Launch of major works to restore some of the naturalness of the Rhône

The project, co-financed by the Compagnie nationale du Rhône (CNR) and the Regional Water Agency, extends over around ten kilometers south of Lyon and should last three years.

This is "the most important ecological restoration ever undertaken for a river in France", declared to the press Mathieu Stortz, general director of the CNR, a general interest company with a concession on the Rhône.

"A river is not just flowing water, it is an ecosystem in constant evolution. We must restore the Rhône's dynamics," added Nicolas Chantepie, deputy director of the Rhône-Mediterranean-Corsica Water Agency.

This operation aims to recreate branches of the river, uproot invasive plants and replant 5.400 trees and shrubs, in order to allow the Rhône to find passageways blocked over centuries of human intervention.

This program will notably dismantle "the Girardon groins and lockers", rock constructions designed at the end of the 19th century by chief engineer Henri Girardon to tame the course of the river. Gradually covered by vegetation, these rock structures have narrowed the river bed.

More than 80.000 m3 of rockfill will be removed, the depth of several channels will be increased to restore the bed of the Rhône, the most artificial river in France with its 19 dams.

The CNR estimates that this restoration of the banks will eventually allow the return to the river of more than 200.000 m3 of fine sand and silt sediments through the action of the current and floods. This should allow the return of diverse vegetation and many species, such as the beaver or the kingfisher, but also fish such as the pike or the bleak.

"This operation is the most significant in the history of the restoration of the river," according to Mr. Stortz. Since 2000, the CNR has already restored 77 lônes (secondary arms or meanders of the river) and 120 kilometers of banks.