Appendix J - Civil Engineering Report and SBSMP

                                                                                      Noosa Residential Development
                                                                               Ref: 24553 C R002 REV03 10.08.21.docx
                                                                                                         August 2021

7.4.1    Bioretention Basins

            Catchment B1: A minimum 80m2 bioretention basin (area measured at surface area).
            Catchment B2: A minimum 45m2 bioretention basin (area measured at surface area).

         Bioretention basins remove contaminants and sedimentation from stormwater runoff via infiltration
         through layers of soil media. The basin is made of a 400mm filter media layer and a 100mm transition
         layer located above in-situ soil. The basin is to be vegetated by plants with root bases to suit the filter
         depth, as per the landscape architect’s recommendations. These plants provide additional treatment
         and will reduce the clogging of the basin. Runoff within the bioretention area gradually infiltrates the
         soil layers, before discharging via sub surface drainage pipe. This pipe will discharge to the natural
         surface with scour control as detailed in QUDM.

7.4.2    Swale drains
         Grassed swales halt the movement of sediment lad runoff by slowing velocity and providing natural
         filtration. As such, removing water pollutants and improving water quality to meet the required
         treatment objectives mentioned in this report and ensure the prevention of sediment transportation.
         Grass-lined swales are to be used across the development site to augment the bioretention basin.

         A conceptual arrangement of the proposed grass line swales system can be seen in the ADG
         Stormwater Quality Plan SK02 in Appendix C.

7.5      MUSIC Model
         The sites stormwater run-off for the development was modelled using MUSIC (version 6.3.0) and the
         water quality objectives for South East Queensland specified in the SPP 2017 of 80% TSS reduction,
         60% TP reduction, 45% TN reduction, and 90% Gross Pollutants reduction.

         The results shown in Figure 4 meet the percent reduction water quality objectives identified by Noosa
         Shire Council standards and the SPP 2017.

         Details of the MUSIC model are attached within Appendix I for further information.

         Refer to Appendix C for the Preliminary Layout Plans prepared by this office.




BRISBANE / SYDNEY / MELBOURNE / GOLD COAST / SUNSHINE COAST / DARWIN / PERTH                                Page 18