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
Morganza, Louisiana on December 10, 2008: Morganza was the site of a Union Army encampment during the American Civil War. The largest battle in Pointe Coupee Parish was fought at nearby Stirling Plantation, on September 29, 1863. Sixteen Federal troops were killed, 45 were wounded, and 462 were taken prisoner. The Confederate losses included 26 dead, 85 wounded, and 10 missing. Although the Battle of Sterling Plantation was a Confederate victory, the Union troops burned the town of Morganza to the ground on October 1, 1863. Historian John D. Winters in "The Civil War in Louisiana" (1963) documents the arrival in May