RFI - Stormwater Mgm Plan 20169 - SBSMP - Rev 4 (2)

                                                                                     20169 - SBSMP/4
                                                                                               Page 18




6.3.2 Proposed Treatment Train
The proposed treatment train has been modelled using the following methodology:

    1. Roofwater from Building 1 will be collected by a 15kL rainwater reuse tank with overflow to
       the Eumundi Noosa Road kerb and channel. The rainwater tank will be utilised for landscape
       irrigation only, servicing all common landscape areas and the private courtyards of Block 5.

    2. Roofwater from the rest of the proposed development will be collected by the internal
       drainage network which will subsequently direct flow to the end-of-line bio-retention basins
       for treatment.

    3. Surface runoff from the hardstand areas and landscaping areas will be collected by various
       pits. The internal drainage networks will subsequently direct flow to the end-of-line bio-
       retention basins for treatment.

All runoff described above will then discharge to the lawful points of discharge. A Concept Site
Levels and Drainage Plan of the proposed internal drainage network detailing the treatment train
assets is included in Appendix F. Refer to Table 6.5 for details of the proposed treatment train
assets.

                                Table 6.5- Proposed Treatment Assets

          Treatment          Treatment
                                                                     Description
            Level              Asset

                          Rainwater Reuse          15kL tank installed at the north western
           Primary/
                          Tank (Landscape          corner of the site, irrigating an area of
          Secondary
                           Irrigation Only)        1,570m2.


                                                  1. 40m2 Total Filter Area
                            Bio-retention
                                                  2. 0.4m Filter Media Depth
                               Basin A
          Primary/                                3. 0.2m Extended Detention Depth
         Secondary/
          Tertiary                                1. 55m2 Total Filter Area
                            Bio-retention
                                                  2. 0.4m Filter Media Depth
                               Basin B
                                                  3. 0.2m Extended Detention Depth


Refer to Appendix K for the Stormwater Quality Operation Management and Maintenance
Guidelines.

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).




Site Based Stormwater Management Plan
Proposed Townhouse Development at 99, 101 & 105 Eumundi Noosa Road, Noosaville