“It is each person who must be careful with water, not to waste water unnecessarily”, reminded Tuesday, May 10 on franceinfo Violaine Bault, hydrogeologist at the Bureau of Geological and Mining Research (BRGM), while 15 departments are still in a situation of vigilance or drought alert in France creating concerns about groundwater reserves. The situation “is very contrasting” depending on the region, notes Violaine Bault, with more or less recharged layers and levels “worrying” especially in Provence-Alpes-Côte d’Azur. And even if heavy rains were to arrive soon, it would be “already too late” to have an effect “on the groundwater levels”adds the hydrogeologist.
>> Drought: follow the live
franceinfo: Are there regional differences in the state of water reserves?
Violaine Bault: Yes there are regional differences. First of all, the recharge was very low this winter, during the period when the groundwater usually recharges. So we have a large part of the layers that are now below par. The situation is very contrasting. It is more satisfactory in the South-West, especially in Occitania where it has rained for the past two months and therefore the water tables have recharged. And in the North, we have aquifers which are much more inertial and which have a capacity to react less to the absence of rain. Elsewhere, the levels are much more worrying, especially in Provence-Alpes-Côte d’Azur to the south of Drôme, in Vendée, Charente and as far as Touraine where it rained very little this winter.
Should we be concerned about the state of these reserves? What could be the consequences?
The consequences can already be seen with prefectural orders restricting the use of water. And you should know that most of the large aquifers in France regulate the flow of rivers. So during the summer, when it’s not raining, if there’s always water in the streams, it’s because it comes from groundwater. So, if groundwater levels are low, they have trouble feeding the waterways. And therefore the levels of the rivers also decrease with an impact on the fauna and flora.
Would heavy rains in May help or is it already too late?
It is always beneficial since it allows the soil to be moistened and the vegetation to be nourished. And so this allows farmers not to irrigate, not to pump into the groundwater. Then, on the groundwater levels, it is already too late, since there is very little water that falls during the spring and summer and which manages to infiltrate to the groundwater.
What solutions do you recommend to save water? Will we need to save more in the future?
The BRGM is mobilized. We support the State services and the Ministry of Ecological Transition on all decision-making and forecasts for the summer. We will have to review our water consumption. This is what has already been done for several decades, in particular with the programs of the Water Agencies. But actually, it is each person who must be careful with water, not to waste water unnecessarily.