Volunteers Uncover River Pollution Data in Cotswolds

When Stuart Pickles started testing the River Isbourne near his home, he expected clean water since the river flows from nearby Cleeve Hill. Instead, he and nine other volunteers discovered pollution levels high enough to shock the entire community.

The group from Winchcombe Green Town has been testing four sites along their stretch of the 14-mile River Isbourne every single week for more than a year. They measure phosphates, nitrates, temperature, and conductivity levels using kits funded by their town council.

Their dedication filled a critical gap. Before these volunteers started their project, no water quality data existed for this section of the river. Now armed with evidence, they're calling on the Environment Agency to investigate.

The results showed worryingly high levels of both nitrates, likely from agricultural fertilizers, and phosphates, which typically come from sewage outlets. Town Council Chairman Jim Mason said the findings were "very disturbing" and may explain why he's noticed declining fish and bird populations along the river.

The Ripple Effect

The volunteers aren't stopping until they gather two full years of data, giving officials a comprehensive picture of the river's health. Their work has already sparked responses from Severn Trent Water, which reported reducing storm overflow spills at Winchcombe Sewage Treatment Works by nearly half between 2024 and 2025.

The water company is investing £160 million across Gloucestershire to improve river health. They noted that phosphorous emissions from their Winchcombe treatment works in 2025 were less than a third of permitted levels, and only two of the fourteen reasons the River Isbourne isn't categorized as healthy relate to their operations.

The town council embraced the initiative because it supports their legal obligation to conserve and enhance biodiversity. The River Isbourne flows through the heart of Winchcombe, making its health essential to the community's environment and quality of life.

What started as neighborhood concern has become a model for citizen science creating real change. These volunteers proved that ordinary people armed with testing kits and determination can uncover environmental issues and hold authorities accountable.

Their weekly trips to the river are building the evidence base needed to protect local wildlife and ensure cleaner water for future generations.