1909-13367 SRA referral response approved docs

Table 3 – Critical 1D peak flow rates and critical storms (XPStorm)

                                                      Peak Flow Rate (m3/s)
    AEP Storm Event
                                     Link 59                                  Link 41


            50%                      19.680                                   26.342


      Critical Storm                  3hr_5                                    3hr_9


            20%                      27.492                                   35.661


      Critical Storm                  3hr_5                                    3hr_2


            10%                      34.415                                   39.636


      Critical Storm                45min_1                                    3hr_4


            5%                       38.718                                   45.781


      Critical Storm                  1hr_6                                    3hr_4


            2%                       43.765                                   51.586


      Critical Storm                  1hr_5                                   1.5hr_2


            1%                       44.929                                   56.020


      Critical Storm                45min_6                                    2hr_7


          1 in 500                   51.739                                   64.974


      Critical Storm                 1.5hr_9                                   2hr_1


          1 in 2000                  56.894                                   78.592


      Critical Storm                 1.5hr_5                                   3hr_9


            PMP                      105.000                                  214.520


      Critical Storm                  2hr_8                                    2hr_2




3.1.8 Rat ion al m et h od

The rational method was used as a check against ‘Laurensons’ method to validate the 1D model’s peak
flow results. The Bransby-Williams method and Figures 4.5.4.6 were used to determine the time of
concentration. The table below summarises the time of concentrations for each method.




                                              Flood Study                                       13
S19-007                                122 & 144 Myall St, Cooroy