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
69th Indiana Infantry Regiment until October. Western Louisiana "Teche" Campaign October 3-November 30. Ordered to Algiers December 13, then moved to Texas December 18. Duty at Matagorda Bay and Indianola until February 1864, and at Matagorda Island until April 19. Moved to New Orleans, thence to Alexandria, La., April 19–27. Red River Campaign April 27-May 22. Actions at Alexandria April 29 and May 2 to 9. Graham's Plantation May 5. Retreat to Morganza May 13–20. Duty at Morganza until December. Expedition to the Atchafalaya May 30-June 6. Expedition to mouth of White River and St. Charles, Ark., September 13–20. Moved to Dauphin Island, Mobile