Natural Resources Management in the Lerma-Chapala Basin

Abstract

This chapter describes the natural resources in the Lerma-Chapala watershed. The soil erosion is a problem that occur moderately in 45% of the Lerma-Chapala basin and in an accelerated way in 35% of the area. This is a consequence of the change in use of forest soil for agriculture, which generates the erosion of 25,000 ha per year and a sedimentary volume of 6 Mm₃, which are dragged off the reservoir. The most elevated area is located in the subvalley of Mexico State, where seasonal agriculture is practiced with low technology on highly inclined slopes, with limited vegetation, and deficient outlining of the terraces. To reduce erosion, several conservation programs have been applied, including filter dams, reforestation, stone barriers, high-density cultivation’s and surrounding terraces, among others. The environmental problem in the valley derives from strong water demand due to the accelerated socio-economical development of the region. Industrial and agricultural production overpasses the national average, and availabilities of water is exceeded by the demands in all the region. Extracting more surface or groundwater at any point of the valley, invariably affects the downstream water use as the continuous decrease of the Lake Chapala water level reflects as a result of the regulation of the water in the Lerma river. This situation endangers the social fairness, the environmental equilibrium, and the economic efficiency in the valley. Remedial actions are proposed to preserve water quality, organization and regulation of water use, and valley management and conservation that would contribute to the sustainability of the region.