"Reducing losses in the distribution of drinking water supply systems is a considerable challenge in a context of tension", assures the metropolis of Nice, which will recruit a seventh leak tracker to limit waste on its network.
“We intervene to identify them and to have them repaired.
Our work takes on even more meaning with the drought.
We have been on deck all summer, ”explains one of them to 20 Minutes.
It was the alert of a “logger” that led Thierry Verjus to the corner of avenue Durante and rue d'Italie that morning.
One of these 366 sensors, distributed throughout the drinking water distribution network of the city of Nice, "detected an abnormal noise", explains this specialist, head of the team of "leak trackers" of the metropolis.
“We intervene to identify them and to have them repaired.
Our work takes on even more meaning with the drought.
We've been on deck all summer,” he says as he sets up his equipment.
The investigation with a Hydrosol, a kind of giant stethoscope, which he puts in the eyehole where the signal was recorded.
“We must first confirm the problem and then locate it precisely.
The diagnosis of Dr. Verjus falls.
It would be a leak.
Caused by what?
"Hard to say without opening," he continues.
Some pipes are made of ductile iron and are cracking.
Other times, it's the fittings that fail.
»
A treasure hunt to find water leaks
Plan of the network in hand, he then determines the directions of the pipes in the sector and begins his survey work.
You heat up, you cool down… A real treasure hunt begins.
Armed with another device, electroacoustic this time, that is to say whose sound is amplified, Thierry Verjus goes to inspect the roads.
Groping.
It starts on avenue Durante, towards the station.
He places the base of his sensor on the asphalt, settles down for a few seconds, concentrated under his headphones, then leaves.
He repeats the operation two or three steps further and so on.
"The sound goes away, it's not good".
The same on rue d'Italie, towards avenue Jean-Médecin.
White cabbage.
It is finally on the other side of avenue Durante that his "golden ear" (the nickname given to sailors responsible for listening to the sounds of the sea and recognizing potential enemies) and his 35 years of work will find the trail of the escape.
In front of number 11 precisely.
20 Minutes
can attest to this, in the device, the noise is indeed very present.
"We hear like the Pschiiiit of a tap", describes the specialist.
Spot to fix
The last step, with a "correlator", serves to locate the leak even more precisely.
Two sensors are installed several tens of meters away from the identified point and the device "calculates the speed of propagation of the sound wave", indicates Thierry Verjus.
He enters a few parameters into his machine, the nature of the pipe (ductile iron) and its diameter, and the verdict is in: the epicenter of the leak is located 35.1 m from the first detector and 11.7 m from the second.
“She is probably on the property line, he concludes after further tapping.
You must make an appointment with the syndic of the co-ownership in order to schedule, for security, a search for the private part.
Then, depending on the result, we will proceed with the repair.
“In the next few days.
And with construction machinery.
Four million euros of investment
In 2021 alone, 553 leaks were thus treated on the perimeter of the city of Nice, including 409 on connections and 144 directly on pipes.
For how many thousands (or more) of cubic meters of water lost?
Difficult to quantify answers the metropolis which took over the water service under management since 2015. But the community wants in any case to give itself the means to fight against this waste.
In seven years, the number of its "leak trackers" has increased from four to six and a seventh is being recruited.
"Reducing losses in the distribution of drinking water supply systems is a considerable challenge in a context of tension", she assures while the prefecture has placed Nice, among other municipalities, on "reinforced drought alert at least until September 18.
It also specifies having invested 4 million euros, just last year, for the renewal of the networks.
Planet
Drought: "There will never be a shortage of drinking water throughout the Nice metropolis", reassures Christian Estrosi
Planet
Drought in the Alpes-Maritimes: Azureans fined for non-compliance with restrictions
Planet
Nice
Drought
Water
Paca
Leak
Company