25289-001-Rev0 - The Esplanade (1)-compressed

Groundwater seepage may develop at shallower depths, particularly following periods of prolonged or
heavy rainfall at various levels through the dune profile, possibly being ‘perched’ of zones of indurated
sand that may exist. Based upon experience at other similar sites in the area, such seepage would be
expected to be transient and of relatively minor lateral extent.


4.6         Geotechnical Laboratory Test Results
PSD analysis on one natural sand sample selected from borehole BH1 indicated that the soil generally
comprised poorly graded, fine to medium grained sand, that was relatively ‘clean’ (1% trace silt).
Full test results (laboratory certificate) are presented in Appendix B.


4.7         Surface Drainage
Surface drainage would be expected to follow natural surface contours to the east towards the beach.
The site has a relatively small catchment, with the majority of upslope run-off expected to be intercepted
by the neighbouring property or the roadside drainage along Stevens Street to the west.
Given the sandy nature of the site, rainfall would normally be anticipated to infiltrate the ground surface
relatively quickly. However, as the proposed development will occupy the majority of the block,
significant run-off from hard surfaces will occur. Nevertheless, where directed into swales rather than
pipes, such run-off would be expected to infiltrate into the natural sands relatively rapidly. No significant
surface water run-off features were noted across the allotment or adjacent dune face during our
assessment (e.g. scour/wash out scars).




Geotechnical investigation
19 November 2025 | 25289-001-Rev0                                                                           9