FACT SHEET: Chile’s Alto Maipo Hydroelectric Project (PHAM)

The Alto Maipo Hydroelectric Project (PHAM) is a large-scale run-of-the-river project in Chile with an installed capacity of 531 MW and an estimated annual output exceeding 2,100 GWh. Despite being pitched as a public good, the project faces significant opposition due to its potential to reduce the flow of the Yeso, Volcán, and Colorado Rivers by up to 60%, threatening drinking water for Santiago's 7 million residents and irrigation for 120,000 hectares of farmland. Financially, the project has seen costs rise to US$2.4 billion, with the Grupo Luksic consortium withdrawing in January 2017 at a loss of $350 million. The project is funded by several multilateral banks, including the IFC (US$150 million) and the IDB (US$200 million), both of which are facing complaints regarding violations of environmental and social policies. Environmental concerns include accelerated desertification, erosion of riverbeds, and risks to protected areas like the Glacial Natural Monument. The Chilean government has penalized the project for 14 separate violations of environmental norms.

• The PHAM is a run-of-the-river project with an installed capacity of 531 MW and an estimated annual output of over 2,100 GWh, but its construction has faced repeated delays and cost increases, with total costs now projected at US$2.4 billion.
• The project threatens critical water resources by diverting water from the Yeso, Volcán, and Colorado Rivers by up to 60%, which are primary sources of drinking water for Santiago's 7 million inhabitants and irrigation for 120,000 hectares of farmland.
• The project is linked to severe environmental risks, including the acceleration of desertification in northern and central Chile, significant riverbed erosion, and threats to protected areas such as the Glacial Natural Monument.
• Financial instability has marked the project, highlighted by the January 2017 withdrawal of the Luksic consortium at a loss of $350 million and a 30% drop in the stock value of AES Gener over a six-month period.
• The project has faced legal and regulatory challenges, including 14 penalties from the Chilean Environmental Superintendent for environmental norm violations and formal complaints filed with the IFC's Compliance Advisory Ombudsman and the IDB's Independent Consultation and Investigation Mechanism.

APA

Center for International Environmental Law (n.d.). FACT SHEET: Chile’s Alto Maipo Hydroelectric Project (PHAM). https://www.ciel.org/wp-content/uploads/2017/02/FactSheet_AltoMaipo_Chile.pdf

Chicago

Center for International Environmental Law. FACT SHEET: Chile’s Alto Maipo Hydroelectric Project (PHAM). n.d. https://www.ciel.org/wp-content/uploads/2017/02/FactSheet_AltoMaipo_Chile.pdf.

Wikipedia

{{cite report |author=Center for International Environmental Law |title=FACT SHEET: Chile’s Alto Maipo Hydroelectric Project (PHAM) |url=https://www.ciel.org/wp-content/uploads/2017/02/FactSheet_AltoMaipo_Chile.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{centerforinternationalenvironmentallawndfact, author = {{Center for International Environmental Law}}, title = {{FACT SHEET: Chile’s Alto Maipo Hydroelectric Project (PHAM)}}, institution = {Center for International Environmental Law}, url = {https://www.ciel.org/wp-content/uploads/2017/02/FactSheet_AltoMaipo_Chile.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }