Appendix D - Geotechnical Report

6.2             Slope Stability Assessment
6.2.1           Qualitative Assessment
The risk assessment for this project has been carried out following AGS 2007 Practice Note Guidelines for
Landslide Risk Management. Relative levels of risk and their implications are given in Table 2 and the
Qualitative Terminology for Use in Assessing Risk to Property which is also attached in Appendix C.

Table 2: Stability Risk Levels
 Risk Level                     Example Implications     (1)




 VH        Very High Risk       Unacceptable without treatment. Extensive detailed investigation and research, planning and implementation
                                of treatment options essential to reduce risk to Low; may be too expensive and not practical. Work likely to
                                cost more than value of property.

 H         High Risk            Unacceptable without treatment. Detailed investigation, planning and implementation of treatment options
                                required to reduce risk to Low. Work would cost a substantial sum in relation to the value of the property.

 M         Moderate Risk        May be tolerated in certain circumstances (subject to regulators’ approval) but requires investigation, planning
                                and implementation of treatment options to reduce risk to Low. Treatment options to reduce to Low risk
                                should be implemented as soon as practicable.

 L         Low Risk             Usually acceptable to regulators. Where treatment has been required to reduce the risk to this level, ongoing
                                maintenance required.

 VL        Very Low Risk        Acceptable. Manage by normal slope maintenance procedures.
Note: (1) The implications for a particular situation are to be determined by all parties to the risk assessment and may depend on the nature of
the property at risk; these are only given as a general guide.

Considering the existing site conditions, and subject to the implementation of recommendations given in
Section 7, it is assessed that there should be a Low Risk of global slope instability affecting the proposed
subdivision. Regulators (NC) normally require that a Very Low or Low Risk of landslide affecting property
must be demonstrated to enable development approval. Summarised in Table 3 overleaf is our
qualitative assessment of landslide risk. A summary of qualitative terminology for use in assessing risk to
property is attached in Appendix C (taken from AGS 2007).




Geotechnical Investigation
10 June 2026 | 26073-001-Rev0                                                                                                                   14