Four megabasins in Poitou, including Sainte-Soline, declared illegal by the court

The Bordeaux Administrative Court of Appeal delivered its verdict this Wednesday, December 18, annulling the authorizations for four irrigation reservoirs in Poitou, including the highly contested megabasin of Sainte-Soline (Deux-Sèvres). These structures, deemed illegal, jeopardize the survival of a protected species, the little bustard, by partially or entirely destroying its natural habitat.

A decision that intensifies tensions

These megabasins are part of a broader project of 16 water reservoirs designed for agricultural use in the Marais poitevin, a project fiercely opposed by a dozen environmental organizations. Opponents, including Nature Environnement 17, the League for the Protection of Birds, and several fishermen’s federations, had challenged the authorizations granted by the State. The Sainte-Soline reservoir, in particular, has become a symbol of this struggle, with protests occasionally turning violent, notably in March 2023.

According to the court, the four concerned basins, including Sainte-Soline, require a specific derogation for protected species, which was not obtained. As a result, the court suspended both construction and future water filling of these facilities, pending possible regularization.

Stored water remains usable but cannot be refilled

The Sainte-Soline reservoir, the only one of the four already constructed, will still allow its stored water to be used this summer by connected farmers, as specified in the court’s decision. However, no new filling will be authorized.

Impact on water resource management

The applicant associations also criticized the substitution basin project—filled in winter by pumping groundwater for summer irrigation—for disrupting the balance of water resources. The court, however, rejected this argument, stating that “the administration conditioned the filling level of the reservoirs on compliance with relevant thresholds set with regard to the groundwater level” and that the project adheres to “the principle of balanced and sustainable water management.”

This decision marks a new chapter in a debate interweaving environmental, agricultural, and societal issues, which continues to deeply divide stakeholders.