The public fountains in Volvic, the home of one of the world's most famous mineral waters, have been turned off.

Just down the road from the bottling factory at the foot of the old volcanic hills of central France, streams once powerful enough to drive flour mills are drying up and villages are under a hosepipe ban.

Campaigners such as Sylvie de Larouziere, head of the water conservation group PREVA, point the finger at the Volvic plant. "It seems like it's always getting bigger," she complained.

A local aristocratic trout farmer is suing the company, owned by French multinational Danone, after a stream that fed his 17th-century fish ponds abruptly dried up.

The Puy de Dome region is sometimes called the "water tower" of France, with heavy and reliable rainfall meaning farmers downstream used to slosh around in their fields because the soil was so wet.

But those days are long gone. In early May with supplies "abnormally weak", authorities imposed a hosepipe ban and outlawed the filling of swimming pools in 31 nearby districts, hitting some 60,000 people.

Volvic's public fountains were switched off and villagers fear water cuts this summer.

"It was a shock," said Maria-Louisa Borges, a retired cleaner who has lived in Volvic for 50 years. "We're just coming out of winter."

The restrictions, affecting somewhere so famous for its abundant water, underline the worsening strains on supplies in France and the competing demands for an increasingly rare resource.

Two-thirds of the country's water tables are below normal, Environment Minister Christophe Bechu said last week as he voiced "very serious concerns".

But it also raises questions about the future of France's enormous mineral water industry, already decried by environmentalists for billions of plastic bottles it produces annually.

France is both the world's biggest exporter of bottled water and the home of its most famous brands from Volvic to Evian, Vittel to Perrier.

'Critical state'

For decades, experts have been warning about the risk to global fresh water supplies posed by climate change, population growth, and over-consumption.

Problems have been gathering in France, though mostly beyond the public eye. But this winter, the country went a record 32 days without rainfall, from January 21 to February 21. Even villages in the foothills of the snow-topped Pyrenees mountains are having to be supplied by truck.

The dry winter followed punishing heat last summer with months of drought and high temperatures parching even the normally lush Alps and rendering mighty rivers like the Rhine unpassable for barges.

President Emmanuel Macron said it spelled "the end of abundance".

"Climate change is adding to an already degraded situation, with long droughts, heatwaves but also winter droughts," former French environment minister and a Green MP, Delphine Batho, told AFP. "That's leading to a critical state for drinking water."

In a sign of conflicts experts anticipate in future, activists opposed to farmers building rainwater-capture facilities in Batho's constituency in western France clashed violently with security forces in March.