Update of seasonal determinations for 2014/15

Determination Data

Seasonal determinations for northern Victoria regulated river systems.

Further Information

Entitlement holders in the Murray, Goulburn, Broken and Loddon systems have received increased high-reliability water shares (HRWS) seasonal determinations in the latest announcement from the Resource Manager for northern Victoria.

The Murray system will increase by 19 per cent to 76 per cent and the Goulburn and Loddon systems will increase by 16 per cent to 90 per cent HRWS.

Resource Manager Mark Bailey said the Broken system would increase by 19 per cent to 34 per cent HRWS and Bullarook remained on zero per cent HRWS.

"Continuing rainfall across the northern Victorian catchments has increased inflows to all storages and made these increases possible," Dr Bailey said.

"While the small Bullarook system remains without a seasonal determination at the moment, there has been a significant improvement in the volumes of the system’s storages."

Dr Bailey said in addition to the volumes allocated this season, there was 425 GL carried over in the Murray system and about 456 GL in the Goulburn system.

"About 260 GL and 355 GL were held by private water share holders, including irrigators, in the Murray and Goulburn systems respectively," he said.

"The remaining volume is held by the environmental water holders and urban water corporations.

"Entitlement holders in the Campaspe system carried over about 26 GL."

Outlook for the 2014/15 season

The Broken system should receive 100 per cent HRWS by October 15 even under dry inflow conditions.

Dr Bailey said seasonal determinations of low-reliability water shares (LRWS) in the Murray, Goulburn and Loddon systems would depend on use and the volume of inflows during winter and spring, but should be available under wet conditions later in the season.

Possible LRWS seasonal determinations for the different inflow scenarios are being prepared and will be available in mid-August.

"The chances improve if inflows result in water being debited from spillable water accounts and water is used during periods of unregulated flows without release from storage," Dr Bailey said.

"Under average conditions Campaspe system LRWS seasonal determinations are expected to commence in mid-spring, but are unlikely to reach 100 per cent.

"There will be no LRWS seasonal determinations under dry conditions in the Campaspe system."

He said the full inflow record was used to assess seasonal determinations for a range of inflow scenarios. The scenarios for different inflow conditions were produced using the following terminology:

Wet: Inflow volumes that have 10 chances in 100 (or one chance in 10) of being exceeded.
Average: Inflow volumes that have 50 chances in 100 (or five chances in 10) of being exceeded.
Dry: Inflow volumes that have 90 chances in 100 (or nine chances in 10) of being exceeded

The following tables summarise possible HRWS seasonal determinations in the Murray, Goulburn and Loddon systems through the 2014/15 season.

Murray System Outlook for Seasonal Determination of High-Reliability Water Shares

Goulburn & Loddon Systems Outlook for Seasonal Determination of High-Reliability Water Shares

Trading opportunities

Allocation trade from New South Wales (NSW) to Victoria is limited to the lesser of a net annual volume of 200 GL or the volume that keeps the risk of spill in the Murray system below 50 per cent.

With the risk of spill in the Victorian Murray system greater than 50 per cent, trade from NSW into Victoria is limited to the volume of trade out of Victoria to NSW. The availability of trade from NSW into the Victorian Murray system will be recalculated on August 11 and the 10th day (or following business day) of each month thereafter.

The volume owed to the Murray system from the Goulburn system’s inter-valley trade account is currently about 160 GL. Trade from the Goulburn, Campaspe and Loddon systems to the Victorian Murray, or to NSW and South Australia, is allowed while the total volume owed to the Murray is less than 200 GL.

The volume in the Broken system’s inter-valley trade account is currently about 1,200 ML. Trade from the Broken system is allowed when the balance of this account is less than 1,500 ML. Further trade opportunities within this limit may be created if there is trade back into the Broken or if the river operator calls out water to meet downstream demand during the season.

Customers participating in the water trading market can monitor trade availability on the Water Register website waterregister.vic.gov.au/water-trading/allocation-trading .

Customers participating in the water trading market are advised that the Murray-Darling Basin Authority has announced that the trading of water allocations from above the Barmah Choke to downstream of the choke will continue in the 2014/15 water year. The Murray-Darling Basin Authority will regularly review the ability to trade across the Barmah Choke and may lift the relaxation at any time during the season.

Upcoming Resource Manager Announcements

The next seasonal determination announcement will be released on August 1. An updated probability of spill assessment for the Murray, Goulburn and Campaspe systems will be announced on August 11.

For further information go to www.nvrm.net.au, waterregister.vic.gov.au, www.mdba.gov.au and www.g-mwater.com.au.