Further Advice Letter Response_FINAL

                                                                 Rational Method Peak Flow Calculations
Job No:            17155
Job Type:          Proposed Residential Development
Address:           Precinct E2 Noosa Springs, Noosah
Council:           Noosa Council



IFD Data:          26.8625 (S),152.9625 (E)                                Minor Storm:   Q10                                                                                  Designed:      WB
1
I10                71mm/hr                                                 Major Storm:   Q100                                                                                  Checked:      HM

Pre Development                                                                                         Post Development

Time of Concentration

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

Sheet Flow (Friends Equation)                                                                           Sheet Flow (Friends Equation)
     Sheet flow length (L)                          m                                                         Sheet flow length (L)                    m
            roughness (n)                                  short grass                                               roughness (n)                           short grass
               Fall of NSL                         m                                                                    Fall of NSL                   m
     Slope of Surface (S)                          %                                                           Slope of Surface (S)                   %
                       total                0.0   mins                                                                          total         0.0    mins
Concentrated Overland Flow                                                                              Concentrated Overland Flow
           Flow distance                           m                                                                Flow distance                     m
                 velocity                   1.5   m/s                                                                     velocity            1.5    m/s
                    mins                    0.0   mins                                                                       mins             0.0    mins
   Surface type multiplier                  3.0                                                             Surface type multiplier           3.0
                     total                  0.0   mins                                                                        total           0.0    mins

Total tc                                    5.0   mins                                                                   Total tc             5.0    mins



Runoff Volume Calculations


      Name          Area (ha)         tc             fi      C10                                            Name          Area (ha)      tc             fi    C10
                     0.092                         0.57      0.81                                                          0.092                      0.61    0.82

           Total      0.092          5.0                     0.81                                                Total      0.092       5.0                   0.82

                   Frequency                                                                                             Frequency
      ARI                             Cy            Iy                     Qy                                ARI                         Cy            Iy                    Qy
                     Factor                                A (Ha)                                                          Factor                           A (Ha)
    (years)                        (Fy*C10)       (mm/h)                 (m3/s)                            (years)                    (Fy*C10)       (mm/h)                (m3/s)
                      (Fy)                                                                                                  (Fy)
      3 mth                                                              0.010                              3 mth                                                          0.010
         1            0.800         0.651          124      0.092        0.021                                 1            0.800      0.658          124    0.092         0.021
         2            0.850         0.691          139      0.092        0.025                                 2            0.850      0.699          139    0.092         0.025
         5            0.950         0.773          186      0.092        0.037                                 5            0.950      0.781          186    0.092         0.037
        10            1.000         0.813          219      0.092        0.045                                10            1.000      0.822          219    0.092         0.046
        20            1.050         0.854          251      0.092        0.055                                20            1.050      0.863          251    0.092         0.055
        50            1.150         0.935          295      0.092        0.070                                50            1.150      0.945          295    0.092         0.071
       100            1.200         0.976          329      0.092        0.082                               100            1.200      0.987          329    0.092         0.083




                                                                                          Page 1 of 1                                                                                      9/02/2022