The high cost and exclusive nature of Italy's best beaches cause regular disputes, but accelerating coastal erosion means some of them are now disappearing altogether.

Italian actors, intellectuals and the titled rich setting off for the beach this summer have been shocked to find that one of their favourite spots has all but vanished, thanks to encroaching development and violent winter storms linked to climate change. Traditionally, the cultural and political elites have soaked up the summer sun at Capocotta beach near Rome, which has a reputation for bohemian flamboyance and boasts Italy's only official nudist shoreline. But the golden dunes and beach huts have been swept away, leaving the literati fighting over a few inches of sand and how to rebuild.

"I realised something was happening three years ago when a beach kiosk from further down the sands floated past us in a storm," said Paolo Moscia, a lifeguard at the nudist section at Capocotta, which has drawn a mixture of gay bathers, ministers, musicians and hip film directors since Allen Ginsberg hung out there in the 1950s, and wild high-society drug parties gave birth to la dolce vita.

This year regulars arrived to find that their section was reduced to a trickle of sand and storms had engulfed 30 metres of beach, leaving the wooden restaurant renowned for its oysters and grilled squid close to toppling off the dunes into the waves. Moscia pointed at swimmers beyond the breakers. "This time last year people were strolling on the sand out there," he says. "If nothing is done, we won't be here in two years."

Experts blame development along Italy's rivers and the building of hydro-electric dams, which have slowed down the erosion of river banks and the flow out to sea of the tonnes of sediment and sand needed to replenish beaches after storms. "The Tiber sent 400,000 cubic metres of sand a year into the Mediterranean 25 years ago. Now it's down to 80,000 cubic metres," said Angelo Bonelli, head of the Italian Green party.

Francesco Lalli, a senior researcher at Italy's environmental research centre, Ispra, said Italy's beaches lost five million cubic metres of sand between 1950 and 2000. The losses caused by overbuilding are levelling out, he said, adding that there is now a suspicion that the storms chewing away at the beaches are more violent because of climate change. "Plus, we are seeing the initial effects of rising sea levels," he warned.

North of Rome, L'Ultima Spiaggia beach has fared no better than Capocotta. A long-time favourite of Italy's leftwing cultural elite, including the former prime minister Romano Prodi, the beach is tucked into the lower reaches of Tuscany. It is a retreat for philosophers, aristocrats and anti-Berlusconi politicians who convene every summer to eat wild boar and attend cultural conferences in nearby Capalbio, a medieval hilltown nicknamed "Little Athens". After storms left just a shallow layer of sand this spring, 15 metres have now been restored, thanks only to four truckloads of sand dumped by the local authority. But, according to the environmental centre Ispra, more than 1,000km of coastline is now eroding steadily.

Since the economic boom of the 1950s, working-class bathers from nearby Rome have flocked to the beach clubs of Ostia, near Rome. But they, too, are now watching their beaches slip away, prompting the regional authority to pump in sand scooped up from the seabed, part of a ¤26m scheme to bring 350,000 cubic metres of sand ashore to fill the gaps on almost 400km of coastline.

For patrons of the Sporting Beach Club in Ostia, where forlorn lines of changing rooms that once stood 150 metres back from the sea are now buffeted by waves, the new sand cannot arrive soon enough. "My parents came here before me and I am sticking it out," said Ivana Paolini, 55, "but it's tough when you have to swim out to sea past concrete pillars holding up the changing rooms."

An expert at the environmental group Legambiente said beach clubs were partly to blame for losing the sand on which they charge sunbathers for the privilege of stretching out. "The dunes which advanced to replace lost sand are being concreted over by the clubs," said Giorgio Zampetti. "By building beach clubs to profit from the sand, people are ensuring that sand will vanish."