| Wemmershoek Dam | |
|---|---|
 Interactive map of Wemmershoek Dam | |
| Location | Western Cape,South Africa |
| Coordinates | 33°50′1″S19°5′20″E / 33.83361°S 19.08889°E /-33.83361; 19.08889 |
| Purpose | Water supply |
| Opening date | 1957 |
| Owner | City of Cape Town |
| Dam and spillways | |
| Type of dam | Rock-fill dam |
| Impounds | Wemmershoek River |
| Height | 55 m (180 ft) |
| Length | 518 m (1,699 ft) |
| Reservoir | |
| Creates | Wemmershoek Dam Reservoir |
| Total capacity | 58,644 Ml (2,071.0×10 |
| Catchment area | 86 km2 (33 sq mi) |
| Surface area | 296 ha (730 acres) |
Wemmershoek Dam is a rock-fill type dam located on theWemmershoek River nearFranschhoek andPaarl inSouth Africa. It was constructed between 1953 and 1957 on behalf of theCity of Cape Town. With a reservoir capacity of 58,644 megalitres (2,071.0×10^6 cu ft), it provides approximately 6.5% of the storage capacity of theWestern Cape Water Supply System which suppliesCape Town and surrounding areas.
As early as 1882 theCape Colony's hydrographic surveyor reported on the potential of the Wemmershoek valley for water supply. In 1899 the municipal council ofWoodstock, then an independent suburb of Cape Town, began purchasing land at Wemmershoek with the aim of building a reservoir. In 1907 the councils of Woodstock,Mowbray,Rondebosch andClaremont obtained aprivate bill from thecolonial parliament authorising the construction of a small dam at Wemmershoek.[1]
In 1913 the four suburban councils were incorporated into theCity of Cape Town, which took over their rights at Wemmershoek. Water shortages demanded that Cape Town, which had until then relied on water supplies fromTable Mountain, find a source of water from outside the Cape Peninsula. The two leading candidates were the Wemmershoek catchment and the Steenbras catchment in theHottentots Holland mountains. A ratepayers' referendum decided on Steenbras which led to the construction of theSteenbras Dam starting in 1918.[1]
After the Second World War, with the growth of Cape Town's urban population, the city again needed to find an additional water supply. The Wemmershoek scheme was revived, and a new private bill was passed by Parliament in 1951 for the construction of a larger dam. Construction began in 1953 and was completed in 1957.[1]
The dam wall is ofrock-fill type with a clay core.[1] It is 518 metres (1,699 ft) long and 55 metres (180 ft) tall at its highest point. The dam impounds a reservoir of 58,644 megalitres (2,071.0×10^6 cu ft) capacity which, when full, covers an area of 296 hectares (730 acres). Its catchment area in the Wemmershoek Mountains covers an area of 86 square kilometres (33 sq mi).[2] Anintake tower draws water into a pipeline which supplies a water treatment plant at the foot of the dam. Releases of water into the Wemmershoek River are by way of a gate-controlledspillway with a maximum flow of 1,065 cubic metres per second (37,600 cu ft/s).[1]
