

450 Laurel Street

Baton Rouge, LA 70804

by

George Hudson, P.E.

Taylor Engineering, Inc.

2133 Silverside Drive, Suite C

Baton Rouge, LA 70808

January 2010

C2009-083

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TABLE OF CONTENTS

LIST OF FIGURES ....................................................................................................................................ii

LIST OF TABLES .....................................................................................................................................iii

1.0 INTRODUCTION ......................................................................................................................... 1

1.1 Study Area.........................................................................................................................1

1.2 Overview of Modeling ......................................................................................................3

2.0 HYDROLOGICAL MODEL DEVELOPMENT AND CALIBRATION ................................ 5

2.1 Model Development and Geometry.................................................................................5

2.2 Key Model Features..........................................................................................................7

2.3 Model Boundary Conditions............................................................................................7

2.4 Model Calibration Data.................................................................................................. 10

2.5 Calibration Results ......................................................................................................... 10

3.0 SIMULATION OF ALTERNATIVE PLANS .......................................................................... 15

3.1 General............................................................................................................................. 15

3.2 Conceptual Design of Alternatives ................................................................................ 15

3.3 Geometry File Development........................................................................................... 26

3.4 Model Boundary Conditions.......................................................................................... 28

3.5 Model Results .................................................................................................................. 29

4.0 RELATIVE SEA LEVEL RISE ................................................................................................. 31

4.1 General............................................................................................................................. 31

4.2 Estimates of RSLR.......................................................................................................... 31

4.2.1 Low Rate .............................................................................................................. 31

4.2.2 Intermediate and High Rates ............................................................................... 32

4.3 Impact of RSLR .............................................................................................................. 33

5.0 FLOOD RISK .............................................................................................................................. 39

5.1 General............................................................................................................................. 39

5.2 Boundary Conditions...................................................................................................... 39

5.3 Model Results .................................................................................................................. 40

6.0 CONCLUSIONS .......................................................................................................................... 43

REFERENCES.......................................................................................................................................... 44

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LIST OF FIGURES

Figure 1.1 Study Area.............................................................................................................................. 4

Figure 2.1 HEC-RAS Geometry File Calibration Model ........................................................................ 6

Figure 2.2 Location of Gage Stations...................................................................................................... 9

Figure 2.4 HEC-RAS Model and North Swamp at Bridge.................................................................... 13

Figure 2.5 HEC-RAS Model and North Swamp at Railroad................................................................. 14

Figure 3.1 Typical Channel ................................................................................................................... 17

Figure 3.2 Alternative 33....................................................................................................................... 19

Figure 3.3 Alternative 34....................................................................................................................... 20

Figure 3.4 Alternative 35....................................................................................................................... 21

Figure 3.5 Alternative 36....................................................................................................................... 22

Figure 3.6 Alternative 37....................................................................................................................... 23

Figure 3.7 Alternative 38....................................................................................................................... 24

Figure 3.8 Alternative 39....................................................................................................................... 25

Figure 3.9 HEC-RAS Geometry File for with Project Plan .................................................................. 27

Figure 4.1 Plot of Historic Rate from Daily Stage Data........................................................................ 32

Figure 4.2 Plot of Sea Level Rise for Each Case (USACE, 2009, Estimated Sea Level Rise

for Amite River Diversion and Convent/Blind River Diversion LCA Projects).................. 34

Figure 5.1 Storage Area SE-1................................................................................................................ 41

Figure 5.2 Storage Area NE-2 ............................................................................................................... 41

Figure 5.3 Amite River near Old River ................................................................................................. 42

Figure 5.4 ARDC near Amite River...................................................................................................... 42

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LIST OF TABLES

Table 2.1 List of USGS Gages ............................................................................................................... 8

Table 3.1a Computed Flow.................................................................................................................... 29

Table 3.1b Stage Duration, Storage Area SE-1...................................................................................... 30

Table 3.1c Stage Duration, Storage Area NE-2 ..................................................................................... 30

Table 4.1 Summary of Five-year Sea Level Rise for Each Case ......................................................... 33

Table 4.2 Computed Exchange Channel Flows with RSLR ................................................................ 35

Table 4.3 Stage Duration with RSLR, Storage Area SE-1................................................................... 36

Table 4.4 Stage Duration with RSLR, Storage Area NE-2 .................................................................. 37

Table 4.5 Years to Permanent Inundation ............................................................................................ 38

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1.0 INTRODUCTION

The Amite River Diversion Canal Modification Ecosystem Restoration Feasibility Study is being

conducted under the federally authorized Louisiana Coastal Area program (Water Resources

Development Act, 2007), under a cooperative agreement between the U.S. Army Corps of Engineers

(USACE) and the Louisiana Office of Coastal Protection and Restoration (OCPR, formerly Louisiana

Department of Natural Resources, Office of Coastal Restoration). OCPR contracted with Taylor

Engineering to develop a one-dimensional hydrodynamic model to evaluate existing conditions (No

Action Plan) and proposed restoration alternatives (With Project Plan) for the feasibility study (FS).

Taylor Engineering worked as part of a Project Delivery Team (PDT) comprised of project managers,

scientists, engineers from the OCPR and USACE, local university experts on the Maurepas Swamp, and

representatives of the FS lead contractor, GEC, Inc. Taylor Engineering collected field and survey

information in support of the analysis with help from Environmental Coastal and Safety Inc. and Anthony

Cavell, P.L.S.

The restoration alternatives developed by the PDT consist of proposed openings in the elevated

man-made banks of the Amite River Diversion Canal (ARDC). The hydrodynamic model quantifies the

exchange between the ARDC and the adjacent bald cypress-tupelo swamp for existing and alternative

conditions, together with estimates of anticipated stage duration over a 10-year period. Model results

should facilitate further assessment of ecological impacts of alternative plans.

1.1 Study Area

Figure 1.1 (prepared by GEC) shows the limits of the 36 square-mile study area, which lies within

the regional western Maurepas Swamp. The study area contains approximately 19,000 acres of subsiding,

degraded bald cypress tupelo swamp. In 1963, the USACE constructed the ARDC  a 10.6-mile-long

man-made channel  to divert excess flood water from Amite River to Blind River. Blind River

discharges into Lake Maurepas approximately 4.8 miles downstream from its confluence with the ARDC.

Made from ARDC excavated material at the time of construction, the elevated banks on both sides of the

ARDC disrupt the natural hydrologic regime.

The topographic data (based on LIDAR) shows the natural ground elevation in the study area

ranges from 1 to 3 feet NAVD-88. [A check of the LIDAR elevation in the study area indicated that for

purposes of this study, the LIDAR is compatible with other elevation references to the current vertical

datum, NAVD-88 (2006.81).] The natural elevation of the swamp sits just above the mean high water

level of Lake Maurepas, 1.0 feet NAVD-88 (2006.81). Some very mild rises, one or two feet above the

1117
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swamp floor, are present. The overall study area has a mild topographic slope to the south and southeast.

The larger channels, such as the Amite River, Blind River, Old River, Bayou Chene Blanc, and Petite

Amite River, have typically created their own, very low natural banks, only about one to three feet above

the swamp. Exchange via numerous small, shallow sloughs that penetrate the natural low banks

dominates the natural exchange between the larger channels and the swamp.

A major regional river, the Amite River drains the Baton Rouge metropolitan area. Its watershed,

which extends northward into southwestern Mississippi, encompasses an area of over 1,800 square miles.

Lake Maurepas, a coastal water body enclosing over 90 square miles, connects to the Gulf of Mexico via

Pass Manchac and Lake Pontchartrain. Lake Maurepas is subject to coastal astronomical and

meteorological tides.

The study area and regional swamps are the product of geologically recent Holocene alluvial

deposition. Post-glacial rising sea levels, and associated drowning of the lower Mississippi River valley

over the last 10,000 years, have created and reworked the vast coastal deltas and river floodplains of

southeast Louisiana. Similar processes, at a much smaller scale, occurred at the mouth of the Amite River.

The combination of Mississippi River and Amite River depositional processes formed and sustained the

western Maurepas Swamp before human intervention. Modification of regional hydrology over the last

two centuries has substantially reduced the natural nourishment of the swamp, prevented mineral

sediment introduction, and impaired vegetation productivity and the generation and maintenance of

organic substrate. One major aspect of the swamp degradation has been the inability of the ground level to

keep pace with the natural subsidence of the fine, poorly consolidated deltaic and alluvial sediments.

The inflow hydrograph from Amite River and stages in Lake Maurepas influence present-day

stage, discharge, and the duration of flood and dry conditions in the study area. A recent Amite River

flood event occurred with heavy rainfall in the upper watersheds during Tropical Storm Allison in 2001.

This river-dominated flood raised swamp water surface elevations (WSE) to over 4 feet NAVD-88.

Hurricanes Rita in 2004 and Ike in 2008 both produced high stages in Lake Maurepas on the order of 5

feet NAVD-88. Hurricane Juan in 1985 produced even higher stages in Lake Maurepas. Low stages occur

in the Amite River and Lake Maurepas sporadically between the late spring and fall. When low flows in

the Amite River basin combine with extended periods of northerly winds, the stage in Lake Maurepas

drops and causes substantial drainage of the swamps.

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1.2 Overview of Modeling

Taylor Engineering used the USACE Hydrologic Engineering Center River Analysis System

(HEC-RAS) program to model study area flow and stages. The HEC-RAS unsteady state routine

simulates channels and adjacent floodplain swamps as a one-dimensional hydrodynamic system. The

model treats the swamp adjacent to the ARDC as a storage area. HEC-RAS uses Modified Plus or level

pool routing to simulate a storage area. HEC-RAS does not simulate two-dimensional flow patterns in the

swamp. Taylor Engineering used U. S. Geological Survey (USGS) stream gage data for the upstream

boundary condition (inflow hydrograph) and for the downstream boundary condition (stage hydrograph).

Chapter 2 describes the development of the HEC-RAS model, calibrated with 2005 data from two OCPR

swamp gages.

To simulate the No Action Plan and the ARDC modification, Taylor Engineering conducted longterm hydrologic simulations of the study area based on average daily discharge and daily stages for the

10-year period from January 1, 1999 to December 31, 2008. Extracted estimates of flood and drying days

established the current or baseline conditions needed to evaluate the proposed alternatives. Chapter 3

describes the HEC-RAS modeling for the No Action Plan and the With Project Plan, which represented

seven different alternatives, and presents the results.

Taylor Engineering evaluated the potential hydrologic impact on the No Action Plan and the

modification alternatives for estimates of relative sea level rise (RSLR) in accordance with guidance

provided by the USACE, New Orleans District. Chapter 4 describes the analysis of RSLR effects on the

alternative plans and provides the results.

Finally, Taylor Engineering used 1-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year return period

inflow flood hydrographs as the upstream boundary to model potential impacts of the alternatives on

flood conditions. For purposes of flood analysis, the downstream boundary was set to a constant elevated

stage of 2.0 feet NAVD-88 (2006.81). The USACE Hydrologic Engineering Center Hydrologic Modeling

System (HEC-HMS), developed for the Amite River and Tributaries Amite River Ecosystem Restoration

Feasibility Study, computed the inflow hydrographs.. Chapter 5 describes the flood impact analysis and

provides the results.

Chapter 6 presents conclusions from the hydrologic and hydraulic analysis of the ARDC

modification alternatives.

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Figure 1.1 Study Area

4

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5

2.0 HYDROLOGICAL MODEL DEVELOPMENT AND CALIBRATION

2.1 Model Development and Geometry

The HEC-RAS one-dimensional model simulates daily flows and stages in the study area,

including the exchange between major channels and the surrounding swamp. A review of the OCPR gage

data for 2005 shows the model had to simulate the hydrological conditions from stage as low as -1.0 feet

NGVD to a high as 5.0 feet NGVD. In order to simulate these conditions, the model geometry

incorporated eight major river reaches and six major swamp storage areas. Streams and storage areas in

the HEC-RAS geometry file for the current conditions (calibration model) include

Amite River, from upstream of the ARDC to Lake Maurepas

Amite River Diversion Canal, from its confluence with Amite River to Blind River

Blind River, from the Petite Amite River to Lake Maurepas

Petite Amite River, from the ARDC to Blind River

Petite Amite River, north of the ARDC to storage area NW-2

Old River, from Amite River to Chinquapin Canal

Chinquapin Canal, from Old River to Bayou Chene Blanc

Bayou Chene Blanc, from Chinquapin Canal to Blind River

Storage areas North West 2 (NW-2), North East 1 (NE-1), North East 2 (NE-2) South

West 2 (SW-2), South East 1 (SE-1), and South East 2 (SE-2)

Natural ridges, man-made features such as an abandoned railroad embankment and the ARDC

banks, and streams that provide a source of water during high stages or high flow provided fixed points to

delineate storage areas. Lateral structures, culverts, and connections in the model simulate flow into and

out of the storage areas.

Figure 2.1 presents the HEC-RAS geometry file for the calibration model.

1121
Figure 2.1 HEC-RAS Geometry File Calibration Model

6

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7

2.2 Key Model Features

Storage areas and hydraulic connections were used to simulate flow and stages in the swamp.

HEC-RAS uses Modified Plus or level pool routing to compute stages in a storage area. A onedimensional model, HEC-RAS does not simulate flow circulation within the swamp.

Generally, the exchange between the study area channels (the ARDC, rivers, bayous, and

sloughs) and the swamp remains very slow at low stages and increases significantly at high stages. Banks

associated with natural streams and areas of sediment deposition, with elevations ranging from 1.2 to 3

feet, contain the swamp storage areas. For low flow conditions, culverts (and associated equations)

maintain continuity of flow and stabilize the unsteady state simulation. For high stage overbank flow

conditions between the channels and the swamp, weir features (and associated equations) perform a

similar function. Weirs represent high stage conveyance at lateral structures, storage area connections,

and road embankments. Model calibration entailed adjusting weir lengths and weir elevations to obtain a

best fit when comparing the model output to the observed stage data.

2.3 Model Boundary Conditions

The following mean daily stage data (2005) from two USGS gages provided the upstream and

downstream boundary conditions for model calibration.

Amite River at Port Vincent, Louisiana. The mean daily discharge data for this gage

represents the upstream inflow boundary condition.

Amite River at Highway 22 near Maurepas, Louisiana. The mean daily stage for this gage

represents the downstream stage boundary conditions, i.e., the stage in Lake Maurepas.

Taylor Engineering arranged for surveying of the USGS gages and adjusted the stage data to

NAVD-88 (2006.81). Table 2.1 lists information for these two regional USGS gage stations, together

with a third gage at French Settlement. Figure 2.2 shows the locations of the three USGS gages. Figure

2.3 includes hydrographs for the USGS gages adjusted to NAVD-88 (2006.81).

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Table 2.1 List of USGS Gages

Station No. Station Name Data Dates Peak Stage*

7380120 Amite River at

Port Vincent Flow and stage 10/1984 to present

12.73 ft NGVD-29, June

11, 2001; 14.65 ft NGVD29, April 9, 1983 obtained

from observation

07380200

Amite River

near

French

Settlement

Stage 1950  1992

1996 to present

7.40 ft NGVD-29, April 29,

1977

07380215

Amite River at

Hwy 22

near Maurepas

Stage 1998 to present 5.40 ft NAVD-88, August

13, 2008

1124
Figure 2.2 Location of Gage Stations

9

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2.4 Model Calibration Data

Taylor Engineering used data from two swamp gages installed and operated by OCPR in 2005, to

calibrate model parameters. The gage labeled North Swamp at Bridge  located near the bridge over

the Petite Amite River, north of the ARDC  represents a swamp area with good hydraulic connection to

the ARDC. The gage labeled North Swamp at Railroad  located near an abandon railroad

embankment, north of the ARDC  represents an area with no connection to the ARDC. Figure 2.2

(above) shows the locations of the OCPR gages North Swamp at Bridge and North Swamp at Railroad.

At the time of installation, OCPR and USEPA placed staff gages at each station with the

continuous recording gages referenced to the zero level on the staff gage. Taylor Engineering inspected

the gage locations in 2009, including staff gages at the North Swamp at Bridge and North Swamp at

Railroad, and arranged for surveying the two swamp staff gages in order to adjust the stage records to

NAVD-88 (2006.81). OCPR provided the continuous stage data for the gages from January 21, 2005

through December 1, 2005 and Taylor Engineering corrected the data to NAVD-88 (2006.81). Figure 2.3

includes the 2005 stage data for the two OCPR swamp gages, adjusted to NAVD-88 (2006.81).

The Amite River gages show low stages for several weeks during a dry period in May 2005. Both

OCPR swamp gages  North Swamp at Railroad and North Swamp at Bridge  show stages below the

typical natural ground elevations, 1.0 to 1.2 feet NAVD-88 (2006.81), during the period. The gages

allowed for water level measurements below the local ground surface. The swamp gages show that

surface water levels for this period reflect substantial draining of free standing water from the swamp and

the influence of shallow groundwater elevations.

Taylor Engineering used the mean daily stage for the third regional USGS gage, Amite River near

French Settlement, as part of an overall evaluation of model performance.

2.5 Calibration Results

From the above model geometry and boundary conditions, the HEC-RAS model simulated the

January 21, 2005 through December 1, 2005 period. HEC-RAS computed flows and stages at each cross

section and for each storage areas. Figures 2.4 and 2.5 present comparisons of the observed and computed

stages for North Swamp at Bridge and the North Swamp at Railroad. Calibration results show the

following:

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The model cannot simulate below grade (groundwater) swamp WSE in May 2005.

The model produces slightly higher average (0.12 foot) WSE for the North Swamp at

Bridge than the observed data.

The model produces slightly higher average (0.01 foot) WSE for the North Swamp at

Railroad than the observed data.

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Figure 2.3 Stage Data NAVD-88 (2006.81)

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Figure 2.4 HEC-RAS Model and North Swamp at Bridge

13

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Figure 2.5 HEC-RAS Model and North Swamp at Railroad

14

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3.0 SIMULATION OF ALTERNATIVE PLANS

3.1 General

The PDT developed conceptual alternatives to restore the hydrologic exchange between the

ARDC and adjacent swamp in accordance with the federal authorization for the project and previous

preliminary reconnaissance-level studies (GEC, 2008) The basic objective of the alternatives is to

improve the hydraulic connection between the ARDC and the surrounding swamp, and thereby improve

the swamp habit. The improved hydraulic connection should enhance inflow from the ARDC into the

swamp and associated enrichment of swamp nutrients and sediments. The improved connection should

also facilitate swamp drainage during periods of low flow and stages on the ARDC and Lake Maurepas,

and thereby extend dry periods necessary for vegetation productivity.

3.2 Conceptual Design of Alternatives

The PDT conducted field investigations, held meetings, and discussed the nature and functioning

of existing sloughs that control the present hydraulic exchange between major channels and the swamp.

