The Mid-Barataria Sediment Diversion project is a component of the Coastal Louisiana restoration strategy that proposes to divert sediment-laden water from the Mississippi River to restore natural deltaic processes and increase land area in the Barataria Basin. Over a 50-year time frame, the project will build and maintain 10,000 to 30,000 acres of upland and freshwater and coastal marsh habitat and will restore and preserve critical coastal ecosystems damaged by the Deepwater Horizon oil spill. Confluence led the Endangered Species Act (ESA) and Essential Fish Habitat (EFH) consultations, assisted with the Oil Pollution Act (OPA) restoration plan, and contributed to National Environmental Policy Act (NEPA) review associated with the project.
Confluence managed the ESA biological assessment and EFH assessment to evaluate short-term construction effects as well as operational effects over the 50-year design plan for the project, located on the west side of the Mississippi River. The analytical approach deconstructed project activities to understand the potential impact mechanisms (e.g., turbidity, salinity change, etc.) as they relate to protected species’ preferences and tolerances as well as alterations to important habitats. This effort was conducted in close coordination with the Deepwater Horizon Oil Spill restoration plan for the project and a third-party environmental impact statement developed by the U.S. Army Corps of Engineers to ensure consistent analyses. Confluence guided the evaluation of projected impacts to ESA-listed species and EFH using habitat and species model outputs to project long-term operational effects of the project. These analyses focused on ESA-listed species including 5 species of sea turtle, 3 bird species, manatee, and pallid sturgeon, and EFH resources such as emergent marshes, submerged aquatic vegetation, soft bottoms, sand/shell, oyster reefs, and water column habitats.
The final environmental impact statement for this project was released September 19, 2022, putting the Mid-Barataria Sediment Diversion project one step closer to beginning construction in early 2023. Confluence is also assisting with the Mid-Breton Sediment Diversion project occurring on the east side of the Mississippi River. Louisiana’s Coastal Protection and Restoration Authority hopes that land/ marsh retention and growth resulting from sediment diversion projects such as these will provide communities with sustainability and protection from impacts of storm events and sea level rise, restore ecosystems, and boost local economies. With an estimated budget of up to $2 billion, the Mid-Barataria Sediment Diversion project is the largest sediment diversion project proposed to date and has attracted attention and scrutiny from regulatory agencies and the public. By using best available science and closely coordinating the NEPA and ESA processes with each other and with the OPA restoration plan, the ecological analyses have provided decision makers and the public detailed and accurate information on which to base their conclusions.
Plaquemines Parish, Louisiana
Louisiana Coastal Protection and Restoration Authority