Att 2 SWMP

Rational Method Calculations
Project number:                            20210121                                                                            Calculations:                             B. Parry
Street Address                             16 Rene St                                                                          Date:                                     7/10/2021
Locality:                                  Noosaville, Noosa Shire Council




Validation of Pre-Development Model                                                                                            Pre / Post Comparison
A.E.P                                      Q (m3/s) - WBNM                 Q (m3/s) - Rational           Differential          A.E.P                                     Qy Pre (m3/s)           Qy Post (m3/s)           Qchange (m3/s)    Qchange (%)
                               63.2% AEP                           0.031                         0.031                    0%                                 63.2% AEP                   0.031                    0.034             0.003                 10%
                                50% AEP                            0.038                         0.037                   -3%                                  50% AEP                    0.038                    0.040             0.002                  5%
                                20% AEP                            0.062                         0.057                   -8%                                  20% AEP                    0.062                    0.065             0.003                  5%
                                10% AEP                            0.077                         0.070                   -9%                                  10% AEP                    0.077                    0.082             0.005                  6%
                                  5% AEP                           0.093                         0.084                  -10%                                    5% AEP                   0.093                    0.094             0.001                  1%
                                  2% AEP                           0.106                         0.107                    1%                                    2% AEP                   0.106                    0.108             0.002                  2%
                                  1% AEP                           0.116                         0.124                    7%                                    1% AEP                   0.116                    0.121             0.005                  4%




Validation of Post-Development Model                                                                                           Pre / Post (OSD) Comparison
A.E.P                                      Q (m3/s) - WBNM                 Q (m3/s) - Rational           Differential          A.E.P                                     Qy Pre (m3/s)           Qy OSD (m3/s)            Qchange (m3/s)    Qchange (%)
                               63.2% AEP                           0.034                         0.033                   -3%                                 63.2% AEP                   0.031                    0.030            -0.001                 -3%
                                50% AEP                            0.040                         0.039                   -3%                                  50% AEP                    0.038                    0.036            -0.002                 -5%
                                20% AEP                            0.065                         0.060                   -8%                                  20% AEP                    0.062                    0.059            -0.003                 -5%
                                10% AEP                            0.082                         0.074                  -10%                                  10% AEP                    0.077                    0.074            -0.003                 -4%
                                  5% AEP                           0.094                         0.089                   -5%                                    5% AEP                   0.093                    0.085            -0.008                 -9%
                                  2% AEP                           0.108                         0.113                    5%                                    2% AEP                   0.106                    0.099            -0.007                 -7%
                                  1% AEP                           0.121                         0.130                    7%                                    1% AEP                   0.116                    0.107            -0.009                 -8%