8. APP G. Engineering RFI Response

                INTERNAL CATCHMENT ASSESSMENT
                TEMPORAL PATTERNS
                Rainfall data and information from the Australian Bureau of Meteorology was utilised to
                generate the design storm event hydrographs for the stormwater run-off. Intensity-Frequency-
                Distribution (IFD) charts and tables for the specific subject site are presented in Appendix D.


                LEGAL POINT OF DISCHARGE
                The subject site currently contains three internal catchments which discharge flows into three
                separate locations.

                      - At the southern border of the site, there is a 600mmx600mm field inlet pit, which collects
                        flows and discharges to a 300mm diameter stormwater pipe within the Lionel Donovan
                        Drive road reserve.

                      - There are two field inlets located within the kerb and channel along Eumundi Noosa
                        Road, which collect flows from Lot 4SP159610. These pits discharge into a 675mm
                        diameter pipe within the Eumundi Noosa Road road reserve. These pipes flow to the
                        north toward Lake Doonella and the Noosa River.

                      - There is also a 225mm diameter pipe within the existing drainage easement of Lot
                        31SP170751. This then increases to a 300mm diameter stormwater pipe in the adjacent
                        lot to the east. At the junction of these pipes is a 600mmx900mm field inlet, which collects
                        overland flow from Lot 31SP10751.

                The internal catchments are illustrated in the engineering drawings in Appendix B.


                CATCHMENTS
                The site has three internal catchments. Details of these catchments are provided in Hyder
                Drawings SK01300-AA007595-01.


                CATCHMENT 1 DISCHARGE
                Catchment 1 is a small internal catchment at the south of Lot 4 on SP159610. In its existing
                state, the catchment area is used for commercial and automative purposes.
                Table 4.1, below, lists the catchment characteristics for the site.
                                               Table 4.1 – Peak discharge flow rates comparison

                           PARAMETERS                                    EXISTING                   DEVELOPED

                     Approx. Developed Area                                  0.10                         0.09

                         Fraction Impervious                                 0.85                         0.85

                    Coefficient of Runoff (C10)                              0.87                         0.87

                    Coefficient of Runoff (C50)                                1                           1

                       Time of Concentration                             5 minutes                    5 minutes

139 Eumundi Noosa Road & 30 Lionel Donovan Drive, Noosaville Service Station and Retail Site—Stormwater
Management Plans
Hyder Consulting Pty Ltd-ABN 76 104 485 289                                                                       5
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