Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 1

CHAPTER 4 ENVIRONMENTAL CONSEQUENCES 

This chapter describes the potential environmental consequences of implementing alternative 

plans considered for wetland creation and nourishment and shoreline protection along the 

MRGO and Lake Borgne critical land bridge. The following analysis compares the No-Action 

Alternative to three alternatives carried over for detailed analysis: Alternative Plans 2, 3, and 

10. Alternative 10 is the Selected Plan (SP). Wetland creation and nourishment and shoreline 

protection alternatives are described in CHAPTER 2 ALTERNATIVES. 

A comparison of the direct, indirect, and cumulative impacts for wetland creation and 

nourishment, and shoreline protection opportunities is presented herein. Direct impacts are 

those effects that are caused by the proposed action and occur at the same time and place 

(Section 1508.8(a) of 40 CFR Parts 1500-1508). For example, the use of excavated borrow 

material would be used directly to create acres of emergent wetland habitat. Indirect impacts 

are those effects that are caused by the action and are later in time or further removed in 

distance, but are still reasonably foreseeable (Section 1508.8(b) of 40 CFR Parts 1500-1508). 

For example, shoreline protection features reduce the long-term rate of erosion to interior 

wetlands. Cumulative impacts would be the aggregate of impacts to the environment resulting 

from the proposed action in combination with other ongoing actions, and actions being 

considered within the reasonably foreseeable future. Cumulative impacts are the effects on the 

environment that results from the incremental impact of the action when added to other past, 

present, and reasonably foreseeable future actions, regardless of what agency (Federal or nonFederal) or person undertakes such actions. Cumulative impacts can result from actions that 

individually are minor, but collectively result in significant actions taking place over time 

(Section 1508.7 40 CFR Parts 1500-1508). For example, the incremental impacts of emergent 

wetland creation at several localized areas could significantly modify an entire basin’s habitat 

diversity. The cumulative impact analysis followed the 11-step process described in the 1997 

report by the Council of Environmental Quality entitled “Considering Cumulative Effect Under 

the National environmental Policy Act.” Table 4.1 summarizes cumulative impacts for all 

important resources. 

This environmental analysis evaluates and compares, from a qualitative and quantitative 

perspective, the three alternatives carried over for detailed analysis. Impact analysis described 

in this chapter is based on a combination of scientific and engineering analyses, professional 

judgment, and previously compiled information.
Chapter 4 

FEIS 

4 – 2

Table 4.1 Comparison of Cumulative Impacts* 

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Soils 

US: Institutional recognition of importance of soils with formation of Soil Conservation Service later to become Natural Resources Conservation Service. LA: Louisiana coastal land loss of over 1.22 million acres since 1956. PAA: Decline of 9,459 acres since 1956 from 31,071 acres to 21,612 acres (USGS). 

US: Natural processes of parent material, climate, organisms, relief, and time factors in soil formation. LA: Continued land loss of over 25 square miles per year. PAA: Continued decline of land area due to natural and human-induced causes. 

US & LA: Continued institutional recognition; continued loss of soil resources. PAA: Shoreline erosion and land loss would persist throughout resulting in the loss of soil resources. Over the 50-year period of analysis, there would be a projected loss of 9,850 acres at a rate of 197 acres per year. 

US & LA: Continued instituprograms for soil conservatioALT 10 (SP): This alternatisynergistic effects on soil resother Federal, state, local, anincluding the CWPPRA PO-Borgne shoreline protection. wetland soils would be proteALT 2: Cumulative impacts total of 2,264 of wetland soiland nourished. ALT 3: Cumulative impacts total of 2,284 acres of wetlancreated and nourished. 

*Includes Spatial/Geographic Extent (Continental United States [U.S.], Louisiana [LA], and Project Area [PAA], and Temporal (Past, Present, and Future with the No-Action Alternative). This cumulative impact analysis follows the 11-step process described in ththe Council of Environmental Quality entitled “Considering Cumulative Effect Under the National Environmental Policy Act.”
Chapter 4 

FEIS 

4 – 3

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Coastal Vegetation Resources 

U.S., LA & PAA: Natural Processes form coastal vegetation resources. In 1956, there were 30,616 acres of nonfresh marsh in the project area. A decrease in wetland acreage and shift to more saline marshes occurred since then, with 22,961 acres of brackish marsh in 1978, and 12,871 & 10,689 acres each of brackish and saline marshes in 1988. This was accompanied by the loss of other vegetation types in the project area; 34 acres of forest, 16 acres of swamp, and 12 acres of scrub/shrub habitat were lost since 1956. 

U.S. & LA: Deterioration and loss of wetlands nationwide and statewide. PAA: About 13,328 acres of brackish marsh and 7,627 acres of saline marsh presently occur within the project area. Wave action continues to erode the banks of the MRGO and the Lake Borgne shoreline. Saltwater intrusion has caused land loss and conversion of fresh marsh and swamp to brackish and salt marsh, but this process has stabilized somewhat in recent years. 

U.S. & LA: Continued deterioration and loss of vegetated wetland habitat acreage due to natural and human-induced processes. PAA: Continued degradation and loss of existing wetland vegetative habitats, in concert with truncation of replenishing processes would accelerate declines in the interdependent processes of plant production and vertical maintenance necessary for persistence of a stable ecosystem. Reduced erosion along the MRGO bankline due to deauthorization of channel. There would be an expected 9,850 acres of wetlands lost from the PAA at a rate of 197 acres per over the next 50 years. Closure structure at Bayou La Loutre may result in a shift from saline marsh to brackish marsh in southern half of project area. 

U.S. & LA: Implementing treduction to the rate of loss oALT 10 (SP): This alternatisynergistic effects on coastal combined with other Federalrestoration efforts, including 

and ongoing Lake Borgne shof 2,162 acres of brackish anprotected, created and nourisin the stabilization of the lanshoreline erosion. The potenproductive marshes to accretequal to local sea level rise, subsidence may also be reduenhanced wetland acreage wecosystems inland from the sloss rates. ALT 2: Cumulative impacts (SP). A net total of 2,264 acmarsh would be protected, cALT 3: Cumulative impacts (SP). A net total of 2,284 acmarsh would be protected, c
Chapter 4 

FEIS 

4 – 4

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Wildlife Resources 

U.S., LA & PAA: Wetland dependent wildlife populations respond primarily to natural populationregulating mechanisms. 

U.S., LA: Continued nationwide degradation and loss of wetlands leads to decline of wetlanddependent wildlife populations. PAA: Continued wetland degradation and loss in the MRGO area leads to increased competition between local wetlanddependent wildlife populations for decreasing resources; displacement to other more suitable wetland areas; and localized decline in wetland-dependent wildlife population. 

U.S., LA: Nationwide degradation and loss of wetlands continues to adversely impact wetlanddependent wildlife populations. PAA: An expected 9,850 acres of wetlands lost from the PAA at a rate of 197 acres per year over the next 50 years. Leads to increased competition between local wetlanddependent wildlife populations for decreasing resources; displacement to other more suitable wetland areas; and localized decline in wetland-dependent wildlife population. 

U.S., LA: Continued nationcontinues to adversely impacpopulations. ALT 10 (SP): This alternatisynergistic effects on wildlifwith other Federal, state, locefforts, including the CWPPLake Borgne shoreline proteprotect, create and nourish a important and essential wildneotropical songbirds and wuse of the project area as critprotected, created and nourisimpact wildlife populations opopulations of game animalsamphibians, and invasive spebenefit from the cumulative and nourishing important anwetlands. ALT 2: Cumulative impacts (SP), except this alternative 

nourish a net total of 2,284 aALT 3: Cumulative impacts (SP) except this alternative wnourish a net total of 2,264 a
Chapter 4 

FEIS 

4 – 5

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Fishery Resources 

U.S. & LA: Reduction in fisheries habitat while catches increased. Formation of the National Marine Fisheries Service. PAA: Construction of the MRGO resulted in saltwater intrusion into previously freshwater & brackish environments leading to more marine fishery species. 

U.S. & LA: Regulated catch; habitat loss decreased somewhat by coastal restoration efforts; continued net habitat loss. About 90% of the world's seafood resources have been depleted in the past century; 38% of the depleted species have declined by more than 90 percent; 7% of the species of fish studied by researchers have become extinct (Worm et al., 2006). PAA: Fishery population changes associated with the distribution and structure of coastal marsh vegetative communities, which are shallow-water habitat for migratory and resident estuarine-marine and marine species of fish. 

U.S., LA & PAA: Continued loss of fishery resources unless intensified efforts to protect them locally, statewide, and nationally. 

U.S. & LA: Continued loss 

intensified efforts taken to prand nationally. ALT 10 (SP): This alternatisynergistic effects on fishery other Federal, state, local, anincluding the CWPPRA PO-Borgne shoreline protection. create and nourish a net total and essential transitional weresources for spawning, foralife requirements. Localized important fishery habitats coincreased productivity. ALT 2: Cumulative impacts (SP) except this alternative wnourish a net total of 2,284 atransitional wetland habitats spawning, foraging, cover, nrequirements, ALT 3: Cumulative impacts (SP) except this alternative wnourish a net total of 2,264 atransitional wetland habitats spawning, foraging, cover, nrequirements. 
Chapter 4 

FEIS 

4 – 6

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Plankton Resources 

U.S., LA & PAA: Populations respond to natural conditions. 

U.S.: Populations respond to natural and human-induced perturbations. LA & PAA: Populations in portions of the state and in the PAA are shifting towards more saline-dominant species as land loss and saltwater intrusion into interior regions continues. 

U.S.: Populations continue to respond to natural and human-induced perturbations. LA & PAA: Increased land loss and saltwater intrusion would lead to more saline adapted populations. 

U.S. & LA: Plankton populanatural and human-induced pALT 10 (SP): This alternatisynergistic effects on planktowith other Federal, state, locefforts, including the CWPPLake Borgne shoreline protecreation and nourishment wofor phytoplankton and zoopldissolved organic compoundwetlands. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 

Water Bottoms and Benthic Resources 

U.S., LA & PAA: Water bottoms develop in response to natural conditions. Benthic populations respond to natural conditions. 

U.S., LA & PAA: Increased acreage of shallow water bottoms in response to wetland loss. Benthic populations respond to natural and human-induced perturbations. PAA: Benthic populations shift towards more salinedominant species as land loss and saltwater intrusion into interior regions continues. 

U.S., LA & PAA: Increased acreage of shallow water bottoms in response to wetland loss. Benthic populations respond to natural and human-induced perturbations with shift towards more salinedominant species as land loss and saltwater intrusion into interior regions continues. PAA: Benthic populations shift towards more salinedominant species as land loss and saltwater intrusion into interior regions continues. 

U.S. & LA: Increased acrearesponse to wetland loss. Benatural and human-induced pmore saline-dominant specieintrusion into interior regionALT 10 (SP): This alternatisynergistic effects on benthic with other Federal, state, locefforts, including the CWPPLake Borgne shoreline protecreation and nourishment wofor benthic organisms due to compounds and detritus from acres of Lake Borgne water provide material for wetland ALT 2: Cumulative impacts (SP), except that up to 1,070 bottoms would be dredged to creation and nourishment. ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 7

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Essential Fish Habitat (EFH) 

U.S., LA & PAA: General decrease in quality of EFH beginning in the mid 1900s. Institutional recognition of decline in EFH quality; passage of MagnusonStevens Fishery Conservation and Management Act. 

U.S. & LA: Continued institutional recognition; continued wetland loss and decline in quality of EFH. PAA: CWPPRA shoreline protection projects such as PO-30 and other restoration projects protect some existing EFH. Continued wetland loss converts highquality EFH to lower quality categories (e.g., emergent wetlands to open water bottoms). 

U.S. & LA: Continued institutional recognition; continued wetland loss and decline in quality of EFH. PAA: Continued conversion of existing wetlands to shallow open water habitats; continued shoreline erosion contributes to decline in quality of EFH, especially nursery habitat. 

U.S. & LA: Continued instioverall decline in quality of maintain productive forms osupport Federally-managed sALT 10 (SP): This alternativsynergistic effects on EFH wFederal, state, local, and privincluding the CWPPRA PO-Borgne shoreline protection. and nourishment for a net tothe conversion of transitionaespecially inner marsh and mfor brown shrimp, white shridecrease the vulnerability of of EFH (e.g., shallow open wexpected convert to lower quALT 2: Cumulative impacts (SP). A net total of 2,264 ac

provide higher quality EFH. ALT 3: Cumulative impacts (SP). A net total of 2,284 acprovide higher quality EFH. 
Chapter 4 

FEIS 

4 – 8

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Endangered and Threatened Species 

U.S.: Institutional recognition of decline in listed species via the Endangered Species Act. LA & PAA: Decrease in some animal and plant populations and their critical habitat including loss of wetlands. 

U.S.: Continued loss of wetlands. LA & PAA: Continued loss of wetlands that are critical habitat to many listed species. 

U.S.: Continued institutional recognition of decline in listed species; continued loss of wetlands. LA & PAA: Continued coastal land loss and deterioration of critical coastal habitats is anticipated to impact all listed species that utilize them. 

U.S. & LA: Continued instiin listed species; continued lALT 10 (SP): This alternatisynergistic effects on listed sother Federal, state, local, anincluding the CWPPRA PO-Borgne shoreline protection. action would involve activitiGulf sturgeon, the scope of ato Adversely Affect (NLAAand its critical habitat in Lakto listed species would be reof all past, present, and futurAlternative 10 (SP) would prtotal of 2,162 acres of imporwould provide transitional wforaging, nursery, spawning ALT 2: Cumulative impacts (SP) except this alternative wnourish a net total of 2,264 aALT 3: Cumulative impacts (SP) except this alternative wnourish a net total of 2, 284 
Chapter 4 

FEIS 

4 – 9

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Hydrology Resources – Flow and Water Levels 

U.S., LA & PAA: Flows and water levels respond to natural conditions. 

U.S. & LA: Increased flows and water levels with increased runoff due to increasing urbanization and wetland loss. Rate of relative sea level rise increasing over historic conditions. PAA: Increased flows and water levels due to construction of the MRGO, coastal wetland loss, and increased runoff due to increased urbanization of the Pontchartrain Basin. 

U.S. & LA: Increased flows and water levels with increased urbanization and associated runoff and increased wetland loss. Rate of relative sea level rise increasing over historic conditions. PAA: Increased flows and water levels due to coastal wetland loss, and increased runoff due to increased urbanization of the Pontchartrain Basin. Degradation and breaching of the land bridge between Lake Borgne and MRGO anticipated to increase tidal exchange between the two waterbodies. Closure of the MRGO channel at Bayou La Loutre anticipated to reduce tidal exchange between Lake Borgne and Breton Sound. 

U.S. & LA: Increased flows increased urban runoff from increased wetland loss. Rate increasing over historic condALT 10 (SP): This alternatiand water levels similar to thexcept that protection of the breaches between Lake Borgforming and enlarging. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 

Hydrology Resources – Sediments 

U.S.: Decreasing sedimentation due to reduction of erosion on land, reservoirs, and bank stabilization. LA & PAA: Sediment delivery by crevasses ended after 1928- flood control act. 

U.S.: Decreasing sedimentation due to reduction of erosion on land, reservoirs and bank stabilization. LA & PAA: Inflow of suspended sediments by Mississippi River limited by construction of levees. PAA: Some redistribution of sediments by flows from Lake Borgne during storms. 

U.S.: Continued decreasing sedimentation due to reduction of erosion on land, reservoirs and bank stabilization. LA: Sediment supply does not offset coastal land loss. PAA: Some redistribution of sediments from Lake Borgne during storms. 

U.S. & LA: Continued decrreduction of erosion on landstabilization. ALT 10 (SP): Construction would redistribute 9.7 milliothe Lake Borgne water bottocreate and nourish wetlands. 

expected to refill over time. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 10

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Water Quality 

U.S. & LA, PAA: Water quality generally not an issue in historic times. PAA: There are no human communities in PAA and no water quality issues. 

U.S. & LA: Institutional recognition of water quality issues (e.g., Clean Water Act) to restore and protect waterbodies, especially with respect to point sources. Non-point sources still unregulated. PAA: Wastewater and polluted runoff from urban areas enter the MRGO and Lake Borgne from many sources. Both total and fecal coliform consistently exceed the applicable criteria. Continued loss of emergent wetlands impacts the marshes ability to absorb and reduce air and water pollutants. 

U.S., LA & PAA: Continued institutional recognition; increasing human populations and industrialization result in increased potential for water quality problems. PAA: Increasing human populations and industrialization result in increased potential for water quality problems. Increased potential for accidental discharges due to exposed infrastructure caused by coastal wetland loss. 

U.S. & LA: Continued insti

human populations and indupotential for water quality prALT 10 (SP): This alternatisynergistic effects on water qother Federal, state, local, anincluding the CWPPRA PO-Borgne shoreline protection. by nourishing, creating, and improve the overall water quALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 

Recreation Resources 

U.S. & LA, PAA: Not an issue. 

U.S. & LA: Increased recreational activities impact national and state wetlands. PAA: Wetland degradation and loss resulting in decreasing recreation opportunities. 

U.S., LA & PAA: Potential loss of recreational resource base due to continued coastal and wetland degradation and loss. 

U.S. & LA: Potential loss of to continued coastal and wetALT 10 (SP): This alternatisynergistic effects on recreatwith other Federal, state, locefforts, including the CWPPLake Borgne shoreline protesupport and sustain a greater recreational opportunities, prlocalized recreation economyrecreation-related employmeALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 11

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Public Lands 

U.S.: Not an issue. LA, PAA: The establishment of the Bayou Sauvage National Wildlife Refuge (NWR) in 1990 set aside public lands in the Greater New Orleans area, some of which are in the PAA. 

U.S. & LA: Increased recreational activities impact public lands. PAA: Wetland degradation and loss resulting in decreasing opportunities for utilization of public lands. 

U.S., LA & PAA: Potential loss of opportunities due to continued coastal and wetland degradation and loss. 

U.S. & LA: Potential loss of coastal and wetland degradaALT 10 (SP): This alternatisynergistic effects on wetlanSauvage NWR when combinlocal, and private restoration create and nourish a total of near the Bayou Sauvage NWALT 2: Cumulative impacts (SP), except that 2,850 acres nourished in and near the BaALT 3: Cumulative impacts (SP), except that 2,750 acres nourished in and near the Ba

Historic & Cultural Resources 

U.S., LA & PAA: Institutional Recognition via National Historic Preservation Act (and others). Historic and cultural resources subjected to natural processes and manmade actions. 

U.S., LA & PAA: Human activities as well as natural processes can potentially destroy historic and natural resources. 

U.S. & LA: Potential loss of resources due to natural and human causes. PAA: The loss of land along the MRGO and Lake Borgne corridor threatens the existence and integrity of these resources. 

U.S. & LA: Potential loss of human causes. ALT 10 (SP): All types of sfurther land loss and erosion benefit cultural and historicaslowing or stopping land lostheir existence. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 12

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Aesthetics 

U.S., LA & PAA: Aesthetics not an issue. 

U.S., LA & PAA: Technical recognition via 1988 USACE Visual Resources Assessment Procedure. Institutional recognition via Wild and Scenic Rivers Act, Scenic Byways and others. Visual resources have been destroyed, enhanced, or preserved by human activities and natural processes. LA & PAA: Continued wetland loss may have an adverse effect on the visual complexity of the bayous and marshes. 

