MCU14/0106 & OPW15/0001 Appendix E - Stormwater Management Plan

Noosa Civic
Stormwater Management Plan




3                Stormwater Quality Modelling
3.1              Environmental Values and Water Quality Objectives
In order to satisfy the requirements of the State Planning Policy (DSDIP, 2013) and Noosa Shire Council, it
will be necessary to treat runoff from the site to ensure that the Environmental Values of downstream
receiving waters are protected. To achieve this, it will be necessary to treat water to meet the water quality
objectives defined in the State Planning Policy.
The relevant load based water quality objectives applicable to the site are listed in Table 3-1.
Table 3-1        Operational Phase Performance Criteria

              Pollutant              Load Based Reduction Target
      Total Suspended Solids                  80% reduction
          Total Phosphorus                    60% reduction
           Total Nitrogen                     45% reduction
   Litter (sized 5mm or greater)              90% reduction


The following section details the modelling undertaken to confirm that an appropriate level of treatment can
be achieved.

3.2              Pollutant Impact Assessment
A detailed pollutant export analysis was carried out using eWater’s Model for Urban Stormwater
Improvement Conceptualisation (MUSIC) v6.01. The analysis was carried out in accordance with the latest
guidelines and data as defined in:
          ‘Water Sensitive Urban Design Technical Design Guidelines for South East Queensland’ (Healthy
           Waterways, 2006); and
          ‘MUSIC Modelling Guidelines Version 1.0’ (Water By Design, 2010).
In accordance with the above guidelines, the meteorological data and rainfall-runoff parameters adopted for
modelling are detailed in Table 3-2 below.
Table 3-2        MUSIC Model Meteorological Data and Rainfall-Runoff Parameters

           Source Node                                              Treatment Type
 Rainfall station                  Noosa Shire Council – Cooroy Composite – Station 40059
 Time step                         6 minute
 Modelling period                  1/01/1973 - 31/12/1989
 Mean annual rainfall (mm)         1600
 Evapotranspiration                Cooroy Composite – Station 40059
                                   (Reference: Table 3.1, Water by Design, 2010)
 Rainfall runoff parameters        Urban Residential (Reference: Table 3.7 Water by Design, 2010)
 Pollutant export parameters       Urban Residential split catchments (Reference: Table 3.8 Water by Design, 2010)


A split land use catchment breakdown was adopted in the model. Details of the catchment breakdown and
source nodes are provided in Table 3-3 and Table 3-4, with the model layout presented in Appendix D.




QIC Noosa Civic Pty Ltd                              Version Final                                          11 May 2015
J13041R2_Final SWMP.docx                         Commercial in Confidence                                        Page 8