Jamanxim River Jamanxim River The Jamanxim River is a river of Pará state in north-central Brazil. Originating in the Serra do Cachimbo, it is a tributary of the Tapajós, into which it flows a few kilometers upstream from Itaituba. The river flows through the Tapajós-Xingu moist forests ecoregion. It flows through the Itaituba I National Forest, a sustainable use conservation area established in 1998. The river basin also contains part of the Rio Novo National Park, a conservation unit created in 2006. Its hydroelectric potential, along with that of the Tapajós, was assessed by Eletronorte (Centrais Elétricas do Norte do Brasil S.A.),
Xingu River extracting from the river most of what they need for food and water. The Brazilian government is building the Belo Monte Dam, which will be the world's third-largest hydroelectric dam, on the Lower Xingu. Construction of this dam is under legal challenge by environment and indigenous groups, who assert the dam would have negative environmental and social impacts along with reducing the flow by up to 80% along a stretch known as the Volta Grande ("Big Bend"). The river flow in this stretch is highly complex and includes major sections of rapids. More than 450 fish species have been documented