Oberhasli - power stations

The Oberhasli hydro-electric scheme (1925-54) comprises four separate power stations. The Handegg I station (90,000 kW), built in 1925-32, uses the water of the Grimselsee (100million cu.m/3,531million cu.ft), formed by the Seeuferegg and Spitallamm dams, which is carried in a 5km/3mi-long tunnel to a subsidiary reservoir, the Gelmersee (13million cu.m/459million cu.ft) and the power station 540 m/1,772ft below. The Innertkirchen station (192,000 kW) uses water from Handegg I, which is conveyed to it in a tunnel 10km/6mi long. The Handegg II station (60,000 kW), built in 1947-50, obtains its water from the Räterichsboden lake (27million cu.m/953million cu.ft) and the small Gauli reservoir in the Upper Urbach valley. The power station (underground) is at Handegg.

The Oberaar station (31,000 kW), built in 1950-54, uses water from the Oberaarsee, formed by a dam 525 m/1,723ft long and 105 m/345ft high; the underground power station is between the Grimselsee and Räterichsboden. An expansion of the power station is planned for the 1990s, with the construction of a new dam.