Water Voles reintroduced to Hertfordshire river after 20-year absence
It's in an effort to reverse the decline of the species, which is currently the UK’s fastest-declining mammal
Water Voles have been reintroduced to the Upper River Lea near Wheathampstead after more than 20 years, in a project led by Herts and Middlesex Wildlife Trust in partnership with the Ayot Estate and Verulam Angling Club.
On 4 September, 100 Water Voles were released into a 1.5km stretch of river, with support from volunteers.
The release is part of wider efforts to reverse the long-term decline of the species, which is currently the UK’s fastest-declining mammal.
Populations have fallen nationally by 90% since the 1960s, mainly due to habitat loss and predation by American Mink.
The selected release site offers continuous, high-quality, Mink-free habitat with a healthy river and surrounding wetlands.
Its proximity to the Trust’s reserves at Lemsford Springs and Stanborough Reedmarsh increases the potential for future population expansion.
Harpenden Town Council also plans to reintroduce Water Voles further upstream at Batford in 2026, creating the prospect of a connected corridor along the River Lea.
Josh Kalms, Water Vole Conservation Officer at Herts and Middlesex Wildlife Trust, said:
“We’re thrilled to see Water Voles back on the Upper River Lea. These animals are vital to healthy wetlands - their burrowing and grazing helps maintain riverbanks and improve biodiversity. Water Voles eat a huge range of plants species and in doing so, they move seeds around, helping to maintain varied plant cover and creating lush and wild bankside vegetation. They are also a key food source for native species like Stoats, predatory fish, herons and birds of prey.”
“We are indebted to the Ayot Estate and Verulam Angling Club for offering this quality habitat for the release, and to our funders. I’d also like to extend a big thank you to our wonderful volunteers who provide essential support throughout, from habitat surveys and mink raft monitoring to their hands-on involvement during the release. Significant volunteer hours will be dedicated to monitoring the population after the reintroduction. As our collaborations with landowners, organisations and local authorities shows, we can get a wider spread of Water Voles through partnership work – the more people on board, the better for their future, fulfilling our goal of seeing Water Voles thriving on all of Hertfordshire’s rivers by 2030.”
The Water Voles were bred by Derek Gow Consultancy in Devon and introduced to riverside pens to acclimatise before release. Volunteers supported the process, providing supplementary food until the animals were ready to establish their own burrows.
Tom McLaughlin of Strutt and Parker, representing the landowners, said:
“We are proud to welcome back water voles to our stretch of chalk stream. Their return is a symbol of what can be achieved when landowners, conservationists and the local community work together to restore nature. This project is about more than one species—it’s about bringing vitality back to the whole ecosystem.”
Barry Killinger, Fisheries Manager at Verulam Angling Club, said:
“Angling and nature conservation are closely linked - our members recognise how important it is to protect the aquatic environment and its inhabitants. It is rewarding to know that the club, though our management and maintenance of the river’s health, we are contributing towards bringing Water Voles back into this area and overall, a more sustainable future for the river, angling and nature. Going forward we are happy to engage in any monitoring programme of the voles and also look forward to further introductions on stretches further upstream.”
The Trust will continue to monitor the population through surveys and checks for American Mink. A 2024 report from The Wildlife Trusts found a 39% national reduction in Water Vole populations since 2006, though Hertfordshire has seen local successes through conservation work.
Over two decades, Herts and Middlesex Wildlife Trust has carried out reintroductions, habitat restoration and Mink control through its Living Rivers project, in collaboration with anglers, landowners and local groups.
The county’s new Local Nature Recovery Strategy, due to launch in October, identifies Water Voles as a flagship species and indicator of river health, aligning with the Trust’s goal to see the species thriving across Hertfordshire by 2030.