Crystal Clear: Why Chalk Streams Matter


It might surprise you to know that flowing across East Kent are some of the most ecologically valuable waterways in the world.

Chalk streams are globally rare, occurring only in southern and eastern England, northern France, and nowhere else on the planet! We are lucky to have some of these precious habitats in the Kentish Stour Catchment.

Amap-based infographic illustrating how chalk streams are globally rare

There’s no doubt that chalk streams are special. But there’s a problem. Chalk streams are not being treated like the rare ecosystems they are. Their water levels are falling due to ever increasing demand for water, and they are damaged by pollution and centuries of human modification.


Find out how chalk streams are different to ordinary rivers and what makes them special
Chalk stream origins

Explore the chalk streams on your doorstep in the Stour catchment
Chalk streams in the Stour Catchment

Chalk streams are valuable wildlife habitats – meet the species that live in them
Chalk stream wildlife

Find out about the issues affecting chalk streams and how you can take action
Chalk streams in trouble

See how KSCP and our partner organisations are working to protect and restore chalk streams
Conserving chalk streams

Great Stour near Canterbury with water crowfoot in flower
Water crowfoot flowering in the Great Stour, Canterbury


Estimates vary. This is because some streams are small and only now being recorded and recognised as chalk streams. Also, every river is different, and the definition of a chalk stream is not precise, so there are some rivers where it is open to interpretation whether they are chalk streams. The most recent number for England, according to the organisation Catchment Based Approach, is 224. This is thought to be about 85% of all chalk streams on the planet!

The important thing to recognise is that they are extremely rare and should be a high priority for protection and conservation.

“We should value this heritage as highly as we would any other globally unique ecosystem. Chalk streams are an English Great Barrier Reef, an English rainforest. Sadly, we don’t. Instead these unique rivers are abused.”

– Charles Rangely-Wilson, author and broadcaster

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