Engineering_Integrated Water Management Plan

Table 8: MUSIC Rainwater Tank Parameters

     Parameter          A1-Res    A1-Comm     A2 -Res   C-Tavern    B-Shops   D-Shops
 Total Tank Volume
                          10          10         20        60          3         3
         (KL)
  Surface Area (m2)        4          4          8         25          1         1
Overflow Pipe (mm)        90          90         90        90         90        90
  Annual Demand
Scaled by Daily PET        -          -          -         311         -         -
       (kL/yr)
Daily Demand (kL/d)      0.44        0.50       1.32       1.80      0.15       0.25


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.
A bioretention system has been proposed to treat the runoff generated from the
Catchment C within the development site. Runoff from the carpark areas are to be
directed to these small bioretention basins, before entering the underground
drainage network. Roadside bioretention systems are also proposed to treat runoff
from the new road to be dedicated to Council. Table 9 summarises the proposed
design parameters for the bioretention basin for this development. Indicative
bioretention locations are highlighted in Figure 6.




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