Attachment 3 - Stormwater Management Plan 1856-SBSMP-01 v5 (December 2019) · RAL18/0023

4.3 MUSIC Modelling

MUSIC (Version 6.2, eWater), a pollutant export modelling program has been used to model
both the expected pollutant loads generated by the development and the effectiveness of
WSUD treatment options selected.

4.3.1 Split Catchment Approach

The MUSIC model is based on a split catchment approach, modeled as various catchments
representing the different surface types in accordance with the guidelines and available site
information. Split catchment surface information can be found in Table 4.2 below. The
fraction impervious was calculated from proposed sealed pavement areas, and rounded up
to the nearest 5% to account for minor adjustments in detailed design.

                           Surface Type                    % Imperviousness
                           Road Reserve                Varies (75% / 70% / 60%)
                                    Table 4.2 Adopted % Imperviousness


Table 4.3 lists the total areas for the surface type in the catchment that was used in the
model. The total area is the proposed total extent of the road reserve area. Refer to the
Catchment Plan in Appendix A demonstrating these areas within the proposed development.


                          Node                                           Area (ha)
          West Hofmann Drive (South-1)                                   0.1350

            West Hofmann Drive (North)                                   0.2247

          West Hofmann Drive (South-2)                                   0.1091

                        Road A                                           0.2424

                        Road B                                           0.4000

                    Upper Road C                                         0.2368

                    Lower Road C                                         0.3569

          North Road & Part Roundabout                                   0.2419

                      Sub - Total                                        2.5358

        Lot 11-15 Car Parks and Driveways                                0.5155

                          Total                                          3.0513
                                      Table 4.3 Surface Area of Nodes




Site Based Stormwater Management Plan                                                Page 10 of 22
1856-SBSMP-01_Version 5.0 (December 2019)