South East Water worst for supply - how do the rest fare?

South East Water is the worst in the industry for supply interruptions, a new report says, while Southern Water and Thames Water perform badly on environment.

A new report from joint water regulators Ofwat, the Drinking Water Inspectorate, the Environment Agency, and National Resources Wales, has been released to give a single view on performance.

The report found Southern Water and Thames Water saw a combined 765 pollution incidents in 2025, while South East Water saw its average minutes of supply lost per property it serves increase sixfold compared to 2024.

Spokespeople for the water companies say they had made progress on performance.

In the report, all of the area's water companies were found to have drinking water of an "exceptional standard".

For Southern Water, which provides water to parts of Sussex and Kent, and covers sewerage services for most of the South East, the company had its "strongest-ever performance for minimising water supply interruptions", according to the report.

But the water company also has a high number of pollution incidents and "has failed to complete all necessary environmental improvement actions on time", it added.

Southern Water customers also have the lowest satisfaction levels of the water industry, with the regulators saying it "must substantially improve customer interactions".

Customers have not been under hosepipe restrictions this summer, while South East Water customers have been.

Southern Water was, however, fined more than £7 million in July for dumping sewage off the Kent coast between 2019 and 2021.

Tim McMahon, the company's chief operating officer, said: "Ofwat's report says Southern Water's performance is 'improving', recognising the progress we're making in key areas, though we're not yet out of the lower category.

"Meaningful change won't happen overnight, but we've made significant progress since launching our turnaround plan, and we're determined to continue that improvement."

In South East Water's area, covering parts of Sussex and Kent, the joint regulators report found that environmental performance was showing "areas of improvement", with the company recording 57 pollution incidents, none of which were classed as serious.

However, following several supply interruption incidents in 2025, the water company's performance was found to have "deteriorated significantly".

The company also ranked low for customer satisfaction, adding that it should improve customer interactions.

Regulator Ofwat placed South East Water under an independent monitor earlier this month, and the company was ordered to spend £30.5 million on improvements in July after several investigations into its performance.

South East Water customers have also been under hosepipe restrictions after the South East experienced its driest April to September period in over a century this summer.

Customers in Tunbridge Wells and parts of Kent were also hit by multiple water outages in 2025 and 2026, which left up to 70,000 people without water.

John Halsall, the water company's new chief executive, said it "openly accepts that our past performance did not consistently meet the high standards our customers rightly expect".

He added: "Rebuilding trust requires decisive action, and we are already seeing clear, positive progress across our operations as a result of major strategic updates.

"We are doing all we can to prove that we mean what we say and that we are determined to rebuild trust in the communities we serve."

Thames Water, which covers parts of Surrey and London, had 464 pollution incidents, including 24 classed as serious, in 2025, according to the joint regulator report.

Ofwat has also placed the company under further oversight "following concerns with financial resilience, operational performance and ability to deliver for customers and the enviornment", the report added.

"The company must reduce leakage and household consumption to secure water supplies", it said.

Thames Water customers also remain under a hosepipe ban.

A spokesperson for the company said it has "made strides in our performance" and that it is "pleased Ofwat recognised our progress by designating Thames Water as improving".

It added: "This is a company improving its operational delivery, however, it will take time for the benefits of investment to be reflected in regulatory performance."

SES Water, which serves parts of Surrey, recorded no serious pollution incidents in 2025, and only 10 pollution incidents across the year.

The company, which serves around 700,000 people, perfoms better than most of the industry in terms of water leakage per property, the report added.

The regulators also found it needs to "take action" to ensure there is enough water to meet future need.

"Customers report levels of satisfaction broadly in line with others in the industry, but it should do more to improve customer interactions and overall experience", the report added.

Affinity Water, which covers a small section of the Kent coast, was found to have a "largely positive" environmental performance, and is taking actions to improve the environment both in the short and long term, the report found.

Reported leakages per property were also better than the industry average, but customers still reported relatively low levels of satisfaction compared with other companies in the industry, it added.

Affinity recorded 39 pollution incidents, but none of these were classed as serious, the report found.

Across the water industry, the environmental performance of companies fell last year despite investment in the industry, according to the joint report.

Eight of the nine companies in England were rated as "poor" or "requiring improvement", while the chair of the environmental regulator said the results showed the industry continued to "fall well short of the standards rightly demanded by both us and the public".

Serious pollution incidents in 2025 were a "major concern", the Environment Agency said, and remained at similarly high levels to those seen in previous years.

Overall, England's water companies were awarded 16 out of a possible 36 stars for environmental performance - the worst total on record.

Follow BBC Kent on Facebook, on X, on Instagram and listen to BBC Radio Kent on Sounds. Send your story ideas to southeasttoday@bbc.co.uk or WhatsApp us on 08081 002250.