For stormwater treatment modelling using MUSIC, a
meteorological data template is required based on rainfall and potential
It is recommended the following minimum periods are used:
- 10 years for WSUD treatment performance and
- 20 years for stormwater harvesting, large scale
integrated water management plans and strategies (>100 ha) and catchments
with an impervious fraction less than 20 percent or where pervious flows are substantial.
Two rainfall regions were
identified for the City. Areas with rainfall less than 500 millimetres annually were
designated “Little River” and those with rainfall greater than 500 millimetres annually
were designated “Geelong North” to coincide with the Bureau of Meteorology
(BOM) station names. The rainfall regions are attached below.
The modelling timestep should be less than:
shortest time of concentration.
shortest treatment detention time under design flows.
For the City, all models should be
run at a 6 minute modelling timestep. The use of larger timesteps reduces model
accuracy and can increase the variability of results while allowing it to run
faster. There is little justification for using larger timesteps for most
practical modelling purposes with modern computers. Where a different timestep
is proposed, it must be agreed in writing by the City and comply with the above
The climate templates are available for download below.
The user should select the appropriate template for the project location and type of analysis.
Note that as the templates have been infilled to improve quality, they cannot be reproduced by creating a template directly from the raw data.
Where an alternative climate
template is proposed to be adopted, it must be based on a similarly rigorous
approach as that used to determine the above (see Appendix B: Design Note 3) and its use is
subject to agreement in writing by the City.