RFI - Appendix D- Stormwater Management Plan · MCU22/0140

Rational Method Calculations

    Project        215101

   Address         7 Ruby Street                                                               By           DK


            Pre - Development                                                                       Post - Development
               Catchment Details                                                                        Catchment Details
     Area             0.1012           ha                                                     Area             0.1012          ha
       fi              0.27                                                                     fi              0.49
     C10           0.75355731                                                                 C10            0.7986166
      I10              70.2          mm/hr                                                     I10              70.2         mm/hr

              Standard Inlet Time                                                                     Standard Inlet Time
     Time               5             mins                                                    Time                4           mins

    Overland Sheet Flow (Friend's Eqn)                                                       Overland Sheet Flow (Friend's Eqn)
    Length                         m                                                         Length                         m
     Slope                         %                                                          Slope                         %

  Surface 'n'                                                                              Surface 'n'

     Time               0             mins                                                    Time                0           mins

           Pipe Flow Travel Time                                                                    Pipe Flow Travel Time
Flow Distance                          m                                                 Flow Distance                         m
Fall of Channel                        m                                                 Fall of Channel                       m
      Time                            mins                                                     Time                           mins

                   Kerb Flow                                                                                Kerb Flow
    Length                             m                                                     Length                            m
     Slope                             %                                                      Slope                            %
     Time              0.0            mins                                                    Time                0.0         mins

    Channel Flow (Figure 4.8 QUDM, or                                                        Channel Flow (Figure 4.8 QUDM, or
          Manning's Equation)                                                                      Manning's Equation)
Flow Distance                          m                                                 Flow Distance                         m
Fall of Channel                        m                                                 Fall of Channel                       m
      Time                            mins                                                     Time                           mins


 Adopted Time of                                                                          Adopted Time of
  Concentration
                        5             mins                                                 Concentration
                                                                                                                  5           mins



      Pre-Development Peak Discharges                                                         Post-Development Peak Discharges
                                                            Design Storm   Frequency
   Area (ha)            Cy          Iy (mm/h)   Qy (m3/s)      (AEP)       Factor (Fy)
                                                                                            Area (ha)             Cy        Iy (mm/h)   Qy (m3/s)

    0.1012         0.60284585         120        0.02        63.20%          0.80            0.1012         0.63889328        120        0.022
    0.1012         0.64052372         150        0.027       39.35%          0.85            0.1012         0.67882411        150        0.029
    0.1012         0.71587945         187        0.038       18.14%          0.95            0.1012         0.75868577        187        0.04
    0.1012         0.75355731         215        0.046        10%            1.00            0.1012          0.7986166        215        0.048
    0.1012         0.79123518         245        0.054         5%            1.05            0.1012         0.83854743        245        0.058
    0.1012         0.86659091         286        0.07          2%            1.15            0.1012         0.91840909        286        0.074
    0.1012         0.90426877         316        0.08          1%            1.20            0.1012         0.95833992        316        0.085

                                                            Discharge Comparison
                      AEP           63.20%       39.35%     18.14%            10%              5%                 2%          1%
                   Difference        0.002        0.002      0.002            0.002           0.004              0.004       0.005
                   Percentage       10.0%         7.4%       5.3%             4.3%            7.4%               5.7%        6.3%