Both onshore and offshore surveys have been integral to the development of Sofia since early environmental impact assessment work to inform the original development consent application. As the projects moves through its construction phase, surveys will continue to remain an integral part of our activity.
A thorough six-month offshore site investigation in 2020 collected information enabling Sofia to build up a comprehensive picture of the seafloor and sub seafloor conditions. The results also informed the need for further surveys and in 2021, the first five of 12 ornithology aerial-LiDAR surveys to collect data on kittiwake flight height and abundance were completed. The remaining surveys will be flown between March and August 2022.
Offshore pre-construction benthic surveys, taking a range of grab samples and drop down video transects along the export cable route and array area, have also been completed. As part of the benthic pre-construction surveys the team also carried out drop-down video assessments at the locations of the aids to navigation buoys to review them for sensitive benthic habitats and archaeology features. To finish our offshore survey campaigns for 2021, investigation of potential UXO and archaeology features was undertaken in the nearshore area in advance of landfall horizontal directional drilling (HDD) works beginning in spring/summer 2022 along with further UXO and archaeological surveys along the cable route.
Most of the onshore surveys are now complete in readiness for the start of building work on the onshore converter station from early 2022 and civils works on the onshore cable corridor from spring 2022. In 2021 these surveys included a team of onshore archaeologists from Durham University’s Archaeological Services (DUAS) carrying out excavation and recording work at locations along the cable route, from landfall near the coast to the Wilton onshore converter station site.