Reference Documents - Stormwater Management Plan & Waste Management Plan - MCU26/0040, OPW26/0066 & RAL26/0013 (As Published)

               Rational Method Calculations
                                                                    Cooroy
                  Job Number            2576         IFD         ANY LOCATION           NEW IFD

                    Address        mfr-cmp                                      By         CL


               Pit 1/1                                                               Pit 1/2

Ref 1          Catchment Details                                                     Catchment Details
                      Area             1.8403        ha                                    Area            1.8403            ha
                        fi              0.00                                                 fi             0.86
                      C10                0.7                                               C10              0.872
                       I10              84.24       mm/hr                                   I10             84.24          mm/hr


Ref 2          Standard Inlet Time                                                   Standard Inlet Time
                     Time                0          mins                                   Time               5             mins


Ref 3          Overland Sheet Flow (Friend's Eqn)                                    Overland Sheet Flow (Friend's Eqn)
                    Length             240           m                                    Length             20              m
                     Slope            1.32           %                                     Slope              2              %

                   Surface 'n'        av. grass     0.045                               Surface 'n'        paved           0.015

                     Time              28.31        mins                                   Time             3.79            mins

Ref 4          Pipe Flow Travel Time                                                 Pipe Flow Travel Time
                 Flow Distance           0           m                                 Flow Distance       200               m
                     Avg. Dia            0          mm                                     Avg. Dia        450              mm
                 Fall of Channel         1           m                                 Fall of Channel      1                m
                       Time              0          mins                                     Time          1.52             mins

               Kerb Flow                                                             Kerb Flow
                     Length              0           m                                    Length              0              m
                      Slope              1           %                                     Slope              1              %
                      Time              0.0         mins                                    Time             0.0            mins


Ref 4              Channel Flow (Figure 4.8 QUDM, or                                  Channel Flow (Figure 4.8 QUDM, or Manning's
                           Manning's Equation)                                                          Equation)
                Flow Distance                     m                                    Flow Distance                      m
                Fall of Channel                   m                                   Fall of Channel                     m
                      Time                      mins                                        Time                         mins


                    Time of                                                               Time of
                                        28.3        mins                                                    10.3            mins
                 Concentration                                                         Concentration



               Peak Discharge Calculations

               Pit 1/1                                                               Pit 1/2

Design
                                     Frequency
Storm              Area (ha)                         Cy       Iy (mm/h) Qy (m3/s)        Area (ha)           Cy           Iy (mm/h)   Qy (m3/s)
                                     Factor (Fy)
(AEP)
 63%       1      1.84029982            0.80         0.56        73         0.209       1.84029982         0.6976           116        0.414
 39%       2      1.84029982            0.85        0.595        91         0.277       1.84029982         0.7412           145        0.549
 18%       5      1.84029982            0.95        0.665        113        0.384       1.84029982         0.8284           179        0.758
 10%      10      1.84029982            1.00         0.7         130        0.465       1.84029982          0.872           205        0.914
  5%      20      1.84029982            1.05        0.735        147        0.552       1.84029982         0.9156           233        1.091
 2%       50      1.84029982            1.15        0.805        171        0.704       1.84029982            1             268         1.37
 1%      100      1.84029982            1.20        0.84         188        0.807       1.84029982            1             294        1.503

Ref 5          Advice on Selection of AEP design events for various scenarios