Geotechnical Investigation Report · OPW26/0149

                                                                                                              PTG/04982 – 0001 – Rev0 – Rev0



The topography within the investigation area is defined by a ridgeline that enters the site at the southern boundary
and is trending northwest. As a result, much of the land within the investigation area comprises the northeast flank of
the ridge, and is gently to moderately sloping at grades of between 1(v):6(h) to 1(v):4(h), as indicated in Figure 2
below.




Figure 2. Extract from Queensland Globe1 with a focus on the investigation area within the overall site, showing aerial photo, parts of overall
site cadastral boundaries, and LiDAR contours. Not to scale.



3 PROPOSED DEVELOPMENT
From the information provided 2 3, it is understood that the proposed development will comprise three separate cabins
with associated, stand-alone carport structures, and a dam.
The drawings show the cabins to be located near the crest of the ridge, just downslope of the existing access track.
Some minor earthworks, mostly in the form of excavation, will be undertaken ahead of the cabin and car port
construction, however no specific areas, or volumes of cut or fill are provided. Additionally, the drawings show the
cabins will make use of suspended floors supported on shallow pier foundations, while the car ports will utilise a
concrete slab on grade. The Site Plan drawing suggests Cabins 2 and 3 will have an associated 20,000 L rainwater
tank for domestic reuse, but that Cabin 1 will not. Despite what is shown on the drawing, it is assumed that Cabin 1
will also have the same water tank associated with it.
The dam is shown downslope, to the northeast of the cabins, and we understand that it is intended to be formed via a
combination of cut to fill earthworks. The drawings show cut and fill volumes of 946 m³ and 1,004 m³ respectively,
leaving a shortfall of 58 m³. It is assumed that the shortfall will be made up of either material won from the formation
works for the cabins, or will be imported from an off-site borrow source. Both cut and fill slopes formed to create the
dam are shown to be finished at a grade of 1(v):3(h), with the dam having a crest width of 3 m. The extent of the
proposed development is shown in Figure 3 and Figure 4 below.




2 Courtesy Pty Ltd (2026, April). Bimbimbie Cabins, Bill & Fiona Buchanan, 87 Hayward Road, Lake MacDonald. QLD. 4563. Project

No. 003. Drawing Nos. 1.1, 2.1, 2.2, 3.3.1 and 3.3.2, Revision 2.
3 Bax Engineering Pty Ltd (2026, July). Bimbimbie Cabins, 87 Hayward Rd, Lake MacDonald QLD 4563. Project No. 146-019. Drawing

Nos 001, 002, 100, 200, 201, 250, 251, 252, 253 & 300.

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