Attachment D - Stormwater and Water Quality report

                                                                                  Callaghan & Toth

TABLE 4.1          MUSIC CATCHMENT AREAS (DEVELOPED)

                      Catchment                         Land Use           Music           Area (ha)
                                                                         Impervious

                    Adjacent Industrial Catchment – former Lot Reconfiguration Model
Catchment 1a – Lots Future, 1, 2, 3 East & 4             Industrial           65%               0.68
Catchment 1b – Lots Future, 1, 2, 3 East & 4 Roof          Roof              100%               0.25
Areas
Catchment 1c – Road Reserve North                       Commercial            35%               0.28
Catchment 2a – Road Reserve South West                  Commercial            35%               0.08
Catchment 2b – Road Reserve South East                  Commercial            35%               0.10
Catchment 5a – Lot 3 West                                Industrial           65%               0.44
Catchment 5b – Lot 3 West Roof Area                        Roof              100%               0.05
TOTAL                                                                                           1.88
                           EXISTING & PROPOSED AREAS ON LOT 5 AND LOT 7

Catchment 6 – Camphor Shed and carpark                   Industrial          90%                0.06

Catchment 7 - Existing carpark + driveways –                                 100%              0.197
                                                         Industrial
formalising area

Catchment 8 – new pathway                                Industrial          90%               0.014

Catchment 9 – new access road                                                90%                0.06

Catchment 10 – new carpark area                                              90%                0.12

Existing grassed area used for informal carparking                           20%                0.24

TOTAL                                                                                          0.69ha


4.3.2 Treatment Nodes

The “MUSIC Modelling Guidelines for South East Queensland” Version 1.0 prepared by Water
by Design and dated December 2010 has been used to set the rainfall runoff parameters and
pollutant export parameters for the site.

The land use type used for this model was “Industrial” and the values in the guideline shown in
Table 3.7 and Table 3.8 of the guidelines have been used in this model. Figure 4.1 shows the
MUSIC Model layout for the site. Refer to IPWEAQ standard drawings WSUD 001 & WSUD
003 ( See Appendix C)
Bioretention Basins the existing biobasin in Lot 7 constructed in 2005 will continue to treat flows
from the existing carpark and hardstand areas and from the new proposed carpark, landscaped
areas, and pathways. The existing Biobasin in Lot 7 is 12m x 12m with a total filter area of
144m2. The existing biobasin adjacent Mary River Road is 3m x 8.65m with a total filter area of
26m2. This treatment node has been updated to Version 6.2.1 MUSIC model node and has
been amended to reflect the proposed design changes to the biobasin detailed in Section 6.0.




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2001 Lower Mill Carpark Extension SWMP                                         February 2020