Low-reliability water share seasonal determination increases in the Murray system

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

The Murray system increases from 100 per cent of high-reliability water shares (HRWS) and 12 per cent of low-reliability water shares (LRWS) to 100 per cent HRWS and 72 per cent LRWS.

The Goulburn, Campaspe and Loddon systems remain at 100 per cent HRWS. 

Seasonal determinations in the Broken and Bullarook systems stay at the maximum possible 100 per cent HRWS and 100 per cent LRWS.

Resource Manager Mark Bailey said resources in the Murray system continued to improve with rainfall since the last assessment.

“Continuing flows into the Menindee Lakes and the upper Murray storages are the basis for today’s improvement,” Dr Bailey said.

“Releases to control the level in Lake Hume during December also contributed, with another 105 gigalitres deducted from spillable water accounts.

“After a short pause due to drier weather, the releases from Lake Hume to manage water levels restarted early in January. This means further deductions from Murray spillable water accounts will occur on February 15 when the volume released is confirmed.”

Dr Bailey said the other northern Victorian systems received smaller resource improvements.

“The Goulburn system needs another 480 gigalitres of water before reserves are sufficient for 2022/23 allocations to high-reliability water shares.”

The Bureau of Meteorology seasonal outlook for the February to April period does not strongly favour above- or below-average rainfall across eastern parts of northern Victoria and favours slightly drier conditions in the west. La Niña conditions continue in the tropical Pacific and are expected to remain until early autumn. La Niña conditions increase the likelihood of above-average rainfall totals in south-east Australia.

The seasonal determinations for northern Victorian water systems on Monday 17 January are:

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. Trade adjustments will occur in Dartmouth where the risk of spill is less than 5 per cent.

The current risk of spill in the Murray system allows 68 GL of net trade from New South Wales to Victoria to keep the risk at Dartmouth below 50 per cent. The volume available for trade has reduced since the last announcement due to increasing storage levels at Dartmouth. 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 interim trade rule means that from December 15, 2021, net trade is capped and the inter-valley trade account balance will be run down.

In accordance with the interim trade rule cap, after 15 December, additional trade opportunity is only created when allocation is traded back from the Victorian Murray system, New South Wales or South Australia into the Goulburn, Broken, Campaspe or Loddon systems. More details about the new trade rule are available at 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 risk of spill update will be released on Thursday 10 February 2022.
• The next 2021/22 seasonal determination announcement will be released on Tuesday 15 February 2022.
• The first outlook for 2022/23 seasonal determinations will also be released on Tuesday 15 February 2022.