Despite perceptions of pristine condition, upland environments are increasingly subject to a range of anthropogenic pressures including air pollution, climate change, land-use change and evolving land management strategies. Although they have received little attention to date, the large-scale development of upland wind farms also has the potential to disturb vegetation and soils, alter hydrology and water quality and, thus, impact freshwater ecosystems. This paper presents the findings of a 5-year study of the impacts of wind farm construction on the freshwater environment. Data on water quality, invertebrate and fish populations were collected for 2 years before construction and for the following 3 years covering the construction period and the initial period of the farm’s operation. In contrast to previous studies, the impacts of the wind farm development were assessed for a suite of potentially affected hydrochemical variables using a before-after-control-impact (BACI) analysis that allowed separation of construction effects from spatial and temporal variability in hydroclimatological conditions, thereby providing an improved, more robust evidence base. There was a small but significant negative effect of construction on pH, alkalinity (Alk) and acid neutralising capacity (ANC) in the upper part of the treatment catchment, which was where the wind farm was situated. The effects were more marked under higher flow conditions. It is hypothesised that this reflects changes in hydrological processes with increased near-surface runoff or organic acid mobilisation. There was no indication that either invertebrate community structure or fish densities were impacted by construction and the resulting effects on water quality.
We are grateful to Pauls Hill Wind Ltd for supporting the monitoring programme. The authors would like to thank Ballindalloch and Tulchan Estates for access to the sampling sites and to all members of the MS Freshwater Environment Group who collected and identified invertebrate samples and provided expert hydrochemical analysis. The provision of the discharge data from the Scottish Environment Protection Agency (SEPA) is gratefully acknowledged. We are also grateful to the staff from the Spey Foundation and Spey Fishery Board for their assistance, in particular Steve Burns (Spey Foundation) for his dedication to collecting water samples in all weathers.
- Water quality
- Wind farm