Since July, Nantes Métropole has stopped the practice of "flush cleaning" using large washing machines.
Other water-powered gear and tools are also used less.
The approach should be amplified with the use of rainwater for cleaning.
It was initially an emergency measure, in response to the drought affecting a large part of France.
But as the rainfall deficit continues, it is gradually becoming a new working method, which illustrates “the city's necessary adaptation to climate change”.
Since July, the metropolis of Nantes has decided to do without most of its water-intensive machines to clean the roadway.
About fifteen “large washers” and “mini-washers”, which generally do not go unnoticed because of the noise they generate, are thus left in the garage.
Objective: drastically reduce the community's water consumption in order to “preserve the territory's drinking water resources”.
“We stopped what is called the cleaning with large waters, explains Eric Bouchet, head of the urban cleanliness service on the Nantes-Loire pole.
These were large vehicles that sprayed the roadway with hydraulic sweeping and a system of ramps.
We sent water, a lot of water, it allowed to completely clean the roadway and to push the waste to one side, before sucking it up.
Although much less wasteful of water, “vacuum cleaners” equipped with rotating brushes are also used less, as are high-pressure jets.
“The rendering is not the same”
How to leave the city clean in these conditions?
The absence of machines is compensated by increased use of dry equipment (electric blowers, leaf vacuums, etc.) and, above all, by more manual pick-ups with tools.
Except for the market places, where, "for reasons of hygiene", a washer still goes to the location of the fish and vegetable stalls.
The first report on water consumption is spectacular, according to the metropolis, which advances the figure of “90% water saving”.
“For the city center of Nantes and the island of Nantes, we can go up to a water consumption of 60 m3 per day.
Since July, we have gone down to 7 or 8 m3 per day.
It's very significant,” explains Eric Bouchet.
The change can be seen, however, a little, also, in the streets.
“The rendering is not the same.
It creates more dust, it gives less of a clean appearance than a rinsed sidewalk,” admits Eric Bouchet.
However, complaints would be marginal.
The association of Plein Center traders, for example, says it has "not been alerted to criticism" from its members.
“The level of requirement is very different from one individual to another, observes the head of the urban cleanliness department.
We are in the same situation as a few years ago when we decided to stop using phytosanitary products.
There was a lot of concern about the proliferation of weeds in public space.
In the end, most residents got used to it much more easily than we thought.
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Soon rainwater and pool water
On stubborn or smelly dirt, such as urine or dog excrement, “no choice but to clean with water using a booster pump”, specifies Laurent Tenaud, city center coordinator technician for Nantes Métropole .
A public cleanliness agent also argues that the development of manual cleaning "can be restrictive over time because there are a lot of repetitive gestures".
In the meantime, the Nantes metropolis wants to go further in the preservation of drinking water and is preparing the deployment of rainwater storage tanks for its technical centers.
"There are centers that are already working with water recovered from roofs, but these are limited volumes," says Laurent Tenaud.
A study is also underway for the recovery of water from swimming pools and its reuse to strip the streets.
More broadly, the reuse of water from Nantes paddling pools is also encouraged to water green spaces.
The installation of a “drip” system for watering “a thousand young trees” is also underway.
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Planet
Nantes
Pays de la Loire
Cleanliness
Drought
Water