Northern Victorian Resource Manager Releases 2021/22 Seasonal Determination Outlook
The Resource Manager for northern Victorian water systems today updated the outlook for 2021/22 seasonal determinations.
Resource Manager Mark Bailey said rainfall over the past three months had done little to improve the volumes in storages.
“Opening seasonal determinations in the Murray, Goulburn, Campaspe and Loddon systems are likely to be less than 25 per cent of high‑reliability water shares (HRWS),” Dr Bailey said. “We currently expect the Broken and Bullarook systems to start 2021/22 at zero per cent.
“Flows in the storages between now and the end of June, plus final carried over allocation volumes, will determine early seasonal determinations,” Dr Bailey said.
“The Murray system outlook includes the impact of the Menindee Lakes recently becoming a shared resource available to Victoria,” noted Dr Bailey. “It also includes borrow and subsequent repayment of allocation from the Barmah-Millewa Forest Environmental Water Account during the season, which is a regular component of Murray seasonal determinations.
“Carried over allocation is fully deliverable in all systems from July 1,” Dr Bailey added.
The Resource Manager used climate-adjusted flow records and assumptions about water use to the end of the water year to determine the initial risk of spill in the Murray, Goulburn and Campaspe systems.
“The Murray system risk of spill is currently about 45 per cent,” Dr Bailey said. “The risk is around 30 per cent in the Goulburn and also about 30 per cent in the Campaspe system.”
Dr Bailey noted the Bureau of Meteorology climate outlook for June to August favours wetter than average conditions across all of northern Victoria.
“Customers in these systems may wish to factor this into their plans for the remaining months of 2020/21.”
Further Detail on Outlook for the 2021/22 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
| Wet |
42% |
58% |
100% |
100% |
| Average |
29% |
39% |
64% |
98% |
| Dry |
17% |
26% |
43% |
60% |
| Extreme Dry |
11% |
15% |
19% |
26% |
Goulburn and Loddon System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
46% |
89% |
100% |
100% |
| Average |
31% |
50% |
100% |
100% |
| Dry |
22% |
33% |
46% |
60% |
| Extreme Dry |
19% |
23% |
29% |
33% |
Campaspe System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
86% |
100% |
100% |
100% |
| Average |
18% |
64% |
100% |
100% |
| Dry |
12% |
17% |
27% |
28% |
| Extreme Dry |
12% |
12% |
12% |
12% |
Broken System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
31% |
35% |
100% |
100% |
| Average |
0% |
35% |
100% |
100% |
| Dry |
0% |
0% |
17% |
36% |
| Extreme Dry |
0% |
0% |
0% |
0% |
Bullarook System Outlook for Seasonal Determination of High-Reliability Water Shares
| Wet |
47% |
100% |
100% |
100% |
| Average |
0% |
100% |
100% |
100% |
| Dry |
0% |
14% |
26% |
100% |
| Extreme Dry |
0% |
0% |
0% |
0% |
Additional outlook scenarios for each system are available from the Northern Victorian Resource Manager website ( www.nvrm.net.au/outlooks
Outlooks for low-reliability water shares (LRWS) will be prepared during the 2021/22 season if seasonal determination are 100% HRWS and there is the possibility of LRWS being allocated.
Upcoming Resource Manager announcements
- The first 2021/22 seasonal determination announcement will be released on Thursday July 1, 2021 and will include an updated outlook and an assessment of the probability of spill in the Murray, Goulburn and Campaspe systems.