Below the large concrete wall of the Soulcem dam, in Ariège, the level of a calm body of water fell 27 meters lower than usual, on the same date.
1,500 m lower, 100 km further north, the impression is the same in the heart of Toulouse, with the low Garonne, from which emerge banks of stones, witnesses of a year that was anything but wet.
“We have never known such a long period when the Garonne is so low, it has never started so early, and we are breaking records every day,” said Jean-Michel Fabre, president of the Syndicate. joint study and development of the Garonne (Smeag).
A situation that led the organization to trigger low water support from the beginning of July, these releases of water from reservoirs located upstream, supposed to maintain an acceptable flow in the rivers.
– Early low flow –
“Usually, the first releases of water take place at the end of July, beginning of August. There, we started on July 9 with very large volumes”, laments the chosen one.
At the height of the drought, 40% of the water that crossed the Pink City could come from releases ordered by Smeag and carried out by managers of water reservoirs such as EDF.
The low water level is not without consequence in the mountains, as at the Soulcem dam, built in the early 1980s very close to the border with the Principality of Andorra.
“In July, the volume released from the Ariège lakes (those managed by EDF, editor’s note) is twice the maximum of what had been done in the past”, points out Philippe Reffay, water-environment director for the South-West branch. of EDF Hydro.
“Each year, EDF Hydro reserves 53 million cubic meters in the Ariège dams for the low water level support of the Garonne. 70% have already been released over the past month and a half”, he underlines to AFP .
Guaranteeing the quality of water for the ecosystem of the Garonne basin, compensating for agricultural withdrawals, ensuring industrial activities and maintaining the level of drinking water for the million people who drink from the river: the role of these low water levels is multiple.
– The expected rain –
“Another problem is added, with the Russian-Ukrainian context, concerning the fact of having enough water to be able to produce electricity this winter”, explains Cécile Llovel, hydrologist in Toulouse.
“It’s the double penalty, it complicates management” for electrical operators, she says.
With many nuclear reactors shut down for maintenance and soaring gas prices due to the war in Ukraine, all eyes are on hydroelectricity, France’s leading renewable energy, which accounted for 11 % of the country’s electricity production in 2019.
“We had a good winter in terms of snow cover, but a very dry spring and summer, we hope it will rain”, supports Philippe Reffay, contemplating the historically low level of the Soulcem pond, overhung by the peak of Montcalm (3,077 m), highest point of Ariège.
“The place of hydro-electricity in consumption depends on rainfall”, specifies Mr. Reffay, while the level of EDF’s Ariège reserves is 20% below the average for previous years.
“From January to June we only had 150 mm of precipitation where we expected 300, plus very rapid snowmelt”, points out Cécile Llovel.
For the hydrologist, these meteorological conditions are “what we are tending towards more and more regularly with global warming, which has an even greater impact on the hydroelectric sector”.
For Jean-Michel Fabre, we will have to get used to and adapt to these ever longer and more intense droughts: “The year we are living through is what we were predicted for 2030, 2040, even 2050! We must accelerate on all the means implemented to store water and especially to develop our system”.