Dr Bailey said the September 15 announcement was the first seasonal determination for Victorian Murray system low-reliability water shares for the 2022-23 water year.
“Low-reliability water shares in the Murray system reached a 100 per cent seasonal determination in the 2021-22 water year — this was achieved on February 15, 2022,” he said.
The system hit 100 per cent high-reliability water shares on August 1, the earliest its seasonal determination had reached 100 per cent in 20 years.
The Broken system has 100 per cent HRWS and has increased from 48 per cent LRWS to 69 per cent LRWS. The Goulburn, Loddon and Campaspe system seasonal determinations remain at 100 per cent HRWS.
Dr Bailey said rainfall continued to improve resources in all systems.
“All major storages across northern Victoria are nearing capacity as the rain continues,” he said.
“Most of the additional stored volume has increased reserves for the 2023-24 water year.
“The storage control releases made from Lake Hume during August contributed to the low-reliability water shares allocation announced today for the Murray system.
“The volume of Victorian resource released in August from Lake Hume was greater than the balance of Murray spillable water accounts. This means 100 per cent of the allocation held in these accounts will be deducted with this update.”
Dr Bailey said spillable water described any allocations greater than a customer’s total water share volume.
“When the dams are full, spillable water has to make way for inflows to support new allocations to all water shares,” he said.
“Entitlement holders do not lose any water through spills until after they have their full entitlement volume available in their allocation account.
“All of the water in spillable water accounts in Lake Hume was released during August to make way for further inflows that have supported increased reserves for next year and the seasonal determinations to low-reliability water shares announced this week.
“Consequently, all the allocation in Murray spillable water accounts is now gone.
“Increased seasonal determinations against low-reliability water shares are probable in the Murray system.
“These increases will move more allocation into spillable water accounts. These accounts will be affected by continued spills from Lake Hume.”
Dr Bailey said Goulburn-Murray Water continued to release water to slow the rate of rise at Lake Eildon.
“About 31 gigalitres will be deducted from Goulburn spillable water accounts today. That’s about eight per cent of the current volumes in those accounts,” he said.
“The deductions mean the additional volume needed for a Goulburn LRWS allocation is about 380 Gl.”
Allocation trade from NSW to Victoria is not currently possible because Victoria’s shares of Lake Hume and Dartmouth Reservoir are full. The opportunity for allocation trade is updated with each risk of spill announcement.
Learn more at: waterregister.vic.gov.au/about/news/267-trial-of-improved-trade-adjustment-methods
22°C