Will France escape the drought this summer? After two years of significant summer water restrictions, the groundwater tables were, at the end of spring, mostly full, with the notable exception of the Pyrénées-Orientales, a department for which the government is launching an adaptation plan.
As of May 1, 65% of metropolitan water tables were above normal, with 21% whose levels were even very high. Conversely, 22% were below normal, including 4% at very low levels, in Roussillon but also in certain parts of Corsica, announced Wednesday the Geological and Mining Research Bureau (BRGM).
Completely reversed situation compared to 2023 and 2022
The situation is therefore much better than last year at the same time. Indeed, last spring, it was “very worrying” with 68% of water tables below normal, underlines the BRGM. In 2023, two thirds of metropolitan departments were still experiencing a “drought crisis” red alert in October, after a particularly dry summer. The latter leading to significant water restrictions: watering bans for individuals and farmers, prohibited filling of swimming pools, reduced withdrawals for certain industrial uses, etc. In 2022, up to 700 municipalities had been deprived of drinking water.
“The situation has completely reversed due to very excess recharge” particularly during the March/April period when it rained a lot, indicated Violaine Bault, hydrogeologist at BRGM. Unlike the winters of 2022 and 2023, this year was marked by the return of abundant rains to part of the territory, allowing very low water tables to be recharged. In March, the metropolis experienced almost 85% more rain than normal for the season.
April, on the other hand, was more contrasted with certain regions having a lot of rain, such as the northern half and the center-east, while the Provence-Alpes-Côte d’Azur region and Corsica had a deficit in precipitation. In the Pyrénées-Orientales, the rain certainly fell for the first time in more than two years, but it arrived too late and on soils that were too dry to really be able to infiltrate and recharge the water tables. As summer approaches, Roussillon therefore remains in the red regarding drought and is preparing for a third summer of significant restrictions on water use.
As warmer than normal conditions approach?
For the rest of France, the BRGM is “rather optimistic”. Over the first three weeks of May, rain continued to fall in certain regions, delaying the groundwater draining period, which traditionally begins in April. And even if the spring vegetation is now well out, it can benefit from particularly humid soils to obtain a good supply of water and thus draw less from the water tables. Likewise, precipitation promotes natural irrigation of crops, again delaying excessive demand on aquifer reserves at depth.
However, some uncertainties remain for the coming months, tempers the BRGM. Météo-France forecasts until July show a trend towards warmer than normal conditions, which could encourage water evaporation. And for precipitation, it is impossible to predict whether the rains will continue or not.
The situation of certain water tables could therefore suddenly deteriorate. This could particularly be the case for the south-west of the Paris Basin, the south of Alsace, the Puys chain in the Massif Central, the Saône corridor, eastern Lyon or even the west of the Pyrenees.