Rio Lerma: A Dying River
Rio Lerma, or the Lerma-Chapala-Santiago, located in Central Mexico is considered the largest and most important watershed in the country
Haciendas were built along this river during the 17th and 18th centuries, but today, it is now dotted with large cities, small cities, ranchos, and pueblos. Lake Chapala, where the Lerma flows into, is Guadalajara's main source of drinking water. This city's population alone is about 3.5 million people, while the entire watershed's population ranges to more than 15 million, making it one of the most committed basins in the world.
Rio Lerma is approximately 750 km-long; it begins at the Mexican Plateau, flows to form the border between the states of Querétaro and Michoacán before flowing to the states of Guanajuato and Jalisco. It ends when it empties into Lake Chapala; however, the Santiago River which empties out from Chapala for another 400 km toward the Pacific Ocean is considered to be the continuation of the Lerma. Therefore, the entirety of the watershed is often deemed as the Lerma-Chapala-Santiago river basin. The Laja, Apaseo, and Turbio are major tributaries to the Lerma.
Monthly streamflow data (Q in cubic meters per second) gathered from one of the Santiago's gauges, El Capomal city.
Annual statics retrieved from the monthly streamflow data (Q in cubic meters per second) gathered from one of the Santiago's gauges, El Capomal city.
Seasonal variability retrieved from the monthly streamflow data (Q in cubic meters per second) gathered from one of the Santiago's gauges, El Capomal city.
- Rio Lerma is deemed as "biologically dead" and environmentalists have described it as disgusting and definitely requires an unparalleled effort to fix. As mentioned before, most of the Lerma's upper basin area is heavily industrialized and chemical runoff and waste have contributed massively to the pollution and biological disturbances the river faces. More than 425 million cubic meters of both industrial and domestic waste are dumped into the upper basin area alone.
- Due to the pollution in the Lerma, certain species of the most populated fish that reside in the river have gone extinct. Strategies recommended to conserve Mexican Goodeids are to protect the best quality areas of habitat and to restore waters with lots of degradation. Labels have been applied to the remaining number of Goodeids; these include extinct, endangered, threatened, and under special protection.
The Lerma cannot be navigated, but it is very important to regional agricultural irrigation. It feeds thousands of farms and nearly a million hectares of farmland. There has been an increase in competition for groundwater, which has led to the decline of aquifer levels. Runoff has declined upstream due to consumptive uses and water demands are increasing for all sectors including domestic, industrial, and agricultural. Scarcity of water is not being caused by over usage, but rather because of the pollutants that have been introduced to the river; these organic and inorganic pollutants coupled with the lack of water treatment are what's causing the reduced water availability.
- Conclusion
The Mexican government has to take stronger steps toward more efficient water management, and contamination and environmental polices before massive environmental, social, economic, and political problems arise. The Lerma-Chapala-Santiago river basin houses over 15 million people, and these people cannot be displaced due to lack of governmental action.
