Response to Information Request - MCU12/0184

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                                                                                 Callaghan & Toth

3.       WATER QUALITY MANAGEMENT PLAN

3.1      Proposed On-Site Stormwater Treatment Process

The developed site was divided into MUSIC model sub-catchments as shown on Plans 02 to
05. The proposed treatment train for the development site is illustrated on Plans 02 to 05
and listed below:


1. The Bioretention Swale will treat the stormwater runoff from the access roads, car parks,
     from Catchment F. The Swale is 0.6m wide at the base and will be vegetated with
     effective nutrient removal plants. The treated runoff will then be directed to vegetated
     areas within the       property which eventually drain to dams which use the collected water
     for irrigation of the Avocado trees. The bio-retention component will remove the
     nutrients, heavy metals, and retard flow.

2.   Grass Swales will treat the stormwater runoff from grassed areas adjacent sheds,
     Catchments C, G, GA, H, T, U and W. The Swales will be 0.6m wide at the base and will
     not be vegetated with effective nutrient removal plants.


3. The Bioretention Basin will treat the stormwater runoff from access roads, carparks from
     Catchment K and N. The Bioretention Basin will be 55m2 in area and will be vegetated
     with effective nutrient removal plants. The treated runoff will then be directed to
     vegetated areas within the property. The bio-retention component will remove the
     nutrients, heavy metals, and retard flow.

4. Grass Vegetated Buffers will treat the stormwater runoff from access roads and carparks
     from Catchments A, B, 0, E, I, L, M, 0, P, Q, R, S, V, W1 and X. The vegetated Buffers
     will be 5m wide for the length of each catchment and flow from the catchments will be via
     sheet flow.


5.   Rainwater Tanks will be required to collect water from the new roofs. The tanks are to be
     above ground with an overflow pipe discharging to the adjacent swales which drain to on
     site dams used for irrigation. The tank capacity is to be adequate for the part supply of
     chicken water needs and to control humidity in the sheds.




3.2      MUSIC Model

3.2.1 Source Nodes


Catchment areas of source nodes within the proposed development have been identified as
sub-catchments such as roofs, carparks, roads and verge areas. MUSIC allows for the
characteristics of these source nodes to be amended to ensure that accurate pollution
generation and hydraulic characteristics are used to generate stormwater runoff within the
model. Table 3.1 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 site has been related to a "Commercial" land use and pollutant export
parameters detailed in the Guidelines for this land use have been used for each node.
Figure 3.1 shows the MUSIC model.



                                                                                              12
1209 Animal Husbandry   Top Forestry Rd, Ridgewood
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                                                                                     SWQMP
April 2013