Volunteers needed to help uncover the health of Yorkshire's rivers this September
Almost one in four river samples taken in Yorkshire's Derwent and Aire catchments showed poor water quality during the Great UK WaterBlitz in April 2026, as Yorkshire Wildlife Trust’s Rivers to Reef partnership project calls for more volunteers to help build a deeper understanding of the health of Yorkshire's rivers.
Nearly 200 water samples were collected by volunteers across two of Yorkshire's major river catchments during April, as part of Earthwatch's national water sampling campaign. Results revealed a mixed picture of the county's rivers and highlighted the importance of continued citizen science.
Working with partners at the Aire Rivers Trust and the Yorkshire Derwent Catchment Partnership, and supported by Yorkshire Water, Rivers to Reef is creating a movement to protect rivers from their source in the hills and moorlands, to the North Sea. The programme expands citizen science in Yorkshire through standardised water quality monitoring, community litter surveys and support for the Great UK WaterBlitz which brings volunteers together twice a year to collect water samples and build a nationwide snapshot of river health.
In April, volunteers collected 197 water samples across the Aire and Yorkshire Derwent catchments, testing for nitrates and phosphate, two nutrients that provide valuable insight into river health. While nutrients occur naturally and are essential for healthy ecosystems, excessive levels of nitrates and phosphates can indicate pollution from agricultural runoff, storm overflow discharges, misconnections and urban development. Elevated nutrient levels can fuel excessive algal growth, reducing oxygen levels and damaging habitats that wildlife depends on.
The results showed that 60% of water samples achieved a good overall nutrient rating, while almost 25% samples were classified as poor. Volunteers collected 163 samples across the Aire catchment and 34 samples across the Yorkshire Derwent catchment, providing valuable insight into water quality across both river systems.
Yorkshire's rivers drain almost 20% of England's landmass into the Humber Estuary, the largest freshwater input into the North Sea and an internationally important site for wildlife. Yet the Humber's ecological condition has remained classified as "unfavourable" for more than a decade, with habitats including saltmarsh, seagrass meadows and shellfish beds continuing to decline.
Rivers to Reef is tackling these challenges by combining scientific monitoring, policy work and community action. Through biannual Great UK WaterBlitz events, volunteers help identify pollution hotspots and build a clearer picture of river health across Yorkshire's catchments.
Ana Cowie, Marine Projects Manager at Yorkshire Wildlife Trust, said:
"The Great UK WaterBlitz is giving us an invaluable snapshot of the health of Yorkshire's rivers, but we need more boots on the ground to build an even clearer picture.
"The April results show that while many of our rivers are in good condition, there are still areas where nutrient pollution is affecting water quality. Every sample collected helps us identify pollution hotspots and better understand what's happening across our catchments.
"We're particularly keen to recruit more volunteers in the Yorkshire Derwent catchment so we can build a more balanced dataset and compare the health of both river systems in greater detail. Whether you're an experienced volunteer or completely new to citizen science, taking part is quick, simple, and makes a real difference."
Clare Beasant, River Health Improvement Manager at Yorkshire Water, said:
“Healthy rivers and the seas that they feed depend on strong connections between people, organisations, and the watercourses that flow through communities.
Combining local knowledge with scientific monitoring means that we can build a stronger understanding of our catchments, and better target actions that will deliver long-term improvements for river health.”
The next Great UK WaterBlitz takes place between 18th - 21st September 2026, when volunteers across the Yorkshire Derwent and Aire catchments will collect water samples over the same weekend to create a county-wide snapshot of river health. No previous experience is needed, with free testing kits and guidance provided.
People can sign up to take part in September's Great UK WaterBlitz and read the full report from April's survey at ywt.org.uk/rivers-to-reef .
Earthwatch