This summer, we’re inviting visitors to join us in celebrating one of the UK’s rarest and most beautiful natural features: the chalk river that flows through Panshanger Park.
Peaceful, clear, and teeming with life, this stretch of the River Mimram is more than just a pretty sight – it’s a globally rare ecosystem. Chalk rivers are so special that there are only around 200 in the entire world, and almost all of them are found here in England.
At Panshanger, we’re proud to protect this incredible habitat with the support of our long-term custodians, Tarmac, who manage the park for the benefit of both people and wildlife.
Why chalk rivers matter
Chalk rivers are unique because they are fed by underground aquifers in chalk bedrock, which naturally filter the water. This makes the water cool, clean, and rich in oxygen – perfect for supporting sensitive wildlife species that can’t live anywhere else.
The river at Panshanger Park provides a safe haven for:
Brown trout and Grayling
Water voles – one of Britain’s most endangered mammals
Mayflies, damselflies, and other aquatic insects
Rare aquatic plants like water crowfoot
This biodiversity makes the chalk river not only vital to local ecosystems, but also a wonderful place for families and nature-lovers to connect with the environment.
A legacy of conservation
Alongside sustainable quarrying of sand and gravel, Tarmac has played a central role in restoring and managing the Panshanger landscape over many years, including the protection of the chalk river and surrounding habitats. The ongoing work ensures the area is:
Protected for sensitive wildlife species
Accessible via trails and viewing points
Cared for with long-term sustainability in mind
From meadow creation to riverbank restoration, our conservation efforts aim to keep Panshanger’s chalk river thriving for generations to come.
Summer by the Chalk River
To mark this special feature of the park, we’re running a new six-week summer campaign: “Summer by the Chalk River”, from 22nd July 2025.
Each week, we’ll be sharing:
Fascinating facts about chalk rivers
Family-friendly activity ideas
Stories about the wildlife you might see
Tips on how to enjoy the park responsibly
Whether you’re walking our riverside trails, spotting dragonflies, or simply enjoying a quiet picnic in nature, this is your invitation to make memories with the river as your backdrop.
Follow along on Instagram and Facebook (@PanshangerPark) to join in and share your own chalk river moments using the hashtag #PanshangerSummer.
Take the Chalk Stream Challenge
We’re also excited to be the first route in Hertfordshire for the Chalk Stream Challenge, a brilliant new initiative from the Herts and Middlesex Wildlife Trust.
This hands-on challenge encourages you to explore your local chalk stream, learn why it’s so rare and important, and discover the incredible wildlife and rich heritage that surrounds it.
Participants complete activities across five fun and educational themes:
Get to Know Your Chalk Stream
River Geography
River Life
River Fun
Save Water at Home or School
Whether you’re part of a Scouts or Guides group, a school, a family, or just a nature-loving individual, the activities are flexible and can be adapted to suit all ages and abilities.
After completing the challenge, you can download a certificate to celebrate your achievement – and even order a Chalk Stream Challenge badge.
The challenge was originally created by volunteers through the Watercress and Winterbournes Landscape Partnership Scheme in Hampshire, and has now been brought to Hertfordshire with funding from the Species Survival Fund and the Environment Agency. We’re proud that Panshanger Park is one of the first featured locations – with more routes to come.
To get started, download the free activity pack and route map from the Herts and Middlesex Wildlife Trust website, here.
Help us protect this special place
As much as we love to welcome visitors, it’s important to remember that the chalk river is a sensitive and protected habitat. To help preserve it, we ask all visitors to:
Please do not paddle, swim, or allow pets in the water
Stay on marked trails and paths
Take your litter home
Keep dogs under control near wildlife areas
These small actions help protect this environment for wildlife and for all those who come to enjoy it.
Come celebrate with us
Whether you’re visiting for the first time or returning for the hundredth, this summer is the perfect time to reconnect with one of Britain’s most precious natural features.
Come walk the trails, listen to the gentle flow of the river, and let yourself be inspired by the beauty of the natural world – right here at Panshanger Park.
We’d love to see your chalk river experiences. Tag us @PanshangerPark and use #PanshangerSummer to share your visit.
