Salinity Control in Mississippi River Under Drought Flows

Record low flow on the Mississippi River in 1988 created a potential for record prior movement of the saltwater wedge from the Gulf of Mexico, threatening water supply for the city of New Orleans and nearby communities. The U.S. Army Corps of Engineers employed one-dimensional and two-dimensional numerical models to design temporary underwater sill that would limit upstream salinity intrusion. The sill was constructed and successfully protected the freshwater supplies of the New Orleans area with cost savings of over $50,000,000. Postdrought analysis showed that the models accurately predicted behavior of the salt wedge and the sill.