Millions are plunging into Britain’s lakes and rivers for mind and body wellness — but outdated regulations and polluted waters mean swimmers are facing risks they never signed up for, as Tamara discovered firsthand.
Last summer, I reunited with my family for a holiday in the Lake District, Cumbria. These days, it’s rare to get us all in one place. Much to our parents’ dismay, we’re scattered overseas and at opposite ends of the country. So when we do manage to cajole everyone together, the occasion is packed with more tea rooms than you would think possible, and all manner of outdoor activities.
On this holiday in particular, inspired by the famed water all around us, my sister and I made a whimsical pact: we would take a wild dip every single day.
Come rain or shine we chased every bit of enticing open water we could find. A brisk plunge into the midnight-blue Stickle Tarn after scrambling the unnerving Jack’s Rake, a splash at Low Water on the Old Man of Coniston Horseshoe walk, and immersions among the reeds and curious ducks of Elter Water and River Brathay.
But after only a few days, we were floored by an awful fever and sickness bug.
My sister, usually as tough as they come, slept feverishly for two days straight, not even rousing for food. And I endured what can only be described as a full body cleanse. We’re not the sickly type – usually outdoors getting grubby year-round, rarely ill more than once a year – but this time, we were completely struck down.
What began as a joyful reconnection with nature and family turned into a bit of a wake-up call. Whilst we weren’t exactly on our deathbeds, it was unexpected and highly unpleasant. That holiday, my eyes were opened to the invisible threats of swimming in our natural bodies of water, and not to mention the repercussions of poor water quality on our suffering wildlife.
Britain’s Wild Swimming Boom
Wild swimming isn’t a niche anymore, it’s a mainstream hobby. Estimates suggest that around 7 million Brits now swim year‑round in rivers, lakes, seas, and lidos.
I find it amusing when people allude to wild swimming being a new trend. People have always swum outside for wellness and the simple joy of it. It’s just that participation has surged dramatically recently, by as much as threefold since 2019.
People’s interest in the topic is growing too. A whopping 84% of respondents in a survey said that summer wild dipping was of interest to them, and 75% in winter plunges.
The hobby is also deeply rooted in wellness culture: nearly 70% of wild swimmers say it’s essential or very important to their mental health, and 43% cite health and wellbeing as their primary motivation (source).
Scientific research even backs up these sentiments, suggesting that cold-water immersion helps with mood, stress reduction, immune function, and sleep – so much so that the UK Government is exploring “nature prescriptions” for certain conditions.
But isn’t it incredibly ironic that the very health benefits wild swimmers are seeking are becoming outweighed by the health risks posed by unclean water?
Regulation Hasn’t Kept Up with Popularity
Despite millions taking the plunge, our water monitoring systems simply haven’t kept pace. It’s quite frankly an outrage.
A government analysis recently revealed that 3,347 water recreation sites are actively used across England’s rivers, lakes, and coasts – 1,727 for swimming alone – but only 451 of those are officially designated bathing sites and therefore tested for pollution. And that testing is only occurring during a short bathing season.
That means over 80% of swimming locations lack regular water quality monitoring, exposing swimmers to hidden risks.
In Scotland, the situation is just as worrying. Almost 60% of popular wild swimming spots are contaminated with human and animal waste during the summer, with E. coli levels over 20 times the safe limits in places like Ayr’s South Beach and Fisherrow Sands.
In April 2025, the Times also shockingly reported that sewage is dumped in Scottish waters every 90 seconds. Let that sink in – by the time you’ve read this article, it’s probably happened at least three times already!
And if you’re picturing balaclava-clad men arriving at the dead of night to pump truckloads of crap into a lake, that’s not the case. Human waste in water is actually predominantly due to infrastructure and policy issues: antiquated sewer systems and poorly monitored sewer overflows.
The Hidden Risks: What Polluted Waters Do to Our Bodies
For most wild swimmers, the greatest perceived danger is drowning. Yet in truth, one of the biggest risks comes from what we can’t see: waterborne pathogens.
