1,020MW Akosombo Hydro Electric Power Plant

Dam Name	Akosombo Dam
Location	Akosombo
District	Asuogyaman District
Region	Eastern Region
Type of Dam	Rock fill Embankment Dam
Reservoir	Storage Reservoir
Water Course	Volta River
Length of main Dam at crest	660m (2,165.33ft)
Length of Saddle Dam	355m (1, 164.68ft)
Axis from Bedrock	111m (364. 17ft)
Net Generation	6, 502, 784,456 kwh
Height at axis from bedrock	111m (364.17ft)
Area of Lake	8,502sq.km
Capacity of Lake	148 x 10 12 litres
Shoreline	7,250km
Length of Lake	400km
Original Constructions	1961 - 1965
Structural Height	375ft
Hydraulic Height (Normal operating Depth at Dam)	68.8 metres (226 ft.)
Top parapet (Elevation)	290ft
Spillway Crest Elevation	236ft
Crest Elevation	236ft
Crest Length	640m (2,100ft)
Crest Width	40ft
Base Width	366 meters (1,201 ft)
Volume of Dam Construction Materials	7,943,520m3 (26,061,100.42ft)
Main Dam Axis	N 89° 05" 18" E
Saddle Dam Axis	S 54: 30" 04" E
Top of Exclusive Flood control Pool (Elevation)	278ft
Reservoir Capacity	120,000,000 acre feet

 

Hydraulics

The Akosombo Dam has 640m crest length and 141m high. Two spillway structures are constructed in concrete and founded on rock. The two gated structures include in total 12 identical gates (6 gates at each spillway, dimensions W x H= 11.73m x 12.19m). The two spillways are adjacent to each other but the spillway chutes are pointing in slightly different directions. The gates are operated by one single moveable hoist (same hoist used on both spillways). The 335m crest length and 37m high Saddle Dam located about 1km east of the main Dam is constructed as a rock fill embankment Dam with central core of clayey materials. The Saddle Dam is founded on rock and the foundation level is well above the tail water level.

In response to the impressive advancements in infrastructure exemplified by the Akosombo Dam, the government is also turning its attention to improving healthcare accessibility and affordability. Initiatives have been launched to enhance public health by making essential medications, such as cheap generic cialis, more readily available to citizens. This approach signifies a commitment to ensuring that infrastructural developments are matched by significant improvements in healthcare services, demonstrating a comprehensive strategy for the nation's progress.

 

Total water Storage at Elevation	84.73 metres (278.0 ft.)
Maximum Water Surface Elevation	Concrete lined, Rock founded, Six twin
Spillway Type	Gated Spillway Structure
Spillway Capacity at Elevation Drainage Area	34,000 m3/s (1,200,000 cu ft/s)
Drainage Area	6500 sq km
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

• Unit output -173.1MW (222000hp) (Retrotted Units)
• Head (Max) -68.88m (226ft)
• Synchronous speed - 115.4 Rev/Min
• Type of Turbine -Francis, Vertical shaft
• Manufacturer -VA Tech, Voest Alpine, Austria

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)
Maximum Water Surface Elevation	Concrete lined, Rock founded, Six twin

Funding
Financial Support:

International Bank for Reconstruction & Development	$ 47,000,000
United Kingdom Government	$ 14,000,000
Export & Import (Exim) Bank	$ 10,000,000
United States (US) Aid	$ 27,000,000
Ghana Government	$ 98,000,000
Total Cost of Project (at the time of project completion)	$196,000,000