Akosombo Dam | |
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Akosombo Dam as seen from the Volta Hotel | |
Location | Akosombo, Ghana |
Coordinates | 6°17′59″N 0°3′34″E / 6.29972°N 0.05944°E |
Status | Operational |
Construction began | 1961 |
Opening date | 1965 |
Construction cost | £130 million in 1965 (2.1 billion pounds when adjusted for inflation) |
Owner(s) | Volta River Authority |
Dam and spillways | |
Type of dam | Embankment, rock-fill |
Impounds | Volta River |
Height (foundation) | 114 m (374 ft) |
Length | 660 m (2,170 ft) |
Width (base) | 366 m (1,201 ft) |
Dam volume | 7,900,000 m3 (280,000,000 cu ft) |
Spillways | Twin gate-controlled |
Spillway capacity | 34,000 m3/s (1,200,000 cu ft/s) |
Reservoir | |
Creates | Lake Volta |
Total capacity | 148 km3 (120,000,000 acre⋅ft) |
Surface area | 8,502 km2 (3,283 sq mi) |
Maximum length | 400 km (250 mi) |
Power Station | |
Hydraulic head | 68.8 m (226 ft) (max) |
Turbines | 6 x 170 MW (230,000 hp) Francis-type |
Installed capacity | 1,038 MW (1,392,000 hp) |
Website www |
The Akosombo Dam, also known as the Volta Dam, is a hydroelectric dam on the Volta River in southeastern Ghana in the Akosombo gorge and part of the Volta River Authority.[1] The construction of the dam flooded part of the Volta River Basin and led to the subsequent creation of Lake Volta. Lake Volta is the largest man-made lake in the world by surface area. It covers 8,502 square kilometres (3,283 sq mi), which is 3.6% of Ghana's land area. With a volume of 148 cubic kilometers, Lake Volta is the world's third largest man-made lake by volume; the largest being Lake Kariba which contains 185 cubic kilometers of water.[2]
The primary purpose of the Akosombo Dam was to provide electricity for the aluminium industry.[3] The Akosombo Dam was called "the largest single investment in the economic development plans of Ghana."[4] The dam is significant for providing the majority of both Togo and Benin's electricity, although the construction of the Adjarala Dam (on Togo's Mono River) hopes to reduce these countries' reliance on imported electricity.[5] The dam's original electrical output was 912 megawatts (1,223,000 hp), which was upgraded to 1,020 megawatts (1,370,000 hp) in a retrofit project that was completed in 2006.[6]
The flooding that created the Lake Volta reservoir displaced many people and had a significant impact on the local environment,[7] including seismic activity that led to coastal erosion; a changed hydrology caused microclimatic changes with less rain and higher temperatures. The soil surrounding the lake is less fertile than the soil under it, and heavy agricultural use has required the use of fertilizers, which in turn has led to eutrophication, which caused, among others, the explosive growth of an invasive weed that renders water navigation and transportation difficult, and form a habitat for the vectors of water-borne illnesses such as bilharzia, river blindness and malaria. Resettlement of the displaced inhabitants proved complex and in some cases unsuccessful; traditional farming practices disappeared and poverty increased.
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