Lerma River, a waterway in west-central Mexico. Beginning in the Toluca basin, in the state of Mexico, the river drops sharply into the basin of Guanajuato, winds through the fertile agricultural basin known as the Bajío, and empties into Lake Chapala in Jalisco, 350 miles away. From Chapala, the river continues as the Río Grande de Santiago, which flows through the agricultural lands of Jalisco before plunging over the western edge of the central plateau toward the Pacific. Collectively, the Lerma-Chapala-Santiago system forms the largest river basin located wholly within the borders of the Republic of Mexico.
Since the Lerma is one of the largest perennial waterways serving the densely populated southern portion of the central plateau, it is used extensively for drinking water, irrigation, and hydroelectric power. Water diversion from the Lerma began during the colonial period, to irrigate the important wheat- and cornfields of the Bajío, the breadbasket of Mexico. Much of the river is also diverted by aqueduct to meet the growing water needs of Mexico City.
Throughout the twentieth century, human and natural stresses on the Lerma have deteriorated its water quality and flow. Such problems are exemplified by the receding shores of Lake Chapala.
David Barkin and Timothy King, Regional Economic Development: The River Basin Approach in Mexico (1970), pp. 68-69, 113-115.
Jorge L. Tamayo, Geografía moderna de México, 9th ed. (1980), pp. 239-275.
Michael E. Murphy, Irrigation in the Bajío Region of Colonial Mexico (1986), esp. pp. 1-8.
Fabián Ruiz, José. Lerma y Balsas, crónica de dos ríos. Morelia, México: Foro Cultural Morelos, 1998.
Faugére-Kalfon, Brigitte. Entre Zacapu y Río Lerma: Culturas en una zona fronteriza. México: Centre Français d'Études Mexicaines et Centraméricaines, 1996.
Marie D. Price