El Chocón Dam

The El Chocón Dam (in Spanish, "La Presa de El Chocón") is the fourth of five dams on the Limay River in the northwestern Argentine Patagonia (the Comahue region), approximately at coord|39|17|S|68|48|W|, 381 m above mean sea level.

El Chocón is used to regulate the flow of the Limay River, for irrigation, and for the generation of hydroelectricity. Its power station is the largest hydroelectric power plant in Patagonia, with a capacity of 1,200 MW. It was built by the state-owned company Hidronor (Hidroeléctrica Norpatagónica). It started operating in 1973, and achieved full capacity in 1978. In the period 1974–1995 it produced an annual average of 2,700 GWh. In 1993 it was privatized, with an exploitation concession granted to Hidroeléctrica El Chocón S. A.

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.

El Chocón is on the Limay River at about 80km upstream of its confluence with the Neuquén River.

Dr. Ing. Fabián Restelli , HECSA - Hidroeléctrica El Chocón S.A.

Technical details

The dam is made of earth, with a concrete spillway. About 13 million m³ of materials were used. It measures 2,500 m in length. Its maximum height over the river bed is 71 m.

The reservoir has a maximum area of 816 km², a mean depth of 24.7 m (maximum 60 m), and a maximum volume of 2.0155×10¹⁰ m³. It is used for sailing, sport fishing and other forms of recreation by locals and tourists.

The power plant has six vertical Francis turbines, with a nominal power of 204.5 MW each, which rotate at 88 rpm. The apparent powers are of 222 MVA for each generator, and 180 MVA for each transformer.

References

* Secretaría de Energía, República Argentina. El Chocón ( [http://energia.mecon.gov.ar/contenidos/contenidos.asp?id=568 part 1] , [http://energia.mecon.gov.ar/contenidos/contenidos.asp?id=608 part 2] ).