Att 2 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 and minimise any adverse impacts to the
downstream catchments.

     •    The existing site surface run-off is captured internally and discharge into the Council
          stormwater infrastructure on Rene St and within the easement on the property.

     •    The proposed legal point of discharge for the newly developed area of the site will be the
          stormwater network within the easement on the property.

     •    The existing and proposed development site have been modelled for the critical design
          storm events for the site, which found attenuation would be required. Provision of a 7.5kL
          rainwater attenuation tank with 3.75kL of attenuation storage was found to provide suitable
          mitigation to the development to ensure that there will be no increase to existing peak flow
          discharges from the site for any of the storm events.

     •    During construction, erosion and sediment control measures are to be implemented to
          minimise potential contaminants impacting the downstream receiving environment. An
          erosion and sediment control plan shall be developed as part of a submission for Operational
          Works approvals.

     •    In the operational phase of the development, a stormwater treatment train will provide
          quality improvements as required by the Noosa Council Planning Scheme Policy. Roof run-
          off from the new caretaker’s facility will be captured in a 7,500L rainwater reuse and
          attenuation tanks. The tank is to be plumbed for reuse in internal toilets, serving to provide
          both treatment and reduce the volume of run-off leaving the site. Overflows from the tanks,
          as well as the surface run-off from the driveway will be directed toward a 5m2 bioretention
          areas providing the required treatment for the proposed development. Outflows from the
          bioretention area will be discharged through the stormwater infrastructure in the drainage
          easement within the property

          By implementing the proposed stormwater treatments, the development will reduce the
          quantity of stormwater pollutants by more than 90% of gross pollutants, 80% of total
          suspended solids, 60% total phosphorous and 45% total nitrogen, exceeding the pollutant
          reduction targets required for the site.

     •    The proposed stormwater solution is considered to minimise any adverse impacts to the
          downstream environment arising from the stormwater run-off while also meeting the
          stormwater quality targets required for the development.




Project number 20210121
File RECOR Preliminary Stormwater Management Report - 20210121.docx, 2021-10-07                                 Page 20 of 26
Revision 0

P +61 7 5211 1003                A 37 Mary St, Noosaville Qld 4566                E [email protected]   recorconsulting.com