Slope Stability Report

Dean & Vanessa McDonald                                                                       21505-001-Rev0
                                                                                              4 February 2022

3.0     ASSESSMENT OF LAND STABILITY
3.1   Existing Conditions
As illustrated in Text Figure 11, NC’s landslide hazard overlay map indicates that the proposed shed site has
a Moderate (pale yellow shading) landslide susceptibility, whilst areas across the site (typically gullies) are
mapped as having a High (orange shading) landslide susceptibility.




                                                                 Proposed Shed Location




Text Figure 11: Extract from NC Landslide Hazard Mapping

It should be noted that the NC map is a broad-scale indication of the potential landslide susceptibility and
is superseded by this site specific assessment. The site did not exhibit any indicators of global, natural
slope instability at the time of our inspection. No landslide back scarps or areas of naturally ‘hummocky’
ground were observed in the vicinity of the proposed building area, with residual soil and exposed rock in
existing cut batters.

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




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[OCR of page images]
Dean & Vanessa McDonald 21505-001-RevO
4 February 2022

 

3.0 ASSESSMENT OF LAND STABILITY
3.1. Existing Conditions

As illustrated in Text Figure 11, NC’s landslide hazard overlay map indicates that the proposed shed site has
a Moderate (pale yellow shading) landslide susceptibility, whilst areas across the site (typically gullies) are
mapped as having a High (orange shading) landslide susceptibility.

MM Very High Hazard Area
4

WB High Hazard Area

Moderate Hazard Area

¥

 

Text Figure 11: Extract from NC Landslide Hazard Mapping

It should be noted that the NC map is a broad-scale indication of the potential landslide susceptibility and
is superseded by this site specific assessment. The site did not exhibit any indicators of global, natural
slope instability at the time of our inspection. No landslide back scarps or areas of naturally ‘hummocky’
ground were observed in the vicinity of the proposed building area, with residual soil and exposed rock in
existing cut batters.

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

 

ynic

geotechnical & environmental engineers.

 

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