18164 - SBSMP - Rev 0

                                                                                          18164 - SBSMP/0
                                                                                                       Page 12




    2. First flush roofwater runoff from the proposed hotel building will be collected by the
       internal drainage network and directed to the proposed bio-retention basin for treatment.
       Roofwater runoff exceeding first flush will bypass treatment.
    3. Surface runoff from the proposed residential properties and road surface will be collected
       by the internal drainage network and directed to the proposed bio-retention basin for
       treatment.
    4. Surface runoff from the proposed hotel development will bypass treatment.

All runoff described above will then discharge to the lawful point of discharge. Siteworks and
Drainage Plans of the proposed internal drainage network detailing the treatment train assets are
included in Appendix D. Refer to Table 6.5 for details of the proposed treatment train assets.

                                 Table 6.5 - Proposed Treatment Assets

          Treatment          Treatment
                                                                      Description
            Level              Asset

          Primary/                                1. 130m2 Total Filter Media Area
         Secondary/      Bio-retention Basin      2. 0.4m Filter Media Depth
          Tertiary                                3. 0.2m Extended Detention Depth


          Primary/                                1. 20 x 3kL tanks installed within the residential
                          Rainwater Reuse
         Secondary/                                  detached dwelling allotments.
                               Tanks
          Tertiary                                2. 200kL tank installed within hotel allotment.


Refer to Appendix E for the Bio-retention Operational Management and Maintenance Guidelines
and for Appendix F the Bio-retention Basin Design Checklist and Calculations.

6.3.3 Pollutant Export Modelling
Following the definition of water quality objectives for the site and an assessment of the treatment
options suitable for the development, the most appropriate treatment scheme for the site was
identified. The impact of the stormwater management strategy on the quality of stormwater runoff
discharged from the site has been assessed using the pollutant export model, Model for Urban
Stormwater Improvement Conceptualisation (MUSIC).

6.3.4 MUSIC Modelling Parameters
The MUSIC model was set up in accordance with the Water-By-Design MUSIC Modelling Guidelines
for South East Queensland to the parameters listed in Table 6.6. Refer to Figure 6.1 for source
node areas.

                                           Table 6.6 – MUSIC Parameters

                       Parameter                               Data Used

                                                  Cooroy Composite 40496 (north),
                      Rainfall Data
                                               SUNSHINE COAST REGIONAL 1973 to 1983
                   Modelling Timestep                          6 minutes

                         Routing                  No routing drain links were adopted



Site Based Stormwater Management Plan
Reconfiguration of a Lot and Mixed Use Development at 215 David Low Way, Peregian Beach