Water management in the Barmah–Millewa Forest depends on gravity distribution from the River Murray. When river flows are above 15,000 ML per day downstream of Yarrawonga Weir, both sides of the forest are managed as a whole. When flows are below this, each side of the forest can be managed separately by operating the regulators individually. Below flows of about 10,500 ML per day downstream of Yarrawonga Weir, all regulators usually remain closed.
River regulation and water extraction from the River Murray has reduced the frequency, duration and magnitude of flood events in the Barmah–Millewa Forest. This has affected the diversity, extent and condition of vegetation communities and the habitat and health of dependent animal species.
Environmental water releases seek to protect critical habitat under dry conditions and build on unregulated flows and the delivery of consumptive water en route to maximise environmental outcomes when possible. As Barmah Forest is located in the upper reaches of the River Murray, environmental water delivered to the forest can often be used again at sites further downstream as part of multi-site watering events.