Map of aquifer levels in mainland France on 15 July 2025.
© BRGM
Trends observed on piezometers on 15 July 2025.
© BRGM
Trends
90% of levels were down at 15 July 2025, compared with 87% at end-June.
Summer rainfall adds little water to the aquifers. The infiltration of rainwater moistens the soil and is mostly taken up by vegetation.
Note that levels remain stable in the alluvial aquifers and tertiary formations of the Bas-Rhône and Durance rivers. In this sector, the aquifers are recharged by the excess from irrigation. This recharging process is essential for ecosystems and also for groundwater abstraction, particularly for drinking water.
Situation observed on piezometers on 15 July 2025.
© BRGM
Aquifer situation
The situation continued to deteriorate between the reports of 1 July and 15 July. This deterioration is visible in the aquifers along the Languedoc coastline, which are intensively exploited for tourism (drinking water and leisure activities), as well as in the aquifers in the north-eastern part of the Massif Central. Improvements can be seen only in a few areas that have received rainfall in the past 30 days and where the aquifers are highly reactive: the Cotentin to Mayenne basement, the Jurassic limestone aquifers of the Causses du Quercy and Corsica.
The groundwater situation continues to vary, depending on the rainfall in recent months and the reactivity of the aquifer:
- above or close to normal for inertial aquifers (Paris Basin, Rhône-Saône corridor);
- below normal for reactive aquifers and less inertial aquifers (Artois coastline and eastern edge of the Paris Basin) in the northern two-thirds of the country;
- more satisfactory for the reactive aquifers in the south and Corsica.
Aquifer levels in the Roussillon region and Corbières Massif remain low to very low, and are continuing to cause concern. Levels are also becoming low in the alluvial aquifers of the Aude département.
Forecasts
Depletion is expected to continue throughout the summer, unless significant accumulated rainfall is received in areas that have reactive aquifers.
Given the favourable situation of the inertial water tables of the Paris Basin and eastern Lyon area, levels there are likely to remain above normal during the summer.
In contrast, forecasts are highly pessimistic for the aquifers of the Roussillon plain.
They also remain uncertain for other aquifers: generally pessimistic for the reactive aquifers in northern and central France and optimistic for those in the south (except in the Pyrénées-Orientales and Aude départements).
Groundwater situation: a new map and more frequent bulletins
The BRGM groundwater status report, which is eagerly awaited by the public every month, is being revamped. It will now be published twice a month, and the map will have a new colour scheme to make it easier to read.
As of 1 July 2025, the comparative map between the current month and the same month of the previous year will also be reissued with the new colour scheme.
Map drawn up by BRGM on 17 July 2025, based on data acquired up to 15 July 2025.
Data source: ADES database (ades.eaufrance.fr) / Hydroportail (hydro.eaufrance.fr) / Background map © IGN. Data producers and contributors: APRONA, BRGM, Conseil Départemental de la Vendée, Conseil Départemental des Landes, Conseil Départemental du Lot, EPTB Vistre Vistrenque, Parc Naturel Régional des Grandes Causses, Syndicat Mixte d'Etudes et de Travaux de l'Astien (SMETA), Syndicat Mixte pour la protection et la gestion des nappes souterraines de la plaine du Roussillon (SMNPR).
This map shows the global indicators reflecting the average fluctuations of the aquifers. They are based on point indicators collected at groundwater monitoring points (by means of piezometers).
The "Aquifer levels" indicator compares the current month’s figures with those of the same months in the entire record, i.e. at least 15 years of data and sometimes up to as much as 100 years of data. It is divided into 7 classes, from the lowest level (in red) to the highest (in dark blue).
The grey areas correspond to areas without unconfined aquifers, i.e. with an impermeable or semi-permeable layer above the aquifer, and/or sectors with a very low density of measuring points. This last case primarily concerns mountainous areas with small, heterogeneous aquifers.
The "Evolution of levels" indicator reflects the variation of the water level of the past month compared to the two previous months (stable, increasing or decreasing).
These global indicators reflect general situations and trends and do not take into account possible local disparities.