Historic Cleanup Ends Century-Long Swimming Ban in River Seine

Following a century-long ban due to pollution, Parisians and tourists can now swim in designated areas of the River Seine. A major cleanup operation was completed to remove industrial waste, sewage overflow, and dangerous bacteria that had been contaminating its waters since 1923.

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The iconic River Seine opened its banks to swimmers on July 5, marking the end of a swimming ban that had been in place since 1923 due to severe contamination in its waters.

For decades, the river has been polluted by E.coli, enterococci bacteria and other contaminants, with industrial waste, sewage overflow, and urban runoff making it unsafe for swimming. 

Paris’s outdated combined sewer system, dating back to city planner Baron Georges-Eugène Haussmann’s 19th-century city planning, allowed untreated wastewater to flow directly into the river during heavy rainfall.

By the 1970s, about 60% of the city’s sewage was being dumped untreated into the river, and fish species had decreased to just three.

The historic reopening followed a €1.4 billion (US$1.6 billion) cleanup operation to make the river swimmable in time for the 2024 Paris Olympics, with open-water swimmers and triathletes competing in its specially treated waters.

Bastien Xu, a Parisian businessman who was among the first to take a dip when the ban was lifted, described it as a symbolic moment for the city: “The Seine River has always been seen as romantic, but now people can actually swim in it instead of just looking at it.”

“I was really excited. I felt lucky that we can swim there now after it wasn’t allowed for 100 years. My older French neighbors were envious because they never got the chance when they were young,” Xu told Earth.Org.

Three designated swimming sites are open along the riverbank – one near the Eiffel Tower, another close to Notre Dame Cathedral, and a third in eastern Paris – until the end of the month, welcoming some 1,000 swimmers daily for free. 

Tiné Leandro, a Belgian tourist visiting Paris, was also eager to take a plunge. “It’s not every day you get to say you swam in the Seine – a river that winds past some of the world’s most iconic landmarks,” he told Earth.Org.

Leandro noted that while many cities now embrace urban swimming, such as Berlin’s Spree and Boston’s Charles River, the Seine has a unique appeal. “Other cities may be ahead in terms of infrastructure, but the Seine has the charm and central location that elevate the experience,” he said.

Decades in the Making

The journey to make the Seine swimmable again has been decades in the making, with Paris officials and urban planners stepping up to undo the damage.

Then-mayor of Paris and later president of France, Jacques Chirac, first advocated for reopening the river for swimming in 1988, but his promises failed to materialize. 

Over the past two decades, levels of harmful bacteria contaminating the water dropped significantly following a series of interventions. The Olympic deadline provided the necessary impetus – and funding – to accelerate these improvements.

A cornerstone of the cleanup effort was the construction of a massive underground storage tank designed to prevent untreated sewage from entering the river during heavy rainfall. Wastewater treatment facilities throughout the region were also upgraded to modern standards.

NBC reported that by 2023, water safety tests showed the Seine was swimmable on around seven days out of every 10. The river’s biodiversity has also improved, with fish species increasing from three to 32.

“Historically in the rural areas, sometimes people’s household waste, like from their sinks and their toilets, would be discharged directly into small creeks or streams, which would then flow into the Seine,” Matthew Heberger told Earth.Org. 

The hydrologist, who works at the San Francisco Estuary Institute and specializes in water science and management, said new regulations prohibit cruise ships from doing so: “They created the infrastructure where they can connect to the sewage system to pump that out and have it treated properly. So they’re no longer allowed to dump it directly into the river,” he said. 

He added that advanced technology now allows for rapid bacteria testing, enabling quicker decisions about opening or closing swimming areas. 

However, Heberger warned that swimmers should avoid swallowing water and invited people with weak immune systems to exercise caution.

Last month, Pierre Rabadan, Deputy Mayor for Sport and the 2024 Olympic/Paralympic Games, said that over 40,000 people had used the swimming sites since their July 5 opening, despite nearly two weeks of closures due to rain-related pollution. 

However, public opinion has been mixed. Social media comments reflect lingering concerns about water quality, with some users referencing reports that some Olympians fell ill after competing in the Seine during the 2024 Games.

“So they didn’t see the Olympians get sick??!” one skeptical commenter wrote on Instagram, while another claimed the water contained “dead bodies… world war artifacts… trash everywhere.” 

These concerns are not entirely unfounded. In the lead-up to the Paris Olympics, the Seine failed multiple water quality tests, raising doubts about its readiness for competition. The situation prompted Paris Mayor Anne Hidalgo and other members of the Olympic committee to jump in the Seine last July to prove its safety.

A Climate-Resilient Paris

The Seine reopening represents a key legacy of the Paris Games and one of Hidalgo’s last major environmental projects in the city before she leaves office next year.

Under Hidalgo’s administration, Paris has converted the Seine riverbanks from busy highways to pedestrian-friendly areas and planted some 130,000 trees to create new green spaces across the city, Politico reported. 

She also implemented several anti-car policies, including hiking parking fees for SUVs, closing roads in front of schools, and expanding sidewalks at the expense of street width in a bid to improve air quality in the French capital.

According to an April report by Airparif, a non-profit that monitors Paris’s air quality, harmful air pollutants have decreased by 50-55% since 2005.The city’s official figures released in August show that reduced speed limits have also made Paris quieter and decreased the number of road accidents. 

Continued Efforts

Heberger stressed that maintaining the Seine’s improved water quality will require ongoing commitment, a sentiment echoed by other environmentalists.

“The battle is ongoing. The movement to clean up the river is going to create more public pressure to continue those cleanup efforts and to make sure that they’re funded and to pass laws restricting pollution,” he said.

For now, as Parisians and visitors alike cool off in waters that have been off-limits for generations, the Seine’s transformation represents a rare environmental success story.

The timing of the Seine reopening also coincides with a severe heatwave gripping much of Europe. Record-breaking temperatures have been recorded in southwest France, with the national weather service reporting temperatures 12C above historical norms for this time of year.

Looking ahead, Mayor Hidalgo has framed the Seine cleanup as part of a broader strategy to adapt the French capital to climate change while enhancing quality of life for residents.

“Heatwaves are only going to increase,” she told AFP, adding that creating safe swim spaces will foster a “happier, and undoubtedly more peaceful life with our fellow citizens.”

Featured image: Bastien Xu.