Reference Document - MCU24/0143 (As Published)

        3.2          Stability 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 1, and the
        Qualitative Terminology for Use in Assessing Risk to Property is attached.

        Table 1: 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.

        To assist with our slope stability assessment, Tectonic was provided with the following information by the
        client:
                The value of the property would be in the range of $3M to $3.5M, based on sales nearby.
                The tiny homes would add around $500,000 to $600,000 value to the property.
                To relocate one of the tiny homes, the estimated cost would be around $50,000 to $100,000.
        Based on the approximate value of the property, including the improved value based on the tiny homes,
        we have estimated the approximate cost of damage should one of the homes require relocating due to
        landslide movement would be between about 1% to 3% of the overall property value.
        Considering the site conditions as observed over time, including during the recent site visit following a
        period of heavy and prolonged rainfall (Ref. Section 2), and subject to the implementation of
        recommendations given in Section 4, it is assessed that there would be a Low (L) Risk of global slope
        instability affecting both cabins.
        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 2 overleaf is our qualitative
        assessment of landslide risk for the cabins. A summary of qualitative terminology for use in assessing
        risk to property is attached (taken from AGS 2007). Given the slow-moving nature of the existing
        landslide down slope from the northern cabin, and low likelihood of people occupying the tiny homes
        during heavy rainfall events, it is assessed that there would be a Tolerable risk to people in both cabins
        from landslide movements.
        This assessment excludes geotechnical risk associated with other parts of the site away from the existing
        tiny homes area.




        4 June 2025
        24378-001-Rev1                                                                                                                        10 of 12
Document Set ID: 24125427
                  24010296
Version: 1, Version Date: 17/09/2025
                          07/08/2025