Appendix D - Geotechnical Report

6.           Slope Stability Assessment
6.1          Existing Conditions
NC landslide susceptibility mapping (Ref. Text Figure 12) indicates that extensive parts of the site are
affected by areas denoted as Moderate to High susceptibility.




                                                                                       Existing overall lot boundary




                     Text Figure 12: Extract from NC landslide hazard overlay mapping

It should be noted that the NC mapping is a broad-scale indication of the potential landslide
susceptibility only and is superseded by this site-specific assessment.
The site did not exhibit any visible indicators of global slope instability at surface (e.g. tension cracks,
unusual landforms, 'hummocky’ ground or the like). Proposed lots 1 and 5 were dominated by well
defined, rounded spur crests, which extended up to the road frontage with Black Mountain Range Road.
This type of morphology is favourable from a slope stability perspective. A building area on the crest of
the spur to the centre of Lot 2 could also be established, where access can be created in accordance with
the recommendations contained within Section 7 of this report. The building location to the south-west
of proposed Lot 2, and over the southern part of Lot 4, were located on relatively broad, linear slopes.
While moderately steep, with appropriate controls and limitations applied (per Section 7 of this report)
building in these locations would be feasible.
The subsurface conditions included very stiff to hard residual soils and XW materials from surface, and a
consistently shallow ‘rockhead’ at all test pit locations.




Geotechnical Investigation
10 June 2026 | 26073-001-Rev0                                                                                    13