Atchafalaya Basin from the Mississippi, Red and Black rivers is diverted into the Atchafalaya at the Old River Control Structure. This flow diverts on average 25 percent of the Mississippi River flow down the Atchafalaya. In times of extreme flooding, the US Army Corps of Engineers may open the Morganza Spillway and other spillways to relieve pressure on levees and control structures along the Mississippi. On May 13, 2011, in the face of a rising Mississippi River that threatened to flood New Orleans and other heavily populated parts of Louisiana, the USACE ordered the Morganza Spillway opened for the first time since
3rd Missouri Regiment of Colored Infantry Gulf, to September 1864. 2nd Brigade, 1st Division, United States Colored Troops, District of Morganza, Dept. of the Gulf, to February 1865. 1st Brigade, 1st Division, United States Colored Troops, District of Morganza, Dept. of the Gulf, to May 1865. Northern District of Louisiana, Dept. of the Gulf, to July 1865. Moved from Benton Barracks, Missouri, to Port Hudson, Louisiana, arriving March 19, 1864, and duty there till June. Moved to Morganza, Louisiana, and duty there till June 1865. Action at Mt. Pleasant Landing, Louisiana, May 15, 1864 (Detachment). Expedition from Morganza to Bayou Sara September 6–7, 1864. Moved to