The characteristics of the existing sloughs provide a reasonable guide for the hydraulic design of new,

self-sustaining channels. The proposed exchange channels should ideally mimic natural slough

conveyance and the discharge from the swamps during periods of low flow and low stages.

Several natural sloughs surveyed during the field investigation provide the geometry of typical

self-sustaining exchange channels, including the cross-sectional area (width and depth of opening) and

length into the swamp. A comparison of the bathymetry of these natural sloughs with the size of the

swamp area they appeared to drain  based on LIDAR data  helped to develop the following template

for the proposed exchange channels:

Beginning at the ARDC, a 20-foot bottom width opening

Invert elevation of -5 feet NAVD-88 (2006.81)

Top width of approximately 70 feet

3 horizontal to 1 vertical side slopes throughout

Length from ARDC up into swamp of several thousand feet

Tapering to a cross section with a 10-foot bottom width at the upper end of the channel

Minimum invert elevation of -1 foot NAVD-88 (2006.81) in the upper channel

Minimum top width of approximately 30 feet in the upper channel

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Figure 3.1 illustrates the design for a proposed new exchange channel.

The PDT identified five locations for the new exchange channels based on degraded swamp areas

that are converting to marsh, as well as other design constraints such as the existing residential

development near the ARDC. Located within two storage areas, SE-1 and NE-2, the five proposed

exchange channels include SE-1-1, SE-1-2, NE-2-1, NE-2-2, and NE-2-3.

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Figure 3.1 Typical Channel

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18

The PDT then developed the seven alternatives in the list below. Each alternative represents

selected combinations of the five channel locations and the benefit areas. Figures 3.2 through 3.8

(prepared by GEC) present the plan features and show the locations of the proposed exchange channels.

Alternative 33: on the north side of the ARDC, three exchange channels (NE-2-1, NE-2-

2, and NE-2-3) extending into storage area NE-2

Alternative 34: on the south side of the ARDC, a single exchange channel (SE-1-2)

extending into storage area SE-1

Alternative 35: on the south side of the ARDC and west of Alternative 34, a single

exchange channel (SE-1-1) extending into storage area SE-1

Alternative 36: four exchange channels that combine Alternative 33 and Alternative 34

Alternative 37: two exchange channels that combine Alternative 34 and Alternative 35

Alternative 38: four proposed exchange channels that combine Alternative 33 and

Alternative 35

Alternative 39: five exchange channels that combine Alternative 33 and Alternative 37

1134
Figure 3.2 Alternative 33

19

1135
Figure 3.3 Alternative 34

20

1136
Figure 3.4 Alternative 35

21

1137
Figure 3.5 Alternative 36

22

1138
Figure 3.6 Alternative 37

23

1139
Figure 3.7 Alternative 38

25

1140
Figure 3.8 Alternative 39

25

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3.3 Geometry File Development

Taylor Engineering developed HEC-RAS geometry files for the No Action Plan and With Project

Plan. The geometry of the No Action Plan reflects the existing channels and storage area conditions, as

represented in the previously described geometry for the calibration model. The model of the No Action

Plan provides base-line conditions for comparison to the alternative plans.

Several factors contributed to the creation of the With Plan geometry file. First, the flow volume

and the flow rate through each of the five individual exchange channels is insignificant compared to the

total volume, discharge, and the stage in the ARDC. Second, the hydraulic performance of each proposed

exchange channel is independent of the others. As such, the With Project geometry file includes all five

exchange channels used to analyze the seven alternatives. In the single With Project geometry file, Taylor

Engineering slightly increased the size of storage areas NE-2 and SE-1, and correspondingly decreased

the size of storage areas NE-1 and SE-2, to capture some of the impact of the proposed degradation of the

railroad embankments. Figure 3.9 illustrates the With Project Plan geometry file.

The HEC-RAS geometry file for the With Project Plan represents each proposed exchange

channel from the intersection of the ARDC; each exchange channel extends into the swamp for several

hundred feet, with cross-sectional dimensions as described above. As with the existing conditions (No

Action Plan) model, a road embankment and a culvert crossing the exchange channel represent flow

control between the ARDC and the swamp storage area in the new exchange channels. The road

embankment and culvert allow simulation of the exchange of flow between the channel and the swamp

under both high flow (overbank flow) and low flow (normal conditions).

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Figure 3.9 HEC-RAS Geometry File for with Project Plan

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3.4 Model Boundary Conditions

The hydrological analysis of the No Action Plan and the With Project Plan must consider the

possible effects of three other federal projects authorized for construction within the Amite River and the

Blind River Watersheds. These three projects include two feasibility studies  the LCA Small Diversion

at Convent/Blind River and the LCA Small Diversion at Hope Canal  and a flood risk reduction project

 the Amite River and Tributaries (AR&T), Comite River Diversion Canal  currently under

construction.

Given the control exerted by the Amite River and Lake Maurepas on study area water levels, the

selection of any particular model boundary condition greatly influences the model results. Therefore,

Taylor Engineering recommended evaluating the No Action Plan and the restoration alternatives by

simulating conditions over a very long timeframe, and assessing the impact to episodic flood and dry

conditions in the swamp storage areas. Based on data availability for the upstream (Amite River at Port

Vincent) and downstream (Amite River at Maurepas) boundary conditions, Taylor Engineering selected

the historical 10-year period of January 1, 1999 to December 31, 2008.

Upstream boundary conditions incorporate the inflow hydrographs from the Blind River

Diversion Project and the Hope Canal Diversion Project. The combined inflow hydrographs for the Blind

River and the Hope Canal diversions were input into the HEC-RAS model at the confluence of Petite

Amite River and Blind River. The LCA Small Diversion at Convent/Blind River and the LCA Small

Diversion at Hope Canal projects are currently a feasibility study and the hydraulic design and operating

plans have not been determined. The USACE, New Orleans District provided hydraulic design

information concerning the design flows and the operating plans. The following summarizes the hydraulic

design for the Blind River Diversion and the Hope Canal Diversion projects:

LCA Small Diversion at Convent/Blind River

Design discharge (January through May)  1000 to 2500 cubic feet per second (cfs) with

1500 cfs estimated as a good planning discharge rate

Design discharge (June through November)  500 cfs

Diversion flows pulsed 15 days with and 15 days without flow

LCA Small Diversion at Hope Canal

Design discharge (January through May)  2000 cfs

Design discharge (June through November)  500 to 1500 cfs

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Diversion flows pulsed 10 days with and 20 days without flow

Approximately 50% of the flow diverted to Blind River

The combined inflow hydrograph for the diversion flows from the Blind River and the Hope

Canal diversion projects totals 3,000 cfs (January through May) and 1,500 cfs (June through November).

Taylor Engineering also incorporated the Comite River Diversion Canal project in the Amite

River inflow boundary. The Comite River Diversion Canal is designed to divert approximately 50% of

the Comite River flow during a flood event. (The Comite River enters the Amite River in Denham

Springs, Louisiana, well above the study area.) During low flow periods (flows less than approximately

1,200 cfs), no flow is diverted out of the Comite River. Results from the existing HEC-HMS and HECRAS models for the Amite River basin indicate that the Comite River Diversion Canal will reduce flow

on the Amite River by approximately 7% during flood events. Taylor Engineering therefore adjusted the

Amite River at Port Vincent boundary inflow downward by 7% for flood events.

3.5 Model Results

Tables 3.1 present model results for the No Action Plan and the With Project Plan. Table 3.1a

presents a summary of the computed flows in the exchange channels. Table 3.1b and 3.1c present a

comparison of stage duration (in days) in swamp storage areas SE-1 and NE-2. Table 3.1b combines

results for the two exchange channels in this area. Table 3.1b shows that the With Project Plan increases

the percentage of days in SE-1 with WSE at or below 1.0 foot from 6 to 37%. Table 3.1c shows the With

Project Plan increases the number of days with WSE at or below 1.0 foot from 7 to 48% in NE-2.

Table 3.1a Computed Flow

With Project (no flow in the No Action Plan)

Exchange Channel SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 6330 5298 4812 4368 4035

% time of inflow 23% 22% 29% 28% 28%

Volume outflow (ac-ft/yr) 6874 7160 3392 3696 4088

% time of outflow 77% 78% 71% 72% 72%

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Table 3.1b Stage Duration, Storage Area SE-1

No Action

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 213 2283 2742 2935 3059 3151

% time at or below WSE 6% 62% 75% 80% 84% 86%

Consecutive Days at or below WSE 73 120 138 164 203 204

With Project

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 1352 2390 2770 2950 3070 3160

% time at or below WSE 37% 65% 76% 81% 84% 86%

Consecutive Days at or below WSE 114 121 152 164 203 205

Table 3.1c Stage Duration, Storage Area NE-2

No Action

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 241 2306 2834 3027 3144 3233

% time at or below WSE 7% 63% 78% 83% 86% 88%

Consecutive Days at or below WSE 64 148 184 203 204 205

With Project

Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5

Total Days in Simulation 3654 3654 3654 3654 3654 3654

Total days at or below WSE 1750 2501 2865 3032 3153 3236

% time at or below WSE 48% 68% 78% 83% 86% 89%

Consecutive Days at or below WSE 117 150 185 204 204 205

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31

4.0 RELATIVE SEA LEVEL RISE

4.1 General

Given the hydrologic influence of tidal Lake Maurepas and the regional subsidence conditions,

relative sea level rise (RSLR) could affect the computed flows in the proposed exchange channels and the

stage durations shown in Tables 3.1. In response to this concern, the PDT evaluated the potential impact

of RSLR on the restoration alternative. The evaluation adhered to guidelines established in Incorporating

Sea Level Change Considerations in Civil Works Programs, EC 1165-2-211, (USACE, 2009a).

4.2 Estimates of RSLR

The USACE guidance requires an assessment of project performance based on three estimates

(low, intermediate, and high) of sea level rise. The low estimate reflects the local historic rate for the

study area, based on long-term local gage data. The intermediate and high estimates reflect a combination

of the local historic subsidence rate with either the modified NRC Curve I or the NRC Curve III estimate

of eustatic sea level rise.

The USACE, New Orleans District prepared RSLR estimates in accordance with EC 1165-2-211

for LCA projects Amite River Diversion Canal and Convent/Blind River Diversion (USACE, 2009b).

These estimates of RSLR account for both the eustatic rate of sea level rise and the local subsidence rate.

The following paragraphs summarize the USACEs documentation of those estimates.

4.2.1 Low Rate

The USACE used the USACE gage at West End at Lake Pontchartrain to calculate a

representative historic rate for the project area. Daily stage data from 1959 to 2009 indicate a rate of 9.20

mm/yr (0.0302 ft/yr; see Figure 4.1) with a standard error of the linear trend line of 0.65 foot.

1147
32

West End at Lake Pontchartrain (85625) Historical Stage Data y = 0.0302x - 57.963

-2

-1

0

1

2

3

4

5

6

7

8

1956195719581959196019611962196319641965196619671968196919701971197219731974197519761977197819791980198119821983198419851986198719881989199019911992199319941995199619971998199920002001200220032004200520062007200820092010201120122013

Stage (feet)

Figure 4.1 Plot of Historic Rate from Daily Stage Data

Using the rate of 9.20 mm/yr, a starting year of 2012, and a 50-year project life, the USACE

projects a sea-level rise of 1.5 feet for 2062. The rate of 9.20 mm/yr includes both the eustatic seal level

rise and the local subsidence contributions to the estimated total RSLR.

4.2.2 Intermediate and High Rates

To estimate the local subsidence rate for the project area, the USACE subtracted the global

eustatic rate (1.7 mm/yr) from the local sea level rate or

Local subsidence rate = 9.20 mm/yr  1.7 mm/yr = 7.50 mm/yr.

The following formula yields an estimate of the total rise in eustatic sea level for the project life

for the intermediate and high rate cases of sea level rise:

)()(0017.0)()(

2

1

2

2 1 12 2 tEtE   ttbtt

where:

b = the acceleration factor for each curves, or 2.36E-5 and 1.005E-4, respectively,

t1 = the time in years between the projects construction date and 1986, and

t2 = the time between a future date at which one wants an estimate for sea-level rise and 1986.

These eustatic estimates, when added to the local subsidence estimate, yield the total sea-level

rise for the intermediate and high rate cases.

Table 4.1 presents a summary of the estimated total sea-level rise in five-year increments through

the project life of 50-years for each case. Figure 4.2 shows the estimated sea-level rise for each case.

1148
33

Table 4.1 Summary of Five-year Sea Level Rise for Each Case (USACE, 2009, Estimated Sea Level Rise

for Amite River Diversion and Convent/Blind River Diversion LCA Projects)

Project year Low Rate

(feet)

Intermediate Rate

(feet)

High Rate

(feet)

2012 0.0 0.0 0.0

2017 0.2 0.2 0.2

2022 0.3 0.3 0.5

2027 0.5 0.5 0.8

2032 0.6 0.7 1.1

2037 0.8 0.9 1.4

2042 0.9 1.1 1.7

2047 1.1 1.3 2.0

2052 1.2 1.5 2.4

2057 1.4 1.7 2.8

2062 1.5 1.9 3.2

4.3 Impact of RSLR

Taylor Engineering reran the HEC-RAS models for the No Action Plan and the With Project Plan

for 2062 (Year-50) for the three RLSR cases by adding 1.5, 1.9, and 3.2 feet to the Amite River at

Maurepas hydrograph downstream boundary condition. Tables 4.2, 4.3, and 4.4 presents model results.

Table 4.2 includes the previous results (Year 1) for computed flows in the exchange channels versus

computed Year 50 flows for low, intermediate, and high RSLR. Tables 4.3 and 4.4 provide similar

comparisons of stage durations for the previously computed Year 1 versus Year 50 low, intermediate, and

high RSLR for the No Action Plan and With Project Plan in SE-1 and NE-2, respectively.

Table 4.2 demonstrates that as stages increase in Lake Maurepas due to RSLR, the flow in the

proposed new exchange channels increase.

Tables 4.3 and 4.4 show that RSLR will dramatically reduce the stage duration below 1.0 foot

with both the No Action Plan and the With Project Plan. The percentage of days with WSE below 1.0 foot

in the SE-1 and NE-2 areas falls from 37 and 48%, respectively, to zero under all three RSLR cases.

1149
34

Estimated Sea Level Rise for Amite River Diversion and

Convent/Blind River Diversion LCA Projects IAW EC-1165-2-211

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

2000 2010 2020 2030 2040 2050 2060 2070

Year

Estimated Sea Level Rise (feet)

Low curve (historic) Intermediate curve High curve

Figure 4.2 Plot of Sea Level Rise for Each Case (USACE, 2009, Estimated Sea Level Rise for Amite

River Diversion and Convent/Blind River Diversion LCA Projects)

1150
35

Table 4.2 Computed Exchange Channel Flows with RSLR

With project with no RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 6330 5298 4812 4368 4035

% time of inflow 23% 22% 29% 28% 28%

Volume outflow (ac-ft/yr) 6874 7160 3392 3696 4088

% time of outflow 77% 78% 71% 72% 72%

With Project with 50 years of Low rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 23175 20734 14522 13503 12903

% time of inflow 35% 34% 54% 53% 52%

Volume outflow (ac-ft/yr) 32635 35202 7291 8187 8894

% time of outflow 65% 66% 46% 47% 48%

With Project with 50 years of Intermediate rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 28332 25659 15172 14131 13480

% time of inflow 36% 35% 56% 55% 54%

Volume outflow (ac-ft/yr) 41868 45382 7324 8397 9234

% time of outflow 64% 65% 44% 45% 46%

With Project with 50 years of High rate of RSLR

Reach (cut) SE1-1 SE1-2 NE2-1 NE2-2 NE2-3

Storage area SE-1 SE-1 NE-2 NE-2 NE-2

Volume Inflow (ac-ft/yr) 36013 33138 15622 14617 14028

% time of inflow 39% 38% 56% 54% 52%

Volume outflow (ac-ft/yr) 57802 63338 74145 9374 11222

% time of outflow 61% 62% 44% 46% 48%

1151
Table 4.3 Stage Duration with RSLR, Storage Area SE-1

No Action Plan With Project Plan

Without RSLRWater Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 213 2283 2742 2935 3059 3151 1352 2390 2770 2950 3070 3160% time at or below WSE 6% 62% 75% 80% 84% 86% 37% 65% 76% 81% 84% 86%Consecutive Days at or below WSE 73 120 138 164 203 204 114 121 152 164 203 205With Project with Low rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 15 60 89 120 0 8 62 104 162 206% time at or below WSE 0% 0% 0% 2% 2% 3% 0% 0% 2% 3% 4% 6%Consecutive Days at or below WSE 0 0 2 7 9 12 0 2 7 10 16 22With Project with Intermediate rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 3 7 0 0 3 12 24 38% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1% 1%Consecutive Days at or below WSE 0 0 0 0 1 2 0 0 1 3 3 3With Project with High rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%Consecutive Days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0

36

1152
Table 4.4 Stage Duration with RSLR, Storage Area NE-2

No Action Plan With Project Plan

Without RSLRWater Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 241 2306 2834 3027 3144 3233 1750 2501 2865 3032 3153 3236% time at or below WSE 7% 63% 78% 83% 86% 88% 48% 68% 78% 83% 86% 89%Consecutive Days at or below WSE 64 148 184 203 204 205 117 150 185 204 204 205With Project with Low rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 2 63 140 205 285 0 11 77 144 214 289% time at or below WSE 0% 0% 2% 4% 6% 8% 0% 0% 2% 4% 6% 8%Consecutive Days at or below WSE 0 2 8 12 17 22 0 5 8 12 17 22With Project with Intermediate rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 1 19 40 60 0 0 4 23 42 66% time at or below WSE 0% 0% 0% 1% 1% 2% 0% 0% 0% 1% 1% 2%Consecutive Days at or below WSE 0 0 1 3 3 8 0 0 2 3 3 5With Project with High rate of RSLR (50 years)Water Surface Elevation (WSE) feet 1.0 1.1 1.2 1.3 1.4 1.5 1.0 1.1 1.2 1.3 1.4 1.5Total Days in Simulation 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654 3654Total days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0% time at or below WSE 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%Consecutive Days at or below WSE 0 0 0 0 0 0 0 0 0 0 0 0

37

1153
38

Table 4.5 presents estimates of the time in years to permanent inundation for the No Action Plan

and With Project Plan (conditions are nearly the same for both swamp areas). These estimates do not

consider a rate for biomass and mineral sediment accretion. Biomass and mineral sediment accretion

could extend the timeline until permanent inundation.

Table 4.5 Years to Permanent Inundation

RSLR Case RSLR Year 50 No Action With Project

Low Rate 1.5 feet 14 years 40 years

Intermediate Rate 1.9 feet 12.5 years 31 years

High Rate 3.2 feet 8 years 17 years

1154
39

5.0 FLOOD RISK

5.1 General

Flooding problems in the study area are primarily associated with high discharges and stages on

the Amite River. (Back- water flooding can affect the study area due to high coastal storm driven stages

on Lake Maurepas.) FEMA Flood Insurance Rate Maps show that study area Base Flood Elevations

(BFE) range from 6 to 9 feet NAVD-88.

