Case study: Burbo Bank Windfarm Extension

Supporting large-scale construction project and protecting biodiversity

We were approached by RPS to assist them in carrying out ecological surveys and assessments for the onshore cable route for the Burbo Bank Windfarm extension.   

This was a long-term project with the ecological surveys being carried out over a number of years, later including translocation and other pre-construction works following planning permission.  The windfarm is equipped with 32 wind turbines, and at time of construction these were the largest in the world.   

The process   
Enfys Ecology carried out the following species surveys working with local sub-contractors.  

• Bats – ground-based tree assessments, tree emergence surveys, transect and static survey
• Great crested newts
• Otters
• Water voles
• Dormice
• Badgers
• Natterjack toads
• Barn owls
• Wintering birds

The site was the 12km cable corridor; to carry out all these surveys required much organisation and enormous survey effort. All surveys were carried out following best practice guidelines.  

Following the initial surveys, pre-commencement work was carried out, including the translocation of great crested newts from six areas within the corridor. Trapping on different sections varied from 30 days to 90 days, with numerous sections trapped consecutively. This involved a high level of organisation to enable all the work to be carried out to the daily schedule, as set out in the method statement and Natural Resources Wales (NRW) licence. Update surveys were also carried out.  

Following the completion of pre-construction surveys, we were employed directly by Dong energy (now Ørsted) to act as Ecological Clerk of Works (ECoW) during the construction phase of the project.  This involved attending construction meetings; highlighting any possible constraints to avoid (where possible) delays to the programme; carrying out walkover checks of the cable route; and monitoring exclusion areas for water voles, and newt-fenced areas.  

The outcome 
We designed the great crested newt mitigation ponds and supervised their construction; there are now five ponds in total: two Sustainable Drainage Systems (SUDS) ponds and three mitigation ponds. We also undertook habitat creation in the mitigation area - including tree, scrub, hedgerow planting and seeding. This area is now an undisturbed area for wildlife that joins up with mitigation areas from other windfarm projects, creating a wildlife haven.  It also links up with St Asaph Business Park, a known great crested newt hotspot that has been designed with great crested newts and connectivity in mind. We continue to be involved (through a multinational consultancy) with the ongoing species monitoring and habitat management.  This project was audited externally throughout.