Lac de Grand Maison is a lake in Isère, France. At an elevation of 1698 m, its surface area is 2.19 km2. It is created by the Grand'Maison Dam (constructed between 1978 and 1985) and serves as the upper reservoir in a pumped-storage hydroelectric scheme.

Lac de Grand Maison
Lac de Grand Maison is located in France
Lac de Grand Maison
Lac de Grand Maison
LocationIsère
Coordinates45°12′20″N 6°7′30″E / 45.20556°N 6.12500°E / 45.20556; 6.12500
Typeartificial
Primary inflowsEau d'Olle
Basin countriesFrance
Surface area2.19 km2 (0.85 sq mi)
Max. depth90 m (300 ft)
Surface elevation1,698 m (5,571 ft)