A high-profile project to clean up Paris's iconic river seems to be paying dividends, but its success has drawn a critical eye to efforts to stop sewage dumping in UK's waterways.
France has committed to making the once-polluted Parisian river safe to swim in, in time for the next Olympic games in 2024, and has poured €1.4 billion (£1.2 billion) into solving its pollution problem. The city has made a long-term commitment too - with plans for swimming spots for residents and tourists alike which will remain long after the games have ended.
But years on from its Olympic bid, how is the clean-up tracking - and why are environmentalists drawing parallels between swimming in the Seine, and the Thames?
Why does Paris want to clean up the Seine?
The 777-kilometre Seine is one of the world's most iconic rivers, particularly the stretch that snakes through the streets of Paris - flanked by iconic buildings like the Eiffel Tower, the Louvre, and Notre Dame Cathedral. But like many of Europe's major rivers, it had become badly polluted.
Paris will host the 2024 Olympic games, and Euronews reports two swimming races are scheduled to be held in the river, between the Alexandre III Bridge and the Eiffel Tower off the 7th arrondissement.
However, swimming in the Seine was banned in 1923 due to high levels of dangerous bacteria like e.coli, and pollution. In heavy rain, sewers in the capital overflow into the river, contaminating it further. People caught breaking the rules by swimming are subject to fines.
As part of its 2016 bid to host the Olympics, the city announced the €1.4 billion (£1.2 billion) plan to fix the problem in time for the games, Bloomberg reports. Measures to do this includes building a 50,000 cubic-metre retention pond to prevent sewage overflow.
The city has said it is committed to the cause long-term as well, and in 2025 after the games are over, it plans to build public swimming pools along the riverbanks - separated from boat traffic - for everyone to use.
How is the clean-up progressing?
A photo on the cover of French daily newspaper Le Parisien on Tuesday (2 May) featured a woman swimming in the river, and drew international attention back to the clean-up.
Paris City Hall said the Seine's water quality has been improving since work began, and more species of fish have appeared, sports publication Inside the Games reports.
But Le Parisien reported many Parisians still had some way to go before they would take the plunge and swim in the Seine themselves, after years of considering it dirty and polluted. “There is a lot of educational work to be done so that people reclaim the Seine and integrate that it is swimmable and that we comply with regulations", said Pierre Rabadan, deputy mayor of Paris for sport and the Seine.
"It is necessary, for example, to explain why the Seine is often a little brown. There is river traffic, the passage of boats stirs up the mud." The city would “communicate as widely as possible on the results of the analysis of the water of the Seine, because it is also an element of credibility", he continued. The results are displayed in real time at the Sewer Museum of the City of Paris.
Why are environmentalists comparing it to the UK?
In response to La Parisien cover, Northern Irish singer Feargal Sharkey - who has become a figurehead in the fight to stop water companies discharging sewage into UK rivers - Tweeted: "What a contrast".
"Paris spends €1bn to clean up the Seine so people can go swimming in it, while last year alone @thameswater spent 7,000 hours dumping sewage into 31 of London's rivers, all of which ends up in the Thames," he wrote.
Sharkey was referring to the UK's ongoing issue with sewage spills even during warm and dry weather, which is not permitted under the Environment Agency rules, many of which affect The Thames - London's similarly iconic river. The overflows have left dozens of beaches and waterways across Britain unsafe to swim in, much to the fury of residents and environmentalists alike.
But water firms who do this may soon fall foul of the law. The government announced last week water companies will now face legally binding targets to cut sewage discharges into the UK’s rivers.
Environment Secretary Therese Coffey said the government would introduce legislation to put previous plans to reduce storm overflows on a “new legal footing”. In a written statement to Parliament, Coffey said: “Through the Environment Act 2021, we will legislate for a clear target on storm overflow reduction in line with our plan.
“A clear, credible and costed legally binding target will add to our transparent and determined approach to solve this issue, whilst keeping consumer bills low. This will also be backed by existing separate interim targets for bathing waters and our most precious habitats," she said.
The government’s Storm Overflows Discharge Reduction Plan, published in August 2022, aims to eliminate sewage dumping by 2050 outside of unusually heavy rainfall, while cutting discharges close to “high priority” areas by 75% by 2035 and 100% by 2045.
Coffey said: “I have been unequivocal on this issue. Water companies need to clean up their act – and they need to cover the costs... But the hard truth is that however much we all want to see this fixed immediately, the scale and complexity means there is no way that we can stop pollution overnight. To suggest otherwise is dishonest.
“I am using the full force of my powers to make sure that we stop the damage caused by storm overflows as quickly as possible. That includes our plans today to put our costed and credible target on a new legal footing.”
But The Rivers Trust accused ministers of a “lack of ambition and clarity for the sector”. “Far from revolutionising the sewer system, as the plan claims, this plan aims to claw its way back to what should have already been ‘business as usual’ by 2050 – with sewer overflows operating only during exceptional rainfall events by that time,” the charity said.
Advocacy and engagement director Christine Colvin added: “The requirement for this plan in the Environment Act gave Government a great opportunity to right the wrongs on weak regulation and get on the front foot... It should have presented an open goal for a fresh start to stop sewage pollution in my lifetime. Instead, they’ve scored an own goal.”