Willington Wetlands - Bringing Beavers Back

Derbyshire Wildlife Trust

Product

Torus RL19/180/5 C14

Torus RL23/240/5 C5

Torus RL6/50/5 C5

As ecosystem engineers, beavers provide an enormous positive influence on the landscapes and environments that they occupy. The Eurasian beaver is a native species to Britain and their populations used to span across the entire UK. However, the over hunting of the species in the 16th century led to their extinction.

Beavers are notorious for gnawing on stems of trees like willow and hazel, the species naturally coppice their environment providing the regrowth of habitats for various insects and birds. Thus, beavers are imperative to improving biodiversity and improving the health and functions of river catchments by damming water courses and creating canal systems, they are able to improve the consistency of waterflow of the waterbody.

Challenge

Willington Wetland has been owned by Derbyshire Wildlife Trust since 2005, prior to the trust acquiring the site, Willington was utilised as a sand and gravel quarry. The materials were extracted for decades leaving a series of deep pits across the 114 acres. With an aim to recover the industrial scars of the landscape Derbyshire Wildlife Trust have gently helped nature and wildlife reclaim by reducing human impact whilst introducing waterflow between the pits (Egginton Brook), enriching the wetland and providing the perfect habitat for beavers.

Derbyshire Wildlife Trust proposed the erection of a beaver proof fence around the whole of the Willington Wetlands Nature reserve, this will enable beaver access to 46 hectares of wetland habitats. The trust were able to secure funding for the project through BIFFA, Severn Trent, the National Lottery Heritage funded ‘Transforming the Trent Valley’ scheme and by public donations.

Approach

Derbyshire Wildlife Trust produced a specification which requires 5no. types of fencing, each fence variation is a result of changing ground and environmental conditions across the site. Prior to installing the fence Sanctus have studied the service plans of the area and have scanned the area for underlying services using a CAT and Genny.

Standard Fencing

The ‘Standard Fencing’ Specification is allocated to the areas of site which remains dry for majority of the year. The fence comprises posts 1800mm in height and driven 600mm in to the ground. The wire mesh is attached to the inside of these posts from ground level to the top of the post (1200mm). At the base of the standard fence an additional ‘anti dig’ skirt has been attached which are pegged in to the ground using metal stakes.

The ‘Standard Overhanging Fence’ is installed along the areas upstream and downstream end of Egginton Brook, this section is installed where prime beaver activity will be carried out where they may attempt to climb out of the enclosure. This fence is built similar to the ‘Standard Fence’ described above. The difference is an additional section of mesh is added to the top of the fence, this creates an overhang in to the enclosure which discourages the beavers from climbing out of the enclosure. This has been created using a galvanised metal bracket with an angle of 45° from the top of each post with an additional mesh panel 0.5m long attached to the bracket.

Standard High Fencing

‘Standard High Fencing’ has a similar design to the ‘Standard Fencing’. However, this design requires a 2400mm post which is driven 600mm below the ground. A wire mesh is installed from the top to the bottom of the post (1800mm), with an anti-dig skirt added to the base.

High Overhanging Fencing

The ‘High Overhanging Fencing’ incorporates the design of both ‘Standard Over Hanging Fencing’ and the ‘Standard High Fencing’. The design requires a 2400mm post driven 600mm in to the ground. With mesh panels connecting each post from top to bottom and an anti-dig skirt. In addition to this section of mesh is added to the top of the fence, this creates an overhang into the enclosure which discourages the beavers from climbing out of the enclosure. This has been created using a galvanised metal bracket with an angle of 45° from the top of each post with an additional mesh panel 0.5m long attached to the bracket.

Trench Fencing

The design for the ‘Trench Fencing’ is slightly different from all of the above, this design will be constructed in the soft, wet and ‘peaty’ ground condition areas of site. The alteration in design prevents the beavers from burrowing under the surface and escaping the enclosure. In this location Sanctus has excavated a trench along the fence line to a depth of 1000mm below ground level, Sanctus has opted for metal posts in the design to eliminate the risk of wooden post rotting. The posts measure 2400mm, and once the mesh has been suitably installed the structure will be driven to 1000mm. Once installed the trench has been backfilled with the arisings and ‘Standard Fencing’ design has been constructed above ground.

Culvert Installation

To ensure that the beavers remain within the enclosure Sanctus have installed a culvert both upstream and downstream to prevent the beavers migrating out of the enclosure. The culvert itself is formed of precast sections that were built off site. Across the top of each culvert grille Sanctus has constructed a ‘Standard Fence’ with an anti-dig skirt extending down the bank of the culvert which have been tied in to the structure to prevent the beavers from burrowing around the structure.