ECM_22343520_v1_Geotechnical Investigation · 132000.200173.1

                                           PROPOSED RENOVATIONS
                                           2 ARAKOON CRESCENT, SUNSHINE BEACH

            To reduce the likelihood of further scouring and undermining of the site, we recommend the following
            regarding the scour in the south-eastern part of the site (Ref. Section 4.6):
                     If possible, diversion drainage should be upgraded/constructed upslope of the area to ensure
                      stormwater flows, including from the road, are diverted away from the high dune face and ideally into
                      the existing stormwater infrastructure along The Esplanade. Diversion drainage should not
                      discharge directly onto the surrounding dune slope which may create new scour issues elsewhere.

                     The scour should be reinstated with a cellular confinement system (e.g. ‘MiraCell’, gabions, reno
                      mattress, or similar) and rock fill appropriate to the chosen system. It will be important to undertaken
                      hydraulic analyses to confirm the estimated stormwater flow rates and suitability of the chosen
                      confinement system and rock fill type.

            Design of the stormwater system should be undertaken by a suitably qualified and experienced civil RPEQ.


            7.0        CONCLUSION
            Based on the findings of our assessment it is concluded that a Low Risk of slope instability could be
            achieved for the proposed development, subject to the following:

                     Implementation of the recommendations given in this report to prepare the preliminary design;
                     Review of the preliminary detailed design by Tectonic to confirm compliance with the
                      recommendations herein; and
                     Installing a new engineer designed and certified retaining structure supported on piles founded at
                      least 1 m into medium dense (or denser) sand, designed to accommodate an unfactored shear
                      resistance of 100 kN/m, along the eastern edge of the level area to the east of the residence.



            8.0        LIMITATIONS
            This assessment relates only to the proposed building development at the site. Slopes outside the
            proposed development area may be subject to risk of slope instability, but assessment of those matters
            was beyond the scope of our commission.

            Your attention is drawn to the document Limitations, which is included in Appendix C of this report. The
            statements presented in this document are intended to advise you of what your realistic expectations of this
            report should be, and to present you with recommendations on how to minimise the risks associated with the
            services provided by Tectonic for this project.




             24 February 2023
             Report No. 22484-001-Rev0                              19
Document Set ID: 22343520
Version: 1, Version Date: 16/03/2023