Gariep Dam

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°ECoordinates: 30°37′25.43″S 25°30′23.81″E / 30.6237306°S 25.5066139°E
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 hm^3)[1]
Surface area	374 km^2 (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]

Gariep Dam is 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 was originally named the Hendrik Verwoerd Dam after the first prime minister of the Republic of South Africa Hendrik Verwoerd on its commission in 1971. 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.

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 lake it impounds. 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, giving a maximum output of 360 MW of electricity at a water flow rate of 800 m³/s.

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

Gariep Dam bridge
Carries	14300 tons
Characteristics
Width	Doubleway
Statistics
Toll	None

Rivers and spruits flowing into the dam

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

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.

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

1. "State of Dams in Provinces as on 20080901". Department of Water Affairs and Forestry. Retrieved 2008-09-07.
2. Eskom website
3. "Dictionary of Southern African Place Names (Public Domain)". Human Science Research Council. p. 171.
4. Dept of Water Affairs website

External links

• Gariep Hydroelectric Power Station on the Eskom-Website