Landslide Hazard Report_compressed

Specialists in transport geotechnics

5 PROPOSED DEVELOPMENT IMPACT ASSESSMENT

5.1 Site layout
Please refer to Appendix 1 for the layout and contour plans.

5.2 Proposed development components
The proposed development at 416-411 Black Pinch Road Cootharaba involves the construction
of a dwelling on an undeveloped property.

5.3 Roadworks, Driveways and other Pavements
No detailed plans have been provided at this stage of assessment. It is recommended that
pavements should be tied neatly into adjacent ground and minimise any potential for
concentrated flow paths to be generated onto adjacent land surfaces through the use of swale
drains.

5.4 Earthworks
Based on the development plans provided it there is minimal earthworks required for the
construction of the dwelling which is to be founded above ground on piers.
Should earthworks be required it is recommended that the fill operations be undertaken with the
appropriate engineering supervision to ensure compaction is achieved. Any fill batter on the down
slope side of the house will require appropriate batter angles/retention systems to ensure the
stability of the fill platform and house foundations.

5.5 Foundations
No structural details have been provided at this stage of assessment besides to architectural
plans. It is assumed the foundations would comprise piered stumps to support the house. It is
recommend that piers found at depth in the underlying hard residual soils. As a minimum, good
hillside design practices as defined in AGS (Refer to Appendix 3) are recommended for this site.

5.6 Surface drainage
Surface details for the proposed development, levels are currently only available on approximate
architectural drawings. It is recommended that swale drains be constructed to direct flow around
the house and to slow and dissipate flow down the slope to ensure flow is kept away from the
house.

5.7 Wastewater treatment and disposal
Details of the wastewater treatment facility are beyond the scope of this report.

5.8 Overall effect of development on stability
It is considered that the proposed development has the potential to have a Low impact on the site
given its current condition. Implementation of engineering controls outlined in Section 6 should be
incorporated to reduce the long term and short-term risk. Inspection, monitoring and maintenance
should be undertaken at a minimum to ensure the site stability into the future.




10 May 2022                       CGC-SR-2022-011-R01-Rev01                               Page 13