Rising storage levels lift seasonal determinations

By Jamie Salter

Flows into major storages have slightly increased seasonal determinations in the Murray, Broken, Goulburn and Loddon systems.

The Murray system moved from eight per cent high-reliability water shares to 15 per cent, the Broken system rose from 17 per cent to 30 per cent, the Campaspe system increased from 32 per cent to 40 per cent and the Goulburn and Loddon systems went up by two per cent, reaching 37 per cent HRWS.

Seasonal determinations in the Bullarook system remain on zero per cent HRWS.

For NSW Murray, general security allocations have increased from zero per cent to two per cent — the first early season allocation in two years.

Northern Victoria resource manager Mark Bailey said storage level increases were the main contributor to the updated 2020-21 outlook.

“Flows into the major storages increased the volume of water available for allocation,” Dr Bailey said.

“Improved catchment flows downstream of the major storages have effectively filled mid-river storages such as Waranga Basin in the Goulburn system and Lake Victoria in the Murray system.

“Future flows into Lake Eildon and Lake Hume will define seasonal determination improvements in the Goulburn and Murray systems until the mid-river storages and catchment flows begin supplying water in August.”

Dr Bailey said the latest Bureau of Meteorology seasonal outlook slightly favoured above-average rainfall across the catchment areas during the August to October period.

“The rainfall outlook for August and September does not favour wetter or drier conditions over the catchment areas,” he said.

“The bureau has issued a La Nina watch meaning the chance of a La Nina forming is around 50 per cent in late winter or early spring.

“La Nina events may support rainfall across south-east Australia.”

Dr Bailey advised entitlement holders to use the seasonal determination outlooks and weather information when planning their water needs over the next year.