RFI - Stormwater management (flood report)

      Table 3-2: Urban land use (Split Source Nodes) - Pollutant Export Parameters

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


      Table 3-3: MUSIC Runoff Generation Parameters

                              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

      3.2.3. Catchment Areas

      The development site and external catchment has been split into three catchments
      containing split source nodes (road, roof and ground) representing total developed area
      reporting to the bioretention basin. Table 3-4 outlines the catchment areas and
      imperviousness represented within the MUSIC model. The stormwater quality catchments are
      provided in Figure 3-1.
      Table 3-4: Catchment Areas

       Catchment                       Total Area         Road (ha)     Roof (ha)      Ground
                                          (ha)                                          (ha) /
       Site                               1.384             0.342           0.250          0.791
       External                           0.464               -             0.049          0.415
       Imperviousness (%)                                    60             100             15




21-0166SMP01-V1 | Stormwater Management Plan | 25 Pavilion Street, Pomona                                           | 15