Stormwater Management Report

8.2 Proposed Stormwater Treatment Train

All site stormwater runoff from the site is proposed to pass through a bio-retention basin adjacent to the southern
boundary of the allotment prior to discharging through the existing drainage infrastructure.

The efficiency of the proposed treatment train has been identified using the Model for Urban Stormwater Improvement
Conceptualisation (MUSIC V6.2) developed by Monash University.

A schematic layout of the treatment train, as input into the MUSIC model, is shown in Figure 3 below.




                                      Figure 3 - MUSIC Version 6.2 Schematic Layout

The Rainfall Runoff Parameters for the source catchment nodes have been taken from Table 3.7 of Water By Design’s
– MUSIC Modelling Guidelines, Version 1.0 (2010) and are shown in Table 2 below.

                                           Table 3 – Rainfall Runoff Parameters

                               Rainfall threshold (mm/day)                        1
                                                Pervious Area Properties
                               Soil storage capacity (mm)                         18
                               Initial storage (% of capacity)                    10
                               Field capacity (mm)                                80
                               Infiltration capacity coefficient – a              243
                               Infiltration capacity exponent - b                 0.6
                                                Groundwater Properties
                               Initial depth (mm)                                 50
                               Daily recharge rate (%)                            0
                               Daily baseflow (%)                                 31
                               Daily deep seepage rate (%)                        0

The pollutant load concentrations for the source catchment has been taken from Water By Design’s – MUSIC
Modelling Guidelines, Version 1.0 (2010) using the concentrations recommended for industrial areas.

 The model was run for an average rainfall recorded at Caloundra Rainfall Station 40040, between the years 2000-
2010 and using a 6 minute time step. The mean annual rainfall for Caloundra area is 1543mm.

HR DESIGN                                         Reference No: 18-0165B                                    Page 8 of 15