Gulf of Mexico

LA - Less water to flow through Mid-Breton Sediment Diversion, Louisiana coastal officials say

$800 million coastal land-building project downsized from 47 to 31 square miles

Louisiana has revised its plans to move as much as 75,000 cubic feet of muddy water per second from the Mississippi River into Breton Sound, in order to keep the proposed $800 million Mid-Breton Sediment Diversion within budget and reduce the chance of flooding roads and fishing camps outside the levee. Instead, the project is being designed for a maximum 50,000 cfs.

“As we progress with these projects and start looking at their costs (and) benefits, we are right-sizing these projects to fit into the (coastal restoration) program,” Chip Kline, chairman of the state's Coastal Protection and Restoration Authority. “We’re not making these decisions in a vacuum.”

The proposed Mid-Breton Sediment Diversion on the east bank of Plaquemines Parish at Wills Point is being designed to move water and sediment from the Mississippi River into Breton Sound, to maintain existing wetlands and build new land.

The diversion would be built just south of Wills Point on the east bank of the Mississippi River in Plaquemines Parish in hopes it will add 31 square miles of new land in Breton Sound and bolster this part of Louisiana's fragile coast. It's about 30 percent designed, diversions program manager Brad Barth told the coastal authority's governing board on Wednesday.

The most recent update of the state’s Coastal Master Plan, in 2017, called for the diversion to have a maximum flow of 35,000 cfs. But in 2020, as part of the state's request to begin the federal permitting process for the diversion, it recommended a top flow be 75,000 cfs, the same as is proposed for the Mid-Barataria Sediment Diversion on the river’s west bank near Myrtle Grove. When first added to the master plan in 2012, the Mid-Breton diversion had a maximum flow of only 5,000 cfs.

The maximum flow would occur when the river’s flow upstream at Belle Chasse exceeds 1 million cfs. The diversion gates would not be opened at all until the river flow reaches 450,000 cfs.

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