Services · Specialist

Water Vole Surveys

The water vole is Britain's most rapidly declining native mammal and has received full legal protection since 2008. If your development affects ditches, streams, rivers, ponds or wet grassland, water vole survey is likely to be required.

Survey seasonApril – October
Visits required2 (spring + late summer)
ProtectionFull (Schedule 5 WCA)
MethodField signs survey

Overview

The water vole (Arvicola amphibius) has undergone one of the most severe declines of any British mammal — an estimated 90% population loss since the 1970s, driven primarily by habitat loss and predation by American mink. In response, water voles have been fully protected under the Wildlife and Countryside Act 1981 since 2008, making it an offence to kill, injure, take, possess or disturb water voles, or to damage, destroy or obstruct access to their burrows.

Water vole surveys are based on searching for field signs along watercourses, ditches and wetland margins: latrines (piles of droppings), burrows in the bank, feeding stations (neat piles of cut vegetation), grazed lawns at burrow entrances and runways through bankside vegetation. Two survey visits are standard — one in spring (mid-April to June) and one in late summer (July to September) — to capture both the early-season establishment period and the peak population.

Where water voles are confirmed and the development will affect their habitat, mitigation options include habitat enhancement, displacement (under licence, by progressively reducing vegetation to encourage voles to move to adjacent retained habitat) or — in more significant cases — capture and translocation under a Conservation Licence from Natural England.

When you need this

  • Your development is near rivers, streams, ditches, canals, ponds or wet grassland
  • Bank reinforcement, culverting, piping or channel modification is proposed
  • Your PEA identifies suitable water vole habitat within or adjacent to the site
  • Biological records show water voles in the area or the watercourse is within known water vole range
  • The LPA or Environment Agency requests water vole survey

Our approach

  1. 01
    Habitat assessment

    A walkover to assess the suitability of watercourses and wetland habitats for water voles — bank profile, vegetation structure, water depth, connectivity and the availability of foraging habitat.

  2. 02
    Field signs survey (visit 1: spring)

    Systematic bank-side search between mid-April and June for latrines, burrows, feeding stations, grazed lawns and runways. Survey covers both banks to a distance of at least 2 m from the water's edge.

  3. 03
    Field signs survey (visit 2: late summer)

    A repeat survey between July and September captures the peak population and confirms the presence and extent of water vole activity. Latrine counts provide a relative density estimate.

  4. 04
    Mitigation and licensing

    Where water voles are present and the development will affect their habitat, we design a proportionate mitigation strategy — habitat enhancement, displacement or translocation — and prepare any necessary licence applications.

Frequently asked questions

01How can I tell if water voles are present?+
The most diagnostic field signs are latrines — small piles of droppings deposited at regular points along the bank. Burrows with neat, rounded entrances at or just above water level, grazed lawns of short vegetation at burrow entrances and neat piles of cut stems at feeding stations are also characteristic.
02What is the difference between water vole and rat burrows?+
Water vole burrows tend to have neat, rounded entrances (often with a grazed lawn around them) at or just above water level. Rat burrows are more irregularly shaped, often with excavated soil visible, and lack the grazed lawns and neatly placed feeding piles characteristic of water voles.
03Can development proceed if water voles are present?+
Yes, with appropriate mitigation. Options range from habitat enhancement and phased vegetation management (to encourage natural displacement) through to capture and translocation under a Natural England Conservation Licence for larger-scale impacts.
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