Vaal dam
Encyclopedia
The Vaal Dam in South Africa
was constructed in 1938 and lies 77 km south of OR Tambo International Airport Formerly Jan Smuts Airport, then renamed Johannesburg International Airport
in 1994, before being renamed yet again on 27th October 2006 as ORT. The lake behind the dam wall has a surface area of about 320 square kilometres (123.6 sq mi) and is 47 meters deep. The Vaal Dam lies on the Vaal River
, which is one of South Africa's strongest-flowing rivers. It has over 800 kilometres (497.1 mi) of shoreline and is South Africa's second biggest dam by area and the third largest by volume.
The dam was subsequently raised in the early fifties to a height of 60.3 metres (197.8 ft) which increased the capacity to 2188000000 cubic metres (77,268,489,673.3 cu ft). A second raising took place in 1985 when the wall was raised by a further 3.05 metres (10 ft) to 63.4 metres (208 ft) above lowest foundation. The capacity of the dam is currently 2536000000 cubic metres (89,557,993,515.3 cu ft) and a further 663000000 cubic metres (23,413,623,699 cu ft) or 26% can be stored temporarily for flood attenuation.
The flood attenuation properties of the dam were severely tested in February 1996 when the largest flood ever recorded at the Vaal Dam site was experienced. An inflow of over 4700 m3/s was measured into the Vaal Dam which was already at full capacity due to good rains and it was only through the expert management of the Hydrology staff at DWAF that the maximum flood released from the dam was limited to 2300 m3/s. Flows above 2300 m3/s would have caused serious damage downstream of Vaal Dam and the situation during the 1996 flood became extremely tense as the storage in the reservoir peaked at 118.5% of Full Supply Capacity on 19 February 1996 i.e. only 194000000 cubic metres (6,851,045,245.3 cu ft) of flood absorption capacity remained before the full inflow would have been released causing massive damage.
The Lesotho Highlands Water Project
pumps water into the system in order to supply water to the people and industrial complex of Gauteng
. This water is piped from Lesotho into the Liebenbergsvlei and Wilge Rivers.
The Sterkfontein Dam
forms part of the Tugela-Vaal water transfer scheme for the interbasin transfer
of water from the Thukela River in KwaZulu-Natal
to boost the levels in the Vaal River System. Water from the Sterkfontein Dam is released once the Vaal Dam drops to below 16%.
The dam has its own island some 5 km (3 mi) long. The island was used as a secret meeting place by the apartheid government but now hosts the annual Round the Yacht race, a Guinness Book of World Records title of the largest inland yacht race.
On 4 May 1948 BOAC
introduced Short Solent
flying boats on the UK (Southampton) to South Africa (Vaaldam) service. The small village of Deneysville
was used as a stop-over point by the old BOAC
flying boats.
Three provinces make up the Dam's shoreline - the Free State
is the largest by area, Mpumalanga
has a beautiful and relatively unspoilt shoreline, while the most despoiled by far is that of Gauteng
. The dam was commissioned in 1939, has a capacity of 2.536 cubic kilometre, and a surface area of 320 square kilometres (123.6 sq mi), the dam wall is 63 metres (206.7 ft) high. Due to the large lake size reservoir there is a problem with evaporation, see Sterkfontein Dam
for more details.
Deneysville
is the largest town on the Vaal Dam and provides the shopping centre for the Dam. There are Three yacht clubs and two Marinas the famous "Round The Island" yacht race is held at the Lake Deneys Yacht Club. This race has entered the Guinness Book of Records for the most boats in an inland yacht race.
More information on Deneysville including types of Accommodation available as well as information can be had from http://www.deneysville.com
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...
was constructed in 1938 and lies 77 km south of OR Tambo International Airport Formerly Jan Smuts Airport, then renamed Johannesburg International Airport
Johannesburg International Airport
OR Tambo International Airport is a large airport in Kempton Park, Ekurhuleni, Gauteng, South Africa, near the city of Johannesburg. It serves as the primary airport for domestic and international travel to/from South Africa and is Africa's busiest airport with a capacity handle up to 28,000,000...
in 1994, before being renamed yet again on 27th October 2006 as ORT. The lake behind the dam wall has a surface area of about 320 square kilometres (123.6 sq mi) and is 47 meters deep. The Vaal Dam lies on the Vaal River
Vaal River
The Vaal River is the largest tributary of the Orange River in South Africa. The river has its source in the Drakensberg mountains in Mpumalanga, east of Johannesburg and about 30 km north of Ermelo and only about 240 km from the Indian Ocean. It then flows westwards to its conjunction...
