Swimming in the Seine has been banned since 1923, when public officials closed the waters off to would-be swimmers due to high pollution levels.

In the years since, the Seine, while known for its beauty as it traverses the city of Paris, is also reputed for being trash-ridden and dirty. 

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Despite this, organisers for the 2024 Paris Olympics and Paralympics hope to host several swimming events, including the triathlon and 10k swimming marathon, in the city-centre portion of the river.

The Seine will also play a crucial role for the opening ceremony of the Olympic Games, which will be held along a 6km course on the river through the heart of Paris.

People have attempted to push for a Seine clean-up in the past – former French President Jacques Chirac said in 1990 that he hoped to clean up the water enough so that he would be able to swim in it within three years.

This didn’t happen. 

However, the president of SIAAP (the Interdepartmental Syndicate for the Sanitation of the Parisian Agglomeration), François-Marie Didier, told BFMTV that in the 1990s, there were only three species of fish in the Seine and Marne rivers, while now, “there are 34 species of fish in the Seine and 37 in the Marne”, signalling progress that has been made in the last three decades to make the water less polluted.

The clean-up project

Despite the fact that the Seine’s quality has improved over the years, many Parisians still associate the waterway with bad smells, litter and dumped electronic scooters. 

According to a Slate report in 2021, nearly 360 tonnes of waste are collected from the water each year, which understandably does not make it very appealing for swimming.

The other issue is pollution from sewage. According to Vivienne Walt, who has covered the clean-up plan for Time magazine, “last year, 1.9 million cubic metres of untreated wastewater was spewed into the Seine”.

Walt spoke to city hall officials, who told her that dumping the wastewater was necessary “to avoid saturating Paris’ sewage network and flooding the city when especially heavy rain hits”. 

In order to solve this issue, a “water quality and swimming programme” was first launched in 2016, funded by €1.4 billion from the City of Paris and other local authorities.

To address the issue of heavy rains pushing untreated waste water into the river, a large rainwater storage tank near the Austerlitz train station was constructed. 

Public swimming

In 2021, Paris mayor Anne Hidlago’s son Arthur Germain, an endurance swimmer, swam the entire length of the Seine, from its source near Dijon out to the sea at Le Havre, as part of an environmental project.

After the Olympics –  if the waters pass safety standards for swimming – the next stage is public swimming which is scheduled from 2025.

The plan is to create 23 bathing sites along the Seine, with 5 in Paris itself and the rest in the suburbs and greater Paris area.

Two of the Paris sites will be located along the left bank of the Seine (in the 5th and 6th arrondissements), one at the edge of the Île Saint-Louis (4th), one at the port of Bercy (12th), and one in the Bois de Boulogne (16th).

These will be enclosed pool-type structures put into the river to create swimming spaces – similar to the temporary pool that is erected each year on the Canal Ourcq at Bassin de le Villette each summer.

At this stage it is not clear whether the Seine pools will be permanent or only for the summer, or what the rules will be on swimming in the river outside of the designated pool spaces. 

Baptême du tunnelier du bassin d’Austerlitz par @Anne_Hidalgo et @Prefet75_IDF
En stockant et traitant l’équivalent de 20 piscines olympiques d’eaux de pluie, il limitera les rejets en Seine

Une dépollution naturelle de la Seine : en 2024, nous nous y baignerons ! 🏊‍♂️🏊‍♀️ #JOP2024 pic.twitter.com/839LlfiNjk

— Colombe Brossel (@cbrossel) July 4, 2022

But will it happen?

According to Paris regional authorities, the stated goal within the “water quality and swimming programme” is to decrease three quarters of the pollution in the river by summer 2024. 

“If we reach this objective of reducing pollution by 75 percent, then it should be possible to swim in the Seine”, the préfecture of Île-de-France told BFMTV.

During the summer of 2022, daily samples of river water were collected, and “they were found to be either ‘satisfactory’ or ‘excellent’ 7 days out of 10. And that’s before all the work underway”, Pierre Rabadan, deputy mayor of Paris in charge of sports, the Olympic and Paralympic Games and the Seine, told BFMTV.

The head of the Olympic Organising Committee, Tony Estanguet, echoed these comments, telling the French news channel that the “test results from the summer of 2022 were very, very, very encouraging (…) the tests from this summer have shown that we are already at levels that allow swimming”.

Despite these encouraging results, the deputy mayor did say that hazards, such as large storms, could make it so that the river needs to be closed for a few days to be at safe pollution-levels again.

And that’s exactly what happened when test swimming events were held in the summer of 2023 – although some triathlon events were able to take place, others were cancelled because heavy rain resulted in too much polluted water being flushed into the Seine. 

“In this situation, organisers would have a two to three day margin to shift events around”, Rabadan explained, referencing the Olympic and Paralympic Games.

Researcher in microbiology at the University of Paris-Est Créteil, Françoise Lucas, told BFMTV that, for this reason, “we must hope that it does not rain at all in the three days ahead of the Olympics”.

Olympic organisers early in 2024 said that they are confident that swimming events will take place in the Seine and that there is “no plan B”.