Nuclear power plants, agriculture: who uses water in France

Even if the rain returns to France, France risks not escaping a new drought this summer. With her, the controversies are already returning to television sets, social networks and the benches of Parliament.

Because the conflicts of use of this crucial resource, destined to become increasingly rare with global warming, are already on everyone’s mind. Who are the biggest water consumers in France? Farming? Nuclear power plants? In reality, there is some confusion between withdrawals and net freshwater consumption.

Reduce electricity production

Power plants, mainly nuclear, represent half of the withdrawals from nature: nearly 17 billion cubic meters per year (excluding hydroelectric power plants, on average between 2008 and 2018, according to figures from the Ministry of Ecological Transition). Their turbines run on steam. They are also equipped with cooling circuits which also require a source of cold water.

They therefore take large quantities of water from nature, from rivers with sufficient flow or from the sea. Too great a drop in the flow of large rivers such as the Rhône and the Loire could therefore cause them to become stopping and amputating the production of electricity, as planned last summer .

Part of the water used is then rejected at the source. This is the case for all the water withdrawn if the cooling circuit operates in an open circuit (which is the case for 26 of the 56 three-color reactors).

But if it is a closed circuit, the cooling is done in air-cooling towers and the water is evacuated by evaporation, giving rise to the famous white plumes. Part of the water withdrawn (40%, according to EDF) is then effectively “consumed”. In total, the power plants thus absorbed on average 30% of net annual freshwater consumption between 2008 and 2018.

Focus on summer months

Agriculture, on the other hand, only returns to nature a small proportion of the water it uses. “It is estimated at 20%,” says Régis Taisne, water specialist at the National Federation of Concessioning and Regulated Communities (FNCCR). As a result, the share of irrigation, limited to only 9% of withdrawals, rises to 45% of net annual consumption over the same period (2.4 billion cubic meters per year). And this number tends to increase.

“This annual average also masks a strong concentration on the summer months”, also recalls the specialist. According to the Ministry of Ecological Transition , the months of June, July and August alone absorb 60% of total consumption in France. And in certain regions such as the Southwest, agriculture absorbs more than 90% of the country’s summer consumption.

As for the production of drinking water, it represents 17% of withdrawals and 21% of water consumption in France. Showers, laundry, gardens and swimming pools represent an average consumption of almost 150 liters of water per day and per inhabitant. But again, these figures vary according to the period and the territories.