The aquifers received most of their recharge for the 2019-2020 period from mid-March onwards. The recharge was well above average, due to early and significant amounts of effective rainfall. The situation in March was very positive, with levels around medium to very high across a large part of the country. The water-table situation was less positive in the far south of the Alsace plain, in the Saône and Rhône valleys and in the Massif Central. The water tables are still suffering from a lack of rainfall over the last few years, even though the beneficial effect of the recharge is becoming noticeable.
The trends observed in the water tables in March 2020 are uneven, due to a strong recharge at the beginning of the month followed by a lack of rainfall from 10 March onwards. The most reactive aquifers – on the Mediterranean coast, in the Jurassic limestone areas of the Paris basin and the Brittany bedrock areas – are very sensitive to rainfall. Their levels are stable or falling, which probably indicates the start of the summer depletion period. As regards all the other water tables in France, the heavy rains at the beginning of March allowed the recharge to continue. Unless there are further exceptional periods of rainfall, the reversal in trends is expected to continue in April, marking the end of the recharge period.