Atchafalaya Basin 1973. This water floods the Atchafalaya Basin between the levees along the western and eastern limits of the Morganza and Atchafalaya basin floodways. The control of the river's floods, along with those of the Mississippi River, has become a controversial issue in recent decades. The US Geological Survey (USGS) reports that Mississippi River delta salt marshes are wetlands degrading at a rate of 29 square miles per year. The Atchafalaya River Deltas are the only locations of land growth along the Louisiana Gulf Coast. During the early 20th century, the Atchafalaya River Basin was designated as a spillway for floods
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