RFI - Attachment 5 - Amended Stormwater Management Plan · MCU22/0094

 31 March 2023


5.4.3.2 Rainfall
The rainfall data used in the model was based on the Bureau of Meteorology data from rainfall
station 40059 Cooroy Composite. The model was run for a 10-year period from 1 January 1973 to
31 December 1983. The modelling time step was 6 minutes.

5.4.3.3 Rainfall Runoff Properties
In accordance with the recommendations of Water By Design’s MUSIC Modelling Guidelines for
South East Queensland rainfall runoff properties for commercial areas have been used.

These are listed in Table 1.


 Parameter                                                                                    Value


 Rainfall Threshold (mm)                                                                          1

 Soil Storage Capacity (mm)                                                                       18

 Initial Storage (% of capacity)                                                                  10

 Field Capacity (mm)                                                                              80

 Infiltration Capacity Co-efficient a                                                             243

 Infiltration Capacity Co-efficient b                                                             0.6

 Initial Depth (mm)                                                                               50

 Daily Recharge Rate (%)                                                                          0

 Daily Base Flow Rate (%)                                                                         31

 Deep Seepage (%)                                                                                 0
                           Table 1 – MUSIC Rainfall Runoff Parameters (Commercial)

5.4.3.4 Pollutant Export Parameters
Specific Pollutant Export Parameters must be applied to each node type as cited in the Water By
Design MUSIC Modelling Guidelines. The values shown in Table 2 are for split catchment
commercial areas. Runoff pollutant concentrations are generated stochastically from the defined
mean and standard deviation.




 Excellence with Economy in Engineering                                                                 9
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