Steenbras Dam

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 mountains, above Gordons Bay, near Cape Town in South Africa. In 1916 a Board of Engineers was appointed to report on a water augmentation scheme for the city. 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).[1]

Steenbras Dam
Steenbras Dam, seen wedged between the Hottentots-Holland and Kogelberg ranges (top), with False Bay below and right
Location of Steenbras Dam in South Africa
Official name	Steenbras Dam
Country	South Africa
Location	Western Cape, Gordon's Bay
Coordinates	34°11′12.61″S 18°51′9.11″E
Purpose	Irrigation and domestic
Opening date	1921 (renovated 1989)
Owner(s)	City of Cape Town
Dam and spillways
Type of dam	Concrete arch dam
Impounds	Steenbras River
Height	28 m
Length	1700 m
Reservoir
Creates	Steenbras Dam
Total capacity	33 517 000 m3
Catchment area	66.7 km2
Surface area	380 ha

There is a hydroelectric plant at the dam. The Steenbras pumped-storage scheme was opened in 1979 to supplement Cape Town's electricity supply during periods of peak demand.

The dam is on the Steenbras River, 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.[2][3]

Steenbras Upper Dam is directly upstream and is used for the Steenbras Power Station (pumped storage).[4]

The City of Cape Town is investigating strengthening and raising the wall to increase Steenbras Dam's capacity.