MUSIC Auditor updated for new Melbourne Water MUSIC Guidelines

Melbourne Water have released new MUSIC Guidelines and the MUSIC Auditor has now been updated to support these.

Users can now choose between the 2010 and 2016 Melbourne Water MUSIC Guidelines when submitting a summary report file for auditing.

The new guidelines introduce a range of updates including soil parameters, rainfall templates and other changes.

Soil parameters
Updated soil parameters were developed for use within the Melbourne Region based on available calibrated models. These are most suitable for areas with clay soils of at least 0.5 to 1.0 m depth and are derived from calibrations ranging from the northwest, north and southeastern parts of Melbourne.
The change from the existing guidelines will result in a reduction in runoff volumes from pervious areas consistent with observations of field data. Users should apply judgement as to whether these are suitable for their particular application and adjustment may be needed for sites with sandy soils, unusual groundwater and baseflow conditions or different climate and slope conditions..

Rainfall data sets
There are also a new set of 10 year rainfall periods for the six rainfall regions across Melbourne based on revised analysis of the latest data available. Both mean annual rainfalls and data quality were analysed to select the periods. These allow more reliable modelling of rainwater and stormwater reuse systems with a range of rainfall and drying periods and support wetland water level and spell analysis. The new rainfall periods also provide consistency with the Constructed Stormwater Wetlands Manual which requires a minimum of 10 years of rainfall data.

Pollutant concentrations
Support for representation of varying surface types with different pollutant concentrations is now provided and there is improved guidance throughout to help users set up models with confidence.

Inundation frequency analysis
Guidance is provided for preparing a flux file for use with the Wetland Analysis Tool to assess wetland water level patterns and increase confidence that these will support the plants selected.

These changes represent a significant improvement upon the existing guidance to support the development of more robust models