The dam, built in the late 1950s, rises on the border between Italy and Switzerland at more than 2,000 metres above sea level.

The Val di Lei Dam is located in Switzerland in the municipality of Ferrera (Farera), in the Canton of Grisons. Its artificial reservoir is fed by one of the affluents of the Rhine, which lies inside the Italian territory.

The dam is a double-curvature arch-gravity dam and has a crest lenght of 690 m, the biggest in the world at the time of its construction. It is 141 m high and creates a reservoir of 197,000,000 m3 of water.

The materials needed for the works, including 1,200 tonnes of cement per day, were transported from the valley to the construction site using a cable car system capable of covering a distance of 14 km.

The Val di Lei dam is part of the Hinterrhein hydroelectric complex (Alto Reno Posteriore), an integrated system producing 1,325,000,000 kWh of energy per year, through a group of three power stations.

Works started on 1957 and finished just three years later, far ahead of schedule.

Client: Kraftwerke Hinterrhein A.G. – K.R.R. – Thusis