RFI - stormwater report

Table 2-2: MUSIC Base and Storm Flow Concentration Parameters – Urban

                                    Total Suspended                  Total
                                                                                    Total Nitrogen
                                         Solids                  Phosphorous
                                                                                     (Log10 mg/L)
  Land Use        Parameter           (Log10 mg/L)               (Log10 mg/L)
                                    Storm      Base            Storm       Base     Storm      Base
                                     Flow      Flow             Flow       Flow      Flow      Flow
                    Mean             2.18       1.0            -0.47      -0.97      0.26      0.20
   Ground
                 Std Deviation        0.39        0.34           0.31     0.31      0.23       0.20
                    Mean              2.43        1.0           -0.30     -0.97     0.26       0.20
    Road
                 Std Deviation        0.39        0.34           0.31     0.31      0.23       0.20
                    Mean              1.30        N/A           -0.89         N/A   0.26       N/A
    Roof
                 Std Deviation        0.39        N/A            0.31         N/A   0.23       N/A
Table 2-3: MUSIC Runoff Generation Parameters – Urban

                                  Parameter                             Urban
                           Rainfall Threshold (mm)                        1
                             Soil Capacity (mm)                          500
                              Initial Storage (%)                        10
                                 Field Capacity                          200
                     Infiltration Capacity Coefficient a                 211
                     Infiltration Capacity Coefficient b                  5
                             Initial Depth (mm)                          50
                             Daily Recharge (%)                          28
                             Daily Drainage (%)                          27
                         Daily Deep Seepage Rate (%)                      0

2.3.2 Catchment Areas
The development site has been divided into three source nodes (road, roof and ground)
representing the areas of the site. The area reporting to the bioretention basin
represents the developable area associated with the subdivision. Table 2-4 outlines the
catchment areas and imperviousness represented within the MUSIC model. The
stormwater quality catchments are provided in Figure 2-1.
Table 2-4: Catchment Areas

             Catchment                Road               Roof           Ground         Total
        Catchment A01 (ha)            0.188              0.250           0.818         1.256
            Impervious %               80                100              25               -




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