DBW21/0216 - Application For Building Works For A Dwelling House At 60 Seaview Terrace, Sunshine Beach · Attachment 1 – DBW21 0216 – Planner’S Report

                    Figure 11 – CHAP Coastal Hazards Mapping (Erosion Prone Area)

To address the known risks of instability and erosion the applicant has submitted a Geotechnical
Report and a Coastal Hazards Assessment, which have been reviewed by external consultants
(Geotechnical Engineer and Hydraulic Engineer). The submitted reports were amended after an
initial review by the external consultants and were determined to include methodology and
recommendations which appropriately address the landslide and erosion risks. The measures
proposed have been designed on the basis of a 500-year average recurrence interval storm event
and include:
•       Micro-piling along the eastern edge of the residence with piles a minimum of 11 metres in
        length at 1 metre spacings.
•       The proposed residence and any ancillary structures (including retaining walls and pools)
        must be supported by footings founded at least 1 metre into natural medium dense to
        dense (or denser) sands.
•       Excavations close to site boundaries may necessitate the installation of temporary shoring
        prior to excavation.
•       Landscaping fill to the rear of the residence shall be limited to 0.5 m high, with surcharges
        elsewhere (e.g. from structures, fill, etc.) not to exceed 10 kPa.
•       Ground vibrations during construction to be minimised and monitored.
•       Revegetation of bare slopes around the development area and improvement to the
        vegetation (e.g. with site appropriate natural species) on the natural high dune face
        downslope of the residence.
•       All collected roof water to be directed by pipes to the council stormwater system along
        Seaview Terrace.

Overall Council’s consultants conclude that the Coastal Hazard Assessment and Geotechnical
Investigation have included recommendations that will sufficiently mitigate risks to the dwelling
house from coastal hazards during the lifespan of the development.
Rooftop Terrace
The proposed dwelling house includes a circular shaped rooftop terrace on the upper level
extending out from the master bedroom. The rooftop terrace is proposed to extend 7.1 metres
seaward from the master bedroom. A large planter and void areas are proposed from the edge of
the rooftop terrace out towards the rear of the dwelling. The planter and void areas have been


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