Old River Control Structure of 1973 almost caused the control structure to fail. Integrity of the Old River Control Structure, the nearby Morganza Spillway, and other levees in the area is essential to prevent such a diversion. Jeff Masters of "Weather Underground" noted that failure of that complex "would be a serious blow to the U.S. economy." The present Old River Control Structure was completed in 1964 and expanded in 1990. The first two floodgates are the Low Sill Control Structure, which regulates routine flow in the waterway, and the Overbank Control Structure, in use only when the Mississippi exceeds its banks. A navigation
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