The Poitiers administrative court ruled that these so-called replacement reserves were “oversized” and unsuitable “for the effects of climate change”.
Two projects that fell through. The administrative court of Poitiers (Vienna) canceled, Tuesday October 3, the construction and operation in Poitou-Charentes of two sets of projects of fifteen water reservoirs in total. Intended for agricultural irrigation, these installations are nicknamed “mega-basins” by their opponents who denounce a monopolization of the resource.
Created by operators to store the essential needs of agriculture and livestock, these artificial reservoirs, which are multiplying in France while the country is experiencing episodes of drought aggravated by global warming, operate thanks to the withdrawal of water. water in groundwater in winter from November to March – in order to reduce withdrawals from this same groundwater during extreme heat – to make it available to irrigating farmers in summer, when the resource is lacking.
Justice thus vetoed the 2021 prefectural decrees authorizing these two projects for huge open-air basins. The fifteen so-called “substitution” reserves were intended to store around three million cubic meters of water. The administrative court of Poitiers judges that these projects were “oversized” and unsuitable “the effects of climate change”. Franceinfo takes stock of this court decision.
1What projects are involved?
The dispute concerned the creation of water reservoirs in the former Poitou-Charentes region. The first project, on the Aume and Couture basins, in the departments of Charente, Charente-Maritime and Deux-Sèvres, had nine “mega-basins” – farmers and the administration prefer the term “substitution reserves” “. They were to make it possible to store a total volume of 1.64 million cubic meters of water.
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The second project, in the Pallu sub-basin in the Vienne department, provided for six other reservoirs for a total volume of 1.48 million cubic meters of water, according to the decision of the administrative court of Poitiers, which cites the prefectural decree.
2Does this decision concern the “mega-basin” of Sainte-Soline?
No, the decision of the Poitiers administrative court does not concern Sainte-Soline (Deux-Sèvres), where gatherings organized on October 29, 2022 and March 25, 2023 gave rise to violent clashes with the police. The project of 16 “mega-basins” in the Marais Poitevin region, to which the Sainte-Soline installation is attached, was not covered by the appeal filed by several organizations, such as local environmental defense associations. , but also the local branch of UFC Que-choisir and the Bird Protection League (LPO).
3Why did the courts cancel these projects?
The administrative court of Poitiers judges that these “mega-basins” are unsuitable “the effects of climate change”. “In both cases, the court found that the projects were oversized”, conclude the judges in their decision. While these reservoirs must draw water from groundwater in winter in preparation for summer, where water resources are rarer, the court judges “the substitution logic was not actually respected“. He notes that “the calculation of the volume of projected reserves was based on old data, dating from the early 2000s, which no longer reflected the level of withdrawals actually taken in summer for around fifteen years”.
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Concerning the six water reservoirs in the Pallu sub-basin, the judges also underline the “oversizing” of the project. They believe that “the prefect of Vienne had, by authorizing this project, tainted her order with a manifest error of assessment in the implementation of the principle of balanced and sustainable management of water resources”.
Of the nine water reservoirs envisaged in the Aume and Couture basins, the court considers that “the project is not associated with real water saving measures”. The judges also mention “several irregularities in the composition of the file in respect of which the authorization was issued”.
4How did the different actors react?
The associations behind the appeals say they “satisfied with the judgments handed down”. They “put a stop to the disinformation campaign which, for years, has presented megabasins as a means of reducing withdrawals”, they judge in a press release. This court decision is a “great relief” And “very good news for all those who fight for water and against ‘mega-basins'”, Julien Le Guet, spokesperson for the “Bassines non merci” collective, told AFP.
In a press release, the Vienne prefecture considers that the reasons given by the court “question” and announced that it would appeal this decision. Bertrand Lamarche, president of the Pallu water management cooperative society, declared to the daily newspaper The New Republic that irrigators in the area would also do “certainly” call.
5What happens next?
“The annulment of the two decrees has the effect of preventing the realization of the reservations concerned”, specifies the administrative court of Poitiers in its decision. Thus, the projects are at a standstill, even if the various stakeholders will appeal this decision. But these remedies “do not, however, have a suspensive character”, which means that any work could not take place during the procedure. This administrative decision is not a first. While many projects are the subject of appeals, “mega-basins” projects in Charente-Maritime were rejected in February 2023 by the Council of State and the Administrative Court of Appeal of Bordeaux.