Environmental Engineering Reference
In-Depth Information
result from a decision, determining acceptable risk is an issue of risk management
(MoE
2000
). The risk assessment is a basis for judgments about impacts themselves,
but not for judgments on the acceptability of impacts. MoE (
2000
) consider that
there are two main limitations to an environmental risk assessment: risk tolerance is
relative, and that the range of natural variability within ecosystems will result in
differing tolerances to stress, and varying rates of recovery.
The examples provided in this paper were aimed at avoiding risk through qualita-
tive assessment and mapping within a development envelope of the signifi cant local
resources; or the management of quantifi ed risk through modelling of potential out-
comes of proposed wind farm development. In both cases the management of asso-
ciated risk can be furthered through a variety of agreed mitigation measures or more
adaptive approaches. For example, where there are quantifi ed potential bird collision
risks a number of on-site mitigation measures have been suggested to reduce collision
fatalities at operational wind farms (e.g. bird scaring devices, high contrast patterns
or UV paint on blades, use of fl ight-diverter refl ectors, and installing transmission
cables underground e.g. Drewitt and Langston
2006
,
2008
), almost all have yet to
be tested in the fi eld to determine their effectiveness. Off-site mitigation measures
could involve habitat management to encourage birds to use sites away from wind
farms and/or to improve adult survival or fl edgling production (Walker et al.
2005
).
Where constraints have been applied to a potential wind farm site it is possible to
avoid impacts or provide adaptive management processes to move management
away from single event assessment and management decisions with an implicit
notion of a static world (Hollings
1978
), and to actively manage an ecosystem,
adapting management plans over time until desired outcomes are achieved.
Acknowledgements
We thank Meridian Energy Ltd. and Trust Power Energy Ltd. for permission
to use data from their respective wind farm resource consent applications. We are grateful to the
many landowners who granted access to their land in order to gather the data and information
presented in this paper. We thank the many fi eld assistants who have tolerated long days in all
conditions who persevered to collect samples and data; in particular Roland Payne, Rob Jessop and
Richard Allibone for their assistance at the Mahinerangi Wind Farm, and Richard Seaton and
Becky Bodley for their assistance at the Hurunui Wind Farm site. The manuscript was improved
by the insights of independent referees to whom we are grateful. Falcon trapping and radio tracking
was conducted under Department of Conservation permits 0285 and CA-27062-FAU.
References
Anderson, W.L., D. Strickland, J. Tom, N. Neumann, W. Erickson, J. Cleckler, G. Mayorga,
A. Nuhn, A. Leuders, J. Schneider, L. Backus, P. Becker, and N. Flagg. 2000. Avian monitoring
and risk assessment at Tehachapi Pass and San Gorgonio Pass wind resource areas, California:
Phase 1 preliminary results, 31-46. In
Proceedings of National Avian-Wind Power planning
meeting III
, San Diego, California, May 1998. Unpublished report prepared for the Avian
Subcommittee of the National Wind Co-ordinating Committee by LGL Ltd, King City, ON.
Anon. 2009. HB AS/NZS ISO 31000:2009.
Risk management - Principles and guidelines
.
Australia and New Zealand ISO 31000:2009.