Taylor Engineering used the HEC-RAS geometry models described in Chapter 3 to assess

potential impacts to current flood risk in the study area by comparing flood stages for the No Action Plan

versus With Project Plan. The HEC-RAS models of the study area simulate the swamps as storage areas

and connect the storage area to the ARDC with the proposed exchange channels. These models simulate

the flow into and out of the swamp (storage area) under low-to-normal flow and stage conditions. During

a major flood event, flow characteristics change from off channel storage to conveyance. This model does

not treat the swamp areas as conveyance features.

5.2 Boundary Conditions

To analyze flood impacts, Taylor Engineering developed flow hydrographs for nine return period

storms (1-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year), each with seven-day duration. U.S. Weather

Bureau Technical Paper No. 40 (TP-40) and National Weather Service HYDRO-35 provided values of

rainfall intensity and duration. HEC-HMS and HEC-RAS models of the Amite River watershed (Taylor

Engineering, 2009) were used to compute the inflow hydrographs. The inflow hydrographs used for the

upstream boundary conditions were computed upstream of the ARDC. Local inflow hydrographs from

within the study area (36 square miles) are insignificant compared to the peak discharge and runoff

volume from the Amite River watershed upstream of the ARDC (1,769 square miles). This insignificance

precluded the need to factor in local runoff inflows.

As with other simulations, Taylor Engineering used Lake Maurepas as the downstream boundary,

and employed an elevated, constant stage of 2.0 feet NAVD-88 (2006.81) for the analysis of all storm

events. The average daily stage for the Amite River at Maurepas gage for the 10-year period of January 1,

1999 to December 31, 2008, adjusted to NAVD-88 (2006.81), is 0.76 foot and the mean high water is 1.0

foot.

1155
40

5.3 Model Results

Figures 5.1 and 5.2 present stage hydrographs for the 100-year flood event for two swamp areas,

SE-1 and NE-2. The hydrograph plots compare the stages for the No Action Plan and the With Project

Plan. Figure 5.1 shows that the project increases peak stage in SE-1 by 0.37 foot. Figure 5.2 shows that

the project does not change the peak stage in storage area NE-2.

Figures 5.3 and 5.4 illustrate the project impact on 100-year flood stages at two channel locations,

Amite River near Old River and ARDC near Amite River. Figures 5.3 and 5.4 show that that the project

reduces peak stage at the Amite River near Old River by 0.27 foot, and at ARDC near Amite River by

0.49 foot.

Simulations of the 1-, 2-, 5-, 10-, 25-, 50-, 200-, and 500-year storm events show similar trends in

flood impacts: slight increases in stage for the swamp areas and slight decreases in stage for the Amite

River and ARDC.

The qualitative nature of these results is consistent with the increased exchange between the

ARDC and the swamp for the With Project Plan. Results, however, overstate the magnitude of the With

Project impact given the way the model represents the swamp. During a flood event, flow characteristics

in overbanks (swamp) change from off-channel storage to conveyance. Results show that the proposed

project would not increase the risk of flooding along the Amite River and ARDC.

1156
41

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

1

2

3

4

5

6

7

8

Storage Area: SE-1

Time

Stage (ft)

Legend

Stage - flood wp 100yr

Stage - flood na 100yr

Figure 5.1 Storage Area SE-1

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

1

2

3

4

5

6

7

8

Storage Area: NE-2

Time

Stage (ft)

Legend

Stage - flood wp 100yr

Stage - flood na 100yr

Figure 5.2 Storage Area NE-2

1157
42

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

0

2

4

6

8

10

12

River: Amite River Reach: 2 RS: 20.727

Time

Stage (ft)

Legend

Stage - flood na 100yr

Stage - flood wp 100yr

Figure 5.3 Amite River near Old River

02 03 04 05 06 07 08 09 10 11 12 13 14 15 2/1/2006

0

2

4

6

8

10

12

14

16

River: Diversion Reach: 1 RS: 14.656

Time

Stage (ft)

Legend

Stage - flood wp 100yr

Stage - flood na 100yr

Figure 5.4 ARDC near Amite River

1158
43

6.0 CONCLUSIONS

The results of the analysis show that the proposed new exchange channels can meet the

hydrodynamic objectives of the project. The proposed new exchange channels would improve the

conveyance of ARDC water into the swamp, and allow a more natural wetting and drying cycle in the

swamp. The effect of RSLR would reduce the improvements in swamp dry periods, with eventual

permanent inundation.

The proposed exchange channels may cause a minor increase in peak flood stages in the swamps

near the ARDC, and a minor decrease in peak flood stages in the Amite River and ARDC. The Amite

River Diversion Canal Modifications would not increase the flood risk.

1159
44

REFERENCES

Arcement, G. J. Jr., Schneider, V. R. 1989. Guide for Selecting Mannings Roughness Coefficients for

Natural Channels and Flood Plains, United States Geological Survey, Water-Supply Paper 2339.

Chow, Ven Te. 1959. Open Channel Hydraulics. McGraw-Hill. NY.

Frederick, R.H. 1977. Five to Sixty Minutes Precipitation Frequency for the Eastern and Central United

States, National Oceanic and Atmospheric Administration Technical Memorandum, National

Weather Service, Hydro-35, Soil Conservation Service U.S. Department of Agriculture.

GEC, Inc. 2008. Interim Feasibility Study, Amite River Diversion Canal Modification, Louisiana Coastal

Area (LCA). Baton Rouge, LA.

Herschfield, D.M. 1961. Rainfall Frequency Atlas of the United States for Durations from 30 Minutes to

24 Hours and Return Periods from 1 to 100 Years. Technical Paper No. 40 Weather Bureau, U.S.

Department of Commerce. Washington, D.C,

Taylor Engineering, Inc. 2009. Draft (In progress, not published) HEC-RAS and HEC-HMS Models in

Support of the Amite River Ecosystem Restoration Feasibility Study, an Amite River and

Tributaries Authorized Study for the USACE and Pontchartrain Levee District. Baton Rouge, LA.

U.S. Army Corps of Engineers. 2009a. Incorporating Sea Level Change Considerations in Civil Works

Programs, EC 1165-2-211. Washington, D.C.

U.S. Army Corps of Engineers. 2009b. Estimated Sea Level Rise for Amite River Diversion and

Convent/Blind River Diversion LCA Projects. New Orleans, LA.

U.S. Army Corps of Engineers. 2003. Hydrologic Engineering Center, River Analysis System Users

Manual, Version 4.0. Davis, CA.

1160
Section 3

SURVEY DATA

1161

	

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1163
	

Figure 2. Relict Cut Cross Section Locations

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1164
		

Figure 4. Relict Cut Cross Section C

Figure 5. Relict Cut Cross Section D

1165
	


Figure 6. Relict Cut Cross Section D

Figure 7. Cross Section Locations for Full Survey

1166
	

Figure 8. Cross Section of Dredged Material Berm on South Bank

Figure 9. Cross Sections of Dredged Material Berm on North Bank

1167
	

Figure 10. Relict Cut Cross Sections

1168
ANNEX

Survey Data

1169

1171

1173

1175
1176
1177
1178
1179
1180
1181
1182
1183

1185

1187

1189

1191

1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203

1205

1207

1209

1211

1213

1215

1217

1219

1221

Section 4

GEOLOGY

1223




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1226
Section 5

GEOTECHNICAL

INVESTIGATION

1227



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1230
5-3

Geotechnical Assumption & Criteria

In the process of developing preliminary designs of proposed alternative plans for the Louisiana

Coastal Area Amite River Diversion Canal (LCA ARDC) Modification project, some

geotechnical assumptions were made. First, it was assumed that if the cross sections for the

proposed conveyance channels were to mimic the cross sectional makeup of relict cuts, found

near Blind River, the proposed channels would maintain a hydrologic equilibrium by

maintaining flow rates large enough to prevent the buildup of sediments within the channel over

the lifespan of the project. Secondly, it was assumed that with a 3H:1V slope and seeding and

mulching, the slopes along the dredged material berm openings would remain stable. This is

based on the assumption that the berm material is primarily composed of clay, allowing for

increased slope stability. The existing slopes on the dredged material berm are between 2:1 and

3:1 and have remained stable. Therefore, until a geotechnical investigation can be completed, it

is reasonable to assume that a slope of 3:1 cut into the berm as an opening would remain stable.

Geotechnical Uncertainties

Until a full geotechnical investigation is performed in the PED phase of the project, uncertainties

will exist with the assumptions made regarding material placement and slope stability. It is

assumed that when material from excavation is placed within the project area, it will be stable

enough to create habitat at an elevation sufficient to sustain bottomland hardwood tree species.

However, if the material does not maintain the required elevations, a shift in the tree species to

be utilized for these plantings will be made to those suitable for a freshwater swamp.

Additionally, the stability of channel and placement area slopes will not be known until the full

results of a slope stability analysis are completed.

Planned Geotechnical Investigations

A Scope of Work for a planned geotechnical investigation to support the planning and design of

the LCA ARDC Modification project has been developed. The investigation will be conducted,

during the Preliminary Engineering and Design phase of the project (PED). Investigations will be

performed in accordance with USACE geotechnical investigation standards (EM 1110-1-1804,

Chapter F, paragraphs 6-5 through 6-7). Lab testing will be conducted in accordance with ER

1110-1-8100 and ER 1110-1-261. The Contracting Party’s equipment shall use a fixed-piston

type sampling method (Hvorslev fixed-piston or equivalent). An undisturbed type piston

sampler shall utilize a minimum of 5- inch Shelby Tubes (5" O.D., approx. 4-3/4" I.D.) that are a

minimum of 54 inches in length with sealing caps. The Contractor shall perform global slope

stability analyses, soil classification under the Unified Soil Classification System, as well as

Triaxial Shear and Consolidated Undrained analysis.

Survey for Geotechnical Investigations

In conjunction with the geotechnical investigation, a land survey will be conducted. The survey

will include additional cross sections of the dredged material berm, along with the proposed

conveyance channels. The limits of the cross-sections in the spoil bank should be 200’ from the

center of the proposed cut (for a total cross-section width of 400’). The limits of the crosssections not in the spoil bank should be 100’ from the center of the proposed cut (for a total

cross-section width of 200’). Additional cross-sections will be taken on the spoil bank

1231
5-4

perpendicular to the spoil bank along the centerline of the proposed cuts. The cross section

should be approximately 125’ on either side of the center of the spoil bank (for a total crosssection width of 250’) at the 3 proposed cut locations on the north side of the ARDC and should

show all significant break points of the spoil bank. An additional cross section should be

approximately 300’ on either side of the center of the spoil bank (for a total cross-section width

of 600’) at the proposed eastern-most cut on the south side of the ARDC and should show all

significant break points of the spoil bank. An additional cross section should be approximately

200’ on either side of the center of the existing spoil bank (for a total cross-section width of

400’) at the proposed western-most cut on the south side of the ARDC and should show all

significant break points of the existing spoil bank. All breakpoints between these limits should

be accounted for to ensure that all major elevation changes are incorporated into the crosssection. The Contracting Party shall conduct all surveying activities using three Bench Marks

(TBMs) established by Anthony Cavell utilizing Continually Operating Reference Stations

(CORS) stations and Global Positioning System Real time Kinematic (GPS RTK).

1232
Section 6

CONCEPTUAL DESIGN

ALTERNATIVES EXPLORED

1233

Alternatives Volume II  LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) March 2010 3-1

1 3.0 Alternative 33 (TSP) (NE-1/NE-2)

2

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1235
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 33

Map ID: 27850108-1868

LITTLE BAYOU CHENE BLANC

NE-2

SE-2

NE-3

SE-1

NE-1

Railroad

Grade 956 Acres

Secondary

Impact Area

438 Acres

Proposed

Vegetative

Planting

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

BAYOU

BAYOU CHENE BLANC

BLIND RIVER

AMITE RIVER DIVERSION CANAL

BLANC

CHENE

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

SE-1

Material Berm

Notes:Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 1

1236
Alternatives Volume II  LCA Amite River Diversion Canal Modification

WRDA 2007 Section 7006(e)(3) March 2010 3-3

495051

Table 1. Alternative Quantities 52

53

Footprints (Acres) Excavation (Cubic Yards)*

Berm Swamp

Alternative

Slopes

&

Benches

Channel Channel

10 Gaps

and

Stumps

Material

Placement Total

Dredged

Material

Berm Cut

Channel

Cut Total

** / .E (.E /'.E 5.E 5.( */.4 /*-'5* E/-)02 05-22'*2 4 .5 (.0 0.) *./ 4.' /E.E 4'-E)' 25-E'* '*-'2(*5 / .E (.) ).) 4./ 4.4 /*.* 45-54' *2-02/ )(-2)E*) 2 .* /.' 4'.2 E.E '.E 5(.( 2/-)4( /4'-5)' /)0-/E'*' 2 .* /.5 /).4 5.4 2.0 *4./ 5*-*02 E(-E/2 /*2-4(E*E * .) /.2 42.2 '.0 '.4 22.5 *0-4E( //)-)*5 /55-0/5*0 ) ./ 4.* *2.( //.( 0.0 )*.* )'-/2' /)4-5(E 440-)55

54

F %	  
	 	  	 
	  	. 55

56

1237
Existing Grade (Elev 1.0 ft +/-)

10 ft 17 ft 5 ft

Existing TreesTo Remain

Trees To BePlanted

Existing TreesTo Be Removed

-5.0 Elev

Average WaterLevel (Elev 0.7 ft +/-)

20 Ft

70 ft +/-

25 ft +/- 25 ft +/-

4h to 1v Slope

10 ft 17 ft 5 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to Scale

Source: GEC

Typical 70 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Dimensions

Figure: 2

1238
Existing Grade (Elev 1.0 ft +/-)

10 ft 17 ft 5 ft

Existing TreesTo Remain

Trees To BePlanted

Existing TreesTo Be Removed

-5.0 Elev

Average WaterLevel (Elev 0.7 ft +/-)

20 Ft

70 ft +/-

25 ft +/- 25 ft +/-

4h to 1v Slope

10 ft 17 ft 5 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to Scale

Source: GEC

Typical 70 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Dimensions

Figure: 3

1239
10 ft 12 ft 5 ft

Existing TreesTo Remain

Trees To BePlanted

-3.0 Elev

Existing TreesTo Be Removed

Average WaterLevel (Elev 0.7 ft +/-)

20 ft 15 ft +/- 15 ft +/-

Existing Grade ( Elev 1.0 ft +/-)

50 ft +/-

4h to 1v Slope

10 ft 12 ft 5 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to ScaleSource: GEC

Typical 50 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Figure: 4

1240
10 ft 5 ft 9 ft

Average WaterLevel (Elev 0.7 ft)

-2.0 ft Elev

Existing TreesTo Remain

Trees To BePlanted

Existing TreesTo Be Removed

Existing Grade ( Elev 1.0 ft +/-)

30 ft +/-

10 ft +/-

4h to 1v Slope

10 ft +/- 10 ft 10 ft 5 ft 9 ft

Existing Trees

To Remain

Trees To Be

Planted

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: January 2010Not to ScaleSource: GEC

Typical 30 ft. Cross Section through ARDC Native Swamp

Map ID: 27850108-1741

Legend

Existing GradeDimensionsAverage Water LevelChannel CutDredge Material PlacementStumpsDredge Area

Note: Dredged material to be deposited along theproposed conveyance channel at approximately300 foot intervals with 50 foot gaps included.

Figure: 5

1241
Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana Source: USDA/GEC

Scale:

Date: January 2010

TYPICAL CONVEYANCE CHANNEL

Map ID: 27850108-1889

Amite River Diversion Canal

70' Channel Through Existing

Dredge Material Berm and Swamp:

20' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -5.0' +/-

50' Channel Through Swamp:

20' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -3.0' +/-

30' Channel Through Swamp:

10' Bottom Width

Side Slopes 4 h to 1 v

Invert Elevation -2.0' +/-

1:5,600

0 200 400 600

Feet

Map Extent

NE-1 NE-2

SE-2

SE-1 SW-2

NW-2

Amite River

NE-3

Diversion Canal

Legend

30' Channel

50' Channel

70' Channel

Cut Through Existing Dredge Material Berm

Dredge Material & Stump Placement

Subunits

Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Figure: 6

SE-1

1242
Alternatives Volume II  LCA Amite River Diversion Canal

Modification

EA WRDA 2007 Section 7006(e)(3) 3-9 March 2010

3.4.3 Alternative 34 (SE-1/SE-2)

 	
 
    


  
   
 	

 
 	
 
 	

 

 


 	 
 	
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1243
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 34

Map ID: 27850108-1869

SE-1

SE-2

BLIND RIVER

NE-1

Railroad

Grade

1,033 Acres

Secondary

Impact Area

487 Acres

Proposed

Vegetative

Planting

426 Acres

Primary

Impact Area

Footprint =

18.8 Acres

AMITE RIVER DIVERSION CANAL NE-2

1:24,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm 87 sq. ft. Dredged Material Berm

SE-1

Notes:Footprint acreage equalssum of all Dredged MaterialBerms, Conveyance Channels,and Cuts Through ExistingDredged Material Berms.Spaces between DredgedMaterial Berms are shownlarger than actual size forgraphic purposes.

Figure: 7

1244
Alternatives Volume II  LCA Amite River Diversion Canal

Modification

EA WRDA 2007 Section 7006(e)(3) 3-11 March 2010

3.4.4 Alternative 35 (SE-1)

 	
 
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1245
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: December 2009Scale:Source: USGS/GEC

ALTERNATIVE 35

Map ID: 27850108-1870

SE-1 PETITE AMITE RIVER

NE-1

Railroad

Grade

377 Acres

Secondary

Impact Area

443 Acres

Primary

Impact Area

Footprint =

13.3 Acres

AMITE RIVER DIVERSION CANAL

NE-2

SW-2

SE-2

1:20,000

0 1,000 2,000 3,000

Feet

Map Extent Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade Cuts

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

Notes:Footprint acreage equals sum of all Dredged MaterialBerms, Conveyance Channels, and Cuts ThroughExisting Dredged Material Berms.Spaces between Dredged Material Berms are shownlarger than actual size for graphic purposes.

Figure: 8

1246
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 36

LITTLE BAYOU CHENE BLANC

Map ID: 27850108-1871

SE-1

NE-2 NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER Railroad Grade

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

Footprint =

18.8 Acres

1,033 Acres

Secondary

Impact Area

426 Acres

Primary

Impact Area

487 Acres

Proposed

Vegetative

Planting

SW-2

ALLIGATOR BAYOU

1:40,000

0 2,000 4,000 6,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes:Footprint acreage equals sum of all DredgedMaterial Berms, Conveyance Channels, and CutsThrough Existing Dredged Material Berms.Spaces between Dredged Material Berms areshown larger than actual size for graphic purposes.

