Development Application part 2 of 2 Report and Plans MCU13/0030

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                                                                                          Callaghan & Toth

4.2.2 Treatment Nodes


The "MUSIC Modelling Guidelines for South East Queensland" Version 1 prepared by Water by
Design and dated December 2010 has been used to set the rainfall runoff parameters and
pollutant export parameters for the site.

The land use type used for this model was "Commercial" and the values in the guideline shown
in Table 3.7 and Table 3.8 of the guidelines have been used in this model.


Rainwater Tanks have been provided for the roof catchment as shown on Plan No 1303-02.
The Reuse allowed is for:


1.       A daily re-use of 40L/person/day toilet + laundry (23Tx1px40 = 920 L/day)


2.        1500L/day ([1 030m2xO.53m     = 546 KL/yr] + 364   1,500 L/day) for landscaping as per
                                                               =



         the "Water by Design   -
                                    Music Modelling Guidelines". Two (2)tanks are provided with a
         total of 46,000 litres on site. The overflow from the rainwater tanks flows to the bio-
          retention basin that drains to the southern vegetated area within the site.


Bio retention Swale is adjacent the carpark in catchment B2 and will treat runoff from this
catchment and rainwater tank overflows. The bioretention swale is 1 m wide at the base, 2.6m
wide overall and 30m long. It has a 1 % grade flowing into the Bioretention Basin. The size of
this system has been designed in accordance with Plan 1303-03.


Bioretention Basin has been placed close to the edge of car parks to treat runoff from
Catchments B1, B2 and rainwater tank overflows. One (1)bio-retention basin has been used,
with an area of 36m2. It has a filter layer depth of 0.3m and an extended detention depth of
0.6m. The size and depth of the system has been designed in accordance with Plan 1303-03.
The bio-retention basin drains to vegetated area within the site.


4.2.3     Rainfall Data


The meteorological data used for the MUSIC Model was the data for Cooroy from 01/01/92-
31/12/01.


The mean Annual Rainfall for Cooroy                       92   -
                                                                   02   =   1585mm



The MUSIC Modelling Guidelines for South East Queensland                    -
                                                                             Version 1 December 2010
details that Cooroy data for 1973 to 1983 should be used. This data has an annual average
Rainfall of 1600mm. It is considered that the 10 year period from 1992 2002 has a relatively
                                                                                     -




close mean annual Rainfall to the recommended 10 year period and as such is acceptable to
use in this case.



4.3       MUSIC Modelling Results


The MUSIC modelling program has been used to investigate the performance of various
treatment options in the treatment train. MUSIC version 5 is capable of incorporating rainwater
re-use in the model. These features have been          used in making comparisons between different
stormwater management systems for this report.




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1303, Kabara Hostel, Cooroy                 IWMP.doc                                     January 2013