Northern Victorian Resource Manager Updates 2025/26 Seasonal Determination Outlook
The Resource Manager for northern Victorian water systems today updated the outlooks for 2025/26 seasonal determinations.
Resource Manager Andrew Shields said conditions had been very dry since the first outlook was released.
“Catchment areas across northern Victoria have received little rainfall in recent months,” Mr Shields said. “As a result, flows into the major storages have been well below average.
“Flows into the Menindee Lakes provided some additional resource in the Murray system.
“Considering these factors and an estimate of the volume carried over, seasonal determinations in the Murray, Goulburn, and Loddon systems should begin 2025/26 with about 25 per cent high-reliability water shares (HRWS) or better.
“The Campaspe system is expected to receive 100 per cent HRWS on 1 July 2025 under all inflow conditions due to the reserves established during 2024/25.
“As annual systems, the seasonal determinations in the Broken and Bullarook systems rely on catchment conditions and the volume of carried over allocation.
“Due to low reserves, we anticipate seasonal determinations in both the Broken and Bullarook systems will start 2025/26 at zero per cent HRWS.
“Inflow conditions during 2025/26 will determine how seasonal determinations change during the year. Average inflow conditions should allow the Broken, Goulburn, Loddon and Bullarook systems to reach seasonal determinations of 100 per cent HRWS by mid-October 2025. Murray system seasonal determinations may not reach 100 per cent until December under average inflow conditions.
“Dry conditions and water released to meet demands through autumn has reduced storage levels in the Murray, Goulburn and Campaspe systems. The risk of spill is expected to be about 45 per cent at the start of July 2025 in the Murray and Campaspe systems. The risk of spill in the Goulburn system is expected to be about 30 per cent in early 2025/26.
“Customers in these systems should factor the risk of spill into their plans for the remaining months of 2024/25.”
Further detail on outlook for the 2025/26 Season
The Bullarook seasonal determination outlook for 2024/25 is 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 table summarises possible high-reliability water share seasonal determinations through the season and include a reference year to help users recognise the possible inflow conditions.
Murray System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
47% |
72% |
100% |
100% |
| Average |
41% |
49% |
90% |
100% |
| Dry |
35% |
40% |
57% |
85% |
| Extreme Dry |
31% |
32% |
36% |
40% |
Goulburn and Loddon System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
53% |
97% |
100% |
100% |
| Average |
36% |
60% |
100% |
100% |
| Dry |
31%
|
39% |
52% |
70% |
| Extreme Dry |
30% |
32% |
35% |
38% |
Broken System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
41% |
46% |
100% |
100% |
| Average |
0% |
46% |
100% |
100% |
| Dry |
0% |
0% |
0% |
6% |
| Extreme Dry |
0% |
0% |
0% |
0% |
Bullarook System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
0% |
100% |
100% |
100% |
| Average |
0% |
100% |
100% |
100% |
| Dry |
0% |
0% |
0% |
0% |
| Extreme Dry |
0% |
0% |
0% |
0% |
Seasonal determinations under additional scenarios for each system are available from the .
Upcoming Resource Manager Announcements
- The first 2025/26 seasonal determination announcement will be released on Tuesday, 1 July 2025 and will include an updated outlook and an assessment of the probability of spill in the Murray, Goulburn and Campaspe systems.