2011 Mississippi River floods During the 2011 floods, the Army Corps of Engineers decided to open the Morganza Spillway at 1/4 of its capacity to allow to enter the Morganza and Atchafalaya floodways. In addition to reducing the 2011 flood crest downstream, this reduced the chances of a channel change by reducing stress on the other elements of the control system. 2011 Mississippi River floods The Mississippi River floods in April and May 2011 were among the largest and most damaging recorded along the U.S. waterway in the past century, comparable in extent to the major floods of 1927 and 1993. In April 2011,
Mississippi River Basin Model 1937, 1943, 1945 and 1952 were reproduced, as well as hypothetical floods at different periods of the year. Tests on individual problems were conducted until 1971 but high costs and growth of computer modelling meant that the facility was put on standby. The last use was in 1973, when a potentially catastrophic failure arose at the Old River Control Structure. The model was used to show that the untested Morganza Spillway could be opened effectively, without diverting polluted water through New Orleans and Baton Rouge, as well as identifying levees that required topping up. In 1993 the site was taken