Lake Chapala: The Largest Freshwater Lake in Mexico

Lake Chapala is the largest freshwater lake in Mexico, formed in one of the youngest geological formations of the American continent.

Lake Chapala Stats

Lake NameLake Chapala
Surface area1051.700
Maximum depth11.0
Average depth7.5
Lake typeNatural freshwater lake
Catchment area43691.90
InflowsLerma, Zula, Huaracha, Duero
Shore length221.32
Mixing typePolymictic
Residence time987.0
FrozenNever freezes
Trophic stateMesotrophic
Average discharge92.603

Lake Chapala Accommodation

Geography and Hydrology

Lake Chapala is located 45 kilometers South-East of Guadalajara, on the border of the Jalisco and Michoacan states. Three small islands are located on the lake: Isla de los Alacranes, Isla Mezcla and La Isla Menor.

The shallow lake’s main tributaries are Rio Lerma, Rio Zula, Rio Huaracha, and the Rio Duero. There are also plenty of season streams flowing into Lake Chapala. Its main outflow is the Rio Grande de Santiago, which flows north-west into the Pacific Ocean. The lake serves as a regulator to the climate of the area. There are a total of 11 major dams on the Lerma River, which were built to provide drinking water as well as water for industrial purposes and irrigation. 25% of the drinking water goes to Mexico City, the remaining belongs to Guadalajara.

Geology and Climate

Lake Chapala was formed in the Pleistocene, 38 000 years ago. During the Paleozoic era the lake was part of a fjord. When the Farallon plate was cleared in deriving Ribera, Nazca and Juan de Fuca, Chapala separated from the main fjord. It is now surrounded by volcanic cones.

The National Geographic Society named the local weather the “second best climate in the World”. The climate in the area is tempered, with rains occurring in the summer. The rainiest season is between the months of June and October. The coldest months are between December and February. The annual average temperature is 19.9OC.

Flora and Fauna

The lake surroundings serve as an important habitat for migratory birds, including the American White Pelican, many ducks, and migratory birds of the Atlantic. The area is also home to many indigenous plants and animals. 173 different species were recorded in 2011.

There are a total of 43 fish species, of which 39 are native and 4 are introduced fish. Hydrophilic trees such as the bald cypress and the willow, can be found in near river flows. The hills are mostly covered with oaks and pines.


The first settlements were built in pre-Hispanic times by travellers who arrived on the precinct from Aztlan. The inhabitants of Chapala were said to be Tecuexes, who were descendants of the Toltecs and were under the rule of Tonalan. In the 16th century the area was conquered by Alonso de Avalos, a Spanish-Italian condottiero, and became the property of the Viceroy and New Spain.

The first written descriptions of the lake can be found in the Miscellaneous Chronicle, which was written by Father Antonio Tello. It narrates the expedition of Nuno de Guzman and mentions the lake under the name “Mar Chapalico”, meaning “huge gap”. Alexander von Humboldt later described the lake’s main geographic facts in his work, the “Political Essay of the Kingdom of New Spain.

During the First World War, in 1915, Norwegian investors wanted to create a luxury resort at the lake, with complete plans of a railway with segregated carriages, complete with motor vessels, luxury hotels, automobile clubs and casinos. Even though the plans were solid, nothing was ever built.

Plenty of towns and cities surround the lake: Chapala, Ajijic, Jocotepec, San Antionio, San Juan Cosala and Tlayacapan. Unfortunately, these towns didn’t manage to develop evenly, since those who work in agriculture and tourism are generally wealthier, whilst the fishing villages remained poor.

Environmental Concerns

Lake Chapala has been the main water supplier to the city of Guadalajara since the 1950s. Shortly after conducting its waters towards the city, the lake witnessed a decrease in its water levels. This rebounded for a short period of time until 1979; when it faced a rapid dwindle due to the increase in human water consumption.

Deforestation didn’t aid the problem, since it led to erosion along the lake’s shores and its main tributary, the Lerma River. This increased the sedimentation in the lake, making it loose depth, increasing temperature and evaporation. The lake is polluted mainly by the Lerma River, which supplies it with municipal, agricultural and industrial waste. The accumulation of nutrients and the warming of the water have led to the spreading of the water hyacinth, an invasive plant species, which contributes to the shrinking of the lake because of its own water consumption needs.

These effects have had devastating consequences on the lake’s ecology, contributing to the decrease of fish stock, leading some fish species to the verge of extinction. The contaminated fish also represented a danger to the livelihood of the locals.

In 2004, Lake Chapala was named “Threatened Lake of the Year” by the Global Nature Fund. By 2008 water levels have risen, although they are yet to reach the lake level of 1979. By 2010 the water quality and level improved thanks to the water treatment plants that have been constructed along the Lerma River. The water has been officially approved for water consumption in 2008.

Tourism and Leisure

Tourism in the area was first established in the 19th century, with the first train trips that led from Ocotlan to Chapala. After president Porfirio Diaz paid a visit to a lake, tourism started to blossom. In the 1950s several developments around the lake further developed the increase in tourism.

Paddle boating, kayaking and kitesurfing are the most popular watersports activities on Lake Chapala. There are also plenty of cycling and hiking trails along the lake, and some designated areas for horseback riding. Getting around is very easy and cheap through the numerous taxis and bus lines.

In the last few decades the lake and its shores give home to one of the largest expat colonies. About 17,000 - 20,000 people (mostly from the United States and from Canada) come to Chapala after retirement, because of the great climate and the attractive scenery.

Lake Chapala Map