South West Water has been identified as the worst-performing water company in England in terms of environmental impact, according to an analysis by the environmental campaign group Friends of the Earth. The company, which serves Devon, Cornwall, Dorset, and Somerset, was found to have the highest volume and duration of sewage discharges among its peers.
The organisation evaluated water companies across six key criteria: the frequency and duration of sewage spills, water quality at designated bathing sites, pollution incidents and warnings at these sites, the severity of sewage pollution at bathing waters, the proportion of rivers failing to meet good ecological status, and the affordability of customer bills.
South West Water ranked among the three worst performers in four of these categories. It recorded an average annual total of approximately 574,323 hours of sewage discharge events since 2024, outpacing second-place Severn Trent by nearly 200,000 hours. Furthermore, its bathing sites experienced the greatest number of pollution incidents and warnings, with 666 events documented in 2025 alone. The company oversees 157 official bathing locations, where the Environment Agency monitors water quality during bathing seasons to safeguard public health.
In response, South West Water acknowledged the challenges but emphasized ongoing efforts to improve conditions. A company spokesperson highlighted that it manages over one-third of England’s designated bathing waters, making water quality a central focus. They reported a 17% reduction in storm overflow spills and a 25% decrease in spill duration over the past year, despite experiencing significantly higher rainfall levels. The spokesperson also noted that South West Water is on track to comply with the new Environment Act standards for bathing water quality by 2030, five years ahead of the required national deadline.
Severn Trent and Yorkshire Water were ranked second and third, respectively, but did not match South West Water’s level of sewage spill duration or number of pollution reports.
The findings underscore ongoing concerns about water quality and environmental management in parts of southern and southwestern England, prompting close scrutiny of water companies’ efforts to reduce pollution and protect ecosystems.