The record temperatures that have been falling for several days in France are a powerful reminder of this: water is an essential commodity, but its availability has become particularly critical in recent years. In France, underground resources are suffering: the Bureau of Geological and Mining Research judged the situation in June to be “problematic in several regions”. The organization pointed out the repercussions on the flows of springs and rivers, but also on human and agricultural activities. More broadly, the European Commission recently estimated that almost half of the territory of the EU is currently facing a risk of drought.
Having become a major issue in recent years in France, water management is often synonymous with opposition. Emma Haziza is a hydrologist, doctor of the Paris School of Mines and created Mayane, an expert firm on the issue of risks and climate. She explains to L’Express why a “water war” is now possible in France.
Since when do we observe this drought in France?
Emma Haziza From the 2000s, we began to see more and more marked droughts, and in 2005, the first villages that could have a break in the drinking water supply. But there is really a shift from 2017, with the appearance of a particularly hot month of June, which could also be similar to what we experienced this year. At that time, the drought lasted for ten months, bringing us to a state of historic drought.
Yet, what is surprising is that the approach does not change from year to year. In 2018, as we experienced excellent groundwater recharge in winter, because we still had a temperate climate, the awareness of what had been experienced the year before was minimal, it was taken into account. counts as natural climatic variability. And 2018, 2019 and 2020 were also years of historic droughts, but each time it affected a different territory. If a water system was particularly affected in 2019, but was not affected in 2020, we tend to think that the phenomenon is over. However, if we take a step back and observe these phenomena on the scale of Europe, since Belgium is also beginning to experience historic droughts, we see a new trend. And for all that, there is not yet a real awareness or change in territorial practices.
What do you mean ?
Some territories rely on the fact that they have excellent water tables that could last thirty years. This is indeed the case in certain places, such as in the Paris basin or under the city of Nice. But pumping in the layers is not insignificant, because they will not be renewed as quickly as one could imagine before. In many other territories, there has been no winter recharge of the aquifers, and this makes them much more fragile. All this is not really visible yet because agricultural production follows: we are starting to have the first figures for wheat production, which remains good… In view of the rainfall for the year, this clearly shows that the groundwater was pumped extensively for irrigation. This leads us to believe that the system works, but until when?
The replenishment of these reserves is highly variable. In fact, from one slick to another, it can change very quickly, sometimes within a kilometer. Some tablecloths will have excellent refills and will be able to last several years, while others are already almost dry. In the Alpes-Maritimes, the water table is in excellent health, for example, and can largely supply the city of Nice despite the absence of rain, but conversely, right next to it, the Pays de Fayence risks running dry in the next few months, and the villages will no doubt be largely supplied by cisterns. This is already the case for some and it should continue.
Is this overexploitation recent?
No, it’s not recent, the aquifers had already been overexploited for a number of years. But we had quite good winter refills, even excess, which made it possible to respond to this exploitation of the resource. As a result, we did not realize this overexploitation.
What are the consequences ?
This excessive use of aquifers has consequences on water quality. Now, there is pollution in all our groundwater. In Loire-Atlantique, only 1% of deep water bodies are in good ecological condition, ie with acceptable physico-chemical standards, without massive chemical pollution. 40% of deep water bodies in France are in good condition. This means that we have largely forgotten about the preservation of our source.
This tension on resources also has the effect that we are starting to have water wars. This is what happens with the opposition to mega-basins, but also to the lake of Serre-Ponçon, in the Hautes-Alpes, where there is a tourist activity which is confronted with a local agricultural activity. All this generates very, very strong tensions.
In addition to irrigation issues, France also lacks drinking water. Some villages have already had to be supplied via tanks… Is this a new problem?
We saw these problems appear in the early 2000s, when we saw the result of this over-pumping: we were able to generate droughts ourselves, without climate change, due to land use. Since then, this reality has worsened under the effect of climate change, and we can clearly see this with the thermal anomalies observed in Northern Europe. France is at the heart of this very rapid change in temperatures, and therefore it is absolutely not suitable. In arid and semi-arid countries, we have been dealing with these problems for a long time, but in our country, when we still had a huge surplus on the resource, we closed our eyes to this problem.
There is something quite surprising, in fact, in thinking that we could run out of drinking water in France. How did we get here ?
We quickly forgot that France has experienced very strong tensions around water in its history. When you look at the French Revolution, there were tensions, which were linked to the fact that the king diverted half of the flow of the Seine for his own gardens, there were water carriers in Paris who supplied the richest … Then, with the development of Paris, then of the big cities, we bet everything on the purification of drinking water and we forgot the possibility of lack of water.
Today, that changes. In 2019, following the heat wave in June, the territory plunged more quickly into a state of drought, and it was noted that around twenty departments had had problems with the supply of drinking water. This is no longer an anecdotal problem. From now on, we can clearly see that this is accelerating. Last year, I had been to a village in Aude which had been forced to restrict water use to two hours a day. In everyday life, this means that the hairdresser in the village has to fill containers to continue working, and that the children who come home from school have to rush to take their showers. It’s another model, which we don’t really know but which is starting to arrive in France. We see that this kind of situation, which seemed unlikely, can happen to us.
How can we adapt? Can we make sure that doesn’t happen?
It’s very simple, you have to reduce the pressure on water resources and for that you have to save water. There are plenty of solutions, for example by installing aerators everywhere at the taps (a system that reduces the flow), and it would not be very complicated to halve the use of water in France. But the problem is that this perspective does not interest anyone. Why ? Because whatever the system, private or public, it relies on charges based on water consumption. If you halve the water consumption, you halve the bill, which means less money to maintain the networks, to operate the systems.
This is really the heart of the problem, this anomaly between a system which is supposed to provide us with drinking water supply but which is built to depend on our consumption. I was able to discuss it with the mayors of municipalities affected by the drought, they told me that they could not really reduce water consumption, because that would lead to a drop in funding for the municipality and the restoration of the network.
There is something wrong. On the one hand, you have messages encouraging people to save water, such as “take a shower, not a bath” which we see everywhere and which has been well integrated by the populations and, on the other, there is the reality in which we will do everything not to reduce the flow by two. In fact, rather than telling you “don’t take a bath, take a shower”, we should put aerators everywhere, add systems to reduce the consumption of toilet flushes… There are plenty of solutions, but there is no interest because water pays for water. In other words, it is the water billed to users that pays for the management of the supply circuits.
In the midst of all this, we completely forget the living environment, that is to say the river. Its wild side, its interest in terms of biodiversity has been completely overlooked. Each time we pump into a water table, we impact the river system and the rivers that are connected to this water table, and which risk running dry twice as quickly. It’s a living thing that is a small treasure of biodiversity that will be in total agony. The confrontation between all the users quickly makes us forget that the primary user of water is above all the living.