Figure: 9

1247
Alternatives Volume II  LCA Amite River Diversion Canal

Modification

EA WRDA 2007 Section 7006(e)(3) 3-14 March 2010

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1248
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 37

Map ID: 27850108-1872

!(

SE-1 SE-2

BLIND RIVER

PETITE AMITE RIVER

NE-1

Railroad

Grade 377 Acres

Secondary

Impact Area

443 Acres

Primary

Impact Area

Footprint = 13.3 Acres

AMITE RIVER DIVERSION CANAL

NE-2

SW-2

Footprint = 18.8 Acres

1,033 Acres

Secondary

Impact Area

426 Acres

Primary

Impact Area

487 Acres

Proposed

Vegetative

Planting

1:26,000

±

0 1,000 2,000 3,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact Area

!( Existing Railroad Grade Cuts

Proposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of all Dredged MaterialBerms, Conveyance Channels, and Cuts Through ExistingDredged Material Berms. Spaces between Dredged MaterialBerms are shown larger than actual size for graphic purposes.

Figure: 10

1249
Alternatives Volume II  LCA Amite River Diversion Canal

Modification

EA WRDA 2007 Section 7006(e)(3) 3-16 March 2010

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1250
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 38

Map ID: 27850108-1873

LITTLE BAYOU CHENE BLANC

SE-1

NE-2

NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER Railroad Grade 377 Acres Secondary Impact Area

443 Acres

Primary

Impact Area

Footprint =

13.3 Acres

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

NW-2

ALLIGATOR BAYOU

1:40,000

0 2,000 4,000 6,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of allDredged Material Berms, Conveyance Channels,and Cuts Through Existing Dredged Material Berms.Spaces between Dredged Material Berms areshown larger than actual size for graphic purposes.

Figure: 11

1251
Alternatives Volume II  LCA Amite River Diversion Canal

Modification

EA WRDA 2007 Section 7006(e)(3) 3-18 March 2010

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1252
Image: 2009 Livingston Parish USDA-FSA-APFO NAIP MrSID Mosaic

Amite River Diversion Canal Modification

Ascension and Livingston Parishes, Louisiana

Date: February 2010Scale:Source: USGS/GEC

ALTERNATIVE 39

LITTLE BAYOU CHENE BLANC

Map ID: 27850108-1874

SE-1

NE-2 NE-1

SE-2

NE-3

BLIND RIVER

PETITE AMITE RIVER Railroad Grade 377 Acres Secondary Impact Area

443 Acres

Primary

Impact Area

Footprint =

13.3 Acres

BAYOU CHENE BLANC

AMITE RIVER DIVERSION CANAL

438 Acres

Proposed

Vegetative

Planting

956 Acres

Secondary

Impact Area

646 Acres

Primary

Impact Area

Footprint =

10.8 Acres

Footprint =

9.6 Acres

Footprint =

10.7 Acres

Railroad

Grade

SW-2

Footprint =

18.8 Acres

1,033 Acres

Secondary

Impact Area

426 Acres

Primary

Impact Area

487 Acres

Proposed

Vegetative

Planting

ALLIGATOR BAYOU

1:40,000

0 2,000 4,000 6,000

Feet

Map Extent

Legend

SubunitsPrimary Impact AreaSecondary Impact AreaExisting Railroad Grade CutsProposed Vegetative Plantings

Proposed Bank Openings & Conveyance Channels

Dredged Material BermsConveyance ChannelCut Through Existing Dredged Material Berm

SE-1

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

ProposedCut ThroughRailroad Grade

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

87 sq. ft. Dredged

Material Berm

Notes: Footprint acreage equals sum of all DredgedMaterial Berms, Conveyance Channels,and CutsThrough Existing Dredged Material Berms.Spaces between Dredged Material Berms areshown larger than actual size for graphic purposes.

Figure: 12

1253
Alternatives Volume II  LCA Amite River Diversion Canal

Modification

EA WRDA 2007 Section 7006(e)(3) 3-20 March 2010

  
 	

 
 	
 	

 

 
  	 
 	
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1254
Alternatives Volume II – LCA Amite River Diversion Canal

Modification

EA WRDA 2007 Section 7006(e)(3) 3-21 March 2010

acceptability). A comparison of the features included in each alternative within the final

array is found in Table 2.

Table 2. Comparison of Final Array of Alternatives

Alternative

North

Bank

Openings

South

Bank

Openings

Railroad

Grade

Openings

Berm

Plantings

(Acres)

Swamp

Plantings

(Acres)

33 3 0 1 5.0 438

34 0 1 2 2.7 487

35 0 1 0 2.2 0

36 3 1 3 7.8 925

37 0 2 2 4.9 487

38 3 1 1 7.2 438

39 3 2 3 9.9 925

1255

Section 7

DESIGN

1257

7-1

Design Assumptions

In the process of developing preliminary designs of proposed alternative plans for the

LCA ARDC Modification project, some design assumptions were made. First, it was

assumed that if the cross sections for the proposed conveyance channels were to mimic

the cross sectional makeup of relict cuts, found near Blind River, the proposed channels

would maintain a hydrologic equilibrium by maintaining flow rates large enough to

prevent the buildup of sediments within the channel over the lifespan of the project.

Secondly, it was assumed that with a 3H:1V and 4H:1V slope and seeding and mulching,

the slopes along the dredged material berm openings would remain stable. Two slope

dimensions were specified for portions on the proposed conveyance channels, depending

on the overall width of channel desired for each reach. The slope dimensions will be

revised upon completion of a full geotechnical investigation and slope stability analysis,

during the PED phase of the project. This is based on the assumption that the berm

material is primarily composed of clay, allowing for increased slope stability. The

alignment of the conveyance channels are based on preliminary data and LIDAR data.

Once all pertinent information is gathered, such as geotechnical investigation and a full

topographic survey, the final alignment and platform of the conveyance channels will be

adjusted accordingly. This information will not be available until the Plans and

Specifications phase of the project.

Erosion Control Requirements

In order to ensure that sediments do not leave the project area during construction, best

management practices (BMPs) will be implemented. These BMPs include the use of silt

fencing, hay bales and seeding and mulching in the appropriate locations.

Silt fencing would be utilized along the perimeter of the construction footprint to trap free

flowing sediment and hay bales would be placed in flow areas which tend to collect

excessive amounts of sediments. Seeding and mulching would be used to minimize

sediment runoff in the areas of cut on the existing ARDC spoil bank.

Preliminary cost estimates for the final array of alternatives included the use of these

BMPs. During the plans and specifications phase of the project the quantities and layout

for these implementations will be further determined.

Design Cross Sections

To scale cross sections depicting the proposed cuts through the dredged material berm

and for the conveyance channels are found in Figures 1 through 4. Sections depicting the

proposed Type 1 and Type 2 cuts through the existing railroad grade can be found in

Figure 5.

1259

CROSS-SECTIONS

1261

1263
1264
1265
1266
1267

	

	 
   

1269

Section 8

CONSTRUCTION

PROCEDURES

1271

8-1

Construction Procedures

It is estimated that the earthmoving portion of construction for the recommended plan

(Alternative 33) would take approximately six months. This duration includes the

mobilization and demobilization of the required equipment and laborers, construction of

all three cuts through dredged material berms and conveyance channels, one cut through

existing railroad grade. The first implementation of vegetative plantings within the

appropriate swamp and bottomland hardwood habitat will take approximately a year. A

secondary implementation of vegetative plantings will be required at a later date,

depending on the mortality rate of the first plantings. The second phase will last

approximately a year as well.

Once the appropriate equipment is mobilized to the project site via trucks and barges,

construction of the gaps through the dredged material berms would commence by

clearing and grubbing the designated footprints of construction on the north side of the

ARDC. Stumps are to be removed from the portions of excavation within the proposed

channels, but only trees would be cleared along the benches, 10-foot buffers and dredged

material and stump placement areas. Cleared trees would be placed in the same area with

the stumps and dredged material. Once clearing is completed at one cut location the

equipment would be mobilized to another cut location so excavation could begin.

Excavation of the cuts within the existing dredged material berms and the proposed

conveyance channels would be carried out by two short-reach, amphibious excavators.

As the equipment cuts its way into the cut locations, the dredged material would be

placed on the sides of the cuts and conveyance channels with 50-foot gaps placed

between the deposited material, every 300 feet. The excavated cuts and channels would

serve as the area in which equipment would move in and out of the construction area.

Upon completion of the excavation, vegetative plantings would be carried out within the

predetermined areas of the swamp and material placement. Approximately 173 trees per

acre would be planted. Each area planted would consist of approximately 10 percent 1-

gallon potted, 15 percent 3-gallon potted, and 75 percent bare-root seedlings. Cypress

and tupelo gum would be planted within the swamp floor areas and hardwoods such as

live oaks and sweet gum would be planted on both the newly created and existing

dredged material berms. Nutria guards would be required on every tree planted in order

to ensure a reasonable success rate. It is expected that the replanting of 50 percent of

these areas would be necessary within a few years of the conclusion of cut and channel

construction. No relocations of infrastructure or utilities would be required during

construction of the Alternative 33 (TSP).

1273

Section 9

OMRR&R

1275

9-3

Operations, Maintenance, Repair, Replacement, and Rehabilitation

Operations, maintenance, repair, replacement, and rehabilitation (OMRR&R)

requirements for the Alternative 33 (TSP) include a yearly inspection of the cut locations

and conveyance channels to ensure no flow interruption occurs, resulting from natural

occurrences such as wind-blown debris or fallen trees. Upon inspection it would be

determined if clearing and snagging or some other appropriate remedial operation is

necessary to restore the required conveyance within the features of Alternative 33 (TSP).

It is understood that the conveyance channels would be naturally altered over time,

eventually reaching a state of hydrologic equilibrium similar to the relict channels that

the conveyance channels were designed to mimic. These changes would most possibly

result in changes to the geomorphology of the channel along with a transition to a more

meandering channel makeup and would not reduce the expected benefits of Alternative

33 (TSP). Therefore, it is anticipated that little to no attempt to maintain the depth or

shoreline geometry of the conveyance channels would be necessary. The non-Federal

sponsor would be required to enforce any restrictions as identified in the easements to

ensure that the benefits of Alternative 33 (TSP) are retained. Table 1 shows a breakdown

of the OMRR&R costs.

Table 1

Alternative Inspection Cost

(Annual)

Clearing and Snagging

(Every 5 years)

Mobilization Clearing and

Snagging

33 (TSP) $2,000 $20,000 $21,000

34 $2,000 $20,000 $7,000

35 $2,000 $20,000 $7,000

36 $2,000 $20,000 $28,000

37 $2,000 $20,000 $14,000

38 $2,000 $20,000 $28,000

39 $2,000 $20,000 $35,000

Operations and maintenance costs are assumed to last for the 50-year period of analysis.

1277

Section 10

COST ESTIMATES

1279

10-1

Cost Estimates for Final Array of Alternatives

The following cost estimates were developed during the planning process as a means of

evaluating each restoration alternative and for use with the Institute for Water Resources

(IWR) Planning Suite analysis. Table 1 lists the costs estimated for Alternatives 33

through 39 (Final Array). Table 1 shows a summary of the items associated with each

cost estimate. Table 2 depicts the relationship between cost and benefits for the final

array of alternatives. The detailed cost estimates for the final array of alternatives are

found in the Cost Annex of this Appendix.

1281
10-2

Table 1. Summary of Costs Estimates for the Final Array

Item Alt. 33 Alt. 34 Alt. 35 Alt. 36 Alt. 37 Alt. 38 Alt. 39

Mob/Demob $250,000 $150,000 $150,000 $300,000 $200,000 $300,000 $350,000Earthwork $462,000 $332,000 $262,000 $788,000 $583,000 $698,000 $1,050,000Erosion Protection $46,000 $23,000 $23,000 $69,000 $45,000 $69,000 $92,000Vegetative Plantings $819,000 $906,000 $6,000 $1,720,000 $909,000 $822,000 $1,730,000Surveying $54,000 $22,000 $22,000 $70,000 $70,000 $70,000 $86,000Markups $631,000 $564,000 $176,000 $1,152,000 $695,000 $756,000 $1,289,000Planning Eng. &Design $189,000 $169,000 $53,000 $346,000 $209,000 $227,000 $387,000ConstructionManagement $110,000 $99,000 $31,000 $202,000 $122,000 $132,000 $226,000Total ConstructionCosts $2,560,000 $2,270,000 $720,000 $4,650,000 $2,830,000 $3,070,000 $5,210,000(25% Contingency) $640,000 $568,000 $180,000 $1,160,000 $708,000 $768,000 $1,300,000Real Estate $136,000 $144,000 $62,000 $259,000 $185,000 $178,000 $301,000Total First Costs* $3,340,000 $2,980,000 $962,000 $6,070,000 $3,720,000 $4,020,000 $6,810,000Interest DuringConstruction** $440,000 $390,000 $126,000 $797,000 $489,000 $528,000 $894,000Total ConstructionCost $3,780,000 3,370,000 $1,090,000 $6,870,000 $4,210,000 $4,550,000 $7,700,000Annual OMRR&RCosts $10,000 $7,000 $7,000 $11,000 $8,000 $11,000 $12,000Average AnnualCosts** $197,000 $174,000 $61,000 $351,000 $217,000 $236,000 $394,000

*First Quarter 2010 Dollars

** Average annual costs were determined over the six-year construction period with a discount rate of 4.375%

1282
10-3

Table 2. Costs and Benefits of the Final Array

Alternative

Acres

of

Benefit

AAHUs

Total

Construction

Cost

Annualized

Cost*

Annualized

Cost/AAHU

35* 820 334 $1,090,000 $61,000 $180

38* 2,422 1,013 $4,550,000 $236,000 $230

37 2,279 922 $4,210,000 $217,000 $240

39* 3,881 1,602 $7,700,000 $394,000 $250

36 3,061 1,268 $6,870,000 $352,000 $280

33 1,602 679 $3,780,000 $197,000 $290

34 1,459 589 $3,370,000 $174,000 $300

Cost Estimate Assumptions and Contingencies

Mobilization/Demobilization

It was assumed that a majority of the equipment used each day would be held at a

temporary loading/unloading zone. Therefore, this equipment would be barged in and

out on an as-needed basis. A base estimate of $150,000 was used for the Mobilization

and Demobilization costs (One cut) with an extra $50,000 for each additional cut. A D-6

dozer, two amphibious short-reach excavators, and a log skidder will be hauled in via a

truck and trailer. A barge, to be utilized for on-water work, will be brought in via a tug

boat as well. The costs were determined from the 2008 MII costbook and included

equipment and labor. A productivity of 100% was assumed for the Mob/Demob.

Earthwork

Cut Excavation

This is the amount of earthwork needed to dig through the dredged material berm and

into the swamp for each alternative. The material will be removed by using a D-6 dozer

and two amphibious sort-reach excavators. The short reach excavators have a reach of 30

feet in one direction and a 2.5 cubic yard bucket. The cycle time for these excavators is

120 cubic yards per hour. Short-reach excavators were chosen due to the larger buckets

they provide. Once the dredged material berm and the interior swamp are cleared of trees

and brush, both excavators will dig their way into the construction area. The excavated

material will be placed on both sides of the new cut and conveyance channels. Gaps of

approximately 50 feet in width will be placed throughout the material placement areas to

ensure that hydrologic flow is maintained throughout the area. The unit cost was

obtained by using the equipment’s cycle times and calculating the duration required for

creating the proposed cuts and conveyance channels. It was assumed that an 80%

productivity level would be achieved during this portion of construction. To

accommodate the superintendent over a six month period an added sustenance cost of

$6,720 will be included to the MCACES estimate (6 months x 4 weeks x 5 days x $56

1283
10-4

per day). The per diem rate of $56.00 per day for Baton Rouge, LA. was used. The

quantity was determined by GIS and cross-sections. The unit cost was calculated to be

$3.41 per cubic yard of material excavated.

Clearing & Grubbing

This cost included the clearing of all brush/trees and the removal of stumps within the

project footprint before excavation begins. Only the channel portions of the excavation

through the existing dredged material berms and the swamp floor would require full

clearing and grubbing, however the entire area was used for calculation of this cost item

to account for the brush removal and any additional cutting of trees into smaller lengths.

The stumps within the areas designated for material placement would not be removed.

The removed trees will be placed within the surrounding swamp along the conveyance

channels in a manner which ensures hydrologic flow remains. The stumps removed from

the newly-excavated conveyance channels will be placed along the spoil placement areas.

The unit cost was taken from the MII costbook for 2008. The area to be cleared was

derived from GIS analysis.

Tree Removal

Tree Removal would take place along the footprint of all excavated channels, areas

designated for material placement and the associated 10-foot gaps. Tree removal would

also take place along the benches to be created within the existing dredged material

berms. All stumps outside the channel would remain or be covered with the dredged

material. The unit cost was taken from the MII costbook for 2008. The area to be

cleared was derived from GIS analysis.

Erosion Protection

Seeding & Mulching

This price includes the seeding & mulching of the cut through the existing dredged

material berms along the ARDC. The area to be seeded was determined by GIS analysis.

The unit price was taken from the MII 2008 costbook.

Fertilizer

All areas to be seeded were determined to need fertilizer. It was estimated that each

existing spoil bank cut would need approximately ten 50-pound bags of fertilizer for

fertilization of the slopes. The unit price was taken from the MII 2008 costbook.

1284
10-5

Temporary Silt Fencing

Silt fencing would be used to stop sediment form leaving the construction site in the areas

surrounding the cut through the existing dredged material berms. Based on GIS analysis

it was determined that approximately 1,000 feet was needed for each cut. The unit price

was taken from the MII 2008 costbook.

Temporary Hay or Straw Bales

Hay bales would be used to control erosion or the loss of sediment in the low-lying areas

for proposed cuts through the existing dredged material berms. It was estimated that 50

bales were needed for each cut. The unit price was taken from the MII 2008 costbook.

Vegetative Plantings

Trees (Dredged Material Berms)

A cost of $10.00 per 3-gallon potted seedlings and a cost of $4.00 per 1-gallon potted

seedling were assumed. A unit price of $0.15 per bare-root seedling was assumed. It was

determined that an initial planting would consist of 15 percent 1-gallon potted seedlings

and 10 percent 3-gallon potted seedlings. Also included in the primary planting were 75

percent bare-root seedlings. A secondary planting of numbers totaling 50 percent of the

primary planting was assumed. When planting 173 trees per acre (Including secondary

planting), 26 would be 1- gallon potted, 17 would be 3-gallon potted, and 124 would be

bare-root seedlings. This equates to a per acre cost of $295. The area was determined

through GIS analysis.

