Updated Stormwater Management Plan · 132007.1841.7

                                Figure 2 – Proposed layout (Actrol/WG Architects)




2.0   Stormwater Runoff

2.1   Existing
      As shown on the existing survey in Appendix A, the site drains to a large chamber located in the
      north-east corner, which then discharges to an existing reserve. Neither the adjacent lots nor the
      road reserve contribute to the site runoff.


      Underground drainage from the common road reserve and adjacent lots pass through the site with
      the road drainage contained within an easement.


2.2   Internal
      The developed site will achieve 90% impermeable site coverage. All roof water and exposed
      pavement runoff will be collected by field inlets and conveyed to detention storage incorporating the
      existing chamber. Attenuated runoff will then discharge to the drainage reserve to the east of the
      site. Pavements and finished ground levels will fall to the rear at grades of 0.5 - 2% as shown on the
      preliminary pavement and stormwater design in Appendix B.


2.3   Detention
      The design AEP for the existing drainage network is unknown, however for the purpose of detention
      design it will be assumed that it has not been designed to cater for full development (Business
      Centre 1 in 10-year as required by SPS6 of the Planning Scheme) of the urban catchment. As the
      site impervious area has increased from 0% to 90%, on-site detention will be assumed to be



                                                                                              Actrol Noosaville
                                                                                                  STP17-0504
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