France’s historic drought: most underground reservoirs at below-average levels
July 2026 saw water levels drop in 94% of aquifers
More than half of France’s underground aquifers are at below-average levels for the season, after a lack of summer rainfall has seen supplies dwindle.
Aquifers are underground layers of rock or sediment that hold groundwater, and are an important source of water for homes, agriculture and industry, in particular during periods of drought.
As of August 1, 63% of the aquifers were at below-average levels, stated the Bureau de recherches géologiques et minières (BRGM) in its monthly report.
This is compared to 44% at the same point last summer.
In addition, 94% of measuring points recorded aquifer levels dropping in July 2026, with only 2% recording increases in levels.
Areas where tables are at their lowest include northern and eastern France, as well as central areas west of Clermont-Ferrand.
Only the area south of Paris, and pockets of Occitanie and Nouvelle-Aquitaine are at above-average levels.
Even in areas where water is sourced primarily from rivers and not underground aquifers (marked grey on the map) water shortages are taking place with as many as half of France’s small rivers and streams now running dry.
Shortages mean that currently more than 40,000 people are without access to tap water.
Long-term impact of drought
The low levels are both a symptom of, and a contributing factor to, France's historic 2026 drought.
In order to preserve water resources, all of mainland French departments now have at least one area either facing water restrictions, or issuing warnings to be careful over tap water usage.
These restrictions may last into the autumn, potentially winter, in order to allow the worst-hit aquifers to replenish.
Minister for Ecological Transition Monique Barbut has previously stated this much, saying that they could go on well into autumn.
Following steady rain at the start of the year, France has seen historic low levels of rainfall this summer, including certain areas going without a single drop of rain across July.
Excess water has also been required for tackling wildfires this season, with France set to record its most damaging year for blazes following several major fires.
As successive heatwaves have hit the country, soils have dried out, meaning ensuing autumn rainfall will need to dampen soils to make them permeable even before further rainfall can begin to replenish aquifers.
Alternatively, farmers would need to use scant remaining resources from aquifers to dampen grounds before any rainfall, although this can never be guaranteed.
However, this is not uncommon for summer.
“This situation is typical for the season. Rainfall from often violent storms does not infiltrate the soil effectively. Furthermore, high temperatures during this period have promoted evapo-transpiration and increased plant water demand. Water withdrawals for irrigation and tourism may have locally accelerated the drop in levels,” BRGM said.
You can read the full report, as well as find an interactive map comparing levels between 2025 and 2026 on the BRGM website.
