Lake Atotonilco: A First Approach to Determining the Minimum Lake Level Necessary to Sustain Its Biodiversity

Lake Atotonilco is a shallow saline water body located in the central-west portion of Mexico. The lake is in the low plain of an endorheic watershed. It is shallow, with a large area of surrounding wetlands and serves as a refuge for dozens of native and migratory waterfowl. Its extremely flat morphometric features coupled with the precipitation and runoff regime from the watershed cause significant changes in the lake surface area and storage volume throughout the year. In recent years, the lake has behaved as an intermittent lake, remaining practically dry in June, and reaching its highest storage volume in October. An ecological water volume that the lake must maintain to support its biodiversity was estimated. This minimum lake storage volume can only be achieved if public policies are implemented to rationalize the use of water resources in the basin and to protect the few forest areas that remain in the watershed. Key Words: ecological minimum volume, endorheic watershed, lake bathymetry, playa lake.