Drought: desalinating seawater, an effective solution to overcome the lack of water?

Chloé Lagadou, edited by Ophélie Artaud 06:21, August 08, 2022

More than 100 municipalities no longer have access to drinking water.

In question, the drought which affects all of France and a rainfall at its lowest.

So to avoid getting stuck, some municipalities have recourse to the desalination of seawater. This is particularly the case on the island of Molène in Finistère or in the village of Rogliano in Corsica.

But there is also the island of Groix, in Brittany.

Consequences on the marine environment

To produce its drinking water, the island of Groix plunges a pump into the sea, which then pours the water into a large tank to remove the salt.

With the arrival of vacationers, the population doubled and the water reserves ran out.

"We knew we would have water until about mid-August and after that there was no more drinking water available on the island of Groix. Our water desalination unit of sea will bring us 500 cubic meters more per day, which will allow us to pass all the summers without problem", explains Fabrice Loher, president of Lorient Agglomeration.

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A last resort solution for the island of Groix.

But for Esther Delbourg, environmental economist, these factories are energy-intensive and can damage marine environments.

"It takes two liters of salt water to produce one liter of drinking water, so the liter of salt water that we collect and that we will have to throw into the sea is extremely salinized and can be hotter than the temperature of the sea. When it is released, it can heat the surrounding water or bring back such an amount of salt that all living species suffer the effects."

The specialist specifies that the best solution to mitigate the consequences of the drought remains to recycle wastewater.