South West Water comes out “top of the flops” for driving harm to people and the environment

• New analysis assesses water companies’ performance across six key markers related to the cost of bills, sewage pollution and river health
• South West Water ranks among the top offenders across four out of the six, while Southern, Thames and Yorkshire Water trail closely behind scoring poorly across three each
• But while some companies are performing especially badly, all are failing to uphold basic environmental protections despite huge increases to bills across the country
• With the summer holidays in full flow, Friends of the Earth is calling on the government to deliver a robust Clean Water Bill when Parliament returns this autumn

Every single water company in England is failing to an excessive degree in at least one of six key areas being tracked by the environmental justice organisation Friends of the Earth, fresh analysis published today reveals.

The research, which examines which water companies are ranked among the top three worst offenders on issues that relate to sewage pollution, the affordability of water bills, bathing water quality and river health, shows that South West Water stands out above all others in an assessment of poor performance – though none are without fault.

As part of its analysis, Friends of the Earth assessed how companies fared across the following categories:

• Affordability of water bills (including those that are highest and have seen the largest proportional increase since 2024)
• Sewage spills (including total duration in hours and average duration per outflow)
• Water quality at bathing spots
• Pollution incidents or warnings at bathing spots
• Severity of sewage pollution at bathing spots – measured in spills per location
• Percentage of rivers rated below the acceptable standard for good ecological health

The findings reveal that South West Water features among the top three worst performers across four out of the six categories, relating to bills, overall sewage pollution and incidents at designated bathing spots.

On sewage spills specifically, the data shows that South West Water had the highest total duration of pollution events since 2024, averaging annually at 574,323 hours. Although Severn Trent and Yorkshire Water come in notably at second and third place, both are outstripped by South West Water by nearly, or over, 200,000 spill hours.

The company also ranked highest for average spill-time per outflow at 419 hours, with Thames and Southern Water following closely behind at 387 and 270 respectively. Meanwhile, its designated bathing spots saw the most pollution incidents and warnings recorded across all companies.

All of this comes as South West Water’s roughly 1.8 million customers face some of the highest average water bills across the country at £726 annually. Since 2024 these have seen the second biggest increase in England, rising by 39%.

The company’s poor performance is far from isolated though. Southern, Thames and Yorkshire Water all score exceptionally badly in three out of six areas, with Southern Water responsible for both the most expensive water bills in England and the biggest increase since 2024. This has seen £281 added to the average bill in that time.

Figures relating to the ecological health of rivers are also particularly stark. Thames Water fares worst with a staggering 96% of rivers within its area rated below the standard for “good” ecological health. Severn Trent Water and Anglian Water come off only minimally better in joint second place, both with 93% of rivers in a subpar condition.

The data doesn’t reveal the full extent of England’s sewage pollution crisis, however. With the country’s water infrastructure failing on a massive scale due to decades of underinvestment by privatised companies – which have favoured payouts for bosses and shareholders over carrying out the upgrades needed – the magnitude of the problem is likely far larger. 

Gill Hickman is a campaigner at New Forest Friends of the Earth, where she has played a critical role in setting up New Forest Water Watch, a volunteer group of 100 people across the area who carry out regular water testing. Concern has been so widespread among local communities that it has driven high engagement in the project.

In one incident at a nearby water course called Danestream, volunteers recorded E.Coli levels at over 100,000 CFU per 100ml. The limit considered safe for bathing is 900 CFU.

The sewage spill was eventually traced to a burst main near one of Southern Water’s pumping stations. The issue was only taken seriously by the company, and The Environment Agency, after the campaign gained traction in the local press and on social media, despite volunteers raising concerns multiple times. Gill said:

“The environmental consequences at Danestream have been devastating. The river was more or less killed. Very little was alive. We found dead fish, and we found no plants upstream. It’s going to take a really long time for the stream to recover.

“We warned people through our Facebook page to keep their dogs out because we understand that untreated sewage is more than just E.Coli – it’s other deadly bacteria and viruses too. Unfortunately, we did hear several reports that dogs got very ill indeed, which we believe is connected to the pollution at Danestream. Despite putting up signs warning locals of the danger, we’ve also had to advise people to get out of the water, including some young children holidaymaking nearby. 

“This incident is just the tip of the iceberg – we’re uncovering new spills and leaks all the time. And this is just in our small patch, we’re sure the problem extends far across our precious coastline, with so much of it connected to the appalling state of our water infrastructure.”

In the north of the country, the picture isn’t much better. On the River Calder, members of Halifax Canoe Club have repeatedly reported getting sick after being in the water. The river is notorious for being one of the worst in the country for sewage discharges.

The club has recently partnered with the Calder Rivers Trust to monitor the quality of the water in a bid to keep people safer, and to collect evidence to campaign for cleaner rivers. Steve Smith, the club’s environmental lead, said:

“People are in and out of the water a lot, so every now and then someone will get sick with an upset stomach.

