Mauvoisin Dam is a concrete variable radius

arch dam An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthe ...

across the

Val de Bagnes Val de Bagnes, also called the Vallée de Bagnes (German: Bangital or Baniental) is a valley located in the Entremont District in the Canton of Valais of Switzerland. Geography Val de Bagnes is traversed by the Drance de Bagnes. In the upper pa ...

on the Dranse de Bagnes stream, in the canton of

Valais Valais ( , , ; frp, Valês; german: Wallis ), more formally the Canton of Valais,; german: Kanton Wallis; in other official Swiss languages outside Valais: it, (Canton) Vallese ; rm, (Chantun) Vallais. is one of the cantons of Switzerland, 26 ...

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

. Initial construction on the dam commenced in 1951 and was completed in 1957, with the reservoir filling by 1958. In 1991, the dam was raised to increase the capacity of the reservoir for winter storage. The dam's primary purpose is

hydroelectric power Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

generation. The eighth highest dam in the world, Mauvoisin stands high and long, with a structural volume of . The impounded water behind the dam forms the

Lac de Mauvoisin __NOTOC__ Lac de Mauvoisin is a reservoir in the canton of Valais, Switzerland. The reservoir is formed by the Mauvoisin Dam, which is high. The dam is the 11th highest in the world, and the 6th highest arch dam. It was built in 1951–1957, and ...

, which has a capacity of 211.5 million m³ (171,500 acre feet) and a full surface area of . The dam and reservoir control runoff from a catchment of . Flood waters are released by a gated spillway with a capacity of . Water from the dam is fed to two hydroelectric power stations with a combined capacity of 363

megawatt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units, International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), ...

s (MW). Mauvoisin Dam provides a

hydraulic head Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22. It is usually measured as a liquid surface elevation, expressed in units of length, ...

of to the Fionnay generating station, which can produce 138 MW from three

Francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The proces ...

s. The water then drops another to the Riddes generating station, where it drives five

Pelton turbine The Pelton wheel or Pelton Turbine is an impulse-type water turbine invented by American inventor Lester Allan Pelton in the 1870s. The Pelton wheel extracts energy from the impulse of moving water, as opposed to water's dead weight like the trad ...

s with a combined capacity of 225 MW. The two plants produce about 943 million

kilowatt hour A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 megajoules (MJ). Kilowatt-hours are a common bil ...

s (KWh) each year, with Fionnay generating 278 million KWh (29.5%) and Riddes generating 665 million KWh (70.5%). Mauvoisin Dam also serves for flood prevention and sediment control. The dam helps protect the Bagnes and

Rhône The Rhône ( , ; wae, Rotten ; frp, Rôno ; oc, Ròse ) is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and southeastern France before discharging into the Mediterranean Sea. At Ar ...

river valleys from

glacial lake outburst flood A glacial lake outburst flood (GLOF) is a type of outburst flood caused by the failure of a dam containing a glacial lake. An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier, is called a jö ...

s such as ones that occurred in 1595 and 1818. During the 1960s and 1970s,

Giétro Glacier The Giétro Glacier or Giétroz Glacier (french: Glacier du Giétro) is a 4 km long valley glacier located in south-western Switzerland. The 1818 Giétro Glacier catastrophe, which led to lake outburst flood, is one of the most famous and mo ...

adjacent to Lac de Mauvoisin threatened to produce icefalls, which could have overtopped the dam. Giétro has retreated since 1980, eliminating the threat of such an event. The dam also traps about of sediment each year, helping to extend the life of downstream hydroelectric plants. However, sediment accumulation also poses a threat to the dam's useful life; a project to remove sediment has been proposed but has not been implemented because of safety concerns. In 2016, the dam was the location of the world-record highest successful basketball shot. 28-year-old

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

n Derek Herron (from the YouTube channel How Ridiculous) launched a basketball from the top of the dam, where it fell 180 metres directly into a net placed on the ground below.

References

{{Reflist, 30em

External links

Cross section of Mauvoisin Dam (in French)
Mauvoisin Dams completed in 1957 Dams in Switzerland Bagnes

See also

References

External links