Too Hot, Too Crowded — 4 Ways To Make London More Swimmable

If you attempted to swim in London this past month, you probably encountered most (if not all) of the following — long queues, overcrowding and, sadly, public disorder. Parliament Hill Lido has been forced to close due to anti-social behaviour twice since May, whilst London's other swim spots have been stretched to absolute breaking point.

The solution is obvious — we need more swim spots in London. In particular, I believe we need more places where people can swim for free.

Parliament Hill Lido during the heatwave (pic taken by one of our social swimmers).

Yesterday, we became an official signatory to the Swimmable Cities Charter, joining over 250+ brands & organisations in 115+ cities worldwide on a mission to make urban waterways swimmable & accessible to all people. (Highkey, I am v proud of this.)

The question, then, is how do we make London more swimmable? Here are 4 solutions, drawing on successful examples from cities around the world.

1) Stop pollution at the source

(Not very sexy, but it's foundational.)

One of the major causes of pollution in London's waterways is combined sewage overflows (CSOs). This is where excess untreated wastewater is intentionally discharged from the sewer network to prevent flooding during periods of heavy rain.

This can be massively reduced by upgrading sewage & treatment infrastructure. In 2025, the River Seine in Paris was was officially reopened to swimmers for the first time since 1923, following major infrastructure upgrades designed to reduce pollution for the 2024 Olympics. Similar upgrades in Copenhagen made its harbour swimmable in 2002.

The best bit? London has already (and recently) upgraded its sewage system. That's right, the Thames Tideway Tunnel opened in 2025, preventing 95% of the sewage spills that previously entered the River Thames. So we've already taken a massive (and expensive) step in the right direction — but it's what comes next that counts.

2) Designate more bathing sites (and stop the government quietly gutting the system)

In May this year, a stretch of the Thames near Teddington was officially designated as "bathing water" — triggering mandatory water testing, and obliging Thames Water to investigate & remedy sources of pollution.

The bathing site at Teddington (also snapped by one of our social swimmers).

This is a vital step in creating more swim spots, however it is not a silver bullet. The River Wharfe at Ilkley was the first river to be designated as a bathing site in 2020, yet it has tested "Poor" every year since then. The point is that designation must be followed by concrete action & investment to reduce pollution, otherwise it is pointless.

More pressingly, the government has recently amended these regulations to introduce a new feasibility test for any new proposed bathing site. In effect, this allows the government to say that a site is too polluted to be cleaned up, completely neutering the purpose of the regulations.

Surfers Against Sewage is (as always) doing fantastic work by bringing a legal challenge against these changes (joined by River Lim Action, a group who successfully campaigned for the re-designation of Church Beach in Dorset).

3) Build more swim spots

It feels like there are so many missed opportunities for new swim spots in London. Sea Lanes recently opened a floating lido in Canary Wharf, which looks pretty cool, but at the same time the planned reopening of Valentines Lido has been put on pause.

Sea Lanes, Canary Wharf.

I'm shooting from the hip here, but I've always thought St Pancras Basin (just opposite Gasholder Park near King's Cross) would be a banging swim spot. There is also the proposed East London Waterworks Park in Walthamstow, which I've written about previously.

In Rotterdam — where Swimmable Cities held their 2025 summit — they've turned the Rijnhaven, previously an industrial port, into a floating (and commercially thriving) pontoon swim park. And in New York, a group called + POOL are piloting a design for a floating pool that would filter river water to a swimmable standard.

Plenty of innovative ideas out there, we just need to get creative.

4) Reframe swimming as a right

This is more of a vibes point, but in many ways the most important.

In Australia (where I grew up), the fundamental assumption is that you have a right to swim (for free!!) in any natural waterway. It might not always be the best idea (sharks, jellyfish, strong currents, etc.), but if you wanted to you could.

The same applies in many European cities. In Switzerland for example, swimming in city rivers is a way of life that is permitted by default. Basel is one of the best examples of this, with swimmers using the currents of the Rhine to commute through the city (using their "Wickelfisch" swim bags to keep their possessions dry).

Unfortunately, here in London (and the UK more broadly), the right to swim is not the starting assumption.

This really matters. For one, it enables a lot of excuse-making around pollution and a failure to invest in proper swim infrastructure. After all, if swimming is characterised as "dangerous" and "not allowed", then the fact that the waterways are too dirty to swim in is by-the-by. It also fuels a prohibitionist mindset that prioritises safety over all other considerations, which in my opinion is sad.

So what can we do?

The truth is, every positive change I've mentioned above has only happened because there was a culture & community behind it.

Teddington acquired its bathing water designation because it was being swum in regularly by groups like the Teddington Bluetits. In Switzerland it is simply unfeasible for city rivers to be rendered un-swimmable, as it is such a core part of peoples' everyday lives.

You can't legislate culture — you have to build it. Join a swim club (we run one at the West Reservoir + there are loads of others like Black Women Swimming, Chilly Dippers, Girly Dips and Queer Swim). Get involved with organisations like Swimmable Cities, Surfers Against Sewage and Thames21. Grab your mates and go for a swim, anywhere.

Thanks for coming to my TED Talk — see you for a social swim soon.

Sax x

Bobbing Along #17