Posted on September 21, 2022
An unprecedented project to fight land loss devastating Louisiana’s coast by diverting sediment and water from the Mississippi River into Barataria Basin took a major step toward definitive approval on Monday with the release of a final environmental assessment by the U.S. Army Corps of Engineers.
The Corps released the lengthy report on the $2 billion Mid-Barataria Sediment Diversion Project. It breaks down how the new flow of freshwater and sediment for as much as half the year into the basin will create more than 20 square miles of new land during its first 50 years of operation.
It also looks at how it will reduce potential flooding for New Orleans area west bank communities, slightly increase the potential for flooding for communities downstream and significantly affect fisheries, oysters and bottlenose dolphins by increasing freshwater levels in the basin.
State officials view the project as the most important among the state’s ongoing coastal Master Plan in reducing the effects of subsidence and sea level rise on land loss, while also recognizing its potential effects on fisheries and residents, which will be offset by $380 million in projects to mitigate damages.
“This is a monumental moment for the state and the state’s coastal program,” said Chip Kline, chairman of the state Coastal Protection and Restoration Authority. “It has been told to us by members of the Biden administration that this is the largest coastal restoration project in the country, and the largest of its type anywhere in the world.”
He said Monday’s release of the report put the state on the “two-yard line” when it comes to receiving the final go-ahead to move forward with the project. Permits from the Corps allowing construction, and by federal and state BP oil spill trustees on funding the project, could now come as soon as December.
Those approvals will be based on the conclusions in this final version of the study. It provides a highly detailed look at the environmental impacts of the project, ranging from its huge land-building potential to the challenges it poses to the commercial fishing industry in Barataria Basin.
It follows up on a draft environmental impact report issued last year and addresses more than 40,000 public comments.
The project has been decades in the making and the state views it as having game-changing potential when it comes to the fight against coastal land loss. It would essentially mimic the processes that created southern Louisiana in the first place, sending millions of tons of sediment into the basin each year through the diversion.
Louisiana has lost land roughly equivalent to the size of Delaware since the 1930s. It could lose two more Delawares in the next half-century if no action is taken to stop it.
Louisiana’s land-loss crisis is due in large part to the levees that keep the Mississippi River on its current path and protect the communities surrounding it from flooding. What is now Louisiana was built slowly over eons by sediment deposited by the shifting river, which no longer occurs because of the levees, resulting in the interior land sinking as water and air are released over time.
At the same time, land-loss has been worsened by other manmade factors, including the canals cut through the marsh by the oil-and-gas industry and sea-level rise exacerbated by climate change.
Water levels along Louisiana’s coast could potentially increase by more than 4 feet by the end of the century. Climate change is also helping intensify hurricanes, which take a toll on coastal land as well.
The $2 billion project would be paid for with money from settlements related to the 2010 BP Deepwater Horizon oil spill. The plan includes projects to mitigate the impact of the diversion on the commercial fishing industry and nearby communities that could see increased flooding risks as a result.
Beyond concerns from commercial fishermen, another issue that has been controversial involves the impact on bottlenose dolphins. The project is expected to have a catastrophic effect on their numbers.
The project would introduce 5 to 7 million tons of sediment into Barataria Basin annually. It is expected to create more than 6,200 acres of land in its first decade.
When the effects of continued subsidence and sea-level rise are taken into effect, net land created is projected to be around 13,400 acres by 2070, the Corps study says.