Drought: “A Risk of Cuts in Urban Areas”… Are we Going to Run Out of Drinking Water in September?

DRY: As water restrictions affect 62 million people, the issue of drinking water supply becomes more pressing

River flows falling sharply, two thirds of groundwater below normal, almost half of small rivers out of flow or dry… In mid-August, drought hit France in an unprecedented way and the picture is worrying. According to the Minister of Ecological Transits, Monique Barbut, as of the 12th August, “more than 40,000 people” were affected by water cuts at the tap, with 97 municipalities supplied with water via cisterns or bottles.

“Ecosystems are today in a situation of suffering”, notes Eric Sauquet, hydrologist at INRAE. We are clearly in a situation of extreme drought, with consequences on all uses linked to water and on ecosystems. “In total, in 96 departments, restrictions on drinking water have been put in place.

Alerts for 3 million people

Concerns relate in particular to the drinking water supply, under tension in 50 French departments. At the beginning of August, “the supply of more than 550,000 inhabitants was thus considered to be in tension, and the supply of nearly 3 million inhabitants placed on alert”, added the minister at the end of the Anticipation Committee and hydrological monitoring on the 12th August.

What will the situation be in September? This will partly depend on the weather and possible rain. With the fifth heat wave, the drought soils continue to worsen, notes Météo-France, reach record levels on a national scale, and are widespread throughout the territory. “In terms of hydrology, we are in a dynamic of reduction of the resource as we have experienced it since the beginning of the summer, because, there is an inertia effect, the soil and vegetation will benefit first and foremost from possible precipitation”, explains Eric Sauquet. The next few days promise to be without any notable precipitation. The situation is likely to be very tense for a large majority of rivers. “

If there is precipitation, it must last for a long time, a big storm would have little effectiveness in recharging the water tables. “We will need regular rains with intensities that are not too high to avoid saturating the infiltration capacities of the soil and allow water, little by little, to infiltrate into the water tables”, explains Éric Servat, hydrologist and associate professor at the University of Montpellier.

“More sensitive territories”

While France is in a situation of generalized low water, that is to say minimum flow of watercourses, the researchers interviewed explain that it is difficult to know which areas are more at risk of water cuts. “Certain sectors are more sensitive, we must look in detail at the vulnerability of territories”, underlines Eric Sauquet. The map Vigieau, updated by the ministry, details the areas affected by the different levels of restrictions, and makes it possible to find the departments under tension for the drinking water supply, specifies the Ministry of Ecological Transition.

In bright red, the Vigieau map shows water restrictions in crisis areas. - Screenshot/Vigieau

“It varies greatly from one territory to another”, adds Simon Porcher, professor of management sciences at Paris Dauphine and author of The end of water? (ed. Fayard). In Brittany, where we depend a lot on rivers and reservoirs, rains quickly increase the volumes available. In the East or the Paris Basin, where resources rely more on groundwater, improvement is often slower. The rains will do good, but they will not completely eliminate the risk of access to drinking water in certain areas. ”

In 2022, during the last drought, more than a hundred municipalities in France were deprived of drinking water, declared the then Minister of Ecological Transition, Christophe Béchu. These cuts mainly affect rural areas, mountain or isolated areas. “But this year, we have a risk of water cuts in towns with several thousand inhabitants, specifies Simon Porcher. Providing 10,000 people with water is more difficult in terms of logistics. “

80% of levies for the economy

In the Manche, the territory of the Saint-Lô agglomeration rose to drought crisis level on the 4th August. Residents, businesses and farmers are called upon to reduce water consumption “to limit the risk of outages and ensure the continuity of water distribution throughout the territory”, indicates the agglomeration in a press release.

“From mid-July, there were water restriction orders in France. They aim precisely to guarantee access to drinking water in September”, explains Simon Porcher. Individuals are advised not to use drinking water to water gardens or clean cars. But the bulk of the effort concerns the economy. “Over a year, 80% of water withdrawals are directed towards economic uses, he continues. The fact that we can have drinking water in September depends above all on the slowdown in economic activities such as agriculture, industry, tourism, etc. Needs must be prioritized. ” Which generates conflicts of use, everyone being able to consider their use a higher priority. A message of sobriety that Monique Barbut also carried.

For the researcher, France remains “in crisis management, emergency”, and is not adapted to face the risk of drought, increased due to climate change. We have not yet improved the performance of all our infrastructures, but also of our natural environments. We need to make the last straw more effective”, he says. “We need to have a real capacity for anticipation and investment and to put in place suitable solutions”, adds Éric Servat. And there are many ways to achieve this, such as reducing leaks on networks and pipes, reusing wastewater more, modernizing irrigation systems for agriculture, using each water withdrawal several times when possible, improve storage or restore wetlands.