A417 Missing Link

Challenge

Species, Scale & Stakeholders

The broad range of species on site, the testing terrain and habitat complexity presented significant challenges for the Keystone team.

On a project of this size and timescale, collaboration and effective communication between stakeholders was fundamental to facilitate positive outcomes. We worked closely with contractors, including those responsible for pre-planning surveys and licences, and Kier Transportation’s ecologists, as well as our own team of sub-contractors. Close coordination with site engineers, ground workers and archaeologists proved pivotal to seamless delivery.

Approach

Species Protection, Habitat Enhancement & Innovative Mitigation Design

Protected Species Management

• Translocation of over 2000 reptiles including lizards, snakes, and slow worms to suitably enhanced habitat away from construction areas.
• Installation of extensive reptile, badger and snail fencing to ensure these protected species did not attempt to return to unsafe areas occupied by the construction.
• Translocation of hazel (Corylus Avellana) coppice stands, that would have otherwise been lost, to a receptor site, where the hedgerows were defunct or fragmented.

Habitat Creation

• Creation of multiple snail hibernacula in preparation for their safe relocation.

• Enhancement of existing habitat for reptiles with the creation of multiple hibernacula and basking banks, utilising and recycling site salvaged materials including timber, brash and Cotswold stone.
• Closure of several outlier badger setts, under licence, following an extensive and comprehensive monitoring exercise.
• Design, fabrication and relocation of a single main artificial badger sett, where subsequent monitoring confirmed successful uptake.

Temporary Mitigation

• Construction of over 200m of dead hedging, the largest in Keystone’s history. This best practice measure provides commuting bats and barn owls with a linear corridor, whilst benefitting a wide range of additional species. The dead hedge will remain in situ with extensive permanent new hedges and tree lines proposed as part of the future landscaping and habitat creation.
• The innovative design and implementation of barn owl/bat screening fencing to divert commuting individuals above the existing highway and what, in due course, will become the active construction site. Fencing was designed to mimic previously existing tree lines which are to be removed to facilitate the scheme and which will be replanted upon completion.
• Fabrication and installation of two Cathedine bat roosts as a temporary measure prior to more substantial permanent bat houses that will be created on the scheme by enhancing historical features on the site.

Outcome

Community, Connectivity & Nature

The A417 Missing Link scheme seeks to benefit local communities, achieving free-flowing functioning traffic and safe infrastructure whilst retaining the wildlife and overall aesthetic of the National Landscapes. Keystone’s contribution focussed on the vital protection, preservation, and enhancement of the wildlife within the surroundings by:

• Ensuring the maintenance of protected species populations in the local area including roman snails, bats, badgers, and a variety of reptiles species including adders, slow worms, and common lizards.
• Undertaking extensive mitigation required on site, we laid the foundation for future enhancement works and wildlife connectivity to include soft landscaping, extensive woodland and meadow creation and installation of environmental bridges which will act as wildlife corridors whilst also allowing pedestrian passage over the new highway.
• Providing significant employment opportunities with more than a dozen subcontracted staff being employed at varying levels to support a similar number of our in-house team. Following a successful short-term contract, full-time employment has been provided to several individuals.
• Ongoing monitoring of the site will reveal success of mitigation, which can then be used to inform any further mitigation and enhancement works, should they be required, to ensure favourable conservation status.
• As the project enters its next phase, subsequent works will include the wider landscaping to incorporate large scale woodland, grassland and habitat creation that will ensure connectivity for nature.