The Steenbras Dam ("STEE-un bruss"), now referred to as Steenbras Lower Dam, is a gravity concrete arch type dam located in the

Hottentots-Holland The Hottentots Holland Mountains are part of the Cape Fold Belt in the Western Cape, South Africa. The mountain range forms a barrier between the Cape Town metropolitan area and the southern Overberg coast. The range is primarily composed of Ta ...

mountains, above Gordons Bay, near

Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. It is one of the six large dams that make up the

Western Cape Water Supply System The Western Cape Water Supply System (WCWSS) is a complex water supply system in the Western Cape region of South Africa, comprising an inter-linked system of six main dams, pipelines, tunnels and distribution networks, and a number of minor dams ...

. It is owned by the

City of Cape Town The City of Cape Town ( af, Stad Kaapstad; xh, IsiXeko saseKapa) is the metropolitan municipality which governs the city of Cape Town, South Africa and its suburbs and exurbs. As of the 2011 census, it had a population of 3,740,026. The remo ...

and serves principally to supply water to that city. The dam wall is high and long; it impounds a reservoir of over a surface area of when full. In 1916 a Board of Engineers was appointed to report on a water augmentation scheme for the

. Their proposal was the Steenbras scheme which would consist of a concrete gravity and arch dam on the Steenbras River. This dam would be connected to the Molteno reservoir through a tunnel in the Hottentots Holland mountains and a 64 kilometre long cast iron pipeline. Work began on the scheme in 1918 and was completed three years later. The Steenbras scheme could supply Cape Town with up to 42 million litres of water per day although the average consumption was in the region of 29 million litres per day. The consumption however grew rapidly and it was not long before Cape Town once again had a water supply problem. To solve the demand for additional water supplies the Steenbras dam wall was raised and an additional pipeline was laid into the city. This work was completed in 1928. For much of the first half of the twentieth century it was the main reservoir for Cape Town but is now only one of many dams that supply the city. The hazard potential of Steenbras has been ranked high (3). Steenbras Dam catchment map

The dam is on the

Steenbras River ''Lithognathus'' is ''a'' marine fish genus in the family Sparidae, members of which are commonly known as steenbras. They are primarily found in coastal regions in Southern Africa (South Africa, Namibia and Angola), but ''L. mormyrus'' also occ ...

, which, in common with most rivers in the Western Cape, has a low sediment load and delivers water of very high quality. The river and dam are named after the steenbras, a fish endemic to South Africa. Pipe Line Brigde across the Lorensford River

Pipe Line Brigde across the Lorensford River

In 1977 the Steenbras Upper Dam was constructed directly upstream. It is used for the Steenbras pumped-storage hydroelectricity scheme which supplements Cape Town's electricity supply during periods of peak demand. The City of Cape Town is investigating strengthening and raising the wall to increase Steenbras Dam's capacity.

References

Dams in South Africa Buildings and structures in the Western Cape {{SouthAfrica-dam-stub