The phenomenon is rarely filmed.
The Issole, a Var river that has been dry for months, came back to life at the beginning of February after the heavy rains of recent weeks.
A fascinating scene, captured on February 10 by Pierre Antoine Florentin, amateur photographer.
After the heavy rains, the Varois goes to the banks of this watercourse of around forty kilometers.
Pierre Antoine Florentin intends to film the return of the river to its bed.
“
But when I arrived around noon in Besse-sur-Issoire I noticed that it was too late,”
says the photographer
.
The water has already returned.
» He doesn't know that it's his lucky day.
After taking a few images, Pierre Antoine Florentin decides to take more photos in Cabasse, 10 kilometers downstream.
On site, surprise: not a drop of water.
Wooden debris blocks a little higher.
But the water ends up arriving, to the great joy of Pierre Antoine Florentin who films the scene.
“
I hear the cracking of the wood, then the sound of the water flowing and I see the little brown wave coming down towards me,”
says the thirty-year-old
.
I thought of a lava flow, but lava destroys everything, it was more like the return of life!”
The images are beautiful, but there is nothing harmless about this event.
Quickly, the level rises, the waterfalls resurface as if by magic and the small brown wave gives way to the torrent.
“
It grows quickly, in a few minutes, we go from five or six centimeters deep to 80 centimeters,”
says Pierre Antoine Florentin
.
Entire tree trunks are swept away.
» Cautiously, the photographer continued down the river to continue filming.
“
It’s a very ephemeral phenomenon that I wanted to capture at all costs.
»
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Towards a new drought?
How can we explain that a watercourse can rise from its ashes so suddenly?
The Issole has its source on the Agnis plateau, in the hills of La Roquebrussane and Mazaugues, about twenty kilometers from Besse-sur-Issole.
“
It is a limestone area with large underground reservoirs, which are unfortunately relatively empty, due to precipitation deficits of around 30% in 2022 and 2023,”
explains Benjamin Van Lunsen, deputy director general of the joint union of the 'Argens which plays the role of a local water resources observatory.
This explains why many rivers, such as the Issole, had been dry for two years, whereas they are usually dry only in the summer.
“
Since the fall of 2023, there has been relatively little rain,”
continues Benjamin Van Lunsen.
Then on February 9, there was 90mm in one day, or tenth of the annual rainfall.”
With this sudden precipitation the water ran off more, giving rise to this sudden wave phenomenon.
As droughts are becoming more and more frequent, this phenomenon could occur more regularly in the Var and in France in general.
“
According to recent studies by Grec-Sud, a group of experts on the climate in the Provence Alpes Côte d'Azur region, the region's annual rainfall is expected to drop by 20 to 30% in the coming years
,” continues Benjamin Van Lunsen. .
The rains should be less frequent, but more intense, leading to significant runoff phenomena like that witnessed by Pierre Antoine Florentin in the bed of the Issole, or even floods.
Whatever happens, the little Var miracle could be short-lived.
“
The Issole still flows today, but it goes down day by day
,” says the photographer, with supporting images.
“
The flow has gone from 12,000 liters per second at the height of the flood, to around 30 liters per second in recent days,”
adds Benjamin Van Lunsen.
And this concerns many other rivers in the department, even if it is the Issole which was filmed.
The Nartuby, for example, near Draguignan, is already dry.
» In other words, if it does not rain in the coming days, Issole should soon suffer the same fate... Until the next episode of heavy rain.