Atchafalaya Basin from the Mississippi, Red and Black rivers is diverted into the Atchafalaya at the Old River Control Structure. This flow diverts on average 25 percent of the Mississippi River flow down the Atchafalaya. In times of extreme flooding, the US Army Corps of Engineers may open the Morganza Spillway and other spillways to relieve pressure on levees and control structures along the Mississippi. On May 13, 2011, in the face of a rising Mississippi River that threatened to flood New Orleans and other heavily populated parts of Louisiana, the USACE ordered the Morganza Spillway opened for the first time since
Morganza to the Gulf to 4 in favor of the Water Resources Development Act, an enormous water projects bill containing the levee system. Congress has not passed a WRDA bill since 2000, and authorization for the Morganza project has stalled annually with it. Next WRDA will head to conference committee, where the House and the Senate will iron out any differences between their versions of the bill. Last year, WRDA died in the waning hours of the Senate stuck in conference committee. But Jerome Zeringue, executive director of the Terrebonne Levee and Conservation Board, said that the May passage of WRDA and a lack