Map of aquifer levels in mainland France on 15 December 2025.
© BRGM
Trends observed on piezometers on 15 December 2025.
© BRGM
Trends
As of 15 December, recharge is in progress at most groundwater sites, with 58% of them showing rising levels.
Less responsive groundwater bodies show rising levels along the Rhône-Saône corridor and the Artois coastline and declining levels in the Paris Basin and southern Artois. There has been a lack of autumnal rainfall in the Paris Basin, resulting in a sluggish start to the recharge season.
Levels are generally rising at responsive groundwater sites. Declining or stable groundwater trends are noted in Lorraine, the southern Massif Central and Provence, which received little rainfall in November and December. Snowfall contributed little to groundwater recharge in the Alps, and levels are stable in this area.
Situation observed on piezometers on 15 December 2025.
© BRGM
The groundwater situation
The groundwater situation has started to improve from mid-December. Levels are beginning to improve at several responsive groundwater sites, which benefited from rainfall infiltration between late November and early December, including the Boulonnais region, western Armorican Massif, Berry, northeastern Massif Central, Périgord and the Angoulême Basin. In contrast, groundwater sites in Lorraine are experiencing a slight decline.
The current situation at responsive sites is due to the spatial and temporal variability of autumn precipitation, with a succession of dry and wet spells. Rainfall events have thus not been very effective for groundwater recharge. The situation is satisfactory overall, with moderately high to high levels at responsive groundwater sites along a central strip, from Jura to Charentes. Levels are less satisfactory, from close to normal to moderately low, at responsive groundwater bodies in the north of the country (Armorican Massif, Artois and Grand-Est region) and in the south of the country (western Aquitaine Basin, southeastern Corsica). The groundwater levels in the Roussillon and the Corbières Massif remain excessively low.
In the less responsive groundwater bodies of the Sundgau (southern Alsace) and the Rhône-Saône corridor, levels are close to normal to moderately low. Moderately high levels are observed in the less responsive groundwater bodies of the Paris Basin, which are still showing positive effects from excess recharge during the last two winters. Moderately responsive groundwater bodies around the Paris Basin and Artois are more sensitive to a lack of autumnal recharge, with levels ranging from close to normal to moderately low.
Forecasts
The forecast for responsive groundwater bodies remains uncertain, as they are highly dependent on rainfall infiltration in winter and spring. Depending on local cumulative rainfall, the situation could evolve in the space of just a few weeks.
Groundwater recharge is expected to continue in less responsive groundwater bodies along the Rhône-Saône corridor, and levels should improve gradually. The forecast for the end of winter is relatively good, even though when the recharge period will end remains uncertain.
The forecast is fairly optimistic about the lack of winter drought at the less responsive groundwater bodies of the Paris Basin, where groundwater levels are currently above monthly norms. However, given the exceedingly late onset of recharge in this area, the forecast for spring 2026 is uncertain.
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 December 2025, based on data acquired up to 15 December 2025.
Data source: ADES (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.