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The Madeira River Basin – Amazon Under Threat

The Jirau rapids of the Madeira River are in threat of being dammed.
Credit: Glenn Switkes
See larger image

The Brazilian government is planning to build two massive dams on one of the Amazon’s most important tributaries, the Madeira River. The projects would threaten the river’s unique biodiversity, destroying habitat for fish, dolphins, parrots and a range of mammal species, and would affect the land and livelihoods of thousands of river bank dwellers and indigenous people.

Located in the state of Rondônia, the Madeira River is one of the principal tributaries of the Amazon, with its basin covering about one–quarter of the Brazilian Amazon. The river is rich in sediments it carries from the Andes. The region is also a treasure trove of biodiversity. The Madeira supports the life of an estimated 750 fish species, 800 bird species, and other endangered rainforest wildlife, and is home to rubber tappers, Brazil nut gatherers, and fishermen.

Two huge hydroelectric dams are planned – Santo Antonio (installed generating capacity 3,150 MW) and Jirau (installed capacity 3,300 MW)–at a total cost of US$9 billion. Construction of these projects–plus two additional dams upstream–would, according to the projects’ backers, open a 4,200 km industrial waterway for barge passage, permitting transport of soybeans, timber, and minerals to Atlantic and Pacific ports. The projects are the cornerstone of the Brazil–Bolivia–Peru hub of the Initiative for the Integration of South American Infrastructure, or IIRSA. The Brazilian government plans to offer the project to private investors in June or July, 2006, if it gets the OK from environmental licensing agencies.

The dams will seriously affect migratory fish and other aquatic species on the Madeira. Several species of large catfish migrate some 4,500 km each year to the upper Madeira to reproduce. Construction of the dams will block these migration routes, affecting the survival of the catfish. But it is not only aquatic species that are threatened. Thirty–three endangered mammal species are found in the region where the dams would be built. Among these are the Spotted Jaguar, Giant Anteater, Giant Armadillo, and Giant Otter. Their habitat is under threat. And ornithologists consider the Madeira region one of the world’s premier bird habitats. Among the unique features of the region to be flooded by the dam are barreiros, or exposed riverbanks, where hundreds of parrots flock to eat earth which is vital to their digestive process. Protected areas, including a reserve used by people who extract natural forest products, would be flooded by the dams.

Civil society organizations are organizing meetings in the region to alert the public to the threat the dams represent, and IRN and other organizations are carrying out independent technical studies regarding the project’s feasibility and analyzing its potential impacts.


Rio Madeira Vivo
Video produced by IRN’s Glenn Switkes. This version is in narrated in English.
The Amazon Under Threat: Damming the Madeira
IRN factsheet on campaign to stop hydroelectric dams on the Madeira.

latest additions

Brazil Gives Amazon Dams Go-Ahead
Read the BBC report on the granting of a provisional license for the Madeira River dams, July 10, 2007.
Brazilian Government Moves to Dam Principal Amazon Tributary
Article by Glenn Switkes on political pressure for approval of dams on the Madeira River, June 12, 2007.
Studies That Don’t Hold Water
IRN and FOE Amazonia summary of 30 issues raised by independent experts attesting to the inadequacy of environmental impact studies for the Madeira River Hydroelectric Complex, January 2007.
Independent Experts Find Fatal Flaws in Amazon Dam Studies
A group of independent experts -- including internationally-renowned authorities on the Amazon -- have found serious errors and omissions in the environmental impact assessment (EIA) for Brazil’s massive Madeira River hydroelectric project. The experts found the EIA to be inadequate, and recommend that additional studies be undertaken to evaluate the project’s impacts, November 13, 2006.
Additional Information

Glenn Switkes, Latin America Campaigns Director

International Rivers Network


Phone: +55 11 3822 4157