Barrage du Chambon

The Chambon dam was built between 1929 and 1935. In 1918, the industrialist Henri Frédet discovered the potential of this narrow, 75m long section of the Romanche river. It proved to be the ideal location for regulating the flow of the river.
In 1921, studies showed that the presence of hard crystalline schist in the soil made the water perfectly impermeable. This potential attracted a great deal of attention at a time of stock market speculation on hydroelectricity in the 1920s.

Despite the condemnation of the villages of Chambon, Dauphine and Pariset, work began.
For the duration of the work, a temporary 10.5 km cableway was installed from Bourg-d'Oisans to Le Chambon to transport cement and other materials more quickly. The ropeway consisted of 193 skips, each capable of carrying 250 kg of cement.
62 steel pylons had to be erected, some up to 40 meters high and spaced 900m apart, to support a steel cable 22.5 km long.
Impoundment of the reservoir began on April 24 and was completed on October 9, 1935. By May 1935, the turbines of the Sainte-Guilherme power plant were powered. A water intake in the neighboring Ferrand valley was built to increase the water supply.