Attachment C - Stormwater report

4.4.3.       Treatment Options
MUSIC modelling has been undertaken to assess the treatment system requirements to achieve the above
water quality objectives. Three treatment systems have been modelled:

    1. Bioretention system
    2. Media filtration system
    3. Infiltration system
4.4.3.1.     Bioretention System
The size of the bioretention system is to be reflective of the total catchment area anticipated for treatment.
Evaluation suggests each basin should be constructed at approximately 2% of the contributing area. It has
been determined a bioretention system will be capable of achieving the load based reduction targets
identified in Section 4.4.2. The parameters utilised to analyse the bioretention system are presented in
Table 9.
Table 9 – Bioretention System Input Parameters

Catchment ID                                                               Bioretention System Parameters
                   2
Surface Area (m )                                                                      454.8

Extended Detention Depth (m)                                                             0.3
               2
Filter Area (m )                                                                       396.8

Saturated Hydraulic Conductivity (mm/hr)                                                200

Filter Depth (m)                                                                         0.5



4.4.3.2.     Media Filtration System
An alternative to a bioretention system is the media filtration system. Runoff is directed to an underground
pit containing filtration media which removes suspended solids and nutrients from the water before
dispersing it into the soil. It has been determined a media filtration system will be capable of achieving a
comparable load based reduction to the same size bioretention system. The parameters utilised to analyse
the media filtration system are presented in Table 10
Table 10 – Media Filtration Input Parameters.

Catchment ID                                                                 Media Filtration Parameters

Extended Detention Depth (m)                                                             0.3
               2
Filter Area (m )                                                                        400

Saturated Hydraulic Conductivity (mm/hr)                                                200

Filter Depth (m)                                                                         0.5




Stormwater Management Plan – Lot 1 on SP108094, 305 Lake Macdonald Drive                                    Page 18

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