Groundwater tables on 1 September 2020
Map of water table levels in France on 1 September 2020.
Groundwater depletion continued through August and water table levels have fallen everywhere. This fall accelerated during the summer in sectors that had experienced a rainfall deficit combined with strong demand. The August rainfall events only affected certain reactive aquifers close to the Channel coast. This is normal at this time of the year: any summer rains that manage to filter down through the soil are absorbed by vegetation and rarely reach the water table.
The water table situation deteriorated in the east, with very low levels for the aquifer of the Alsace alluvial plain, but improved when moving south-westwards, reaching moderately high to high levels for the aquifers of the Atlantic coast and the Languedoc-Roussillon coastline. The benefit from last winter's abundant rainfall continues to be felt, and the situation in August therefore remains satisfactory for a large part of western France. The situation continued to deteriorate in the reactive aquifers of the Paris Basin, Lorraine and the Massif Central, which are all vulnerable to the lack of rainfall. Lastly, the situation was less favourable in those sectors that have been insufficiently recharged for several winters now: the aquifers of the Alsace plain, the Saône and Rhône corridors, and the eastern part of the Massif Central.
In September, levels of inertial aquifers are expected to continue their downward trend. For reactive aquifers, trends and developments will mainly depend on recharge due to local rainfall and demand for water.