5179SQMP_2 PearsonsRd_Feb2021_Rev2_

                                                                                Callaghan & Toth


4.0 WATER QUALITY MANAGEMENT PLAN
4.1      Proposed On-Site Stormwater Treatment Process

The developed site was divided into MUSIC model sub-catchments as follows:
    Catchment A – Lots 11 to 12 plus road reserve,
    Catchment B – Existing lots and Lots 8, 9 & 18,
    Catchment C – Lots 13 to 14 plus road reserve,
    Catchment D – Lots 15 to 17,
    Catchment E – Lots 1 to 5 plus road reserve, and
    Catchment F – Lots 6, 7, part of 9 & 10.

The proposed stormwater treatment train for the overall development site is:

        One Bioretention Basin (BB4) incorporated into a detention basin.
        Three roadside Biopods (BB1 to BB3).
        Three Tree Pits (TP1 to TP3).

BioBasin 4 is located within the new Parkland Area and discharges into the tributary to the east
of the site.

The bio-retention component of the treatment systems will remove the nutrients, heavy metals,
and retard flow.


4.2      MUSIC Model
4.2.1 Source Nodes

Catchment areas of source nodes within the proposed development have been identified as
sub-catchments such as roofs, yard, road and verge. See Figure 4.1 showing the MUSIC
model layout for this proposal.

MUSIC allows for characteristics of these source nodes to be amended to ensure that accurate
pollution generation and hydraulic characteristics for each sub-catchment are used to generate
stormwater runoff within the model. Table 4.1 below details the sub-catchments used in the
MUSIC model, land use, percent imperviousness and area of each sub-catchment. The MUSIC
Modelling Guidelines for South-East Queensland – Version 1 December 2010 have been used
to set level of imperviousness. The urban residential pollutant export parameters within the
guidelines have been used for each node.

The site has one main discharge point into the proposed biobasin / detention basin system,
which then outlets into the tributary of Six Mile Creek to the east of the lots.




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2035 2 Pearsons Road IWMP – Revision 2                                       February 2021