Permit Suspended for Mid-Barataria Diversion

Following criticism from the Louisiana governor’s office, the New Orleans Engineer District has suspended its permit for the proposed $3 billion Mid-Barataria Sediment Diversion (MBSD), a project that was the central and most expensive part of the state’s coastal restoration plan.

Col. Cullen A. Jones, commander of the New Orleans District, informed the Louisiana Coastal Protection and Restoration Authority (CPRA) of the permit suspension in a letter to Gordon E. Dove, CPRA chairman, on April 25.

“This suspension is based on the state’s actions (including failures to act or to obtain compromise), its public statements and positions, new information and potentially changed circumstances since permit issuance,” Jones said.

When Louisiana Gov. Jeff Landry took office in January 2024, his administration began reviewing the project.

“[I]t became clear that a last minute out the door approval to proceed in construction of the MBSD was prematurely made by the prior administration,” Dove wrote to Jones on March 7, 2025, following a meeting with the governor’s office.

Lawsuits remained pending in both federal and state courts, local permits were not obtained, mitigation was not complete and engineering assessing the impact of a salt water wedge to the diversion was not performed prior to the start of construction, Dove said. The Corps constructed a sill, an underwater dike designed to block the upriver creeping of salt water due to low flow in the river, in 2023 and 2024 after increased salinity in the river threatened drinking water treatment plants in Plaquemines and St. Bernard parishes. Fresh drinking water had to be trucked to downriver communities in Plaquemines Parish. The Corps builds the sill at Mile 64.5 on the Mississippi River, near the intake for the proposed sediment diversion.

In Dove’s March 7 letter to Jones, he said the state also had discovered a report dated June 3, 2022, that contained hydraulic modeling for the diversion that differed from what was officially released for the project.

“[T]he report does not appear to have been disclosed to the public nor considered by all necessary persons within the Corps,” Dove wrote.

The missing FTN report differed from the basin-wide report, the Delft BW model, which the Corps relied upon for the project’s Environmental Impact Statement. The Delft BW model projected a net increase of land at 13,400 acres due to the diversion. The FTN models projected 4,700 to 8,000 acres. The Delft model projected more water flow and lower salinity, and it did not address the need to dredge or flush the diversion channel. The Delft model projected a constant base flow of 5,000 cfs (cubic feet per second), while FTN used a variable base flow of 0 to 5,000 cfs.

One of the state’s concerns was that, in later years of the project, silt building up in the diversion canal and outflow area would create back pressure and could require up to $50 million annually to maintain the intended flow. Additionally, modeling showed that flowing that much water into Barataria Bay would significantly lower the salinity levels in the bay.

The Mid Barataria Sediment Diversion was funded in large part by fines assessed to BP following the Deepwater Horizon blowout and spill in 2010. The state had already spent $500 million on the project, with construction moving ahead toward the end of former Gov. Jon Bel Edwards’ second term in office.

Jones’s letter cited negative impacts of the proposed diversion “such as, increased water levels and tidal flooding in communities within 10 miles to the north and 20 miles to the south of the diversion outfall, increased storm surge impacts, particularly on communities not protected by levees, greatly reduced abundance of brown shrimp and eastern oyster and cultural and economic losses that could cause, altered larval transport and recruitment patterns of some aquatic species and functional extinction of three of the four subpopulations of BBES bottlenose dolphins and sever reduction of the fourth subpopulation of BBES dolphin stock, an overall 97 percent reduction compared to No Action.”

Jones said any work pursuant to the Corps permit must stop, although contractors may complete their limited portion of the contract.

In backing up concerns about the effect of fresh water on wildlife, critics of the project have said more than 200 dolphins died when fresh water was diverted from the river through the Bonnet Carré Spillway into Lake Pontchartrain and Lake Borgne in 2019. Similarly, a levee breach at about Mile 42 on the east bank of the river has grown to 300 feet wide and more than 90 feet deep, with the influx of fresh water lowering salinity levels east of the river and destroying the oyster harvest in that area.