The River Bruche, a major tributary of the River Ill, before it runs into the Rhine, has aquatic habitats that have been recognised as being especially favourable for the reproduction of major, migratory diadromous species (such as the Atlantic salmon, the marine lamprey and the sea trout). However, access to spawning grounds for these species is made almost impossible owing to the presence of three major hydraulic structures that seal off the entire river basin. In view of this situation, in 2000 the Molsheim-Mutzig joint committee for local authorities undertook an ambitious project to restore continuity for fish breeding.
The Molsheim, Mutzig and Avolsheim-Wolxheim dams were therefore fitted with fish passes, the most iconic of these being the artificial bypass river on the Avolsheim dam (completed in 2010).
Creating a bypass river was the most suitable solution for this site. It runs for 135 metres with a succession of 18 weirs consisting of linked rip-raps. Support walls and rock armour have been installed to consolidate the banks along the bypass river.
Total investment in this project was 230,900 euros.
ARTELIA VILLE ET TRANSPORT
AGENCE DE STRASBOURG 15 avenue de l'Europe 67300 Schiltigheim
Players involved and their roles
CC DE LA REGION MOLSHEIM - MUTZIG
CONSEIL GENERAL, AERM, FEDERATION DE PECHE, ASSOCIATION SAUMON RHIN, COMITE DE GESTION DU BASSIN BRUCHE-MOSSIG, ONEMA