It is rarely used, but when the river is high, opening it eases pressure on the levees that protect New Orleans.
However it also carries pollutants and nutrients into the sound and reduces salinity. The result can be damage to oyster, fish and crab habitats, and algae blooms that affect marine life and beaches.
RECALL OF NEW ORLEANS MAYOR FAILS AFTER MAJORITY OF SIGNATURES RULED INVALID
Workers open bays of the Bonnet Carre Spillway to divert rising water from the Mississippi River to Lake Pontchartrain, upriver from New Orleans, in Norco, Louisiana, on May 10, 2019. (AP Photo/Gerald Herbert, File)
Coastal Mississippi governments and business interests sued the Corps over the openings in 2019, saying the it was legally required to consult with the National Marine Fisheries Service before opening the spillway. In January, U.S. District Judge Louis Guirola Jr. of Gulfport, Mississippi, agreed.
The Corps filed a notice of appeal Monday at the 5th U.S. Circuit Court of Appeals in New Orleans. Written arguments have not yet been filed.
Robert Wiygul, an attorney representing coastal Mississippi interests, said in January that the decision would not preclude the Corps from opening the spillway should high water levels threaten the city.
He said the judge’s order meant the Corps must discuss ways of mitigating the damage to fish habitat caused by opening the Bonnet Carre.