Amended Stormwater Plan · MCU18/0019

SC7440 – Goodchap St, Noosa                                                                            7




3.3.1   Water Quality Objectives
The water quality objectives (WQO’s) for this site were determined in accordance with Appendix 2 of the
State Planning Policy (SPP) Dec 2016.


Table 3.2 indicates the minimum load reduction targets required to be met:


                                  Pollutant                 Minimum Reduction Targets

                    Total Suspended Sediments (TSS)                    80%

                          Total Phosphorus (TP)                        60%

                              Total Nitrogen (TN)                      45%

                         Gross Pollutants (>5mm)                       90%

                                         Table 3.2 - Water Quality Objectives


3.3.2   Catchment Areas
Table 3.3 illustrates the proposed roof, carpark/hardstand, and landscape areas to be treated as part of the
development site.



                                                                     % Impervious
                                                                      (Per MUSIC
                  Node                        Description                              Area (Ha)
                                                                       Modelling
                                                                      Guidelines)
               Combined                             Roof                  100            0.400
           Post-development            Carpark/hardstand areas            100            0.085
              Catchments                      Landscape                      25          0.189
                              Total MUSIC Model Catchment (Ha)                           0.674
                          Table 3.3 - Post Development Sub–Catchment Areas



3.3.3   Pollutant Export Modelling
The Model for Urban Stormwater Improvement Conceptualisation (MUSIC) has been utilised to calculate
pollutant loads from the proposed development and to predict performance characteristics of the proposed
treatment train. Modelling parameters used were adopted from the Water by Design “Music Modelling
Guidelines for South-East Queensland”, and the updated MUSIC Version 5 recommended parameters for
Bio-retention basin nodes. MUSIC modelling setup and results are attached within Appendix B.