Hannah Talbot doesn’t think she could live in north London without the reservoir a short cycle from her flat. The 33-year-old audio producer swims there at least twice a week — more when temperatures creep above 30C — and describes the water as “the lifeblood of London”. But every time a heatwave hits, her relief is mixed with dread.
The popularity of wild swimming in the capital has exploded in recent years, with hundreds descending on a newly designated stretch of the Thames at Teddington during the last heatwave and new freshwater swim sites opening across London. Yet the boom has also exposed the limits of a city still deeply conflicted about how people should use its waterways. Teenagers drown jumping into rivers, sewage alerts force swimmers to check pollution maps, and wildlife campaigners warn of fragile ecosystems being overwhelmed. On Hampstead Heath recently, swimmers have been accused of disturbing nesting swans and cygnets during one of the hottest weeks of the year.
Talbot loves the idea of more Londoners getting into the water, but worries the city has not built enough safe places to swim.
“Trying to get a swim spot in London is like looking for hen’s teeth as soon as the sun comes out and it makes me sad,” she says. “If there were more safe places to swim, there would be less pressure on all the lidos, lakes and reservoirs.”
London’s swimmability might sound like a niche issue relevant only a few weeks a year. But in reality, it touches almost every major pressure point facing the capital: climate change, sewage pollution, public health, urban planning and access to nature.
“The irony is that swimming has never been more popular, yet many swimmers now routinely check pollution alerts before heading to the beach, river or lake,” says Nicky Chisholme, organiser of the annual Big Swim in the English Channel and a campaigner for cleaning up the UK’s waterways.
According to Swim England, open-water swimming has more than doubled over the past decade, with more than four million adults now swimming in lakes, rivers and the sea each year.
The issue has become increasingly political. Last year Sadiq Khan backed ambitions to make London a “swimmable city” by 2034, with City Hall identifying potential new bathing sites on the Thames and in east London waterways. Supporters argue the capital urgently needs more safe places for people to cool off; but critics question whether authorities can realistically expand swimming access while sewage pollution and water safety remain unresolved.
“There’s swimmable and then there’s head-under swimmable”
Flora Blathwayt, Washed Up Cards
So is it actually sensible to strip off the moment it gets hot and jump into the Thames? And what makes a city “swimmable”, anyway? That depends who you ask — and that ambiguity around the phrase itself is part of the problem. For some, it means a river clean enough that you can safely jump in on a hot day; for others it refers to tightly managed, designated spots.
“There’s swimmable and then there’s head-under swimmable,” says Flora Blathwayt, founder of Washed Up Cards, who organises beach cleans across the capital. She swims everywhere from Hampstead Ponds to the Serpentine, but only ever with her head out. “I can’t see that changing anytime soon, much as I’d love it to,” she says.
Most Thames swimmers take the same approach as Blathwayt. “It was like Benidorm but it was fantastic,” says Marlene Lawrence, founder of the Teddington branch of cold-water swimming group The Bluetits, of finding at least 200 people swimming and splashing in her unusual dip spot on the Thames one hot Friday last month.
The stretch of river between Ham and Teddington has been nicknamed “Costa del Ham” for its crowds of after-work swimmers. But the people of Teddington are the lucky few, and becoming a genuinely swimmable city requires more than enthusiasm.
Elsewhere in London, the picture looks very different — because the city’s wild swimming boom is inseparable from the wider decline of public swimming infrastructure. A study by Victorian Plumbing found 67 indoor public pools across the capital have closed since 2015. Outdoor swimming has fared little better. Many of London’s historic lidos disappeared decades ago.
Alan, a podcast producer from Melbourne living in Hackney, says he was shocked by how few open-air swimming pools there are — just a couple of dozen, down from 70 in the 1950s. In Australia, pools are considered basic public services and he believes the UK should be looking to treat them similarly. The UN recently warned that a Super El Niño event could make 2027 the hottest year on record, adding to concerns that heatwaves will become more common in European cities.
The risks of unregulated wild swimming in London
That increasing numbers are turning to unregulated waterways as an alternative is concerning even if it’s far from surprising. Many informal bathing sites are not designed or monitored for large-scale recreational use, and sewage overflows can expose swimmers to bacteria and pollutants, particularly in urban catchments like the Thames Basin. The London Fire Brigade reports that 103 people have tragically drowned in non-suicide-related circumstances over the past five years, and many more report water-related illness from swimming in unsafe lakes, rivers and streams every year.
