Louisiana Trustees Release Final Mid-Barataria Sediment Diversion Restoration Plan

Louisiana Restoration Area (September 21, 2022)  The Louisiana Trustee Implementation Group, the agencies charged with restoring Louisiana’s natural resources after the Deepwater Horizon oil spill, has released the Mid-Barataria Sediment Diversion Final Restoration Plan (PDF, 1,123 pages). The plan evaluates using a large-scale sediment diversion to reconnect the Mississippi River to Louisiana's Barataria Basin estuary to restore wetlands and contribute to the broader restoration of its ecosystem. If it is ultimately permitted and funded, this first-of-its-kind project, estimated to cost more than $2 billion, represents one of the largest and most innovative coastal habitat restoration efforts ever undertaken.

The project will re-establish historic delta processes by allowing for the controlled release of water, sediment, and nutrients from the Mississippi River into the Barataria Basin estuary, supporting ecosystem-scale restoration of the estuary.  

The sediment carried by the diversion is projected to restore over 13,000 acres of wetland habitat—which is 20 square miles, or the size of Breton National Wildlife Refuge. These restored wetlands would contribute to protecting communities and infrastructure, reducing impacts from storms, supporting healthier Gulf fisheries, and benefiting many species important to the region’s economy and environment. 

Restoration Plan Evaluation and Timeline  

In this Final Restoration Plan, the Louisiana Trustee Implementation Group evaluated six sediment diversion alternatives. In selecting the preferred alternative, the Trustees considered the benefits and impacts of each alternative, and reviewed extensive public input received on the Draft Restoration Plan, published in March 2021.   

The Trustees also participated in the U.S. Army Corps of Engineers’ environmental impact evaluation of the proposed sediment diversion project, which can be found on the Army Corps’ website. The Final Restoration Plan and Final Environmental Impact Statement will be considered by the Trustees to inform a final decision regarding implementation. That decision is anticipated to be made later this year. 

If implemented, project costs are anticipated to exceed $2 billion. Costs include funds for monitoring and evaluation, and a suite of stewardship and mitigation measures to offset adverse impacts where possible.  

Louisiana Coastal Protection and Restoration Authority (CPRA) and NOAA are the lead Trustees for this Final Restoration Plan, which was prepared jointly with the other Louisiana Restoration Area Trustees: the U.S. Department of the Interior, the U.S. Environmental Protection Agency, and the U.S. Department of Agriculture.  

Historic Context  

Louisiana’s wetlands act as critical foraging, nursery, and nesting grounds for hundreds of species of fish and other wildlife. The Deepwater Horizon oil spill was the largest in U.S. history, impacting the entire northern Gulf of Mexico ecosystem. The wetlands in the Barataria Basin estuary were the most heavily impacted.   

The oil spill and response accelerated an ongoing trend of coastal land loss, especially in the state’s Barataria Basin estuary. The species, fisheries, and communities that rely on estuarine habitats face serious challenges due to the continued loss of wetlands, increasing estuarine salinities, as well as sea level rise, and land subsidence.    

More Information and Plan Documents  

• Final Phase II Restoration Plan #3.2: Mid-Barataria Sediment Diversion Restoration Plan (PDF, 1,123 pages)  
• Executive Summary (English, PDF, 4 pages; Spanish, PDF, 5 pages; Vietnamese, PDF, 4 pages)  
• Mid-Barataria Sediment Diversion Fact Sheet (PDF, 3 pages)  
• U.S. Army Corps of Engineers Final Mid-Barataria Sediment Diversion Project Environmental Impact Statement