Marañón

Marañón River is the primary or mainstem source of the Amazon River, rising about 160 kilometers northeast of Lima, Peru, and flowing northwesterly through a deeply eroded Andean valley, along the eastern base of the Cordillera de los Andes, until it reaches the Pongo de Manseriche, where it flows into the flat Amazon basin. Although the term "Marañon River" was once used to refer to the river all the way to the Atlantic Ocean, most cartographers today consider the Maraon River to cease at the confluence with the Ucayali River, after which the resulting waterway is known as the Amazon River.

The Marañón River is expected to supply 20 hydroelectric megadams planned in the Andes, with the majority of the power expected to be exported to Brazil, Chile, or Ecuador. Dam survey crews have developed construction designs, and environmental impact statements for the Veracruz and Chadin2 dams have been available since November 2009 and November 2011, respectively. The energy is to supply mines in the Cajamarca Region, La Libertad, Ancash Region, and Piura Region, according to a 2011 law. In 2013, Peruvian President Ollanta Humala explicitly made a connection with mining, saying that the energy is to supply mines in the Cajamarca Region, La Libertad, Ancash Region, and Piura Region. In 2012, work on the 406 MW dam in Chaglla District began.

Total Length: 1,079 miles (shared with Ecuador)