Trees (Swamp Floor)

A cost of $10.00 per 3-gallon potted seedlings and a cost of $4.00 per 1-gallon potted

seedling were assumed. A unit price of $0.15 per bare-root seedling was assumed. It was

determined that an initial planting would consist of 15 percent 1-gallon potted seedlings

and 10 percent 3-gallon potted seedlings. Also included in the primary planting were 75

percent bare-root seedlings. A secondary planting of numbers totaling 50 percent of the

primary planting was assumed. When planting 173 trees per acre (Including secondary

planting), 26 would be 1- gallon potted, 17 would be 3-gallon potted, and 124 would be

bare-root seedlings. This equates to a per acre cost of $295. The area was determined

through GIS analysis.

Nutria Control/Labor

Nutria control is to be implemented for all vegetative planting within the swamp and on

the dredged material berms. Nutria control, including installation and planting labor for

all seedlings, would be implemented at a cost of $9.00 per seedling for all plantings and

each type (Swamp/Berms). This equates to a per acre cost of $1,553.

1285
10-6

Contingency

A 25% contingency was applied to the total construction cost to take into account

unforeseen issues that may arise during construction. The contingency was added as a

baseline for planning purposes as was the previous policy for developing preliminary

costs estimates. Because the contingency was applied consistently to all alternatives this

would not affect the CE/ICA analysis. A cost risk analysis was conducted before the

feasibility phase is completed to determine the true contingency required (59%). This

59% contingency was utilized for the MCACES estimated on the NER and TSP. A cost

contingency was not applied to the monitoring costs, resulting in an overall contingency

of 31 % for the project.

Final Design & Construction

Planning, Engineering and Design (PED)

It was assumed that the PED costs would be approximately 12% of the total project

construction cost.

Construction Management (CM)

It was assumed that the CM costs would be approximately 7% of the total project

construction cost for the preliminary cost estimates.

Real Estate

Real Estate Costs were provided based on the project footprints and easement

requirements. Because this cost is not normally included in the total construction costs, a

separate 25% contingency was applied.

Annualized Costs

This cost was determined by an economist at GEC. The current interest rate of 4.375%

was applied over a one year construction period to determine the appropriate annualized

cost.

Monitoring Costs

The estimated cost for the monitoring program is $2,971,200 for the first 10 years

following the completion of project construction. The details behind the Adaptive

Management and Monitoring costs are located in Appendix I.

Operations, Maintenance, Repair, Replacement, and Rehabilitation (OMRR&R)

Costs

The OMRR&R costs would include yearly inspections and clearing & snagging costs for

the channels when needed. It is assumed that the channels would require clearing and

1286
10-7

snagging every five years. A yearly inspection cost of $1000 per day for two days is

assumed each year ($2000 a year). In order to clear & snag an amphibious excavator

would be needed at $350 per hour, including labor. It is assumed that clearing &

snagging would take 20 hours per cut. An additional mobilization and demobilization of

$20,000 is included as well.

MCACES Assumptions and Contingencies

In order to obtain a more thorough analysis of the costs associated with the recommended

plan, a Micro-Computer Aided Cost Estimating System (MCACES) cost estimate was

conducted on the recommended plan. Table 4 presents the Total Project Cost Summary

Sheet for the MCACES estimate for the Tentatively Selected Plan (Alternative 33). This

estimate included all items previously listed in the cost estimates for the final array, with

the addition of various project-specific considerations such as contingencies and localized

cost items such as sales tax and labor rates. Most items listed in the MCACES report

were obtained from the 2008 English Costbook. Additional user defined costs were also

provided for items not found in the Costbook. These items include:

Earthmoving

Crew Boat Costs

Tug Boat Rental

Vegetative Plantings

All labor costs were adjusted to match current costs in Livingston Parish, Louisiana. A

contingency of 59% was determined based on a risk analysis as shown in this Appendix.

The costs for construction were escalated to 2011 dollars as shown in Table 4. The

overall cost of the recommended plan was estimated to be $8,540,000. The full

MCACES report is found in the Cost Annex of this Appendix.

Table 3. Cost Apportionment for the Tentatively Selected Plan

Item Federal Non-Federal Total

Construction $2,890,000 $1,560,000 $4,450,000

S&A $261,000 $140,000 $401,000

PED $347,000 $187,000 $534,000

LERDDs $117,000 $63,000 $180,000

Monitoring $1,930,000 $1,040,000 $2,970,000

Total* $5,550,000 $2,990,000 $8,540,000

S&A  Supervision and Administration (Construction Management)

PED  Planning, Engineering, and Design

LERRD  Lands, Easements, Rights-of-Way, Relocations, and Disposal Areas

* Costs include escalation in 2010 Dollars and Contingencies.

1287
10-8

1288
1289

10-10

Cost Risk Analysis

In an effort to identify the applicable cost and schedule risks inherent with

implementation of the TSP (Alternative 33), much of the process found within the

USACE guidance was utilized. Once all potential areas of risk were agreed upon by the

evaluation team, a Risk Register was created to help qualify and quantify the potential

impacts of these risks. A Monte Carlo simulation was run on the registry, which yielded

the applicable cost contingency to use for estimating construction costs of the TSP. For

this study it was determined that the appropriate contingency to use is 59 percent. This

cost contingency was not applied to monitoring costs due to existing contingencies

already found within this cost account. This resulted in an overall project contingency of

31%. More details on the Cost Risk Analysis are found in the Cost Annex of this

Appendix.

1291

ANNEX

Cost

1293

Costs Estimates for Final Array

Table 1. Cost Estimate for Alternative 33 (TSP)

Item Unit

Estimated

Quantity Unit Price

Estimated

Cost

Mobilization & Demobilization   ! !

Earthwork

 "#$	
 % &!'  !'


 ( )**
  & ! !


 	+ , -.	 /0 /	$1   ! &!&

Erosion Protection


 ( 2
 % !  !

34 * !  

,/0	%  3

 + !  '!

,/0	% 5% 	 6 7    !

Vegetative Plantings

, -8  7/1   & !'

, -6/0 3		1  9 & &!

. 	
	   ! 9'!&'&

Construction Costs $1,576,788

$%
   ! !

:0;;; < < !'




! "


 
 8
 < < 9&!

	
	
 
/
 < '< !'

Subtotal $2,561,093

	
	
 	


% 	 -<1 < !'

Real Estate

=
 	 -"/
>=1;;   ! !

Total Project Construction Cost $3,337,367

?
 8
 	
	
 - @ 	
1 9!&

,	 "/ 	 !''!&

Total Estimated Cost Rounded $3,780,000

>

4 	 - %! '< ?
1 9'!'

>

 A0	
 
 


; &!

,	 >$ >

 	 &!9

Rounded Annualized Cost $197,000

"/  
  8	B 	  0/
% / +	 0


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 +% +
 	 /

>$ >

 	 * 0	
  % 0	C +! '< 
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  % 	
	
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 8
 	
	
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; >	
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 	 	+ ! G +	 > ?/0/
	


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1295
Table 2. Cost Estimate for Alternative 34

Item Unit

Estimated

Quantity Unit Price

Estimated

Cost

Mobilization & Demobilization   ! !

Earthwork

 "#$	
 % '!'  !


 ( )**
   ! !


 	+ , -.	 /0 /	$1  9 ! 9!

Erosion Protection


 ( 2
 % !  9!

34 *   

,/0	%  3

 + !  !'

,/0	% 5% 	 6 7    '

Vegetative Plantings

, -8  7/1   & 99

, -6/0 3		1  9' & !

. 	
	  & ! '!&'

Construction Costs $1,409,673

$%
   ! !

:0;;; < < !9&




! "


 
 8
 < < &!

	
	
 
/
 < '< &9!''

Subtotal $2,262,981

	
	
 	


% 	 -<1 < !'

Real Estate

=
 	 -"/
>=1;;   ! !

Total Project Construction Cost $2,972,726

?
 8
 	
	
 - @ 	
1 &!'

,	 "/ 	 !!9&

Total Estimated Cost Rounded $3,370,000

>

4 	 - %! '< ?
1 !'

>

 A0	
 
 


; !&9

Total Average Annual Cost $173,671

Rounded Annualized Cost $174,000

"/  
  8	B 	  0/
% / +	 0


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	 0
 

+% +
 	 /

>$ >

 	 * 0	
  % 0	C +! '< 
! 
  % 	
	
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 8
 	
	
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; >	
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8/	*4	
 	 	+ ! G +	 > ?/0/
	


;; < 	


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 -<1! 


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F

1296
Table 3. Cost Estimate for Alternative 35

Item Unit

Estimated

Quantity Unit Price

Estimated

Cost

Mobilization & Demobilization   ! !

Earthwork

 "#$	
 % !9  !&


 ( )**
  ' ! &!


 	+ , -.	 /0 /	$1  ' ! !

Erosion Protection


 ( 2
 % !  9!

34 *   

,/0	%  3

 + !  !'

,/0	% 5% 	 6 7    '

Vegetative Plantings

, -8  7/1   & 99

, -6/0 3		1   & 

. 	
	   ! !&

Construction Costs $439,740

$%
   ! !

:0;;; < < '!9&




! "


 
 8
 < < !'&

	
	
 
/
 < '< !'9

Subtotal $720,786

	
	
 	


% 	 -<1 < 9!&'

Real Estate

=
 	 -"/
>=1;;   ! !

Total Project Construction Cost $962,983

?
 8
 	
	
 - @ 	
1 !&

,	 "/ 	 !9&!'

Total Estimated Cost Rounded $1,090,000

>

4 	 - %! '< ?
1 !9

>

 A0	
 
 


; !&9

Total Average Annual Cost $60,956

Rounded Annualized Cost $61,000

"/  
  8	B 	  0/
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0
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>$ >

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! 
  % 	
	
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8/	*4	
 	 	+ ! G +	 > ?/0/
	


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1297
Table 4. Cost Estimate for Alternative 36

Item Unit

Estimated

Quantity Unit Price

Estimated

Cost

Mobilization & Demobilization   ! !

Earthwork

 "#$	
  &!9'  '!&9


 ( )**
  & ! !


 	+ , -.	 /0 /	$1   ! 9!

Erosion Protection


 ( 2
 % &!  !

34 * !  9

,/0	%  3

 + !  !

,/0	% 5% 	 6 7    !

Vegetative Plantings

, -8  7/1  9 & !

, -6/0 3		1  & & '!9'

. 	
	  & ! !9!&&

Construction Costs $2,880,862

$%
   '! '!

:0;;; < < !!




! "


 
 8
 < < !'

	
	
 
/
 < '< !

Subtotal $4,650,770

	
	
 	


% 	 -<1 < !!&

Real Estate

=
 	 -"/
>=1;;   &! &!

Total Project Construction Cost $6,072,463

?
 8
 	
	
 - @ 	
1 '&'!

,	 "/ 	 !9&!'

Total Estimated Cost Rounded $6,870,000

>

4 	 - %! '< ?
1 !&

>

 A0	
 
 


; !'&

Total Average Annual Cost $351,365

Rounded Annualized Cost $351,000

"/  
  8	B 	  0/
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  % 	
	
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 	 	+ ! G +	 > ?/0/
	


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F

1298
Table 5. Cost Estimate for Alternative 37

Item Unit

Estimated

Quantity Unit Price

Estimated

Cost

Mobilization & Demobilization   ! !

Earthwork

 "#$	
  !9  '!&


 ( )**
   ! 9!


 	+ , -.	 /0 /	$1  9 ! !

Erosion Protection


 ( 2
 % !  !

34 * !  

,/0	%  3

 + !  '!

,/0	% 5% 	 6 7    !

Vegetative Plantings

, -8  7/1   & !'

, -6/0 3		1  9' & !

. 	
	  & ! '!'

Construction Costs $1,737,665

$%
   '! '!

:0;;; < < &!




! "


 
 8
 < < 9!

	
	
 
/
 < '< !'

Subtotal $2,833,088

	
	
 	


% 	 -<1 < '9!'

Real Estate

=
 	 -"/
>=1;;   9! 9!

Total Project Construction Cost $3,726,360

?
 8
 	
	
 - @ 	
1 9&!9

,	 "/ 	 !!

Total Estimated Cost Rounded $4,210,000

>

4 	 - %! '< ?
1 9!&&

>

 A0	
 
 


; 9!

Total Average Annual Cost $217,220

Rounded Annualized Cost $217,000

"/  
  8	B 	  0/
% / +	 0


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0
  +% +
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  % 0	C +! '< 
! 
  % 	
	
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?
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8/	*4	
 	 	+ ! G +	 > ?/0/
	


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1299
Table 6. Cost Estimate for Alternative 38

Item Unit

Estimated

Quantity Unit Price

Estimated

Cost

Mobilization & Demobilization   ! !

Earthwork

 "#$	
  !&  !'


 ( )**
  & ! !


 	+ , -.	 /0 /	$1   ! &!9

Erosion Protection


 ( 2
 % &!  !

34 * !  9

,/0	%  3

 + !  !

,/0	% 5% 	 6 7    !

Vegetative Plantings

, -8  7/1  ' & !

, -6/0 3		1  9 & &!

. 	
	   ! &!9

Construction Costs $1,889,280

$%
   '! '!

:0;;; < < '!'




! "


 
 8
 < < !'

	
	
 
/
 < '< !

Subtotal $3,074,155

	
	
 	


% 	 -<1 < '9!&

Real Estate

=
 	 -"/
>=1;;   '9! '9!

Total Project Construction Cost $4,020,694

?
 8
 	
	
 - @ 	
1 '!'

,	 "/ 	 !9!

Total Estimated Cost Rounded $4,550,000

>

4 	 - %! '< ?
1 !&'

>

 A0	
 
 


; !'&

,	 >$ >

 	 !&

Rounded Annualized Cost $236,000

"/  
  8	B 	  0/
% / +	 0


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  +% +
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 	 * 0	
  % 0	C +! '< 
! 
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 8
 	
	
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 	 	+ ! G +	 > ?/0/
	


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 5	/ A++ 
 H	* A++ A$2 -< 21! 	+ -<1! 7	
 -<1! 


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F

1300
F

Table 7. Cost Estimate for Alternative 39 (NER)

Item Unit

Estimated

Quantity Unit Price

Estimated

Cost

Mobilization & Demobilization   ! !

Earthwork

 "#$	
  &!  '9!


 ( )**
  ' ! '!


 	+ , -.	 /0 /	$1  ' ! !

Erosion Protection


 ( 2
 % !  '!

34 * !  !

,/0	%  3

 + !  !

,/0	% 5% 	 6 7    !'

Vegetative Plantings

, -8  7/1   & !&

, -6/0 3		1  & & '!9'

. 	
	 ( =*	  & ! !!

Construction Costs $3,222,054

$%
   9! 9!

:0;;; < < !99!9




! "


 
 8
 < < 9!

	
	
 
/
 < '< !

Subtotal $5,209,465

	
	
 	


% 	 -<1 < !!

Real Estate

=
 	 -"/
>=1;;   ! !

,	 	C 	
	
 	 !9!9

?
 8
 	
	
 - @ 	
1 9&!9

Total Estimated Cost $7,707,016

Total Estimated Cost Rounded $7,700,000

>

4 	 - %! '< ?
1 9!&

>

 A0	
 
 


; !'&

,	 >$ >

 	 &!'

Rounded Annualized Cost $394,000

"/  
  8	B 	  0/
% / +	 0


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	 0
 

+% +
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>$ >

 	 * 0	
  % 0	C +! '< 
! 
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 8
 	
	
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 5	/ A++ 
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1301

ANNEX 10-1

1303

1305

New Orleans District

Amite River Diversion Canal Modification Project

Ascension and Livingston Parishes, Louisiana

Cost Narrative Report

Draft Submittal

July, 2010

1307

Amite River Diversion Canal Modification Project

Cost Narrative

1. Project Description

a. General: Title VII of the Water Resources Development Act (WRDA) 2007

authorizes the Louisiana Coastal Area (LCA) program. The authority includes

requirements for comprehensive coastal restoration planning, program governance,

project modification investigations, a Science and Technology (S&T) program,

restoration project construction, a program for beneficial use of dredged material,

feasibility studies for restoration plan components, and other program elements.

b. Purpose: The LCA ARDC Integrated Feasibility Study is being developed as a

supplement to the Louisiana Coastal Area (LCA) Louisiana Ecosystem Restoration:

Comprehensive Coast-wide Ecosystem Restoration Study (LCA Near-term Restoration

Plan) and is intended to meet the requirements of the Water Resources Development Act

(WRDA) of 2007, Section 7006(e). This feasibility study is anticipated to result in a

Chief of Engineers Report containing a recommended LCA ARDC Plan (Plan). The Plan

addresses systematic restoration of bald cypress-tupelo swamp in areas affected by the

ARDC, and considers measures to prevent future bald cypress-tupelo swamp degradation

and conversion, restore sheet flow impaired by dredged material bank construction, and

protect vital socioeconomic and public resources. The Plan addresses ecosystem

restoration exclusively, and does not impair or alter the flood control capabilities of the

ARDC. The Plan is independent of, but synergistic with, other LCA near-term critical

features, as well as coastal restoration projects proposed under other authorities to

provide a holistic approach to restore impaired swamp habitat in the western Maurepas

Swamp.

c. Design Features: Features include dredge material berm cuts, railroad grade cuts,

conveyance channel cuts, vegetative clearing, and vegetative plantings.

2. Basis of Estimate

a. Basis of Design: LCA ARDC Integrated Feasibility Report and Draft Supplemental

Environmental Impact Statement (DSEIS) and the ARDC Phase 1 Environmental Site

Assessment. This project’s site plan is presented in Section 6 of Appendix L of the LCA

ARDC Integrated Feasibility Report and DSEIS.

b. Basis of Quantities: The estimate is based on the overall quantities provided by the

designer. These overall quantities along with additional detailed quantity estimates are

presented in Section 6 of Appendix L of the LCA ARDC Integrated Feasibility Report

and DSEIS.

1309
3. Design and Construction Schedule

Milestone Baseline Date

Begin Pre Construction Engineering and Design August 2010

Initiation of Monitoring Program November 2010

USACE and non-Federal sponsor negotiate PPA April 2012

Complete Plans and Specifications January 2012

Real Estate Acquisition August 2012

Award Contract October 2012

Construction Start 2012

Complete Construction- Earthwork 201

Complete 1st

Vegetation Planting April 2015

Complete 2nd

Vegetation Planting April 2018

Turnover Project to Local Sponsor August 2018

Complete Monitoring Program March 2023

a. Overtime: Overtime is included in the estimate for this project.

b. Construction Windows: It is estimated that civil construction of the project will take

approximately nine months to complete. Competition of the first and second vegetative

plantings will take approximately four years (including time for site assessments).

4. Contracting Plan

It is assumed that the project will be contracted to one prime construction contractor and one sub

contractor for the vegetative plantings.

5. Project Construction

a. Site Access: The construction laborers, equipment, and other personnel will be staged

in an area with access to the ARDC, most likely along LA-22 or north of the study area.

The necessary equipment will be transported in and out via barge on an as-needed basis.

