West Atchafalaya Floodway and west by the Atchafalaya Basin protection levees, and on the south by the Gulf of Mexico. Farther downstream, floodwaters enter the Gulf of Mexico through the Atchafalaya River below Morgan City, Louisiana and the Wax Lake Outlet. West Atchafalaya Floodway The West Atchafalaya Floodway is a flood control structure of the Mississippi River and Tributaries Project located in the Lower Atchafalaya Basin in south-central Louisiana. It has a project design flood flow capacity of . The Atchafalaya Basin system comprises three floodways. Two of these, the West Atchafalaya Floodway and the Morganza Floodway, are at the northern end. Together
Morganza Spillway 2011 event) had been opened by the Corps of Engineers. The Corps estimated the flow rate at . However, on May 25, new estimates from the U.S. Geologic Survey (USGS) described a much higher rate of , resulting in the closure of 3 bays by May 26, and additional closures by May 29, bringing the total to 11 bays with an estimated diversion rate of . The Corps continued to evaluate the flow and close additional bays as appropriate. By June 6, the number of open gates had been reduced to seven, and by June 8, only two gates were