Resource Manager releases 2018/19 Seasonal Determination Outlook Update

Tuesday 15 May, 2018

The Resource Manager for northern Victorian water systems today updated the outlook for 2018/19 seasonal determinations.

Northern Victorian Resource Manager Mark Bailey said the Goulburn, and Loddon systems are expected to start the 2018/19 water year with seasonal determinations of about 20 per cent of high‑reliability water shares (HRWS) or better.

The Murray system is expected to start with a seasonal determination of at least 40 per cent HRWS.

“The Campaspe system is expected to receive 100 per cent HRWS on the first 2018/19 announcement on July 2, 2018,” Dr Bailey said.

“Early season announcements in the Broken and Bullarook systems will be influenced by the volume carried over and catchment conditions.

“Carryover will be deliverable in systems under all scenarios.

“All of the northern Victorian systems are expected to have seasonal determinations of 100% HRWS by mid October 2018 under average inflow conditions.

“The updated 2018/19 outlooks have not changed significantly compared to the first outlook published in February. Conditions have been warm and dry across northern Victoria through autumn and storage levels are yet to increase.

“Recent rain has started to wet the catchments but more rain is needed before flows into the major storages cause storage levels to rise.

“Based on the historical flow record, it is estimated that the probability of spill during 2018/19 in the Goulburn system could be about 30 per cent and about 75 per cent in the Murray system. The probability of spill in the Campaspe system is expected to be about 50 per cent at the start of 2018/19. Customers may wish to factor this into their plans for the remaining weeks of 2017/18.”

Further detail on Outlook for the 2018/19 season

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

The scenarios assessed 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 in the Murray, Goulburn, Loddon, Broken and Bullarook systems.

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

Inflow Conditions 2 July 2018 15 August 2018 15 October 2018 15 February 2019
Wet 71% 92% 100% 100%
Average 61% 75% 100% 100%
Dry 53% 62% 87% 100%
Extreme Dry 42% 48% 58% 62%

 

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

Inflow Conditions 2 July 2018  15 August 2018 15 October 2018 15 February 2019
Wet 50% 100% 100% 100%
Average 33% 56% 100% 100%
Dry 24% 38% 55% 79%
Extreme Dry 20% 26% 32% 36%

 

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

Inflow Conditions 2 July 2018  15 August 2018  15 October 2018 15 February 2019
Wet 40% 44% 100% 100%
Average 0% 44% 100% 100%
Dry 0% 0% 21% 47%
Extreme Dry 0% 0% 0% 0%

 

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

Inflow Conditions 2 July 2018  15 August 2018  15 October 2018 15 February 2019
Wet 0% 100% 100% 100%
Average 0% 100% 100% 100%
Dry 0% 0% 9% 26%
Extreme Dry 0% 0% 0% 0%

 

Seasonal determinations under additional scenarios for the Goulburn and Loddon systems are available from the Northern Victorian Resource Manager website at www.nvrm.net.au/outlooks .

Outlooks for low-reliability water shares (LRWS) will be prepared during the 2018/19 season if seasonal determination are 100% HRWS and there is the possibility of LRWS being allocated.

Upcoming Resource Manager Announcements

  • The first 2018/19 seasonal determination announcement will be released on Monday 2 July 2018 and will include an assessment of the probability of spill in the Murray, Goulburn and Campaspe systems and an updated outlook.

For information about the Resource Manager for northern Victorian regulated water systems, including seasonal determinations and resource availability, please visit www.nvrm.net.au .