Army Corps Begins Closing Bonnet Carre Spillway

Apr 13, 2020

The Army Corps of Engineers is closing the Bonnet Carre Spillway, 10 days after opening it to relieve pressure on the flooding Mississippi River.

Located in Norco, the flood control structure diverts water from the Mississippi River into Lake Pontchartrain, which prevents flooding and levee damage in the New Orleans area downstream.

The Corps opened it on April 3rd, as flood waters from the Midwest caused the river to rise. At the crest of flood water moved through the area, as much as 80,000 cubic feet per second rushed through the spillway’s diversion channel.

But with less water in the river’s forecast, Corps officials said it was time to begin slowly closing the structure, according to a press release. It has not yet said when the spillway will be completely shut.

In recent years the Corps has been under increasing pressure to minimize how long it keeps the spillway open.

Last year, the spillway was opened twice -- for more than 100 days. Agricultural fertilizers in the water caused toxic algal blooms as far away as Mississippi, shutting down public beaches. And the influx of fresh river water decimated fisheries, like oysters, which need salt water to survive.

Support for the Coastal Desk comes from the Greater New Orleans Foundation and the Walton Family Foundation.