It’s not just sewage that makes these bodies of water potentially unsafe. Shipping, strong currents, stormwater overflows, tides and hidden hazards beneath the surface can all create additional risks — which is why education is arguably as big a part of the solution as access, says Lawrence. “Lots of people turn up to our section of the river and say, ‘Great, but where’s the beach?’” She ensures she teaches all new members about checking the temperature, the river flow, possible sewage spills before they join a Bluetits session.
Greater education is needed regarding wildlife and fragile ecosystems too, whether it’s taking care not to disturb the swans nesting on Hampstead Heath or the seals, eels and seahorses in the tidal part of the Thames.
“Access to clean, swimmable water in London still divides along demographic lines”
Dr Miriam Burke, East London Waterworks Park
Dr Miriam Burke is the CEO of East London Waterworks Park, a campaign to turn a 14-acre plot of land in Waltham Forest into an “inclusive”, community-owned biodiverse park with wild swimming ponds. She says Hackney Beach is a perfect example of why London’s swimmability is as much a question of social justice as environmental justice.
“The communities living closest to the River Lea are among those with the least access to green and blue space, and the least representation in the spaces that do exist,” she says. “Access to clean, swimmable water in London still divides along demographic lines, and that’s a structural problem, not a cultural one.” Burke agrees with other campaigners that the solution is infrastructure and funding to support wild swimming practices safely, equitably and sustainably — which means not just looking at success stories like Teddington but less affluent spots like the rivers Lea and Roding in east London, where locals are doing their best to tackle sewage and road runoff to boost swimmability.
London architect Chris Romer-Lee is the co-founder of Swimmable Cities & Future Lidos. He believes London has been a swimmable city for some time, but that it’s only now that we’re feeling the pinch with not enough facilities. The recent nature ponds incident on Hampstead Heath “shone a bright light on just that,” he says. “How are we going to ensure the less well-off manage the expected increases in heat within our cities?”
Romer-Lee believes Britain still treats swimming as a lifestyle luxury rather than a public health necessity — despite mounting evidence that regular access to water improves wellbeing and reduces pressure on the NHS. If London fails to adapt its waterways and public spaces for a hotter future, “there will be more tragic drownings, more people dying from heat related illnesses, more people leaving our cities and poorer wellbeing”.
Kirsty Davies from Surfers Against Sewage says Londoners increasingly need to look to other European cities to understand what a “swimmable city” could look like. Paris invested €1.6bn in cleaning the Seine ahead of the 2024 Olympics and has now opened designated river swimming sites and floating pools in the city centre. Copenhagen has embedded harbour baths across the city. Whether London can realistically follow suit remains contested. But Romer-Lee believes London does not need to transform the Thames to become swimmable.
What would a truly ‘swimmable’ London look like?
It needs a mix of designated bathing areas, floating pools and accessible waterfronts — similar to models already operating in Paris, Copenhagen and Berlin — to ensure people have safe ways to enter the water without overwhelming fragile ecosystems or commercial waterways. “I’m interested in how our new swim sites can offer special sessions that make water more inclusive: kids only, Muslim women only, scuba lessons, kayak training for over-sixties,” he says.
For Romer-Lee, this is the more fundamental question: not just whether London can become swimmable, but what kind of “swimmable” it is trying to become. “Just because the central London section of the river is tidal, fast-moving and a busy commercial waterway doesn’t mean we can’t safely have floating pools,” he says. “It’s nonsense to suggest this will encourage more people to jump into the central stretch of the Thames.”
“A truly water-connected city is one where water is not treated as a hazard to be fenced off”
Ben Seal, Paddle UK
Floating saunas like TEMZ in Teddington, paddleboarding clubs and other activities are already reshaping how Londoners use the river, but they remain patchy and underprovided for. “In much of central London, the Thames is hidden behind Victorian embankments, railings and defensive architecture designed to keep people out,” says Ben Seal of Paddle UK. “A truly water-connected city is one where water is not treated as a hazard to be fenced off.”
Khan was originally told it would take 25 years to turn air quality around in London and he managed it in eight — and Romer-Lee is confident the same can be done for polluted waterways.
Wild swimming events like a new 3km race King of the Thames in Hampton Court later this month show the cultural momentum is there. The question is whether London’s infrastructure, politics and waterways can evolve quickly enough to meet it safely. Because for all the city’s talk of becoming “swimmable”, the Thames is still both London’s lifeblood and its dumping ground — a source of escape and connection, but also a reminder of how unprepared the capital remains for a hotter future.
