The Serre-Ponçon dam history

The Durance, once considered as an unpredictable and devastating river rises out of the mountainside, on the shady side of Montgenèvre, and flows into the Rhone, south of Avignon.

Men feared its devastating floods that destroyed infrastructure, fields and even homes. In 1843 and 1856 it caused the most damage.

The valley offers privileged farming and settlement sites. Most inhabitants live on agriculture and livestock. The DURANCE allows crop irrigation. Its speed ranges from 18 to 1800 m3/s.

This river was also a transportation route for the timber trade from the middle Ages to the last quarter of the nineteenth century. Tree trunks were felled in the forests, and then the logs were tied by strings made of plant fibers to form rafts.

Craftsmen called “radeliers”, built these skiffs and drove them from St. Clement on Durance down to the Rhone.

Generating electricity and providing a water reservoir

The dam was built initially to generate electricity. After the Second World War, the need for electricity increased. It was also a matter of constructing a water reservoir for agriculture and mastering the devastating Durance.

The idea of a dam on the Durance dates back to 1856. In 1912 Ivan WILHELM, Roads and Bridges engineer originally from Alsace, published a book in which he demonstrates the needs of regulating the course of the river. In addition, a dam would constitute a giant water tank for agriculture.

After many studies, it appears that at Serre-Ponçon, one cannot build a concrete dam because the bedrock is buried under 110 meters of alluvium.

EDF decided to build an earth dam inspired by American techniques because this type of construction is more tolerant of deformations caused by earthquakes.

VAN WILHELM who designed the dam died in 1951. He therefore never saw its completion because the construction work began in 1955. His dam project was approved by the Technical Committee for Large Dams.