Opening seasonal determinations and risk of spill update for 2021/22

Thursday 1 July, 2021

The Resource Manager for northern Victoria today announced the first 2021/22 seasonal determinations, an updated outlook for 2021/22 water availability, and an updated assessment of the risk of spill in the Murray, Goulburn and Campaspe systems.

The Murray system starts 2021/22 with a seasonal determination of 21 per cent of high-reliability water shares (HRWS). The Goulburn and Loddon systems begin with 33 per cent HRWS.

The Campaspe system starts 2021/22 with 14 per cent HRWS. The Broken system opens with 5 per cent HRWS and the Bullarook system starts with 40 per cent HRWS.

Resource Manager Mark Bailey said opening seasonal determinations were assisted by the reserves established during 2020/21 and recent flows into the major storages.

“Reaching 100 per cent HRWS in all systems, and 100 per cent of low-reliability water shares in the Broken and Bullarook systems, in 2020/21 meant handy reserves were available for 2021/22,” Dr Bailey said.

“And after a relatively dry autumn, recent rainfall has generated flows into the major storages and added to water availability in all systems.

"The catchments are wet and responding to rain. Any rainfall is producing runoff into the rivers and major storages. We need the rain to continue over coming months to boost storage levels and increase the seasonal determinations. 

“This is the first time since 2012/13 that all northern Victorian systems have received a non-zero seasonal determination at the start of the new water year.

“The latest Bureau of Meteorology seasonal outlook favours above average rainfall across the catchments between July and September.

"The Bureau noted that conditions in the Indian Ocean are typical of a negative Indian Ocean Dipole, which could bring above-average rainfall in winter and spring.”

The recent rain and flows have influenced the storage risk of spill assessments for 2021/22. Victoria’s share of the volume in Lake Hume gives the Murray system about a 55 per cent risk of spill. The risk of spill from Lake Eildon in the Goulburn system is about 30 per cent and the risk of spill from Lake Eppalock in the Campaspe system is about 30 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.”

Dr Bailey advised entitlement holders to use the seasonal determination outlooks and weather information when planning their water needs in 2021/22.

The seasonal determinations for northern Victorian water systems on Thursday, July 1.
Water System High-Reliability Water Share Low-Reliability Water Share
Murray 21% 0%
Broken 5% 0%
Goulburn 33% 0%
Campaspe 14% 0%
Loddon 33% 0%
Bullarook 40% 0%

Trading opportunities

Allocation trade applications will start to be processed from 10:00 am on July 1, 2021 when the Victorian Water Register opens for the new water year.

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 the both Hume and Dartmouth reservoirs below 50 per cent. The current risk of spill in the Murray system allows 200 GL of net trade from New South Wales to Victoria. This volume will be updated with each risk of spill announcement. Customers can find out more about trade adjustments on the  Water Register website.

A new interim trade rule for trade from the Goulburn, Broken, Campaspe and Loddon systems to the Victorian Murray system, New South Wales and South Australia will be in effect from 1 July 2021 to 30 June 2022, replacing the previous rule that has been in place since 2013. The new trade rule means that up 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.

As at 10.00 am today, around 142 GL of Inter-Valley Trade is owed to the Murray and there is about 48 GL of trade opportunity. More details about the new trade rule are available at the  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.

Trade from the Broken system re-opens at the start of each water year and is allowed when the Broken system’s IVT account owes less than 1,500 ML to the Goulburn system.

Customers participating in the water trading market can monitor trade availability on the  Water Register website from July 1, 2021 when the Water Register reopens.

The Murray-Darling Basin Authority (MDBA) has announced that trading of water allocations from above the Barmah Choke to downstream of the Choke is restricted 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 risk of spill in the Murray, Goulburn and Campaspe systems will be updated on Monday July 12, 2021.
  • The next 2021/22 seasonal determination announcement will be released on Thursday July 15, 2021 and will include an updated outlook.