The Upamayo Dam (possibly from Quechua upa calm, silent; mute, mayu river) is a dam at Lake Junin, the largest lake entirely in Peru. It is located on the border of the Junín Region, Junín Province, Ondores District, and the Pasco Region, Pasco Province, Vicco District.
The dam was erected in 1936. It is high and long. It is operated by Centromín Perú. The reservoir has a capacity of .
References escale.minedu.gob.pe - UGEL map of the Junín Province (Junín Region) Obras hidraulicos en la cuenca de Mantaro - fuente : fuente: Electroperu - Inventario proyectos de afianzamiento hidrico Cuenca del Rio Mantaro, 2005 Recursos Hídricos del Perú en Cifras, Boletín Técnico de Recursos Hídricos 2010, Autoridad Nacional del Agua, Ministerio de Agricultura, Perú