The Grande de Santiago River is one of the longest rivers in Mexico, measuring up long. The river begins at Lake Chapala and continues roughly north-west through the Sierra Madre Occidental, receiving the Verde, Juchipila, Bolaños, and other tributaries. At La Yesca, the La Yesca Dam was completed in 2012 and the El Cajón Dam was completed downstream in 2007. Below El Cajón, the Aguamilpa Dam was completed in 1993, creating a reservoir covering a large part of the territory of the municipality of El Nayar in Nayarit. From Aguamilpa, the river descends to the coastal lowlands, passing by Santiago Ixcuintla and empties into the Pacific Ocean, northwest of San Blas, in Nayarit. The river is viewed by some sources as a continuation of the Lerma River, which flows into Lake Chapala. Mexico possesses a small percentage of the world's freshwater reserve, 0.1%. According to an article named Water use and its effects on the crater-lakes of Valle de Santiago, Mexico “most Mexican lakes are in an advanced state of desiccation or senescence, with volumes and surface area greatly reduced because of human activities”. Some examples of these damaging activities are wood cutting, inflow diversion for agriculture, groundwater over extraction, pollution and eutrophication. Together Rio Lerma Santiago is a little over 600 miles long, but alone Rio Santiago is reported to be 269 miles long. It is an extension of the Lerma River, which at 466 miles long it is one of Mexico's longest rivers. The water begins in the Mexican Plateau in Mexico City. Then travels westward and goes through the Lerma River, and empties in Lake Chapala, near Guadalajara. From there the water flows southward through Rio Santiago and dissipates to the Pacific Ocean near San Blas, in Nayarit. The river passes by Ocotlán, Poncitlán, Atequiza, Atotonilquillo, Juanacatlán, El Salto, Tonalá among other places.
Pollution
Less than fifty years ago the river was a place to fish, bathe, and swim. It is now a river full of pollutants. The Instituto Mexicano de Tecnología del Agua found over a thousand different chemicals in the main channel and its tributaries. These substances included semi-volatile and volatile organic compounds, such as phthalates, phenols, toluene, and carcinogenic flame retardants. This river is one of the most polluted in Mexico. In February 2008 an eight-year-old boy, Miguel Angel Lopez Rocha, died after he fell into the river. Rocha fell near the El Salto Falls. He died nineteen days later. His autopsy indicated heavy metal poison was the reason for his death. This brought attention to the severe contamination of the river. After this unfortunate incident the local community organized a group called "Un Salto de Vida", which sponsored the second National Assembly on Environmental Impacts held in El Salto in May 2009.
