What is a water vole and otter survey?

You will usually be asked for a water vole and otter survey if you’ve had a preliminary ecological appraisal that has identified a slow-moving stream, river or ditch on, or next to, your site.

A water vole and otter survey is the next step. The length of watercourse which needs to be surveyed will vary depending on your development. For example, a large-scale development requiring the permanent culverting of a watercourse will need a different, and far more extensive, survey than a small scale development that may only result in temporary disturbance to a watercourse.

Water voles and otters are rarely seen and so our ecologists concentrate on finding characteristic signs of water voles and otters, rather than the animals themselves. Field signs of water voles and otters include:

  • Latrines / dropping piles
  • Footprints
  • Paths and runs in vegetation or at the water’s edge
  • Water vole feeding stations or chopped vegetation
  • Water vole burrows
  • Otter couches / hovers (above-ground resting places)
  • Otter holts (resting places underground or in tree roots)
  • Otter slides (established entrances to a watercourse)

Our surveys are carried out in accordance with The Mammal Society’s Water Vole Mitigation Handbook (2016), which recommends undertaking two survey visits; one mid-April to June and one July to September. There are no timing restrictions for otter surveys.

What happens next?

If no field signs of water voles or otters are recorded, no further survey work is needed and you’ll be able to use this report to secure planning permission.

If field signs of water voles or otters are recorded, you’ll usually have to submit a method statement to the Local Planning Authority as part of your planning application. Our method statements detail how you will ensure water voles, otters, and their habitats, aren’t disturbed or harmed. This is often a case of simply creating an exclusion zone along the watercourse.

Are we the right surveyors for you?

At UES, our ecologists are experienced in surveying and mitigating for water voles and otters to ensure a positive outcome for your planning application.

Our surveyors are also members of the Chartered Institute of Ecology and Environmental Management (CIEEM), who promote the highest standards of practice through a professional code of conduct and continuing professional development.

For more information on the legal protection of water voles or otters, please click either of the below links: