8. APP G. Engineering RFI Response

         A comparison of the parameters listed in Table 4.1 demonstrates that the proposed
         development will not increase the rate of stormwater runoff discharged from the site as the
         proposed development does not change the existing impervious area and stormwater runoff
         volumes. Therefore, no onsite detention is required to mitigate peak discharge flow rates.
         Stormwater runoff from the proposed development site can be discharged directly to the lawful
         point of discharge, which for Catchment 1 is Lionel Donovan Drive.


         CATCHMENT 2 DISCHARGE
         Catchment 2 is an internal catchment on Lot 4 on SP159610. In its existing state, the catchment
         area is used for retail and automative purposes.
         Table 4.2, below, lists the catchment characteristics for the site.
                                Table 4.2 – Peak discharge flow rates comparision

                 PARAMETERS                              EXISTING                                DEVELOPED

            Approx. Developed Area                           0.26                                      0.24

               Fraction Impervious                             1                                        0.9

            Coefficient of Runoff (C10)                       0.9                                      0.88

            Coefficient of Runoff (C50)                       1.0                                       1.0

              Time of Concentration                       5 minutes                                 5 minutes


         A comparison of the parameters listed in Table 4.2, above, demonstrates that the proposed
         development will not increase the rate of stormwater runoff discharged from the site as the
         proposed development does not change the existing impervious area and stormwater runoff
         volumes. Therefore, no onsite detention is required to mitigate peak discharge flow rates.
         Stormwater runoff from the proposed development site can be discharged directly to the lawful
         point of discharge, which for Catchment 2 is Eumundi Noosa Road.


         CATCHMENT 3 DISCHARGE
         Catchment 3 is an internal catchment that covers all of Lot 31SP170751. In its existing state, the
         site is undeveloped.

         CATCHMENT PARAMETERS
         A summary of the catchment parameters is presented in Table 4.3.

         Table 4.3: Summary of Catchment Areas
                 PARAMETERS                              EXISTING                                DEVELOPED

            Approx. Developed Area                           0.42                                      0.47

               Fraction Impervious                            0.1                                      0.90

            Coefficient of Runoff (C10)                      0.72                                      0.89

            Coefficient of Runoff (C50)                      0.83                                      1.00

              Time of Concentration                    17.7 minutes                                 5 minutes


                                                                                            Stormwater Management Plans
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