Morganza, Louisiana mammoth work began in 1939 and was completed in 1955. High water of the Mississippi is channeled between guide levees north and west of the town of Morganza and down into the Atchafalaya Basin, thence to the Gulf of Mexico. The floodgates of this facility have been used only twice—during the high water of 1973 and 2011. Morganza is located at (30.735681, -91.593390). According to the United States Census Bureau, the village has a total area of , of which is land and (15.11%) is water. Climate is characterized by relatively high temperatures and evenly distributed precipitation throughout the year.
2011 Mississippi River floods to open more gates on the spillway, the Corps studied four flooding scenarios, all of which assumed the Bonnet Carré Spillway near New Orleans would be concurrently operating at full capacity (100%). Following this analysis, which showed that extensive flooding 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 Corps of Engineers subsequently released a map showing the estimated times it would take the flood waters to reach the various