Carte de France de l’état des nappes d’eau au 1er mars 2018.
© BRGM
Water table levels on 1 March 2018 varied between regions.
About half (52%) of all groundwater tables were at moderately high to very high levels and only 26% of them were at moderately low to very low levels. The other measurement points (22%) had medium levels. This confirms the now significant effect of rainfall in the first half of the year. With the exception of a few areas, it can be noted that groundwater levels across a large part of the country benefited from a much-needed recharge due to the rainfall over the last two months.
Trends in water table levels
The general trend as regards the change in water table levels reflects significant winter recharging, for almost two-thirds of the points monitored (60%), a trend which is still moving upwards. However, the downward trend in the level of the groundwater table has intensified (now at 26% of the measurement points) in comparison with the beginning of the year (a 12% drop was noted on 1 January 2018). The number of measurement points whose level is stable has also decreased (14% compared with 25% on 1 January). This situation shows that the period of switching from high water levels to a drop in levels seems to have begun, which is a little premature. We are gradually moving towards the end of the winter recharge, unless the March rains are heavy.
The groundwater level situation on 1 March 2018 reflects an effective winter recharge but whose effects seem to be diminishing fairly early.