Some key facts about Akosombo Dam

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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.

The construction of the dam flooded part of the Volta River Basin and led to the subsequent creation of Lake Volta.

Here are some key facts and stats about the Akosombo Dam:

• Location: Akosombo, Ghana

• Construction: 1961 – 1965

• Type of Dam: Rock fill Embankment Dam

• Height: 114 m (374 ft)

• Length of main Dam at crest: 660m (2,165.33ft)

• Length of Saddle Dam: 355m (1, 164.68ft)

• Reservoir: Storage Reservoir

• Water Course: Volta River

• Area of Lake: 8,502 sq. km

• Capacity of Lake: 148 x 10^12 litres

• Shoreline: 7,250 km

• Length of Lake: 400 km

• Net Generation: 6,502,784,456 kwh

• Hydraulic Height: 68.8 metres (226 ft.)

• Spillway Capacity at Elevation Drainage Area: 34,000 m3/s (1,200,000 cu ft/s)

• Probable Maximum Flood (PMF) (Inflow): 32,042 m3/s

• Probable Maximum Flood (PMF) (Outflow): 23,010 m3/s

• Maximum Operating Level: 84.73m (278ft)

• Minimum Operating Level: 73.15m (240ft)

• Maximum Water Level ever recorded: 84.59m (277.54ft) on 8th November, 2010

• Minimum Water Level ever recorded: 71.62m (234.96ft) on 21st July, 2007

• Maximum Annual Inflow ever recorded: 62.09 MAF in 1968

• Minimum Annual Inflow ever recorded: 6.20 MAF in 1983

• Turbine: Francis, Vertical shaft

• Manufacturer: VA Tech, Voest Alpine, Austria

• Unit output: 173.1MW (222000hp) (Retrotted Units)

• Head (Max): 68.88m (226ft)

• Synchronous speed: 115.4 Rev/Min

• Generator Rating: 179.5MVA at 14.4KV, 0.95PF

• Manufacturer: General Electric, Canada

• Exciter Type: Static (SILCO-5)

• Manufacturer: General Electric, Canada

• Unit Transformer Type: Outdoor 3phase

• Rating: 200/MVA, 14.4/161KV

• Cooling: OFAF

• Manufacturer: Areva, Turkey

• Governor Type: Digital/Hydraulic

• Manufacturer: Andritz Hydro, Austria

• Penstock Type: Steel, one per unit

• Diameter: 7.2m (24ft)

• Total Cost of Project: $196,000,000

Financial Support: International Bank for Reconstruction & Development, United Kingdom Government, Export & Import (Exim) Bank, United States (US) Aid, Ghana Government.

The primary purpose of the Akosombo Dam was to provide electricity for the aluminum industry. 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.

The large electric-power-generating capacity (912 megawatts) of the Akosombo Dam meets Ghana’s needs and provides a surplus for sale to neighboring countries. The dam supplies electricity to a large, economically important aluminum smelter in the coastal town of Tema.

Lake Volta is the largest man-made lake in the world by surface area. It covers 8,502 square kilometers (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.

The Akosombo Dam benefited some industrial and economic activities from the addition of lake transportation, increased fishing, new farming activities along the shoreline, and tourism.

By:The writer, Ebenezer Amanor, writes for surveillanceghana.com