Chalk streams are rare and important ecosystems that face many threats. We formed the Greater Cambridge Chalk Stream Project to address these challenges.
Chalk streams rise from springs in chalk bedrock, which is known as the aquifer. The porous chalk allows water to seep through quickly, removing organic matter and sediment. The result is very clean and clear water that supports a unique array of wildlife.
Most of the world's chalk streams are in southern England, particularly in East Anglia. Hobson’s Brook and Cherry Hinton Brook are two well-known examples in Cambridge.
These rare ecosystems are important for their ecological value. The streams’ stable temperature and mineral-rich water support plant and animal communities.
Threats to chalk streams
Economic and urban growth and climate change put pressure on these delicate habitats. Chalk streams face many threats:
- Pollution and sewage from agriculture and industry can damage water quality and biodiversity. Water draining off nearby roads and buildings, known as runoff, also has a negative impact.
- Sedimentation and erosion can degrade the habitats of plants and animals that live in chalk streams. These are often caused by poor farming practices.
- More water leaving the aquifer than is naturally replenished can be a problem. This over-abstraction can be caused by farming or taking it for water supply.
- Invasive non-native species like American signal crayfish and Himalayan balsam can disrupt the streams’ ecological balance.
- Urban infrastructure development can destroy or fragment the habitats.
- Chalk streams have not been fully mapped, which complicates conservation efforts. There is also currently not much data about biodiversity or water quality in the streams.
Protecting the city’s chalk streams
We need proactive measures to protect local chalk streams. These include regenerative farming practices and riparian restoration projects. Long-term collaboration and evidence-based plans are essential to preserving these ecosystems.
We formed the Greater Cambridge Chalk Stream Project to address these challenges. Other organisations involved include local parish councils, utility companies and government agencies.
The project’s evidence-based research will help us better understand the complexities of restoring chalk streams. It will also contribute to the development of scalable solutions. Using real-time monitoring and in-depth ecological assessments will help us provide a robust foundation for making decisions.
Rather than focusing on individual streams, the project takes a catchment-wide approach. This will help to identify broader environmental pressures and inform effective long-term restoration strategies.
The project cannot fix all the issues facing chalk streams, but it will be a vital support mechanism for future restoration work.
The project’s work will help to:
- restore and preserve the region’s chalk streams
- increase biodiversity
- introduce sustainable water management practices
- support communities to enhance and sustain their local environment
Read the project report to find out more.
We fund this project with Anglian Water, the Cambridgeshire and Peterborough Combined Authority, Hobson’s Conduit Trust and South Staffordshire Water.
Get involved
We need your help to protect and keep improving the chalk streams. You could:
- join a volunteer day to help with restoration work
- take part in ‘citizen science’ projects, such as monitoring water quality or surveying wildlife
- donate to the project
- advocate for the project to help spread awareness
Look out for more information about volunteering opportunities soon, or contact us to register your interest in taking part.
Other projects
The Catchment Based Approach initiative works to improve the natural value of our environment. Their chalk stream strategy calls for giving the streams enhanced environmental status. It aims to protect, enhance, and restore them by improving water quality, managing abstractions, and restoring habitats.
