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Title: Southwest Coastal Louisiana Study : Integrated Final Feasibility Report and Environmental Impact Statement
Authors: United States. Army. Corps of Engineers. Mississippi Valley Division.
Keywords: Flood control
Environmental management
Restoration ecology
Publisher: United States. Army. Corps of Engineers. New Orleans District.
Abstract: The Recommended Plan (RP) described in the Southwest Coastal Louisiana Integrated Final Feasibility Report and Environmental Impact Statement provides nonstructural hurricane and storm surge damage risk reduction and ecosystem restoration across 4,700 square miles in Calcasieu, Cameron, and Vermilion Parishes in southwest Louisiana. The National Economic Development (NED) RP, Modified Plan 8 – Nonstructural 0-25-Year Floodplain Plan, would implement nonstructural measures to reduce coastal storm surge damages to 3,462 residential structures, 342 commercial structures and public buildings, and 157 warehouses. This would be achieved by elevating residential structures, dry flood proofing non-residential structures, and constructing localized storm surge risk reduction measures around warehouses. Residential structures would be elevated to the base flood elevation predicted to occur in the year 2075. Non-residential structures would have flood proofing measures applied generally up to 3 feet above ground level. Localized storm surge risk reduction measures would be less than 6 feet in height. Any structure that requires raising more than 13 feet above ground level would be ineligible to participate due to engineering and risk related factors. Implementation of the NED RP would directly, indirectly, and cumulatively benefit socioeconomic resources such as population and housing, tax revenue and property values, and community cohesion. Participation in the NED RP is entirely voluntary. The NED RP is fully compliant with Executive Order 12898 and no environmental justice issues are expected. The expected equivalent annual net benefits are $167.4 million dollars, with $906.1 million in project first costs, and a benefit-to-cost ratio of 5.65:1. The Federal National Ecosystem Restoration (NER) RP, Plan CM-4 – Small Integrated Restoration, includes 49 ecosystem restoration measures that address land loss and ecosystem degradation and would stabilize the wetland perimeter geomorphology and is the least-cost, cost-effective, comprehensive ecosystem restoration plan. The Federal NER RP includes 9 marsh restoration measures restoring a net total of 7,900 acres of brackish and saline marsh with 2,700 Average Annual Habitat Units (AAHUs); 5 shoreline protection measures protecting a net total of 6,135 acres of marsh with 1,738 AAHUs; and 35 chenier reforestation measures that would plant cheniers with live oak and hackberry for a net total of 1,413 acres with 538 AAHUs. Overall, the Federal NER RP would reforest, protect, and restore a net total of 15,448 acres with a total of 4,976 AAHUs at a cost of $2.485 billion. This includes protecting 335 acres of designated critical wintering habitat for the threatened piping plover that is also utilized by the rufus subspecies of the threatened red knot; enhancing plant productivity; and reinforcing and protecting critical landscape features. Two marsh restoration features (124d - Marsh Restoration at Mud Lake and 3c1 - Beneficial Use of Dredged Material from the Calcasieu Ship Channel) are partially located on United State Fish and Wildlife Service refuge lands. These two features provide 1,492 acres and 611 AAHUs at a cost of $297 million. The U.S. Army Corps of Engineers recommends that USFWS seek authorization and appropriation to construct these projects as part of the overall Federal NER RP. The Corps NER RP presented for authorization is comprised of the remaining features which provide 13,950 acres and 4,365 AAHUs. The Calcasieu Ship Channel Salinity Control Structure and the Cameron-Creole Watershed Spillway are recommended as additional long-range studies at a cost of $6 million. The NER RP features comprise an integrated restoration plan that would have synergy with other ecosystem restoration projects and would facilitate hydrologic and geomorphic stability and resilience. Implementation of the NER RP would directly, indirectly, and cumulatively benefit chenier forests, brackish and saline marsh, essential fish habitat, wildlife, fisheries, the threatened piping plover and the rufus subspecies of the red knot, water quality, and recreation. The NER RP is fully compliant with EO 12898 and no environmental justice issues are expected. The Corps NER RP project first cost estimate is $2.188 billion. The estimated total project cost for the Corps NED RP and NER RP (excluding projects that will be authorized, funded, and implemented as USFWS rojects) is $3,094,276,000 at FY 2016 price levels.
Description: Integrated Final Feasibility Report and Environmental Impact Statement
Rights: Approved for Public Release; Distribution is Unlimited
Size: 215 pages / 8.576 Mb
Types of Materials: PDF/A
Appears in Collections:Environmental Documents

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