Le Figaro Nantes
Images of arms of the river almost dry, a very low water level: last summer, the course of the Loire was often used as an example to illustrate the drought.
Another resulting phenomenon, but much less visible, threatened the drinking water supply of the Nantes metropolitan area.
This is the rise of a silt plug in a so-called "sensitive" area because it is located near the Mauves-sur-Loire pumping station.
This is where the water from the river is collected, which is then sent to the La Roche factory in Nantes for treatment.
This infrastructure supplies approximately 85% of the inhabitants of the Nantes conurbation and 45% at the departmental level.
Problem: the presence of the sludge near the pumping station increases the particle content of the water, which makes it more difficult to purify and can therefore slow down production.
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"There was a real tension this summer"
, recognizes Robin Salecroix, the vice-president of the metropolis in charge of water and sanitation with
Figaro
.
“We never came close to disaster but it is true that this exceptional drought challenged us
,” he says.
As a result, the community is putting its hand in its pocket to adapt to the changes caused by global warming and to prevent the taps from running dry.
“We already had a reflection on the subject because we must be in anticipation but it is true that the accentuation of the difficulties accelerated our approach”
, underlines the elected official.
A dilapidated pumping station
In order to "secure" the drinking water supply of nearly 600,000 people, parallel and complementary studies will be launched.
The first concerns the Mauves-sur-Loire pumping station.
“It was built in 1989 and put into service the following year.
It shows signs of wear.
There is no specific concern, but we must plan ahead to maintain its sustainability
,” explains Robin Salecroix.
Voted on December 2 in the metropolitan office, this feasibility study is estimated at €250,000.
Its objective is also to allow adaptation of the equipment “
to the consequences of climate change”,
mentions a press release from Nantes Métropole.
The second study is more global and concerns both
“the meshing of the network”
and the
“diversification of the resource”
.
What should be understood?
“For diversification, the idea is in particular to think about the interest of setting up another pumping station in the Loire upstream of the one that already exists
, deciphers Robin Salecroix.
As for the mesh, the idea is to better connect the existing networks because at the moment we supply water but ours is not supplied by other factories.
»
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This vast study carried out on the initiative of Nantes Métropole, the Loire-Atlantique department, water-producing distributors and the Water Agency should be launched in 2023. Its budget is not yet known.
“It is still being negotiated”
, slips the elected official.
Avoid leaks
Beyond these two studies, Nantes Métropole has decided to invest heavily in the existing water network.
On September 6, Johanna Rolland, the president of the community, announced that nearly 200 million euros were going to be devoted to
"the good management and distribution of drinking water in the territory"
.
“The goal is to have as little loss as possible. Our rate of return is 90%
(it is 80% on average at the national level, editor's note)
but we must do better because the volume lost remains significant”
, indicates Robin Salecroix.
