Response to Information Request - MCU12/0184

Geotechnical and Slope Stability Investigation




           Treatment options to reduce to low risk should be implemented as soon as practicable.

The decision as to the level of risk to be accepted or tolerated needs to be considered by the owner,
consent authorities, insurance companies and other parties involved. The decision should be based on

a number of    factors, not limited to: the cost of repair of structures, the legal ramifications of accepting
the risk, the effect of the consequences on people, and the future implications of damage to the
structure. Ultimately the decision to accept or remediate the risk is taken by the owner of the site. The

following section presents a summary of the slope stability hazards and a slope stability risk
assessment for the site.


7.5         Identification of Hazards

The proposed subdivision currently does not contain any building structures. For the purpose of this

assessment, it has been assumed that the future residential building development will comprise a
lightweight clad timber frame structure. The instability hazards judged to potentially present at this site
include:

           1: Shallow failure in the footing zone of the future structure.

           2: Deep failure through the weathered rock below the future structure.

           3: Failure of engineered retaining structures or cut and fill batters on the site.


7.6         Property at Risk
The property at risk in this assessment is considered to be the permanent poultry sheds, water tanks
and hoppers described in Callighan & Toth drawing no, 1209-A1.


7.7         Results of Risk Assessment

The assessed likelihood and consequences of the three relevant hazards are presented in Appendix D.
A summary of the assessed risks are shown in Table 1.

The assessed risk as indicated in Table 1 assumes the recommendations regarding building
foundations and geotechnical structures in this Coffey report are followed. Where the
recommendations are not adopted, or only adopted in part, the assessed risk may be different to that
indicated in Table 1.




Coffey Geotechnics                                                                                               5
GEOTKPAR01945AA1A
23rd April 2013