U.S. & LA: Continued human population growth and development and other human activities have the potential to destroy, enhance or preserve visual resources. PAA: Erosion and land loss could destroy portions of any existing remnants of Bayou La Loutre’s natural levees resulting in the loss of any vegetation that may provide a visually complex environment and desirable viewscapes. 

U.S. & LA: Continued humdevelopment and other humato destroy, enhance or preserALT 10 (SP): This alternatisynergistic effects on aesthetFederal, state, local, and privincluding the CWPPRA PO-Borgne shoreline protection. appealing resources systems travels Louisiana’s Scenic Bvisual interest. Restoration fcontiguous marsh, which wodesirable viewscapes. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 

Noise U.S., LA & PAA: Noise is not an issue. 

U.S. & LA: Institutional recognition-Noise Control Act of 1972. Continued human population growth and development causes some noise pollution. PAA: Ambient noise from boats, airboats and other human activities may cause some minimal and temporary disturbances in the project area. 

U.S. & LA: Continued institutional recognition; continued human population growth and development would cause some noise pollution. PAA: Ambient noise from boats, airboats and other human activities continue to cause some minimal and temporary disturbances in the project area. 

U.S. & LA: Continued instihuman population growth ansome noise pollution. ALT 10 (SP): The cumulatirelated to construction activibut minor, noise pollution thadditively interact with other and private restoration activiinduced noise disruptions in 

ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 13

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Air Quality U.S., LA & PAA: Not an issue. 

U.S. & LA: Institutional recognition via Clean Air Act; deterioration of air quality in the region due to increases in human populations and industry. PAA: Area remote and uninhabited, within Attainment. 

U.S., LA & PAA: Continued institutional recognition however, air quality would likely decline due to continued population growth and increased industrialization. These impacts would be coupled with the continued loss of Louisiana coastal wetland vegetation that would no longer be available to remove gaseous pollutants. 

U.S. & LA: Continued instiair quality would likely decligrowth and increased industrALT 10 (SP): This alternatisynergistic effects on air quaFederal, state, local, and privincluding the CWPPRA PO-Borgne shoreline protection. the potential improvement oof air pollutants by vegetatioreduction of air pollution. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 

Socioeconomic and Human Resources – Population 

U.S., LA & PAA: Not an issue. 

U.S.: Increasing population with over 300 million people. LA: Hurricanes Katrina and Rita adversely effects populations throughout the state. Some neighborhoods yet to be repopulated. PAA: Area remote and uninhabited. 

U.S. & LA: Increasing populations worldwide. PAA: There are no communities or populations within the project area. 

U.S. & LA: Increasing popuALT 10 (SP): There would populations. Population shifshoreline stabilization and mThe project area is not populwould be provided some, unsurge protection by protected

wetlands in the land bridge. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 14

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Socioeconomic and Human Resources – Infrastructure 

U.S. & LA: Increasing population growth and supporting infrastructure in the form of roads, bridges, pipelines, homes and businesses decreases coastal and other wetlands. PAA: Utilities and pipelines pass through project area. 

U.S.: Increasing population growth and supporting infrastructure contributes to degradation and loss of coastal and other wetlands. Degradation and loss of wetlands contribute to increased maintenance costs of infrastructure. LA: Extensive damages to infrastructure due to Hurricanes Katrina and Rita which is still being repaired. PAA: Utilities and pipelines pass through project area. 

U.S. & LA: Continued population growth and supporting infrastructure contributes to degradation and loss of coastal and other wetlands. Degradation and loss of wetlands contribute to increased maintenance costs of infrastructure. PAA: Wetland land loss potentially threatens infrastructure passing through area and results in increased maintenance. 

U.S. & LA: Continued popuinfrastructure contributes to and other wetlands. Degradacontribute to increased mainALT 10 (SP): This alternatisynergistic effects on infrastrother Federal, state, local, anincluding the CWPPRA PO-Borgne shoreline protection. 

level of infrastructure damagthe No-Action Alternative. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 

Socioeconomic and Human Resources – Employment and Personal Income 

U.S. & LA: Increased habitation, employment and tourism. PAA: Area remote and uninhabited. 

U.S.: Increasing population growth and employment and personal income opportunities. LA: Hurricanes Katrina and Rita have an adverse effect on employment and personal income. Rebuilding efforts providing some new job opportunities. PAA: Area remote and uninhabited. 

U.S. & LA: Increasing population growth and employment and personal income opportunities. Economic activity related to wetland resources would be aversely affected by the depletion of these resources. PAA: Area remote and uninhabited. 

U.S. & LA: Increased humacompetition for employment related to wetland resources the depletion of these resourALT 10 (SP): This alternatisynergistic effects on employcombined with other Federalrestoration efforts, including 

and ongoing Lake Borgne shimpacts of the proposed actiostability of the wetland resouLocal wetland-dependent jobcommercial fisheries, would some unknown extent. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 15

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Socioeconomic and Human Resources – Navigation 

U.S., LA & PAA: Navigation interests have historically been a critical factor to national, state, and local interests. Growth of port facilities and inland waterways and traffic. 

U.S., LA & PAA: Hurricanes Katrina and Rita impact navigation infrastructure and investments. Public and private reinvestment to rebuild navigation, port facilities, and inland waterways. Deauthorization of the MRGO channel to navigation by WRDA of 2007. 

U.S. & LA: Continued investment in port facilities and inland waterways. Navigation continues to be important part of the national transportation and commerce activities. PAA: Loss of critical Lake Borgne & MRGO land bridge subjects navigation along GIWW to more open marine influences. Deauthorization of the MRGO channel reduces vessel traffic along the MRGO. 

U.S. & LA: Continued inveinland waterways. Navigatioof the national transportation ALT 10 (SP): This alternatisynergistic effects on navigaFederal, state, local, and privincluding the CWPPRA PO-Borgne shoreline protection. protection of the portions of cargo that are located adjace

ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 

Socioeconomic and Human Resources – Oil, Gas and Utilities Pipelines 

U.S., LA & PAA: Development of extensive network of oil and gas pipelines in mid-1900s. 

U.S., LA & PAA: Increasing operations & maintenance costs as well as increasing investment for oil and gas production facilities and pipelines, due to increasing vulnerability of to widespread coastal wetland loss. 

U.S., LA & PAA: Increasing operations & maintenance 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. 

U.S. & LA: Increasing operwell as increasing investmenfacilities and pipelines, increand other infrastructure due loss. ALT 10 (SP): This alternatisynergistic effects on oil, gas combined with other Federalrestoration efforts, including 

and ongoing Lake Borgne shwould be a localized potentigas and utilities pipelines. Rwould also likely be reducedALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 16

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Socioeconomic and Human Resources – Commercial Fisheries 

U.S., LA & PAA: Increases in commercial fisheries industry, due to advancing technologies and increased fishing pressure. 

U.S., LA & PAA: Institutional recognition and regulation of commercial fisheries maintains a billion dollar industry. About 90% of the world's seafood resources have been depleted in the past century; 38% of the depleted species have declined by more than 90 percent; 7% of the species of fish studied by researchers have become extinct (Worm et al. 2006). PAA: Project area provides essential and critical habitat for important commercial fisheries. 

U.S.: Institutional recognition continues; commercial fisheries decline expected as overfishing and habitat degradation and loss continues unless concerted efforts to protect, restore, and regulate a sustainable industry. LA & PAA: Loss of commercial fisheries production due to loss of essential wetland habitats and salinity changes. 

U.S. & LA: Institutional recfisheries decline expected as degradation and loss continuprotect, restore, and regulate ALT 10 (SP): This alternatisynergistic effects on commewith other Federal, state, locefforts, including the CWPPLake Borgne shoreline protewould protect, create and no

that would provide EFH (i.eused for cover, foraging, nurrequirements). Localized imwould provide some, undetelocal commercial fisheries. ALT 2: Cumulative impacts (SP) except this alternative wnourish a net total of 2,264 aALT 3: Cumulative impacts (SP) except this alternative wnourish a net total of 2,284 a

Socioeconomic and Human Resources – Oyster Leases 

U.S., LA & PAA: General increase in acreage leased, production limited by saltwater intrusion in areas with no freshwater introduction. 

U.S., LA & PAA: Production has been stable for the last 50 years. Longterm sustainability threatened by reduction of marsh habitat. 

U.S.: Only major leasing program is in LA. LA & PAA: Production from leases would likely decline due to loss of habitat. 

U.S.: Only major leasing prLA: Production from leases of habitat. ALT 10 (SP): This alternatisynergistic effects on oyster other Federal, state, local, anincluding the CWPPRA PO-Borgne shoreline protection. only a small percentage of acproject site. ALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 

FEIS 

4 – 17

Significant 

Resource 

Past Actions 

(Historic Conditions) 

Present Actions 

(Existing Conditions) 

The No-Action 

Alternative 

(Future Without Project) 

Cumulat

(Comparison of Future W

Socioeconomic and Human Resources – Flood Control & Hurricane Protection Levees 

U.S. & LA: Flood of 1927 initiates national construction of hurricane and flood control levees, pump stations and control structures. Hurricanes Katrina and Rita cause significant widespread damages to existing hurricane and flood control structures. PAA: No hurricane or flood control structures in project area, but some are immediately adjacent. 

U.S. & LA: Largest national restoration effort of hurricane and flood control in nation’s history. PAA: No hurricane or flood control structures in project area, but some are immediately adjacent. 

U.S. & LA: As populations continue to migrate to coastal communities, increasing investment in hurricane and flood control levees, pump stations, and other flood control facilities. PAA: Continued degradation of wetlands will result in localized storm surge and storm waves increases. The Hurricane Protection Office is planning to construct a structure for flood protection in the western reaches of the Golden Triangle. 

U.S. & LA: As populations communities, increasing invcontrol levees, pump stationfacilities. ALT 10 (SP): This alternatisynergistic effects on flood clevees when combined with private restoration efforts, inproject, and ongoing Lake BMarsh creation and shoreline preserve and rebuild the marturn provide some protection structures immediately adjacALT 2: Cumulative impacts (SP). ALT 3: Cumulative impacts (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 18

4.1 SOILS 

4.1.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on soil resources. Existing conditions would persist, 

including the projected loss of about 9,850 acres (3,991 ha) of wetland soil resources in the 

project area over the 50-year period of analysis. Clovelly muck and Lafayette muck soil types 

would be primarily affected. Some Fausse clay soils would also be lost from the eastern and 

western extremes of the Lake Borgne shoreline. Net primary productivity within the project 

area would continue to decline and existing wetland vegetation would continue to diminish. 

The ongoing conversion of existing fragmented emergent wetlands to shallow open water would 

continue with associated indirect impacts on coastal vegetation, fish and wildlife resources, 

EFH, recreation, aesthetic, and socioeconomic resources. 

Other indirect adverse impacts that would result from the loss of important and essential 

vegetated habitats used by fish and wildlife are the loss of shelter, nesting, feeding, roosting, 

cover, nursery, and other life requirements for fish and wildlife; loss of productivity; loss of 

transitional habitat between estuarine and marine environments; and increased inter- and intraspecific competition between resident and migratory fish and wildlife species for decreasing 

wetland resources. This would also reduce the availability of important stopover habitats used 

by migrating neotropical birds. 

Cumulative impacts of the projected loss of about 9,850 acres (3,991 ha) of soil resources from 

the project area would be in addition to the loss of soil resources throughout Louisiana. The 

LCA Study (USACE, 2004) estimated coastal Louisiana would continue to lose land at a rate of 

approximately 6,600 acres per year (2,672 ha/year) over the next 50 years. It is estimated that 

an additional net loss of 328,000 acres (132,794 ha) may occur by 2050, which is almost 10 

percent of Louisiana’s remaining coastal wetlands. However, these wetland soil losses would 

be offset to some extent by other Federal, state, local, and private restoration efforts not only 

within the Pontchartrain and Breton Basins, but across coastal Louisiana (Table 4.2). 

In addition, more recent restoration efforts would also cumulatively interact to help offset losses 

of soil resources in the project area, including the following: 

y CWPPRA PO-30 Lake Borgne Shoreline Protection project. 

y The MRGO 2006 Lake Borgne Shoreline Protection, (Doulluts Canal to Jahncke’s 

Ditch), St. Bernard Parish, LA (06-C-0210) project. 

y The MRGO 2007 North Bank Foreshore Dike Construction and Repairs, Mile 44.4 to 

Mile 39.9 (Non-Continuous), St. Bernard Parish, LA (07-C-0089) project. 

y Passage of the WRDA 2007, which authorizes construction of several projects that 

would provide positive cumulative impacts in reducing the loss of soil resources 

throughout the project area including the following: 

y MRGO rock closure structure at Mile 36 that would help to restore and protect the 

ecosystem. 

y The LCA Plan near-term restoration features including the MRGO environmental 

restoration feature and the Violet Diversion feature. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 19

Table 4.2 Net Acres1 Created, Restored, and/or Protected by Other Federal, State, 

Local, and Private Restoration Efforts (USACE, 2004). 

 Subprovince 

1 

(acres) 

Subprovince 

2 

(acres) 

Subprovince 

3 

(acres) 

Subprovince 

4 

(acres) 

Totals 

(acres) 

Breaux Act 

CWPPRA1 33,690 44,913 25,057 30,486 134,146 

State 2,543 9,043 5,200 1,972 18,758 

PCWRP2 14 41 371 31 457 

Mitigation 

Civil Works 

Projects3

4,990 0 5,000 0 9,990 

Mitigation 

Regulatory 

Permits1

6,411 3,199 2,635 2,983 15,228 

Vegetation4 535 878 1,785 1,931 5,129 

Section 

204/1135, 

Beneficial Use 

226 414 1,293 3,525 5,458 

WRDA5 16,000 33,000 0 0 49,000 

Other6 0 2,000 50,000 3,226 426,132 

TOTALS 64,410 93,490 91,344 44,158 664,298 

Source: The state, parish, FEMA, vegetation, WRDA, Sections 204/1135, 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 includes 50,000 acres (20,250 ha) of 

non-mitigation land bought in fee in the Atchafalaya Basin by the District. 

1 – CWPPRA acreages are based upon 20-year project life; all other acreages are 50 years. 

2 – PCWRP = Parish Coastal Wetlands Restoration Program (“Christmas Tree Program”). 

3 – In the best-case scenario, compensatory mitigation (for civil works projects and regulatory permits) 

results in no net loss of wetlands. Hence, it is not the intent to imply that compensatory mitigation 

acreages would contribute to a net increase in wetlands as a result of the Clean Water Act Section 404 

program. Rather, these figures represent an accounting of the various cumulative impacts to coastal 

wetlands from Federal, state, local, and private restoration efforts. 

4 – Vegetation = LDNR/NRCS/Soil and Water Conservation Committee Vegetation Planting Program. 

5 – WRDA = Completed Federal Water Resources Development Act projects, including the Davis Pond and 

Caernarvon diversions. 

6 – Includes 30,558 acres (12,376 ha) restored and 340,348 (137,840 ha) acres enhanced by North American 

Wetlands Conservation Act (NAWCA), administered by the USFWS; unable to determine exact 

locations. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 20

4.1.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Compared to the No-Action Alternative, implementing the SP 

would significantly increase and protect soil resources in the project area. Utilizing 

approximately 9,700,000 cy (7,406,454 cubic meters) of Lake Borgne water bottoms, a total of 

3,345 acres (1,355 ha) of wetland soils would be created (1,675 acres/679 ha) and nourished 

(1,670 acres/677 ha). Shoreline protection features would prevent the erosion of 270 net acres 

(109 ha) of emergent wetland soils from the project area. These soils are mainly Clovelly muck 

and Lafayette muck, but some Fausse clay soils occur near the Bayou Bienvenue shoreline 

protection feature. Sediments used for wetland creation and nourishment would be subjected to 

different biogeochemical processes, and would, over time, begin to more closely resemble the 

Clovelly and Lafayette muck soils that they would be covering. Additionally, the sediments 

exposed in the borrow areas are expected to have a lower organic content than surface 

sediments, but would more closely resemble the existing Lake Borgne water bottom with time. 

Rock used for shoreline protection features would compress a total of 39.5 acres (16.0 ha) of 

Lake Borgne water bottom soils within the footprint of these features. A total of 118.3 acres 

(47.9 ha) of Lake Borgne water bottom soils would be dredged for floatation access, which 

would be used for wetland creation, to the maximum extent practicable, and thereby converted 

to emergent wetland-type soils. 

ALTERNATIVE 2: Direct impacts of Alternative 2 would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 2 would use 9,500,000 cy 

(7,235,743 cubic meters) of Lake Borgne water bottoms to create and nourish a total of 

2,850 acres (1,155 ha) of wetland soils. Shoreline protection features would prevent the erosion 

of 579 net acres (235 ha) of emergent wetland soils from the project area. The placement of 

ACM on the south bank of the MRGO would further compact 49.8 acres (20.2 ha) of existing 

soils. Rock used for shoreline protection features would compress a total of 74.0 acres (30.0 ha) 

of Lake Borgne water bottom soils within the footprint of these features. A total of 186.2 acres 

(75.4 ha) of Lake Borgne and MRGO water bottom soils would be dredged for floatation 

access, which would be used for wetland creation, to the maximum extent practicable, and 

thereby converted to emergent wetland-type soils. 

ALTERNATIVE 3: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 3 would use 11,400,000 cy 

(8,704,492 cubic meters) of Lake Borgne water bottoms to create and nourish a total of 

3,670 acres (1,487 ha) of wetland soils. Shoreline protection features would prevent the erosion 

of 380 net acres (154 ha) of emergent wetland soils from the project area. Rock used for 

shoreline protection features would compress a total of 47.2 acres (19.1 ha) of Lake Borgne 

water bottom soils within the footprint of these features. A total of 59.9 acres (24.3 ha) of Lake 

Borgne water bottom soils would be dredged for floatation access, which would be used for 

wetland creation, to the maximum extent practicable, and thereby converted to emergent 

wetland-type soils. 

4.1.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Compared to the No-Action Alternative, indirect impacts of 

implementing the SP on soil resources would be the creation, nourishment and protection of a 

net total of 2,162 acres (876 ha) of emergent wetland-type soils over the 50-year period of 

analysis. These soils are mainly Clovelly muck and Lafayette muck, but some Fausse clay soils 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 21

occur near the Bayou Bienvenue shoreline protection feature. A total of 9,700,000 cy 

(7,406,454 cubic meters) of borrow material would be dredged from 1,850 acres (750 ha) of 

Lake Borgne water bottoms for placement into wetland creation and nourishment sites. Borrow 

sites would be located a minimum of 3,000 ft (914 m) from the shoreline to minimize the 

potential for increased erosion, due to potential changes in the wave climate, of unprotected 

shorelines. 

Implementing the SP would help stabilize and maintain soil resources within the Lake Borgne 

and MRGO critical land bridge, thereby reducing the loss of soil resources from the project 

area. Other indirect impacts would be an increase in coastal vegetation resources and the reestablishment of transitional habitat, between estuarine and marine environments, that provides 

important and essential fish and wildlife habitat used for shelter, nesting, feeding, roosting, 

cover, nursery, and other life requirements. The in situ soil resources at the borrow sites would 

continue to be subjected to natural (e.g., high energy estuarine and marine forces) and manmade influences (e.g., oil and gas exploration and removal). The addition of soil resources to 

adjacent sediment-starved emergent wetlands would increase the opportunity for reestablishment of coastal vegetation that would further increase soil accretion. The interior 

wetland loss rate would be expected to decrease by 50 percent with the added soil stability 

derived from a more contiguous wetland (Louisiana Coastal Wetlands Conservation and 

Restoration Task Force, 2006). The estuarine water bottoms in the project area would continue 

to be utilized by benthic organisms. 

