Image description: Two large pipes extend into choppy ocean water. Image by Jennifer Simmons / Unsplash
Water companies released raw sewage into England’s rivers and seas almost 300,000 times last year, equivalent to a 35% reduction in spill numbers compared with 2024, according to the latest Environment Agency (EA) figures.
Alongside a substantial fall in average spills per overflow, the EA also noted total monitored spill duration in 2025 fell by 48% compared with the previous year. In 2025, there were 1.9 million hours of sewage spilled, compared to 3.6 million hours the year before.
Speaking on behalf of the regulator, EA Chair Alan Lovell said these “substantial reductions in spill duration and events are a clear win for people and the environment.”
Disentangling the reasons behind reductions
The regulator said most of this improvement can be put down to drier weather, with 2025 recording the driest spring for more than 100 years and the sunniest and warmest year on record in England.
Raw sewage is often spilt via storm overflows during episodes of heavy rain, a design aimed at preventing the system becoming overwhelmed and backing up into people’s homes. So with less rain there are likely to be fewer sewage releases.
Dry spills accounted for one in 20 of all spills last year
While the vast majority of sewage spills are legally permitted during heavy rainfall, for the first time this year the Environment Agency (EA) published data on the number of dry spills – after instructing water companies to collect this information. Dry spills are when sewage is spilled without any rain in the previous 24 hours and are likely to be illegal.
The Environment Agency reported that there were 14,700 such spills, around one-in-twenty of all spills last year.
Sewage poses significant risks to the environment, wildlife and people – risks which are even more pronounced during dry spills with no rainwater to dilute the sewage.
In 2024, leading scientists including Prof Chris Whitty, chief medical officer for England, published a report warning that sewage entering our waterways represented a danger to public health.
James Wallace, chief executive of the charity River Action said “water companies cannot hide behind rain clouds… we must not be fooled that everything is better just because the weather was dry. Nothing has changed: corporations are fouling our rivers for profit and the regulators let it happen.”
Water UK says investment in water sector is working
The industry body Water UK has acknowledged that fewer spills last year was down in part to drier weather, but it says a tripling of investment is having an impact.
Water UK pointed to the efforts of one company, United Utilities, who upgraded more than 400 storm overflows in its patch and Yorkshire Water, which had upgraded around 100 in the last few years. There are nearly 15,000 overflows across the country.
A key development in recent years has been the rollout of event duration monitors (EDMs) across all storm overflows in England, providing, for the first time, a comprehensive national picture of spill activity. The increased availability of data has enabled regulators to better assess water company performance and target interventions where they are most needed.
The Environment Agency stressed there would need to be “sustained investment to bring lasting improvements”, but is also optimistic improved transparency is already driving investment and action across the sector. EDM analysis has reportedly supported £10.2 billion of investment in storm overflow upgrades, forming part of a wider £104 billion planned for water infrastructure over the next five years.
Government says it is taking action
The Environment Agency has said it was now investigating the dry spills that were reported. In some cases the monitors that measure sewage spills can misfire but if the regulator does find these incidents occurred it will take enforcement action, it said. That could be a warning, an unlimited fine or criminal prosecutions for the most serious offences, supported by strengthened enforcement powers which will be introduced through the Environment Act 2021 and the Water (Special Measures) Act.
Water Minister Emma Hardy said she welcomed the news that storm overflow spills were down last 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”.
She added: “That’s why this government is taking action. We’ve banned unfair bonuses, ringfenced a record level of investment and introduced landmark legislation to hold water companies to account – including prison time for water company executives who obstruct investigations.”