Raw Sewage Discharges in England: Nearly 300,000 Spills Despite Drought Conditions

Raw sewage was discharged into England’s rivers and seas almost 300,000 times in 2025, despite one of the driest springs in over a century and the warmest, sunniest year on record.

According to data from the Environment Agency, water companies released untreated sewage 291,492 times through storm overflows—systems intended only for extreme weather conditions.

Storm overflows are designed to prevent system overload during heavy rainfall. However, their widespread use in dry conditions raises serious environmental concerns.

In 2025:

• Average spills per overflow dropped to 20.5, down from 31.8 in 2024
• Total discharges fell by 35% compared to the previous year

While this reduction may appear positive, experts warn that the figures remain unacceptably high—especially given the lack of significant rainfall.

The total duration of sewage discharges decreased significantly:

• Down to 1.8 million hours in 2025
• Compared to nearly 4 million hours in 2024

Some water companies achieved reductions of 60–70%. However, campaigners highlight that discharge durations are still nearly 1 million hours higher than in 2018—pointing to long-term underinvestment in water infrastructure.

Environmental Experts Warn of Illegal and Harmful Discharges

Environmental groups have raised alarm over the continued use of storm overflows during drought conditions.

Richard Benwell, CEO of Wildlife and Countryside Link, emphasised that sewage spills remained widespread despite dry weather.

“When sewage is pouring out even in a dry year, you really know the system is broken,” Benwell said. “These aren’t stormwater overflows; they’re all-weather waste pipes. Rivers, lakes and seas should not be pressure valves for pollution. Any sewage in our waters is too much.

“This is what systemic failure looks like: multiple sources of pollution, weak oversight and no single body taking responsibility for the health of our waters.”

Michelle Walker of The Rivers Trust stated that many of these discharges were likely illegal and posed serious risks to both ecosystems and public health.

“We expected to see a lower number of untreated sewage discharges in 2025 as it was such a dry year, but this should not be mistaken for progress,” Walker said. “Far too many of these [discharges] will be happening on dry days and therefore be illegal.

“The impact of those discharges will be even worse when rivers are running low. Each discharge will be more concentrated, more damaging and more dangerous for already stressed ecosystems. At the same time, more people will be taking to rivers and seas to cool down on hot days, putting public health directly at risk.”

Drought Conditions and Hosepipe Bans Across England

Large parts of England experienced prolonged drought in 2025, with four water companies enforcing hosepipe bans.

This makes the scale of sewage discharges even more concerning, as storm overflows should only be used during periods of heavy rainfall—not water shortages.

Water companies acknowledged that dry weather contributed to reduced sewage discharges. They also pointed to increased investment following government-imposed targets.

• £104 billion investment planned
• Average household water bills set to rise by 36% over five years

Water UK, the industry body, said: “Sewage spills are awful and we are working to end them as fast as we physically can. While the dry weather in 2025 will have led to fewer spills, we are also starting to see the effect of a tripling of water company investment. By building bigger storm tanks and expanding capacity at sewage treatment works, we will halve spills over the next five years.”

The Environment Agency stressed that while short-term improvements are welcome, sustained investment and maintenance are essential for long-term change.

The water minister, Emma Hardy, said: “It is good to see that storm overflow spills are down since the previous year, but there is still an unacceptable amount of sewage entering our waterways and a long way to go in cleaning up our rivers, lakes and seas.”

Worst-Affected Water Companies for Sewage Discharges

Some regions were hit harder than others. In 2025:

• South West Water recorded the highest discharge duration at 407,000 hours
• United Utilities followed with 327,000 hours
• Yorkshire Water discharged sewage for 285,000 hours and received a downgraded performance rating

Karen Shackleton, of Ilkley Clean River Group, said: “Today’s report creates a cover for water companies’ illegal pollution and neglect of our infrastructure. The figures for last year, in drought conditions, take us back to the level of pollution we had two to three years ago in normal weather. This is not a good news story. Yorkshire Water is still polluting illegally and the government is still failing to hold them to account.”

Meanwhile, Thames Water—burdened by £17.6 billion in debt—recorded 107,000 hours of sewage discharges and continues to face financial instability.

A South West Water spokesperson said: “The South West saw 62% more rain than the rest of England in 2025. Despite this, we still cut storm overflow spills by 17% and spill duration by 25%.

“We also prevented more than 8,300 spills, due to operational improvement, with a focus on beaches during bathing season – a clear sign our £760 million investment plan is already producing strong results. There’s more to do, but the direction is clear: fewer spills, shorter durations, and investment where it matters most.”

Despite year-on-year reductions, the continued scale of sewage pollution highlights systemic failures in England’s water infrastructure.

Campaigners argue that without urgent and sustained investment, rivers, coastlines, and public health will remain at risk.

At Natural World Fund, we believe the sewage crisis is a nature crisis. Ongoing pollution of rivers and seas harms wildlife, threatens public health, and shows the urgent need for stronger accountability and investment to protect our waterways for the future.

If you care about restoring native wildlife in the UK, support the work of Natural World Fund today.