South West Water Reports 17% Reduction in Storm Overflows During Wetter Than Average Year

South West Water Cuts Storm Overflows by 17% – Despite 62% More Rain

South West Water has reduced storm overflow use by 17% and cut spill duration by 25% over the past year, even though the South West experienced significantly higher rainfall than the rest of England.

New figures show the region received 62% more rain than England overall in 2025, according to the Met Office. Almost half, 47%, of all spills happened during the final three months of the year, when the South West saw sustained periods of heavy rain.

Despite those conditions, the company says it has delivered measurable improvements across its wastewater network.

The Key Figures

According to the latest data:

• Total spills reduced by 17%

• Total spill duration reduced by 25%

• More than 8,300 spills prevented through investment and operational improvements

• A 50% reduction in the number of sites spilling more than 100 times annually

• The top five spilling sites reduced by 50% following targeted interventions

• Only 17% of total spill duration is now coastal

• 100% overflow monitoring is now in place across the network

The company says enhanced monitoring means it detects and records short duration spills that other companies may not capture.

Focus on Coastal Waters

Protecting bathing waters remains a stated priority.

South West Water says only 17% of total spill duration is now coastal, and almost all regional bathing waters are rated Good or Excellent by the Environment Agency. It also reports that bathing water spills have reduced over the past five years.

The company has prioritised work at high spilling coastal sites and says it is continuing to focus investment where environmental impact is greatest.

Backed by £760 Million Investment

The improvements form part of a 15 year turnaround plan, supported by around £760 million of investment to 2030. Approximately £760 million is set to be invested over the next five years.

Richard Price, Managing Director of Wastewater Services at South West Water, said:

“We have continued to reduce storm overflow use despite South West England experiencing 62% more rainfall than the rest of England in 2025. Against that backdrop, we have reduced spills by 17% in the last year, and spill duration is down by 25%.

Our focus has been clear – prioritising beaches during the bathing season and targeting our highest spilling sites. We have reduced by 50% the number of sites that spill more than 100 times per year, and our top five spilling sites have reduced spills by 50% following targeted interventions. Since last year, more than 8,300 spills have been prevented as a direct result of investment and operational improvements. This forms part of our 15-year plan, backed by around £760 million of investment to 2030.

We are proud to lead the industry on monitoring and transparency. We measure more spills, more often, with 100% overflow monitoring meaning our data is robust, accurate and fully transparent.

This work reflects our continued focus on protecting bathing waters – a priority our customers have clearly told us is most important to them. There is more to do, but the direction of travel is clear: fewer spills, shorter duration, and focused investment where it matters most.”

Year on Year Progress

South West Water says the 2025 data builds on progress made in 2024, when it was one of only five companies in the sector to reduce spills.

The latest figures are said to show sustained year on year reductions, significant cuts at the worst performing sites, targeted operational interventions delivering measurable results, and enhanced monitoring providing greater transparency.

The company says there is more to do, but that the data shows its plan is working.