Lac de Mauvoisin

The Lac de Mauvoisin is a reservoir, which is located at the far end in the Bagnes, in the southwest of the canton of Valais, Switzerland.

The reservoir with an area of ​​2.08 km ² has a length of 4.9 km, an average width of 500 m and is located at 1975 m above sea level. M. in the catchment area of the Dranse de Bagnes. It is located in a deep valley surrounded by high, glaciated peaks of the Valais Alps. West of the lake is the 4314 m high Grand Combin, to the east, the Ruinette rises ( 3875 m above sea level. M. ). The catchment area of ​​Lac de Mauvoisin 114 km ² in size. These include several major glaciers, namely the Glacier du Giétroz, the Glacier du Brenay, the Glacier d' Otemma and the Glacier du Mont Durand.

With a storage capacity of 210 million cubic meters of Lac de Mauvoisin one of the largest reservoirs in Switzerland. The dam of the type arch dam is 250 m high and thus after the dam of Lac des Dix, the second highest in Switzerland. It was originally built in 1957 with a height of 237 m and increased to 1991 by 13.5 m. This makes it the highest in operation arch dam in Europe: the Enguri dam in Georgia ( 271.5 m) is located just outside of Europe and the Vajont Dam in Italy ( 261.6 m) is unused.

It was built in 1951 according to sketches and plans of Albert Maret and under the direction of Alfred Stucky.

In addition to the natural catchment area more tributaries of the Dranse be routed through tunnels into the lake. Operating company is the Forces Motrices Mauvoisin SA.

Passing through a tunnel waters of Lac de Mauvoisin for underground central Fionnay is headed (138 MW), the turbines there and then placed in a balancing reservoir. From this pool, a 15 km long tunnel leads into the Rhone Valley. The water is in the Central Riddes the turbines (225 MW). To the storage system, the system Chanrion (28 MW) are south of Lac de Mauvoisin and the sub power station Champsec (5 MW ) down the valley in the Bagnes. The entire generator output, therefore, makes of 396 MW, the standard capacity is approximately 1,000 GWh annually.