The Rapel Dam is an

arch dam An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengtheni ...

on the

Rapel River Rapel River is a List of rivers in Chile, river of Chile located in the O'Higgins Region. It begins at the confluence of the rivers Cachapoal River, Cachapoal and Tinguiririca River, Tinguiririca in an area best known as ''La Junta''. At present d ...

about north of La Estrella in the

Libertador General Bernardo O'Higgins Region The Libertador General Bernardo O'Higgins Region (, ), often shortened to O'Higgins Region (), is one of Chile's 16 first order administrative divisions. It is subdivided into three provinces. It is named in honour of Bernardo O'Higgins Riquel ...

, Chile. The primary purpose of the dam is hydroelectric power generation and it supports a 377 MW power station. The dam was completed in 1968 and is owned by

Endesa Endesa, S.A. (, originally an initialism for ''Empresa Nacional de Electricidad, S.A''.) is a Spanish multinational electric utility company, the largest in the country. The firm, a majority-owned subsidiary of the Italian utility company Enel, ...

. It creates the largest

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

in Chile with a capacity of . The dam withstood the 7.5 M_w

1985 Rapel Lake earthquake The 1985 Rapel Lake earthquake occurred on 8 April at with a moment magnitude of 7.2 and a maximum perceived intensity of VI (''Strong''). The shock was centered southwest of Santiago, Chile, with a focal depth of . Earthquake The 9 April 19 ...

with only minor damage. It was centered from the dam.

Design

The Rapel Dam is a tall and long variable-radius arch-type. It is wide at its crest and wide at its base. The dam's

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

is controlled by five

tainter gate The Tainter gate is a type of radial arm floodgate used in dams and canal locks to control water flow. It is named for its inventor, the Wisconsin structural engineer Jeremiah Burnham Tainter. Tainter, an employee of the lumber firm Knapp, ...

s and has a discharge capacity of . The dam's reservoir,

Lake Rapel Rapel Lake (Spanish: ''Lago Rapel'' or ''Embalse Rapel'') is an artificial lake created by a dam on the Rapel River. It is located in the Libertador General Bernardo O'Higgins Region, Central Chile. The reservoir was created with the aim of feedi ...

has a capacity of which is active capacity.

Power station

The power station, located at the dam's base, contains five

Francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The pro ...

-generators and is afforded of net

hydraulic head Hydraulic head or piezometric head is a measurement related to liquid pressure (normalized by specific weight) and the liquid elevation above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22, eq.3.2a. It is usually meas ...

References

{{Authority control Dams completed in 1968 Dams in Chile Arch dams Geography of O'Higgins Region