The El Chocón Dam (Spanish: Represa El Chocón Cerros Colorados) is the fourth of the five dams on the Limay River in the northwestern Argentine Patagonia (the Comahue region), at 381 metres (1,250 ft) above mean sea level.
El Chocón Cerros Colorados is used to regulate the flow of the Limay River, for irrigation, and for the generation of hydroelectricity.
While the formal name of the project is Embalse Ezequiel Ramos Mexía, in common use it ended up acquiring the name of the settlement that served as the construction's base of operations, Villa El Chocón (a small town, population 957, as of 2001).
El Chocón is part of a larger engineering scheme that also includes the Cerros Colorados Complex, on the Neuquén River.
The Hydroelectric Complex which holds El Chocón and Arroyito Hydroelectric Power Plants, is located in the region known as Comahue, which is formed by the Argentine provinces of Río Negro and Neuquén and the southern area of the Buenos Aires and La Pampa provinces.