Iriri River Terra do Meio Ecological Station. The river varies greatly in volume depending on the season, and in the dry season include waterfalls, rocks and rapids. The Iriri River flows through the Tapajós-Xingu moist forests ecoregion. The river is rich in fish, including many species found only here and in the Xingu. Large sections remain unexplored due to its remoteness in a region surrounded by Amazon rainforest, and sections with strong current and cataracts. Iriri River The Iriri River () is a large tributary of the Xingu River in Brazil, in the state of Pará. It is long making it the
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