C2. Eng Report

                                                    Proposed Service Station – 175 Eumundi Noosa Road, Noosaville
                                                                                 Ref: 20769 C R001 Rev 06 09.02.17
                                                                                                    February 2018


                                   Table 2- Pre-development Catchment Details
                                                                         Time of
           Catchment       Area           %                                                 Q10         Q100
                                                      C10      C100    Concentration
               I.D         (m2)       Impervious                                           (m3/s)      (m3/s)
                                                                           (tc)

               EX1         0.197          95%         0.89     1.00           5.0           0.109       0.176


8.5      Post-Development Hydrology
         The total land area considered for the post-development was 1,972 m2. A catchment plan for the
         post-developed site was determined based on preliminary architectural drawings. The post-
         development catchment plan is attached within Appendix C for further information.

         Based on preliminary architectural drawings, the area and fraction impervious of the various
         catchment and sub-catchments were determined. The Coefficient of discharge (C10) value for the
         site was derived from QUDM 2013 Table 4.5.3 and Table 4.5.4. Fy frequency factors were applied to
         determine runoff coefficients for various average recurrence interval (ARI) storm events in
         accordance with QUDM 2013 Table 4.5.2.

         Similar to Section 8.4, QUDM 2013 Section 4.6 was applied to determine the total times of
         concentration (Tc) of 5.0 minutes for catchment C1. Rational Method calculations were performed,
         the results of which can be seen in Table 3

                                   Table 3 - Post-development Catchment Details
                                                                         Time of
           Catchment       Area           %                                                 Q10         Q100
                                                      C10      C100    Concentration
               I.D         (m2)       Impervious                                           (m3/s)      (m3/s)
                                                                           (tc)

               C1          0.197          85%         0.79     1.00           5.0           0.106       0.176


8.6      Detention Analysis and Strategy
         ADG recommends no inclusion of on-site detention measures due to no net increase in post-
         development peak flow.

8.7      Lifecycle Costs
         A lifecycle cost analysis is not a part of the scope of this report. All stormwater infrastructure
         associated with the development shall be maintained and serviced by the owners of the development
         at their own cost.




BRISBANE / SYDNEY / MELBOURNE / GOLD COAST / SUNSHINE COAST / DARWIN / PERTH                              Page 17