Barrage du Chambon

Historic site and monument

38142 Le Freney-d'Oisans

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, cristallin schist in the soil provided a perfect seal for the water. The potential of hydroelectricity drew the attention of speculators during the 1920s stock exchange boom. Despite having to flood the villages of Le Chambon,Le Dauphine and Pariset, work began on the dam.
During the construction period, a temporary cable car was set up over a 10.5 km stretch from Bourg d'Oisans to Le Chambon to supply the site with cement and other materials more rapidly. This cable car had 193 huge buckets that could each carry 250 km of cement. 62 metal pylons were built 900 m apart, some up to 40 m high, to bear the weight of the 22.5 km steel cable.
The reservoir filled with water between 24 April and 9 October 1935. As early as May 1935, the turbines of the Sainte-Guilherme power plant were being driven by water and intake from the neighbouring Ferrand Valley was later added to boost the supply of water.