Att8 - SWMP

 CONCLUSION
This Stormwater Management Report has outlined how the stormwater run-off from the site is to be managed to
comply with the relevant requirements to minimise any adverse impacts to the downstream environment.

     •    The lawful point of discharge test for the proposed development is achieved as the development continues
          to discharge via the existing flow paths from the site. Assessment of the impacts arising from the
          development have found the relative increase is insignificant and therefore is not likely to impact or cause
          nuisance to the downstream properties.

     •    DRAINS modelling of the catchments under 2100 climate conditions has found that the maximum peak flow
          rate increase resulting from the development is only a 1.6% upon the existing flow rates which is insignificant.
          Attenuation is therefore not considered to be necessary within the development.

     •    As a large rural property with mostly pervious ground areas, the development is not required to achieve the
          stormwater quality objectives of the SPP2017. Notwithstanding, the development will minimise pollutants
          and nutrients from impacting downstream waterways through some key strategies. The majority of roof run-
          off being generated within the development will be captured and stored for reuse and water conservation,
          and the new road surfaces will grade across pervious areas as sheet flow providing a buffering treatment
          and nutrient uptake to improve water quality before it enters the downstream receiving environment.

     •    Review of the Noosa Council flood mapping has found the site is not impacted by storms up to and including
          the 1% AEP storm event, however roads to nearby townships may be cut-off during these storms. A Flood
          Emergency Management Plan shall be prepared for the site to describe a suitable shelter in place strategy
          within the site.

     •    The extension of an existing dam will be used to create an at-grade canoe run. The extension works are to
          be managed to minimise impacts on the local ecosystem and downstream waters at all time during
          construction. Once operational, the existing dam levels and overflows will be unchanged, and no impacts to
          downstream properties are expected as a result of the works.

     •    During construction, erosion and sediment control measures in accordance with best practice standards are
          to be implemented to minimise potential contaminants impacting the downstream receiving environments.
          An erosion and sediment control plan shall be developed as part of a future operational works approval.

     •    The proposed development is able to be effectively managed to ensure that stormwater is captured and
          conveyed through the site, without causing nuisance flows to adjacent or downstream properties, and in
          conjunction with contribution charges towards a future treatment area, the development is able to satisfy the
          Noosa Shire Council requirements for stormwater quality and quantity.




Project number 20220146                                                                                    Page 17 of 20
File RECOR Stormwater Management Plan- 20220146.docx, 2022-09-06 Revision 0

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