Mississippi flood of 1973 The Morganza Spillway was opened, flooding portions of the Atchafalaya River basin in Louisiana and causing the deaths of thousands of head of livestock and white-tailed deer. The 1973 flood was notable for nearly causing the failure of the Old River Control Structure above the Mississippi River Delta, which would have sent the Mississippi's main channel flowing into the Atchafalaya River and bypassing most of the delta region including the major port of New Orleans, Louisiana. In spite of record high flows, flood stages were not as high as past events. Red River Landing, Louisiana reached 58.22 feet on May
Morganza Spillway was expected in the Atchafalaya Basin regardless of the choice made regarding the Morganza Spillway, the Corps decided to start the 2011 diversion by opening the spillway a bit less than described in scenario 1a (21%, not 25%) The Governor of Louisiana, Bobby Jindal, had meanwhile sent a letter on May 4, 2011, to Robert Gates, the United States Secretary of Defense, requesting that the National Guard be deployed under Title 32 of the United States Code status to respond to record water levels in Louisiana, where there was "a significant probability that the U.S. Army Corps of Engineers [would]