Gariep Dam
Gariep Dam
Location of Gariep Dam in South Africa
Official name	Gariep Dam
Location	Border of Eastern Cape and Free State, South Africa
Coordinates	30°37′25.43″S 25°30′23.81″E / 30.6237306°S 25.5066139°E / -30.6237306; 25.5066139
Construction began	1965
Opening date	1971
Owner(s)	Department of Water Affairs
Dam and spillways
Type of dam	Arch-gravity dam
Impounds	Orange River
Height	88 m (289 ft)
Length	914 m (2,999 ft)
Reservoir
Creates	Gariep Dam Reservoir
Total capacity	5,340,000 megalitres (5,340 hm3; 5.34×109 m3)[1]
Surface area	374 km2 (144 sq mi)
Power Station
Operator(s)	Eskom
Turbines	4 x 90 MW (120,000 hp)
Installed capacity	360 MW (480,000 hp) (max)
Annual generation	889 GWh (3,200 TJ)[2]

The Gariep Dam is located in South Africa, near the town of Norvalspont, bordering the Free State and Eastern Cape provinces. Its primary purpose is for irrigation, domestic and industrial use as well as for power generation.

Name

The Gariep Dam, on its commission in 1971, was originally named the Hendrik Verwoerd Dam after Hendrik Verwoerd, the Prime Minister before and after 31 May 1961, when the country changed from the Union of South Africa to the Republic of South Africa. However, after the end of apartheid, the Verwoerd name was considered unsuitable. The name was officially changed to Gariep Dam on 4 October 1996. Gariep is Khoekhoe for "river", the original name of the Orange River.^[3]

Location

The dam is on the Orange River about 48 kilometres (30 mi) north-east of Colesberg and 208 kilometres (129 mi) south of Bloemfontein. It is in a gorge at the entrance to the Ruigte Valley some 5 kilometres (3.1 mi) east of Norvalspont. The dam crest is some 1300 m (4250 ft) above sea level.

Dimensions

The wall is 88 m high and has a crest length of 914 m and contains approximately 1.73 million m³ of concrete. The Gariep Dam is the largest storage reservoir in South Africa. In South African English, 'dam' refers both to the structure and the water volume it retains. Gariep Dam has a total storage capacity of approximately 5,340,000 megalitres (5,340 hm³) and a surface area of more than 370 square kilometres (140 sq mi) when full. The hydro-electrical power station houses four 90 MW generators.

Design type and contractors

The structure is a concrete gravity-arch hybrid dam. This design was chosen as the gorge is too wide for a complete arch so flanking walls form gravity abutments to the central arch.

It was built by Dumez, a French construction company.

Gariep Dam Bridge

Rivers and spruits flowing into the dam

• Orange River^[4]
• Caledon River^[4]
• Brakspruit^[4]
• Broekspruit^[4]
• Oudagspruit^[4]
• Palmietspruit^[4]
• Slykspruit^[4]

Water consumption, outflow, derivative usages and diversions

It must be carefully managed by balancing the supply-and-demand of this water resource usage for its derivatives of electricity generation, irrigation(food) and municipal drinking water.

Department of Water - Orange River Basin - Map and flow diagrams Archived 2022-06-16 at the Wayback Machine

Orange-Fish River Project

At Oviston, on the south bank of the reservoir, is the inlet of the Orange-Fish River Tunnel, allowing water to be diverted to the Great Fish River and most of the Eastern Cape's western parts.

There is trade off in the water usage for electricity and inter-basin transfer for water in other areas like Port Elizabeth
Orange-Fish River Tunnel Basin Transfer Schema construction 1972 (Port Elizabeth) on YouTube

Gallery

• 
  Gariep Dam overflowing in January 2011
• 
  Sunset at Oviston Nature Reserve on the dam's southern shores
• 
  Road sign heading for the dam wall
• 
  View over the lake
• 
  Forever Holiday Resort at Gariep Dam

See also

• List of rivers of South Africa
• List of reservoirs and dams in South Africa

References

External links