Water managment, water markets

Northern Victorian Resource Manager releases 2017/18 Seasonal Determination Outlook update

15 May 2017

15 May 2017

The Resource Manager for northern Victorian water systems today updated the outlook for 2017/18 seasonal determinations.

Northern Victorian Resource Manager Mark Bailey said the Murray system is expected to start the 2017/18 water year with a seasonal determination of 50 per cent of high-reliability water shares (HRWS) or better. The Goulburn and Loddon systems are expected to start 2017/18 with seasonal determinations of about 30 per cent of HRWS or better.

“The Campaspe system is expected to receive 100 per cent HRWS on the first 2017/18 announcement on July 3, 2017,” Dr Bailey said.

“Early seasonal determinations in the Broken and Bullarook systems are influenced by the volume of carried over allocation and catchment conditions. Carryover will be deliverable in the Broken and Bullarook systems in all scenarios.

“All of the northern Victorian systems are expected to have seasonal determinations of 100% HRWS by mid October 2017 under average inflow conditions. Seasonal determinations against low‑reliability water shares are expected in the Campaspe system later this year, even if dry inflow conditions occur.

“It is unlikely that a low risk of spill will be declared in the Murray, Goulburn or Campaspe systems early in the 2017/18 season. The risk of spill in the Murray system during 2017/18 is about 50 per cent. The risk of spill in the Goulburn system is about 30 per cent. The Campaspe system has a 70 per cent risk of spill.

“Customers in the Murray, Goulburn and Campaspe systems should factor the risk of spill into their seasonal watering plans.”

Dr Bailey noted the Bureau of Meteorology predicted a 50 per cent chance of an El Niño weather pattern developing in the coming months. El Niño is often, but not always, associated with a drier than average winter-spring over eastern Australia.

Further detail on outlook for the 2017/18 season

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

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

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

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

Extreme Dry: Inflow volumes 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.