Seasonal determinations increase for Murray and Bullarook

By Jamie Salter

High-reliability water shares for the Murray and Bullarook systems have increased, according to Goulburn-Murray Water's latest 2020-21 seasonal determinations.

Announced on August 3, the update shows the Murray system moved from 15 per cent of high-reliability water shares to 19 per cent, while the Bullarook system increased from zero per cent HRWS to five per cent.

Seasonal determinations in the Goulburn, Broken, Campaspe and Loddon systems remain unchanged at 37, 30, 40 and 37 per cent HRWS respectively.

Northern Victoria resource manager Mark Bailey said continued dry conditions during July after a dry June had slowed the water availability improvements seen in the previous three months.

“Rainfall in July was below average in the catchment areas,” Dr Bailey said.

“After a very dry June, the continued low rainfall meant stream flows slowed appreciably.

“Flows into the major storages in the Goulburn, Broken, Campaspe and Loddon systems in the past fortnight were close to the estimates.

``That means we didn’t pick up more resource for allocation in these systems.”

Dr Bailey said mid-river storages such as Waranga Basin in the Goulburn system and Lake Victoria in the Murray system were effectively full.

“Flows into Lake Eildon, Lake Hume and Dartmouth Dam plus any supply that is met from catchment flows will define seasonal determination improvements in the Goulburn and Murray systems over the next few months,” he said.

Dr Bailey said the latest Bureau of Meteorology seasonal outlook still favoured above-average rainfall across the catchment areas for the three-month period from August to October.

“The outlooks for August and September do not favour wetter or drier conditions over the catchment areas,” Dr Bailey said.

“The bureau’s El Niño-Southern Oscillation outlook remains at La Niña watch, meaning the chance of a La Niña forming is around 50 per cent in late winter or early spring.

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

Dr Bailey has advised entitlement holders to use the seasonal determination outlooks and weather information when planning their water needs in 2020-21.