Seasonal Determination update for season 2017/18 VIC

 Wednesday 15 November, 2017

Seasonal determination update for 2017/18


The Resource Manager for northern Victoria today updated the 2017/18 seasonal determinations.

The Goulburn system and the Loddon system both increase from 93 per cent to 94 per cent high-reliability water shares (HRWS).

A seasonal determination of 20 per cent of low-reliability water shares (LRWS) is available in the Broken system. The Broken system also has 100 per cent HRWS.

The LRWS seasonal determination in the Campaspe system increases from 30 per cent to 33 per cent. The Campaspe system also has 100 per cent HRWS.

The seasonal determination in the Murray system remains unchanged at 100 per cent HRWS and the Bullarook system remains at 100 per cent HRWS and 100 per cent LRWS.

Resource Manager Mark Bailey said tributary inflows in the Broken system downstream of Lake Nillahcootie had improved system resources.

"While low, the tributary inflows helped meet operating commitments and allowed more water in Lake Nillahcootie to be used to improve seasonal determinations," Dr Bailey said.

"The small improvements announced for the seasonal determinations in the Goulburn and Loddon systems also came from tributary flows meeting some of the delivery commitments."

With water borrowed from the Barmah Forest now repaid and a low risk of spill declared earlier this month, the Resource Manager has calculated the shortfall to a LRWS seasonal determination in the Murray system.

"The current shortfall to a low-reliability water share seasonal determination in the Murray system is 860 GL," Dr Bailey said.

"Closure of the shortfall during 2017/18 will depend on the reduction of current commitments and improved inflows to increase resources."

The seasonal determinations for northern Victorian water systems on Wednesday, November 15 are:

Water System

High Reliability Water Share

Low Reliability Water Share

Murray

 100%

0% 

Broken

 100%

20%

Goulburn

 94%

0%

Campaspe

 100%

33% 

Loddon

 94%

0%

Bullarook Creek

 100%

100%


Outlook for the 2017/18 season

The Resource Manager uses historical flow records to assess the seasonal determinations for a range of inflows to the major storages. The scenarios are:


Wet:
 Inflow volumes to major storages that are greater in 10 years out of 100

Average: Inflow volumes to major storages that are greater in 50 years out of 100

Dry: Inflow volumes to major storages that are greater in 90 years out of 100

Extreme Dry: Inflow volumes to major storages that are greater in 99 years out of 100


The following tables summarise possible high-reliability water share seasonal determinations through the season and include a reference year to help users recognise the possible inflow conditions.


Goulburn and Loddon System outlook for seasonal determination of high-reliability water shares 

Inflow conditions

Similar inflow season

15 December 2017

15 February 2018

Wet

 2016/17

100% 

100%

Average

 2005/06

100%

 100%

Dry

 2015/16

97%

 100%

Extreme Dry

 2006/07

95%

 98%


Seasonal determinations under additional scenarios for each system are available from the Northern Victorian Resource Manager website at www.nvrm.net.au/outlooks.


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 Murray system below 50 per cent. Following the declaration of a low risk of spill in the Murray system on November 10, the trade limit allows 200 GL of net trade from New South Wales to Victoria.

The Goulburn system's inter-valley trade (IVT) account owes about 266 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.

Customers participating in the water trading market can monitor trade availability on the Water Register website.


Customers can monitor trading opportunities across the Barmah Choke on the MDBA website.


Upcoming Resource Manager Announcements

  • The risk of spill for the Campaspe system will be updated on Monday 11 December 2017.
  • The 2017/18 seasonal determination will be updated on Friday 1 December 2017.

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