Carte de France de la situation des nappes au 1er mai 2020.
© BRGM
The 2019-2020 recharge ended between mid-March and the end of April. It was well above average, due to early and significant amounts of effective rainfall. This resulted in particularly high levels in some water tables in March 2020.
In April 2020, the depletion started and the general trend was towards decreasing levels. However, the most passive aquifers in the Paris basin were still rising slightly, but their recharge ceased in April. Locally, on the Mediterranean coast, the excess rainfall at the end of April allowed the water levels to stabilise or even increase.
The lack of rainfall recorded from mid-March onwards accelerated the depletion of the aquifers. Nonetheless, the situation remains satisfactory, with levels around medium to high across a large part of the country. The water-table situation is less positive in the Alsace plain, the Saône and Rhône valleys and in the Massif Central.
The exceptionally high rainfall forecast for May could slow down or interrupt the depletion and improve the situations, particularly in the reactive water tables.