The Bosdapous is a small, 4.5 km long river surrounded by a watershed mainly made up of forest. It’s a well-preserved tributary of the Gave d’Aspe River and rises to an altitude of 900m. Its good water quality hosts a population of brown trout, European eel and white-clawed crayfish. This stream has a very important role for these species, which are also present in the Gave d’Aspe (the main river in the valley). Trout go there every year to reproduce. The populations of crayfish, which are becoming increasingly rare, also need to be connected to facilitate their resilience to crises.
Many projects have recently been carried out on the main river but not on small tributaries like the Bosdapous, affecting the circulation of fish (and of all aquatic organisms in general). For 20 years, an obstacle located 500m from the confluence with the Gave d’Aspe prevented the circulation of fish and crayfish populations upstream. It was a culvert that allowed passage to an old sheepfold. For these reasons, Federation Peche 64 has been in dialogue with the owner of the Lescoude Culvert, who favoured removing it. Until 2020, the project could not succeed due to financial reasons.
|Km to be opened||4|
|Key habitats||Spawning habitat for salmonids|
|Focal species||Brown trout, European eel and white-clawed crayfish|
|Removal date||October 2022|
|Project type||Dam removal|
The project team removed the culvert and replaced it with a small bridge without influencing the river. This opened 4 km of river and reconnected the Bosdapous to the Gave d’Aspe River. Trout spawners will now be able to access the Bosdapous excellent upstream spawnings grounds, and eels will also be able to colonise new territories.