Draft National Wind Farm Development Guidelines - July 2010

• Cumulative impacts
“Cumulative landscape and visual effects result from additional changes to the
landscape or visual amenity caused by the proposed development in conjunction
with other developments (associated with or separate to it), or actions that occurred
in the past, present or are likely to occur in the foreseeable future. They may also
affect the way in which the landscape is experienced”. 15
Scottish Natural Heritage (2005) describes a range of potential cumulative landscape
impacts of wind farms on landscapes, including:
Combined visibility (whether two or more wind farms will be visible from one
location).
Sequential visibility (e.g. the effect of seeing two or more wind farms along a
single journey, e.g. road or walking trail).
The visual compatibility of different wind farms in the same vicinity.
Perceived or actual change in land use across a character type or region.
Loss of a characteristic element (e.g. viewing type or feature) across a character
type caused by developments across that character type.
Cumulative impacts may also occur where there are no other wind farms in the area,
but by virtue of combination with other major infrastructure or large scale
developments (e.g. industrial, urban, large-scale agricultural) and/ or direct or indirect
landscape changes (e.g. vegetation clearing) which may alter the overall character
or values of an area.
The assessment of potential cumulative impacts should include proposed
developments in the region which have been approved but not yet built. Relevant
authorities may provide direction as to the extent to which proposed developments
should be considered in assessing potential cumulative impacts. There may, for
example, be different considerations for developments which have been approved,
but not yet constructed, and those awaiting development approvals.
Cumulative impacts need to be considered in relation to dynamic as well as static
viewpoints. The experience of driving along a tourist road, for example, needs to be
considered as a dynamic sequence of views and visual impacts, not just as the
cumulative impact of several developments on one location. The viewer may only
see one wind farm at a time, but if each successive stretch of the road is dominated
by views of a wind farm, then that can be argued to be a cumulative visual impact.
Cumulative impacts may be visual and aesthetic, but they can also occur in relation
to non-visual values about landscape. Non-visual values include sounds/noise,
associations, memories, knowledge and experiences or other cultural or natural
values. To give an example, locating four wind farms in a valley previously best known
for its historic wineries might change the balance of perception about the valley’s
associational character, irrespective of whether all four wind farms were sited in a
single viewshed.
• Management and mitigation
Management and mitigation refers to actions taken to reduce or eliminate impacts as
a result of the full landscape assessment and visual impact assessment. It is
imperative to note that mitigation measures are very limited for wind farm
development and therefore general location and site selection is of utmost
importance.
15 Guidelines for Landscape and Visual Impact Assessment, Second Edition, Spon Press, p85
Draft National Wind Farm Development Guidelines – 2 July 2010 Page 71