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
67th Indiana Infantry Regiment 10-May 22. Advance from Franklin to Alexandria March 14–26. Battle of Sabine Cross Roads April 8. Monett's Ferry, Cane River Crossing, April 23. Constructing dam at Alexandria April 30-May 10. Retreat to Morganza May 13–20. At Morganza and Baton Rouge until August. Operations in Mobile Bay against Forts Gaines and Morgan August 2–23. Siege and surrender of Fort Gaines August 3–8. Capture of Fort Morgan August 23. Duty at Morganza until December. Expedition to mouth of White River November 12–20. The regiment lost a total of 249 men during service; 1 officer and 52 enlisted men killed or mortally wounded,