Lake is dammed by two dams

The Grimsel is located in the canton of Bern in the community Guttannen.

The Grimsel is effectively used with a volume of 95 million cubic meters of the largest reservoir in the Grimsel mountain. In the same region even the Oberaarsee, Räterichsbodensee and Gelmersee be stowed. The lake can be reached via the Grimsel Pass, on the west side of the lake is the Unteraargletscher. Sunk in the lake is the old Grimsel Hospice, which was canceled before the flooding up on the ground.


The two dams Seeuferegg ( gravity dam, 42 meters high) and hospital Lamb ( arch dam, 114 feet high ) were completed in 1932.

The power plants Oberhasli AG (KWO ), operator of the reservoirs plans with the project, " KWO plus " among other things, a development of dams. It is expensive with a CHF 260 million expansion will increase the dam of Lake Grimsel by 23 meters and thus increases its volume by 75 million m³. The project is motivated by the fact that at present too high a water supply is to deal with in the summer, which consumes uneconomic today is stored instead.

Due to the higher water level of Lake Grimsel today Grimselstrasse would be flooded over a length of 700 m. The project therefore looks as a substitute for the construction of a cable-stayed bridge. The Grimselsee would thereby crossing of a roadway held with ropes at two 70 m high pylons.

Environmentalists fear that more present in the upper reaches of the lake are flooded Moore of national importance by the extension of Lake Grimsel.

Technical data of the dams

Grimselsee Gallery

Emptied lake

Seen look at the hospital Lamb dam from the visitor center from

View of the Grimsel and the Räterichsbodensee