Slope Stability Report 26-5-2019 OPW19-0193

TRUBUILT
SLOPE RISK ASSESSMENT REPORT



2.         DESKTOP STUDY AND DESCRIPTION OF SITE CONDITIONS

2.1        Regional Geology

The regional geology of most of the site comprises the Early to Mid Triassic Age Kin Kin Beds which comprises
arenite, argillite and phyllite. Part of the north-western corner of the site comprises Tertiary Age Basalt which
comprises mostly olivine basalt flows and some plugs; some areas of nephelinite, basanite etc. (QLD 2011)

It is noted that the basaltic material tend to be located along the ridge tops and generally comprise red clay
with boulders of basaltic rock. This material is underlain by weathered Kin Kin Beds.


2.2        Investigations by Others

Drilling for the site classification and effluent disposal was undertaken by Global Testing, but the results of this
drilling was not available at the time of writing.


2.3        Site History

A summary of the site history was gleaned from public domain aerial photography and GIS data of the site
sourced from Google Earth, QImagery data, Queensland Globe and Noosa Shire Council online mapping
application. There are a number of photographs of the site of various quality and resolution dating back to
October 1953. The following is a summary of the development of the site:

      •   In October 1953 about 75% of the site was cleared of trees and converted to grass land with minor
          areas of cropping. There were some buildings in the middle west of the site with an access road
          following the creek back to Upper Pinbarren Creek Road;
      •   By January 1958 over 90% of the vegetation had been cleared from the site, with remnant vegetation
          confined to ridges and the upper parts of southward facing slopes;;
      •   By December 1967, it appears that some of the vegetation had started to grow back;
      •   By January 1974, the remaining vegetation along the ridges and upper slopes had been cleared but
          thick vegetation was growing around the creeks. A small track was present at the location of Ewarts
          Road, but the main access was along the track about halfway down the site. Buildings are present
          near the main creek;
      •   By January 1979, the buildings had been removed from the property and the main access track
          appears to have been abandoned. Some of the vegetation around the creeks have been cleared and
          scattered trees are growing on the slopes. The eastern boundary of the site is clear due to
          differences in clearing and grass growth;
      •   In August 1984 a track had been pushed along the main creek to the position of the current
          residence, with buildings at this location. It appears that the cut and fill pad at this location was
          constructed at this time;




LEONTAKIANAKOS-R-001                                 Page 3                                              26 May 2019