Reference Document - MCU26 0012 & OPW26 0034 (As Published)

1.2           Method and Scope of Investigation
As part of our slope stability assessment, a desk-top study was carried out comprising a review of
published geological maps, NC overlays, slope stability studies and a ‘soil test’ report by Australian Soil
Investigations (ASI, Ref. Report No. 250385 [S], dated 23 January 2026). An effluent disposal design
report and site evaluation were also provided (ASI, Ref. Report No. 250385 [A] dated 19 January 2026). A
walk-over survey was conducted to make an appraisal of the general condition of the site regarding
topography, drainage, vegetation cover, geology, erosion, condition of existing structures and slope
stability. The walk-over was carried out by an experienced engineering geologist from Tectonic on
9 February 2026. The results of the desk-top study and walk-over survey are included in Section 2 below.

1.3           Qualifications of Responsible Engineer
This report has been reviewed by Ashley Davey, an RPEQ with more than 30 years’ experience in
geotechnical engineering, including numerous slope stability projects.


2.            Description of Existing Conditions
2.1           Geology
A published geological map for the region1 indicates that the site is underlain by the middle Triassic age
Kin Kin Beds (dark green/blue shading); a metasedimentary unit described as “strongly cleaved and
commonly kinked mudstone with thin mudstone laminae, minor volcanilithic sandstone.” An extract of the
relevant geological mapping is shown below in Text Figure 3.




                                                                         Approx. site location




                                  Text Figure 3: Extract of Nambour Surface Geology Map

At the time of our site visit the surface across the site was relatively well maintained with established
vegetation, and lawns around the existing residence; and slashed paddocks in the surrounds. Along the


1
    1:100,000 Scale Gympie Surface Geology Map, Sheet 9445, Dept. Natural Resources, Mines & Energy, 2018


13 February 2026
26020-001-Rev0                                                                                              3 of 13