South West Water has cut storm overflows by 17% despite significantly higher rainfall across the region in 2025, according to newly released performance data.
The utility reported a 25% reduction in total spill duration compared with the previous year, even as South West England experienced 62% more rainfall than England overall, based on Met Office figures.
Storm overflows reduced during sustained wet weather
Storm overflows reduced across the wastewater network despite prolonged periods of heavy rainfall, with almost half (47%) of all spills recorded during the final three months of the year.
South West Water reported:
- 17% reduction in total spills
- 25% reduction in total spill duration
- More than 8,300 spills prevented through investment and operational changes
- 50% reduction in sites spilling more than 100 times annually
- 50% reduction in spills at the five highest-spilling sites
- Only 17% of spill duration now occurring at coastal locations
- 100% overflow monitoring coverage
Richard Price, Managing Director of Wastewater Services at South West Water, said the improvements form part of a longer-term investment programme focused on reducing environmental impact, particularly during the bathing season.
Bathing water protection remains a priority
Protecting bathing waters has been prioritised within the company’s operational strategy. According to the utility, almost all regional bathing waters are currently rated Good or Excellent by the Environment Agency.
The company stated that only 17% of total spill duration is now associated with coastal overflows, reflecting targeted interventions at high-spilling sites.
The reported improvements form part of a 15-year programme backed by approximately £760 million of investment to 2030. The utility noted that enhanced monitoring means short-duration spills are more consistently detected and recorded.
For more coverage on wastewater performance and storm overflow management, visit our Wastewater section.
