Attachment E - Stormwater Management Report · MCU24/0112

       •    ≥ 60 % reduction in total phosphorus load (TP)

       •    ≥ 45 % reduction in total nitrogen load (TN)

       •    ≥ 90 % reduction in gross pollutant load
Pollutants typically generated during the operational phase of the development include:

       •    Litter/gross pollutants;

       •    Sediment;
       •    Nutrients (N & P);

       •    Hydrocarbons (oils and grease); and

       •    Heavy metals.

Stormwater treatment measures are shown on the attached stormwater management drawings and
include:
       •    ATLAN FIL.30-EMC-M Filter system to be installed within the proposed combined treatment
            tank within development site for final treatment of stormwater prior to discharging to the
            stormwater network.
Stormwater modelling has been carried out using MUSIC modelling software to determine the required
infrastructure needed to meet the Water Quality Objectives (WQO’s) above.

4. 2       MU S IC M od el

MUSIC modelling for this development has been carried out using MUSIC Version 6.4 and rainfall data
obtained from the pluviograph tool on the eWATER website for Cooroy Composite. The developed site
catchment and treatment measure details included in the MUSIC model are outlined in Table 1.

Table 1 – MUSIC model parameters

                        Description                                    Specification

 Assumed road catchment to filter system                       0.0368 Ha (100% impervious)

 Assumed roof catchment to filter system                       0.1084 Ha (100% impervious)

 Assumed ground catchment to filter system                      0.1140 Ha (30% impervious)

 Assumed ground catchment bypassing filter                      0.0066 Ha (19% impervious)
 system

 Assumed road catchment bypassing filter                       0.0008 Ha (100% impervious)
 system

 Assumed access path bypassing filter system                   0.0058 Ha (100% impervious)
 and discharging from site via swale drain

 Number of modelled ATLAN Filters                                            8

The MUSIC model layout is shown in Figure 2.




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