Reference Document - MCU24/0023

GJ Gardner Homes Gympie                                                                          23236-001-Rev0
C/- Covey Associates Pty Ltd                                                                       7 August 2023

3.0     ASSESSMENT OF LAND STABILITY
3.1   Existing Conditions
The Noosa Planning Scheme 2020 includes a landslide hazard overlay map (Ref. extract in Text Figure 10)
which indicates that the proposed development area and immediate surrounds have a Very Low/Low
Landslide Hazard. Most of the remaining areas of the site are mapped as having Moderate to High
Landslide Hazard.




                                                                                 Site boundary




                                                    Proposed building location




Text Figure 10: Extract from NC Landslide Hazard Overlay Mapping

It should be noted that the NC map is a broad-scale indication of the potential landslide susceptibility only
and is superseded by this site-specific assessment. At the time of our visit, the proposed residence area
did not exhibit any indicators of global slope instability. No landslide back scarps, groundwater springs,
tension cracks, or areas of naturally ‘hummocky’ ground were observed across the hill crest however the
natural slopes below were, in places, very steep particularly in the drainage or gully lines. In these areas
where surface drainage was poor, there was evidence of previous slope instability.
There is potential for such slope movements to regress upslope which could put the residence at increased
risk of instability. This is particularly relevant in the south-eastern part as the building pad appears to have
been formed by filling above steep ground with a landslide backscarp in that area (Ref. Text Figure 11).
Measures to mitigate and reduce the risk of instability are given below in Sections 3.2 and 4.




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