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Louisiana Coastal Area, Louisiana— Ecosystem Restoration Barrier Island Restoration, Marsh Creation, and River Diversio

Louisiana Coastal Area, Louisiana— Ecosystem Restoration Barrier Island Restoration, Marsh Creation, and River Diversion, Barataria Basin Feasibility Study. Importance of Coastal Louisiana to Nation.

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Louisiana Coastal Area, Louisiana— Ecosystem Restoration Barrier Island Restoration, Marsh Creation, and River Diversio

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  1. Louisiana Coastal Area,Louisiana—Ecosystem Restoration Barrier Island Restoration, Marsh Creation, and River Diversion, Barataria Basin Feasibility Study

  2. Importance of Coastal Louisiana to Nation • The Mississippi River is the lifeblood of coastal Louisiana’s industries, infrastructure, ecosystem, and culture • The Louisiana coastal area and the river greatly contribute to the Nation’s economic development • Billion dollar/yr coastal fishery industry • 30% of nation’s production • More than all of Atlantic seaboard production • More than any other Gulf state • Infrastructure for 17% of oil and 25% of natural gas produced in nation

  3. Importance of Coastal Louisiana to Nation • Navigation projects for No. 1 Port complex in Nation • 400 million tons/yr • 155 miles of waterways threatened by coastal erosion • Hurricane protection for 2 million people • Coastal habitat for millions of birds and animals • 70% of Nation’s migratory waterfowl of Mississippi Flyway overwinter in Louisiana coastal area • World renowned for recreation – fishing, hunting, and boating

  4. Importance of Coastal Louisiana to Nation • The entire Mississippi River drainage basin drains through south Louisiana • Strategic national location for the regulation of basin floodwaters using Old River Control Complex, locks, flood gates, and levee systems • Supports existence, economic growth, and prosperity of businesses located along the floodplains of the entire Mississippi River and its tributaries • With the Nation’s necessary continued use of river controls in south Louisiana, river water that is life giving to coastal areas is channeled directly to the Gulf of Mexico • This represents a continual loss of natural wetland sustenance

  5. Louisiana Land and Water Changes 1956-1990

  6. 1956 2050 ??? Will Be Lost Forever... 2050 projection adapted from LSU Natural Systems Engineering Laboratory, 1998

  7. LOUISIANA COASTAL PLAIN Land Loss 1930's to 1990* and 2050 Projection 6,000 1,000 square miles 1,500 square miles 5,500 5,000 Land Remaining (thousand of acres) 4,500 4,000 3,500 2050 1930 1956-58 1974 1983 1990 * after Dunbar et al. 1992

  8. Causes of Loss: 160 million tons of sediment are delivered to the continental shelf each year. Most of this material is unavailable for marsh building processes because levees prevent overbank sedimentation.

  9. Causes of Loss: (continued) Canal and Channel Dredging

  10. Causes of Loss: (continued) Herbivory

  11. Low 0-1 Intermediate 1.1 - 2 High 2.1 - 3.5 after Gagliano, 1999 Causes of Loss: (continued) Subsidence (ft/century)

  12. 20 Level Rise (Inches) 10 8 0 1990 2010 2030 2050 Year Causes of Loss: (continued) Relative Sea Level Rise after Wigley and Raper, 1992

  13. Will Be Lost Forever... By 2050 nearly 1,000 square miles of Louisiana’s wetlands, an area nearly the size of Rhode Island, will become open water.

  14. Will be lost forever...

  15. Impending Ecosystem Collapse • Funded projects will have addressed 22% of projected future marsh loss through 2050. • Even with these in place, 408,000 acres of marsh and 233,500 acres of swamp will be lost. • This will have major social, economic, and environmental consequences. At risk are: ~ Communities ~ Infrastructure ~ Fisheries ~ Migratory Birds ~ A Unique Culture • The Coast 2050/LCA Feasibility Study would address the remaining 641,500 acres of projected wetland loss.

  16. Available Options • Abandon the coast — relocate. • Put the coast on life support — rock, ring, and pump. • Status quo — small-scale solutions. • One comprehensive plan that addresses the causes of the problem — required to sustain our coast.

  17. Coast 2050:Toward a Sustainable Coastal Louisiana Vision: “…to sustain a coastal ecosystem that supports the environment, economy and culture of southern Louisiana, and that contributes greatly to the economy and well-being of the nation.”

  18. Coast 2050 Ecosystem Goals • Assure vertical accretion to achieve sustainability of greatest wetland acreage practicable • Maintain estuarine gradient to achieve habitat diversity • Maintain exchange and interface to achieve system linkages

  19. Acceptable to the Public Ecosystem Needs Federal State Local PARTNERSHIP Common Ground Consensus Building COAST 2050 Strategic Coastal Plan

  20. Results of Coast 2050 Initiative • Consensus-based, grass roots planning initiative for ecosystem restoration • Comprehensive plan for restoration of Louisiana’s coastal landscape by Federal, state, and parish governments • Identification of perceived and predicted problems facing coastal Louisiana • Broad-scale restoration strategies • Basis for Louisiana Coastal Area Feasibility Study

  21. ASCENSION ASSUMPTION CALCASIEU CAMERON JEFFERSON VERMILION IBERIA Coast 2050 Plan TERREBONNE LAFOURCHE TANGIPAHOA LIVINGSTON ST. TAMMANY ORLEANS Approved by all Coastal Parishes ST. MARY PLAQUEMINES ST. MARTIN ST. JOHN THE BAPTIST ST. JAMES ST. CHARLES ST. BERNARD The Consensus...