ALTERNATIVE 2: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 2 would create, nourish and 

protect a net total of 2,264 acres (917 ha) of emergent wetland-type soils over the 50-year 

period of analysis. A total of 9,500,000 cy (7,253,743 cubic meters) of borrow material would 

be dredged from up to 1,070 acres (433 ha) of Lake Borgne water bottoms for placement into 

wetland creation and nourishment sites. 

ALTERNATIVE 3: Indirect impact of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 3 would create, nourish and 

protect a net total of 2,284 acres (925 ha) of emergent wetland-type soils over the 50-year 

period of analysis. A total of 11,400,000 cy (8,704,492 cubic meters) of borrow material would 

be dredged from 1,850 acres (750 ha) of Lake Borgne water bottoms for placement into wetland 

creation and nourishment sites. 

4.1.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic interaction of the 

effects of this alternative plan with the additive combination of impacts and benefits for overall 

net acres created, nourished, and protected by other Federal, state, local, and private restoration 

efforts including: CWPPRA 33,690 acres (13,649 ha); State 2,543 acres (1,030 ha); Mitigation 

Civil Works 4,990 acres (2,022 ha); Mitigation Regulatory Permits 6,411 acres (2,597 ha); 

Vegetation 535 acres (217 ha); Section 204/1135, Beneficial Use 226 acres (92 ha); WRDA 

16,000 acres (6,482 ha), for a total of 64,410 acres (26,095 ha) (Table 4.2). 

Alternative 10 (SP) would work synergistically with other projects within the general area to 

benefit soil resources and restore and protect the Lake Borgne and MRGO critical land bridge to 

a greater extent than would be expected from the individual efforts: 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 22

y CWPPRA PO-30 Lake Borgne Shoreline Protection project. 

y The MRGO 2006 Lake Borgne Shoreline Protection, (Doulluts Canal to Jahncke’s 

Ditch), St. Bernard Parish, LA (06-C-0210) project. 

y The MRGO 2007 North Bank Foreshore Dike Construction and Repairs, Mile 44.4 to 

Mile 39.9 (Non-Continuous), St. Bernard Parish, LA (07-C-0089) project. 

y Passage of the WRDA 2007 authorizes construction of several projects that would 

provide positive cumulative impacts in reducing the loss of soil resources throughout the 

project area, including: 

y MRGO rock closure structure at Mile 36 that would help to restore and protect the 

ecosystem. 

y The LCA Plan near-term restoration features including the MRGO environmental 

restoration feature and the Violet Diversion feature. 

Alternative 10 (SP) shoreline protection features would tie into or complement the shoreline 

protection features of the CWPPRA PO-30 project, where appropriate. Together, these features 

would synergistically interact to benefit soil resources and restore and protect the Lake Borgne 

and MRGO critical land bridge to a greater extent than would be expected from the individual 

efforts. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.2 COASTAL VEGETATION RESOURCES 

4.2.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on coastal vegetation resources. Indirect impacts of 

not implementing wetland creation/nourishment and shoreline protection features would result 

in the persistence of existing conditions including continued bankline erosion and sloughing of 

the shoreline, and continued fragmentation and conversion of existing brackish and saline marsh 

to shallow open water habitats. Both man-made and natural processes would contribute to the 

continued loss of vegetated habitats, including: continued shoreline erosion and subsidence, 

increased saltwater intrusion, increased water velocities, and increased herbivory. 

With no action, 9,850 acres (3,991 ha) of emergent wetlands in the project area are predicted to 

be lost over the next 50 years. About 6,255 acres (2,534 ha) of brackish marsh and 3,595 acres 

(1,454 ha) of saline marsh are projected to be lost. Overall, the majority of direct land loss is 

expected to occur from interior wetlands. However, substantial wetland losses are also 

predicted to occur due to shoreline erosion. If the Lake Borgne and MRGO land bridge is 

breached, existing vegetated wetlands along this critical land bridge would be converted to open 

water; and those wetlands remaining in the area would be exposed to greater hydrologic forcing 

factors (tidal flow and wave action). 

Other indirect impacts include the loss of important and essential vegetated habitats used by fish 

and wildlife for shelter, nesting, feeding, roosting, cover, nursery, and other life requirements; 

loss of productivity; loss of transitional habitat between estuarine and marine environments; 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 23

increased inter- and intra-specific competition between resident and migratory fish and wildlife 

species for decreasing wetland resources. 

Cumulative impacts would be the synergistic effect of implementing the No-Action Alternative 

with the additive combination of coast wide wetland loss and degradation, as well as the 

benefits and impacts of other state and Federal projects in the vicinity, as detailed in 

Section 4.1.1. The Water Resources Development Act (WRDA) of 2007 authorized design and 

implementation of a freshwater diversion at or near Violet, Louisiana, for the purposes of 

reducing salinity in the western Mississippi Sound, enhancing oyster production, and promoting 

the sustainability of coastal wetlands. Preliminary modeling (personal communication, Ms. 

Tomma Barnes, USACE Project Manager for the Violet Diversion, August 12, 2008) indicates 

it would require up to 15,000 cfs (425 m3/sec) to accomplish these goals. Coupled with the 

closure structure on the MRGO channel at the Bayou La Loutre ridge, the diversion at or near 

Violet, Louisiana would freshen the surrounding waters, albeit to an unknown extent. This 

could result in a conversion of some saline marshes to brackish marshes in the southern reaches 

of the project area. However, such wetland conversion would probably have little effect on the 

species composition of the wetlands in the project area other than a slight shift towards less salttolerant species. The introduction of nutrients would likely increase the productivity of the 

nearby marshes. 

4.2.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Direct impacts to coastal vegetation resources would primarily 

result from construction activities related to placement of fill material for wetland creation and 

nourishment. Shoreline protection features would be constructed just offshore, so as to avoid 

potential adverse impacts to existing vegetation resources near the shoreline and would 

therefore have no direct impact on existing vegetation. Alternative 10 (SP) includes three 

shoreline protection features located along the Lake Borgne shoreline that would protect a total 

of 522 acres (211 ha) of adjacent wetlands from degradation and wave erosion (see Tables 2.6 

and 4.3). Approximately 2,650 acres (1,074 ha) of shallow open water and fragmented 

brackish marsh, and approximately 695 acres (282 ha) of shallow open water and fragmented 

saline marsh would be directly impacted by placement of approximately 9,700,000 cy 

(7,406,454 cubic meters) of borrow material for wetland creation and nourishment (Tables 2.6 

and 4.3). However, compared to the No-Action Alternative, Alternative 10 (SP) would create, 

nourish and protect a net total of 2,162 acres (876 ha) with a value of 1,189 Average Annual 

Habitat Units (AAHUs, described in Section 2.4.4). 

In the Golden Triangle area, borrow material would be used to convert approximately 

1,250 acres (506 ha) of fragmented brackish marsh and shallow open water areas to brackish 

marsh, as well as nourish an estimated 1,400 acres (567 ha) of fragmented brackish marsh. In 

the area west of Shell Beach, borrow material would be used to convert approximately 

425 acres (172 ha) of shallow open water areas to saline marsh, as well as nourish an estimated 

270 acres (109 ha) of fragmented saline marsh. Dredged material would be placed directly into 

shallow open water areas to a slurry elevation of +3.2 ft (ft) (1.0 m) NAVD88 and the effluent 

allowed to flow over the adjacent fragmented wetlands for marsh nourishment. Following 

dewatering and consolidation, final marsh elevations would be between +0.5 ft and +1.5 ft (+0.2 

to +0.5 m) NAVD88. Proposed wetland creation and nourishment features would require the 

construction of earthen retention dikes. Material used for construction of retention dikes would 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 24

be borrowed from within the wetland creation/nourishment sites to minimize adverse impacts. 

Existing earthen ridges located along the south shore of Lake Borgne would also be used, to the 

maximum extent practicable, for dredged material slurry retention. 

Borrow material taken from Lake Borgne would be placed directly into open water and on top 

of existing fragmented marsh, which would cover any existing fragmented emergent vegetation. 

Existing fragmented emergent vegetation would generally be covered with less than one foot 

(0.3 m) of borrow sediments. Based on previous experience in marsh creation, it is anticipated 

that vegetation would rapidly re-colonize the area within nine to twelve months. Furthermore, 

existing fragmented emergent vegetation would serve as a source for re-vegetation. Wetland 

nourishment would introduce sediments into this sediment-starved system thereby providing 

better quality substrate for existing vegetation and for vegetative reestablishment. 

Compared to the No-Action Alternative, Alternative 10 (SP) would delay the conversion of 

brackish and saline marsh to open water habitats, create EFH, restore the Golden Triangle 

wetlands, help to maintain the critical land bridge between Lake Borgne and MRGO areas, 

protect interior marshes, and decrease shoreline erosion along Lake Borgne caused by tidal 

surge and wind-driven waves. 

Table 4.3 Total Acres and AAHU of Emergent Wetlands Created and Nourished Under 

the Three Alternative Plans 

Wetland 

creation 

feature 

Brackish 

marsh 

created 

(acres) 

Saline 

marsh 

created

(acres) 

Brackish 

marsh 

nourished

(acres) 

Saline 

marsh 

nourished

(acres) 

Total acres 

created 

and 

nourished 

Net acres AAHUs 

Golden 

Triangle 1,250 0 1,400 0 2,650 1,495 856 Plan 10 

(SP) Shell 

Beach 0 425 0 270 695 397 256 

Plan 2 Golden 

Triangle 1,500 0 1,350 0 2,850 1,685 1,094 

Golden 

Triangle 1,400 0 1,350 0 2,750 1,608 1,038 

Plan 3 

Shell 

Beach 0 500 0 420 920 479 329 

ALTERNATIVE 2: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 2 would create and nourish a 

total of 2,850 acres (1,155 ha) of brackish marsh at the Golden Triangle. Borrow material 

would be used to convert approximately 1,500 acres (608 ha) of fragmented emergent wetlands 

and shallow open water areas to brackish marsh, as well as nourish an estimated 1,350 acres 

(467 ha) of fragmented brackish marsh. Alternative 2 would create and nourish approximately 

200 more acres (81 ha) of brackish marsh than the SP. However, Alternative 2 would not 

restore the 695 acres (282 ha) of saline marshes in the critical land bridge that Alternative 10 

would. 

Lake Borgne shoreline protection features located near Bayou Bienvenue, Bayou Dupre, and 

West of Shell Beach would have the same direct impacts as the SP. However, Alternative 2 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 25

would construct shoreline protection for the Golden Triangle area between Bayou Bienvenue 

and Bayou Thomas, a feature not present in the SP, that would protect 115 net acres (47 ha). 

Alternative 2 would also use Articulated Concrete Mattresses (ACM) as the protection feature 

along the southern shoreline of the MRGO channel, which would protect 194 net acres (79 ha). 

The placement of ACM along the MRGO shoreline would cover and destroy about 16 acres 

(6.5 ha) of existing vegetation. However, placement of ACM would halt the currently eroding 

shorelines such that the existing emergent wetland would be protected and future erosion 

minimized. The net benefits of Alternative 2 would be 2,110 acres (855 ha) with a value of 

1,217 AAHUs compared to the No-Action Alternative. 

ALTERNATIVE 3: Direct impacts of Alternative 3 would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 3 would create and nourish 

approximately 100 acres (41 ha) more brackish marsh and 225 acres (91 ha) more saline marsh 

than Alternative 10 (SP). The proposed action at Golden Triangle would create 2,750 acres 

(1,114 ha) of brackish marsh. Borrow material would be used to convert approximately 

1,400 acres (567 ha) of shallow open water areas to brackish marsh, as well as nourish an 

estimated 1,350 acres (547 ha) of fragmented brackish marsh. At Shell Beach, an estimated 

500 acres (203 ha) of shallow open water areas would be converted to saline marsh and 

420 acres (170 ha) of existing fragmented saline marsh would be nourished. 

Shoreline protection in Lake Borgne near Bayou Bienvenue and West of Shell Beach would 

have the same direct impacts as the SP. The net benefit of implementing Alternative 3 would be 

2,284 acres (925 ha) of wetlands with a value of 1,423 AAHUs compared to the No-Action 

Alternative. 

4.2.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Indirect impacts of implementing Alternative 10 (SP) would 

include: increased acreage of important and essential 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 vegetation 

resources. Alternative 10 (SP) would also aid in the preservation of the critical land bridge 

between Lake Borgne and the MRGO channel, which would help reduce, to some undetermined 

extent, storm surge and storm wave heights from Lake Borgne and the MRGO as well as 

provide some protection against wind and storm driven waves. Alternative 10 (SP) would also 

provide protection to interior marshes and decrease interior land loss in the wetland creation 

sites by approximately 50 percent. 

Alternative 10 (SP) would enhance brackish and saline marsh habitat quality; reduce conversion 

to open water habitat; and provide EFH, especially nursery habitat, for several species, 

including brown and white shrimp, and blue crab. Newly created brackish and saline marsh 

platforms would provide substrate for the re-establishment of a variety of wetland species that 

would aid in sediment trapping for future macrophytic colonization. Salinity regimes would not 

appreciably change, but increased contributions to vegetative productivity would come from the 

expansion of new vegetative habitat on newly created and nourished areas. The flooding 

frequency and duration of inundation would be reduced, such that the stress these events impose 

on emergent vegetation would decrease. Important stopover habitats used by migrating 

neotropical birds would be sustained for future use. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 26

Erosion along reaches with shoreline protection features would be expected to cease. However, 

those wetlands located behind shoreline protection features that are not part of the wetland 

creation/nourishment features would be expected to continue to subside, and would experience 

current background interior loss rates (1.02%/year and 0.65%/year, respectively). 

Compared to the No-Action Alternative, Alternative 10 (SP) would delay the conversion of 

brackish and saline marsh to open water habitats, create EFH, restore the Golden Triangle and 

critical land bridge between Lake Borgne and MRGO areas, protect interior marshes, decrease 

shoreline erosion in Lake Borgne caused by tidal surge and wind driven waves, as well as 

decrease bankline erosion in the MRGO channel. Based upon recent sensitivity studies 

conduced by the Engineer Research and Development Center (ERDC) in support of the South 

Louisiana Comprehensive Coastal Protection and Restoration (LACPR) evaluation of 

comprehensive hurricane protection analysis and designs, the loss of wetland areas does 

increase storm surge and wave potential at the hurricane protection system (personal 

communication, Mr. Ty Wamsley, ERDC, April 24, 2007). However, because the acreage of 

wetlands lost, levee heights and alignments, shoreward depths and storm characteristics all 

affect the height of storm surge, it is difficult to determine at this stage of scientific knowledge 

the effect of wetland loss in the area around Lake Borgne on storm surge (personal 

communication, Mr. Van Stutts and Ms. Janice Hote, LACPR Hydrology Team, December 19, 

2007). Newly created and nourished emergent wetlands would have a net effect of lower storm 

surge and a lower maximum storm wave height for smaller storm conditions compared to the 

future conditions with the No-Action Alternative with extensive emergent wetland loss. The 

absolute extent of this effect is not yet quantifiable. 

ALTERNATIVE 2: Indirect impacts of Alternative 2 would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 2 would not create or nourish 

695 acres (282 ha) of saline marshes in the critical land bridge between Lake Borgne and the 

MRGO; therefore, continued conversion of saline marsh to open water in this area would 

continue. 

ALTERNATIVE 3: Indirect impacts of implementing Alternative 3 would be similar to those 

described for Alternative 10 (SP), with the following exceptions. This alternative would create 

and nourish 100 acres (41 ha) more brackish marsh, and 225 acres (91 ha) more saline marsh 

than the SP. 

4.2.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts of implementing Alternative 10 (SP) would be 

the synergistic effect with the additive combination of impacts and benefits for overall net acres 

created, nourished, and protected by other Federal, state, local, and private restoration efforts, as 

summarized in Sections 4.1.1 and 4.1.4. The WRDA 2007 authorized diversion at or near 

Violet, Louisiana (personal communication, Ms. Tomma Barnes, USACE Project Manager for 

the Violet Diversion, August 12, 2008) would require up to 15,000 cfs (425 m3

/sec) to 

accomplish these goals. Coupled with the closure structure on the MRGO channel at the Bayou 

La Loutre ridge, this feature would freshen the surrounding waters, albeit to an unknown extent. 

This could result in a conversion of some saline marshes to brackish marshes in the project area. 

In addition, the introduction of nutrient-rich Mississippi River waters would likely increase the 

productivity of wetlands throughout the project area. Alternative 10 (SP) would protect, create 

and nourish a net total of 2,162 acres (876 ha) that would synergistically interact with the other 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 27

Federal, state and local projects to provide more complete protection for the land bridge and its 

associated wetland habitats. 

ALTERNATIVE 2: Cumulative impacts of Alternative 2 would be similar to those described 

for Alternative 10 (SP), except Alternative 2 would protect, create and nourish a net total of 

2,264 acres (917 ha). 

ALTERNATIVE 3: Cumulative impacts of Alternative 3 would be similar to those described 

for Alternative 10 (SP), except Alternative 3 would protect, create and nourish a net total of 

2,284 acres (917 ha). 

4.3 WILDLIFE RESOURCES 

4.3.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on wildlife resources. Indirect impacts of 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions including the continued conversion of existing wetlands 

used as foraging, nesting, and over-wintering habitat to open water habitats; and the continued 

bankline erosion and sloughing of the shoreline. 

Indirect impacts would include the decline in habitat quality as wetlands continue to deteriorate 

and fragment, specifically in the critical land bridge between Lake Borgne and the MRGO 

channel. As interior wetlands convert to open water, there would be an expected loss of species 

richness. The effect of such wetland habitat degradation and loss would likely result in a 

localized decrease in wildlife use of the area. 

The Coast 2050 Plan shows the status, functions of interest, trends, and projections through 

2050 for avifauna, furbearers, game mammals, and reptiles across the state by mapping units 

(LCWCRTF & WCRA 1999). The South Lake Borgne mapping unit encompasses the land 

bridge between the MRGO and Lake Borgne (project area), and the Lake Borgne mapping unit 

encompasses the open waters of Lake Borgne northward to the Rigolets (see Table 3.2). Bald 

eagle, geese, woodland resident or migrant birds, and squirrels are not historically present in 

these mapping units. Avian resources in the project area are expected to either remain steady or 

decline, with the exception of brown pelican, which are expected to increase their use of open 

water habitats in both mapping units. All other wildlife resources are expected to decline with 

the No-Action Alternative. 

Cumulative impacts would be the synergistic effect of implementing the No-Action Alternative 

with the additive combination of coast wide wildlife habitat losses and degradation, as well as 

the benefits and impacts of other state and Federal projects in the vicinity, as detailed in 

Section 4.1.1. 

4.3.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): During implementation of Alternative 10 (SP), construction 

activities may disrupt or displace wildlife resources. However, any such impacts would be 

localized and temporary, and most wildlife species would move to an area with more favorable 

conditions and return after construction is completed. No permanent displacement would be 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 28

expected from the construction of the foreshore protection features. Any loss of habitat would 

be offset by the creation and nourishment of 2,650 acres (1,074 ha) of brackish marsh at Golden 

Triangle and 695 acres (282 ha) at Shell Beach. Furthermore, there would be 49,280 ft 

(15,020 m) of protected shoreline that would enhance and protect interior marshes and marsh 

edge. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.3.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Indirect impacts to wildlife resources resulting from wetland 

creation/nourishment and shoreline protection features would include the creation, restoration, 

and protection of wetland habitats utilized by those species for nesting, rearing of young, 

resting, and foraging activities. An increase in wetland acreage would provide increased 

nesting, brood-rearing, and foraging habitat for resident and migrant avian species. Wetland 

creation/nourishment and shoreline protection would also help to increase and preserve 

important stopover habitat for neotropical migrants and wintering habitat for waterfowl. 

