Is France ready in the event of floods like in Spain? The examples of Cannes and Mandelieu-la-Napoule

Residents of Cannes (Alpes-Maritimes) see these speakers every day, hoping to never hear them. Because, if they sound the alert, it means that the water level is about to rise dangerously. There are 380 across the city. “It’s reassuring, just seeing them”testifies a local resident at the microphone of TF1, in the on-site report of the 8 p.m. news, visible in the video at the top of this article. This is one of the many measures put in place by the municipality to try to reduce the risk and impact of floods, since those of 2015, which left 20 dead in the department.

Another local measure: widening the beds of watercourses, such as that of La Frayère. “The width increased from 14 to 25 meters, over a length of more than 400 metersexplains Aurélien Béhague, deputy general director in charge of the water cycle of the Cannes Pays de Lérins urban community. This work makes it possible to limit overflows, since they allow a hundred-year flow rate to pass through.that is to say the maximum flow during the flood peak.

For his part, the mayor (LR) of Cannes, David Lisnard, wants to present to us… a vast hole, dug in the middle of the homes: “Here, there was a social housing building and there, private villas with gardens. We deconcreted everything to create this water retention basin.” If there were a disaster of the magnitude of that of recent days in Valencia, Spain, does he think his town would be ready? “We always try to bereplies the city councilor. The need is to say that there will be other floods, despite our very expensive developments (the municipality has invested 150 million euros over 18 years, editor’s note). And in this case, to adopt the right behavior. Hence the ardent demand to have good alerts, good forecasts.”

On September 23, when a vast shopping street in downtown Cannes found itself under water, the mayor criticized Météo-France for having only triggered yellow and not orange vigilance, essential for the alert is immediately disseminated to communities. Several climatologists, such as Christophe Cassou on the social network “unpreparedness and mal-adaptation in the face of climate risks” at the political level.

Which raises the question, in addition to the inconsistency of urbanization, of the effectiveness of warning systems. Deployed across the entire national territory since June 2022, the FR-Alert system (new window) should theoretically “warn in real time anyone with a mobile phone of their presence in a danger zone”via a short warning message, written by the prefecture and immediately sent to telephones within the geographical area concerned, accompanied by a shrill noise supposed to sound even if your cell phone is in silent mode.

But in practice… “Messages do not necessarily get through depending on the operators and the power of the networkrecognizes from TF1 Sébastien Leroy, mayor (LR) of Mandelieu-la-Napoule (Alpes-Maritimes), a municipality among the most exposed in the country to the risk of flooding. What we saw during the last alert, launched around ten days ago with the FR-Alert system, is that a good third of the population did not receive it.” An observation that itself sounds like an alarm signal…

Finally, on an individual scale, but always with the support of communities, which can provide it directly or participate in the purchase via public aid (see the QR code in the video above), there is waterproof equipment allowing protect, at least in part, your home or business from a flood. Let us cite, pell-mell, the cofferdam, a small PVC and rubber barrier costing 600 euros, its inflatable and tailor-made alternative at the same price, or the tarpaulin folded and wrapped around a float, which can surround an entire construction and automatically activating, like an airbag, as soon as the water level rises, at 500 euros per linear meter, therefore 20,000 euros on average to surround a house.