Case study: source model used in Thomson environmental flow study

Source model offers more precise science in Thomson environmental flow study

Water for the environment gives our rivers, lakes and creeks the water it needs to survive. But before water is released as environmental flows the Victorian Government conducts an environmental flow study to know how much water to release and when.

This is because – at the risk of stating the obvious – plants and animals can’t talk. They can't tell us how much water they need to survive through summer or how often they need flushing flows to maintain their habitat. But models can help us understand how much water is needed to sustain the health of the environment and the pattern it needs to be delivered.

One approach is to create a 'natural' condition model that shows what the river would have been like before dams, channels and pipelines were built to inform how we should release water.

This is one of the models that was created for the Thomson River. The previous environmental flow study conducted on the Thomson was in 2003 and used hydrological modelling software called REsource ALlocation Model (REALM).

However, the REALM model could only represent monthly information, so fine details like a pulse of water that only lasts a few days were not captured. After 17 years the environmental flow study of the Thomson has been updated, now with a model using the Victorian Government’s new water modelling platform Source.

Source provides daily information giving decision-makers a more robust and defensible foundation to decide how much water the Thomson needs to survive for now and into the future.

Map of Thomson catchment