Camilty Wind Farm - Partnerships for Renewables

Camilty Wind Farm
Flood Risk
13.3.19 In the context of planning and development, the government has defined a number of flood
risk zones or levels as shown in Table 13.9 below. The table also shows government policy
on whether development is acceptable in each zone.
Table 13.9 Flood Risk Zones (Scottish Government, 2010)
Risk zone
Annual flooding
probability
Appropriate land use
Little or no risk area < 0.1% All development types generally acceptable.
Low to medium risk
area
Medium to high risk
area, within areas
already built-up
Medium to high risk
area, undeveloped
and sparsely
developed areas
0.1%–0.5% Most development types are generally acceptable unless
site specific conditions indicate otherwise. A flood risk
assessment may be required at the upper end of the
probability range (i.e. close to 0.5 %) or where the nature of
the development or local circumstances indicate heightened
risk.
> 0.5% Areas already built up may be suitable for residential,
institutional, commercial and industrial development
provided flood prevention measures to the appropriate
standard already exist, are under construction or are
planned as part of a long term development strategy in a
structure plan context. Land raising may be acceptable.
> 0.5% Undeveloped and sparsely developed areas are generally
not suitable for additional development, including
residential, institutional, commercial and industrial
development. Exceptions may arise if a location is essential
for operational reasons, e.g. for navigation and water-based
recreation uses, agriculture, transport or some utilities
infrastructure, and an alternative lower risk location is not
achievable. Land raising may be acceptable.
13.3.20 The Indicative River & Coastal Flood Map (Scotland) (Scottish Environment Protection
Agency, 2010a) does not indicate any significant flood extent within the development site.
This does not mean that there is no risk of flooding as the drainage areas of some streams
within the site are less than 3 km 2 . Such rivers are not included in SEPA’s flood map.
Flooding is shown to be limited to areas directly adjacent to the river channels, due to the
incised nature of the watercourse within the site.
Overland Flooding
13.3.21 Various degrees of overland flood risk exist in many areas in Scotland, including rural and
urban areas. Overland flooding is caused by ponding of surface water, for example due to
fully saturated soils, followed by flowing of water to lower lying areas. This flood risk can be
highly localised in nature depending on the topography (including small details such as road
kerbs etc) and the extent of natural or man-made drainage systems (including drainage
ditches etc).
13.3.22 Due to the moderately sloping topography covering the majority of the site it is likely that
overland flow could occur in various places. This may be the case, for example, in areas with
low permeability soils or in steeper sloping parts of the site. It is unlikely that these overland
flows would accumulate to the extent required for significant flooding to occur.
March 2013
13-12
Copyright Partnerships for Renewables Development Co. Ltd 2013 ©
Hydrology, Hydrogeology and Ground Conditions