Laborers will be transported in and out of the project area via crew boats on a daily basis.

b. Borrow Areas: There is no requirement for borrow material to be brought in from

outside the project area. All excavated material resulting from construction of the project

will be placed within the project footprint.

c. Construction Methodology:

1) Mobilization: This cost item includes the mobilization and demobilization of two

amphibious, short-reach excavators, a D6 Dozer, a log skidder, a barge, and a crew boat.

1310
This cost item includes the rental cost for the equipment and labor required to haul the

construction equipment to and from the job site. It is assumed that one truck driver and a

laborer is needed for each truck used to haul equipment. This item also includes the costs

for transporting the work crew in and out of the construction area with a crew boat.

The crew boat will be used to transport workers to and from the construction area on a

daily basis. Prices provided by Hackco, Inc. http://hackcoinc.com/ 337-762-4703. Price

includes captain, mob/demob, fuel, 1 crew boat throughout construction (22 weeks @ 7

days/week rental = 154 days). Prices are for the first quarter of 2010. 1 laborer will be

used for daily work on the barge, for a total of 840 hours (40 hours x 21 weeks). A work

barge is to be used for transporting equipment during construction. The barge will be

needed for 21 weeks @ 7days/week = 147 days.

2) The appropriate construction areas will be cleared of trees and stumps before

excavation of the cuts and conveyance channels begins. Some areas of the construction

footprint do not require that the stumps be removed (Sloped and disposal areas). All

stumps will be removed from the proposed conveyance channel excavation sites. This

cost item represents the removal of trees within the proposed construction footprint. All

trees will be disposed of on-site by selectively cutting the trees into smaller sections and

leaving them in the interior swamp in a manner that does not impeded hydrologic flow.

3) All cuts and channels will be excavated from the ARDC into the swamp areas.

Excavation will proceed from the ARDC into the swamp via the cuts and conveyance

channels as they are constructed. The conveyance channels will be the primary means of

transportation during construction.

For two amphibious, short-reach excavators (2.5 CY bucket) @ $285/hr (Rental price

provided by MVN, price includes crew), with a cycle time of 120 CY/hr of material

handled. A 50-minute hour and a 80% productivity markup were used for this calculation

(95,477 CY/120 CY/hr = 796 hr * 1.17 * 1.2 = 1,118 hrs). This gives an overall unit cost

of $3.33 per cubic yard (1,118 hrs x $285 = $318,630, $318,630/95,477 CY = $3.33). To

accommodate the superintendent over a six month period an added sustenance cost of

$6,720 will be included to the MCACES estimate (6 months x 4 weeks x 5 days x $56

per day). The per diem rate of $56.00 per day for Baton Rouge, LA. was used. This

raised the unit cost to $3.41 per cubic yard. This cost was obtained for the first quarter of

2010.

4) Material will be placed along the sides of the newly-constructed conveyance channels

as depicted in Section 3 of the LCA ARDC Integrated Feasibility Report and DSEIS.

Two amphibious, short-reach excavators will remove the material from the proposed

conveyance channel locations. Stumps from the channels will also be placed along the

appropriate disposal sites.

5) Vegetative plantings will be implemented within the appropriate areas in two phases.

Plantings will be implemented with a density of 173 trees per acre. The trees to be

planted will consist of approximately 15% 1-gallon potted seedlings, 10% 3-gallon potted

1311
seedlings and 75% bare-root seedlings. Nutria guards will be installed on all planted

trees. It is assumed that approximately 50% of the initial planting will need to be

replanted with a two year period of the initial plantings.

This item represents the primary and secondary plantings to be implemented on the

newly created dredged material berms upon completion of the earthmoving phase of

construction. A cost of $10.00 per 3 gal. potted plant, $4.00 per 1 gal. potted plant, and

$0.15 per seedling was assumed. It was determined that an initial planting consisting of

15% 1 gal. potted plants, 10% 3 gal. potted plants, and 75% bare-root seedlings would be

implemented. An initial planting will begin 7 months after the earthmoving phase of

construction is completed. A secondary planting of approximately 50% of the size of the

initial planting will begin 23 months after the initial planting is completed. When planting

173 trees per acre (Including secondary planting), 26 will be 1 gallon potted, another 17

will be 3 gallon potted and 129 will be bare-root for each acre planted. This equates to a

per acre cost of $295. The cost including installing nutria guards is $1,533 per acre. This

includes the labor required for planting the trees, purchasing the nutria guard materials,

and installing the guards. Productivity is already accounted for with the 50% replanting.

Prices provided by NCRS via the USFWS (Last Quarter 2009).

6) Surveying - It is assumed that a four-man crew will need to work with the following

breakdown: 3 days of mobilization per cut, 5 days per cut to layout the construction

footprint, 4 days per cut to produce as-builts. This is assumed to be done at 80%

productivity. This gives 30 days of work at an estimated cost of $1,500 per day, at 80%

efficiency for a total of $54,000. This quote was provided by Jim Smith of the Stanley

Group for the first quarter of 2010 (225-388-4208).

6. Lands and Damages

This cost item includes the Lands & Damages involved with the implementation of the proposed

action. No land will be purchased outright, but conservation, depositional, and flowage

easements will be required. A 59% contingency (as determined by the a risk analysis) will be

added to these costs. Details behind these costs may be found in Appendix J of the LCA ARDC

Integrated Report.

7. Planning, Engineering, and Design (PED)

These costs include the planning, engineering, and design required before construction of the

LCA ARDC project is to commence. It was estimated that this cost would be 12% of the total

estimated construction costs. A 59% contingency (based on a risk analysis) will be added to this

cost item.

8. Construction Management (CM)

These costs include the construction management required during construction of the LCA

ARDC project. It was estimated that this cost would be 9% of the total estimated construction

costs. A 59% contingency (based on a risk analysis) will be added to this cost item.

1312
9. Fish and Wildlife

This costs item includes the monitoring of project performance and for the project area, once

construction is completed. Monitoring will be conducted for the first ten years upon completion

of construction. This cost was determined from an Adaptive Management and Monitoring

Report, which is included in Appendix I of the LCA ARDC Integrated Report. An escalation of

2.6% is included for this cost item, therefore no escalation was applied within the Total Project

Cost Summary Sheet.

10. Environmental Concerns

To ensure that sediments do not leave the construction site during construction, Best

Management Practices including hay bales, silt fencing, and seeding and mulching will be

implemented.

11. Effective Dates for Labor, Equipment, and Material Pricing

The labor, equipment, and material pricing were developed using the MCACES 2008 English

Unit Cost Library, 2008 Labor Library, and the 2008 Equipment Library and the 2008

Equipment Library (Region III) for the base estimate. The base estimate has been currently

updated with current market wage rates for Livingston Parish, Louisiana, current quoted material

prices, production rates, fuel prices and specialty equipment costs in Louisiana. The index

pricing data has been prepared in June, 2008 dollars based on the data listed below and escalated

to February 2010 dollars.

a. Labor and Equipment Productivity: The estimate includes an overall Production Index

of 80 percent on selected items which is based on anticipated project difficulty, method

of construction, labor availability, supervision, job conditions, weather, and expected

delays. The productivity is built into the unit cost for some items as stipulated in the item

description.

12. Project Mark ups

a. Escalation The project costs were determined in 2010 dollars and escalated to

February 2011 dollars as shown in Section 10 of Appendix L of the LCA ARDC report.

b. Contingency A risk analysis was performed in accordance with ER 1110-2-1302.

The risk registry developed for this project is located in Section 10 Appendix L of the

LCA ARDC report. This analysis suggested a contingency of 59% be applied to the final

constructions costs, before Planning, Engineering and Design along with Construction

Management were added.

1313

Estimated by Jonathan Puls & Robert Manes

Designed by GEC, Inc.

Prepared by Jonathan Puls & Robert Manes

Preparation Date 12/17/2009

Effective Date of Pricing 12/17/2009

Estimated Construction Time Days

This report is not copyrighted, but the information contained herein is For Official Use Only.

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Title Page

This is the MCACES Cost Estimate for the LCA Amite River Diversion Canal Modification Project. The purpose of this project is to restore natural hydrologic

connectivity between the ARDC and the surrounding swamp habitat. It is proposed that five cuts, along with conveyance channels, be placed in the existing dredged

material berm to allow sediment and nutrient exchange throughout the area and to reduce impoundment.

1315

Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38

Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Project Cost Summary Report Page 1

Description Quantity UOM ContractCost ProjectCost C/O

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

Project Cost Summary Report 6,219,286 6,219,286

2,590,980.06 2,590,980.06

09 09 - Construction Costs 1.00 EA 2,590,980 2,590,980

400,010.40 400,010.40

09-01 09-01 Mob & Demob, Contractor 1.00 EA 400,010 400,010

245,719.32 245,719.32

09-01-01 09-01-01 Mob/Demob Equipment to be Towed 1.00 EA 245,719 245,719

245,719.32 245,719.32

09-01-01-01 09-01-01-01 Mob/Demob Crew Boat 1.00 EA 245,719 245,719

1,830.50 1,830.50

09-01-02 09-01-02 Mob/Demob Equipment to be Hauled and Operated 1.00 EA 1,831 1,831

502.49 502.49

09-01-02-01 09-01-02-01 Mob/Demob Log Skidder 1.00 EA 502 502

502.49 502.49

09-01-05-01 09-01-02-02 Mob Marsh Backhoe 2.00 EA 1,005 1,005

323.03 323.03

09-01-02-02 09-01-02-03 Mob/Demob D6 Dozer 1.00 EA 323 323

20,160.40 20,160.40

09-01-03 09-01-03 Workers 1.00 EA 20,160 20,160

132,300.18 132,300.18

09-01-04 09-01-04 Mob/Demob Equipment 1.00 EA 132,300 132,300

209,698.53 209,698.53

09-02 09-02 Site Preperation 1.00 EA 209,699 209,699

432,902.89 432,902.89

09-03 09-03 Earthwork 1.00 EA 432,903 432,903

115,896.41 115,896.41

09-04 09-04 Erosion Protection 1.00 EA 115,896 115,896

1,360,670.73 1,360,670.73

09-05 09-05 Vegetative Planting 1.00 EA 1,360,671 1,360,671

71,801.10 71,801.10

09-06 Surveying 1.00 EA 71,801 71,801

113,000.00 113,000.00

01 - Lands & Damages 1.00 EA 113,000 113,000

2,971,200.00 2,971,200.00

06 - Fish & Wildlife 1.00 EA 2,971,200 2,971,200

1317
Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38

Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Project Cost Summary Report Page 2

Description Quantity UOM ContractCost ProjectCost C/O

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

310,918.00 310,918.00

30 - PED 1.00 EA 310,918 310,918

233,188.00 233,188.00

31 - Construction Management 1.00 EA 233,188 233,188

1318
Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38

Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Project Direct Costs Report Page 3

Description Quantity UOM Contractor DirectLabor DirectEQ DirectMatl DirectSubBid DirectUserCost DirectCost C/O

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

0

Project Direct Costs Report 101,629 398,924 158,411 4,695,862 0 5,354,825

101,629.13 398,923.53 158,411.25 1,067,555.57 1,726,519.48

09 09 - Construction Costs 1.00 EA

Prime

Contractor 101,629 398,924 158,411 1,067,556 0 1,726,519

(Note: The overall construction for this project involves the excavation of three cuts, along with bifurcated conveyancve channels, through the dredged material berms and the interior swamp habitat,respectively. The dredged material will be placed along the existing berm, along the proposed conveyance channels, in order to maintain sheet flow throughout the area. Once these cuts and channels are

excavated and the construction area is allowed to settle, two phases of vegetative plantings will be implemented for portions of the interior swamp and for all of the dredged material placed duringconstruction. The productivity of this construction project is assumed to be 80% for specific cost items associated with this cost estimate. It is estimated that construction will begin in the last quarter of 2012.The TPCS found in Appendix L of the combined report gives the overall project costs along with all associated contigencies and escalation.)

15,599.24 285,239.63 0.00 0.00 300,838.86

09-01 09-01 Mob & Demob,

Contractor 1.00 EA

Prime

Contractor 15,599 285,240 0 0 0 300,839

(Note: This cost item includes the mobilization and demobilization of two amphibious, short-reach excavators, a D6 Dozer, a log skidder, a barge, and a crew boat. This cost item includes the renatal cost for

the equipment and labor required to haul the construction equipment to and from the job site. It is assumed that one truck driver and a laborer is needed for each truck used to haul equipment. This item also

includes the costs for transporting the work crew in and out of the construction area with a crew boat.)

0.00 184,800.00 0.00 0.00 184,800.00

09-01-01 09-01-01 Mob/Demob

Equipment to be Towed 1.00 EA

Prime

Contractor 0 184,800 0 0 0 184,800

(Note: This cost item represents the cost for renting a crew boat to use during construction.)

0.00 184,800.00 0.00 0.00 184,800.00

09-01-01-01 09-01-01-01 Mob/Demob

Crew Boat 1.00 EA

Prime

Contractor 0 184,800 0 0 0 184,800

(Note: The crew boat will be used to transport workers to and from the construction area on a daily basis.)

0.00 1,200.00 0.00 0.00 1,200.00

USR Mob/Demob Crew Boat 154.00 DAY Prime Contractor 0 184,800 0 0 0 184,800 E

(Note: The crew boat will be used to transport workers to and from the construction area on a daily basis. Prices provided by Hackco, Inc. Prices provided by Hackco, Inc. http://hackcoinc.com/ 337-762-4703 Includes captain, mob/demob, fuel, 1 crew boat is needed throughout construction (22 weeks @ 7 days/week rental = 154 dyas) Prices are for the first quarter of 2010.)

437.05 939.63 0.00 0.00 1,376.68

09-01-02 09-01-02 Mob/Demob

Equipment to be Hauled and Operated 1.00 EA

Prime

Contractor 437 940 0 0 0 1,377

(Note: This cost item represent the Mob/Demob of the equipment to be hauled to the job site. This equipment includes a log skidder, two hydraulic excavators and a D6 dozer.)

116.55 261.36 0.00 0.00 377.91

09-01-02-01 09-01-02-01 Mob/Demob

Log Skidder 1.00 EA

Prime

Contractor 117 261 0 0 0 378

(Note: This cost item is for the Mob/Demob of a log skidder.)

58.27 130.68 0.00 0.00 188.96

RSM 015436500100 Mobilization ordemobilization, dozer, loader, backhoe orexcavator, above 250 H.P., up to 50 miles

2.00 EA Prime Contractor 117 261 0 0 0 378 N

(Note: The quantity is given as two to account for both the mobilization and the demobilization. Labor and equipment is included in the cost.)

116.55 261.36 0.00 0.00 377.91

09-01-05-01 09-01-02-02 Mob Marsh 2.00 EA Prime 233 523 0 0 756

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Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38

Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Project Direct Costs Report Page 4

Description Quantity UOM Contractor DirectLabor DirectEQ DirectMatl DirectSubBid DirectUserCost DirectCost C/O

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

09-02 09-02 Site Preperation 0

Backhoe Contractor

(Note: This cost item represent the Mob/Demob cost of hauling two amphibious short-reach hydraulic excavator to be used to construct the cuts and conveyance channels. This cost includes equipment andlabor.)

58.27 130.68 0.00 0.00 188.96

RSM 015436500100 Mobilization ordemobilization, dozer, loader, backhoe orexcavator, above 250 H.P., up to 50 miles

4.00 EA Prime Contractor 233 523 0 0 0 756 N

(Note: The quantity is given as four to account for both the mobilization and the demobilization of both excavators. Labor and equipment is included in the cost. These excavators are have a 30-foot reachand a 2.5 CY bucket. They also have a cycle time of 120 CY/hr.)

87.41 155.54 0.00 0.00 242.95

09-01-02-02 09-01-02-03 Mob/Demob

D6 Dozer 1.00 EA

Prime

Contractor 87 156 0 0 0 243

(Note: This cost item is for the Mob/Demob of a D6 dozer.)

43.71 77.77 0.00 0.00 121.47

RSM 015436500020 Mobilization ordemobilization, dozer, loader, backhoe orexcavator, 70 H.P. to 250 H.P., up to 50miles

2.00 EA Prime Contractor 87 156 0 0 0 243 N

(Note: The quantity is given as two to account for both the mobilization and the demobilization. Labor and equipment is included in the cost.)

15,162.18 0.00 0.00 0.00 15,162.18

09-01-03 09-01-03 Workers 1.00 EA

Prime

Contractor 15,162 0 0 0 0 15,162

(Note: This cost includes the labor needed to help with the loading/unloading of the barges on the docking and upkeep required on a daily basis.)

18.05 0.00 0.00 0.00 18.05

MIL B-LABORER Laborers, (Semi-Skilled) 840.00 HR Prime Contractor 15,162 0 0 0 0 15,162 N

(Note: 1 laborer will be used for daily work on the barge. In total (1 barge @ 840 hours).)

0.00 99,500.00 0.00 0.00 99,500.00

09-01-04 09-01-04 Mob/Demob

Equipment 1.00 EA

Prime

Contractor 0 99,500 0 0 0 99,500

(Note: This cost item represents the equipment needed for the Mob/Demob of the barge to be used during construction. A tug boat is rented to bring the barge to and from the job site before and after theearthmoving phase of construction.)

0.00 400.00 0.00 0.00 400.00

MAP XX0XX700 WORK BARGE, FLATDECK , 500 TON APPROX. 60'x 35' x8',WOOD DECK (Mob/Demob)

147.00 DAY Prime Contractor 0 58,800 0 0 0 58,800 E

(Note: A work barge is to be used for transporting equipment during construction. The barge will be needed for 21 weeks @ 7days/week = 147 days.)

0.00 1,850.00 0.00 0.00 1,850.00

USR Tug Boat - 900 HP 22.00 DAY Prime Contractor 0 40,700 0 0 0 40,700 E

(Note: A tug boat is required to mob/demob the barges to be used during construction and tp push the barges from one cut to another. Price obtained from B&J Tug Boat and Barge Rentals 337-912-0974,

includes captain. 4 days for mob/demob, crew boat can push barge from cut to cut and to loading zone (Twin 250 hp engines). Price obtained in the first quarter of 2010.)

50,949.24 106,760.34 0.00 0.00 157,709.57

1.00 EA

Prime

Contractor 50,949 106,760 0 0 157,710

1320
Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38

Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Project Direct Costs Report Page 5

Description Quantity UOM Contractor DirectLabor DirectEQ DirectMatl DirectSubBid DirectUserCost DirectCost C/O

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

RSM 329113161020 Soil preparation, 60,000.00 0(Note: This cost item represents the general clearing of the areas to be excavated along the dredged material berms and the proposed conveyance channels. A log skidder and a laborer will be used tochainsaw the trees and the dozer and will help push them to the appropriate disposal areas. This cost includes both equipment and labor.)

