The Murray-Darling Basin Authority anticipates that the water volume in the Menindee Lakes could surpass 640 gigalitres late this week, triggering water sharing arrangements agreed between New South Wales, Victoria and South Australia.
MDBA Executive Director of River Management, Andrew Reynolds, said between 800 and 950 gigalitres could flow from the Darling River into the lake system in far-west New South Wales, according to the latest information from WaterNSW.
"This is the most significant volume of water to enter the lakes in five years, thanks to the heavy autumn rainfall in the northern catchments," Mr Reynolds said.
"This water is critical for the wellbeing of the Baakindji people and the confidence of the Menindee community as a whole. The lakes are also important for local tourism and a recognised site for fish and bird breeding."
As determined by the Basin states in the Murray-Darling Basin Agreement, when the storage volume reaches 640 gigalitres, or 37 per cent capacity, water in the lakes is available to meet demands downstream. In managing the River Murray System, the MDBA can call on that water on the states' behalf. The lakes continue to be actively managed by the NSW Government.
The state governments require the MDBA to maximise the total volume of water available across the River Murray System. This means water is often drawn from the Menindee Lakes in preference to other storages such as Hume and Dartmouth dams, which have lower rates of evaporation and seepage.
"Operating the Menindee Lakes is challenging, and whenever we call on water on behalf of Basin states we consider community needs and enhancing environmental outcomes as well as the needs of downstream water users who order water," Mr Reynolds said.
"Given the current state of the river system, significant releases of water are not likely from the Menindee Lakes until late spring or summer, although we will continue to evaluate this. If conditions are dry in coming weeks, that might change with rising demand for water but the volume required by the states from the Menindee Lakes in that circumstance would be relatively small."
The last time the lakes were shared between New South Wales, Victoria and South Australia ended in December 2017, when levels dropped below 480 gigalitres. Since then, in accordance with the Murray-Darling Basin Agreement, water in the lakes has been reserved for New South Wales use.
