Gariep Dam


Gariep Dam located in South Africa, near the town of Norvalspont, bordering the Free State and Eastern Cape provinces. Its primary purpose is for irrigation, domestic and industrial use as well as for power generation.

Name

The Gariep Dam, on its commission in 1971, was originally named the Hendrik Verwoerd Dam after Hendrik Verwoerd, the Prime Minister before and after 31 May 1961, when the country changed from the Union of South Africa to the Republic of South Africa. However, after the end of apartheid, the Verwoerd name was considered unsuitable. The name was officially changed to Gariep Dam on 4 October 1996. Gariep is Khoekhoe for "river", the original name of the Orange River.

Location

The dam is on the Orange River about north-east of Colesberg and south of Bloemfontein. It is in a gorge at the entrance to the Ruigte Valley some east of Norvalspont. The dam crest is some 1300m above sea level.

Dimensions

The wall is 88 m high and has a crest length of 914 m and contains approximately 1.73 million m³ of concrete. The Gariep Dam is the largest storage reservoir in South Africa. In South African English, 'dam' refers both to the structure and the water volume it retains. Gariep Dam has a total storage capacity of approximately and a surface area of more than when full. The hydro-electrical power station houses four 90 MW generators, giving a maximum output of 360 MW of electricity at a water flow rate of 800 m³/s.

Design type and contractors

The structure is a concrete gravity-arch hybrid dam. This design was chosen as the gorge is too wide for a complete arch so flanking walls form gravity abutments to the central arch.
It was built by Dumez, a French construction company.

Gariep Dam Bridge

Rivers and spruits flowing into the dam

At Oviston, on the south bank of the reservoir, is the inlet of the Orange-Fish River Tunnel, allowing water to be diverted to the Great Fish River and most of the Eastern Cape's western parts.

Gallery