General News
23 February, 2023
Seasonal outlook
The Resource Manager for northern Victorian water systems released the first outlook for 2023/24 seasonal determinations. Resource Manager Mark Bailey said the events of this season underpinned water availability for 2023/24.“Very wet conditions...
The Resource Manager for northern Victorian water systems released the first outlook for 2023/24 seasonal determinations.
Resource Manager Mark Bailey said the events of this season underpinned water availability for 2023/24.
“Very wet conditions through 2022/23 provided maximum seasonal determinations in all systems and good prospects for 2023/24 allocations,” Dr Bailey said.
“Based on estimated use at the end of the season, opening seasonal determinations in the Murray system are likely to be at least 80 per cent of high-reliability water shares (HRWS).
“Seasonal determinations in the Goulburn and Loddon systems are expected to start at about 75 per cent HRWS or better,” Dr Bailey added.
“The Campaspe system has enough resource available to allocate 100 per cent HRWS under all conditions on the first 2023/24 announcement on July 3, 2023,” Dr Bailey said.
“Carried over allocation volumes and catchment conditions will influence early season availability in the Broken and Bullarook systems, which have smaller storages and fewer reserves” Dr Bailey added.
“Average inflow conditions should allow the Murray, Goulburn, Loddon and Bullarook systems to reach seasonal determinations of 100 per cent HRWS by mid-August 2023,” Dr Bailey said. “The same conditions in the Broken system would provide 100 per cent HRWS in mid-October.
“The Murray and Goulburn systems need average or better inflow conditions for seasonal determinations to low-reliability water shares (LRWS),” Dr Bailey said. “LRWS allocations in the Campaspe system are likely early in the season under average inflow conditions.
“Early season use that reduces the amount of water committed, plus continued inflows into the storages, will increase the chances of allocations to LRWS.”
“Any scenarios in which LRWS is allocated in the Murray and Goulburn systems will see deductions from spillable water accounts,” Dr Bailey said.
“The risk of spill in the Murray, Goulburn and Campaspe systems in 2023/24 will depend on how much water is released from the storages in the next few months to meet demands,” Dr Bailey noted. “The risk of spill in each system is expected to be at least 70 per cent at the start of July 2023.”
“Customers in these systems should factor the risk of spill into their plans for the remaining months of 2022/23.”
Further Detail on Outlook for the 2023/24 Season
The outlooks for 2023/24 seasonal determinations are based on historical flow records that have been adjusted to match climate conditions observed since 1975. The outlook scenarios presented are:
Wet Inflow volumes to major storages that are greater in 10 years out of 100
Average Inflow volumes to major storages that are greater in 50 years out of 100
Dry Inflow volumes to major storages that are greater in 90 years out of 100
Extreme Dry Inflow volumes to major storages that are greater in 99 years out of 100
The following tables summarise the estimated high-reliability water share seasonal determinations through the season for each scenario in the Murray, Goulburn, Loddon, Broken and Bullarook systems.