At Locquirec’s Moulin de la Rive, the old aqueduct and undersized culvert on the Lapic blocked fish migration and sediment transport and created a drop that proved impassable, despite the site being a priority action zone for eel and sea trout. Rescue electrofishing during works confirmed the barrier effect, with far fewer eels and trout upstream than downstream. The project replaced the structure with a 20 m precast frame bridge set 60 cm lower than the former invert, restored a more natural bed with stone and blocks, and added a concrete control wall at the inlet so that high flows can safely spill into the upstream wetland reedbed. The design also integrates a faunal shelf for mammals and bat roosting blocks under the deck, and it secured vulnerable sewer lines that lay near the channel bed. Implementation required careful coordination around numerous underground utilities and a tight spring window to avoid the summer tourism season, combined with strong, proactive communication with residents, surfers and local associations. Traffic on RD64 was diverted from 17 March, and the route reopened ahead of schedule on 30 April 2025. Funding came from Agence de l’Eau Loire-Bretagne, Région Bretagne and Morlaix Communauté. Early observations show fish passage working, otter prints upstream and downstream, macrophyte recovery and rapid revegetation of disturbed zones. The project contributes to WFD ecological continuity targets in a basin facing multiple pressures, including agricultural pollution, hydrocarbons from runoff and intensive anthropogenic footprint.