5179IWMP_Rev3

                                                                               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 – Lot 12 plus road reserve;
   • Catchment B – Existing lots and Lots 8, 9 & new lots 7, 10, & 11 plus road reserve;
   • Catchment C – Lots 5 & 6 plus road reserve;
   • Catchment D – Lot 4 plus road reserve;
   • Catchment E – Lots 2 & 3 plus road reserve;
   • Catchment G – Lot 15 and a portion of lot 14; and
   • Catchment H – Lot 13 and a portion of lot 14 plus road reserve.

It is noted that Catchment F (lot 1 and part of the road) flows to Erindale Park Stage 4 and was
included in the treatment capacity of the Biobasin within Erindale Park Stage 4.

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

    •    One Bioretention Basin (BB4).
    •    Four roadside Biopods (BB1, BB2, BB3, and BB5).

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 from the mapped waterway into the adjoining park area
(Lot 99 RP881300) which then outlets into the tributary of Six Mile Creek to the north-east of the
lots.




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2035 2 Pearsons Road IWMP – Revision 3                                         April 2021