The Coast 2050 Plan, Appendix C (LCWCRTF & WCRA 1999) lists brackish and saline marsh 

as potential nesting habitat for “other marsh and open water residents,” which include anhinga, 

least bittern, and seaside sparrow. In the project area, these marshes may also provide nesting 

habitat for other perching birds, such as redwing blackbird. 

The project would create, nourish and protect estuarine areas frequented by wintering waterfowl 

and may create a few interior ponds and swales attractive to breeding waterfowl and rails, 

particularly mottled ducks and clapper rails. The quality of essential fish habitat would be 

improved, which would increase the abundance of prey items for wildlife such as wading birds. 

For instance, the National Marine Fisheries Service (NMFS), in a scoping letter dated 

December 20, 2006, noted that the wetlands and water bodies in this area serve as nursery and 

foraging habitat for striped mullet, Atlantic croaker, Gulf menhaden, spotted and sand seatrout, 

southern flounder, black drum, and blue crab (see Appendix C). 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.3.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts, as summarized in 

Section 4.1.4. Alternative 10 (SP) would work synergistically with the CWPPRA projects to 

provide more complete protection for the land bridge and its associated wetland habitats. 

Approximately 2,162 acres (876 ha) more of important stopover habitat (brackish and saline 

marsh) would be available for migratory neotropical songbirds and waterfowl in 50 years 

compared to the No-Action Alternative. Although unlikely to impact their populations on a 

continental scale, game animals, furbearers, reptiles, amphibians, and invasive species 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 29

(especially nutria) that utilize the project area would also benefit from the cumulative effects of 

creating, nourishing and protecting these wetlands. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.4 FISHERY RESOURCES 

4.4.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on fishery resources. Indirect impacts of not 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions including the continued conversion of existing fragmented 

and deteriorating emergent wetlands and intertidal habitats to shallow open water; continued 

loss of fragmented and deteriorating transitional wetland habitats between estuarine and marine 

environments used by fish for shelter, nesting, feeding, cover, nursery, and other life 

requirements; increased inter- and intra-specific competition between resident and migratory 

fish species; and continued bankline erosion and sloughing of the shoreline. 

Over time, indirect impacts of the No-Action Alternative would result in a substantial decrease 

in the quality of EFH in the project area, including nursery habitat and marsh edge in the project 

area, and reduce the area’s ability to support Federally-managed species. The abundances of 

aquatic organisms would decrease, indirectly impacting species that are linked in the food web 

to directly affected species. The reduction in emergent wetlands would also result in shifts in 

predator/prey relationships, a decline in fishery productivity, and reduced recreational fishing 

opportunities. 

Table 3.4 shows current and projected population trends for fish guilds in the project area 

(LCWCRTF & WCRA, 1999). Trends toward a predominantly marine fish population and 

increased salinity in the project area were identified by Fontenot and Rogillo (1970) during the 

early 1960s. Since that time, little has taken place in the area to reduce or prevent increasing 

salinities in the marshes, wetlands and waterways in the project area. Therefore, impacts from 

increased salinities on fish populations in the project area have most likely already occurred. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative with the 

additive combination of coast wide fishery habitat losses and degradation, as well as the 

benefits and impacts of other state and Federal projects in the vicinity, as detailed in Section 

4.1.1. Predictions from the Coast 2050, Habitat Switching and Land-Building models were 

used to assess changes in fisheries habitat. The models predict changes in marsh-type and 

marsh loss and gain, which, combined with other factors, were used to predict habitat suitability 

and fisheries productivity for Louisiana coastal areas. Sharp declines are predicted in fisheries 

productivity under the No-Action Alternative (Minello et al. 1994; Rozas and Reed et al 1993; 

in LCA 2004). The LCA Study (USACE, 2004) estimated a net loss of 328,000 acres 

(132,794 ha) of coastal wetland habitats may occur by 2050. This is almost ten percent of 

Louisiana’s remaining coastal wetlands, which is utilized by various fish species for shelter, 

foraging, cover, nursery, and other life requirements. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 30

4.4.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Direct impacts to fisheries resources would generally be associated 

with construction activities including placement of shoreline protection and dredging and 

placement of borrow material. Sessile or slow moving fisheries resources would likely suffer 

some mortality or injury during placement of shoreline protection and/or during dredging and 

placement of borrow material. Construction activities would temporarily increase turbidity, 

temperatures and biological oxygen demand (BOD); and decrease dissolved oxygen. These 

temporary conditions would likely displace more mobile fisheries species from the construction 

area. Following construction, displaced fisheries species would likely return to the project area. 

The excavation of floatation access for construction of shoreline protection and wetland creation 

features in Lake Borgne would impact a total of 118.3 acres (47.9 ha) of nearshore water 

bottoms in Lake Borgne. Material dredged from these access channels would be used 

beneficially to create emergent wetland habitat between the rock dike and the shoreline to the 

maximum extent practicable. The remaining material would be backfilled or left for waves to 

wash back into the channel naturally. Increases in turbidity and temperature and a decrease in 

DO associated with these actions would be temporary and localized. An additional 39.5 acres 

(16.0 ha) of nearshore shallow water habitat would be covered with rock for dike construction, 

and material from the floatation channels is anticipated to cover up to 82.7 acres (33.5 ha) of 

shallow water bottom between the rock dike and the existing shoreline. This would be placed to 

a final elevation of between +0.5 ft to +1.5 ft (+0.2 to +0.5 m) NAVD88, which would be 

conducive to establishing emergent wetlands. 

All shoreline protection features would incorporate openings approximately every 1,000 ft 

(305 m), as needed, and allow historical channels to remain open for all organisms’ ingress and 

egress following protocols set by USFWS and NMFS. These access features would facilitate 

movement of various fisheries species to wetlands protected within the proposed shoreline 

protection reaches, and minimize the impact of shoreline protection features on aquatic 

organism access to the Lake Borgne shoreline. 

ALTERNATIVE 2: Direct impacts of Alternative 2 would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 2 would create and nourish 

200 acres (81 ha) more emergent brackish marsh than the SP. This alternative does not include 

an emergent saline marsh creation and nourishment feature. However, Alternative 2 would 

include an additional shoreline protection feature (ACM) on the south bank of the MRGO. A 

total of 49.8 acres (20.2 ha) of nearshore shallow water and emergent wetland habitats would be 

covered with the ACM and a total of 74.0 acres (30.0 ha) of these habitats would be covered by 

rock for shoreline protection. Material dredged for floatation access would be beneficially 

placed over a total of 95.2 acres (38.6 ha) of shallow water bottoms between the rock dike and 

the existing shoreline. Material dredged for floatation access for placement of ACM would be 

beneficially placed over 62.7 acres (25.4 ha) of shallow water bottoms. 

ALTERNATIVE 3: Direct impacts of Alternative 3 would be similar to those described for 

Alternative 10 (SP), with the following exceptions. This alternative would create and nourish 

100 acres (41 ha) more emergent brackish and 225 acres (91 ha) more emergent saline marsh 

than the SP. A total of 47.2 acres (19.1 ha) of nearshore shallow water habitat would be 

covered with rock for dike construction. Material dredged for floatation access would be 

beneficially placed over 45.5 acres (18.4 ha) of shallow water bottoms between the rock dike 

and the existing shoreline. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 31

4.4.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Construction of Alternative 10 (SP) would provide a net benefit of 

2,212 acres (896 ha) of wetlands and 1,202 AAHUs compared to the No-Action Alternative, 

which would prevent the further loss of brackish and saline marshes and aid in maintaining 

valuable EFH. These wetlands would provide habitats for foraging, breeding, spawning, and 

cover for a variety of larval, juvenile and adult fishes. Access features in the shoreline 

protection features would facilitate ingress and egress of various fisheries species to wetlands 

protected within the project area, and retention dikes in the wetland creation sites will degrade 

to allow access to newly created and nourished wetlands as well. 

A localized increase in biodiversity and some fish populations would be expected by the net 

increase of emergent wetlands constructed by Alternative 10 (SP) compared to the No-Action 

Alternative. More nutrients and detritus would be added to the food web, thereby increasing 

fish productivity and providing a benefit to local fisheries. Recreational activities, such as 

fishing, would also benefit from the increase in fish populations. 

The long-term sustainability of local fisheries would be more likely with implementation of 

Alternative 10 (SP) than in the No-Action Alternative. Increased productivity, as a result of 

wetland creation and protection features in the critical land bridge area between Lake Borgne 

and MRGO, would provide indirect benefits to fisheries through an increase in the energy 

inputs into the food web of the ecosystem in this area. 

Louisiana has an extensive and productive oyster lease program, compared to other states, 

providing more than 50% of the Nation’s oyster harvest (USACE, 2004). Implementation of 

Alternative 10 (SP) would be expected to indirectly benefit local oyster populations. Protection, 

creation and nourishment of transitional habitats would provide higher quality habitats that 

would better sustain and maintain local oyster populations as compared to the No-Action 

Alternative. 

ALTERNATIVE 2: Indirect impacts of Alternative 2 would be similar to those described for 

Alternative 10 (SP), with the following exception. Approximately 200 acres (81 ha) more 

brackish marsh would be created and nourished with this alternative than with the SP. These 

emergent brackish marshes would provide a higher quality habitat for foraging, breeding, 

spawning, and cover for a variety of adult and juvenile fisheries, as compared to the No-Action 

Alternative. However, under Alternative 2, no additional saline marsh would be created or 

nourished. 

ALTERNATIVE 3: Indirect impacts of Alternative 3 would be similar to those described for 

Alternative 10 (SP), with the following exception. Approximately 100 acres (41 ha) more 

emergent brackish marsh would be created and nourished and 225 acres (91 ha) more saline 

marsh would be created and nourished. 

4.4.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4. Alternative 10 (SP) would synergistically interact with the CWPPRA (PO 30) 

restoration project and other Federal, state, local, and private restoration efforts (see 

Sections 4.1.1 and 4.1.4) thereby providing more complete protection for the land bridge and its 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 32

associated fishery habitat. Alternative 10 (SP), together with these other restoration projects in 

the Lake Borgne area, would protect, create and nourish essential transitional wetland habitats 

thereby increasing the base of the existing food web and providing a positive benefit to local 

area fisheries. 

Louisiana’s oyster lease program provides more than 50 percent of the Nation’s oysters. Hence, 

any project that impacts oyster resources in Louisiana would impact nationwide oyster harvest, 

in addition to impacting the contribution of this industry to the local, state, and national 

economy (USACE 2004). However, oyster populations are anticipated to benefit from 

implementing not only Alternative 10 (SP), but other larger-scale coastal restoration efforts. 

ALTERNATIVE 2: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

4.5 PLANKTON RESOURCES 

4.5.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on plankton resources. Indirect impacts of not 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions including the continued degradation and eventual loss of 

wetlands. This loss of wetlands would eventually result in a decrease of available nutrients and 

detritus, which could lead to the conversion of primarily estuarine-dependent plankton species 

assemblages to more marine and open water plankton species assemblages. Cumulative 

impacts would be the synergistic effect of the No-Action Alternative on plankton resources with 

the additive combination of similar wetland degradation and wetland loss impacts to plankton 

resources throughout coastal Louisiana, as well as the benefits and impacts of other state and 

Federal projects in the vicinity, as detailed in Section 4.1.1. 

4.5.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): There would be localized and short-term adverse impacts, 

including mortality of some plankton populations, due to construction activities associated with 

placement of shoreline protection features, dredging and placement of borrow. During 

construction, there would be a localized and short-term decrease in available dissolved oxygen; 

and an increase in turbidity, temperature, and biological oxygen demand (BOD). Following 

construction and dredging operations, the area would return to ambient conditions and be recolonized by plankton populations. Existing shallow open water and fragmented wetland 

habitats would be converted to 2,650 acres (1,074 ha) of brackish and 695 acres (282 ha) of 

saline wetland-type soils. Protection, creation and nourishment of transitional brackish and 

saline wetlands would enhance and increase, to some undetermined level, aquatic productivity 

and nutrient transformation functions.

ALTERNATIVE 2: Direct impacts of Alternative 2 would be similar to those described for 

Alternative 10 (SP), with the following exceptions. There would be fewer impacts associated 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 33

with dredging activities compared to Alternative 10 (SP) as only one borrow site (see 

Figure 2.1) would be used for wetland creation and nourishment under Alternative 2. 

ALTERNATIVE 3: Direct impacts of Alternative 3 would be similar to those described for 

Alternative 10 (SP). 

4.5.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): An increase in the export of dissolved organic compounds and 

detritus from the created and nourished wetland habitats would benefit local plankton 

populations by increasing the planktonic food web. Some local plankton populations would be 

displaced and there would be a long-term loss of some shallow open water habitats in the 

project area due to construction project features. However, there is an abundance of shallow 

open water habitat throughout the project area for use by planktonic resources. 

ALTERNATIVE 2: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP), except that increases in energy inputs to the planktonic food web would be 

much lower in the eastern lobe of Lake Borgne, because no wetlands would be created in that 

portion of the project area. 

ALTERNATIVE 3: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.5.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts to plankton resources would primarily be 

associated with the incremental impacts of similar wetland creation, nourishment, and shoreline 

protection features. Cumulative impacts would be the synergistic effect with the additive 

combination of impacts and benefits for overall net acres created, nourished, and protected by 

other Federal, state, local, and private restoration efforts as summarized in Section 4.1.4. 

Alternative 10 (SP) would synergistically interact with these other restoration projects to 

provide more complete protection for the land bridge and its associated transitional wetlands, 

which provide important and essential energy inputs to the planktonic food web. 

ALTERNATIVE 2: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

4.6 WATER BOTTOMS AND BENTHIC RESOURCES 

4.6.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on water bottoms or benthic resources. Indirect 

impacts of not implementing wetland creation/nourishment and shoreline protection features 

would result in the persistence of existing conditions. Existing emergent wetlands would be 

converted to water bottoms and would no longer be available for use by benthic species 

assemblages that typically utilize emergent wetland habitats. Other indirect impacts include a 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 34

decrease of available nutrients and detritus and conversion of primarily estuarine-dependent 

benthic species assemblages to more marine and open water benthic species assemblages. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative with the 

additive combination of similar emergent wetland degradation and conversion to water bottoms 

and resultant impacts to benthic resources throughout coastal Louisiana, as well as the benefits 

and impacts of other state and Federal projects in the vicinity, as detailed in Section 4.1.1. 

4.6.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): This alternative would borrow 9,700,000 cy (7,406,454 cubic 

meters) of material from Lake Borgne excavating a total of 1,850 acres (750 ha) of water 

bottoms. Placement of this material for emergent wetland creation and nourishment would 

cover approximately 3,345 acres (1,355 ha) of shallow open water and existing fragmented 

marsh. Placement of rock for shoreline protection features would cover approximately 

39.5 acres (16.0 ha). Dredging floatation access for construction activities would impact 

118.3 acres (47.9 ha) of Lake Borgne water bottoms. Material dredged for floatation access 

would be placed over approximately 82.7 acres (33.5 ha) of shallow water bottoms. These 

actions would directly impact and destroy any slow-moving or sessile benthic organisms found 

within the proposed borrow areas, floatation access channels, wetland creation, and shoreline 

protection footprints. More mobile benthic species utilizing the area would likely be displaced 

to more suitable habitats. 

The removal of borrow material would impact less than 1.1 percent of the total Lake Borgne 

water bottoms. 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. 

ALTERNTIVE 2: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 2 would utilize only one borrow 

site (see Figure 2.1) and would require 200,000 cy (152,710 cubic meters) less borrow material 

and would impact 780 acres (316 ha) fewer Lake Borgne water bottoms than Alternative 

Plan 10 (SP). A total of 186.2 acres (75.4 ha) of Lake Borgne and MRGO water bottom soils 

would be dredged for floatation access, which would be used for wetland creation, to the 

maximum extent practicable, and would eventually convert to emergent wetland-type soils. 

ALTERNATIVE 3: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.6.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Indirect impacts to benthic resources would be related primarily to 

disturbance of water bottoms during placement of shoreline protection features and also during 

dredging and placement of borrow material. Short-term disturbance to benthic species would 

likely occur from increased turbidity, temperature and biological oxygen demand (BOD); and 

decreased dissolved oxygen due to hydraulic dredging, marsh creation, and placement of 

shoreline protection activities. Some smothering of benthic organisms may also occur from the 

resettlement of the dredge plume, but these impacts would be minimized through the use of silt 

curtains or other construction measures to minimize dredging impacts. Indirect impacts would 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 35

be generally be localized and temporary. Waters would return to ambient conditions following 

construction. 

Dredging activities would cause temporary habitat degradation to existing water bottoms used 

by benthos for various life requirements. Any such impacts would initially cause increased 

inter- and intra-specific competition between various benthic species for nearby available 

habitat resources. There would also be a shift in species composition to those benthic species 

more tolerant of disturbance. However, any such impacts would be temporary as benthos would 

likely quickly re-colonize areas disturbed by dredging activities. Actions taken to reduce 

potential impacts during construction could include the use of silt curtains and retention dikes to 

minimize the effects of runoff, overland flow, and sediment movement and erosion into 

adjacent waterways and marshes, except where nourishment activities are desired. These 

measures could also help to restrict the extent of increases in turbidity and suspended 

particulates to the immediate construction area. 

Transitional wetland habitats protected, created and nourished by Alternative 10 (SP) 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. This 

would eventually increase local epifauna which, in turn, would help reduce turbidity, regenerate 

ammonia and phosphorous, and serve as important sources of food for birds, nekton, and people 

(Day et al., 1989). 

ALTERNATIVE 2: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exceptions. Alternative 2 would utilize only one borrow 

site in Lake Borgne (Figure 2.1). This would require 200,000 fewer cubic yards 

(152,710 fewer cubic meters) of borrow material and would impact 780 fewer acres (316 fewer 

hectares) than Alternative Plan 10 (SP). Hydraulic dredging would not take place in the eastern 

lobe of Lake Borgne, and no additional wetlands would be created in the Shell Beach area. 

ALTERNATIVE 3: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.6.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4. Alternative 10 (SP) would work synergistically with those projects to provide 

more complete protection for the land bridge and its associated transitional wetlands, which 

provide energy inputs to the benthic food web. 

Project-induced impacts to a total of 2,091 acres (847 ha) of water bottoms and benthic 

organisms in Lake Borgne would be in addition to the impacts to benthic resources and their 

habitats caused by other wetland creation/nourishment and shoreline protection actions. 

However, any such impacts would be offset by the additional higher quality habitats created and 

protected, which would result in a net increase in benthic resources. 

ALTERNATIVE 2: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 36

ALTERNATIVE 3: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

4.7 ESSENTIAL FISH HABITAT (EFH) 

4.7.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on EFH. Indirect impacts of not implementing 

wetland creation/nourishment and shoreline protection features would result in the persistence 

of existing conditions resulting in the conversion of categories of EFH, such as inner marsh and 

marsh edge, to estuarine water column and mud, sand, or shell substrates is expected to 

continue. Over time, the No-Action Alternative would result in the conversion of 9,850 acres 

(3,991 ha) of emergent wetlands to open water. The substantial decrease in the quality of EFH 

in the project area would reduce the area’s ability to support Federally-managed species. 

