Case study

Melbourne Water

ProjectQuantifying the Urban Stormwater Component of Observed Stream Flows
ClientMelbourne Water
LocationMelbourne, Victoria, Australia
Completion2008
Disciplines/ServiceUrban Catchment Hydrologic Modelling
WRM ContactDavid Newton

The Challenge

Through its Central Region Sustainable Water Strategy, the Victorian Government aimed to secure the region’s water supplies over the next 50 years. The Strategy included a policy which recognised the substantial resource value of urban stormwater and delivers an innovative, common sense approach to stormwater harvesting in urban catchments.

No existing methodology was available to achieve the project objectives. As such, the project required an innovative approach based on a good understanding of urban hydrology.

Approach and Key Activities

The objective of the project was to develop a tool to facilitate real-time harvesting of stormwater flows in urban streams. The key element of the study was developing a way to identify, in real time, the additional runoff generated by impervious surfaces which could be taken from the stream without adverse impacts on environmental flows. The project developed a methodology to define the volume and timing of stormwater flows potentially available for harvesting.

The methodology was based on a novel approach to configuring the MUSIC hydrologic model which allowed urbanisation impacts to be quantified more easily. The method was tested on the Darebin Creek catchment on Melbourne’s northern outskirts.

Outcomes

The project developed a novel methodology for the identification of the stormwater component of urban streamflow and confirmed the useability of the approach by application to a case study catchment.

A paper detailing the methodology and findings from the study was prepared for the 2009 Hydrology and Water Resources Symposium in Newcastle.