The Cignana dams are located over 2,000 meters above sea level. Until 1983, they were also used as a storage reservoir for the pumping station existing in that time between the Perrères weir and the dams, through the diversion channel and the forebay reservoir of the Perrères waterfall of the Maën hydroelectric plant, with the Promoron pump station.

This still exists today, out of service, in the building above the forebay reservoir. The electricity needed for pumping was supplied through 6 kV cables placed alongside the penstock, directly from Maën’s alternator busbars.

The main dam is one of the first dams made of concrete. In contrast, the secondary dam is smaller in size than the first one. In 1989, the face of the two dams was covered with PVC sheeting and protected from winter ice by insufflating small amounts of air at the base, which rising to the surface creates a water movement that prevents, for a few meters in front of the face, the formation of ice.

Both the out-of-service Promoron pumping station and the Cignana dams are among the routes of the Energy Tours.

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