OPW052025 Report - Part 2

To the west of the alignment, a short section of about 60 m length was cut sidelong into the northern
flank of the main ridgeline. The cutting was around 2 m to 3 m in height on the upslope side of the track
and had been left at about 45°. To the northern side of the track at this location, a slightly steeper
ground slope of 18° was noted within 3 m of the edge of the track, which would be consistent with the
alignment being off the crest. Within 6 m of the track, a gully head developed, where ground slopes of
about 27° were measured.
Within the wider northern drainage feature, well downslope of the track, an area of irregular ground was
noted in the contours and observed to be so on site. This type of topography (i.e. where contours
reverse) is an indicator of historic landslide activity, and a number of areas of ‘hummocky’ ground,
leaning trees and exposures of colluvium (ancient landslide deposits) were seen through this area (Ref.
Text Figure 3 on the preceding page).
The site of the proposed house consisted of a relatively wide, gently sloping knob crest; of at least 20 m
width at around 5°. Around 10 m from either side of the proposed construction ground slopes increased
to about 10° to 11°, developing to 15° and steeper downslope. The area around the crest and flanks of
the knob were noted to be relatively consistent, with no signs of previous landslide movement observed
(e.g. irregular or ‘hummocky’ ground, tension cracks, adverse drainage conditions).
General views of the site are given in Text Figures 4 to 6.




 Text Figure 4: Veiw from lowest intermediate knob (LHS) & along driveway alingment above existing
                                            sheds (RHS)




Geotechnical Investigation & Slope Stability Assessment
9 April 2025 | 25050-001-Rev0                                                                            5