MCU14/0024 - Response to Information Request - Attachment 3

Vegetations : Vegetation consists of grasses & scattered trees.

Slope Shape/Location : The surface profile across the allotments slope faces are generally

LINEAR PLANAR.

Drainage Fi The surface drainage is good, sub-surface drainage is good. There was
no indication of ground water seepage or rising water pressure.

Stormwater flows from upstope of the allotment will be intersected and
captured by the road reserve.

Earthworks : There is no existing earthworks apparent.

Adjacent Structures: Adjacent structures on the neighbouring properties appear to be a mix of
slab on ground and suspended timber framed floors.

Evidence of previous

Soil Movements é Surface cracks

LANDSLIP MECHANISMS

Landslip is generally defined as the movement of a mass of rock or soil down a slope.

It is generally considered to occur when the strength of the soil or rock mass to support itself is exceeded
causing movement to occur within the mass.

This loss of strength can occur as a result of numerous circumstances. These include, but are not
limited to the following:-

 

-  Siesmic Activity

-  Erosions effects such as wind or fluid scour

- Soil Saturation from rainfall events or defective drainage measures
-  Construction/Earthworks activities

- Groundwater variations/movements

- Previous Landslips

The nature of landslips vary with site specific conditions and failure mechanisms that cause the slips to
occur. Appendix B provides some diagrammatic examples of various landslips.

The speed of landslips can vary greatly from millimetres per year to a number of meters in a matter of
minutes. Once again this characteristic is governed by site specific conditions and the failure
mechanism causing the slip to occur.

The allotment is situated within a massive aeolian sand bed of Quaternary age. As a general observation
dunal horizons such as these are stable where;

- The natural slope is less than the angle of repose for sand (30°)
- Vegetation exists to protect from wind generated scour
- The drainage pattern is such that there is no risk of fluvial scour.
These horizons can become unstable when aeolian or fluvial scour erode slopes to angles greater than
30°, particularly when coincident with vegetation removal.
LANDSLIP HAZARD ASSESSMENT
For our assessment we utilize the Guidelines For Landslip Risk Management Framework as provided by

the Australian Geomechanics Society, in their journal of March 2007. Descriptions used by this
framework can be found appended to this report.

SCG Consulting Engineers 2 SCG Ref: 23277(SL)