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                                                                                                                  CALIBRE CONSULTING




4.4.4.3 WETLAND NODE

The wetland treatment node within MUSIC has been used to represent the constructed wetland in the central
basin. A summary of the wetland details used to configure the treatment node is presented in Table 4-4 below.

                                             Table 4-4: Wetland Treatment Node Details


                                                   Parameter                       Central Basin
                                     Surface Area (m²)                                    1700
                                     Extended Detention Depth (m)                           0.4
                                     Permanent Pool Volume (m³)                           1072
                                     Evaporative Loss as % of PET                           0.0
                                     Equivalent Pipe Diameter (mm)                          41
                                     Notional Detention Time (hrs)¹                       76.3
  ¹Note: Notional Detention time of 76.3. (Approximately 3 days) is to allow for the Central Basin to be topped up from treated water from the
                                     Northern Basin. Refer to Drawing No. B14158.W – SK05 for details.


4.5        MUSIC MODELLING RESULTS
Results for the proposed stormwater quality management strategy is presented in Table 4-5 below.

                                                 Table 4-5: MUSIC Modelling Reports


                                                                TSS                 TP                TN           Gross Pollutants
      Description                                              (kg/yr)            (kg/yr)           (kg/yr)            (kg/yr)
    Developed Site Only (Without Mitigation)                    17600              52.7               370                  3170
    WQOs (Percentage Reduction)                                  80%               60%               45%                    90%
    Load Retention Target                                       14080              31.6               167                  2850
    Developed Site plus External Catchment
                                                                24600              65.1               427                  3430
    (Without Mitigation)
    Developed Site plus External Catchment
                                                                10400              32.4               255                     0
    (With Mitigation)
    Load Retention Achieved                                     14200              32.7               172                  3430
    Load Retention Achieved as % of
                                                                 81%               62%               47%                   100%
    Developed Site Load
    Objective Achieved?                                          Yes               Yes                Yes                   Yes

The above results indicate that the proposed strategy is effective in treating pollutant loads from the proposed
development to achieve the WQO’s as required under Healthy Waterways WSUD – Technical Guidelines for SEQ (2006)
and SPP 2014.




B14158.W-01A | COOROY RETIREMENT COMMUNITY| PALM LAKE RESORTS                                                                                |9