16-04-21 - 15128 - MorgansEngineers

                                                                         MORGAN CONSULTING
                                                                         E NGINEERS P TY LTD
                                                                                     15128/RP



                designed to cater for ultimate development of Precinct E2. Additionally, the
                Lake system within the Noosa Springs Golf Course incorporates on-site
                detention to mitigate flows prior to discharging to Lake Weyba. The above has
                been documented in the Noosa Springs Master Drainage Report prepared by
                Ralph M. Grierson. Additionally, a capacity analysis of the existing
                downstream piped system was provided in the Engineering Services Assessment
                – Revision 1 prepared by Morgan Consulting Engineers. The report
                demonstrates that the existing infrastructure has capacity to cater for the
                fully developed site. The above has been confirmed with Cherie O’Sullivan of
                Noosa Council as part of the Precinct F Development Assessment.

  B)            That the development will not adversely impact on the existing drainage
                conditions on other properties (including road reserves and public roads) or on
                the environment (E.g. causing erosion and sediment movement).

Response:       Refer to Response to 9.A.

Water Quality
Issue – Lawful Discharge
Item 10:        Demonstrate proposed water discharges will occur lawfully and the nature and
                extent of easements required.
Response:       Refer to Response to 9.A. Furthermore, an internal gravity drainage system
                will be constructed to cater for minor storm events whilst the internal road
                network will be designed to cater for the major storm events.

Issue – Velocities and Residence Times

Item 11:        Demonstrate how predevelopment ARI velocities will be maintained to ensure
                waterway stability pursuant to the State Planning Policy and how water flows
                will be managed to adequately manage residence times within the lake system.

Response:       As documented in the Noosa Springs Master Drainage Report prepared by Ralph
                M. Grierson, the Noosa Springs lake system incorporates on-site detention to
                maintain pre-development peak flow rates prior to discharging into Lake
                Weyba. The system has been designed to mitigate flows from the fully
                developed contributing catchment which includes Precinct E2 for storm events
                which include the 1 year ARI event.

                The stormwater quality treatment options for Precinct E2 are currently being
                assessed in parallel with Precinct F with consideration given to the existing
                lake system. We request that a Site Based Stormwater Quality Management
                Plan for Precinct E2 be conditioned as part of the development approval.

Issue – Stormwater Treatment

Item 12:        Demonstrate how nutrients within stormwater runoff will be managed to
                ensure that the proposed development will not be responsible for nutrient
                related problems within the lake system and to meet relevant stormwater
                quality treatment codes and policies. Provide a Management Plan for approval
                for any proposed measures.



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