Promising start to next season’s water allocations
Victorian Murray system allocations for high-reliability water shares look set to open around 85 per cent for the 2022-23 season, and the Goulburn, Campaspe and Loddon systems about 50 per cent.
Northern Victoria resource manager Mark Bailey said the reserves collected in the 2021-22 season provided a strong foundation for 2022-23 Victorian water availability, which was reflected in the updated outlooks.
“While operating needs are fully met, early season water availability in the Broken and Bullarook systems will depend on catchment flows,” Dr Bailey said.
“Average inflow conditions should allow the Murray, Campaspe and Bullarook systems to reach seasonal determinations of 100 per cent HRWS by mid-August 2022.
“The same conditions in the Goulburn, Broken and Loddon systems would provide 100 per cent HRWS in mid-September.”
Dr Bailey said carryover volumes in the Murray and Goulburn systems were expected to be close to 900,000 megalitres in each system.
“Storage levels are higher than this time last year and so is the volume of unused allocation. This is not unexpected, given the wetter conditions during the traditional irrigation months,” he said.
“Early season use that reduces the amount of water committed plus continued inflows into the storages will increase the chances of allocations to low-reliability water shares.
“Wetter than average inflow conditions for a sustained period are needed in the Murray and Campaspe system before LRWS allocations can commence. In the Goulburn, inflows need to be closer to the wet outlook scenario.
“Scenarios where LRWS are allocated in the Murray and Goulburn systems will see deductions from spillable water accounts.
“The Goulburn system risk of spill in 2022-23 is currently about 70 per cent and about 40 per cent in the Campaspe system.
“Victoria’s share of Hume and Dartmouth are both full, which means flows in the Murray system would need to be extremely low to avoid a deduction from spillable water accounts in 2022-23.
“Customers in these systems should factor the risk of spill into their plans for the remaining weeks of 2021-22.”
ACROSS THE BORDER
Indicative opening allocations for the NSW Murray system provided by the NSW Department of Planning and Environment are 30 per cent for general security water and 97 per cent for high security water.
The department said in its water allocation statement the opening allocations were conservative and based on a dry outlook.
Forecast general security allocations by November 1 under a range of outlooks for the NSW Murray system are: (extreme dry) 30 per cent; (very dry) 35 per cent; (dry) 51 per cent; (mean) 110 per cent; and (wet) 110 per cent.