Water

Seasonal determinations increase in all but one system as new water year begins

By Rodney Woods

Seasonal determinations in Victoria have started higher than they finished last season in all systems except Bullarook, due to flows into the major storages in recent months.

Northern Victoria's resource manager Mark Bailey announced the first 2020-21 seasonal determinations and an updated outlook and risk of spill in the Murray, Goulburn and Campaspe systems on July 1.

The Murray system starts 2020-21 with a seasonal determination of eight per cent of high-reliability water shares and the Goulburn and Loddon systems begin with a 35 per cent HRWS seasonal determination.

The Campaspe system starts 2020-21 with a seasonal determination of 32 per cent HRWS, while the Broken system, which spent most of last season stuck on zero, opens with 17 per cent HRWS.

Instead, the Bullarook system starts 2020-21 with zero per cent HRWS.

In comparison, at the start of the 2019-20 season, the Murray, Goulburn and Loddon systems all started with a seasonal determination of two per cent HRWS, while the Campaspe system started on 26 per cent, the Bullarook system started with 19 per cent and the Broken system started on zero per cent.

“Flows into the major storages since the start of April have helped secure operating requirements for 2020-21 and enabled water to be allocated at the start of the new water year,” Dr Bailey said.

“The catchments are wet and responding to rain.

“This means we are more likely to see runoff entering the storages when rain falls.

“We need the rain to continue over coming months to increase storage levels and the seasonal determinations.”

In terms of the the risk of spill, Victoria's share of the volume in Lake Hume gives the Murray system about a 60 per cent risk of spill, while the risk of spill from Lake Eildon in the Goulburn system is about 20 per cent and the risk of spill from Lake Eppalock in the Campaspe system is about 50 per cent.

VFF Water Council chair Richard Anderson said it was important irrigators get a 100 per cent allocation after several dry years.

“It's a positive to start on July 1 with something,” he said.

“Hopefully it continues and we get close to full allocations.

“If we can get 100 per cent seasonal determinations as early as possible, it means more confidence and we can accurately plan what we are going to plant.”

Across the border, NSW Murray irrigators will be starting their water year back on zero per cent general security, despite receiving a late-season announcement last season of three per cent.