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The construction and placement of overhead powerlines impact the surrounding environment in many ways. With powerlines taking up airspace avifaunal species are impacted in unique ways. The following article will seek to explain how overhead powerlines impact avifaunal species, how an avifaunal impact study is conducted, what are the guidelines of the avifaunal impact study, how does an avifaunal impact study fit into environmental authorizations, and how ENVASS can assist you in environmental assessments required for overhead powerlines.

The construction of overhead powerlines impact on avifaunal species on the ground and in the air. Pylons are required to hold the overhead powerlines in place which impact avifaunal species on the ground by destroying their terrestrial, riverine, freshwater, and/or wetland habitat where the pylons will be constructed. These different habitats that can be potentially destroyed in the construction and erection of the pylons are used by avifaunal species for roosting, nesting, and foraging for food (Van Rooyen & Froneman, 2020) (Smallie, 2009). The construction of these pylons impacts the habitat through habitat destruction and direct disturbance (Van Rooyen & Froneman, 2020) (Smallie, 2009). The powerlines themselves impact avifaunal species by obstructing previously clear airspace (Van Rooyen & Froneman, 2020) (Smallie, 2009). Avifaunal species migrate between different habitats, to and from feeding places, and to escape predators. If there are no suitable mitigation measures in place such as bird flight diverters, birds often collide with these powerlines resulting in a loss of life and loss of biodiversity (Van Rooyen & Froneman, 2020) (Smallie, 2009).

Before construction of overhead powerlines and pylons can commence, an avifaunal impact study is required. An avifaunal impact study comprises of: A desktop study; A reconnaissance survey, which is when you go to the project site for 2 to 4 days to inspect the site and use information based on the desktop study; Pre-application monitoring plan, this plan consists of an overview of the study area, what avifaunal species occur in the area; and lastly an avifaunal impact assessment which is a report of the findings, impacts and mitigation measures in line with relevant legalisation from observations found while on site and during the desktop study (DFFE, 2020).

The avifaunal impact study report comprises of standard headings in a scientific report but also includes a sensitivity assessment, assessment of proposed impacts of the pylons and powerlines on the study site, provision of mitigation measures, and recommended protocols and necessity of future monitoring (Botha, 2018 and Mora, 2021)

An avifaunal impact study fits into environmental authorisations according to Appendix 6 of the Environmental Impact Assessment regulations which states that a specialist report needs to be prepared in term of the regulations, and there are numerous regulations that are stipulated within the appendix (DFFE, 2014). Please find the government gazette with what is needed for specialist reports in the link below: https://www.dffe.gov.za/sites/default/files/legislations/nema_eia2014regulations_g38282_0.pdf