EHG6363 - DBA and walkover survey - Glen Strathfarrar

A detailed desk-based assessment and a walkover field survey were undertaken by Ramboll in 2020 and 2023 inform the appraisal of the potential effects of the proposed removal of a section of existing overhead transmission line (OHL) and supporting steel lattice towers and installation of a new section of underground cable (UGC) to replace the section of removed OHL with associated works. The study area employed for the cultural heritage appraisal comprised the 120m underground cable (UGC) easement and also included the site boundary around T13-T15 and the proposed Deanie Substation, a 60m wide corridor centred on the existing OHL, and the area inbetween. This was used to establish the archaeological baseline and to identify any potential direct impacts upon heritage assets resulting from construction of the proposed development, including access routes. Twenty non-designated heritage assets were identified by the study, centred on the proposed UGC route and along the existing OHL that would be removed by the proposed development. These records mostly related to medieval and later settlement and land use. There was one heritage asset of prehistoric date recorded in the Highland HER, and five assets recorded in the HER were of modern (20th Century) date and related to the Deanie Hydro-electric Power Station. There were no Scheduled Monuments, Listed Buildings or other designated heritage assets within the study area. Effects on designated heritage assets were scoped out of the appraisal, as was agreed during consultation with Historic Environment Scotland (HES). Following on from the desk-based assessment work, walkover field surveys were carried out over the study area as described above. An initial survey was carried out in September 2020 in good weather, and ground conditions were suitable for the identification of low relief features. An additional survey was carried out in May 2023, in similarly good conditions. Mitigation measures were set out that would ensure, where appropriate, that known heritage assets that lay within the UGC construction easement, or within working areas around existing towers, or along the route of the existing OHL that was to be decommissioned and dismantled, would be avoided as far as practicable. The possibility that unexpected, buried remains might be encountered within the construction easement for the cable installation had been appraised, based on the recorded evidence within the study area for settlement in the prehistoric period (12) and 18th Century (4a-p), as being low to moderate. This was particularly the case where the proposed UGC would pass through the former Bencharn farming township (4a-p) and a large probable stock enclosure (5), both of which occupied low-lying ground along the valley bottom, where the ground is more suitable for settlement and agricultural activities. <1>