RFI - Engineering correspondence

A MUSIC Model was created to confirm non-worsening of water quality resultant from the
subdivision. The parameters for the source nodes are based on the SEQ MUSIC Modelling
Guidelines V3 from Water by Design.
These include:
   · Storm and rainfall data for Cooroy Composite (Station 40059) years 1973-1982 as per
       Table A1.1
   · Rainfall Runoff Parameters for Commercial and Industrial Catchments as per Table A1.2
   · Pollutant export parameters for Industrial Catchments as per Table 3.9,

Provision was made for a small amount of additional hardstand (post development) across the
four lots in the event of an impervious surface pad or container being located on site outside of
any formal MCU approval. This is not planned for and is incorporated in the model as incidental
use only for robustness of the modelling.




Figure 1: MUSIC Model Layout and Pre-Post Development Comparison Results.




 2023 - Bullgate                                                                        Page 2 of 3