Morganza Spillway Structure (ORCS), in use since 1963, where floodgates are routinely used to redirect the Mississippi's flow into the Atchafalaya River such that the volume of the two rivers is split 70%/30%, respectively, as measured at the latitude of Red River Landing. During the 1973 Mississippi flood, the ORCS was being damaged due to high flow rates, leading to the opening of the Morganza Spillway to help relieve this pressure. Subsequently, the nearby Old River Control Auxiliary Structure (ORCAS) was constructed, adding additional floodgates for use during major floods. The Morganza Spillway, about downriver from ORCS and ORCAS, is designed for
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