Continued degradation and loss of wetlands, especially transitional habitat between estuarine 

and marine environments, would also result in the degradation and loss of important and 

essential fish habitats used for spawning, foraging, cover, nursery, and other life requirements, 

as well as result in increased inter- and intra-specific competition between resident and 

migratory fish and other aquatic species for decreasing wetland resources. The No-Action 

Alternative would substantially decrease the quality of EFH and the ability of the project area to 

support Federally-managed species. Cumulative impacts would be the synergistic effect of the 

No-Action Alternative on EFH with the additive combination of similar EFH degradation and 

losses throughout coastal Louisiana, as well as the benefits and impacts of other state and 

Federal projects in the vicinity, as detailed in Section 4.1.1. 

4.7.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Implementing Alternative 10 (SP) would convert a total 2,650 acres 

(1,074 ha) of shallow open water and fragmented brackish marsh and 695 acres (282 ha) of 

shallow open water and fragmented saline marshes to more continuous emergent wetlands. 

This increased emergent wetland acreage would provide important and essential transitional 

wetland habitats used by fish for spawning, nursery, foraging, cover, and other life 

requirements. Increased vegetation growth and productivity would also reduce inter- and intraspecific competition between resident and migratory fish species for limited coastal vegetation 

resources. 

Direct impacts of construction activities would result in the conversion of some existing shallow 

open water and fragmented wetland EFH into more continuous transitional emergent wetlands. 

Placement of the rock foreshore protection features would directly impact existing EFH (water 

bottoms) along 49,280 ft (15,020 m) of Lake Borgne shorelines (a total of 39.5 acres/16.0 ha), 

which would be unavailable for fishery species. However, this loss of EFH would be offset by 

the increases in the quality of EFH in the newly created and nourished emergent wetland sites. 

Excavation of floatation access channels would impact a total of 118.3 acres (47.9 ha) of water 

bottoms. Material dredged from access channels would be used beneficially, to the maximum 

extent practicable, to create transitional wetlands between the rock dike and the shoreline. Any 

remaining material would be backfilled or left for waves to wash back into the channel 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 37

naturally. Increases in turbidity, coupled with a slight increase in temperature and biological 

oxygen demand (BOD), and decreased dissolved oxygen associated with construction activities 

would be temporary and localized. Material dredged for floatation access would be beneficially 

used, to the maximum extent practicable, and placed between the rock dike and the existing 

shoreline to create a total of 82.7 acres (33.5 ha) of new wetlands. Placement of borrow 

material would be to an elevation conducive to establishing wetland vegetation. All remaining 

material would be stockpiled and backfilled into the channels following construction. Although 

existing EFH in these reaches would be negatively impacted, such losses of nearshore shallow 

water habitat would be offset by the creation of additional transitional wetland habitats, which 

are considered a higher-quality EFH. 

ALTERNATIVE 2: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exception. A total of 77,820 ft (23,718 m) of shoreline 

would be protected; in addition, 1,500 acres (608 ha) of brackish marsh would be created and 

1,350 acres (547 ha) nourished. 

ALTERNATIVE 3: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exception. A total of 1,900 acres (770 ha) of wetlands 

would be created and 1,770 acres (717 ha) nourished with 31,630 ft (9,640 m) of shoreline 

protected. 

4.7.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): The protection, creation and nourishment of a net total of 

2,162 acres (874 ha) of brackish and saline transitional wetlands would convert lower-quality 

categories of EFH to higher-quality categories as well as protect existing higher-quality EFH 

from converting to lower-quality categories. Shoreline protection features would not only 

prevent the erosion of interior emergent wetlands, but would also protect interior shallow ponds, 

which are essential nursery habitats for many fishery species. Shoreline protection features 

would also prevent the conversion of transitional wetland habitats, including essential inner 

marsh and marsh edge habitats, to less productive EFH categories such as open water. 

Alternative 10 (SP) would not only increase the areal extent EFH, but would also improve the 

quality of transitional wetland habitats used by fish for spawning, nursery, forage, cover, and 

other life requirements. An increase in the acreage of transitional habitat between estuarine and 

marine environments would result in decreased inter- and intra-specific competition between 

resident and migratory fish species and would sustain a larger variety and greater diversity of 

species. Some of these species serve as prey to others; therefore, predator populations may be 

indirectly enhanced as compared to the No-Action Alternative. 

ALTERNATIVE 2: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.7.4 Future With Project Conditions Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 38

Section 4.1.4. Alternative 10 (SP) would work cooperatively with those projects to provide 

more complete protection for the land bridge and associated EFH. 

ALTERNATIVE 2: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

4.8 ENDANGERED AND THREATENED SPECIES 

4.8.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on listed (endangered or threatened) species or their 

critical habitat in the project area. Indirect impacts of not implementing wetland 

creation/nourishment and shoreline protection features would result in the continued 

degradation and loss of important and essential fish and wildlife transitional wetland habitats 

used by many different fish and wildlife for shelter, nesting, feeding, roosting, cover, nursery, 

and other life requirements. The MRGO bankline and the Lake Borgne shoreline would 

continue to be eroded further reducing the land bridge between these two waterbodies. The loss 

and deterioration of transitional wetland habitats would continue to impact, to some 

undetermined degree, all listed species that utilize the project area including: Gulf sturgeon, 

green sea turtle, hawksbill sea turtle, Kemp’s Ridley sea turtle, leatherback sea turtle, 

loggerhead sea turtle, brown pelican, piping plover, and the West Indian manatee. Adverse 

cumulative impacts on listed species would be offset, to some degree, by the positive impacts of 

implementing other state and Federal projects as detailed in Section 4.1.1 and Table 4.2. 

4.8.2 Future With Project Conditions Direct Impacts 

ALTERNATIVE 10 (SP): With the exception of Gulf sturgeon critical habitat, the proposed 

action would not jeopardize the continued existence of any listed species or destroy or adversely 

modify critical habitat. Although the proposed action would involve construction activities in 

the critical habitat of the Gulf sturgeon, the proposed action is not likely to destroy or adversely 

modify Gulf sturgeon critical habitat. Hence, the CEMVN has determined the proposed action 

is Not Likely to Adversely Affect (NLAA) Gulf sturgeon critical habitat. Appendix A presents 

a Biological Assessment that describes those factors used in determining the potential impacts 

of the proposed action on the primary constituent elements for Gulf sturgeon critical habitat. 

Appendix A also presents the NMFS’ Biological Opinion (personal communication, NMFS, 

June 26, 2008) provided following initiation of formal consultation on March 13, 2008: 

It is NMFS’ biological opinion that this project is not likely to destroy or adversely 

modify Gulf sturgeon critical habitat... In summary, NMFS concludes that green, 

hawksbill, Kemp’s Ridley, leatherback, and loggerhead sea turtles; and Gulf sturgeon 

are not likely to be adversely affected by the proposed action. 

Appendices B and C contain copies of coordination letters from the USFWS and NMFS, 

respectively, for those listed species under the jurisdiction of these agencies. Any direct 

impacts to listed species or critical habitat would generally be temporary and minor, and related 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 39

primarily to dredging Lake Borgne borrow sites (1,850 acres/750 ha); dredging floatation access 

channels (118.3 acres/47.9 ha) and placement of dredged material or rock on a total of 

122.2 acres (49.5 ha) of shallow water bottoms. Construction practices (e.g., dropping the 

empty bucket of a dredge to scare off any Gulf sturgeon prior to dredging activities in floatation 

and access channels) would be employed to minimize the likelihood of impacts to individuals. 

Additionally, it is unlikely that this proposed alternative would present adverse direct impacts to 

any other listed species or their critical habitat, as detailed below. 

West Indian Manatee 

Any effects to the West Indian manatee from implementing the proposed action would be 

related to possible collision with service vessels during the construction and maintenance 

activities. All CEMNV 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. 

Controls will be implemented to ensure that the project activities are conducted first to avoid, 

and otherwise to minimize, the potential effects on manatees. The following precautions would 

be used from May to October, when manatees have the greatest potential for entering the project 

area: 

y All personnel associated with the project shall be instructed about the presence of 

manatees and the need to avoid collisions with and injury to manatees. All construction 

personnel will 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. 

y All vessels associated with the construction project shall operate at “Idle Speed/No 

Wake” at all times while in the immediate area and while in water where the draft of the 

vessel provides less than a four-foot clearance from the bottom. A sign measuring at 

least 8.5" by 11" (21.6 x 27.9 cm) explaining the requirements for “Idle Speed/No 

Wake” and the shut down of in-water operations must be posted in a location 

prominently visible to all personnel engaged in water-related activities. All vessels will 

follow routes of deep water whenever possible. 

y Siltation or turbidity barriers, if used, shall be made of material in which manatees 

cannot become entangled, shall be properly secured, and shall be regularly monitored to 

avoid manatee entanglement or entrapment. Barriers will not impede manatee 

movement. 

y All on-site project personnel are responsible for observing water-related activities for the 

presence of manatee(s). If a manatee is sighted within 100 yards (91 m) of the active 

work zone, special operating conditions shall be implemented, including: 

y No operation of moving equipment within 50 ft (15.2 m) of a manatee; 

y All vessels shall operate at no wake/idle speeds within 100 yards (91 m) of the work 

area; 

y Siltation barriers, if used, shall be re-secured and monitored. 

y Once the manatee has left the 100-yard (91-meter) buffer zone around the work area on 

its own accord, special operating conditions are no longer necessary, but careful 

observations will be resumed. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 40

y Any sighting of, collision with, or injury to a manatee shall be immediately reported to 

the USFWS (337-291-3100) and the LDWF, Natural Heritage Program (225-765-2821). 

y Temporary signs shall 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 shall 

be placed where it is visible to the vessel operator. Awareness signs that have been 

approved for these uses in Florida have had the following specifications: one sign 

measuring at least three ft by four ft (91 x 122 cm) which reads “Caution: Manatee 

Area” will be posted. A sign measuring at least 8.5" by 11" (21.6 x 27.9 cm) explaining 

the requirements for “Idle Speed/No Wake” and the shut down of in-water operations 

will be posted in a location prominently visible to all personnel engaged in water-related 

activities. All signs are to be removed upon completion of the project. 

Given the rare occurrence of manatees and the lack of manatee critical habitat within the project 

area, along with implementation of the above operational precautions, no collision fatalities are 

expected. Therefore, the proposed action will not adversely affect the West Indian manatee. 

Eastern Brown Pelican 

Brown pelicans may forage and/or roost within or in proximity to the proposed project areas; no 

nest sites are located in proximity to the proposed project areas. Potential effects to that species 

would be limited to temporary displacement during project construction. An abundance of 

suitable foraging and roosting habitat exists in proximity to the proposed project areas, and 

pelicans would not be permanently excluded from utilizing the area. Accordingly, the proposed 

action would not adversely affect the brown pelican. 

Piping Plover 

Although the piping plover may occasionally forage and/or roost on exposed flats in and around 

the proposed project areas, no such habitat would be affected by the proposed activities. Should 

any piping plovers be found in the area during construction, they would be temporarily 

displaced to nearby suitable habitat and would not be permanently excluded from the project 

areas. In addition, no piping plover designated critical habitat exists within the proposed project 

areas. Accordingly, the proposed activities would not adversely affect the piping plover. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.8.3 Future With Project Conditions Indirect Impacts 

ALTERNATIVE 10 (SP): There would be no adverse indirect impacts of implementing 

Alternative 10 (SP) to any listed species or its critical habitat. Rather, proposed wetland 

creation/nourishment and shoreline protection would provide a net increase of transitional 

coastal wetland habitats by increasing the quality of habitat; providing for improvements in 

more categories of EFH; 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 Lake Borgne water bottoms thereby 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 41

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 

creation/nourishment and shoreline protection features, which would provide a net increase of 

2,162 acres (876 ha) of transitional wetlands compared to the No-Action Alternative. However, 

there may be some temporary and localized impacts to the food supply for Gulf sturgeon as 

some of the Lake Borgne water bottoms would be dredged for borrow and floatation access. 

Any such impacts to the benthic food supply are anticipated to be minor, as only a small 

fraction of the total lake bottom would be impacted, and the benthos would recolonize borrow 

and floatation access locations rapidly following construction. The Biological Opinion 

provided by the NMFS (Appendix A) also supports this conclusion. The NMFS “does not 

expect measurable impacts to Gulf sturgeon critical habitat as a result of impacts to water 

quality, migratory pathways, sediment quality, or abundance of prey items related to this 

project” (Appendix A). 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.8.4 Future With Project Conditions Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4 and Table 4.2. Alternative 10 (SP) would synergistically interact with other 

restoration efforts thereby providing more complete protection for the land bridge separating 

Lake Borgne and the MRGO. Over the 50-year period of analysis, Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of transitional wetlands (both 

brackish and saline marsh) compared to the No-Action Alternative. Although unlikely to 

impact populations on a continental scale those listed species that utilize the project area would 

also benefit from the cumulative effects of Alternative 10 (SP) and other restoration efforts 

(e.g., CWPPRA PO 30) in the Lake Borgne area. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.9 HYDROLOGY RESOURCES 

4.9.1 Flow and Water Levels 

4.9.1.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on flow or water levels. Indirect impacts of not 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions. Based upon recent sensitivity studies conduced by the 

Engineer Research and Development Center (ERDC) in support of the South Louisiana 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 42

Comprehensive Coastal Protection and Restoration (LACPR) evaluation of comprehensive 

hurricane protection analysis and designs, the loss of wetland areas does increase storm surge 

and wave potential at the hurricane protection system (personal communication, Mr. Ty 

Wamsley, ERDC, April 24, 2007). However, because the acreage of wetlands lost, levee 

heights and alignments, shoreward depths and storm characteristics all affect the height of storm 

surge, it is difficult to determine at this stage of scientific knowledge the effect of wetland loss 

in the area around Lake Borgne on storm surge (personal communication, Mr. Van Stutts and 

Ms. Janice Hote, LACPR Hydrology Team, December 19, 2007). 

As authorized by the WRDA 2007, upon the June 5, 2008, submission of the final report to the 

Committee on Environment and Public Works of the Senate and the Committee on 

Transportation and Infrastructure of the House of Representatives, the MRGO from the Gulf of 

Mexico to Mile 60 at the southern bank of the Gulf Intracoastal Waterway is no longer 

authorized. In addition, the plan to close the MRGO includes the construction of a closure 

structure at the south ridge of Bayou La Loutre in St. Bernard Parish, Louisiana, approximately 

Mile 36 on the MRGO. Construction of the closure structure is anticipated to be completed 

before the beginning of the 2009 hurricane season. Despite deauthorization of navigation on the 

MRGO and construction of a closure structure at Bayou La Loutre, the hydrologic connections 

between Lake Borgne and the MRGO would likely increase over time as the land bridge 

continues to fragment. Lake Borgne, the GIWW, the MRGO, and Chef Menteur Pass, which 

connects Lake Borgne to Lake Pontchartrain, would continue to provide conduits for water 

movement near the project area. Flows and water levels are expected to continue similar or 

greater than existing conditions into the future. Eustatic sea level rise of 1.3 ft (0.4 m) per 

century would continue to increase water levels in the project area, and natural subsidence of 

0.50 ft (0.15 m) per century would continue to reduce the elevation of existing wetlands, such 

that the relative change in water level would be a reduction of 1.8 ft (0.55 m) per century. 

Additionally, the closure structure and sector gates on the GIWW and Bayou Bienvenue 

planned for the authorized improvements to the Greater New Orleans Hurricane and Storm 

Damage Risk Reduction System would alter flow patterns in and near the western end of the 

project area. For construction of this structure, an access channel would be dredged on the Lake 

Borgne side of the floodwall (USACE, 2008). This would connect the MRGO channel with the 

GIWW across the Golden Triangle, but would close off an existing connection. The net effect 

would likely be negligible. The gates across Bayou Bienvenue and the GIWW would remain 

open, except when a storm surge is present or anticipated. This would prevent salt-water 

intrusion into the interior marshes in storm situations, while not impeding tidal flows under 

normal circumstances. The concrete floodwall across the MRGO channel south of Bayou 

Bienvenue would stop tidal flow on the channel, but the closure structure at Bayou La Loutre 

would have a greater impact on flows in the MRGO channel. Nevertheless, the water flows 

near the sector gates are anticipated to be greater than preconstruction conditions. Additionally, 

modeling scenarios indicate that the proposed flood protection levee would raise the water 

levels by up to 0.1 ft (0.03 m), with marshes experiencing up to seven hours additional wetted 

period per day (USACE, 2008). 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on flow and 

water levels with the additive combination of similar wetland degradation and wetland loss 

impacts to flow and water levels throughout coastal Louisiana, as well as the benefits and 

impacts of other state and Federal projects in the vicinity, as detailed in Section 4.1.1 and
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 43

Table 4.2. The WRDA 2007 authorized diversion at or near Violet, Louisiana, would introduce 

up to 15,000 cfs (425 m3

/sec) of water from the Mississippi River into the project area. 

Coupled with the closure structure on the MRGO channel at the Bayou La Loutre ridge, this 

feature would freshen the surrounding waters, albeit to an unknown extent, and slightly alter the 

flow patterns in and near the project area, but would not likely affect water levels in the project 

area. 

4.9.1.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Proposed wetland creation and nourishment and shoreline 

protection features would not directly alter existing flows or water levels. Hydrologic 

connectivity between the wetland creation and nourishment sites and Lake Borgne would be 

temporarily disrupted by the construction of retention dikes. However, retention dikes would be 

designed to naturally degrade following completion of construction thereby restoring hydrologic 

connectivity with Lake Borgne. Fish access gaps incorporated into shoreline protection features 

would maintain hydrologic connectivity between the shoreline and Lake Borgne. The four 

borrow sites in Lake Borgne would be located at least 3,000 ft (914 m) from the shoreline. This 

would prevent potential borrow site-induced changes to the wave climate thereby reducing the 

risk of increased shoreline erosion rates. 

ALTERNATIVE 2: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.9.1.3 Future With Project Condition – Indirect Impacts 

ALTERNATIVE 10 (SP): Alternative 10 (SP) would protect, create and nourish a net total of 

2,162 acres (876 ha) of emergent wetlands which would reduce, to some undetermined level, 

the increased storm surge and wave potential at the hurricane protection system that would be 

expected with the loss of wetlands projected under the No Action Alternative. However, 

because the acreage of emergent wetlands, levee heights and alignments, shoreward depths, and 

storm characteristics all affect the height of storm surge, it is difficult to determine at this stage 

of scientific knowledge the effect of implementing the proposed action on storm surge around 

Lake Borgne (personal communication, Mr. Ty Wamsley, ERDC, April 24, 2007; personal 

communication, Mr. Van Stutts and Ms. Janice Hote, LACPR Hydrology Team, December 19, 

2007). Shoreline protection features would reduce storm wave action, which would encourage 

deposition of suspended sediments behind these features. 

