Clearing a river bed

10 November 2017 - Projects update and handover - France

In Normandy, teams from VINCI Construction Terrassement – as leader of the VINCI joint venture –, VINCI Construction Maritime et Fluvial and TPC (VINCI Construction France subsidiaries) and ALZEO Environnement are clearing the bed of a 13 km stretch of the Sélune (a coastal river flowing into the bay of Mont Saint-Michel) in the reservoir area upstream from the Vezins hydroelectric dam, built in 1931.

The aim is to extract, store and relocate in situ 450,000 cu. metres of sediments that have accumulated in the reservoir area, a small proportion of which contains heavy metals.

The environmental challenge is to prevent particles in suspension from polluting the river during the associated emptying of the dam in order to allow a safety inspection to be carried out. Following this inspection, the public authorities will decide on the dam’s future, whether it will be renovated or dismantled, with the renaturation of the valley.