Hattah Lakes is a complex of more than 20 semipermanent freshwater lakes over an area of 48,000 hectares. The lakes complex forms part of the Hattah–Kulkyne National Park. Located adjacent to the River Murray in north-west Victoria, the ecology of the lakes and floodplain is strongly influenced by flooding regimes.
The Hattah Lakes system is naturally filled when there are high flows in the River Murray. When floods recede some individual lakes hold water for years. The high flows that cause floods in the lakes are less than they were before, when the Murray system was unregulated.
In the absence of regular high flows in the River Murray, large-scale engineering works were completed under the Living Murray program to improve water regimes at Hattah Lakes under low-flow conditions. Pumps and regulators are used to deliver, retain and discharge water from the floodplain, to provide the water regimes that support the environmental values in the system.