RFI (rec. 5.06.26) 2567 - Appendix B - Site-Based Stormwater Management Plan (SBSMP) (Ver. 2)

6.0 CONCLUSION

This stormwater management plan has assessed the proposed development with respect to
both stormwater quality and quantity. The catchment hydrology has been assessed to
ensure the development will not cause actionable nuisance, flooding, or degradation of
runoff quality, and that outcomes are consistent with the requirements of the Noosa Shire
Council Planning Scheme.


Based on this assessment, the following conclusions are made:


        A bioretention device with a total of 210m² of filter media is required to achieve
         water quality treatment targets. This basin is to be constructed as part of Stage 1 and
         is designed to treat runoff from the entire site catchment.
        Hydrological modelling was undertaken in WBNM across a full range of design storm
         events, supported by Rational Method verification.
        The drainage strategy directs the majority of runoff to the southeast discharge point.
         This is consistent with the previous approval for this site.
        Increased post-development flows to LPOD1 are attenuated through a 472m³
         detention basin, ensuring the overall discharge from the site does not exceed pre-
         development levels. The detention basin is co- located within the detention basin and
         is designed to cater for the post-developed flows for the entire development. This will
         be delivered in Stage 1.
        With interim staging, the full undeveloped upstream catchment, with the exception of
         the small catchment naturally draining to Taylor Court, can be conveyed by piped
         drainage to the ultimate basin. Temporary diversion drains and field inlet pits are
         provided to maximise catchment diversion to the basin with each successive stage, as
         shown on proposed civil design drawings.
        Council mapping has confirmed that the site is not subject to flood encumbrance.


In conclusion, while the peak flow rates and distribution of flows are altered, the overall post-
development discharges are managed such that they do not worsen existing conditions. The
proposed stormwater management system achieves compliance with Noosa Shire Council
requirements, meets water quality treatment targets, and ensures all stormwater is
discharged lawfully in accordance with QUDM (2016).




2576-SBSMP-01_Version 2.0 (April 2026)                                               Page 22 of 23
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