FULL water storages combined with a 50 per cent chance of another La Nina in 2022-23 are driving management strategies in the River Murray System for the year ahead, according to the MDBA’s 2022-23 annual operating outlook.
Murray–Darling Basin Authority (MDBA) river management executive director Andrew Reynolds said southern Basin storages were at an unusually high level heading into the irrigation season and it was likely that wet conditions and high flows would persist for at least the next few months.
Mr Reynolds said healthy flows continue to enter the Murray from the Murrumbidgee River, the Goulburn River and the other Victorian tributaries.
“Although rainfall eased off somewhat in the past couple of months, we’re approaching what is typically the season of highest inflows, and the Bureau of Meteorology is also forecasting a 50 per cent chance of another La Nina developing later this year,” he said.
“At Hume Dam, we have been in and out of flood operations for the past 12 months and this is likely to continue into spring.
“As always, we’ll work closely with Bureau of Meteorology and WaterNSW, and will communicate any significant changes to communities downstream of the dam.”
As at August 8, the Menindee Lakes are at 115 per cent capacity, Lake Victoria is at 62 per cent, Hume Dam is at 95 per cent and Dartmouth Dam at 97 per cent.
The MDBA said it would consider whether there was a need to start accessing water from the Menindee Lakes to fulfil demand in the Murray system as the year progresses.
“The fact that we did not need to draw water from the Menindee Lakes last summer underscores how unusual this long period of wet weather and high flows has been,” Mr Reynolds said.
“Given the high levels of water in storage, the risk of a shortfall in water delivery to entitlement holders this year is relatively low, however the risk could increase if conditions dry off and water demands ramp up quickly during a period of hot weather.
“It’s also notable that substantial amounts of water for the environment will be delivered through the system this year, including to the Barmah–Millewa Forest, unless natural flows exceed environmental targets.”
Conditions are evaluated based on Bureau forecasts and advice, inflow data, predicted inflows and demands and historical records, to determine how to best manage the system.
