Corps Releases Draft EIS For Mississippi River Sediment Diversion, Seeks Comments

The New Orleans Engineer District has released a draft Environmental Impact Statement (EIS) for the proposed Mid-Barataria Sediment Diversion (MBSD), a $2 billion project that, if built, would connect freshwater, nutrients and sediment from the Lower Mississippi River to Louisiana’s Barataria Basin. The Corps prepared the draft EIS for the Louisiana Coastal Protection and Restoration Authority (CPRA) and the National Oceanic and Atmospheric Administration, lead trustees for the plan. The plan comes from the Louisiana Trustee Implementation Group and grows out of the 2016 Natural Resource Damages settlement following the 2010 Deepwater Horizon oil spill.

CPRA and NOAA, along with the Environmental Law Institute and Restore The Mississippi River Delta, will host community discussion groups March 22 and 23 and April 20 to look more closely at the project, which would divert up to 75,000 cubic feet per second of Mississippi River “freshwater and its sediment and nutrients” toward wetlands in the Barataria Basin. The meetings will be held virtually, with registration details available at www.gulfspillrestoration.noaa.gov.

The river intake for the diversion would be located just above the community of Ironton in Plaquemines Parish, on the west bank of the river, and just below the nearby ConocoPhillips Alliance Refinery. Water, nutrients and sediment would flow southwest to the Barataria Basin and, in theory, sustain or build wetlands on that side of the river.

Trustees believe, after 50 years in operation, with the diversion primarily flowing in winter and spring, “over 20 percent of the marsh in the Barataria Basin is projected to have been created or sustained by the diversion. The trustees believe that a sediment diversion is the only way to achieve a self-sustaining marsh ecosystem in the Barataria Basin.”

In its draft report, trustees pointed to expected benefits for wildlife like red drum, largemouth bass, blue crab, white shrimp, Gulf menhaden and migratory birds. Bolstering and building wetlands in the area would also have storm risk reduction benefits, with more land holding back storm surge from tropical systems.

The plan has its detractors, though, who point to wildlife damages from decreased salinity across the basin due to the influx of river water. Trustees admit to those negative impacts in the draft report on the MBSD.

“That reduction in salinity would negatively impact fish and wildlife species that rely on higher-saline waters and have moved further into the estuary as salinities have increased due to the severed connection between the river and the basin,” the report said. “Key species that would be affected include dolphins, brown shrimp and oysters.”

Supporters, though, see the project as the linchpin to the state’s coastal restoration efforts.

“Unless we act now, we risk losing it all,” said Steve Cochran, director of Restore The Mississippi River Delta. “The future of our entire region is at stake. The Mid-Barataria Sediment Diversion will build more wetlands than any other individual restoration project in the world, in an area experiencing some of the highest land loss rates on the planet. If our region is to have a fighting chance against land loss, hurricanes and sea level rise, we must put the muddy Mississippi back to work to rebuild our coast.”

Residents and interested parties have the ability to comment on the project now through May 4. The Corps also plans to host virtual public meetings April 6, 7 and 8. Registration details will be published about two weeks prior to the meeting.

Public comments may be posted online at https://parkplanning.nps.gov/MBSD or sent by mail to U.S. Army Corps of Engineers, New Orleans District, Attention: CEMVN-OD-SE, MVN-2012-2806-EOO, 7400 Leake Ave., New Orleans, LA 70118.

After the comment period for the draft EIS closes May 4, the next permitting milestone for the Mid-Barataria Sediment Diversion will come in March 2022, when the Corps expects to release the final EIS. A record of decision and final permit and authorization decisions could follow in April 2022.