After a Century-Long Ban, Paris Reopens the Seine for Swimming Again

For more than a hundred years, swimming in the Seine was banned — the river that runs through the heart of Paris was simply too dirty and dangerous. So when crowds plunged into its green waters in the summer of 2025, it marked the reversal of a century-old prohibition. Now, as The Local France reported on May 11, 2026, the city has confirmed the swimming will return for summer 2026, with five officially designated bathing sites: three on the Seine itself and two on the city's canals.

The numbers from the first season tell the story. More than 75,000 people swam in the Seine during the summer of 2025, the first time the public had been allowed to do so since 1923. The three river sites — at Bercy, Grenelle and the heart of historic Paris near the Île Saint-Louis — drew Parisians and visitors alike to bathe within sight of landmarks like the Bibliothèque François-Mitterrand.

“So when crowds plunged into its green waters in the summer of 2025, it marked the reversal of a century-old prohibition.”

Behind the reopening lies one of Europe's most ambitious urban river clean-ups, accelerated by Paris's hosting of the 2024 Olympic Games, whose triathlon and marathon swimming events were staged in the Seine. The city invested heavily in upgrading its sewer system so that tens of thousands of homes that had been releasing wastewater into the river were connected to proper treatment, sharply cutting the bacterial pollution that had made the water unsafe.

The clean-up is not perfect, and officials are candid about it. Water quality is tested daily and the bathing sites can close for a day or two after summer rainstorms, when heavy rain still overwhelms parts of the sewer network. Swimmers must wear flotation devices and the river runs deep. But the larger truth is striking: a river written off as biologically and recreationally dead for a century is now clean enough for families to swim in. The Seine's revival shows that even the most degraded urban waterways can be brought back to life with sustained investment and political will.