Opening seasonal determinations and risk of spill assessment for 2015/16

Determination Data

Seasonal determinations for northern Victoria regulated river systems.

Further Information

The Resource Manager for northern Victoria today made the first seasonal determination announcement and low risk of spill declaration for 2015/16.

The Murray system starts 2015/16 with a seasonal determination of 35 per cent of high-reliability water shares (HRWS) and the Goulburn system starts with 42 per cent HRWS. The seasonal determination in the Campaspe system is 50 per cent HRWS and the Loddon system receives 37 per cent HRWS.

Resource Manager Mark Bailey said the Broken and Bullarook systems would both start 2015/16 on zero per cent HRWS, but carried over allocation can be delivered.

Dr Bailey declared a low risk of spill in the Goulburn and Campaspe systems. The risk of spill in the Murray system remains greater than the 10 per cent threshold.

“Inflows into the major storages have stayed very low,” Dr Bailey said. “There was very little improvement in stored resources during May and June.

“The first seasonal determinations of the new water year and the declaration of a low risk of spill for Lake Eildon and Lake Eppalock reflect the dry conditions currently being experienced.

“Seasonal determination improvements now depend on future inflows.”

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

Outlook for the 2015/16 season

“With the current dry conditions and concerns for what the El Niño event may mean for inflows during spring, we added a new ‘Extreme Dry’ outlook to inform water users of likely seasonal determinations under near-minimum inflows,” Dr Bailey said.

“Most northern Victorian systems have tracked close to the ‘Dry’ outlook category in recent months. This is expected to continue under the July to September climate outlook issued by the Bureau of Meteorology on June 25.”

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

Extreme Dry: Inflow volumes that have 99 chances in 100 (or 9.9 chances in 10) of being exceeded

The following tables summarise possible HRWS seasonal determinations in the Murray, Goulburn, Loddon, Campaspe and Broken systems through the 2015/16 season.

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

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

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

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

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

2015/16 Low-Reliability Water Share Outlooks

The dry conditions of 2014/15 mean reserves for 2015/16 are lower than in recent years and a reduced chance of seasonal determinations of low-reliability water shares. Inflows and use will define if seasonal determinations of low-reliability water shares occur in 2015/16.

Risk of spill assessment for the Murray, Goulburn and Campaspe systems

The risks of spill in the Goulburn and Campaspe systems during 2015/16 are below the 10 per cent threshold for a declaration to be made. The risk of spill in the Murray system is about 27 per cent.

Trading Opportunities

The Goulburn system’s inter-valley trade (IVT) account now owes about 80 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.

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 Murray system below 50 per cent. The current risk of spill limit allows 140 GL of net trade from New South Wales to Victoria.

Trading opportunities from New South Wales to Victoria are next updated on July 15, 2015.

Customers participating in the water trading market can monitor trade availability on the Water Register website, waterregister.vic.gov.au/water-trading/allocation-trading, from July 6, 2015 when the Water Register reopens.

The Murray-Darling Basin Authority 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 Murray-Darling Basin Authority website www.mdba.gov.au/river-data/barmah-choke.

Upcoming Resource Manager Announcements

• The next risk of spill in the Murray system will be issued on Friday July 10, 2015
• The next 2015/16 seasonal determination announcement will be released on Wednesday July 15, 2015 and will include an updated outlook.

For information about the Resource Manager for northern Victorian regulated water systems, including seasonal determinations, resource availability and carryover volumes, please visit www.nvrm.net.au. The status of Victorian shares of Murray storages is available at www.mdba.gov.au/what-we-do/managing-rivers/river-murray-system/water-sharing.

Information about El Niño is available from the Bureau of Meteorology at www.bom.gov.au/climate/enso.

Details of the July to September rainfall outlook are available at www.bom.gov.au/climate/outlooks.