Camilty Wind Farm - Partnerships for Renewables

Camilty Wind Farm
assessment, the layout of all tracks was further improved to avoid areas of deep peat and
areas which may be prone to peat slides.
13.5 Potential Significant Effects of the Scheme Prior to Mitigation
13.5.1 This section describes the potential effects on hydrology, geology and hydrogeology that
could arise in the absence of mitigation during the following phases of the proposed wind
farm:
• Construction;
• Operation;
• Decommissioning.
13.5.2 Due to the nature of the site and the nature of the proposed development, a number of
construction and decommissioning effects are predicted to be similar.
13.5.3 The assessment of potential effects has been carried out for the proposals without any
mitigation measures in place as well as considering a range of mitigation measures. In each
case the potential magnitude is assessed.
Construction Phase
13.5.4 The most significant phase in terms of the potential effects is the construction period. This
section identifies the effects that are likely to occur in the hydrological, hydrogeological and
geological environment during construction of the proposed wind farm.
Effects on Surface Runoff Characteristics
13.5.5 Localised increases in the rate and volume of surface runoff could potentially be caused by
excavations, keyhole felling, exposure of bare soils, compaction of soils and poor design of
site drainage. As well as increasing the risk of downstream flooding, this could also alter the
water quality and hydrological regime of the site.
13.5.6 Track and turbine foundation construction works have the potential to alter the drainage
mechanisms within the site, for example through:
• Diversion of surface runoff away from natural drainage routes;
• Collection of runoff and rainfall within excavations;
• Reduction of rainfall interception in areas felled to accommodate construction;
• Reduction or increase in infiltration or percolation to groundwater; and
• Ponding of surface water through obstructions of flow paths, etc.
13.5.7 Compaction of soils may be caused by the movements of construction traffic and machinery.
This would reduce the soil permeability and therefore rainfall infiltration, and potentially lead
to higher catchment runoff rates, in particular during high rainfall.
13.5.8 Although tracks and hard standing areas will be constructed using granular material, surfaces
are likely to become compacted which is likely to limit infiltration through the track and hard
standing area bases. The total surface area that may be compacted has been calculated and
compared with the various catchments in which the infrastructure is located, as presented in
Table 13.17 below.
March 2013
13-20
Copyright Partnerships for Renewables Development Co. Ltd 2013 ©
Hydrology, Hydrogeology and Ground Conditions