Morganza Spillway - History

History

The Great Mississippi Flood of 1927 was the most destructive river flood in the history of the United States, in large part due to the Mississippi River swelling to 80 miles (130 km) wide in spots. To prevent a repeat of the Great Flood of 1927, and better control river flooding in general, Congress passed the Flood Control Act of 1928 to authorize the United States Army Corps of Engineers to build the Bonnet Carre Spillway (located 33 miles (53 km) above New Orleans and completed in 1931), the Birds Point floodway in Missouri, and the Morganza Floodway as part of the 1928 Mississippi River and Tributaries Project.

Construction of the levees that make up part of the Morganza Spillway began in the late 1930s. The Morganza Control Structure portion of the project was completed in 1954 and subsequently became incorporated into the Mississippi River Commission's 1956 project design flood, which added the Old River Control Structure (ORCS) in 1963 to the protections used to prevent Mississippi River flood. The Flood Control Act of 1965 provided further regulation over the Morganza Spillway's role in Mississippi River flood prevention. A concrete pit called a stilling basin was added at the Morganza Spillway in 1977 "to provide erosion protection after the velocity of water pouring through the open bays during a 1973 flood caused severe scouring of the land behind the bays."