Appendix B - Geotechnical Investigation Report

5.2.2 Risk Analysis
Our geotechnical assessment of the risk of instability is based on the methodology proposed by Australian
Geomechanics Society (2007c) ‘Practice Note Guidelines for Landslide Risk Management’ (Reference 1) and
the relevant site features described above.

Risk To Property
The attached Table A summarises our assessment of risk to property under existing conditions and during
and following construction.

Under existing conditions, during and following construction, Table A indicates that the assessed risk to
property is “Low” and “Very Low”. In accordance with the criteria given in Reference 1, “Low” and “Very
Low” risk levels are considered to be “Acceptable”.

Risk To Life
We have not completed a comprehensive assessment of risk to life. However, based on the indicative
probabilities associated with the assessed likelihood of instability and assuming typical temporal,
vulnerability, evacuation and spatial factors for this type of site, we consider that the levels of risk to life
under existing condition, during and following construction to be “Acceptable” in relation to the criteria given
in Reference 1, i.e. less than 1 x10-6. We note that this assumes the recommendations outlined in Section 6
below are adopted.



5.2.3 Additional Comments
It must be recognised that, due to the many complex factors that can affect a site, the subjective nature of a
risk analysis, and the imprecise nature of the science of geotechnical engineering, the risk of instability for a
site cannot be completely removed. It is, however, essential that risk be reduced to at least that which could
be reasonably anticipated by the community in everyday life and that landowners be made aware of
reasonable and practical measures available to reduce risk as far as possible. Hence, risk cannot be
completely removed, only reduced, as removing risk is not currently scientifically achievable.

In preparing our recommendations given below we have assumed that no activities on surrounding land
which may affect the risk on the subject site would be carried out. We have further assumed that all Council
buried services and other buried services within and neighbouring the site are, and will be regularly
maintained to remain, in good condition.



5.3   Geotechnical Constraints to Development
Based on the contents of Sections 5.1 and 5.2 we consider that there are no geotechnical constraints to the
proposed development. Provided the proposed development is designed and constructed in accordance
with the advice presented in Section 6, we consider that following construction, the levels of risk to life and
property will remain at “Acceptable” levels.



35891URrpt Rev1                                     7