, which is one of South Africa's strongest-flowing rivers. It has over 800 kilometres (497.1 mi) of shoreline and is South Africa's second biggest dam by area and the third largest by volume.
History
The construction of Vaal Dam started during the depression of the early thirties and the dam was completed in 1938 with a wall height of 54.2 metres (177.8 ft) above lowest foundation and a full supply capacity of 994000000 cubic metres (35,102,778,215.4 cu ft). The dam is a concrete gravity structure with an earthfill section on the right flank. It was built as a joint venture by Rand Water and the Department of Irrigation (now known as the Department of Water Affairs and Forestry).The dam was subsequently raised in the early fifties to a height of 60.3 metres (197.8 ft) which increased the capacity to 2188000000 cubic metres (77,268,489,673.3 cu ft). A second raising took place in 1985 when the wall was raised by a further 3.05 metres (10 ft) to 63.4 metres (208 ft) above lowest foundation. The capacity of the dam is currently 2536000000 cubic metres (89,557,993,515.3 cu ft) and a further 663000000 cubic metres (23,413,623,699 cu ft) or 26% can be stored temporarily for flood attenuation.
The flood attenuation properties of the dam were severely tested in February 1996 when the largest flood ever recorded at the Vaal Dam site was experienced. An inflow of over 4700 m3/s was measured into the Vaal Dam which was already at full capacity due to good rains and it was only through the expert management of the Hydrology staff at DWAF that the maximum flood released from the dam was limited to 2300 m3/s. Flows above 2300 m3/s would have caused serious damage downstream of Vaal Dam and the situation during the 1996 flood became extremely tense as the storage in the reservoir peaked at 118.5% of Full Supply Capacity on 19 February 1996 i.e. only 194000000 cubic metres (6,851,045,245.3 cu ft) of flood absorption capacity remained before the full inflow would have been released causing massive damage.
The Lesotho Highlands Water Project
Lesotho Highlands Water Project
The Lesotho Highlands Water Project is an ongoing water supply project with a hydropower component, developed in partnership between the governments of Lesotho and South Africa. It comprises a system of several large dams and tunnels throughout Lesotho and South Africa. In Lesotho, it involves the...
pumps water into the system in order to supply water to the people and industrial complex of Gauteng
Gauteng
Gauteng is one of the nine provinces of South Africa. It was formed from part of the old Transvaal Province after South Africa's first all-race elections on 27 April 1994...
. This water is piped from Lesotho into the Liebenbergsvlei and Wilge Rivers.
The Sterkfontein Dam
Sterkfontein Dam
The Sterkfontein Dam, located just outside the town of Harrismith, in the Free State, province of South Africa, is part of the Tugela-Vaal Water Project, and located on the Nuwejaarspruit, in the upper catchment area of the Vaal River...
forms part of the Tugela-Vaal water transfer scheme for the interbasin transfer
Interbasin transfer
Interbasin transfer or transbasin diversion are terms used to describe man-made conveyance schemes which move water from one river basin where it is available, to another basin where water is less available or could be utilized better for human development...
of water from the Thukela River in KwaZulu-Natal
KwaZulu-Natal
KwaZulu-Natal is a province of South Africa. Prior to 1994, the territory now known as KwaZulu-Natal was made up of the province of Natal and the homeland of KwaZulu....
to boost the levels in the Vaal River System. Water from the Sterkfontein Dam is released once the Vaal Dam drops to below 16%.
The dam has its own island some 5 km (3 mi) long. The island was used as a secret meeting place by the apartheid government but now hosts the annual Round the Yacht race, a Guinness Book of World Records title of the largest inland yacht race.
