Appendices 6 SMP, 7 Bushfire & 8 Noise impact - Email 3 of 4 - MCU16/0153 & REC16/0041

                                        STORMWATER MANAGEMENT PLAN
Client: Thomco (No 2087) Pty Ltd                               Location: 215 David Low Way, Peregian Beach

4.3      MUSIC Model Parameters
The MUSIC Modelling Guidelines – South East Queensland Version 1.0 (2010) was used to source
base and storm flow concentrations and runoff generation. The model was calibrated using the
Bureau of Meteorology (BOM) data from Nambour, 1989-1998 at a 6-minute time step. This is in
accordance with Water by Design’s MUSIC Modelling Guidelines – South East Queensland Version
1.0 (2010). All source nodes were set up in accordance with this guideline, specifically for split
catchments. No routing of drainage links was adopted for the purpose of taking a conservative
approach. This approach assumes that the flow through the drainage system takes no time, which
over estimates the likely pollutant load. MUSIC version 6.2.1 was used for this assessment.
4.4      Land Use/Source Node Areas
The proposed development is comprised of short stay units, dual use accommodation apartments,
permanent residential dwellings, entrance and access roads and landscaped areas. Each catchment
has been divided into three (3) source nodes for MUSIC modelling purposes. These source nodes
include treated roof, groundcover and road/hardstand areas (Table 4).

                                    Table 4 – MUSIC Source Node Characteristic
                                                Catchment     Catchment    Catchment
                                Source Node          A             B            C
                                                 Area (ha)     Area (ha)    Area (ha)
                                Treated Roof       0.123         0.142        0.138
                                Groundcover        0.051         0.142        0.100
                                   Road            0.123         0.000        0.337
                                   Total           0.297         0.284        0.584

4.5 Pollutant Reduction Results
MUSIC modelling of the proposed stormwater treatment strategy for the development was performed
to ensure the required load based pollutant load reduction objectives were achieved for the
development as a whole.
The target reductions in stormwater pollutants are based on a comparison of an unmitigated
scenario, having no treatment on site, and the mitigated scenario, which has stormwater treatment
measures incorporated onto the site. The results of the overall site MUSIC model can be found in
Table 5. Table 5 demonstrates that compliance has been met or exceeded for all of the required
pollutant load reduction objectives required by NSC and the SPP (2016).
           Table 5 – MUSIC Results – Treatment Train Effectiveness for the Overall Site
                                                             Reduction        Target
                           Unmitigated      Mitigated
      Pollutant                                              Achieved        Reduction    Compliance
                             (kg/yr)         (kg/yr)
                                                                (%)             (%)
          TSS                 2610             507             80.6              80             Y
          TP                  4.97             1.4             71.9               60            Y
          TN                  27.1             14.3            47.1               45            Y
          GP                  296               0               100               90            Y




Covey Associates Pty Ltd                                7                                 Project No: 162042
Consulting Engineers                                                                       100949Rpt Issue A