Lake Volta in western Africa is known as the largest human-made lake in the world - by area as well as by volume. It covers 8502 km2 or 3.6% of Ghana's area and has a maximum length of 520 km from its northernmost point at the town of Yapei downstream to the Akosombo dam. The volume of Lake Volta is 148 km3. When the reservoir was formed in 1965 about 78 000 people in 740 villages were relocated to new townships, along with 200 000 animals belonging to them. The reservoir is a major fishing area and provides irrigation for farmlands in the Accra plains. It is also important for transportation - generally by ferries and cargo boats. The Ako-sombo Dam controls the reservoir and is 660 m long at crest and 114 m high from crest to base. Its hydropower station produces electricity for much of the Ghana nation.
Although the Akosombo Dam is impounding the world's largest reservoir, it is not the largest dam in the world. The Three Gorges Dam - a dam which is 2309 m long and 185 m high but with a reservoir that is considerably smaller than Lake Volta - holds this position. Upon completion, the Three Gorges Dam will flood 632 km2 of land to create a reservoir about 644 km long and 112 km wide and with a live capacity of 39 km3 of water. The dam will have the largest hydroelectric capacity of the world's dams, reaching 18 200 MW, thus surpassing the former record holder, the Itaipu dam on the Upper Parana River at the Brazil-Paraguay border, by more than 6000 MW. Although the reservoir surface area will reach only 1080 km2, the entire Three Gorges Reservoir area covers 58 000 km2, an area 16 710 km2 larger than Switzerland. Consequently, several dozens to more than 100 mountain tops may become modern landbridge islands in this reservoir landscape.
The highest dam in the world, Nurek on the Vakhsh River in Tajikistan, is 300 m high. Its reservoir stores water for irrigation and hydropower generation. A yet higher dam, Rogun, on the same river has been under construction since 1976 and will be 335 m high upon completion. It is possible to get an idea of the size of these dams by comparing them to the Eiffel Tower in Paris, which has a height from the ground to the tip of the aerial of 324 m.
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