Río Maipo, Metropolitan Region.

El Cajon del Maipo is located in central Chile, 50 kilometers southeast of the city of Santiago, in a mountainous area of the Andes. It is a valley made up of several villages on the banks of the Maipo River, the most populous being San José de Maipo. Altogether they total approximately 14,500 inhabitants. The identity and culture is governed by a combination of rural areas, with a large percentage of people who travel daily to work in the city of Santiago, with families dedicated to tourism and with sectors where the drovers maintain their traditions of moving their animals according to periods of wintering and summering that depend on the high mountain meadows and wetlands.

The primary industries of the Maipo basin provide environmental, residential and tourism services. The main environmental services provided by the basin are the supply of 80% of the potable water of the capital, delivery of irrigation to the 120,000 hectares in the agricultural valley of the region, allowing the rejuvenation of the soil and delivering the minerals of the high mountain range which give the seal of quality to agricultural products. It also receives 2 million tourists a year, being the “green lung” of Santiago and its main recreation site.

The Threat

The “Cajón” has been an over-exploited area since before the independence of Chile two hundred years ago. Among the activities that have had the greatest detrimental effect on the landscape are mining, livestock grazing, extraction of firewood and water, agriculture, energy and residential occupation. This combination of human activities has left the Cajón territory overexploited and vulnerable to extreme climatic phenomena and new largescale interventions have already provoked soil-related disasters associated with river floods and mass transport phenomenon with lethal consequences to human lives.


Laguna Lo Encañado, Laguna Negra, Embalse el Yeso.

To all this past abuse is added the threat of a mega hydroelectric project called Alto Maipo (PHAM), which alters and impacts 4 watersheds diverting the waters of the Volcán, Yeso and Colorado rivers (leaving flows less than 10%) to return to the river bed 100 km below, in the Maipo canyon. The project has been proposed by the transnational Aes-Gener and Antofagasta Mineral corporations of the Luksic group.

In addition to Alto Maipo, there are mega mining projects threatening the ecosystem and community health (Andina 244, Quempos and Escalones), and climate change, which has meant a 30% reduction in water resources over the last 10 years, intensifying the process of desertification.