Menindee releases increase
WaterNSW plans to increase releases from the Menindee Lakes system from 18 Gl/day to 23 Gl/day to maintain storage capacity and protect infrastructure under rules governing flood operations.
Increases started on May 27, with the plan at this stage for reaching a release rate at Weir 32 of 23 Gl/day by early June.
Recent modelling indicates between 1150Gl and 1550Gl is making its way down the Barwon-Darling River from the northern Murray-Darling Basin.
This is an increase from earlier estimates of 800Gl to 1200Gl and is due to continued significant rainfall across the northern basin in southern Queensland, the border rivers and NSW tributaries in recent weeks.
WaterNSW said releases were not due to increase until May 27 to allow for the community and downstream landholders to be advised by emergency agencies, and to provide time for any Broken Hill residents with property in Menindee to take action to protect assets.
Some graziers and environment groups have questioned why releases weren’t increased earlier so wetlands and productive land could have received a much-needed drink.
Grazier Angus Whyte said a good flood would have been welcomed after large sections dried up in 2019.
“Every centimetre over the high flow level of 18,000 megalitres a day results in more floodplain being inundated, more trees and plants watered, more food for river life, fish, frogs, yabbies and turtles,“ Mr Whyte said.
WaterNSW operations executive manager Ronan Magaharan said the increased inflow projections warranted the transition to flood operation rules.
“With the move into flood operations, the rules allow us to exceed 18 Gl/day to maintain airspace and safeguard the lakes’ infrastructure,” he said.
“WaterNSW will work with the Bureau of Meteorology to monitor inflows and river heights, and the NSW State Emergency Services in managing flood impacts.”
Almost 5400Gl has entered the lakes since February 2021, equivalent to more than three times the full storage capacity of the Menindee Lakes.
Access information about river heights and flows via WaterNSW’s website.