Water demand and weather blamed for dried-up Cambridge brook

Local residents say they have never seen the chalk stream in Coldham's Common dried-up before

A chalk stream which has dried up has led to accusations of over-abstraction by a water company.

Residents near Coldham's Brook in Cambridge said they had never seen it dried-up before, including Monica Hone who tweeted images of it.

The Environment Agency said it was not aware of any illegal abstraction there.

Cambridge Water admitted "flows in the brook had reduced... due to an exceptionally dry period".

The company said it had an obligation to provide water to customers and urged the public to use water wisely.

Chalk streams are rare habitats often referred to as England's equivalent of rainforests.

Licences issued by the Environment Agency (EA) allow water companies and farmers to take water from rivers, lakes and groundwater aquifers.

Most drinking water in the East of England comes from rainwater stored in deep, natural chalk aquifers, which feed chalk streams.

In a statement, Cambridge Water said: "The amount of water we abstract from the environment depends on many factors, including customer demand.

"As we have a duty to supply customers and meet demand, we continue to urge customers to use water wisely."

An EA spokesperson said: "Sadly, we have received reports that Coldham's Brook has run dry due to a combination of the current drought and existing water abstraction pressures."

A picture of Coldham's Brook 11 years ago showed higher water levels

Resident Ms Hone said when streams were affected by low water levels, it could lead to "huge biodiversity loss".

Cambridge Water has funded a city council project to improve the habitat of Coldham's Brook.

It said: "The habitat improvement measures will make the brook more resilient to extreme weather in the future.

"Funding projects to enhance and protect chalk streams, alongside reducing abstraction, is a fundamental part of our future strategy for managing our water resources."

'Need a wet winter'

The majority of Coldham's Brook flows through Coldham's Common, a nature reserve run by the city council.

Rosy Moore, executive councillor for environment, climate change and biodiversity, said they had been working with the Wildlife Trust and other organisations to "improve the health and biodiversity value" of the upper reaches of the Cherry Hinton Brook chalk stream and the downstream Coldham's section.

During the summer, she said gravel was added to the stream and then shaped to create riffles, pools, drops in levels and curves in the water course, which would help to increase the flow speeds and allow the stream to shift built up silt deposits.

"We're sadly seeing the real-world impacts of drought on this habitat. We need a wet winter.

"But, even after substantial rainfall, it can take time for the aquifer that feeds the brook and other local chalk streams to recover," she added.