ALTERNATIVE 2: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.9.1.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts to flow and water levels would primarily be 

associated with incremental impacts of similar wetland restoration and shoreline protection 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 44

features in and near the project area as well as throughout coastal Louisiana. Cumulative 

impacts would be the synergistic effect with the additive combination of impacts and benefits 

for overall net acres created, nourished, and protected by other Federal, state, local, and private 

restoration efforts as summarized in Section 4.1.4 and Table 4.2. The WRDA 2007 authorized 

diversion at or near Violet, Louisiana, would introduce up to 15,000 cfs (425 m3

/sec) into the 

project area. Coupled with the closure structure on the MRGO channel at the Bayou La Loutre 

ridge, this feature would freshen the surrounding waters, albeit to an unknown extent, and 

slightly alter flow patterns in and near the project area. Alternative 10 (SP) would work 

synergistically with these projects to provide additional protection for the land bridge. 

Protecting wetlands (preventing their loss) has a net effect of lowering storm surge and wave 

heights compared to a future condition with extensive wetland loss (personal communication, 

Mr. Ty Wamsley, ERDC, April 24, 2007; and personal communication, Mr. Van Stutts and 

Ms. Janice Hote, LACPR Hydrology Team, December 19, 2007). In addition, the more 

complete protection of the land bridge would help to prevent the increased water exchange 

between Lake Borgne and the MRGO channel expected with the No-Action Alternative. 

ALTERNATIVE 2: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

4.9.2 Sediment 

4.9.2.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on sediment. Indirect impacts of not implementing 

wetland creation/nourishment and shoreline protection features would result in the persistence 

of existing conditions with land loss continuing at the same or increased rates and sediments 

being transported out of the area and into the open Gulf. Cumulative impacts would be the 

synergistic effect of the No-Action Alternative on sediment with the additive combination of 

similar wetland degradation and wetland loss impacts to sediment throughout coastal Louisiana, 

as well as the benefits and impacts of other state and Federal projects in the vicinity, as detailed 

in Section 4.1.1 and Table 4.2. 

4.9.2.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Implementing the wetland creation and nourishment features for 

this alternative would require a total of 9,700,000 cy (7,406,454 cubic meters) of sediments 

removed from four different borrow sites over a total of 1,850 acres (750 ha) of Lake Borgne 

water bottoms. Borrow sites would be dredged with relatively shallow depths (ten to 20 ft [3.0 

to 6.1 m]) below the existing water bottom. However, borrow area would eventually refill due 

to the high rates of shoreline erosion and coastal land loss throughout the Lake Borgne and 

Pontchartrain Basin. 

Dredging floatation access would impact a total of 118.3 acres (47.9 ha) of Lake Borgne water 

bottoms. However, sediments dredged for floatation access would be used, to the maximum 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 45

extent practicable, for wetland creation and nourishment or temporarily sidecast and later 

returned to the access channel following completion of construction. 

ALTERNATIVE 2: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP), except that only one borrow site would be impacted. 

ALTERNATIVE 3: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.9.2.3 Future With Project Condition – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of emergent wetlands that would 

increase the sediment trapping capabilities of the wetlands in the Golden Triangle and Shell 

Beach compared to the No Action Alternative. Shoreline protection features would reduce the 

wave energy of the water between the dike and the shoreline, inducing settlement and accretion 

of suspended sediments between the foreshore dike and the shoreline due to reduced water 

movement in the protected area. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP), with the 

following exceptions. Alternative 2 would not construct a saline marsh creation and 

nourishment feature at Shell Beach; nor would it borrow (hydraulically dredge) material from 

the eastern lobe of Lake Borgne. 

ALTERNATIVE 3: Indirect impact would be similar to those described for 

Alternative 10 (SP). 

4.9.2.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts to sediments would primarily be associated 

with incremental impacts of similar shoreline protection and wetland creation and nourishment 

features. Cumulative impacts would be the synergistic effect with the additive combination of 

impacts and benefits for overall net acres created, nourished, and protected by other Federal, 

state, local, and private restoration efforts as summarized in Section 4.1.4 and Table 4.2. 

Alternative 10 (SP) would synergistically interact with these projects to provide more complete 

protection for the land bridge, that in turn, would provide a greater level of storm surge 

reduction in the project area than would be expected with the loss of wetlands projected under 

the No Action Alternative. Additionally, the more complete protection of the land bridge will 

help to prevent the increased water exchange between Lake Borgne and the MRGO channel 

expected with the No-Action Alternative, which would have the net effect of increasing erosion 

and sediment loss from the project area. 

ALTERNATIVE 2: Cumulative impacts would be similar to those described for 

Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to those described for 

Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 46

4.10 WATER QUALITY RESOURCES 

4.10.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on water quality. Indirect impacts of not 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions. Without implementation of wetland 

creation/nourishment and shoreline protection features, the current water quality conditions 

would persist, coastal wetlands would still be affected by natural and man-made factors that 

would have both beneficial and detrimental effects on water quality conditions. Emergent 

wetland plants would continue to diminish as land loss and subsidence convert marshes to open 

water. Emergent wetland plants may serve to absorb and transform pollutants from the air and 

water; their loss may reduce this ability. 

Wastewater and polluted storm-water runoff from developed areas enter the MRGO and Lake 

Borgne from many different sources. Both total and fecal coliform, indicators of bacterial 

pollution, have consistently exceeded the applicable criteria of 70 and 14 counts per 

100 milliliters, respectively. Coliform levels observed at other locations along the channel have 

usually exceeded the criteria, indicating a widespread area of water and emergent wetlands that 

are subject to bacterial pollution. This is expected to continue in the future. 

Dissolved oxygen levels at Bayou Dupre have measured consistently above the minimum state 

standard and EPA criteria levels. With rare exceptions, the pH measurements also have been 

within the desirable range of 6.5 to 9.0. Toxic substances, including heavy metals and synthetic 

organics, have been measured above EPA criteria levels, but no patterns consistently exceeding 

the criteria for particular substances have been observed. Existing programs, such as the 

National Discharge Elimination System (NPES); LDEQ’s Nonpoint Source Pollution Program; 

LDNR’s Coastal Nonpoint Pollution Program; Total Maximum Daily Loads (TMDLs) would 

continue. The Lake Pontchartrain Basin Foundation (LPBF) activities, such as water quality 

monitoring, habitat protection, environmental education, and public events and outreach 

(personal communication, Ms. Andrea Bourgeois, LPBF, 2004) would continue. 

The programs discussed above would continue to develop or remain in place under the futurewith or future-without project conditions in order to ensure protection of Louisiana’s public 

health and natural resources. Other efforts that would probably improve water quality 

conditions are existing and reasonably foreseeable Federal, state, local, and private ecosystem 

restoration projects. Water quality conditions could possibly improve with all of these 

programs in place. However, the continued degradation under the No-Action Alternative would 

likely result in a decline in overall water quality within project area, because other activities that 

would have adverse effects on water quality would also continue to occur in the future, such as 

continued urban storm-water runoff and the discharge of untreated or poorly-treated sewerage. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on water 

quality with the additive combination of similar water quality impacts throughout coastal 

Louisiana, as well as the benefits and impacts of other state and Federal projects in the vicinity, 

as detailed in Section 4.1.1. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 47

4.10.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): During construction, there would be an increase in turbidity, 

suspended sediments, BOD, and water temperature and a decrease in DO. These impacts would 

be associated with dredging, placement of borrow material, and placement of rock. However, 

these impacts would be temporary and localized. Additionally, the borrow material would be 

placed in existing open water habitats, so that once the material has dispersed and settled to 

project goal elevation, water quality would return to ambient conditions. 

ALTERNTIVE 2: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP), with the following exceptions. This alternative has one less emergent 

wetland creation and nourishment feature; therefore, water quality would not be directly 

impacted in the Shell Beach area from hydraulic dredging. However, water quality would be 

directly impacted to a lesser extent from the construction of floatation access channels in this 

area. 

ALTERNATIVE 3: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.10.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): There would be a potential for temporary nutrient enrichment 

associated with suspended sediments during dredging and fill placement operations that could 

possibly lead to localized increased algae blooms. Localized short-term increases in turbidity 

could possibly lead to temporary displacement of estuarine organisms. Borrow activities could 

slightly increase the temperature of the ambient water by increasing the solar absorption 

through increased suspended sediments. However, any such impacts are expected to be minor 

and conditions would return to ambient following construction. 

Indirect impacts of wetland creation/nourishment and shoreline protection would primarily 

provide long-term improvement of water quality because emergent wetlands serve as natural 

filters for improving water quality (Day et al., 1998). By protecting the critical land bridge 

separating Lake Borgne from the MRGO channel, the Alternative 10 (SP) would help prevent 

the degradation of water quality in Lake Borgne that would likely occur as the land bridge is 

breached and eroded. 

Dissolved oxygen deficits (hypoxia and anoxia) may develop in water bodies where there is a 

combination of organic material accumulation and limited water column circulation. Organic 

material is supplied to the system either as autochthonous or allochthonous inputs (such as 

senescent plankton or marsh detritus), and may accumulate in sediments underlying the water 

column. Decomposition of organic material in underlying sediments consumes dissolved 

oxygen from the water column, while the supply of dissolved oxygen is largely dependent on 

the downward mixing of oxygenated surface waters. Downward mixing of surface waters is 

facilitated by wind and wave energy, cooling of surface waters, and circulation within a water 

body. When there is insufficient energy for mixing, density discontinuities may develop that 

divide the water column into isolated strata. Isolation of processes consuming oxygen in the 

lower strata from processes supplying oxygen in the upper strata may result in short-term 

hypoxic events, more persistent hypoxia, or anoxia in severe cases. Water bottom contours may 

further restrict circulation between the strata and within a water body, or act as a trap for dense 

waters that are more resistant to exchange with the upper strata. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 48

Borrow pit dimensions may influence the potential formation of dissolved oxygen deficits. The 

tendency for a pit to accumulate organic material can be reduced by: 1) limiting the depth of the 

pit; 2) increasing the pit’s surface area; and, 3) decreasing side-slopes that transition from the pit 

to adjacent water bottoms. A shallow and broad “pan-shaped” borrow pit would facilitate 

circulation with adjacent waters thereby decreasing the likelihood that organic material would 

become entrained, and allow for periodic flushing of the pit during storm events. In contrast, 

narrow and deep pits would be less influenced by circulation in the overlying water column and 

would require greater energy for flushing of organic material. The tendency for density 

discontinuities to persist in water columns overlying the pit can also be reduced by limiting the 

depth of the pit. Shallower pits would require less energy to mix the water column from top to 

bottom than a deeper pit. A pan-shaped pit would further facilitate mixing with adjacent waters, 

reducing the likelihood that isolated pockets of dense water would develop or persist. 

Borrow pits in Lake Borgne that would be utilized as a sediment source for marsh creation 

projects would have dimensions restrictive of dissolved oxygen deficit formation. Borrow pits 

would be pan-shaped with large surface areas (230 to 1,070 acres [91 to 433 ha]) and relatively 

shallow depths (10 to 20 ft [3.0 to 6.1 m] below existing depth), and would gradually transition 

from adjacent water bottoms to project depth (side slopes between 1 vertical : 2 horizontal and 

1 v : 3 h). The borrow pits would be located some distance from sources of allochthonous 

inputs (3,000 ft [914 m] minimum distance from the shoreline or tidal passes), and 

sedimentation rates within the project area are relatively low without the presence of 

predominant organic layers. Moreover, circulation within Lake Borgne is not restricted by 

physical barriers, and storm fronts generating considerable wave energy commonly occur. 

Proposed borrow pit dimensions combined with observed characteristics of the project area are 

therefore not expected to favor the formation of dissolved oxygen deficits. 

ALTERNATIVE 2: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.10.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts to water resources would primarily be 

associated with incremental impacts of similar wetland creation, nourishment, and shoreline 

protection features. Cumulative impacts would be the synergistic effect with the additive 

combination of impacts and benefits for overall net acres created, nourished, and protected by 

other Federal, state, local, and private restoration efforts as summarized in Section 4.1.4. 

Alternative 10 (SP) would work cooperatively with those projects to provide more complete 

protection for the land bridge, which would help preserve water quality in the project area. 

ALTERNATIVE 2: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 49

4.10.5 Salinity Regimes 

4.10.5.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on salinity regimes. Indirect impacts of the No 

Action Alternative would result in the persistence of existing conditions including impacts 

associated with the authorized MRGO closure structure at Bayou La Loutre (USACE, 2008); 

impacts associated with the authorized improvements to the Greater New Orleans Hurricane and 

Storm Damage Risk Reduction System (GNOHSDRRS; USACE, 2008); and impacts 

associated with the diversion authorized by WRDA 2007 at or near Violet, Louisiana. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on salinity 

regimes with the additive combination of similar water quality impacts throughout coastal 

Louisiana, as well as the benefits and impacts of other state and Federal projects in the vicinity, 

as detailed in Section 4.1.1 and Table 4.2. 

The authorized MRGO closure structure at Bayou La Loutre is anticipated to be constructed 

before the beginning of the 2009 hurricane season (USACE, 2007). The reduced vessel traffic 

along the MRGO would not affect salinities in the project area. However, the MRGO closure 

structure would be expected to reduce salinities in the project area by up to 6.6 ppt (USACE, 

2007). 

The authorized improvements to the GNOHSDRRS would consist of approximately two miles 

of new GNOHSDRRS extending from the Michoud floodwall north of the GIWW to the levee 

on the west side of the MRGO (Figure 3.5). The proposed action would provide 26 ft (7.9 m) 

of GNOHSDRRS protection, including two ft of structural superiority to account for the 

anticipated rise in sea level and subsidence in the local area. The GNOHSDRRS would cross 

the GIWW, Bayou Bienvenue, the MRGO, and the Golden Triangle marsh. The proposed 

action would consist of a flood control sector gate (150 ft by 16 ft; 45.7 m by 4.9 m) and bypass 

barge gate (150 ft by 16 ft; 45.7 m by 4.9 m) on the GIWW approximately 1,150 ft (351 m) east 

of the Michoud Canal, a new navigable flood control sector gate at Bayou Bienvenue (56 ft by 

eight ft; 17.1 m by 2.4 m), a braced concrete wall across the MRGO (approximately 2,700 ft 

[823 m] southeast of the existing Bayou Bienvenue flood control structure), and a concrete 

floodwall across the marsh between these waterways. The existing Bayou Bienvenue flood 

control structure would be maintained in its existing condition and could be used to regulate 

high tide events in the Central wetlands. 

Preliminary modeling results (USACE 2008) have shown a slight (± 0.1 part per thousand [ppt]) 

change in salinity inside the Chalmette wetlands during the wet season and adjacent to the 

MRGO closure during the dry season. The proposed gate structures at Bayou Bienvenue and 

the GIWW are designed to allow for continued tidal exchange except in times of impending 

storm threat or during maintenance periods when the gates would be closed. This would allow 

for normal salinity regimes to be maintained. According to IER #11 salinity stratification is 

expected to be reduced north of the total closure structure, which is anticipated to reduce 

salinity stratification in Lake Pontchartrain. It is anticipated that the most significant changes in 

salinity would be as a result of construction of the total closure structure on the MRGO south of 

Bayou La Loutre and not as a result of any structures constructed as part of the GNOHSDRRS 

(USACE, 2008). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 50

Additionally, the WRDA 2007 authorized diversion at or near Violet, Louisiana, would 

introduce up to 15,000 cfs (425 m3

/sec) into the project area. Coupled with the closure structure 

on the MRGO channel at the Bayou La Loutre ridge, this feature would further freshen the 

surrounding waters, albeit to an unknown extent. 

4.10.5.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): The proposed action would not directly impact salinity regimes. 

Salinity regimes would be similar to the No-Action Alternative. 

ALTERNATIVE 2: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.10.5.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIE 10 (SP): Indirect impacts would be similar to the No-Action Alternative. 

ALTERNATIVE 2: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts of this alternative would be similar to those described for 

Alternative 10 (SP). 

4.10.5.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts to salinity regimes would be similar to those 

described under the No Action Alternative, with the following exceptions. Alternative 10 (SP) 

would work synergistically and in an additive combination of impacts with other Federal, state, 

local, and private restoration efforts as summarized in Section 4.1.4 and Table 4.2 as well as 

with the following authorized actions: MRGO closure (USACE 2007); the WRDA 2007 

authorized diversion at or near Violet, Louisiana; and improvements to the GNOHSDRRS 

(USACE 2008). These synergistic interactions would provide more complete protection for the 

land bridge and begin to address the effects of salt-water intrusion into the area. 

ALTERNATIVE 2: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts of this alternative would be similar to those described 

for Alternative 10 (SP). 

4.11 RECREATIONAL RESOURCES 

4.11.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on recreational resources. Indirect impacts of not 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions including the continued conversion of existing marsh to 

open water habitats, and the continued bankline erosion and sloughing of the Lake Borgne 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 51

shoreline. The recreation needs identified by the 1993–1998 Louisiana Statewide 

Comprehensive Outdoor Recreation Plan (SCORP) in this area may be expected to become 

greater, particularly for recreation opportunities dependent on estuarine species. 

Predicted land loss may adversely impact recreation opportunities (USACE, 2004). Most of the 

recreational activities that occur in the project area consist of hunting, fishing, wildlife 

observation, and general enjoyment of the aesthetic marsh environment. Recreational resources 

in the region that would most likely be affected in the future without action are those related to 

loss of wetlands and habitat diversity. Wildlife abundance is directly related to the amount of 

wetlands present. As wetland degradation and the high rates of land loss continues throughout 

the area, wildlife abundance would continue to decrease. The local abundance of resident 

transitional wetland-dependent wildlife would likely decrease as these species relocate to find 

more suitable transitional wetland habitats. Migratory birds would be required to find other, 

more suitable stopover habitats on their trans-Gulf migrations. With the continued conversion 

of transitional estuarine wetlands to open water, estuarine fishery abundance and diversity 

would be expected to decline over time. Lower quality fishery spawning, nursery, and foraging 

habitat would translate to a decline in sport fishing success in the future. As the usage by game 

species decline, so would the hunting opportunities. As usage by migratory birds decline, so 

would the opportunities for viewing. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on recreation 

resources with the additive combination of similar recreation 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, as detailed in Section 4.1.1 and Table 4.2. 

4.11.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): The primary direct impacts on recreational resources would result 

from the project area being temporarily unavailable during construction. In addition, there 

would be a temporary decrease in the quality of recreational opportunities as the wetland 

creation and nourishment sites re-vegetates, usually within 9 to 12 months, following 

completion of construction. Portions of the proposed action (Golden Triangle marsh creation 

and nourishment feature) would be constructed on the Bayou Sauvage National Wildlife 

Refuge. It is anticipated that the proposed action would positively increase opportunities for 

recreation on this portion of the Refuge, as well as provide important and essential fish and 

wildlife habitats. 

ALTERNATIVE 2: Impacts similar to Alternative 10 (SP) with the following exceptions: 

Placement of ACM on the shoreline would directly and permanently impact vegetation that 

could be used by wildlife along the southern bankline of the MRGO channel. 

ALTERNATIVE 3: Impacts similar to Alternative 10. 

4.11.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Alternative 10 (SP) would protect, create and nourish a net total of 

2,162 acres (874 ha) of transitional estuarine wetlands, including a portion of the Bayou 

Sauvage National Wildlife Refuge located on the Golden Triangle. Following construction, 

these transitional estuarine wetlands would provide important and essential fish and wildlife 

habitats that would contribute to restoring the base of organisms used for recreational activities 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 52

such as fishing, bird watching and hunting. Increased recreation activities would come from 

expansion of new vegetative habitat on newly created areas and the relief from flooding 

frequency stressors that those areas would afford existing habitats. Creating wetlands and 

reducing loss rates for the project area may also protect nearby recreational infrastructure in the 

community of Yscloskey, such as boat launches. 

