Old River Control Structure channel and lock were also part of the original facility design. Subsequent expansion created what is now known as the Old River Control Complex, when the Auxiliary Structure, which became operational in 1986, was added to reduce pressure on the original floodgates after extensive damage caused by the flood of 1973. The Sidney A. Murray Jr. Hydroelectric Station, completed in 1990, also provides an additional measure of control at the site. Water from the Mississippi is normally diverted into the Atchafalaya Basin only at Old River, where floodgates are routinely used to redirect the Mississippi's flow into the Atchafalaya River
120th Ohio Infantry May 1. Ordered to join Banks at Alexandria on Red River Expedition May 1. Embarked on steamer "City Belle". Action en route at Snaggy Point May 3. Over 200 men captured. Those who escaped were formed into a battalion of three companies and marched to Alexandria. Retreat from Alexandria to Morganza May 13–20. Mansura or Marksville Prairie May 16. Duty at Morganza until September. Expedition to mouth of White River and St. Charles September 13–20. Expedition to Duvall's Bluff, Ark., October 21–27. The regiment lost a total of 300 men during service; 2 officers and 17 enlisted men killed or