Inland Waters

Flow Regimes

A flow regime is a specific combination of the timing, size and duration of flow events in river systems. It is a key driver of river and floodplain ecosystems. Groundwater is often an important component of flow regimes and maintains the health of rivers, floodplain wetlands and other groundwater-dependent ecosystems.

The flow regimes of major rivers and tributaries in many basins are currently degraded, with 16 out of 29 basins having no more than 20% of the length assessed with flow regimes in good condition. The main pressures on flow regimes are the presence of dams and other barriers; extraction of water for consumption; regulation of flow; channel modification; and changes in land use. In many rivers and aquifers the current environmental water reserve is inadequate and vulnerable, placing environmental values at risk. Over the past 11 years, the scarcity of surface water in Victoria has reached levels that exceed historical precedent. Under projected climate change, streamflow may decrease by up to 50% across much of the State by 2070. Both the current drought and climate change compound pressures on flow regimes.

This section presents the current condition of flow regimes for major rivers and tributaries based on the 2004 Index of Stream Condition assessment. Ongoing threats to flow regimes are identified, and implications of the current condition are discussed. This section also provides an overview of management responses and presents recommendations relating to flow regimes in Victoria.

Part 4.3.1 - Flow Regimes (PDF - 3.2 MB)