Wildlife-dependent recreation activities would be maintained and possibly increased. 

Recreation activities dependent upon wetland habitats would be maintained and possibly 

increased including: hunting, fishing and bird watching. There would be a decrease in boat 

traffic accessibility through the Lake Borgne shoreline protection features; however, such 

access to the Lake Borgne shoreline would still be available from the banks of existing 

waterways, which would remain open. Fishing and hunting activities could continue in areas 

near the project sites. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.11.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect of 

implementing Alternative 10 (SP) with the additive combination of impacts and benefits for 

overall net acres created, nourished, and protected by other Federal, state, local, and private 

restoration efforts as summarized in Section 4.1.4 and Table 4.2. Alternative 10 (SP) would 

work synergistically with those projects to provide more complete protection for the land 

bridge, which would continue to provide wetland-dependent recreational opportunities in the 

project area. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.12 PUBLIC LANDS 

4.12.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on public lands. Indirect impacts of not 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions including the continued conversion of existing marsh to 

open water habitats, and the continued bankline erosion and sloughing of the Lake Borgne 

shoreline. Under the No Action Alternative, recreation opportunities within the Bayou Sauvage 

NWR dependent on estuarine species would be expected to decline. 

Predicted land loss may adversely impact recreation opportunities on public lands within the 

project area (USACE, 2004). Most of the recreational activities that occur in the Bayou 

Sauvage NWR consist of hunting, fishing, wildlife observation, and general enjoyment of the 

aesthetic marsh environment. Public lands in the region that would most likely be affected 

under the No Action Alternative are those related to the loss of wetlands and habitat diversity. 

Wildlife abundance is directly related to the amount of wetlands present. As wetland 

degradation and the high rates of land loss continues throughout the area, wildlife abundance 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 53

would continue to decrease. The local abundance of resident transitional wetland-dependent 

wildlife would likely decrease as these species relocate to find more suitable transitional 

wetland habitats. Migratory birds would be required to find other, more suitable stopover 

habitats on their trans-Gulf migrations. With the continued conversion of transitional estuarine 

wetlands to open water, estuarine fishery abundance and diversity would be expected to decline 

over time. Lower quality fishery spawning, nursery, and foraging habitat would translate to a 

decline in sport fishing success in the future. As the usage by game species decline, so would 

the hunting opportunities. As usage by migratory birds decline, so would the opportunities for 

viewing. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on public 

lands with the additive combination of similar impacts from wetland loss and degradation 

throughout coastal Louisiana on public lands, as well as the benefits and impacts of other state 

and Federal projects in the vicinity, as detailed in Section 4.1.1 and Table 4.2. 

4.12.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): The primary direct impacts on public lands would result from the 

project area being temporarily unavailable during construction. In addition, there would be a 

temporary decrease in the quality of recreational opportunities within the Bayou Sauvage NWR 

as the wetland creation and nourishment sites re-vegetates, usually within 9 to 12 months, 

following completion of construction. However, it is anticipated that the proposed action would 

positively increase opportunities for recreation on this portion of the Bayou Sauvage NWR, as 

well as provide important and essential fish and wildlife habitats. 

Implementing Alternative 10 (SP) would introduce 6.5 million cubic yards (5.0 million cubic 

meters) of material into the shallow open water areas of the Golden Triangle, creating and 

nourishing a total of 2,650 acres (1,074 ha) of wetlands, with a net benefit of 1,495 acres 

(608 ha) of wetlands over the 50-year period of analysis. This would increase the total acreage 

of wetlands within and near the Bayou Sauvage NWR, as well as convert open water EFH to 

intertidal marsh EFH. 

ALTERNATIVE 2: Impacts similar to Alternative 10 (SP), except that 2,850 acres (1,155 ha) 

would be created and nourished on the Golden Triangle through the introduction of 9.5 million 

cubic yards (7.3 million cubic meters) of material, with a net benefit of 1,685 acres (683 ha). 

ALTERNATIVE 3: Impacts similar to Alternative 10 (SP), except that 2,750 acres (1,114 ha) 

would be created and nourished on the Golden Triangle through the introduction of 7.4 million 

cubic yards (5.7 million cubic meters) of material, with a net benefit of 1,608 acres (651 ha). 

4.12.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Alternative 10 (SP) would protect, create and nourish a net total of 

1,495 acres (606 ha) of transitional estuarine wetlands in the Golden Triangle. Some of these 

wetlands would be located within that portion of the Bayou Sauvage NWR located on the 

Golden Triangle. Following construction, these transitional estuarine wetlands would provide 

important and essential fish and wildlife habitats that would contribute to restoring the base of 

organisms used for recreational activities such as fishing, bird watching and hunting. Increased 

opportunities for use of public lands would come from expansion of new vegetative habitat on 

newly created areas and the relief from flooding frequency stressors that those areas would 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 54

afford existing habitats. Additionally, creating wetlands and reducing loss rates for the 

wetlands within the Golden Triangle may increase the sustainability of the Bayou Sauvage 

NWR and the uses associated with it. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP) for the wetland 

creation feature. Additionally, the Golden Triangle shoreline protection feature would reduce 

the shoreline erosion of Lake Borgne, including a portion of the shoreline that is located within 

the Bayou Sauvage NWR boundary (Figure 2.1). The Golden Triangle shoreline protection 

feature would construct 17,700 lf (5,395 m) of foreshore rock dike from Bayou Bienvenue to 

Bayou Gentilly in Lake Borgne. This would provide a net benefit of 115 ac (47 ha). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.12.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect of 

implementing Alternative 10 (SP) with the additive combination of impacts and benefits for 

overall net acres created, nourished, and protected by other Federal, state, local, and private 

restoration efforts as summarized in Section 4.1.4 and Table 4.2. Alternative 10 (SP) would 

work synergistically with those projects to provide more complete protection for the wetlands 

within the Golden Triangle, including those in the Bayou Sauvage NWR, which would continue 

to provide wetland-dependent recreational opportunities in the project area. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP), except that 

the additional Golden Triangle shoreline protection feature would provide additional synergistic 

effects with the Golden Triangle wetland creation feature to more fully protect the wetlands of 

the Bayou Sauvage NWR. 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.13 CULTURAL RESOURCES INCLUDING NATIONAL 

REGISTER LISTINGS 

4.13.1 The No-Action Alternative 

Without implementation of wetland creation and nourishment and shoreline protection 

measures, the current conditions would persist, including continued conversion of current marsh 

to open water habitats, continued bankline erosion and sloughing of the shoreline. The erosion 

caused by natural forces and human activity would continue to adversely affect existing cultural 

resources in the project area. The loss of land along the MRGO and Lake Borgne threatens the 

existence and integrity of these sites. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on cultural 

resources with 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, as detailed in Section 4.1.1. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 55

4.13.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Shoreline stabilization would prevent further land loss and erosion 

in the project area behind those features. This would benefit cultural and historical resources in 

the area by preventing the erosion that threatens their existence. A Cultural Resources Survey 

has been conducted to identify sites of importance that may or may not be directly impacted by 

dredging and shoreline stabilization and wetland creation activities. Direct impacts to cultural 

resources could result from construction activities near restoration features. Direct impacts on 

historic or prehistoric resources may also occur at the offshore borrow sites if such resources are 

present. Dredging may impact any prehistoric or historic shipwrecks in the area. Depositing 

sediment on top of a known site can change the environment in which a site has survived, but 

would most likely provide additional protection to the site. Where sites are identified, 

alterations to the design would be implemented to minimize impacts to the sites. Project 

planning will be conducted in such a manner to avoid impacts to any historic properties. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.13.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): The proposed action will have no indirect impact on historic 

properties. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.13.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4. This alternative plan would work cooperatively with those projects to provide 

more complete protection for the land bridge, which would continue to provide protection to the 

cultural resources in the project area. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.14 AESTHETICS 

4.14.1 The No-Action Alternative 

The visual complexity surrounding the project area is related to its fragmented and remote 

marshes, bayous, wetlands, ridges, and levees that provide pleasing aesthetic viewscapes to the 

public eye. Without implementation of wetland creation and shoreline protection measures, 

continued bankline erosion and sloughing of the shoreline and conversion of existing 

fragmented wetlands to open water habitats would persist. This would result in and the eventual 

breaching of the Lake Borgne/MRGO land bridge, and reduce the protection for existing 

viewscapes of Bayou La Loutre’s natural ridge habitat. Degradation of the land bridge between 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 56

Lake Borgne and the MRGO would convert existing heterogeneous viewscapes of emergent 

wetlands interspersed with open water to more open water viewscapes. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on aesthetic 

resources with 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, as detailed in Section 4.1.1 and Table 4.2. 

4.14.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Viewscapes would be disturbed by construction activities and the 

use of rock as a shoreline protection structure. There may be some perceived visual disturbance 

as an unnatural rock dike structure is placed in front of a natural shoreline. Even though the 

shoreline protection features would remain visually disruptive, the visual benefits surrounding 

the protection of visually complex wetlands viewscapes would outweigh the slight negative 

impact on aesthetics. 

The immediate effects of construction activities would also temporarily reduce the aesthetic 

value of Bayou Bienvenue, due to large expanses of marsh platform adjacent to it that would 

initially be unvegetated. Nevertheless, wetland vegetation would re-colonize the area within 

nine to twelve months, thereby increasing the scenic value of Bayou Bienvenue by providing 

increased visual complexity within the project area. 

With the implementation of any shoreline protection feature, the viewscapes around the project 

area would experience limited short-term disruption imposed by the working activities of the 

floating dredge plant. These minor impacts would be localized and temporary. The project area 

should quickly stabilize, and the newly created, nourished and protected emergent wetlands 

would provide new high quality viewscapes as well as protect existing ones. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP) with the following 

exception: installation of ACM would require grading and clearing of vegetation for the work 

corridor which would negatively impact the viewscape associated with the wetlands along the 

MRGO. The ACM would provide a lower quality viewscape based on its scale and contrast 

with the project area’s more natural surrounding environment. 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.14.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Indirect impacts to visual resources would primarily result from 

newly created high quality emergent wetland viewscapes that would provide a long-term visual 

enhancement of an area that is presently experiencing a decline in visual complexity. 

ALTERNATIVE 2: Indirect impacts are similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts are similar to Alternative 10 (SP). 

4.14.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 57

Section 4.1.4 and Table 4.2. Alternative 10 (SP) would work synergistically with those 

projects to provide more complete protection for the land bridge, which would increase the 

quality of the visually complex viewscapes throughout the project area. Cumulative impacts of 

maintaining appealing viewscapes would also support eco-tourism as one travels Louisiana’s 

Scenic Byways and remote areas of visual interest. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.15 NOISE 

4.15.1 The No-Action Alternative 

There would be no direct, indirect, or cumulative impacts of the No-Action Alternative on 

noise. Not implementing wetland creation/nourishment and shoreline protection features would 

result in the persistence of existing conditions. The project area is a remote and uninhabited 

marsh. The noise from nearby urban areas has little, if any, impact on the project area. This is 

expected to continue in the future. 

4.15.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Construction activities associated with implementing 

Alternative 10 (SP) would temporarily increase the noise level in the project area. However, the 

project area is remote and unpopulated so the noise level would not affect any nearby human 

communities. Once construction activities are completed, noise levels would return to preconstruction conditions. 

Potential noise impacts concerns may be expected 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 regulations for Occupational Noise Exposure 

(29 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. 

Localized and temporary noise impacts would likely result in wildlife and fishery resources 

temporarily leaving the project area during construction activities. In some instances, noise 

impacts may directly impact fish and wildlife species. These organisms would generally avoid 

the construction area. However, tolerance of unnatural disturbance varies among wildlife. 

Therefore identifying the key species of concern and following feasible administrative and or 

engineering controls, determining and implementing appropriate buffer zones, and 

implementing construction activity windows, shall address these issues. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP) with the following 

exception: The grading activities associated with ACM placement would temporarily raise the 

noise level along the south bankline of the MRGO channel. 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 58

4.15.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Noise may temporarily cause some local fish and wildlife species 

to relocate during construction activities. However, indirect impacts due to noise are expected 

to be localized, temporary, and minor in nature. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.15.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): The cumulative impacts would principally be related to the 

potential short-term disruption of fish and wildlife species and similar impacts by other similar 

Federal, state, local and private restoration activities as well as other human-induced noise 

disruptions to these organisms. Cumulative impacts would be a synergistic result over and 

above the additive combination of impacts and benefits of this alternative and other Federal, 

state, local, and private restoration efforts as summarized in Section 4.1.4 and Table 4.2. Longterm adverse cumulative impacts due to noise levels are not expected with implementation of 

Alternative 10 (SP). 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.16 AIR QUALITY 

4.16.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on air quality. Indirect impacts of not implementing 

wetland creation/nourishment and shoreline protection features would result in the persistence 

of existing conditions. The project area is a remote and uninhabited marsh. Air quality would 

continue to be subject to institutional recognition and further regulations. However, air quality 

in the project area would likely decline for the following reasons: continued population growth, 

further commercialization and industrialization, increased numbers of motor vehicles, and 

increased emissions from various engines. These impacts would be coupled with the continued 

loss of Louisiana coastal wetland vegetation that would no longer be available to remove 

gaseous pollutants. Nevertheless, air quality degradation is not anticipated to be a significant 

problem in the project area under the No-Action Alternative during the 50-year period of 

analysis. Cumulative impacts would be the synergistic effect of the No-Action Alternative on 

air quality with the additive combination of similar air quality 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, as detailed in Section 4.1.1 and 4.2. 

4.16.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Direct impacts to ambient air quality would be temporary and 

localized, resulting primarily from the emissions of construction equipment within the project 

area. An air applicability determination analysis was performed based upon direct emission for 

estimated construction hours. It has been the experience of the CEMVN that total emissions for 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 59

each work item separately (or even when all work items are summed) generally do not exceed 

the threshold limit applicable to volatile organic compounds (VOC) for parishes where the most 

stringent requirement (50 tons per year [49.38 metric tons per year] in serious non-attainment 

parishes) is in effect. The VOC emissions for the proposed construction would total 

approximately 42.18 tons (42.66 metric tons) for all construction features. The construction 

would take from 18 to 24 months to complete, so that VOC emissions would be 24.09 to 

28.12 tons per year (23.79 to 27.77 metric tons per year). These emissions would be classified 

as de minimus and no further action would be required. It is likely that indirect emissions, if 

they occur, would be negligible. Additionally, these effects to air quality would be temporary, 

and air quality would return to pre-construction conditions shortly after the completion of 

construction activities. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.16.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of emergent wetlands that would 

help to improve local air quality by reducing particulates and gaseous air pollutants. Studies of 

the effects of common wetland plants on removing or reducing air pollution in the coastal 

Louisiana area have yet to be done. However, it is reasonable to extrapolate from the findings 

of researchers such as David J. Nowak (personal communication, Mr. David J. Nowak, Project 

Leader, USDA Forest Service, Northeastern Research Station, 5 Moon Library, SUNY-CESF, 

Syracuse, New York) that the trees and vegetation in coastal Louisiana would improve air 

quality. Improvement of air quality would provide positive benefits for humans overall, 

although this relative difference will be minimal because of the size of the project area and 

distance from population centers. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.16.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4 and Table 4.2. Alternative 10 (SP) would work synergistically with those 

projects to provide more complete protection for the land bridge and greater longevity for 

wetlands in the project area. Although unlikely to greatly impact air quality alone, the project 

area would provide some air quality improvement from the cumulative effects of creating, 

nourishing and protecting these wetlands in conjunction with other restoration efforts. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 60

4.17 SOCIOECONOMIC AND HUMAN RESOURCES 

4.17.1 Population 

4.17.1.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct, indirect, or cumulative impacts on human populations. Not 

implementing wetland creation/nourishment and shoreline protection features would result in 

the persistence of existing conditions. The project area is a remote and uninhabited marsh and 

there are no human populations within the project area. 

4.17.1.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): There are no human populations within the project area, and the 

proposed action would have no direct effects outside of the project area. Hence this alternative 

would not be expected to have any direct effects on nearby populations. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.17.1.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): There are no human populations within the project area, and the 

proposed action would have minimal indirect effects outside of the project area. Hence this 

alternative would not be expected to have any indirect effects on nearby populations. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.17.1.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): There are no human populations within the project area. Hence this 

alternative would not be expected to have any cumulative effects on nearby populations. 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.2 Infrastructure 

4.17.2.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on infrastructure. Indirect and cumulative impacts 

of not implementing wetland creation/nourishment and shoreline protection features would 

result in the persistence of existing conditions including impacts related to continuing coastal 

land loss. Cumulative impacts would be the synergistic effect of the No-Action Alternative on 

infrastructure with the additive combination of similar infrastructure impacts from wetland loss 

and degradation throughout coastal Louisiana, as well as the benefits and impacts of other state 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 61

and Federal projects in the vicinity, as detailed in Section 4.1.1 and Table 4.2. The projected 

continued coast wide decline of emergent wetlands would contribute to the deterioration of 

substrate upon which infrastructure features (e.g., oil, gas and water pipelines and telephone and 

electric transmission wires) are constructed. The effects of land loss and degradation could lead 

to increased costs for maintaining and repairing existing infrastructure. However, these impacts 

would be somewhat offset by construction of the authorized construction of the MRGO closure 

structure near Bayou La Loutre in St. Bernard Parish, Louisiana (USACE 2007); the WRDA 

2007 authorized diversion of up to 15,000 cfs (425 m3/sec) at or near Violet, Louisiana; and the 

shoreline protection provided by the CWPPRA PO 30 project and similar projects. 

4.17.2.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Implementing this alternative would have no direct impacts on 

existing infrastructure in the project area. Construction practices would be implemented to 

avoid and minimize any potential construction-related impacts to existing infrastructure (e.g., 

pipelines, etc.). 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.2.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of emergent wetlands that would 

reduce shoreline erosion and land loss thereby reducing the need for relocation, repair or 

replacement of infrastructure compared to the No-Action Alternative. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.17.2.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4 and Table 4.2. Alternative 10 (SP) would work synergistically with those 

projects, especially the authorized MRGO closure structure at Bayou La Loutre (USACE 2007) 

and the diversion authorized by WRDA 2007 at or near Violet, Louisiana, to provide more 

complete protection for the land bridge, which would continue to provide protection to existing 

infrastructure in the project area. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 62

4.17.3 Employment and Income 

4.17.3.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on employment or income. Indirect impacts would 

result in the persistence of existing conditions including continued wetland loss and degradation 

of the Lake Borgne-MRGO land bridge. This continued wetland loss would have localized 

impacts on employment and income. For example, the effects of wetland loss and degradation 

of the land bridge would lead to a decline in transitional wetland habitats, an important EFH 

which, in turn, could lead to some undetermined level of economic decline in local fisheryrelated employment and income. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on 

employment and income with the additive combination of similar employment and income 

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, as detailed in Section 4.1.1 and

Table 4.2. Although the projects and programs identified in Section 4.1.1 and Table 4.2, would 

provide some undetermined level of positive benefits to employment and income, these projects 

would not be sufficient to offset the impacts of the long-term coastwide wetland losses 

projected for Louisiana (USACE, 2004). Coastal Louisiana's continued wetland loss and the 

related depletion of wetland-dependent natural resources (fisheries, oysters, hunting, recreation, 

etc.) could likely result in a decline of job opportunities and personal income throughout rural 

coastal areas (USACE, 2004). Other supporting economic activities such as marinas, bait and 

tackle shops could also be adversely impacted by the degradation and eventual loss of these 

wetlands and wetland-dependent resources. 

