Att 2 SWMP

     3. Ensuring any stockpiles and construction materials are contained using sediment fencing
        downstream of these areas.

     4. Downstream pits within the property to be protected through filter socks or similar.


     4.2. Operational Phase
The development is to comply with the Noosa Council Water Quality and Drainage Code, AO6.2
which states:

“All stormwater runoff is treated to achieve maximum removal of nutrients, gross pollutants and
suspended solids as determined by cost to efficiency ratios. (e.g., bioretention basins must be sized
to achieve at least 80% reduction in total suspended solids, 60% reduction in total phosphorous, 45%
reduction in total nitrogen and 90% reduction in gross pollutants >5mm).”

It is proposed that the following measures to be implemented will provide the required level of
stormwater quality improvement to minimise impacts to the downstream network:

     •    First-flush divertors will be installed for roof-water drainage to divert initial run-off capture
          to irrigation of the vegetated areas on site.
     •    A 7,500L Slimline Rainwater tanks will be used to capture roof run-off from the proposed
          caretaker building, with 50% of the tank volume allocated to reuse, and 50% to attenuation
          storage.
     •    A 5m² bioretention area will be used to treat and detain stormwater run-off from the newly
          developed area prior to discharge from the site.



          4.2.1 MUSIC Modelling
The proposed development and the above treatment train have been modelled in MUSIC (Model
for Urban Stormwater Improvement Conceptualisation) software in accordance with the Water by
Design MUSIC Guidelines 2018.

The climatic data has been modelled using the rainfall and PET data at station 40059 (Cooroy
Composite) in 6-minute timesteps. The rainfall run-off parameters have been set as defined for the
Southeast Queensland region, shown below in Figure 4.2 - Rainfall run-off parameters for SEQ.




Project number 20210121
File RECOR Preliminary Stormwater Management Report - 20210121.docx, 2021-10-07                                 Page 14 of 26
Revision 0

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