520.48 1,022.20 0.00 0.00 1,542.67

HNC 311313101050 Selective clearing, wetclearing, heavy brush and trees, excludesremoval offsite

31.00 ACR Prime Contractor 16,135 31,688 0 0 0 47,823 N

(Note: This cost item represents the removal of trees within the proposed construction footprint. All trees will be disposed of on-site by selectively cutting the trees into smaller sections and leaving them in

the interior swamp in a manner that does not impeded hydrologic flow.)

1,123.05 2,421.69 0.00 0.00 3,544.73

RSM 311110100350 Clearing & grubbing,heavy stumps, to 24" diameter, grub stumpsand remove

31.00 ACR Prime Contractor 34,814 75,072 0 0 0 109,887 N

(Note: This cost item represents the removal of all shrubs, stumps and debris within the proposed project footprint. The stumps will be piled along the proposed dredged material disposal areas. All othermaterial will be disposed of along the swamp floor in a manner that does not impede hydrologic flow within the area.)

0.00 0.00 0.00 325,576.57 325,576.57

09-03 09-03 Earthwork 1.00 EA

Prime

Contractor 0 0 0 325,577 0 325,577

(Note: This cost item represents the earthmoving required to construct the proposed cuts through the dredged material berms and the conveyance channels into the interior swamp. The equipment will digtheir way in by utilizing the excavated channel as a means of moving into and out of the construction area. The excavators will be amphibious.)

0.00 0.00 0.00 3.41 3.41

USR Mechanical Earthmoving 95,477.00 BCY Prime Contractor 0 0 0 325,577 0 325,577 Sb

(Note: For two amphibious, short-reach excvators (2.5 CY bucket) @ $285/hr (Rental price provided by MVN, including crew and per diem), with a cycle time of 120 CY/hr of material handled. A 50-

minute hour and a 80% productivity markup were used for this calcualtion (95,477 CY/120 CY/hr = 796 hr * 1.17 * 1.2 = 1,118 hrs). This gives an over all unit cost of $3.33 per cubic yard (1,118 hrs *$285 = $318,630, $318,630/95,477 CY = $3.33). The rental price used to calculate the $3.33 per CY unit price for excavating includes per diem. This accommodates the heavy equipment operators. Toaccommodate the superintendent over a six month period an added sustenance cost of $6,720 will be included to the MCACES estimate (6 months x 4 weeks x 5 days x $56 per day). The per diem rate of$56.00 per day for Baton Rouge, LA. was used. This raised the unit cost to $3.41 per cubic yard. This cost was obtained for the first quarter of 2010.)

35,080.66 6,923.56 27,726.25 0.00 69,730.48

09-04 09-04 Erosion Protection 1.00 EA

Sub-Contractor

- Erosion Control 35,081 6,924 27,726 0 0 69,730

(Note: This cost item represents the implementation of silt fensing and hay bales used to prevent the loss of sediment due to construction activites. Silt fensing will be utilized along the entire perimeter of

the construction area. Hay bales will be used in areas in which water tends to convey through the site. Seeding and mulching will be utilized along the newly formed slopes to limit the loss of sediments and

to stabilize the slopes. These prices include equipment and labor.)

0.15 0.12 0.30 0.00 0.56

RSM 329219131100 Seeding, mechanicalseeding hydro or air seeding for large areas,includes lime, fertilizer and seed

60,000.00 SY Sub-Contractor -

Erosion Control

8,877 6,913 18,000 0 0 33,790 OLEM

(Note: This item represents the seeding implemented to ensure erosion reduction and stability along the newly excavated areas. This cost includes equipment and labor.)

2.54 0.00 0.79 0.00 3.33

RSM 312513101120 Erosion control, siltfence, polypropylene, 3' high, includes 7.5'posts

3,000.00 LF Sub-Contractor -

Erosion Control

7,616 0 2,370 0 0 9,986 OLM

(Note: This item represents the silt fencing to be installed along the entire perimeter of the construction area to reduce the amount of sediment leaving the job site. This cost included equipment and labor.)

0.31 0.00 0.11 0.00 0.42

SY Sub-Contractor - 18,564 0 6,600 0 25,164 OLM

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Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38

Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Project Direct Costs Report Page 6

Description Quantity UOM Contractor DirectLabor DirectEQ DirectMatl DirectSubBid DirectUserCost DirectCost C/O

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

mulching, polyethylene film, 1-1/2 mil Erosion Control

(Note: This item represent the mulching used along with the seeding to reduce ersoion within the work area. This cost include equipment and labor.)

0.19 0.09 6.05 0.00 6.32

RSM 312513101250 Synthetic erosioncontrol, hay bales, staked

125.00 LF Sub-Contractor -

Erosion Control

23 11 756 0 0 790 N

(Note: This item represents the hay bales to be placed in water conveynace areas throughout the construction area to reduce sediment loss due to erosion. This cost includes the nay bales and the labor toinstall them.)

0.00 0.00 130,685.00 687,979.00 818,664.00

09-05 09-05 Vegetative Planting 1.00 EA

Sub-Contractor

- VegetativePlantings 0 0 130,685 687,979 0 818,664

(Note: This cost includes the initial and secondary vegetative plantings to be implemented along newly-created dredged material placement areas and portions of the swamp floor. It includes the planting ofbaldcypress and tupelo gum as well as upland tree species such as live oaks.)

0.00 0.00 295.00 0.00 295.00

USR Plantings (Material Only - DredgedMaterial Berms - 25% 1 gal., 25% 3 gal., and50% seedlings)

5.00 ACR Sub-Contractor -

Vegetative Plantings

0 0 1,475 0 0 1,475 M

(Note: This item represents the primary and secondary plantings to be implemented on the newly created dredged material berms upon completion of the earthmoving phase of construction. A cost of $10.00

per 3 gal. potted plant, $4.00 per 1 gal. potted plant, and $0.15 per seedling was assumed. It was determined that an initial planting consisting of 15% 1 gal. potted plants, 10% 3 gal. potted plants, and 75%bare-root seedlings would be implemented. An initial planting will begin 7 months after the earthmoving phase of construction is completed. A secondary planting of approximately 50% will begin 23months after the initial planting is completed. When planting 165 trees per acre (Including secondary planting), 25 will be 1 gal. potted, another 17 will be 3 gal. potted and 124 will be bare-root for each

acre planted. This equates to a per acre cost of $283. The cost installing nutria guards is $1,485 per acre. This price includes the labor required for planting the trees and installing the gaurds, as well as thenutria guard materials. The area was determined through GIS analysis. Productivity is already accounted for with the 50% replanting. Prices provided by NCRS via the USFWS (Last Quarter 2009).)

0.00 0.00 295.00 0.00 295.00

USR Plantings (Material Only - SwampFloor - 25% 1 gal., 25% 3 gal., and 50%seedlings)

438.00 ACR Sub-Contractor -

Vegetative Plantings

0 0 129,210 0 0 129,210 M

(Note: This item represents the primary and secondary plantings to be implemented on the newly created dredged material berms upon completion of the earthmoving phase of construction. A cost of $10.00

per 3 gal. potted plant, $4.00 per 1 gal. potted plant, and $0.15 per seedling was assumed. It was determined that an initial planting consisting of 15% 1 gal. potted plants, 10% 3 gal. potted plants, and 75%bare-root seedlings would be implemented. An initial planting will begin 7 months after the earthmoving phase of construction is completed. A secondary planting of approximately 50% will begin 23months after the initial planting is completed. When planting 165 trees per acre (Including secondary planting), 25 will be 1 gal. potted, another 17 will be 3 gal. potted and 124 will be bare-root for each

acre planted. This equates to a per acre cost of $283. The cost installing nutria guards is $1,485 per acre. This price includes the labor required for planting the trees and installing the gaurds, as well as thenutria guard materials. The area was determined through GIS analysis. Productivity is already accounted for with the 50% replanting. Prices provided by NCRS via the USFWS (Last Quarter 2009).)

0.00 0.00 0.00 1,553.00 1,553.00

USR Nutria Control (Material + Installation)and Planting Labor

443.00 ACR Sub-Contractor -

Vegetative Plantings

0 0 0 687,979 0 687,979 Sb

(Note: Nutria Control is to be implemented for all vegetative planting within the swamp and on the dredged material berms. Nutria control, including installation and planting labor for all seedlings, would

be implemented at a cost of $9.00 per seedling for all plantings and each type (Swamp/Berms). Prices provided by NRCS via the USFWS (Last Quarter 2009).)

0.00 0.00 0.00 54,000.00 54,000.00

09-06 Surveying 1.00 EA

Prime

Contractor 0 0 0 54,000 0 54,000

(Note: This cost item represents the survey work required during construction. Surveying will be conducted to specify the area of construction prior to the site preperation and earthmoving phases ofconstruction. Survey work will also be conducted to ensure that all cuts and conveyance channels are constructed to specifications.)USR Construction Surveying 1.00 LS Prime Contractor 0 0 0 54,000 0 54,000 Sb

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Print Date Fri 16 July 2010 U.S. Army Corps of Engineers Time 09:19:38

Eff. Date 12/17/2009 Project LCA-ARDC: LCA-ARDC

COE Standard Report Selections Project Direct Costs Report Page 7

Description Quantity UOM Contractor DirectLabor DirectEQ DirectMatl DirectSubBid DirectUserCost DirectCost C/O

Labor ID: LB08NO_LA EQ ID: EP07R06 Currency in US dollars TRACES MII Version 3.01

(Note: It is assumed that a four-man crew will need to work with the following breakdown: 3 days of mobilization per cut 5 days per cut to layout the construction footprint 4 days per cut to produce asbuilts 80% productivity This gives 30 days of work at an estimated cost of $1,500 per day, at 80% efficiency for a total of $54,000 This quote was provided by Jim Smith of the Stanley Group for the first

quarter of 2010 (225-388-4208).)

0.00 0.00 0.00 113,000.00 113,000.00

01 - Lands & Damages 1.00 EA 0 0 0 113,000 0 113,000

0.00 0.00 0.00 113,000.00 113,000.00

USR Lands & Damages 1.00 EA 0 0 0 113,000 0 113,000 Sb

(Note: This cost item includes the Lands & Damages involved with the implementation of the proposed action. No land will be purchased outright, but conservation, depositional, and flowage easementswill be required. A 37% contigency (as determined by the a risk analysis) will be added to these costs. Details behind these costs may be found in Appendix J of the LCA ARDC Integrated Report.)

0.00 0.00 0.00 2,971,200.00 2,971,200.00

06 - Fish & Wildlife 1.00 EA 0 0 0 2,971,200 0 2,971,200

0.00 0.00 0.00 2,971,200.00 2,971,200.00

USR Fish and Wildlife 1.00 EA 0 0 0 2,971,200 0 2,971,200 Sb

(Note: This costs item includes the monitoring of project performance and for the project area, once construction is completed. Monitoring will be conducted for the first ten years upon completion of

construction. This cost was determined from an Adaptive Management and Monitoring Report, which is included in Appendix I of the LCA ARDC Integrated Report.)

0.00 0.00 0.00 310,918.00 310,918.00

30 - PED 1.00 EA 0 0 0 310,918 0 310,918

0.00 0.00 0.00 310,918.00 310,918.00

USR Planning, Engineerin, and Design 1.00 EA 0 0 0 310,918 0 310,918 Sb

(Note: These costs include the planning, engineering, and design required before construction of the LCA ARDC project is to commence. It was estimated that this cost would be 12% of the total estimatedconstruction costs. A 37% contingency (based on a risk analysis) will be added to this cost item.)

0.00 0.00 0.00 233,188.00 233,188.00

31 - Construction Management 1.00 EA 0 0 0 233,188 0 233,188

0.00 0.00 0.00 233,188.00 233,188.00

USR Construction Management 1.00 EA 0 0 0 233,188 0 233,188 Sb

(Note: These costs include the construction management required during construction of the LCA ARDC project. It was estimated that this cost would be 9% of the total estimated construction costs. A 37%contingency (based on a risk analysis) will be added to this cost item.)

1323

ANNEX 10-2

1325

LOUISIANA COASTAL AREA -

AMITE RIVER DIVERSION

RISK ANALYSIS REPORT

FOR

MISSISSIPPI RIVER VALLEY DISTRICT,

NEW ORLEANS, LA.

Prepared for:

U.S. Army Corps of Engineers

Prepared by:

GEC, Inc.

Date: 1-21-10

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i

TABLE OF CONTENTS

EXECUTIVE SUMMARY .......................................................................................................... 1

1. PURPOSE................................................................................................................................ 2

2. BACKGROUND ..................................................................................................................... 2

3. REPORT SCOPE ................................................................................................................... 2

3.1 Project Scope ....................................................................................................................3

3.2 USACE Risk Analysis Process.........................................................................................3

4. METHODOLOGY/PROCESS.............................................................................................. 3

4.1 Identify and Assess Risk Factors ......................................................................................4

4.2 Quantify Risk Factor Impacts ...........................................................................................5

4.3 Analyze Cost Estimate and Contingency..........................................................................5

5. KEY ASSUMPTIONS............................................................................................................ 6

6. RISK ANALYSIS RESULTS ................................................................................................ 7

6.1 Risk Register.....................................................................................................................7

6.2 Cost Risk Analysis - Cost Contingency Results.............................................................11

7. MAJOR FINDINGS/OBSERVATIONS ............................................................................ 13

8. MITIGATION RECOMMENDATIONS........................................................................... 15

LIST OF TABLES

Table 1. Work Breakdown Structure by Feature ........................................................................... 9

Table 2. Sample Project Contingencies (Base Cost Plus Cost Contingencies) ........................... 11

FIGURE

Figure 1. Frequency Result..........................................................................................................

Figure 2. Cumulative Frequency Results 12

12

Figure 3. Cumulative Sensitivity Results 13

Figure 4. Sensitivity Bar Chart 14

APPENDIX

APPENDIX A Detailed Risk Register

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EXECUTIVE SUMMARY

This report reviews the cost risk analysis (CRA) for the Louisiana Coastal Area Amite

River Diversion Canal (LCA ARDC) Modification project Integrated Feasibility Report

and Environmental Impact Statement. The results of this analysis provide the applicable

cost contingency to use during cost estimation, while also highlighting the risks

associated with the study, design, and construction phases of the project.

The LCA ARDC Modification Project has been identified as a near-term critical feature

recommended for study in the November 2004 LCA Ecosystem Restoration Study (2004

LCA Plan). Construction of the canal has caused a loss of hydrologic connectivity, a

reduction in sediment and nutrient transport, and increased impoundment within the study

area. These man-made impacts have resulted in the gradual degradation of the interior

swamp habitat as it transitions to a freshwater marsh and eventually an open water

habitat. The goal of this project is restore the natural hydrologic water regime within the

study area, thereby improving the freshwater swamp habitat.

The CRA described in this report was implemented in an effort to determine a true

contingency cost required for cost estimating and based on the risk items associated with

the project. The results of this analysis are determined by qualifying and quantifying all

potential cost risks and running a Monte Carlo simulation to produce the frequency

spectrum and probability range for the applied risk costs. The cost contingency is

obtained from the 80-percent contingency as determined by this analysis.

A total of 33 potential risk items were developed by the CRA team and applied to a risk

registry for analysis. Assumptions were made for each risk item before running the

Monte Carlo simulation. The result of the simulation gave a 59 percent contingency at

the 80-percent confidence level.

The contingency cost for this project was utilized for a Micro Computer Aided Cost

Estimation Software (MCACES) estimation of the costs associated with the

recommended plan (Alternative 33). The potential cost risks developed during this

analysis also serve as an indicator of how to avoid unforeseen escalation of project costs

throughout project implementation and therefore, may be used as a valuable tool in all

future aspect of the project study, design, and construction planning and estimation.

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1. PURPOSE

The purpose of this project is to address the systematic restoration of bald cypress-tupelo swamp

in areas affected by the ARDC, while considering measures to prevent future bald cypress-tupelo

swamp degradation and conversion, restore sheet flow impaired by dredged material bank

construction, and protect vital socioeconomic and public resources. The study area is located in

the western Maurepas Swamp in the vicinity of Head of Island, Louisiana and is centered around

the ARDC, a flood control channel that extends from the Amite River (at Mile 25) to the Blind

River (at Mile 4.8) in Ascension and Livingston Parishes. This project would provide hydrologic

restoration in the western Maurepas Swamp.

2. BACKGROUND

Since the construction of the ARDC in 1963, a large portion of the western Maurepas Swamp

has been cut off from fresh water, sediments, and nutrients historically provided by the Amite

River and other waterbodies in the area because of the construction of spoil banks on either side

of the canal. This disruption of natural processes has prevented fresh water from circulating in

the swamp during high water flow periods (which prevents nutrients and sediments from

reaching the swamps), and has prevented the swamp from draining during low water flow

periods (which prevents seedling germination and establishment). Consequently, the swamp is

impounded, the trees are highly stressed, and little to no regeneration of bald cypress and water

tupelo trees (the dominant vegetation in the western Maurepas Swamp) is occurring. These

factors, combined with periodic salinity increases as a result of saline storm surge waters from

hurricanes, have severely impaired the western Maurepas Swamp, which is at great risk of

conversion to fresh marsh, which would ultimately convert to open water.

The Amite River Diversion Canal Modification Project has been identified as a near-term critical

feature recommended for study in the November 2004 Louisiana Coastal Area (LCA) Ecosystem

Restoration Study (2004 LCA Plan). The Project was authorized under Section 7006(e) of the

Water Resources Development Act (WRDA, Public Law 110-114). The Federal sponsor for the

Project is the U.S. Army Corps of Engineers (USACE) and the non-Federal sponsor is the State

of Louisiana through the Louisiana Coastal Protection and Restoration Authority (CPRA).

3. REPORT SCOPE

The scope of this risk analysis report is to calculate and present the cost 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. This report presents the contingency

results for both cost risks for all project features.

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

Coastal Area (LCA) program. The authority includes requirements for comprehensive coastal

restoration planning, program governance, project modification investigations, a Science and

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Technology (S&T) program, restoration project construction, a program for beneficial use of

dredged material, feasibility studies for restoration plan components, and other program

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

31, 2005. The report includes the project technical scope and estimates, as developed and

presented by (list the name of the product developer by district or design firm). Consequently,

these documents serve as the basis for the risk analysis. In general terms, the construction scope

consists of the following:

3.1 USACE Risk Analysis Process

This cost risk analysis (CRA) 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 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 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 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 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 CRA was conducted by a team of contractors, assembled by GEC, Inc., with varying

backgrounds, which include construction, engineering, biological impacts, project management,

and cost estimation. The analysis was conducted over approximately a month and a half and

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completed on January 11th

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 may also be 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.

, 2010. This CRA outcome has recieved approval by Agency

Technical Review (ATR) and all comments received from this review have been backchecked

and closed out.

In simple terms, contingency is an amount added to a cost estimate 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 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. Risk analysis results would be provided in section 6.

4.1 Identify and Assess Risk Factors

Identifying the risk factors via the CRA team 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.

