agricultural area comprising adjoining portions of western Coahuila and eastern Durango states, northern Mexico. The district, which contains approximately 312,000 acres (126,000 hectares) of irrigable land, was named for the shallow lagoons that were formed on the plains.

The land, once used only for grazing, belonged to a large hacienda until the 1850s. In 1936, under the agrarian reform program of Pres. Lázaro Cárdenas, it was divided among Indian communities into ejidos (ejido) (communal lands), and water from the Nazas and Aguanaval rivers was used for irrigation. Cotton production in the district increased dramatically for a number of years but declined sharply after severe drought in the early 1950s. Many farm families were relocated, and the government initiated new irrigation projects. The major cities of the area are Torreón and Gómez Palacio.