geotech

                              PROPOSED UNIT DEVELOPMENT
                              9 BOTTLEBRUSH AVENUE, NOOSA HEADS

Recommendations to improve surface drainage as part of the development works are provided in
Section 6.5.

5.0      SLOPE STABILITY ASSESSMENT
5.1      Existing Conditions
The Noosa Planning Scheme 2020 includes a landslide hazard overlay map (Ref. extract in Text Figure 8).
Mapping indicates that the site is within a Moderate (pale yellow shading) to High (orange brown shading)
Landslide Hazard Area.




                                                             Lot boundary




Text Figure 8: Extract from NSC landslide hazard overlay mapping

It should be noted that the Noosa landslide hazard map is a broad-scale indication of the potential
landslide susceptibility and is superseded by this site-specific assessment. Our observations of surface
features relevant to this slope stability assessment are summarised as follows:

       The existing residential building was noted to be in good structural condition based on an external
        assessment and showed no signs of instability (e.g. no significant cracks in rigid walls etc.).
       An upslope timber sleeper wall was heavily distressed, likely a result of age and poor construction
        rather than global slope instability.
       No indicators of recent global slope instability were observed, i.e., no landslide scarps or ‘hummocky’
        ground was evident across the proposed building area.
       No signs of groundwater seepage ‘springs’ were observed across the proposed development area.




13 July 2021
Report No. 21169-001-Rev0                                6