RFI - Kauri St Civil RFI response · MCU22/0144

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            upstream of the walls will drain over the walls, to be collected in the internal drainage
            system to be conveyed through site.

            Where the retaining wall crosses the existing sewer, the sewer is to be bridged and
            the footings are to be designed to ensure that no load is transferred into the zone of
            influence of the pipe.

                    9. Provide amended, detailed plans of the proposed driveway and internal
                       roadways’ works clearly showing where the cross sections are taken from and
                       where the longitudinal sections apply.

            Please refer to the attached plans which provide further clarification of the driveway
            labelling and location for sections.


                    10. Clarify levels (including for retaining walls on all cross-sections), what
                        “OFFSET” in plan C55 refers to, standardise terminology and suitably cross
                        reference between plans.

            Please refer to the attached plans which provide further clarification of these details.
            Offset refers to the offset from the control line (represented by label ‘C’ or offset 0) for
            the typical cross sections. The terminology is standardised and additional labelling
            has been included to indicate height of walls and location of cross sections shown.

                    11. Provide vehicles swept paths (vehicle B99 as described in
                        AS/NZS2890.1:2004) for each unit which demonstrate that the garage
                        carparking space can be accessed in a forward gear, vehicles can reverse from
                        the space and exit the site in a total of 3 movements.

            The design has been updated and the swept paths revised to demonstrate the
            garages can be accessed by a B99 vehicle in forward gear, entering and leaving the
            site in no more than three movements. The only exception is unit one, for which a B99
            would only be able to enter and exit in three movements using a reverse entry into the
            garage, which is permitted by AS2890.1 under clause B4.3 for residential and
            domestic car parking. B85 vehicles are nonetheless able to enter and exit in forward
            gear, as shown in the attached plans.

                    12. Provided an updated SWMP with a revised stormwater quantity assessment
                       which justifies the assumed pervious site areas post-development and which
                       is consistent with the proposal plans.

            The catchment areas and stormwater management plan have been updated with the
            correct values based on the current architectural layout. With the revised areas and
            updated modelling, a larger tank of minimum 54m³ is required to provide the
            necessary attenuation for the development.




P +61 7 5211 1003           A 75 Noosa Dr, Noosa Heads Qld 4567   E [email protected]       recorconsulting.com

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                    13. Provide updated OPW plans which:
                       • fully contain the bioretention device within communal open space; and
                       • provide details of the proposed high-flow outlet from the basin and
                       downstream scour protection and flow dissipation in order to demonstrate
                       how flows will be discharged to downstream land without causing
                       concentration of flow or scour; and
                       • Revise and confirm the in-situ infiltration rate and whether this is suitable for
                       a ‘pipeless’ bioretention basin; and
                       • If a pipeless bioretention basin is suitable, revies the basin section to
                       encourage infiltration by having a flatter basin surface and provide some
                       extended detention depth.

            The updated plans provide additional information to detail the bioretention area.

            Details of the weir outlet have been provided which rely on a 1.4m wide rock spillway
            to discharge run-off at the south eastern corner of the site. Based on the survey,
            natural surface grades are typically around 5% at this location, therefore downstream
            scour is considered unlikely, and the rock outlet will assist by dissipating energy from
            the overflow and dispersing run-off from the outlet.

            Based on the previous geotechnical analysis, the soils at the location have a saturated
            hydraulic permeability of 0.0998cm/min, equivalent to 59.88mm/hour of infiltration
            capacity. The MUSIC modelling has been updated to reflect this, and in turn a smaller
            bioretention garden will achieve the required pollutant reduction targets. To
            encourage infiltration, a typical 1% surface grade to the garden has been applied, and
            200mm of extended detention depth is available below the weir spillway level.

            For further details on the other items of the information request, please refer to the town
            planning response.

            We believe that the above satisfactorily addresses the engineering matters raised in the
            information request however, should additional information be required, please contact
            our office directly.

            Yours faithfully,
            RECOR Pty Ltd

            Prepared by



            Ben Parry
            Civil Engineer
            BEng (Hons), MIEAust CPEng NER
            RPEQ: 28084




P +61 7 5211 1003           A 75 Noosa Dr, Noosa Heads Qld 4567   E [email protected]    recorconsulting.com