This operation is the result of a collective effort involving elected representatives, the state, environmental protection associations and Electricité de France (EDF). Its objective is to reconfigure the Poutès dam to restore sedimentary and piscicultural transparency in Haut Allier, in the Haute-Loire area of the Auvergne-Rhône-Alpes region, while preserving 85 % of the renewable energy production potential of the Monistrol d'Allier hydroelectric plant.
- 19 September 2020
This major project is first and foremost a project for the area designed and implemented with all the stakeholders. It is designed to meet all expectations, both in terms of economic benefits, renewable energy production and environmental impact.
The work is carried out under EDF’s supervision with a view to restoring ecological continuity to the Allier river.
The Poutès dam is listed as a priority project in the 2014-2019 management plan for migratory amphihaline fish in the Loire and Sèvre Niortaise basins and Vendéen coastal basins. The current structure is a major obstacle to the migration of Atlantic salmon from the Allier basin and blocks the return of spawners and the downstream migration of juveniles.
The development of a new dam
The operation consists of dismantling the existing 18-metre high dam to build a new 7-metre high dam. This will make it possible to go from a 3 500-metre-long containment to just 400 metres, equipped with mobile gates for sediment transit and the passage of fish.
The gates will be open for three months a year in order to completely eliminate the reservoir, so as to allow for the entirely free movement of fish during the migration phases, as well as sediments. An additional fish crossing system will be set up by modifying the existing lift, which will be modernised and simplified to improve its efficiency. A drop-down flap on the left bank will complete the system.
The major challenge is to give salmon spawners access once again to the most productive spawning grounds in the upper Allier basin thanks to favourable ecological conditions. Indeed, these spawning grounds have great potential for hosting salmon spawners thanks to supports for their eggs, favourable habitats and water temperature adequate for their survival as well as their fry.
A concerted and jointly constructed operation
Thanks to its technical operation and partnership-based development, the new Poutès dam is a flagship industrial project that embodies the values of the Sustainable Hydropower Agreement signed in June 2010 by all stakeholders, and in the spirit of the Grenelle Environment Forum.
The dam will benefit the area, the aquatic environment and biodiversity. Moreover, it takes a new approach to sustainable hydropower. The new Poutès dam demonstrates that it is possible to reach optimal compromises between the challenges of biodiversity and energy, despite the initial conflict that for a long time came between the various parties.
From now on, the project is guided by a desire for concerted partnership construction between all the stakeholders, whether involving development of technical choices, enhancement of the area or even communication on the project. This innovative approach will make it a model for an ambitious and shared industrial project.
Total investment and European funding
The ‘Reconfiguration of the Poutès dam’ project received a total investment of EUR 17 300 000, with the European Regional Development Fund’s contribution amounting to EUR 558 302 through the ‘ERDF interregional operational programme for the Loire’ cooperation programme for the 2014‑2020 programming period. The investment falls under the ‘Jobs, Growth and Investment’ priority.