Woodhead Dam
Encyclopedia
Woodhead Dam is a dam
on Table Mountain
, Western Cape
, South Africa
. It was built in 1897 and supplies water to Cape Town
. The dam, which was the first large masonry dam in South Africa, was designated as an International Historic Civil Engineering Landmark by the American Society of Civil Engineers
in 2008.
led to shortages of drinking water. It was decided to build a reservoir
on Table Mountain to provide water to the city. Scottish hydraulic engineer
Thomas Stewart
was engaged to design and build the reservoir.
The Woodhead Tunnel was built between 1888 and 1891. It was used to divert the Disa Stream, a tributary of the Hout Bay River, westward to provide water for the reservoir.
An aerial cableway
was constructed to transport men and materials to the construction site. The dam was constructed between 1894 and 1897. This dam was followed by four others in the area. The Hely-Hutchinson Dam and reservoir was built by 1904 just upstream of the Woodhead reservoir. The Alexandra Dam and Victoria Dam were built on the original Disa Stream by 1903. The last of the five dams was the Villiers Dam in 1907. This was built downstream of the Alexandra and Victoria Dams. Today, these five dams supply around 15% of the water for Cape Town.
with a capacity of 20 m3/s (706 ft3/s). The reservoir has a capacity of 927000 cubic metre and a surface area of 13 hectares (32 acre).
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
on Table Mountain
Table Mountain
Table Mountain is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa, and is featured in the flag of Cape Town and other local government insignia. It is a significant tourist attraction, with many visitors using the cableway or hiking to the top...
, Western Cape
Western Cape
The Western Cape is a province in the south west of South Africa. The capital is Cape Town. Prior to 1994, the region that now forms the Western Cape was part of the much larger Cape Province...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. It was built in 1897 and supplies water to Cape Town
Cape Town
Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
. The dam, which was the first large masonry dam in South Africa, was designated as an International Historic Civil Engineering Landmark by the American Society of Civil Engineers
American Society of Civil Engineers
The American Society of Civil Engineers is a professional body founded in 1852 to represent members of the civil engineering profession worldwide. It is the oldest national engineering society in the United States. ASCE's vision is to have engineers positioned as global leaders who strive toward...
in 2008.
History
In 1870, the growth of Cape TownCape Town
Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
led to shortages of drinking water. It was decided to build a reservoir
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...
on Table Mountain to provide water to the city. Scottish hydraulic engineer
Hydraulic engineering
This article is about civil engineering. For the mechanical engineering discipline see Hydraulic machineryHydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive...
Thomas Stewart
Thomas Stewart (civil engineer)
Thomas Stewart was a hydraulic engineer, who was born in Scotland and died at Cape Town, South Africa. He designed the Woodhead Dam, which was named an International Historic Civil Engineering Landmark by the American Society of Civil Engineers in 2008...
was engaged to design and build the reservoir.
The Woodhead Tunnel was built between 1888 and 1891. It was used to divert the Disa Stream, a tributary of the Hout Bay River, westward to provide water for the reservoir.
An aerial cableway
Aerial tramway
An aerial tramway , cable car , ropeway or aerial tram is a type of aerial lift which uses one or two stationary ropes for support while a third moving rope provides propulsion...
was constructed to transport men and materials to the construction site. The dam was constructed between 1894 and 1897. This dam was followed by four others in the area. The Hely-Hutchinson Dam and reservoir was built by 1904 just upstream of the Woodhead reservoir. The Alexandra Dam and Victoria Dam were built on the original Disa Stream by 1903. The last of the five dams was the Villiers Dam in 1907. This was built downstream of the Alexandra and Victoria Dams. Today, these five dams supply around 15% of the water for Cape Town.
Design
The Woodhead Tunnel is 640 m (2,100 ft) long. The Woodhead Dam is a masonry gravity dam that is 277 m (909 ft) long and 50 m (164 ft) high. It has a free overspill spillwaySpillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
with a capacity of 20 m3/s (706 ft3/s). The reservoir has a capacity of 927000 cubic metre and a surface area of 13 hectares (32 acre).