Grimselsee

Artificial lake in the Canton of Bern, Switzerland

46°34′10.52″N 8°19′38.66″E / 46.5695889°N 8.3274056°E / 46.5695889; 8.3274056Typeartificial lake, hydroelectric reservoirPrimary inflowsOberaarbach [de], TreibtenbachPrimary outflowsAareCatchment area74.4 km² (28.7 sq mi)Basin countriesSwitzerlandSurface area2.63 km² (1.02 sq mi)Water volume95 million cubic metres (77,000 acre⋅ft)Surface elevation1,908 m (6,260 ft) Map

The Grimselsee or Lake Grimsel is an artificial lake near the Grimsel Pass in the Canton of Bern, Switzerland. With a volume of 95 mio m³ (20.9 billion imperial gallons, 20.1 billion US gallons), it is larger than other hydroelectric reservoirs in the Aare headwaters region: Oberaarsee, Räterichsbodensee and Gelmersee. The dam was completed in 1932 and is operated by Kraftwerke Oberhasli AG (KWO). It is located in the municipality of Guttannen.