The Goulburn and Loddon systems seasonal determinations have increased from 37 per cent high reliability water shares (HRWS) to 40pc in today's update announcement.
The Resource Manager for northern Victoria announced an update to the 2020/21 seasonal determinations and outlook on Monday.
The Murray system moves from 19 per cent of high-reliability water shares (HRWS) to 24 per cent HRWS.
The Campaspe system moves from 40 per cent HRWS to 45 per cent HRWS. The Broken system increases from 30 per cent HRWS to 39 per cent HRWS.
Seasonal determinations in the Bullarook system increases from 5 per cent HRWS to 19 per cent HRWS.
Resource Manager Mark Bailey said rain led to the seasonal determination increases announced today.
"After falling during June and July, flows into the major storages have picked up following the rain of the past week," Dr Bailey said.
"More rain will bring further improvements in the seasonal determinations. The region's major storages historically record their highest flows between August and October," he said.
Dr Bailey said the latest Bureau of Meteorology seasonal outlook favoured above-average rainfall across the catchment areas for the three month period from September to November.
"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 southeast Australia," Dr Bailey said.
Dr Bailey advised entitlement holders to use the seasonal determination outlooks and weather information when planning their water needs in 2020/21.