The loss of storm buffering provided by wetlands could result in the need for greater 

expenditures for maintaining and repairing existing infrastructure. This could provide localized 

employment and income benefits. However, these benefits would likely be offset by the 

expenditures necessary for maintaining, upgrading and constructing new hurricane and flood 

protection. 

4.17.3.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): There may be a temporary increase in local employment due to the 

construction activities related to implementation of Alternative 10 (SP). 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.3.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of emergent wetlands that would 

benefit, to some undetermined level, local employment in wetland-dependent jobs such as 

commercial and recreational fisheries, ecotourism; as well as provide benefits for supporting 

economic activities such as marinas, bait and tackle shops, and others. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 63

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.17.3.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4 and Table 4.2. Alternative 10 (SP) would work synergistically with these other 

projects and programs to provide not only more complete protection for the Lake BorgneMRGO land bridge but also help support coast wide wetland-dependent employment. 

However, this would not offset the widespread negative cumulative impacts to employment and 

income described under the No Action Alternative (Section 4.17.3.1 above). 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP). 

4.17.4 Navigation 

4.17.4.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on navigation. Indirect impacts would result in the 

persistence of existing conditions including deauthorization of the MRGO from the Gulf of 

Mexico to Mile 60 at the southern bank of the GIWW and construction of the authorized 

MRGO closure structure at Bayou La Loutre; construction of the authorized improvements to 

the GNOHSDRRS including a flood control sector gate and bypass barge gate on the GIWW, a 

new navigable flood control sector gate at Bayou Bienvenue, a braced concrete wall across the 

MRGO located southeast of the existing Bayou Bienvenue flood control structure, and a 

concrete floodwall across the marsh (Golden Triangle area) between these waterways. The 

existing Bayou Bienvenue flood control structure would be maintained in its existing condition. 

Additionally, the WRDA 2007 authorized diversion at or near Violet, Louisiana, would 

introduce up to 15,000 cfs (425 m3

/) into the project area. 

Deauthorization and closure of the MRGO would reduce navigation in the MRGO. Navigation 

and channel maintenance would continue in the GIWW, which runs along the northwestern 

edge of the project area. Continued degradation and loss of emergent wetlands in the project 

area would contribute to increased sedimentation and maintenance of the GIWW navigation 

channel. As the wetlands in the Golden Triangle fragment and convert to open water, the 

protection afforded to the GIWW from Lake Borgne wind-driven waves would be reduced. 

Some vessels utilizing the GIWW, especially barge traffic, would be subjected to more open 

water conditions as the land bridge continues to erode, thereby exposing this waterway directly 

to Lake Borgne. The integrity of the GIWW as an inland, protected waterway is paramount to 

its function for navigation and commerce. Costs to maintain this protection would likely 

increase if the land bridge breached. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on navigation 

with the additive combination of similar navigation 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, as detailed in Section 4.1.1 and Table 4.2. As Louisiana’s coastal 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 64

wetlands continue to fragment and convert to open water, the protection wetlands provide to 

inland waterways from wind-driven waves would be reduced. Inland vessels, such as barge 

traffic, would be subjected to more open water marine-like conditions. 

4.17.4.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): This alternative would have no direct impacts on navigation. 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.4.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of emergent wetlands that would 

maintain the Lake Borgne-MRGO land bridge. The land bridge would protect adjacent 

waterways, such as the GIWW, from waves propagated through the lake, thus providing a safer 

route for inland water-borne traffic. 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.4.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4 and Table 4.2. Alternative 10 (SP) would work synergistically with those 

projects to protect adjacent waterways, such as the GIWW, from waves propagated through the 

lake, thus providing a safer route for inland water-borne traffic. However, the widespread 

coastal land loss and subsequent impacts to navigation described under the No Action 

Alternative (Section 4.17.4.1) would continue. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.17.5 Oil, Gas and Utilities Pipelines 

4.17.5.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on oil, gas, and utilities pipelines. Indirect impacts 

of not implementing wetland creation/nourishment and shoreline protection features would 

result in the persistence of existing conditions including the fragmentation and degradation of 

the Lake Borgne - MRGO land bridge. These conditions would expose buried pipelines thereby 

increasing the risk of failure or damage due to lack of structural stability, anchor dragging, and 

boat collisions. Cumulative impacts would be the synergistic effect of the No-Action 

Alternative on oil, gas, and utilities pipelines with the additive combination of similar oil, gas, 

and utilities pipeline impacts from wetland loss and degradation throughout coastal Louisiana, 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 65

as well as the benefits and impacts of other state and Federal projects in the vicinity, as detailed 

in Section 4.1.1 and Table 4.2. 

4.17.5.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): No direct impacts are anticipated as construction design and 

activities related to implementing shoreline protection and wetland creation and nourishment 

would avoid and minimize potential impacts to existing oil, gas and utilities pipelines. . 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.17.5.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Restoration features could potentially reduce some maintenance 

costs through increased protection of buried pipelines compared to the No-Action Alternative. 

Alternative 10 (SP) is designed to be constructed in a manner that would avoid the need to 

relocate any pipelines in the project area. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.17.5.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect with the 

additive combination of impacts and benefits for overall net acres created, nourished, and 

protected by other Federal, state, local, and private restoration efforts as summarized in 

Section 4.1.4 and Table 4.2. Alternative 10 (SP) would work synergistically with those 

projects to provide more complete protection for the land bridge, which would prevent the 

increase in maintenance and relocation costs for pipelines in and around the project area 

compared to the No-Action Alternative. 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.6 Commercial Fisheries 

4.17.6.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on commercial fisheries. Indirect impacts would 

result in the persistence of existing conditions including the continued conversion of existing 

wetlands to open water habitats, continued bankline erosion and sloughing of the shoreline. The 

Coast 2050 Report (LCWCRTF & WCRA, 1999) predicts that coastal wetland loss would 

impact most commercially important species, including black drum, brown and white shrimp, 

and blue crab, leading to declining abundances in the project area. 

Cumulative impacts would be the synergistic effect of the No-Action Alternative on commercial 

fisheries with the additive combination of coast wide fishery habitat losses and degradation, as 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 66

well as the benefits and impacts of other state and Federal projects in the vicinity, as detailed in 

Section 4.1.1. Sharp declines are predicted in fisheries productivity under the No-Action 

Alternative (USACE, 2004). Globally, overfishing and habitat change has resulted in the 

depletion of 90% of the world’s seafood resources, with 38% of the species studied 

experiencing greater than 90% depletion, and 7% becoming extinct (Worm et al., 2006). This 

trend is expected to continue under the No-Action Alternative. 

4.17.6.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Direct impacts would be localized, temporary and primarily related 

to construction activities that would make the areas in the immediate vicinity of the proposed 

action unavailable to conduct commercial fishing activities. Following completion of 

construction activities, those areas would become available for commercial fishery activities. 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.6.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of transitional emergent wetlands 

that would provide EFH that would support populations of fishery species and enhance 

commercial fishing opportunities (See Section 4.4, Fishery Resources). 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.17.6.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts of this alternative would affect relatively small 

percentage of active oyster leases located the near the project area, but would not significantly 

impact other fisheries. Cumulative impacts would be the synergistic effect with the additive 

combination of impacts and benefits for overall net acres created, nourished, and protected by 

other Federal, state, local, and private restoration efforts as summarized in Section 4.1.4. 

Alternative 10 (SP) would work cooperatively with those projects to provide more complete 

protection for the land bridge, which would provide important fisheries habitat. Overall, the 

industry would be more stable near the project area due to a long-term increase in the quality of 

fisheries habitat. Globally, overfishing and habitat change, which has resulted in the depletion 

of 90% of the world’s seafood resources (Worm et al., 2006), would be expected to continue 

with Alternative 10 (SP). 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 67

4.17.7 Oyster Leases 

4.17.7.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on oyster leases. Indirect impacts would result in 

the persistence of existing conditions including the continued conversion of existing transitional 

estuarine wetlands to open water habitats, as well as continued MRGO bankline erosion and 

sloughing of the Lake Borgne shoreline. The continued loss of transitional estuarine wetlands 

would adversely affect the local detritus-based oyster food web. Organic detritus, derived 

mainly from vascular plants, is a major food source for estuarine consumers, including oysters 

(Day et al., 1989). The loss of estuarine wetlands not only reduces detritus, which is used 

directly by oysters, but also reduces catabolic products (i.e., process by which complex 

substances are converted to more simple compounds) that are more often utilized by primary 

producers (e.g., phytoplankton), which can then be used by oysters and other species (Kilgen 

and Dugas, 1989). Oysters depend on estuarine wetlands for protection and food when they are 

juveniles (source: www.nmfs.noaa.gov/habitat/habitatconservation/publications/habitatconections/num4.htm). 

Hence, the loss of wetlands in the project area would likely alter the detritus-based food web of 

the oyster thereby reducing the localized carrying capacity for oyster leases in the area. 

Cumulative impacts would be the synergistic effect of not implementing shoreline protection 

and wetland creation and nourishment on oyster leases with the additive combination of coast 

wide oyster lease impacts due to wetland loss and degradation, as well as the benefits and 

impacts of other state and Federal projects in the vicinity, as detailed in Section 4.1.1 and

Table 4.2. The continued loss of transitional estuarine wetlands and the likely resultant decline 

in oyster production in and near the project area would likely result in a local reduction of 

oysters, which could lead to higher local oyster prices as leases farther from ports would be 

relied upon to maintain harvests. There could be similar impacts to nearby state oyster seed 

grounds in Lake Borgne. This could reduce the local availability of seed oysters used to sustain 

the local oyster lease productivity. The WRDA 2007 authorized diversion at or near Violet, 

Louisiana, would introduce up to 15,000 cfs (425 m3/sec) into the project area. Coupled with 

the closure structure on the MRGO channel at the Bayou La Loutre ridge, the Violet diversion 

would freshen the surrounding waters, albeit to an unknown extent. This could result in slight 

shifts in oyster productivity by altering isohalines in and near the project area. 

4.17.7.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Table 4.4 displays the seven oyster leases that would be directly 

impacted by implementing Alternative 10 (SP). Direct impacts to these oyster leases would be 

primarily associated with dredging for floatation access. Dredging-related impacts to oyster 

leases located within floatation access corridors would include increased turbidity, siltation, 

temperature and biological demand and decreased dissolved oxygen. These impacts would be 

temporary and the area would return to ambient conditions following completion of dredging 

and construction activities. Any oysters within the floatation access corridors would suffer 

disturbance and/or mortality. However, floatation access corridors, shoreline protection 

features, borrow sites and wetland creation/nourishment sites would be designed to avoid and 

minimize potential adverse impacts to oyster leases and nearby Louisiana State Oyster Seed 

Grounds. In addition, best construction management practices would be utilized. Wetland 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 68

creation/nourishment sites would be constructed using containment dikes and silt curtains to 

prevent dredged slurry runoff, turbidity, and other construction-related impacts to nearby oyster 

leases and the Louisiana State Oyster Seed Grounds. Oyster leases expected to be adversely 

impacted by the project would be acquired from the leaseholder through the LDNR’s oyster 

acquisition program. Payments would be made for just compensation in accordance with 

Louisiana and Federal Law. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

Table 4.4 Oyster leases potentially impacted by implementing alternatives. 

Location Lease # Owner # Acres Expiration 

Lake Borgne 2760300 886 547.0 01/01/15 

Lake Borgne 2884107 2452 240.0 01/01/22 

Lake Borgne 2816801 689 108.0 01/01/16 

Lake Borgne 2817801 1258 22.0 01/01/16 

Lake Borgne 2835101 3057 287.0 01/01/11 

Lake Borgne 2818401 71 260.0 01/01/11 

Fort Bayou 3296107 2264 11.0 01/01/22 

4.17.7.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (876 ha) of transitional emergent wetlands 

that would provide protection and food for juvenile oysters 

(source: www.nmfs.noaa.gov/habitat/habitatconservation/publications/habitatconections/num4.htm); increase 

nutrients and detritus, a major food source for oysters and other major estuarine consumers 

(Day et al., 1989); increase the productivity of planktonic resources upon which oysters feed; as 

well as increase the availability of catabolic products utilized by primary producers which can 

then be used by oysters and other species (Kilgen and Dugas, 1989). Hence, the protection, 

creation and nourishment of wetlands in the project area would likely benefit the detritus-based 

food web of the oyster thereby increasing the local carrying capacity and yields for oyster 

leases. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP) except 

Alternative 2 would protect, create and nourish a net total of 2,264 acres (917 ha). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP) except 

Alternative 3 would protect, create and nourish a net total of 2,284 acres (925 ha). 

4.17.7.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts would be the synergistic effect of 

implementing Alternative 10 (SP) with the additive combination of impacts and benefits for 

overall net acres created, nourished, and protected by other Federal, state, local, and private 

restoration efforts as summarized in Section 4.1.4 and Table 4.2. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 69

The diversion authorized by WRDA 2007 at or near Violet, Louisiana, would introduce up to 

15,000 cfs (425 m3

/sec) into the project area. Coupled with the closure structure on the MRGO 

channel at the Bayou La Loutre ridge, this feature would freshen the surrounding waters, albeit 

to an unknown extent. This could result in slight shifts in oyster productivity by altering 

isohalines in and near the project area. Alternative 10 (SP) would work synergistically with 

those projects to provide more complete protection for the land bridge, which would provide 

protection to some oyster leases in the vicinity of the project area. 

Creation, protection and nourishment of emergent wetlands in the project area in conjunction 

with other actions proposed and implemented in the vicinity would increase the productivity of 

planktonic resources upon which oysters feed. 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.8 Flood Control and Hurricane Protection Levees 

4.17.8.1 The No-Action Alternative 

The No Action Alternative, not implementing shoreline protection and wetland creation and 

nourishment, would have no direct impacts on flood control or hurricane protection levees. 

Indirect impacts would result in the persistence of existing conditions including the continued 

degradation of the land bridge separating Lake Borgne from the MRGO channel, the conversion 

of existing wetlands to open water habitats, and the continued bankline erosion and sloughing of 

the shoreline. Cumulative impacts would be the synergistic effect of the No-Action Alternative 

on flood control and hurricane protection levees with the additive combination of coast wide 

impacts to flood control and hurricane protection levees due to wetland loss and degradation, as 

well as the benefits and impacts of other state and Federal projects in the vicinity, as detailed in 

Section 4.1.1 and Table 4.2. 

Based upon recent sensitivity studies conduced by ERDC in support of the LACPR evaluation 

of comprehensive hurricane protection analysis and designs, the loss of wetland areas increases 

storm surge and wave potential at the hurricane protection system. These increases are 

amplified in areas where the levees have irregular shapes and form “pockets” or “funnels” 

(personal communication, Mr. Ty Wamsley, ERDC, April 24, 2007). However, because the 

acreage of wetlands lost, levee heights and alignments, shoreward depths and storm 

characteristics all affect the height of storm surge, it is difficult to determine at this stage of 

scientific knowledge the effect of wetland loss in the area around Lake Borgne on storm surge 

(personal communication, Mr. Van Stutts and Ms. Janice Hote, LACPR Hydrology Team, 

December 19, 2007; see Section 4.9 Hydrology). Consequently, degradation of the land bridge 

could expose existing flood control infrastructure, including the authorized flood control 

structure for the GNOHSDRRS located in the western portion of the Golden Triangle, more 

directly to the wave climate of Lake Borgne, potentially resulting in higher erosion rates and 

increased maintenance needs. 

4.17.8.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Wetland creation and shoreline protection would have no direct 

impact on flood control or hurricane protection structures. 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 70

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 

4.17.8.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Over the 50-year period of analysis Alternative 10 (SP) would 

protect, create and nourish a net total of 2,162 acres (874 ha) of emergent wetlands that would 

maintain the Lake Borgne - MRGO land bridge. However, increasing the acreage of wetlands 

in the proposed action area (landbridge between Lake Borgne and the MRGO) would not 

significantly reduce storm surge or wave heights in this area (personal communication, Mr.Ty 

Wamsley, ERDC, April 24, 2007). Rather, protecting wetlands (preventing their loss) would 

have a net effect of lowering storm surge and wave heights, to some undetermined compared to 

the No Action Alternative future condition with extensive wetland loss. Although a significant 

increase in wetland acreage in the area could have an effect on significantly reducing storm 

surge and wave heights, the acreage required to accomplish this has not been quantified 

(personal communication, Mr. Van Stutts and Ms. Janice Hote, LACPR Hydrology Team, 

December 19, 2007). 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.17.8.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Cumulative impacts to flood control and hurricane protection 

structures would primarily be associated with incremental impacts of similar wetland and 

protection features. Cumulative impacts would be the synergistic effect with the additive 

combination of impacts and benefits for overall net acres created, nourished, and protected by 

other Federal, state, local, and private restoration efforts as summarized in Section 4.1.4. 

Alternative 10 (SP) would work cooperatively with those projects to provide more complete 

protection for the land bridge, which would continue to provide the current level of storm surge 

reduction in the project area and vicinity. 

The land bridge between Lake Borgne and the MRGO channel would continue to fragment and 

degrade albeit to a lesser degree with implementation of the following shoreline protection 

projects: 

y CWPPRA PO 30; 

y the MRGO 2006 Lake Borgne Shoreline Protection, (Doulluts Canal to Jahncke’s 

Ditch), St. Bernard Parish, LA (06-C-0210) project; and 

y the MRGO 2007 North Bank Foreshore Dike Construction and Repairs, Mile 44.4 to 

Mile 39.9 (Non-Continuous), St. Bernard Parish, LA (07-C-0089). 

ALTERNATIVE 2: Impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Impacts would be similar to Alternative 10 (SP). 
Chapter 4 Environmental Consequences 

FEIS June 2009 

 4 – 71

4.18 HAZARDOUS, TOXIC, AND RADIOLOGICAL WASTE 

(HTRW) 

4.18.1 The No-Action Alternative 

The condition with the No-Action Alternative regarding the potential for HTRW is dependent 

on site-specific HTRW discovery. Based on previous HTRW studies in the project action area, 

there is reason to believe that the potential to encounter HTRW problems would be low. 

4.18.2 Future With Project Conditions – Direct Impacts 

ALTERNATIVE 10 (SP): Consistent with ER 1165-2-132, an HTRW investigation of the 

project area was conducted. Based upon findings from this investigation, the potential for direct 

impacts to the project area from implementation of the SP would be low and would likely 

continue to be low into the future. 

ALTERNATIVE 2: Direct impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Direct impacts would be similar to Alternative 10 (SP). 

4.18.3 Future With Project Conditions – Indirect Impacts 

ALTERNATIVE 10 (SP): Consistent with ER 1165-2-132, an HTRW investigation of the 

project area was conducted. Based upon findings from this investigation, the potential for 

indirect impacts to the project area from implementation of the SP would be low and would 

likely continue to be low into the future. 

ALTERNATIVE 2: Indirect impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Indirect impacts would be similar to Alternative 10 (SP). 

4.18.4 Future With Project Conditions – Cumulative Impacts 

ALTERNATIVE 10 (SP): Consistent with ER 1165-2-132, an HTRW investigation of the 

project area was conducted. Based upon findings from this investigation, the potential for 

cumulative impacts to the project area from implementation of the SP would be low and would 

likely continue to be low into the future. 

ALTERNATIVE 2: Cumulative impacts would be similar to Alternative 10 (SP). 

ALTERNATIVE 3: Cumulative impacts would be similar to Alternative 10 (SP).