4. 220148 - Slope Stability Report (2) · 132006.2554.01

Seachange Builders                                                                           22134-001-Rev0
                                                                                                26 April 2022




Text Figure 6: Property frontage, undergoing demolition at time of assessment

2.3    Groundwater
No signs of groundwater seepage (‘springs’) were observed during our walk-over, nor was groundwater
mentioned in the CSI borehole report.

2.4    Surface Drainage
Surface drainage would be expected to follow the contours to the east. However, run-off would be minimal
due to the sandy nature of the soils at the site, and is currently interrupted by the existing residence,
terracing and landscaping features.

It is acknowledged that a surface water catchment for the site exists to the west; however, most of the
stormwater to the west of the property is anticipated to be intercepted by the existing stormwater
infrastructure along Tristania Drive. Given the sandy nature of the site and surrounds, rainfall would
normally be anticipated to infiltrate the ground surface. However, as the existing residence and proposed
renovations will occupy a large part 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 evidence of significant erosion was observed across the subject site.
Two field inlets pits for stormwater discharge were observed along the rear (eastern) boundary.

2.5    Vegetation
The ground surface around the existing residence primarily comprised areas of short grass which were
fringed by scattered shrubs and juvenile trees. The beach reserve to the east was densely vegetated.

2.6    Buildings and Other Structures
The existing residence is a three level, rendered masonry structure. Most of the ground surface surrounding
the residence was levelled by previous earthworks, supported by grouted rock or blockwork walls. Based on
an external assessment, most of the visible areas of the existing structures and retaining walls appeared to
be in good condition and did not exhibit any signs of significant distress (e.g. cracking, misalignment, etc.)
which could be attributed to slope instability. Minor hairline cracking was observed in the building render.
The existing pool was empty of water and appeared free from cracking.

Some cracking was observed along the grouted rock retaining wall along the eastern edge of the existing
pool, however we understand that these structures are to be demolished.




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