Water voles thriving in Ewell’s Hogsmill
Camera footage and fresh field signs suggest water voles are settling in and spreading along the Surrey chalk stream
Water voles are showing encouraging signs of recovery along the Hogsmill River, one year after 50 of the threatened mammals were released into the river and surrounding wetlands in Ewell, Surrey.
Camera traps have captured a continuous flow of images showing the water voles displaying natural behaviours, while recent surveys have found evidence of their presence both upstream and downstream of the original release site.
The field signs include burrows in the riverbanks, feeding remains, vegetation chewed at a characteristic 45-degree angle and distinctive “tic-tac-shaped” droppings found at water vole latrines. The findings suggest the animals are exploring the river and establishing themselves within their restored habitat.
Water voles were released into Chamber Mead wetlands and the adjacent Upper Hogsmill River on 30 July 2025 by the South East Rivers Trust and conservation charity Citizen Zoo.
The release marked the return of water voles to Surrey following an absence of more than 20 years and complemented an earlier reintroduction further downstream on the Hogsmill.
Laura Nee, Catchment Officer at the South East Rivers Trust, said: “It’s wonderful to see how excited local people are to have water voles living on their doorstep. Residents often stop to tell me about hearing the tell-tale ‘plop’ of something entering the water and wondering whether a vole is nearby.
“Although water voles can be difficult to spot, our monitoring with Citizen Zoo is giving us an encouraging picture of how they are settling in. Camera traps have captured a continuous flow of images showing the voles displaying natural behaviours, while recent surveys have found signs of their presence both upstream and downstream, including latrines, feeding remains and burrows in the riverbanks.
“A year after the reintroduction, it’s incredibly exciting to see evidence that the water voles are thriving and making the Hogsmill their home.”
Citizen Zoo is monitoring the population using four latrine rafts, two camera traps and a clay tracking raft positioned along this stretch of the catchment.
The equipment, combined with regular field surveys, helps conservationists understand where the water voles are living, how they are moving along the river and whether the population is successfully establishing.
Water voles were once widespread along the Hogsmill but disappeared from Surrey following decades of habitat loss and pressure from invasive American mink.
Their return was made possible by long-term work to restore the river and create suitable habitat, including the development of Chamber Mead wetlands by the South East Rivers Trust and Epsom & Ewell Borough Council.
The wetlands provide the dense vegetation, connected river habitat and suitable banks that water voles need for food, shelter and burrowing.
The July 2025 release formed part of the WET Hogsmill project, delivered by the South East Rivers Trust in partnership with Citizen Zoo and supported through Natural England’s Species Recovery Programme.
The water voles were bred by Wildwood Trust, which specialises in conservation breeding and the recovery of native species.
The release also helped strengthen the population established further downstream, where Citizen Zoo released 101 water voles in 2022. Creating connected populations along the river can improve genetic diversity and support the species’ longer-term recovery.
Ongoing monitoring will help the South East Rivers Trust and Citizen Zoo track the population’s progress and guide future habitat conservation along the Hogsmill.
The Hogsmill is a rare chalk stream flowing through Epsom and Ewell and the Royal Borough of Kingston before joining the River Thames. Chalk streams are internationally important habitats, supported by clear, mineral-rich groundwater and characterised by distinctive plants and wildlife.
The WET Hogsmill project ran from September 2023 to 2025 and created or improved habitat for water voles, European eels and native trout. It was led by the South East Rivers Trust in partnership with Citizen Zoo and supported through Natural England’s Species Recovery Programme.
The water vole reintroduction was also supported by Wildwood Trust, Epsom & Ewell Borough Council and Thames Water.
Citizen Zoo is a social enterprise and conservation charity working to restore nature and reconnect people with the natural world through community-led rewilding and species recovery.
South East Rivers Trust
Related reports:
Water voles return to Ewell – 31 July 2025
Epsom & Ewell Biodiversity Action Plan’s five-year review ratified – 27 June 2025
Ewell’s wetlands to be celebrated on an open day – 9 April 2024
Chalking up a victory for the Hogsmill – 31 January 2024
Voles let loose on the Hogsmill – 24 January 2023
“Garden of Eden” coming to West Ewell as Wetlands Plan is approved – 23 July 2022