Update to 2021/22 seasonal determinations

Monday 16 August, 2021

The Resource Manager for northern Victoria today updated the 2021/22 seasonal determinations.

The Murray system moves from 46 per cent of high-reliability water shares (HRWS) to 52 per cent HRWS. The Goulburn and Loddon systems increase from 59 per cent HRWS to 66 per cent HRWS.

The Campaspe system moves from 59 per cent HRWS to 87 per cent HRWS. The Broken system increases from 67 per cent HRWS to 68 per cent HRWS.

Seasonal determinations in the Bullarook system remain unchanged at 100 per cent HRWS and 100 per cent of low-reliability water shares.

Resource Manager Mark Bailey said sustained streamflows from wet catchments contributed to the increases announced today.

“Water continues to enter the major storages during a period of low demand,” Dr Bailey said.

“Even without much rainfall, the volume received in the past fortnight has been above our estimates and become available for higher allocations.

“Victorian Murray entitlement holders are reminded that the Murray-Darling Basin Authority pre-released water from Lake Hume for several days in the first half of August.

"The volume released will be accounted at the next seasonal determination update, but around 150 GL to 180 GL of Victorian resource needs to spill before spillable water accounts are affected.

“As the Murray system seasonal determination is greater than 50 per cent, resource improvements will contribute to increasing the high-reliability water share seasonal determination and allocating the volume owed to the Barmah Millewa Forest Environmental Water Allocation."

Dr Bailey said the latest Bureau of Meteorology seasonal outlook favours above-average rainfall across the catchment areas for the three month period from September to November.

“The Bureau has advised that the negative Indian Ocean Dipole continues, which increases the likelihood of above-average rainfall totals in south-east Australia.”

The seasonal determinations for northern Victorian water systems on Monday 16 August are:
Water System High-Reliability Water Share Low-Reliability Water Share
Murray 52% 0%
Broken 68% 0%
Goulburn 66% 0%
Campaspe 87% 0%
Loddon 66% 0%
Bullarook 100% 100%

Trading opportunities

Allocation trade from New South Wales 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 the Victoria’s share of both Hume and Dartmouth reservoirs below 50 per cent. While the risk of spill at Lake Hume is effectively 100 per cent, the risk of spill at Dartmouth is less than 5 per cent and this is where trade adjustments will occur.

The current risk of spill in the Murray system allows 200 GL of net trade from New South Wales to Victoria as this would increase the risk at Dartmouth to about 15 per cent. This volume will be updated with each risk of spill announcement. Customers can find out more about trade opportunities and a trial of improved trade adjustment methods on the  Victorian Water Register website.

An interim rule for trade from the Goulburn, Broken, Campaspe and Loddon systems to the Victorian Murray system, New South Wales and South Australia is in effect from 1 July 2021 to 30 June 2022, replacing the previous rule that had been in place since 2013. The new trade rule means that until December 15, 2021, trade is allowed whenever the total amount owed from the Goulburn to the Murray, including the Lower Broken Creek, is less than 190 GL. From December 15, 2021, net trade will be capped and the inter-valley trade account balance will be run down.

The volume currently committed to the Murray is 190 GL, meaning trade from the Goulburn, Broken, Campaspe and Loddon systems to the Victorian Murray system, New South Wales and South Australia is closed. More details about the new trade rule are available at the  Victorian Water Register Website.

The Goulburn, Campaspe and Loddon systems can trade from the Victorian Murray system, New South Wales and South Australia while the total volume owed to the Murray system is greater than zero.

Customers participating in the water trading market can monitor trade availability on the  Victorian Water Register Website.

The Murray-Darling Basin Authority (MDBA) is restricting trade of water allocations from above the Barmah Choke to downstream of the Choke to protect the delivery of downstream water entitlements. Customers can monitor trading opportunities across the Barmah Choke on the  MDBA website.

Upcoming Resource Manager announcements

  • The next 2021/22 seasonal determination announcement will be released on Wednesday 1 September 2021.
  • The next risk of spill update will be released on Friday 10 September 2021.