Lake Chapala residents continue to enjoy the lake's relatively high water level. The amount of water hyacinth plants living in the lake appears to have been reduced recently by chemicals. Some say no adverse effects from the chemical use is expected - Steven Miller, July 4, 2006.

Lake Chapala is about 25 miles long from east to west with a maximum north-south width of about 20 kilometers (12.5 miles). Its large surface area (1,050 square kilometers or 405 square miles) makes it the largest natural lake in Mexico and the third largest in Latin America, after Lake Titicaca and Lake Nicaragua in Central America. Despite its size, Lake Chapala is quite shallow, with an average depth of only slightly over four meters (13 feet) and an maximum depth of less than 30 meters (9.75 feet) —Tony Burton

The region surrounding Lake Chapala comprises eight municipalities in the state of Jalisco and four in the state of Michoacan. Most of the area's visitors and residents from abroad gravitate to the north shore municipalities of Ajijic, Chapala and Jocotepec. —Dale Hoyt Palfrey

Lake Chapala is the largest natural lake in Mexico, located 42 km south of the metropolitan area of Guadalajara. Hydrologically it belongs to the Rio Lerma Lago de Chapala Rio Santiago drainage system, one of the most important in Mexico. The main tributary R. Lerma supplies almost half of the water input, while the R. Santiago drains the lake water to the Pacific Ocean.

This region, the Mesa Central Region, is a highly unstable geological zone. The lake forms part of an east west oriented graben which is a Tertiary lake system where the majority of once existed lakes are now dry or almost dry. The geological history of the lake is poorly known. It is thought that the present lake basin and the R. Santiago outflow originated in the middle Pleistocene or the late Pliocene. The original drainage was probably from the west end of the lake directly to the Pacific Ocean, but uplifting blocked that flow establishing the present R. Santiago drainage. Terraces provide evidence of lake water level variation due to climatic changes during the Pleistocene.