The Orne is a 177 km-long river in Normandy, rising in the Orne département and flowing through the Calvados département before emptying into the English Channel at Ouistreham. The Orne is the second most important river in the Seine-Normandy basin, after the Seine. The Feuguerolles-Bully migratory fish counting station is located on the Orne at the Grand Moulin dam, 33 km from the sea. This dam is the second structure on the Orne from the sea, after the Montalivet dam at Caen. Since the 1980s, migratory fish have been monitored and counted at this site. Firstly, by means of a trapping system, then, from 2010 onwards, with the construction of a new fish pass with successive basins (deemed non-selective compared to slow-moving passes) and the installation of a video-counting system (while retaining a trapping device that can be activated).
Practical information
Places are limited, so reservations are essential. No ticket sales on site on the day of the visit, payment required on reservation.
Ticketing opens on January 14, 2026, online and at tourist information offices in Caen and Ouistreham.
