The U.S. Army Corps of Engineers has given the final go-ahead for a $2.3-billion sediment diversion project in the Barataria basin in Louisiana, near the Mississippi River, west bank.

According to the Louisiana Coastal Protection Authority, the the Mid-Barataria Sediment Diversion project will restore river sediment flows into the basin, which has one of the world's highest land-loss rates and was one of the coastal estuaries hardest hit by pollution from the 2010 Deepwater Horizon oil spill.

The Corps signed a record of decision for the project on Dec. 19 and granted permits necessary, including one required under Section 404 of the U.S. Clean Water Act. Construction is expected to begin in 2023, dependent on the status of the funding.

“The green light on this project moves us closer to finally implementing a critical component of the solution to our land loss crisis that science has pointed us to for decades – using the land-building power of the Mississippi River to sustainably build and maintain land,” said Chip Kline, authority chairman, in a statement. He said the approvals would be "making our approach to coastal restoration and protection efforts stronger, more effective and more innovative.”

The project will reestablish a connection between the river and the basin by transporting sediment, freshwater and nutrients into the latter. At peak capacity, up to 75,000 cu ft per second of freshwater and its sediment and nutrients would be transferred. The aim is to rebuild and sustain up to 26,000 acres of wetlands, which will provide increased protection to local communities from hurricane-related storm surges.

工作的项目,自2013年以来,是有点controversial. Local fishing and some wildlife groups say the infusion of freshwater will devastate the local Bottlenose dolphin population. The authority has said it will spend up to $20 million to protect dolphins in the estuary; the Corps’ permit requires the agency to develop plans for both marine mammal protection and wetland mitigation.

Many environmental groups, including the Environmental Defense Fund, support the project. Jim Tripp, a retired group lawyer who has worked on Louisiana coastal issues since the 1970s, said Corps flood control and navigation levees along the Mississippi have disrupted natural flows of sediment, salt and silt into the estuary that had existed for thousands of years.

“Combating land loss and restoring the delta building processes requires reestablishing the historic sediment distribution functions of the river,” he said, in a statement. “That is what the Mid-Barataria Basin Sediment Diversion, the first major sediment diversion, is designed to do. After decades of planning, we are on the cusp of creating a better future for coastal Louisiana.”

The authority has requested that oil spill settlement dollars fund the project. The Louisiana Trustees Implementation Group, state and federal agencies responsible for overseeing how the state portion of Deepwater Horizon oil spill settlement dollars are spent, is expected to publish a record of decision on project funding early in 2023.