France, explained.

Artwork along the River Seine, Paris. The Opening Ceremony of the Paris 2024 Olympic Games takes place on Friday 26th July, along the River Seine. Picture date: Monday July 22, 2024. (Photo by Mike Egerton/PA Images via Getty Images)

Artwork along the River Seine, Paris. The Opening Ceremony of the Paris 2024 Olympic Games takes place on Friday 26 July, along the River Seine. Picture date: Monday 22 July 2024 (Photo by Mike Egerton/PA Images via Getty Images)

Rain in the Seine would be an Olympic-sized pain

But the effort to clean up the famous waterway in Paris could hold international lessons.

Neeraj Singh Manhas

24 July 20242 min read

Paris will be praying against rain. Despite extensive efforts to clean and prepare the River Seine ahead of the 2024 Olympics, due to commence on Friday, concerns about water quality persist. A heavy downpour could leave the river unsafe for athletes in several high-profile aquatic events planned during the games.

Recent tests have shown varying levels of bacteria in the Seine, where swimming has been banned since 1923 due to the high pollution levels. But since bidding for the Olympics hosting rights in 2015, environmental agencies and city officials have been working tirelessly to ensure the river’s safety, implementing measures such as improved sewage treatment and regular water quality monitoring. Authorities have invested around €1.4 billion with the aim to make the river safe to swim for Olympic events such as the triathlon, para-triathlon, marathon swimming, and to host a distinctive opening ceremony.

Paris mayor Anne Hidalgo leapt into the famed waterway last week for a dip to prove that the famous river had met stringent safety standards.

Paris Mayor Anne Hidalgo waves before swimming in the Seine on 17 July (Joel Saget/AFP via Getty Images)

Water quality is a challenge in major cities around the world. Storm water, chemical pollution or waste spills often lead to pollution. The potential health risks associated with swimming in contaminated water include gastrointestinal illnesses and skin infections from microorganisms. For Olympic athletes who invest years of training for a shot at gold, illness can spoil dreams and livelihoods.

The clean-up for the Seine involved constructing massive rainwater catch basins and tunnels to prevent untreated sewage from overflowing into the river during heavy rains. Treatment plants have also been modernised for water purification. As environmental scientist Ian Wright observed, this followed efforts in other European cities where river swimming is now common such as Copenhagen, Berlin and Vienna, and the goal for the Seine was to reduce bacterial contamination by at least 75 per cent.

The hope is still for a great event and that the river clean-up for the Olympics might hold lessons internationally.

Cleaning the Seine after years of degradation proved a challenge. Greater Paris is home to 12 million people with the city surrounded by heavy industry. But recent rains in Paris have seen bacteria levels spike. A weather data analysis by news agency Associated Press showed that this year Paris has had the second-most days with rain since 1950. Of all the luck.

The hope is still for a great event. And the river clean-up for the Olympics might hold lessons internationally. The focus on rigorous water quality monitoring and innovative purification techniques could be deployed elsewhere, along with floating wetlands and bio-remediation projects to help clean waterways. Drones equipped with sensors can patrol the water, identifying and addressing pollution sources swiftly. The success of efforts in Paris will not only affect the outcome of the 2024 Olympics but also set a precedent for future games in remediating the environment.

And the effort draws on history, too. This will not be the first time the Seine has been used for Olympic swimming. The 1900 Paris Olympics held seven swimming events in the river. Let’s hope that after these games the swimming continues.