Morganza Spillway in 1954, the Morganza Spillway has been opened twice (in 1973 and 2011), and considered for opening during four other major floods of the Lower Mississippi River. On April 17, 1973, in order to lower the water level of the Mississippi River and relieve pressure on the Old River Control Structure, the Corps of Engineers opened 42 of the 125 steel gates of the Morganza Spillway for the first time since its completion, allowing about half of its maximum designed flowrate to pass from the Mississippi into the Atchafalaya Basin. The spillway received minor scouring and slight damage to the
Morganza to the Gulf Morganza to the Gulf The Morganza to the Gulf Hurricane Protection Project is a flood protection system for Terrebonne Parish and Lafourche Parish in the U.S. state of Louisiana. The targeted area is bounded on the west by Bayou Du Large and LA 311 (Louisiana State Highway 311) and on the east by Bayou Lafourche. The U.S. Army Corps of Engineers is the federal sponsor for this project, and the Louisiana Department of Transportation and Development with the Terrebonne Levee and Conservation District jointly serve as the local sponsor. The Terrebonne Levee and Conservation District will provide operations and maintenance