Stormwater Compliance: MUSIC Modelling

In Queensland, the State Planning Policy sets out the best practice urban stormwater quality design objectives for development. The design objectives were derived using Version 3 of the industry-standard modelling software, the Model for Urban Stormwater Improvement Conceptualisation (MUSIC).  Since the objectives were derived, eWater have released three new versions of the MUSIC software to the industry.

Healthy Waterways recommends using MUSIC version 6 to ensure compliance with stormwater pollutant load reduction objectives, with the following parameters adopted when modelling bioretention filter media:

  • Minimum 30 mg/kg Orthophosphate (OP)
  • Minimum 400 mg/kg Total Nitrogen (TN)
  • other parameters in accordance with the MUSIC Modeling Guidelines (Water by Design, 2010)

Healthy Waterways has previously provided recommendations for modelling in MUSIC version 5. These values have been updated as shown above for MUSIC version 6. 

The values above are recommended in MUSIC version 6 because they are readily achieved by suppliers of filter media (based on our discussions with the industry), lower values may result in basins that are undersized, and they provide consistent results against best practice principles.

We are currently seeking informal feedback to develop objectives that deliver the best outcome in a cost-effective way. If you would like to contribute, please contact us.