Outlook - 16 May 2022

The Resource Manager for northern Victorian water systems today updated the outlook for 2022/23 seasonal determinations.

Resource Manager Mark Bailey said the reserves collected this season provided a strong foundation for 2022/23 water availability, which was reflected in the updated outlooks.

“Based on estimated carryover and current weather trends, opening seasonal determinations in the Murray system are likely to be around 85 per cent of high‑reliability water shares (HRWS)," Dr Bailey said.

“In the Goulburn, Campaspe and Loddon systems, the opening seasonal determinations are expected to start at about 50 per cent HRWS.

“While operating needs are fully met, early season water availability in the Broken and Bullarook systems will depend on catchment flows.

“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 noted that carryover volumes in the Murray and Goulburn systems are 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 (LRWS). 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.”

Further detail on outlook for the 2022/23 season

The outlooks for 2021/22 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, Campaspe, 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

Campaspe 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

Additional outlook scenarios for each system are available from the Northern Victorian Resource Manager website www.nvrm.net.au/outlooks.

Upcoming Resource Manager announcements

• The last 2021/22 risk of spill update will be announced on Friday June 10, 2022.
• The first 2022/23 seasonal determination announcement will be released on Friday July 1, 2022 and will include an updated outlook and an assessment of the probability of spill in the Murray, Goulburn and Campaspe systems.