Engineering Hydrology Plans (IWMP)

Table 7: MUSIC Rainwater Tank Demands

                                      Units     Average             Demand             Daily
      Use           Usage                       Persons             (L/P/D)           Demand
  A-Residential        Toilet           27            1.2             26               842
                   Laundry              27            1.2             35               1,134
 A-Commercial          Toilet           10             2              25               500
    B-Shops            Toilet           3              2              25               150
    C-Tavern           Toilet           1              -               -               1,800
    D-Shops            Toilet           4              2              25               200



Based on the roof catchment areas and the demands estimated for each use, the
rainwater tank modeling parameters are detailed in Table 8.


Table 8: MUSIC Rainwater Tank Parameters

       Parameter                A-Res         A-Comm        B-Shops        C-Tavern    D-Shops
 Total Tank Volume (KL)          30             5             3               60             4
                   2
    Surface Area (m )            10             2             1               25             1
  Overflow Pipe (mm)             90             90            90              90           90
 Annual Demand Scaled
                                  -             -              -             311             -
  by Daily PET (kL/yr)
  Daily Demand (kL/d)           1.98           0.45          0.15            1.80         0.20


2.4.2 Bioretention System




Bioretention systems use ponding above a treatment surface to maximise the
volume of runoff flowing through the filtration media. They typically convey flows
above the design event through overflow pits. The treatment system operates by
firstly filtering surface flows through surface vegetation and then percolating runoff
through prescribed filtration media. This media provides treatment through fine
filtration, extended detention and biological uptake of nutrients. They also provide
flow retardation for smaller events and are particularly efficient in removing
nutrients. These devices can be installed at various scales, from planter boxes in
streetscape to within large detention basins.




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