Opening seasonal determination and risk of spill update for 2020/21

Wednesday 1 July, 2020

The Resource Manager for northern Victoria today announced the first 2020/21 seasonal determinations and an updated outlook and risk of spill in the Murray, Goulburn and Campaspe systems.

The Murray system starts 2020/21 with a seasonal determination of 8 per cent of high-reliability water shares (HRWS). The Goulburn and Loddon systems begin with a 35 per cent HRWS seasonal determination.

The Campaspe system starts 2020/21 with a seasonal determination of 32 per cent HRWS. The Broken system opens with 17 per cent HRWS.

The Bullarook system starts 2020/21 with 0 per cent HRWS.

Resource Manager Mark Bailey said opening seasonal determinations are higher than last season in all systems except the Bullarook system due to flows into the major storages in recent months.

“Flows into the major storages since the start of April have helped secure operating requirements for 2020/21 and enabled water to be allocated at the start of the new water year,” Dr Bailey said.

“The catchments are wet and responding to rain. This means we are more likely to see runoff entering the storages when rain falls. We need the rain to continue over coming months to increase storage levels and the seasonal determinations.

“The latest Bureau of Meteorology seasonal outlook slightly favours below-average rainfall across the catchment areas during the July to September period.

“The Bureau has issued a La Niña watch meaning the chance of a La Niña forming is around 50 per cent in late winter or early spring.

“La Niña events may support rainfall across southeast Australia.”

The risk of spill is consistent with the June 2020 assessment. Victoria’s share of the volume in Lake Hume gives the Murray system about a 60 per cent risk of spill. The risk of spill from Lake Eildon in the Goulburn system is about 20 per cent and the risk of spill from Lake Eppalock in the Campaspe system is about 50 per cent.

Dr Bailey advised entitlement holders to use the seasonal determination outlooks and weather information when planning their water needs in 2020/21.

The seasonal determinations for northern Victorian water systems on Wednesday, July 1 are:

Water System High-Reliability Water Share Low-Reliability Water Share
Murray 8% 0%
Broken 17% 0%
Goulburn 35% 0%
Campaspe 32% 0%
Loddon 35% 0%
Bullarook 0% 0%

Trading opportunities

Allocation trade applications will start to be processed from 12:00 pm on July 2, 2020 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.

The Goulburn system’s inter-valley trade (IVT) account owes about 235 GL to the Murray system. The Goulburn, Campaspe and Loddon systems can trade to the Victorian Murray system, New South Wales and South Australia while the total volume owed to the Murray system is less than 200 GL.

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. The current balance of the IVT account is about 700 ML.

Customers participating in the water trading market can monitor trade availability on the  Water Register website, from July 2, 2020 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 Friday July 10, 2020.
  • The next 2020/21 seasonal determination announcement will be released on Wednesday July 15, 2020 and will include an updated outlook.