The water quality of a Berkshire chalk stream - named by Thames Water as part of a "flagship chalk stream restoration project" - has been classed as "poor" by the Environment Agency.

In the figures released on Thursday, the River Pang also failed a test for hazardous substances.

In 2022, Thames Water began the Pang Flagship Chalk Stream Partnership, which it said would "deliver restoration plans from 2025 to 2035".

Thames Water said it had invested £875,000 in the partnership, adding river water quality was influenced by a range of factors, "including farming, industry, road runoff and increasingly extreme weather" and "addressing these challenges" required "a coordinated approach".

Chalk streams are rare, diverse habitats and, of the 260 chalk rivers in world, 85% of them are located in the UK.

Ash Smith, who has spent a decade campaigning against the pollution of Britain's waterways said: "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 added: "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."

But he said if waterways become polluted, "you're going to get the situation you're in now".

An Environment Agency (EA) spokesman said: "Chalk streams such as the River Pang are a valuable natural resource that the Environment Agency is working hard to restore and protect."

It added the "key driver" for a reduction in numbers and types of fish in the river was "barriers to fish movement" from the Thames to the Pang.

In a statement, Thames Water said: "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 firm added: "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."

The EA added it was working with partners, including through the Pang flagship project, which would see £2m of investment "to help restore and improve the river".