“There are several sewage outflows along the river, and the pollution is often worst after heavy rainfall. You can even see it sometimes, it leaves a scum on the water. But agricultural run-off and chemical pollution from local industry are contributing to the problem too.

“Right now, it remains a very precarious place to paddle, but it shouldn’t have to be that way. If the water quality weren’t so poor, it could be a brilliant community resource – one that also supports the area’s bird and wildlife.”

This summer’s extraordinarily hot weather has seen people flocking to rivers and seas right across the country, though many remain unaware of the dangers and health risks that may await as a result of the scandalous levels of sewage pouring into our waters. At the same time, the wildlife that depends on these vital ecosystems is, in many cases, being dealt a death sentence.

With Parliament in recess, Friends of the Earth is urging the government to come back in the autumn prepared to pass a Clean Water Bill that goes far beyond the measures introduced in the 2025 Water Act.

It must put an end to this decades-long scandal by setting out a credible pathway for restoring the health of our rivers and seas so that nature can flourish and people can enjoy our blue spaces without fear.

This will require a complete overhaul of our water system – one that also addresses the injustice of water companies extracting huge profits off ordinary people through eye-watering bills, as they fail to maintain our now-crumbling water infrastructure at great cost to our environment.

That’s why Friends of the Earth believes the new Prime Minister must bring the nation’s water under full public ownership as part of building a greener, fairer future. It’s the group’s view that a resource as essential as water should not be sold for private profit, and that communities, rather than shareholders, should control the resources they depend on.

Kierra Box, water campaigner at Friends of the Earth, said:

“There’s a reason the sewage scandal has resonated so deeply with the public. Not only are we a nation of nature-lovers who can’t stand to see our beloved rivers and seas dying at the hands of corporate negligence and greed. We’re also sick and tired of paying through the nose for the privilege, with water company bosses pocketing huge bonuses as our water bills skyrocket and blue spaces slip into further decline.

“People have had enough of hearing ministers say they’ll fix the problem, only to bring in measures that superficially address the issue. If we’re to end the sewage scandal once and for all, then we must see the government committing to a complete overhaul of our water system. 

 “As well as bringing forward a robust Clean Water Bill that sets out a meaningful plan for restoring the health of the UK’s cherished and wild rivers and seas, bringing water back under public ownership is another crucial piece of the puzzle if we’re to make the system work in favour of communities instead of for profit.”

ENDS

Notes to editors:

 1. To assess water companies’ overall performance, Friends of the Earth analysed eight separate data points to reveal which companies scored in the top three worst performers across each of them. The environmental organisation then used these rankings to grade water companies across six different markers. There were two data points each for both sewage pollution and water bills – these were grouped as a single marker for each. 

Table one illustrates how water companies were graded across the six different markers – the breakdown of the data for each area follows after.

Table 1: Summary of worst performers (companies featuring in the worst three for each category are highlighted orange)

BILLS 

Table 2: Bills: highest overall cost annually (on average) – worst three

Table 3: Bills: largest proportional increase (2024/5 – 2026/7) – worst three

SEWAGE

Table 4: Sewage: Total duration of spills, annual average duration, hours (2024 – 2026) – worst three

Table 5: Sewage: Average duration of spills per outflow (2024-2026) – worst three

BATHING LOCATIONS 

Table 6: Bathing spots: water quality less than ‘good’/’poor’ or ‘sufficient’ – worst three*

*Note; Severn Trent Water and Thames Water both score very poorly on this but have less than 10 bathing locations in their catchment. They have been excluded from the top three worst performers, but included (italicised) in the table for reference.

Table 7: Bathing spots: water companies with highest number of pollution incidents or warnings at bathing locations (May – September for 2024 and 2025, and estimates for the 2026 bathing season based on May – June 2026 stats)

Explainer: Pollution warnings or incidents issued by the Environment Agency are modelled assessments of whether water quality at a designated bathing spot is likely to be temporarily reduced. The model predicts when levels of harmful bacteria are likely to be high, accounting for weather and tides (where relevant) and potential pollution from sources including agricultural land run-off, urban drainage, and road surface wash-off, as well as overloaded stormwater systems. A sewage discharge notification from a water company does not in itself generate a pollution risk forecast (PRF) - PRFs are driven by whether environmental conditions are predicted to raise bacterial levels above safe thresholds, regardless of the specific source. 

SEWAGE – NEAR BATHING LOCATIONS 

Table 8: Sewage at bathing spots – worst three**

**Severn Trent Water scores very poorly in this category but only has 4 bathing locations across its catchment area. It is excluded as a top three worst performer but included in the data table (italicised) for reference.

RIVER ECOLOGICAL CLASSIFICATION 

Table 9: Rivers below good - worst three (2025 data, published in 2026)