The River Pang, a Berkshire chalk stream that Thames Water designated part of a so-called flagship restoration scheme, has been classified as being in "poor" ecological condition by the Environment Agency, according to figures released on Thursday. The same assessment found the waterway had also failed a separate test measuring hazardous substances.
Thames Water launched the Pang Flagship Chalk Stream Partnership in 2022, describing it at the time as a scheme intended to deliver restoration work between 2025 and 2035. The company has said it put £875,000 into the partnership, and it maintains that river water quality is shaped by numerous pressures beyond its own operations, including agriculture, industrial activity, road runoff and increasingly extreme weather patterns, which it argues demand a joined-up response from everyone with a stake in the river's health.
How has the river's condition changed over time?
According to a BBC report, Environment Agency records show the Pang's classification slid from "good" between 2014 and 2016 to "moderate" by 2019, before dropping further to "poor". The same report notes that 2022 alone recorded 17 serious water-quality pollution incidents, the highest annual total since 2013. A separate Environment Agency catchment-planning record for the Pang water body confirms the ecological status is listed as poor, with priority hazardous substances also marked as a fail, alongside chemical status changes recorded as fail or not requiring assessment between 2019 and 2022.
The BBC's earlier reporting also linked Thames Water to a wider pollution crackdown centred on its Hampstead Norreys sewage works, citing Environment Agency records showing more than 40 hours of sewage spills in August 2023 and a live investigation into the river's broader decline. Separately, NewburyToday reported that since the start of July 2024 the Pang has endured more than 430 hours of untreated sewage discharges from Thames Water facilities, with citizen-science river monitoring also detecting persistently elevated phosphate levels.
Why does this matter for chalk streams generally?
Chalk streams are considered globally rare and ecologically distinctive habitats, and of the roughly 260 that exist worldwide, 85% are found in the UK. Campaigners have previously pushed for stronger legal protection for England's chalk streams, arguing they merit specific recognition within national planning policy given their unique ecological value.
The scale of the problem extends well beyond the Pang. Research from WWF has found that only 23% of England's chalk-stream water bodies are in good ecological status, meaning 77% are failing to meet the statutory requirement. A separate strategy document from the Catchment Based Approach chalk-stream restoration group puts the total number of chalk-stream water bodies in England at 249, of which 39% have recorded phosphorus failures. This mirrors broader findings that most of England's rivers and lakes have failed recent environmental reviews, with only around one in seven waterways nationally rated in good ecological condition and none passing chemical pollution testing.
What do campaigners and officials say?
Ash Smith, who has spent a decade campaigning against pollution in Britain's waterways, was blunt about where responsibility lies.
We need a complete overhaul of the way the water industry is allowed to pollute for profit.
I don't think you can blame the weather for polluting a river, can you? In any respect whatsoever.
They are a precious resource and it's not just chalk streams, it's every other kind of river.
He argued that a well-managed river supports rich plant and fish life, but pollution undermines that balance entirely.
If you treat it with respect it is healthy, it is beautiful, it will have the plant life that is supported by that type of water and the fish life.
He added that allowing pollution to continue unchecked produces exactly the outcome now being recorded on the Pang.
An Environment Agency spokesman described chalk streams such as the Pang as a valuable natural resource that the agency is actively working to restore and protect.
Chalk streams such as the River Pang are a valuable natural resource that the Environment Agency is working hard to restore and protect.
The agency identified barriers preventing fish movement between the Thames and the Pang as the principal driver behind the decline in the number and variety of fish species in the river.
What has Thames Water said in response?
Thames Water confirmed that it selected the River Pang as a flagship chalk-stream project in 2022 as part of a wider commitment to protect and enhance what it calls a nationally important habitat.
The River Pang was selected by Thames Water as a Flagship Chalk Stream project in 2022 as part of our commitment to protect and improve this nationally important habitat.
Since 2025, we have invested £875,000 in the Pang Flagship Chalk Stream Partnership, helping to kick-start delivery of a 10-year plan to improve the health of the river.
The company said it wants the Pang catchment to become a model for how partnership working and community-led restoration can help chalk streams recover.
We are committed to making the Pang catchment a leading example of how partnership and community-led restoration can help chalk streams thrive.
It is important to recognise that river water quality is influenced by a range of factors, including farming, industry, road runoff and increasingly extreme weather.
Addressing these challenges requires a coordinated approach from all those who have a role to play in protecting and improving our rivers.
What happens next?
The Environment Agency has said a live investigation remains ongoing into the ecological decline of the River Pang, according to the BBC, suggesting further regulatory findings could emerge in the coming months. The agency has also confirmed it is working with partners through the Pang flagship project, which is expected to see £2m of investment directed toward restoring and improving the river.
Key Facts
- The River Pang's Environment Agency classification has fallen from
