During March 2021, the general trend in water table levels has reflected the gradual end of the winter recharge period. Reactive aquifers, which are sensitive to low rainfall, experienced a downward trend, while recharge continued in inertial aquifers.
Most aquifer recharge in 2020-2021 took place from the end of February onwards. Recharge was well above average due to substantial amounts of effective rainfall. The situation in March is satisfactory over much of the country, with moderately low to high levels. However, reactive aquifers are deteriorating rapidly due to the lack of significant rainfall in recent weeks. The situation is less favourable, with moderately low to low levels, in the alluvial and karstic aquifers of the Montpellier, Nîmes, Provence and Alpes du Sud regions and for the deep aquifers of the Rhône, Saône and Sundgau corridors.
In April, unless there is exceptional rainfall, the reverse trends in inertial water tables are expected to continue, marking the end of the recharge period. Inertial aquifers in the Paris Basin should remain at close to normal levels during the next few weeks. Inertial aquifer levels in the Rhône-Saône corridor should remain below normal. In reactive aquifers, the trends and situations will depend on rainfall and vegetation recovery.