Chalk Streams: ‘Our equivalent of the Great Barrier Reef’

Chalk stream's crystal-clear streams flow steadily through carpets of watercress and water crows-foot, with gravelly beds offering breeding sites for the critically endangered chalk stream salmon, as well as trout and lamprey. This rare habitat only forms in chalk landscapes where water bubbles up from chalk aquifers, resulting in mineral-rich, pure water which stays at the same temperature year-round.

The author of this blog, Emma Pritchard volunteering at the river Ver.

Guardians of the River Ver

There are only 260 known chalk stream rivers around the world and 85% of these are in southern and eastern England. My local chalk stream is the River Ver. I volunteer with the Ver Valley Society which aims to protect this precious habitat. Each month, we undertake a variety of practical tasks such as building berms to slow down water flow and increase habitat diversity for wildlife, deadwood hedges to protect trout redds, and even planting trees, putting up nest boxes and building hibernaculums for reptiles. In recent years, the society supported the Wildlife Trusts in reintroducing endangered water voles to the river; a population is now thriving there. Working in and around the river has boosted my appreciation for its potential to support a myriad of species.

However, despite chalk streams being an even rarer habitat than rainforests, in 2024, thousands of hours of sewage were dumped into the River Ver. Water testing found high levels of nitrates and phosphates and in places below the local sewage works, the river is almost ecologically dead. 

Emma Pritchard volunteering at the river Ver.

Threats to Chalk Streams

The Ver is far from exceptional in this regard. Many chalk streams across England are subject to sewage and agricultural run-off, as well as overabstraction (taking out more water from the river than can be replenished) and man-made modifications. These ecosystems have long suffered from human intervention and neglect. A 2014 report from the WWF found that over three-quarters of chalk streams were not in good health. 

UNESCO World Heritage Status

Although local volunteering does make a difference, wider action is needed and it’s clear we need to act now to protect the amazing places we have on our own doorstep. Recently, a new bill was introduced in parliament by Liberal Democrat MP Pippa Heylings, in hopes of protecting chalk streams. If successful, this bill would require the Government to apply for UNESCO World Heritage status for these extraordinary ecosystems. As Heylings highlights, chalk streams are ‘our equivalent of the Great Barrier Reef’. 

A UNESCO World Heritage designation would oblige the UK to protect and conserve these habitats. It would also bring more international recognition, funding and research. However, it wouldn’t automatically give chalk streams legal protection under UK law. 

Liberal Democrat, Pippa Heylings MP

Statutory Protections

Sarah Green, the MP for Chesham and Amersham is also sponsoring a bill – the Chalk Streams (Protection) Bill – which is intended to create a new statutory protection category in UK law for chalk streams. If this bill were passed, it would make public authorities legally responsible for protecting chalk streams against ‘pollution, abstraction and other forms of environmental damage’. 

Liberal Democrat, Sarah Green MP 

The Long View

It is promising that several MPs are putting energy towards the conservation and restoration of these globally unique waterways (alongside and with the help of many local and national organisations). These irreplaceable habitats need as much support as they can get as they face major threats such as climate instability and urban development.

---

UKY4N's Not So Freshwater Campaign

Ahead of the May elections, UK Youth for Nature is campaigning to make freshwater conservation an election issue in Wales. Through a series of roundtable meetings with MSs, we’re bringing young people’s demands for nature directly to the Senedd.

If you live in Wales, please email your MS with a copy of our manifesto for Welsh freshwater. A draft email and downloadable PDF can be found here.

If you're a young person who lives in Wales, please join our campaign by emailing ukyouthfornature@gmail.com with a little bit about yourself and how you’d like to get involved. Our co director Ellen will then reach out to organise an onboarding call.