Creating Riparian Buffer Strips
Water voles are heavily dependent on high quality buffer strips. A buffer strip is a vegetated strip of land from 2-50m wide along a watercourse. Buffer strips provide water voles with a diverse range of food plants as well as affording cover from predators. These buffer strips also help protect riverbanks from erosion, reduce agricultural run-off and provide ideal habitat for a range of wildlife including fish. Buffer strips for water voles should not be allowed to develop into scrub as water voles dislike shade conditions, however some saplings can be allowed to grow into mature trees as the bark of willow, crab apple and hawthorn all provide winter food.
Bankside Grazing
Overgrazing by stock reduces the amount of cover and food available to water voles and poaching of the ground makes the site unsuitable by compacting the soil and damaging existing burrow systems. It is recommended that at least part of the bank is fenced to provide a refuge for the voles. Where possible the boundary line should be set back from the top of the bank to allow a species rich sward to develop. If fencing is not applicable to a site then stocking densities should be kept low; this will reduce trampling and subsequent burrow damage.
Bank Reinforcement
Bank protection is often essential, and riverbanks can be stabilised in ways sensitive to the needs of water voles. Soft engineering techniques should always be used.
Hazel wattle hurdles are ideal on
shallow slopes. The hurdles are fixed
to the eroding bank, this allows
vegetation to develop and bind the
bank together. |
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On steeper slopes spiling is an option,
poles are driven into the bank and live
willow is woven between them. Back
filling makes up the bank. |
Reinforcement work is best carried out between November and February to minimise disturbance to the water voles.
Refuge Habitats
Alternate wetlands provide refuges for water voles when watercourses suffer from a pollution incident or are liable to flooding. Ideally, such off-channel wetlands should be linked to the main watercourse by areas of dense vegetation; this provides a safe corridor by which water voles can reach the refuge site.
Riparian and Wetland Maintenance
General guidelines and generic habitat improvements when working at water vole sites are outlined below. Careful consideration needs to be taken when planning works and care needs to be taken in order to avoid breaching the Wildlife and Countryside Act. Any riparian works in areas where water voles are present could potentially be breaking the law. However, prosecution is less likely if you work to a method statement that minimises the risk to water voles and their habitat. The following should be considered:
- Survey to establish extent of population and areas of high activity,
- If possible avoid or minimise the work carried out where water voles are present,
- Retain as much vegetation as possible and work in sections, don’t do all the work in one year,
- Work from one bank and limit use of heavy machinery,
- Work upstream, as dislodged vegetation can re-establish downstream
- Take care over spoil disposal,
- No operations between March and September to protect breeding water voles. (note water vole populations are highly sensitive to disturbance even during the winter months due to their restricted home range),
- Assess potential for enhancing / restoring/ creating habitat,
- Stop work if a water vole is seen.
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