Tietê River

Tietê River
Tietê River at Barra Bonita and Igaraçu do Tietê
Map of the La Plata Basin, showing the Tietê River flowing from São Paulo to the Paraná River.
Native nameRio Tietê (Portuguese)
Location
CountryBrazil
RegionSouth America
Physical characteristics
SourceSalesópolis, Serra do Mar
  elevation1,120 m (3,670 ft)
MouthLake at the Eng Souza Dias (Jupiá) Dam, Paraná River
  elevation
280.5 m (920 ft)
Length1,150 km (710 mi)
Basin size72,168 km2 (27,864 sq mi)
Discharge 
  locationNear mouth
  average(Period: 1971–2000)937.2 m3/s (33,100 cu ft/s)
Basin features
ProgressionParanáRío de la PlataAtlantic Ocean
River systemRío de la Plata

The Tietê River (Portuguese: Rio Tietê [tʃi.eˈte]) is a Brazilian river in the state of São Paulo.

The first known use of the name Tietê was on a map published in 1748 by d’Anville. The name means "truthful river", or "truthful waters”, in Tupi.

The Tietê River is a historically significant and economically important river, which stretches 450 kilometers and allows for navigation of barges carrying various goods.

Pollution of the Tietê River began subtly in the 1920s, but it has worsened significantly over time. In September 2010, National Geographic identified the river as the most polluted in Brazil. Despite efforts to clean up the river, it still suffers from pollution and environmental degradation, and some species are threatened, or possibly extinct.