Protecting chalk streams in Cambridge
Open for comments from Friday 3 to Friday 17 October 2025.
Cherry Hinton Brook and Coldham’s Common are two of Cambridge’s hidden chalk stream treasures, rare habitats at the heart of the city.
Together they support specialist wildlife and provide a peaceful escape for people. But these streams are fragile: banks are eroding, gravels are smothered with silt, and pollution pressures are increasing.
We want to protect and restore these special places. By stabilising banks, cleansing gravels, enhancing flows, and creating habitats, we can give sensitive chalk stream species a future while keeping paths safe for people. These works are only a first step. Each site is a case study demonstration project, designed to test practical solutions and gather robust evidence on how urban chalk streams can be made more resilient.
Both sites form part of the Greater Cambridge Chalk Stream Project’s network of case studies. Each will be monitored before, during, and after restoration to study water quality, biological communities, and sediment processes. This evidence will guide future restoration across the city and beyond. Local people and volunteers will play an active role, through citizen science monitoring and hands-on restoration activities.
Have your say
Tell us your priorities for these stretches: where you see erosion, silt, or habitat change, and how you use the brook and the Common. Your input will help refine designs and guide monitoring.
Select the 'Take the survey' button to have your say.
A hard copy version of this survey can be downloaded here:
If you are completing a hard copy survey, please return it to our Customer Service Centre in person or via post at the following address:
Communications and Engagement Team, Customer Service Centre, Mandela House, 4 Regent Street, Cambridge, CB2 1BY
The survey closes on Friday 17 October 2025. Any responses received after this date will not be considered.
If you are in need of any further assistance, please email us at communications@cambridge.gov.uk.
Next steps
We will review all comments, publish a summary of what we heard, refine designs, and share monitoring results openly.
Phases
Publish report
- Plans to be finalised and works scheduled promptly, prioritising bank stabilisation and habitat creation where impacts are greatest.
End of survey report
How often do you use the Burnside to Sainsbury's path?
What issues have you noticed along Cherry Hinton Brook?
Litter and pollution are frequently mentioned concerns, with several respondents noting visible rubbish, fly-tipping, syringes, and suspected water quality issues. Silt build-up and lack of aquatic plants are also recurring issues, often linked to excessive shading from overhanging vegetation and past bank works. Bank erosion and collapsing paths, particularly near Sainsbury’s, are highlighted as safety concerns, with narrowing paths and unstable fences noted. Low water levels and lack of wildlife are mentioned as signs of ecological stress. Overgrown paths and excessive vegetation are seen as barriers to access and light. Several respondents either do not use the area, have not visited recently, or did not notice any issues. There is a strong sense among some that chalk streams need protection, even if they are not personally familiar with this particular brook.
Drop a pin on the map where you see erosion, silt or pollution.
In your view, which outcomes should be prioritised?
Do you have any other comments to make about Cherry Hinton Brook?
How often do you visit the Coldham's Common/Abbey Pool area?
What benefits do you see from creating a demonstration chalk stream site here?
Draw an area on the map where you think habitat creation would be most beneficial.
Do you support the creation of pollution interception systems upstream of Coldham's Common to improve water quality for wildlife and people?
Do you have any other comments to make about Coldham's Common?
How important do you think it is to monitor water quality and publish the results openly?
1 - Not important
5 - Very important
How important do you think it is that the project tackles not only habitat restoration but also the causes of pollution?
1 - Not important
5 - Very important
Do you have any further comments to make regarding chalk stream restoration in Cambridge?
Demographic data
Respondents are invited to share some details about themselves as part of the registration process on our online engagement platform. This helps us better understand how representative the responses are of the people who live and work in Cambridge.
To ensure that the survey is accessible to as many people as possible, we do not make it compulsory to provide this data. The online engagement platform is continually working to improve how it presents this data.