Geotechnical Report

                            PROPOSED UNIT DEVELOPMENT
                            31 BOTTLEBRUSH AVENUE, NOOSA HEADS

3.0      METHOD OF INVESTIGATION
As part of our assessment, a desk-top study was carried out comprising a review of published geological
maps, slope stability studies as well as Noosa Shire Council (NSC) planning overlays and site information.

An experienced geotechnical engineer from Tectonic undertook a site walk-over on 2 December 2020 to
visually assess any indicators of past slope instability. The walk-over included assessment of soil
exposures, surface drainage conditions, topography, evidence of erosion or past instability, and vegetation
coverage/condition.

This was incorporated with a subsurface investigation comprising the drilling of boreholes at two locations.
The boreholes, designated BH1 and BH2, were hand augured at the front and rear of the property to depths
of 3 m and 5 m below ground (BGL), respectively. In-situ testing, using the dynamic cone penetrometer
(DCP) method, was carried out from the ground surface adjacent to and within each borehole with the testing
extended below the base of the boreholes to depths of 3.8 m and 5.4 m BGL in boreholes BH1 and BH2
respectively. The boreholes were backfilled on completion with spoil arising during drilling, with excess
material slightly mounded at surface.

Laboratory testing was not warranted due to the sandy nature of the subsurface conditions encountered.

Reports of the boreholes and explanatory notes are attached. Test locations are shown in Text Figure 1
above. The results of the desk-top study and walk-over survey are included in Section 4 below.


4.0      RESULTS OF INVESTIGATION
4.1      Site Description
The subject site comprised an allotment described as Lot 136 on RP88934, covering an area of 506 m2 (Ref.
Text Figure 2 below). The site had frontage to Bottlebrush Avenue to the south west with access via a
concrete driveway crossover. Surrounding properties comprised residential housing to the north, east and
west with a shopping complex situated south east of the property.

At the time of the investigation there was an existing two-story residence situated in the central part of the
allotment. The existing dwelling was built into the slope with construction comprising masonry blockwork with
a lightweight roof. There was existing masonry blockwork retaining walls at the front and rear of the
property. Wall heights varied from about 1 m up to a maximum of 3 m high (adjacent to the driveway entry in
the south-western part).




                                                                        Approx. lot boundary



                                                    BH2




                                                            Existing residence


                                 BH1




17 December 2020
Report No. 20370-001-Rev0                             2