The reservoir withheld by the dam, Lac de Grand Maison, has a storage capacity of 140,000,000 m3 (113,500 acre⋅ft).

The power generation process begins with water stored in its reservoir at an altitude of 1,698 m (5,571 ft).

It is located on the rear bank of Lac du Verney at 45°08′43″N 06°03′03″E / 45.14528°N 6.05083°E / 45.14528; 6.05083 (Grand'Maison Power Plant) which lies at an elevation of 770 m (2,526 ft).

On the above-ground level, there are four 150 MW Pelton turbine-generators which are used for normal conventional hydroelectric power generation.

After electricity is generated, the water is discharged into Lac du Verney, the lower reservoir.