Lac du Verney, Reservoir in Vaujany, Isère, France

Lac du Verney is a large body of water in a mountain region, positioned at 725 meters altitude between the Belledonne and Grandes Rousses mountains. A dam constructed between 1979 and 1984 forms its boundary and operates as part of a hydroelectric power facility.

The area was shaped by human effort when a dam was built between 1979 and 1984 to create the hydroelectric facility. This project enabled electricity generation through water power in this mountain region.

Since 2006 the lake has hosted the opening swim of the Alpe d'Huez Triathlon, held each summer. Windsurfing, canoeing, Optimist dinghies and pedal boats are allowed under lifeguard supervision, while swimming, diving, motorboating and water skiing are banned. The lake lies between the Belledonne and Grandes Rousses massifs, near Allemond, Oz-en-Oisans and Vaujany.

The site is open year-round with no admission charge, and visitors can walk along the shores, have picnics, or explore the surroundings while swimming is not permitted. Parking is available and access is straightforward, with nearby villages offering small shops and rest areas.

The lake is the lower reservoir of the Grand'Maison Dam pumped-storage scheme, so its water level shifts with the plant's operation. Since 2006 it has hosted the opening swim of the Alpe d'Huez Triathlon, held each summer in the valley between the Belledonne and Grandes Rousses ranges.