  22. LCA Feasibility Study • USACE Reconnaissance Report: • Supports the Coast 2050 Plan • Approved for feasibility study start in May 99 • LCA General Investigations study authorization • Used existing 1967 authority • Broad latitude for study purposes • Current purpose: ecosystem restoration • Project funding vehicle: Water Resources Development Act (WRDA)

  23. Barataria Basin Study Methodologyfor Ecosystem Restoration • No dollar-based benefit-cost ratio criteria • Primary Criteria: $/Habitat Unit • Additional Selection Criteria: Economic Impact • estimation of economic impact as ancillary benefits • hurricane, flood control, navigation • economic analysis qualified for intended use • Existing information updated • Ranges of costs stated • Cost Effectiveness/Incremental Cost Analysis used to optimize plans

  24. Louisiana’s Coast 2050 Regions: Coastal Louisiana Hydrologic Basin Area Louisiana’s Coastal Basins: LOUISIANA COASTAL AREA, LOUISIANA -- ECOSYSTEM RESTORATION REGION AND BASIN MAPS FOR LOUISIANA COASTAL AREA AUTHORITY U.S. ARMY ENGINEER DISTRICT, NEW ORLEANS, LA CORPS OF ENGINEERS August 1999

  25. Divert through Existing Locks Manage Outfall of Existing Diversions Enrich Existing Diversions with Sediment Restore Swamps Small River Diversions Manage Diversion Outfall Flood Protection Restore Natural Drainage Patterns Bayou Lafourche Protect Bay Fringe Marshes Interior Breakwaters Reef Zones Preserve Land Bridge River Diversions Maintain Shoreline Integrity Dedicated Dredging Sediment Trap for Marsh Creation Rebuild Little Lake Marshes Conveyance Channel and Delta Lobe LEGEND Build and Maintain Delta Splays Restore/Maintain Barrier Shoreline Improve Drainage Mississippi River Diversions with Outfall Management Marsh creation with dredged material Marsh Creation along Hwy 1 and Caminada Bay Extend Barrier Shoreline Prevent loss of sediments off of the Continental Shelf COAST 2050 REGION 2 REGIONAL ECOSYSTEM STRATEGIES

  26. Approach for Barataria Study 18-mo. interim report • Focus -- critical, fragile gulf perimeter: • Marsh creation • Barrier island restoration • River diversion • Objectives: • Rebuild and protect unique gulf fringe, bays, and shoreline ecosystem • Provide support to basin interior for restoration Preparation for envisioned 3-yr study during 18-mo. interim report: • Hydrologic and Hydraulic modeling developed for basin • Objective: • Prepare to evaluate interior basin strategies related to movement and circulation of water, sediment, and nutrients

  27. Land Loss 1930’S to 1956-58 1956-8 to 1974 1974 to 1983 1983 to 1990 Marsh Creation Barrier Island Restoration R2-17. Dedicated Delivery of Sediment for Marsh Building in Caminada Bay R2-16. Dedicated Dredging for Marsh Creation along Hwy. 1 R2-22. Restore/maintain Barrier Shoreline, Port Fourchon to Sandy Point LOUISIANA COASTAL AREA, LOUISIANA -- ECOSYSTEM RESTORATION Barrier Island Restoration, Marsh Creation, River Diversion, and Ecosystem Restoration, Barataria Basin MARSH CREATION, BARRIER ISLAND, & RIVER DIVERSION RESTORATION AREA MAP U.S. ARMY ENGINEER DISTRICT, NEW ORLEANS, LA CORPS OF ENGINEERS August 1999 R2-11. Delta Building Diversion at Bastian Bay

  28. Considerations for InvestigationMarsh Creation • Target areas (Hwy. 1 and Caminada Bay): • Alternatives for investigation: • Dredge and fill • Terracing • Vegetative Plantings • Three scales of analysis — each alternative

  29. Considerations for InvestigationMarsh Creation • Cut-to-fill volume of available material • Supply of dredging resources • Coordination with Gulf Region dredging events • Environmental impact to borrow areas • Slope stability of borrow areas, relocations • Potential dredge material sources: • Bayou Lafourche • Interior Barataria Basin lakes • Offshore

  30. Strategies to Meet Design Challenges:Marsh Creation • Research historical estuarine features of area. • Develop conceptual designs to emulate historically open water in areas. • Use combination of dredge-and-fill, terracing, and vegetative plantings. • Conserve available borrow resources.

  31. Considerations for InvestigationBarrier Island Restoration • Volume and characteristics of available material • Ship Shoal • Barataria basin ebb-tide shoals • Mississippi River • Types of dredging systems to efficiently and effectively perform work • Availability of dredging equipment • Coordination with regional dredging events • Environmental impact to borrow areas

  32. Considerations for InvestigationBarrier Island Restoration Adaptive Management Concept: • New sand in system thru dredge-and-fill • Sand will re-arrange itself over time – littoral drift • Some sand will be lost to gulf • Minimal Operation and Maintenance costs over project life (30-50 yrs)

  33. Strategies to Meet Design Challenges:Barrier Island Restoration —Port Fourchon to Sandy Point • Comprehensive offshore seismic and boring program • Wide swath gulfward of islands • Ship Shoal • Sediment suitability analysis • Three alternatives combining measures such as: • Dredge and place • Coastal structures (e.g., breakwaters, revetments, geotubes) • Three scales for each alternative

  34. Coast 2050 Strategy Delta Building Diversion at Bastian Bay

  35. WHAT IS THE COAST 2050 PARTNERSHIP ? Coast 2050 is about planning a better future for coastal Louisiana. The public and federal, state, and parish representatives have developed a single strategic plan to sustain our estuaries, using the best science available.

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