An earth and rockfill dam
To construct the Grand’Maison earth and reckfill dam, materials were sourced locally, from three earth and a rock quarry which were rehabilitated afterwards.
The Grand’Maison dam is an earth and rockfill dam like the Mont Cenis and Serre-Ppnson dams. It is classed as a “large dam” - a category that is defined by law as dams which are more than 20 metres high with a storage capacity of more than 15 million cubic metres.
Construction took ten years (from 1976 to 1987) on account of the size of the structure and the quality requirements which meant that rigorous logistics and organization had to be put in place.
Great care was taken with regard to the selection of materials, which were monitored throughout the works (water content, level of compaction) in an on-site laboratory.
In view of the volume of the structure, materials were sourced locally, from three earth and a rock quarry. This reduced lorry transportation costs. A conveyor belt with a bridge to cross the ravine was built to take earth from the La Cochette deposit
After the termination of works the quarries were rehabilitated; some were turned into lakes and others were landscaped and grassed over or planted with local species. The landscape was thus returned to its initial condition.