On 4 May 1948 BOAC
British Overseas Airways Corporation
The British Overseas Airways Corporation was the British state airline from 1939 until 1946 and the long-haul British state airline from 1946 to 1974. The company started life with a merger between Imperial Airways Ltd. and British Airways Ltd...
introduced Short Solent
Short Solent
- External links :* * *...
flying boats on the UK (Southampton) to South Africa (Vaaldam) service. The small village of Deneysville
Deneysville
Deneysville is a small town on the banks of the Vaal Dam in the Free State province of South Africa. It has been dubbed the "Inland Water Mecca of South Africa"....
was used as a stop-over point by the old BOAC
British Overseas Airways Corporation
The British Overseas Airways Corporation was the British state airline from 1939 until 1946 and the long-haul British state airline from 1946 to 1974. The company started life with a merger between Imperial Airways Ltd. and British Airways Ltd...
flying boats.
Water Sports
Many world class watersport events are held here including the annual "Round The Island" yacht race organized by Lake Deneys Yacht Club— a race that has been in the Guinness Book of Records for being the "Longest Inland Yacht Race in the World". Several large events take place here including Keelboat Week and the Bayshore 200 km jetski race, and now the Bayshore Marina Vaal Dam Treasure Hunt.Three provinces make up the Dam's shoreline - the Free State
Free State
The Free State is a province of South Africa. Its capital is Bloemfontein, which is also South Africa's judicial capital. Its historical origins lie in the Orange Free State Boer republic and later Orange Free State Province. The current borders of the province date from 1994 when the Bantustans...
is the largest by area, Mpumalanga
Mpumalanga
Mpumalanga , is a province of South Africa. The name means east or literally "the place where the sun rises" in Swazi, Xhosa, Ndebele and Zulu. Mpumalanga lies in eastern South Africa, north of KwaZulu-Natal and bordering Swaziland and Mozambique. It constitutes 6.5% of South Africa's land area...
has a beautiful and relatively unspoilt shoreline, while the most despoiled by far is that of Gauteng
Gauteng
Gauteng is one of the nine provinces of South Africa. It was formed from part of the old Transvaal Province after South Africa's first all-race elections on 27 April 1994...
. The dam was commissioned in 1939, has a capacity of 2.536 cubic kilometre, and a surface area of 320 square kilometres (123.6 sq mi), the dam wall is 63 metres (206.7 ft) high. Due to the large lake size reservoir there is a problem with evaporation, see Sterkfontein Dam
Sterkfontein Dam
The Sterkfontein Dam, located just outside the town of Harrismith, in the Free State, province of South Africa, is part of the Tugela-Vaal Water Project, and located on the Nuwejaarspruit, in the upper catchment area of the Vaal River...
for more details.
Deneysville
Deneysville
Deneysville is a small town on the banks of the Vaal Dam in the Free State province of South Africa. It has been dubbed the "Inland Water Mecca of South Africa"....
is the largest town on the Vaal Dam and provides the shopping centre for the Dam. There are Three yacht clubs and two Marinas the famous "Round The Island" yacht race is held at the Lake Deneys Yacht Club. This race has entered the Guinness Book of Records for the most boats in an inland yacht race.
See also
- Vaal RiverVaal RiverThe Vaal River is the largest tributary of the Orange River in South Africa. The river has its source in the Drakensberg mountains in Mpumalanga, east of Johannesburg and about 30 km north of Ermelo and only about 240 km from the Indian Ocean. It then flows westwards to its conjunction...
- Lesotho Highlands Water ProjectLesotho Highlands Water ProjectThe Lesotho Highlands Water Project is an ongoing water supply project with a hydropower component, developed in partnership between the governments of Lesotho and South Africa. It comprises a system of several large dams and tunnels throughout Lesotho and South Africa. In Lesotho, it involves the...
- Sterkfontein DamSterkfontein DamThe Sterkfontein Dam, located just outside the town of Harrismith, in the Free State, province of South Africa, is part of the Tugela-Vaal Water Project, and located on the Nuwejaarspruit, in the upper catchment area of the Vaal River...
More information on Deneysville including types of Accommodation available as well as information can be had from http://www.deneysville.com