The Sibila ford will be transformed to restore ecological continuity on the Daronne River and its connection with the Doux River.
The Sibila ford is a submersible road structure owned by the municipality, comprising 11 concrete nozzles, and it poses a significant problem for sedimentary and ecological continuity, particularly for fish. During high flow events, sediment clogs the nozzles, further limiting water and organism passage. Fish migration is hindered by the height of the downstream drop created by scouring, as well as by the length (6 m) and flow conditions within the nozzles.
The structure is located on the Daronne River, approximately 100 m upstream from its confluence with the Doux in Ardèche. The Daronne is a main tributary of the Doux, yet this barrier disrupts connectivity between the two rivers. An inventory of ecological continuity carried out across the Doux catchment identified and prioritised barriers. The Sibila ford is considered a priority obstacle due to its location, characteristics and associated environmental issues.
This project is a follow on from a previous pre-demolition grant from the programme.
| Project status | Live |
|---|---|
| Project type | Dam removal: demolition |
| Country | France |
| River | Daronne |
| Removal timeline | July - September 2026 |
| Km to be opened | 2 km |
| Focal species | Brown trout (Salmo trutta), European eel, beavers, otters |
| Organisation | SYNDICAT MIXTE DU BASSIN VERSANT DU DOUX & European Rivers Network |
| Website | European Rivers Network & Rivière Doux |
The Daronne is classified as a first category fish river, mainly inhabited by salmonid species. In this river, the most relevant species are the European eel and the brown trout. The structure is identified in the Eel Management Plan for the Rhône-Méditerranée basin and currently prevents fish migration along the Daronne, as well as exchanges between the Doux and the Daronne. Eels are present at the Doux-Rhône confluence, highlighting the importance of restoring connectivity.
The Daronne is also listed in the SDAGE as a biological reservoir, meaning it plays a key role in supporting trout life stages such as reproduction, feeding and growth. Fragmentation of this river therefore has negative impacts on fish populations across the wider Doux catchment.
The project aims to restore ecological and sediment continuity by modifying the Sibila ford. The structure currently blocks the movement of aquatic and semi-aquatic fauna, including beavers and otters, which are forced to bypass the crossing and face increased collision risk with vehicles.
In addition, the ford causes sediment accumulation upstream, altering the natural riverbed slope. It also creates a ponding effect, leading to increased water temperatures. This negatively affects sensitive species such as brown trout, minnows and blageon, favouring more tolerant species and contributing to a decline in ecological quality. Warmer water also increases the risk of eutrophication and associated mortality of aquatic life.
The expected outcome is improved habitat conditions, restored species movement, and a re-establishment of more natural river processes along this section of the Daronne.
Funded by
