The water reservoir "barrage de la Chèze" supplies half a million French people around the city of Rennes with drinking water.

But right now it is only half full, and the water level is dropping by several centimeters a day.  

- During October, we had 25 percent less rain than usual, and 3 degrees warmer than usual.

So much of the water evaporates, and the dam is not replenished, says the head of the local water authority EBR, Laurent Geneau.

Forbidden to wash the car

Right now, they are working hard to get people to save water.

The local water authority in Rennes distributes free nozzles that cut water consumption in household taps in half.

They have also introduced restrictions that prohibit watering the lawn and washing the car.

- We don't know if the water will be enough.

If we have a very dry winter, we could have big problems next summer, says Laurent Geneau.

The farmers were affected by the drought

In the same area, Marie-Edith Macé runs a farm with 50 dairy cows.

Like many others, she had a record low corn crop this year, and milk production dropped sharply as the cows' pasture dried up in the pastures.

- I had to feed the cows with last year's fodder stock that I had to give them now in November, says Marie-Edith Macé.

Adaptation to a warmer climate is required

The methods used today;

such as reusing waste water and desalinizing seawater - are not enough, says the head of the country's consolidated water authorities, FNCCR.

- Climate change will not only be countered with new technology - we need it - but behaviors also need to change, says Régis Taisne.

Above all, everyone must think about saving water, but agriculture must also adapt to cope with a warmer climate, he believes.

- Plants such as corn, which need a lot of water, are not adapted to our climate.

Now they talk instead about growing crops that come from Africa or the Middle East.

The difficulty there is that people don't eat them yet.

So there is a need for both climate-adapted crops, and for the food industry and consumers to change their eating habits.