The Mississippi River Flood of 1973 1

The Mississippi River and Tributaries Flood Control Project (MR&T Project) is designed to control the “project flood,” which is the result of combining some of the most severe storms of record that have occurred in the valley and placing them in a pattern to produce the greatest flood having a reasonable probability of occurrence. The project flood would produce an estimated 3 million ft³/s flow at the latitude of Old River, half of which would pass down the leveed Mississippi River Channel to the gulf, the other half down the Atchafalaya Basin. The flood of 1973 was one of the great floods in the history of the Mississippi River. Without the MR&T Project, it is estimated that economic losses would have amounted to more than $15 billion instead of $1 billion. Without the project, an additional 14,500,000 acres of land would have been flooded.