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 CRA team is obtained

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using creative processes such as brainstorming or other facilitated risk assessment meetings. In

practice, a combination of professional judgment from the CRA team and empirical data from

similar projects is desirable and is considered.

A formal CRA meeting was held at GEC for the purposes of identifying and assessing risk

factors. The meeting on December 7th

Project/program managers.

, 2009 included capable and qualified representatives from

multiple project team disciplines and functions, for example:

Contracting/acquisition.

Real Estate.

Relocations.

Environmental.

Civil, structural, geotechnical, and hydraulic design.

Cost and schedule engineers.

Construction.

The formal meeting focused primarily on risk factor identification using brainstorming

techniques, but also included some facilitated discussions based on risk factors common to

projects of similar scope and geographic location.

Additionally, numerous conference 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 resulting product from the CRA teams discussions is captured within a risk register as

presented in section 6 for both cost risk concerns. Note that the risk register records the CRA

teams risk concerns, discussions related to those concerns, and potential impacts to the current

cost 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 Contingency

Contingency is analyzed using the Crystal Ball software, an add-in to the Microsoft Excel format

of the cost estimate. Monte Carlo simulations are performed by applying the risk factors

(quantified as probability density functions) to the appropriate estimated cost elements identified

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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. 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

This section presents the key assumptions utilized for the CRA. Key assumptions are those that

are most likely to significantly effect the determinations and/or estimates of risk presented in the

CRA. The key assumptions are important to help ensure that project leadership and other

decision makers understand the steps, logic, limitations, and decisions made in the risk analysis,

as well as any resultant limitations on the use of outcomes and results.

The following key assumptions were made by the CRA team.

The total construction cost was determined by running a MCACES analysis for

the recommended plan (Alternative 33).

An Agency Technical Review will be run on the CRA results.

There is only one construction account involved with this project.

The 80-percent confidence contingency would be used as the resultant

contingency in the CRA analysis.

Only moderate, high, and severe risk levels were applied for the purposes of the

CRA analysis.

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6. RISK ANALYSIS RESULTS

This section presents the results of the CRA, including the information utilized to compile the

applicable cost contingency for this project. Additional details behind the CRA are found in

Appendix A of this report.

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

typical risk events studied (high and moderate levels) is presented in Table 1. This risk register

reflects the results of risk factor identification and assessment, risk factor quantification, and

contingency analysis.

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, are further refined, especially on large projects.

Recommended uses of the risk register going forward include:

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.

CRA team concerns.

CRA team discussions.

Project cost likelihood, impact, and risk level.

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Descriptions of Risk Items Associated with the LCA ARDC

Modification Project

Pipeline contractors who would have the equipment and training to do projects such as this

would not be interested in such a small project if other larger and more lucrative pipeline projects

are available. But, if there are no other projects available, it might be done for less money.

CA-1 Acquisition Strategy Decreasing Competition

Low: Guidance was provided by the Cost DX team to use a -10% cost impact for this risk item.

Likely: It is assumed that the likely scenario would result in an adequate amount of interested

bidders for this project.

High: Guidance was provided by the Cost DX team to use a +20% cost impact for this risk

item.

If specifications are too rigid and the contractor expends significant effort to meet rigid

specifications while trying to maintain a rigid time frame, this could increase project cost.

T-1 Unusual Specifications

Low: The lowest potential cost would be assuming that the contractor constructed the channels

properly, without adding extra manpower or effort to paying undue attention to slopes.

Likely: The most likely case is that the contractor will understand and do this appropriately.

High: There is a chance that the contractor would add extra manpower or equipment to ensure a

slope that was unnecessary. This would most likely be accomplished by utilizing an extra

excavator during the earthmoving phase of construction to properly compact the slopes. It is

estimated they this would require an additional expenditure for 1,300 hours of equipment rental

($512,404).

Special equipment is required to work in swamp areas. If pipeline contractors are busy with

other work, equipment may be harder to come by. On the other hand, if no other projects are

creating a demand for this equipment, it may be cheaper than normal.

C-7 Special Equipment and Equipment Availability

Low: It was assumed that the market price for the amphibious excavators would be decreased

by 10% ($51,240)

Likely: It is assumed that there would be adequate availability for amphibious equipment to

work on the earthmoving phase of the project.

High: It was assumed that the market price for the amphibious excavators would be increased

by 40% ($204,962).

C-8 In-Water Work

Working in water lends itself to risks that are not inherent on land, and must be considered as a

part of determining risks for this project. These risks are quantified in reductions in productivity

and in additional bond/insurance requirements for the contractor.

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Low: It was assumed that the low and most likely cost impacts would be the same.

Likely: It was assumed that the contractor would have adequate experience with in-water work

and would not require an additional markup to accommodate the risk associated with this type of

work.

High: It was assumed that an additional insurance markup would be added for the prime

contractor of 20% ($748,063).

C-10 Vegetative Planting Mortality

Tree mortality would result in additional costs for the project to ensure that an adequate number

of trees are added in the highly-degraded areas of the swamp and dredged material placement

areas.

Low: It is assumed that a reduction in vegetative plantinging of 10% would be required for the

designated areas at $3,301 per acre (10% of 443 acres = 44 less acres of planting).

Likely: It is assumed that the 50% secondary plantings will be adequate to achieve the required

tree densities.

High: It is assumed that an additional planting of 25% would be required for the designated

areas at $3,301 per acre (25% of 443 acres = 111 additional acres of planting).

If contract modifications, such as increased quantities and design modifications, are made during

project construction, it could cause unexpected costs. The contractor could need additional

manpower or equipment to accommodate these changes within the predetermined schedule.

C-11 Potential Contract Modifications

Low: Per previous risk analysis, the accepted most likely amount of Mods / Claims typically

adds 2% to 5.5% to overall project cost, used the low of 2%.

Likely: It is anticipated that no contract modifications will be required and therefore, there

would be no additional costs resulting from this risk item.

High: Per previous risk analysis, the accepted most likely amount of Mods / Claims typically

adds 2% to 5.5% to overall project cost, used the high of 5%.

Given the unique nature of this project, as well as the challenging terrain, it is likely that some

elements will be underestimated or not taken into consideration. It is also possible for the same

reasons that costs have been incorrectly overstated. This could lead to increased overall

construction costs resulting from the unanticipated or miscalculated cost items.

ES-1 Estimate Captures Scope for All Project Features

Low: It is anticipated that the total project cost would be the same as in the most likely

scenario.

Likely: It is anticipated that the current project cost estimates include all pertinent cost items for

this project.

High: It is anticipated that the total project cost would increase by approximately 10%

($187,016) due to unforeseen or miscalculated project features.

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Given that private property is involved in this project, it is possible for complications to arise,

which could lead to additional design or construction considerations.

E-1 Stakeholders Request Late Changes

Low: It is anticipated that there would only be significant cost impacts due to this risk item,

therefore no low impact would occur.

Likely: Due to the continued coordination with local landowners within the study area, it is

likely that no changes will result from stakeholder requests.

High: It is anticipated that changes that result from stakeholder requests would result in a

realignment of the conveyance channels or the addition of sheet piles along the cuts in the

dredged material berms. This would result in a cost risk of approximately 10% of the total

project costs ($374032).

An unexpected rise or fall in the cost of off-road diesel could have a significant effect on the cost

of this project.

E-5 Unexpected Escalation on Key Materials (Off-Road Diesel)

Low: The five year low for this area is $1.58 a gallon for off-road diesel and $1.98 for on-road

diesel (30% decrease). This reduction in fuel costs was determined unlikely, so a conservative

reduction of 15% was used ($1.92/2.31).

Likely: Current average on-road/off-road diesel fuel prices are $2.72/2.26 a gallon. It has been

determined that this will likely remain unchanged.

High: The five year high for this area is $4.80 a gallon (76% increase), which was a result of

hurricane Katrina. It is not believed that an increase of this significance will not occur, so a

conservative estimate of a 35% increase was used for off-road and on-road diesel ($3.05/3.67).

Hurricanes regularly strike Louisiana, and would create a significant delay and increase in price

if one struck during the course of the project. Flooding on the Amite River is a possibility as

well.

E-7 Acts of God (seismic events: volcanic activity, earthquakes, tsunamis; or severe

weather: freezing, flooding or hurricane)

Low: It is anticipated that the low cost impacts resulting from this risk item would be

insignificant to the overall cost of the project.

Likely: It is anticipated that there will not be a cost impact to the project costs as a result of this

risk item.

High: It is anticipated that the most significant impact to the project costs, resulting from a

tropical storm or hurricane, would be approximately 5% of the overall project costs ($187,015).

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Table 1. Summary Risk Register

Likelihood* Impact* Risk Level*

Minimum Likely

Cost ($)

Most Likely

Cost ($)

Maximum

Likely Cost ($)

Variance

Distribution

(Cost)

CA-1 Acquisition strategy decreasing competition Unlikely Critical Moderate $ 2,331,882.00 $ 2,590,980.00 $ 3,109,176.00 Triangular

T-1 Unusual Specifications Likely Marginal Moderate $ 2,590,980.00 $ 2,590,980.00 $ 3,103,384.00 Triangular

C-7 Special equipment and equipment availability Unlikely Significant Moderate $ 2,331,882.00 $ 2,590,980.00 $ 3,627,372.00 Triangular

C-8 In-water work Likely Marginal Moderate $ 2,590,980.00 $ 2,590,980.00 $ 3,109,176.00 Triangular

C-10 Vegetative planting mortality Likely Marginal Moderate $ 2,569,406.00 $ 2,590,980.00 $ 2,645,404.00 Triangular

C-11 Potential contract modifications Unlikely Significant Moderate $ 2,642,799.60 $ 2,590,980.00 $ 2,720,529.00 Triangular

ES-1 Estimate captures scope for all project features. Likely Significant High $ 2,590,980.00 $ 2,590,980.00 $ 2,850,078.00 Triangular

E-1 Stakeholders request late changes Unlikely Significant Moderate $ 2,590,980.00 $ 2,590,980.00 $ 2,850,078.00 Triangular

E-5 Unexpected escalation on key materials Unlikely Significant Moderate $ 2,202,333.00 $ 2,590,980.00 $ 3,497,823.00 TriangularE-7

Acts of God (seismic events: volcanic activity,earthquakes, tsunamis; or severe weather: freezing,flooding or hurricane)

Likely Marginal Moderate $ 2,590,980.00 $ 2,590,980.00 $ 2,720,529.00 Triangular

Project Cost

Risk

No.

Risk/Opportunity Event (logic by

feature, contract, responsibility)

*Likelihood, Impact, and Risk Level to be verified through market research and analysis1. Risk/Opportunity identified with reference to the Risk Identification Checklist and through2. Concerns and Discussions elaborate on Risk/Opportunity Events and includes any3. The responsib11. Results of the risk identification process are studied and further developed by the Cost

ility or POC is the entity responsible as the Subject Matter Expert (SME) for

4. Likelihood is measured as likelihood of impacting cost or schedule.5. Impact is a measure of the event's effect on project objectives with relation to scope, cost,6. Risk Level is the resultant of Likelihood and Impact Low, Moderate, or High. Refer to the matrixlocated at top of page.7. Variance Distribution refers to the behavior of the individual risk item with respect to its8. Correlation recognizes those risk events that may be related to one another. Care should be9. Affected Project Component identifies the specific item of the project to which the risk directly10. Project Implications identifies whether or not the risk item affects project cost, project

Contract Acquisition Risks

Estimate RisksExternal Risks

Construction Risks

Technical Risks

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6.2 Cost Risk Contingency Results

The results of the CRA were generated by Crystal Ball are found in Table 2 and Figures 1 though

4.

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Table 2. Crystal Ball Data and Results

Minimum Likely

Cost ($)

Most Likely

Cost ($)

Maximum Likely

Cost ($) Low Likely High Percentiles Forecast

$2,331,882.00 $2,590,980.00 $3,109,176.00 $2,331,882.00 $2,590,980.00 $3,109,176.00 0% 2,302,767$2,590,980.00 $2,590,980.00 $3,103,384.00 0 0 512,404 10% 3,126,173$2,331,882.00 $2,590,980.00 $3,627,372.00 -259,098 0 1,036,392 20% 3,301,339$2,590,980.00 $2,590,980.00 $3,109,176.00 0 0 518,196 30% 3,455,211$2,569,406.00 $2,590,980.00 $2,645,404.00 -21,574 0 54,424 40% 3,572,314$2,590,980.00 $2,590,980.00 $2,720,529.00 0 0 129,549 50% 3,695,451$2,590,980.00 $2,590,980.00 $2,850,078.00 0 0 259,098 60% 3,817,506$2,590,980.00 $2,590,980.00 $2,850,078.00 0 0 259,098 70% 3,955,670$2,202,333.00 $2,590,980.00 $3,497,823.00 -388,647 0 906,843 80% 4,110,994$2,590,980.00 $2,590,980.00 $2,720,529.00 0 0 129,549 90% 4,381,892

2,590,980 100% 5,283,051

Contingency = 59%

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Figure 1. Frequency Results

Figure 2. Cumulative Frequency Results

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Figure 3. Cumulative Sensativity Results

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Figure 4. Sensativity Bar Chart

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7. MAJOR FINDINGS/OBSERVATIONS

The CRA results presented a cost contingency of 59 percent at a confidence level of 80 percent.

This contingency does not include escalation cost, which are to be applied within the MicroComputer Aided Cost Estimating Software (MCACES) estimate for the recommended plan

(Alternative 33) upon determination of the applicable contingency cost. 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 progress through planning and implementation. Because of the potential

for use of risk analysis results for such diverse purposes, this section also reiterates and

highlights important steps, logic, key assumptions, limitations, and decisions to help ensure that

the risk analysis results are appropriately interpreted.

8. MITIGATION RECOMMENDATIONS

Based on the findings of this analysis, a 59 percent contingency will be applied to the MCACES

estimate for the recommended plan (Alternative 33). An Agency Technical Review will be

performed in February, 2010 at which time comments will be addressed and the results of this

analysis will be updated. The analysis performed by the CRA team, highlighted the potential

risks inherent to the Amite River Diversion Canal Modification project. The results of this

analysis not only help to quantify the financial risks involved with the recommended plan

(Alternative 33), but they also allow the study and design team plan for these risks in an effort to

mitigate the associated cost and schedule ramifications. Therefore, the following

recommendations are suggested:

The scope of work for all portions of this project must be clearly defined, in an effort to

minimize the chances of additional costs during construction and data analysis.

The scope should also be clearly defined during all aspects of cost analysis during the study

portion of this project.

Additional emphasis needs to be placed on the plans and specifications portion of the project to

ensure that the work is completed in a manor stipulated by the feasibility report and the design

process.

All efforts must be made to ensure that an optimal amount of tree plantings associated with the

construction of the project will succeed and therefore will not need to be replanted at a later time.

All issues involved with the mobilization and demobilization of this project must be well thought

out during the plans and specifications portion of this project, due to the remote nature of the

study area. This issue should also be heavily studied during the cost estimating phase of the

feasibility study.

Additionally, adequate staging areas must be provided during construction to allow for the timely

transport of equipment and personnel into and out of the construction site.

1347
16

An emphasis must be placed on construction sequencing during the plans and specifications

portion of the project to ensure the most efficient use of equipment and personnel possible during

construction.

All efforts must be made to attract an adequate amount of bidders during the bidding process to

ensure a competitive estimate is selected.

The appropriate estimations of weather disruptions must be made during the construction

scheduling process to limit any additional cost that may result from prolonged work stoppages.

1348
Section 11

SCHEDULE FOR DESIGN

AND CONSTRUCTION

1349

11-1

Design and Construction Schedule

A schedule will be developed for the required design, planning and construction needed

for the LCA-ARDC Modification project once a signed Chief’s Report is obtained in

December, 2010. It was assumed that these processes would begin in January 2011. The

schedule includes the following items:

• Plans & Specifications. This would involve the design phase of the project in

which a formalized plans and specifications package is produced for any

contractor willing to bid on the construction phase of the project. It is estimated

that this process would take approximately a year.

• Contract Acquisition. This process would include the development of a contract

for construction as well as the bidding and selection process. It is estimated that

this process would take approximately three months.

• Construction (Earthwork). This represents the portion of construction required

for construction of the bank openings and the bifurcated conveyance channels.

This would also include any necessary mobilization and demobilization.

Vegetative plantings are not included in this portion of the schedule. This process

is estimated to take approximately six months.

• Site Assessment/Planting Survival Assessment. Upon completion of the

earthmoving phase of construction a period of no activity would to take place to

allow for evaluations of existing vegetative conditions, before vegetative

plantings may commence. This allows for time to develop the scope of plantings,

acquire the needed plants and seedlings for planting, and to allow the placed

dredged material to settle. A similar assessment phase will be entered

approximately 8 months after the first planting has been completed.

• Vegetative Planting Contract Acquisition. This process would include the

development of a contract for vegetative plantings as well as the bidding and

selection process. It is estimated that this process would take approximately three

months. This process would most-likely be initiated twice, once for the initial

plantings and a few years later for the secondary plantings.

• Primary and Secondary Planting Contracts. This process is composed of the

initial and the secondary plantings of seedlings and potted plants in the designated

areas of the project footprint. This includes mobilization and demobilization,

planting, and the installation of nutria guards on each plant. It is estimated that

this process would take approximately 12 months.

1351
11-2

Table 1. Earthmoving Schedule

  	
 
 









	
 










   

  
 

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1352
ID Task Name

1 Plans & Specifications2 Contract Acquisition3 Construction (Earthwork)4 Site Assessment5 1st Vegetation Planting Contract Acquisition6 1st Acquisition of Trees7 1st Vegetation Planting Contract8 Planting Survival Assessment9 2nd Planting Contract Acquisition

10 2nd Acquisition of Trees11 2nd Planting Contract

Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May

2011 2012 2013 2014

TaskProgress

MilestoneSummary

Rolled Up TaskRolled Up Milestone

Rolled Up ProgressSplit

External TasksProject Summary

Group By SummaryDeadline

Page 1

Project: ALternative (TSP)Date: Thu 8/12/10

1353
ID Task Name

1 Plans & Specifications2 Contract Acquisition3 Construction (Earthwork)4 Site Assessment5 1st Vegetation Planting Contract Acquisition6 1st Acquisition of Trees7 1st Vegetation Planting Contract8 Planting Survival Assessment9 2nd Planting Contract Acquisition

10 2nd Acquisition of Trees11 2nd Planting Contract

Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar

2015 2016 2017 2018

TaskProgress

MilestoneSummary

Rolled Up TaskRolled Up Milestone

Rolled Up ProgressSplit

External TasksProject Summary

Group By SummaryDeadline

Page 2

Project: ALternative (TSP)Date: Thu 8/12/10

1354
Section 12

RELOCATIONS

1355

F

Relocations

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1357

Appendix M

HTRW REPORT

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1363