Chalk streams are a characteristic and attractive feature of the Chilterns landscape. They are also a globally rare habitat. In fact there are only 283 chalk streams in the UK, and the UK accounts for around 85% of the global total.
Chalk streams are important habitats for wildlife and support a massive range of species. They are home to some of our most threatened plants and animals, such as the water vole and brown trout. They also have a fascinating history and supported many thriving industries in the past.
Our three films provide an excellent overview, explaining ‘What are chalk streams, and why are they special‘, How chalk streams work, and exploring the threats they face.
The nine Chilterns’ chalk streams are so important that a special partnership project has been created to conserve them. Uniting all the organisations with an interest in the streams, the Chilterns Chalk Streams Project works with local people across the Chilterns to improve river habitats, improve access and enjoyment and promote the sustainable use of water.
Find out more
Chilterns Chalk Streams Project 5 Year Review
We’ve reached the end of our 2020-25 Business plan, providing a perfect opportunity to look back on what the Chilterns Chalk Streams Project has achieved over the last 5 years.

Recent News
Chilterns Chalk Streams Project set to ‘Mend the Misbourne’
The Chilterns Chalk Streams Project, which is hosted by the Chilterns National Landscape, has secured £1 million of investment from...
Citizen Scientists Needed
Citizen scientists are contributing to our knowledge of Chilterns chalk streams and monitoring the changes that are taking place. Citizen...
Hundreds of children take on the Chalk Stream Challenge
The River Chess Chalk Stream Challenge, launched in Autumn 2024, invites families and groups to explore chalk streams through a...
Events

Autumn 2025 Riverfly Training Day
- 11 October 2025
- 09:00
Riverfly monitoring is a citizen science survey that uses the...

Extended Riverfly Training - Autumn 2025
- 14 October 2025
- 10:00
This Extended Riverfly Training has been designed for existing Riverfly...

Twilight bat safari
- Saturday 27th September
- 6.30pm
An evening walk exploring the fascinating world of bats along...