When pollution seeps into our rivers, lakes, and seas, it brings with it a cocktail of bacteria, viruses, and parasites that can cause illness ranging from an unpleasant stomach bug to life-threatening disease.
The most common culprits are E. coli and norovirus, both of which can trigger severe diarrhoea, vomiting, fever, and dehydration. Other nasties include cryptosporidium and giardia, parasites that lead to prolonged bouts of gastroenteritis, and blue-green algae (cyanobacteria), which can cause rashes, nausea, liver damage, and in some cases be fatal to dogs and livestock.
The risks aren’t theoretical either. At the Hampton Court Swim back in 2012, where competitors took on the River Thames, 50% of participants fell ill in the days afterwards. A third needed to see a GP, four were hospitalised, and tests showed one in ten had a confirmed gastrointestinal infection.
More rarely, swimmers can contract leptospirosis (Weil’s disease), a bacterial infection spread through rat urine that lurks in stagnant or slow-moving water – delicious! While cases are uncommon, the UK Health Security Agency recorded 52 infections in England in 2022, with symptoms ranging from flu-like fatigue to organ failure. The fatality rate can be as high as 1 in 20, making it a risk that swimmers cannot afford to ignore.
And though statistics are often bundled under “open water incidents,” some tragedies are directly linked to water quality.
In Scotland, for instance, environmental campaigners have pointed to unexplained deaths of dogs and suspected links to algal blooms and sewage overflows as stark reminders that contaminated water is not just an inconvenience – it can kill.
The Data Gaps Leave Swimmers Vulnerable
Image credit: Author.
On my holiday to the Lake District, I admit that checking the water quality didn’t even cross my mind. In fact, I would have had no idea where to even start looking. And that’s part of the problem: for most wild swimmers, the information either doesn’t exist or is buried in government websites few people know about.
On the whole, risk information is inconsistent and often absent. Across Scotland, wild swimmers generally show strong risk awareness but find generic guidance unhelpful — without location-specific data, people tend to ignore or misjudge hazards, including polluted waters.
There are some places to look if you know where to dig though.
The Environment Agency publishes water quality data for England’s official bathing waters (around 451 sites), while SEPA (Scottish Environment Protection Agency), Natural Resources Wales, and DAERA (Northern Ireland) provide similar seasonal testing results.
Campaign groups like Surfers Against Sewage also run real-time alert services and apps, warning swimmers when sewage discharges occur.
But all these resources only cover officially designated bathing waters, and often only during the summer season – leaving thousands of rivers, lakes, and beloved wild swim spots completely unmonitored the rest of the year.
So, How Can The Narrative Be Changed?
Wild swimming isn’t going anywhere. Britain’s wild swimming boom is only set to grow, but the infrastructure to safeguard health and nature lags behind, and needs a rapid upgrade.
Achieving Year-Round Monitoring Through Nominating Bathing Water Spots
First, we need year-round monitoring, not just a handful of months in summer, and certainly not at only a fraction of the places we’re actually swimming.
One practical way that anyone can get involved in that is through official bathing water designation. Local communities, campaign groups, or councils can apply directly to DEFRA to have a stretch of river, lake, or coastal area recognised as a bathing water.
The main requirement is to prove that the spot is genuinely used for recreation – think numbers of swimmers, paddle boarders, or kids splashing about, backed up with surveys, testimonials, and photos. Once a site is designated, it must be monitored each bathing season with results published online – an important first step toward the case for year-round testing.
Improving Information Flow of Water Quality
Then there’s the need for clear, location-specific alerts, not vague warnings buried on clunky websites but real-time updates on sewage spills, algae blooms, or rain-related risks, delivered where people are: on their phones, at the water’s edge, and in the community groups that spread word faster than official channels ever could.
Advocacy Through Citizen Science
Finally, swimmers themselves can be part of the solution. Citizen science projects, whether they’re testing kits, crowd-sourced maps, or simply reporting what you see, empower us to protect the very waters we love.
After all, who better to keep watch than the people diving in every day?
A wild swim should leave us glowing, not groaning. And if we can get that balance right, Britain’s wild waters can remain what they ought to be: a lifeline for both people and wildlife, in sickness and in health.