After several restoration projects in recent years, this latest phase of work will restore the Poyat all the way back to its source.
The Poyat stream is a left-bank tributary of the Ruisseau de Fonbonne, which in turn lies in the catchment area of the Loise, a right-bank tributary of the Loire River. The catchment area of the Poyat is very small: around 5 km² for approximately 3 kilometres of watercourse. It has high potential for aquatic life: Salmo trutta, Cottus gobio, and Lampetra planeri have been recorded.
This sector (stream basin of the Fontbonne stream) is home to the white-clawed crayfish (Austropotamobius pallipes, classified as endangered by the IUCN). These populations are exceptional in the department. Restoration work has already been carried out downstream of the Poyat stream to restore habitats favourable to the species and enable the stream to recolonise.
| Project status | Completed |
|---|---|
| Project type | Dam removal: demolition |
| Country | France |
| River | La Poyat |
| Removal date | September - December 2024 |
| Km opened | 2.2 km |
| Focal species | Salmo trutta, Austropotamobius pallipes, Cottus gobio, Lampetra planeri |
| Organisation | European Rivers Network & SISMAE |
| Website | European Rivers Network & SISMAE |
Until now, the Poyat watercourse has been perched on the western slope with a straight course, partitioned by two impassable structures. These two structures are the last upstream barriers along the Poyat’s main course. The removal of these barriers will allow the watercourse to be restored up to its source. After this new removal, the river will be completely unfragmented.
For years, several restoration projects have already been carried out in the Fontbonne and downstream of the Poyat stream to restore habitats favourable to species and allow the stream to be recolonised (including the removal of a pond and hydro-morphological restoration of the watercourse, a culvert restoration project for ecological continuity, and the restoration of banks using plant techniques and fencing).
The removal of the two structures will reopen the watercourse up to its source, potentially enabling the Poyat to be recolonised by the white-clawed crayfish (Austropotamobius pallipes). The Poyat has relatively sustained low water flows, making it a significant refuge area in summer.
The project also involves restoring the watercourse to its original talweg, thereby improving the dynamics of alternating flow facies and increasing and enhancing fish habitats. This will also reconnect the stream to the low-lying wetland present on site, boosting local hydrology, particularly during periods of severe low water levels. The installation of fencing will limit the impact of cattle trampling.
The removal of the barriers and the restoration of the watercourse have significantly improved the ecological health of the area. The re-established watercourse now supports a more natural hydromorphological function, with improved flow variability, stable bed conditions, and reduced erosion risks. Fish and sediment continuity are now assured, supporting the recovery of migratory species and fostering a healthier aquatic ecosystem. Overall, the project has contributed to the long-term resilience of La Poyat reinforcing its ecological integrity and sustainability.
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