Climate data including rainfall and evapotranspiration are essential inputs to MUSIC. MUSIC is a continuous simulation model and requires an input time series of rainfall data. If you intend to model without Melbourne Water provided rainfall templates, data is available from the Bureau of Meteorology at a 6 minute timestep for a number of gauges across Melbourne Water’s service area. The selection of a rainfall gauge and period should consider: • local rainfall patterns for the site of interest • completeness of record • representation of a range of conditions including wet and dry periods and a variety of storm events of varying size and antecedent dry periods • purpose of the model The choice of meteorological data is a balance between the level of accuracy required and the time and effort required for modelling. The templates Melbourne Water provides represent the rainfall variations across metropolitan Melbourne. The following periods are recommended: • 10 year period: A minimum period of 10 years for: • all Development Services / Drainage Scheme designs • modelling of areas including significant areas of pre-development, rural or pervious land. • Analysis of flow frequency objectives such as number of flow days, stream erosion index and flow frequency curves • 20+ year period: Municipal and larger integrated water management strategies, waterway flow analyses, analysis of large pervious catchments (> 100 ha).