2576 - SBSMP-01 (Feb 2026)

3.3 MUSIC Modelling

MUSIC (Version 6.3.0) was used to model both the expected pollutant loads generated by the
development and the effectiveness of the proposed WSUD treatments. Rainfall, pollutant
loads, and treatment node parameters were derived from the MUSIC Modelling Guidelines
(for South East Queensland) V1.0 (Water by Design, 2010).


3.3.1 Split Catchment Approach

The development site was divided into catchments based on surface types (roof, paved,
pervious) as shown in Table 3-2. This approach allows for accurate representation of runoff
volumes and pollutant generation from different surfaces. Surface areas were calculated from
electronic CAD drawings of the development plan, consistent with the methodology outlined
in Table 3.4 of the MUSIC Modelling Guidelines.


The developed site has an average impervious area of 86%. The pervious "Mixed" surface
type (0% impervious) encompasses all landscaped and vegetated areas, accounting for their
rainfall absorption capacity.


                        Source Node Area (Ha)             Surface Type % Impervious
                        C1-Roof       0.900               Roof             100
                        C1-Hardstand  0.647               SealedRoad       100
                        C1-Pervious   0.259               Mixed             0
                        C2-Roof       0.000               Roof             100
                        C2-Hardstand  0.035               SealedRoad       100
                        C2-Pervious   0.000               Mixed             0
                      Table 3-2 Adopted areas and percentage imperviousness for the subject site




2576-SBSMP-01_Version 1.0 (February 2026)                                                          Page 8 of 23
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