Northern Victorian Resource Manager Releases 2023/24 Seasonal Determination Outlook

The Resource Manager for northern Victorian water systems today 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 2022/23 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.

Murray System Outlook for Seasonal Determination of High-Reliability Water Shares

Goulburn and Loddon System Outlook for Seasonal Determination of High-Reliability Water Shares

Broken System Outlook for Seasonal Determination of High-Reliability Water Shares

Bullarook System Outlook for Seasonal Determination of High-Reliability Water Shares

Seasonal determinations under additional scenarios for each system are available from the Northern Victorian Resource Manager website at www.nvrm.net.au/outlooks.

Upcoming Resource Manager announcements

• The next 2022/23 risk of spill update will be announced on Friday March 10, 2023.
• The 2023/24 seasonal determination outlooks will be updated on Monday May 15, 2023.
• The first 2023/24 seasonal determination announcement will be released on Monday July 3, 2023 and will include an updated outlook and an assessment of the probability of spill in the Murray, Goulburn and Campaspe systems.