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 designed for a capacity of 531 MW. Despite its framing as a public good, it faces intense opposition from local communities and environmental organizations due to severe impacts on water resources, human rights concerns, and alleged violations of environmental and social standards by its financiers, including the IFC and IDB.

• The Alto Maipo Hydropower Project (PHAM) is a run-of-the-river (ROR) project with an installed capacity of 531 MW and an estimated annual output exceeding 2,100 GWh. The project involves diverting water from three main tributaries of the Maipo River for over 100 kilometers, including 67km of tunnels through the Andes Mountains. Construction costs have risen to a projected US$2.4 billion, which is more than four times the original estimate.
• The project is estimated to reduce the flow of the Yeso, Volcán, and Colorado Rivers by up to 60%. These rivers are critical as they provide drinking water for Santiago's 7 million residents and irrigate more than 120,000 hectares of farmland. Opponents argue the project will accelerate desertification in Chile's northern and central regions and cause significant riverbed erosion affecting public and private infrastructure.
• The PHAM has been funded by nine banks, including a US$150 million loan from the IFC and US$200 million from the Inter-American Development Bank (IDB), alongside investments from the US Overseas Private Investment Corporation, DNB ASA (Norway), and KfW IPEX-Bank (Germany). In January 2017, the Luksic consortium withdrew from the project at a loss of $350 million, leading the Austrian company Strabag to purchase a 7% ownership stake.
• The project faces significant legal and social challenges, including complaints filed with the IFC’s Compliance Advisory Ombudsman (CAO) and the IDB’s Independent Consultation and Investigation Mechanism (MICI) alleging violations of environmental and social policies. The Chilean government has penalized the company for 14 separate violations of environmental norms, and the Chilean National Institution of Human Rights has stated the project risks rights to water and a healthy environment.

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} }