Chalk Streams

What is a chalk stream?

Chalk streams are one of the rarest freshwater habitats on Earth, and England is home to approximately 85% of them. Found mainly in the south and east of the country, chalk streams are fed by groundwater making the good management of the chalk aquifers (stores of water in porous rock) essential to achieving good ecological health of chalk streams.

Watch a video explainer on X (Twitter) for a quick introduction to chalk streams.

What are the issues facing chalk streams?A tranquil stream flows gently through lush green foliage, reflecting sunlight on its surface under a clear blue sky.

Chalk streams have been badly damaged over many years through over abstraction of water, pollution, and poor management of their channels, floodplains, and catchments. The 2019 water framework directive classification results showed that only 17% of chalk streams meet ‘good ecological status’.

What action are we taking?An illustrated landscape with a river, trees, and buildings, highlighting collaboration among various organisations for water management.

The future of chalk streams is dependent on action by everybody: government, regulators, water companies, farmers, and landowners. We’re making progress, but there’s a lot more to do. Together with our partners, we have a plan to restore chalk streams and improve their resilience to climate change.



A tranquil, clear stream reflects lush green trees and grass, surrounded by foliage.

The strategy sets out actions and recommendations for government, regulators, and the water industry on water resources, water quality and habitat restoration and management. This is the ‘trinity of ecological health’. The case studies below show some examples of our work.

Case studiesA person taking a water sample in a clear stream, surrounded by lush greenery and yellow wildflowers under a partly cloudy sky.

Blog: Plant surveying on the River Mimram

Every June to September, Environment Agency monitoring officers conduct surveys of aquatic plant life (known as macrophytes) to determine the health of our riverine ecosystems.

Read Elodie's blog.


A muddy stream flows through a wooded area, bordered by green grass and fallen logs.

Working to Improve chalk streams

The Lincolnshire chalk streams have helped shape the Lincolnshire Wolds landscape over the past 10,000 years. Over the last 10 years, we have worked with partners on projects that create and improve these habitats.




A river flowing through lush greenery, bordered by trees and grassy banks under a partly cloudy sky.

Urban chalk stream restoration

To restore a chalk stream in the Southeast, the Ouse & Adur Rivers Trust and the Environment Agency, have been leading a project to re-route the Broadwater Brook across land at Sompting, West Sussex.




Aerial view of a rural landscape with green fields, a winding stream, scattered trees, and a road. Overcast sky.


A new wetland haven in Buckinghamshire

New life has been breathed into Buckinghamshire’s Hamble Brook in work led by the Chilterns Chalk Streams Project, the largest scheme of its kind involving the Environment Agency.



What is a chalk stream?

Chalk streams are one of the rarest freshwater habitats on Earth, and England is home to approximately 85% of them. Found mainly in the south and east of the country, chalk streams are fed by groundwater making the good management of the chalk aquifers (stores of water in porous rock) essential to achieving good ecological health of chalk streams.

Watch a video explainer on X (Twitter) for a quick introduction to chalk streams.

What are the issues facing chalk streams?A tranquil stream flows gently through lush green foliage, reflecting sunlight on its surface under a clear blue sky.

Chalk streams have been badly damaged over many years through over abstraction of water, pollution, and poor management of their channels, floodplains, and catchments. The 2019 water framework directive classification results showed that only 17% of chalk streams meet ‘good ecological status’.

What action are we taking?An illustrated landscape with a river, trees, and buildings, highlighting collaboration among various organisations for water management.

The future of chalk streams is dependent on action by everybody: government, regulators, water companies, farmers, and landowners. We’re making progress, but there’s a lot more to do. Together with our partners, we have a plan to restore chalk streams and improve their resilience to climate change.



A tranquil, clear stream reflects lush green trees and grass, surrounded by foliage.

The strategy sets out actions and recommendations for government, regulators, and the water industry on water resources, water quality and habitat restoration and management. This is the ‘trinity of ecological health’. The case studies below show some examples of our work.

Case studiesA person taking a water sample in a clear stream, surrounded by lush greenery and yellow wildflowers under a partly cloudy sky.

Blog: Plant surveying on the River Mimram

Every June to September, Environment Agency monitoring officers conduct surveys of aquatic plant life (known as macrophytes) to determine the health of our riverine ecosystems.

Read Elodie's blog.


A muddy stream flows through a wooded area, bordered by green grass and fallen logs.

Working to Improve chalk streams

The Lincolnshire chalk streams have helped shape the Lincolnshire Wolds landscape over the past 10,000 years. Over the last 10 years, we have worked with partners on projects that create and improve these habitats.




A river flowing through lush greenery, bordered by trees and grassy banks under a partly cloudy sky.

Urban chalk stream restoration

To restore a chalk stream in the Southeast, the Ouse & Adur Rivers Trust and the Environment Agency, have been leading a project to re-route the Broadwater Brook across land at Sompting, West Sussex.




Aerial view of a rural landscape with green fields, a winding stream, scattered trees, and a road. Overcast sky.


A new wetland haven in Buckinghamshire

New life has been breathed into Buckinghamshire’s Hamble Brook in work led by the Chilterns Chalk Streams Project, the largest scheme of its kind involving the Environment Agency.



Page last updated: 24 Feb 2025, 01:51 PM