The 2025-26 irrigation season will open with about half the water available at the same time last year.
The Victorian Murray system will start with a seasonal determination of 39 per cent of high-reliability water shares. The Goulburn and Loddon systems will begin with 31 per cent HRWS.
Last year, the opening allocation for Murray was 63 per cent HRWS, while Goulburn and Loddon were both 69 per cent.
The Campaspe system starts 2025-26 with 100 per cent HRWS, the same as 2024-25.
The Broken and Bullarook systems both start this year with zero per cent HRWS. Last year, Broken opened with five per cent and Bullarook with zero.
There are no opening low-reliability water shares in any system, as was the case last year.
All systems (except Bullarook) ended the 2024-25 water year on 100 per cent HRWS, with the Broken and Campaspe systems also receiving some LRWS.
The 2025-26 irrigation season opens on August 15.
Northern Victoria resource manager Mark Bailey said the opening seasonal determinations were lower than recent years, except in the Campaspe system.
“Drier conditions through 2024-25 meant we had fewer reserves for the opening seasonal determinations compared to the last few years,” Dr Bailey said.
“The Campaspe system was the exception and secured enough reserves for a 100 per cent seasonal determination.
“More water is needed in the Broken and Bullarook systems before seasonal determinations can increase.
“Recent rainfall in the catchment areas is welcome, but continued rainfall is needed over the coming months to increase storages levels and seasonal determinations across all systems.”
Current levels for the major Goulburn-Murray Water storages are: Lake Eildon is at 57.71 per cent (compared to 88.59 per cent at the same time last year); Hume Dam, 38.82 per cent (66.63 per cent); Dartmouth Dam, 66.83 per cent (94.47 per cent); Lake Nillahcootie, 43.97 per cent (77.77 per cent); Lake Eppalock, 56.55 per cent (90.33 per cent); and Cairn Curran Reservoir, 38.63 per cent (70.12 per cent).
“With below-average storage flows during May and June, the risks of spill have decreased since the last update was released in May 2025,” Dr Bailey said.
“The spill risk in both the Murray and the Campaspe systems is 40 per cent. In the Goulburn system, the risk of spill from Lake Eildon is about 25 per cent.”
Dr Bailey said the risk of spill assessment did not describe the chances of flooding this season.
“The risk of spill is a water accounting assessment. It does not refer to flood risks downstream of the storages.”
The possibility of increased allocations before August 15 and beyond will depend on rain and subsequent inflows across the catchments.
Tables that summarise the estimated HRWS seasonal determinations through the season for different inflow scenarios in the Murray, Goulburn, Loddon, Campaspe, Broken and Bullarook systems are available at: https://nvrm.net.au/outlooks/current-outlook
Seasonal determinations under additional scenarios for each system are available at: https://nvrm.net.au/outlooks/outlook-comparison
Trading opportunities
New water year trade opportunity opening times and trade limits are available on the Water Register website at: https://waterregister.vic.gov.au/water-trading/allocation-trading
Allocation trade from NSW to Victoria is limited to the lesser of a net annual volume of 200 Gl or a volume that keeps the risk of spill in Victoria’s share of both Hume and Dartmouth reservoirs below 50 per cent.
The current risk of spill from Victoria’s share of Hume and Dartmouth allows 200 Gl of allocation trade from NSW to Victoria.
The volume available for trade is updated monthly with each risk of spill announcement.
Next update
The risk of spill in the Murray, Goulburn and Campaspe systems will be updated on Thursday, July 10.
The next 2025-26 seasonal determination announcement will be released on Tuesday, July 15. An updated outlook will be released with this announcement.