Record number of UK citizens expose crisis in UK waterways
28th May 2025
In April, thousands of people joined our latest Great UK WaterBlitz, the UK’s largest freshwater campaign to date – the results revealed that the majority of the UK’s freshwaters are suffocating under relentless pollution.
During the Great UK WaterBlitz, which took place between 25 – 28 April, 7,978 citizen scientists have tested 4,017 freshwater sites for nitrates and phosphates, revealing that 66% of them show unacceptable pollution levels. The data signals no improvement from the two previous WaterBlitz
events, which showed 75% (Summer 2024) and 61% (Autumn 2024) of sites failing to meet basic ecological standards.
The challenges facing UK rivers are being further compounded by the escalating impacts of climate change. This year’s exceptionally dry spring has led to alarmingly low river levels across the country. This lack of water in river intensifies the concentration of pollutants, making already stressed aquatic ecosystems even more vulnerable. As climate change continues to bring more frequent and intense periods of drought, the delicate balance of our freshwater environments is increasingly threatened, underscoring the urgent need for action to reduce pollution.
The most recent data collected as part of this campaign has laid bare the ongoing water quality crisis facing the UK. England’s rivers are the most polluted, with 74% of sites showing poor water quality. The Thames and Anglian River basin districts are among the worst affected, with 86% of samples indicating excessive nutrient pollution, primarily from phosphates and nitrates.
Meanwhile, Northern Ireland’s Neagh Bann River basin emerged as a rare bright spot, reporting the best water quality in the UK.
In addition to the UK-wide nutrient pollution testing, 300 Locations were also tested for E coli. 24% of locations tested had E. coli levels too high for safe swimming, pointing to serious public health risks. Scientists also observed a positive correlation between E. coli and phosphate levels, suggesting links
to wastewater mismanagement.
“The latest WaterBlitz results paint a stark picture of the persistent poor health of our UK rivers,” said Dr Sasha Woods, Director of Science and Policy at Earthwatch Europe. “However, this very data, revealing the extent of the challenge, is also a source of immense hope. It has been gathered by an ever-growing army of citizen scientists – people who care deeply about their rivers. Their dedication is a wake-up call to Government and regulators to act now.”
Sasha goes on to say: “We’re swimming in dying rivers. While E. coli levels might be within ‘safe’ swimming limits in most locations, this hides a deeper ecological collapse. Our rivers are suffocating under relentless pollution – sewage, tyre particles, fertilisers – and this data is proof. It’s time to act.”
The findings will be shared with national agencies, local authorities, and policymakers to push for urgent systemic changes in wastewater treatment, land management, and river protection.
Despite the grim data found in this report, the campaign has ignited a powerful public movement. Thousands of everyday citizens, armed with water testing kits and a passion for protecting nature, have become the UK’s largest network of freshwater watchdogs.
You can read the full results in our Great UK WaterBlitz report here: Great UK WaterBlitz Spring Report 2025 – Earthwatch Europe
Thank you to the WaterBlitz funders and supporters
We are incredible grateful to our generous funders: Funding Circle, DAERA, Barnsbury Charitable Trust, Big Give, CaSTCo, Oakdale Trust, The Tomoro Foundation and The WFH Foundation.
Also a big thanks for the fantastic support from the following organisations: National Trust, The Rivers Trust, Surfers Against Sewage and the WI.
