Att 2 SWMP

                                   Figure 4.2 - Rainfall run-off parameters for SEQ

As the existing site is largely unchanged, only the proposed additions to the site have been
modelled The source nodes have been created using a split catchment approach with the
proposed new roof and driveway areas separated and modelled with stochastic pollutant
generation for each of the surface types as per Table 4.1 - Industrial Split Node Pollutant
Generation Parameters. The area and impervious fractions for each catchment are actual values
based on the design plans.


                        Table 4.1 - Industrial Split Node Pollutant Generation Parameters

  Flow Type         Surface        TSS LOG¹º                         TP LOG¹º VALUES          TN LOG¹º VALUES
                    Type           Mean      St. Dev                 Mean      St. Dev        Mean      St. Dev
  Baseflow          Roof             N/A        N/A                     N/A       N/A           N/A        N/A
                    Driveway         0.78       0.45                   -1.11      0.48          0.14       0.20
                    Ground           0.78       0.45                   -1.11      0.48          0.14       0.20
  Stormflow         Roof             1.30       0.44                   -0.89      0.36          0.25       0.32
                    Driveway         2.43       0.44                   -0.30      0.36          0.25       0.32
                    Ground           1.92       0.44                   -0.59      0.36          0.25       0.32

The proposed treatment train has been modelled as shown in Figure 4.3 - MUSIC Stormwater
Treatment Train. The details of the treatments are described in the following sections




Project number 20210121
File RECOR Preliminary Stormwater Management Report - 20210121.docx, 2021-10-07                                 Page 15 of 26
Revision 0

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