First water determinations
The Resource Manager for northern Victoria hasannounced the first 2022/23 seasonal determinations, an updated outlook for 2022/23 water availability, and an updated assessment of the risk of spill in the Murray, Goulburn and Campaspe systems.
The Murray system starts 2022/23 with a seasonal determination of 94 per cent of high-reliability water shares (HRWS). The Goulburn and Loddon systems begin with 66 per cent HRWS.
The Campaspe system starts 2022/23 with 70 per cent HRWS. The Broken system opens with 38 per cent HRWS and the Bullarook system starts with 19 per cent HRWS.
Resource Manager Mark Bailey said the opening seasonal determination in Murray system was the highest since 2002/03.
“The reserves established last season enabled the Murray system to start with the highest seasonal determination in 20 years,” said Dr Bailey. “The opening seasonal determination in the Goulburn system is the highest since 2017/18.”
“All of the northern Victorian systems have started 2022/23 with an optimistic outlook,” said Dr Bailey.
“Improvements will come with continuing rainfall and runoff into the major storages, and the latest Bureau of Meteorology forecast favours above-average rainfall to September.
“Customers should consider the rainfall forecast and the updated outlook for seasonal determinations when planning their water needs this year.”
Dr Bailey urged Murray system customers to note the effect of continued releases from Lake Hume for airspace management. “The Murray-Darling Basin Authority is continuing to manage the rate of filling at Lake Hume. Entitlements holders in the Murray system should note a deduction from spillable water accounts will occur in mid-August after the volumes released during July are confirmed.
“The situation at Lake Hume means the risk of spill in the Murray system is effectively 100 per cent,” Dr Bailey said. “The risk of spill from Lake Eildon in the Goulburn system is about 80 per cent and the risk of spill from Lake Eppalock in the Campaspe system is about 20 per cent.”
Dr Bailey said the risk of spill assessment did not describe the chances of flooding this season. “The risk of spill is a water accounting assessment. It does not refer to flood risks downstream of the storages.”
The seasonal determinations for northern Victorian water systems on Friday, July 1 are:
Water System High-Reliability Water Share Low-Reliability Water Share
Murray 94% 0%
Broken 38% 0%
Goulburn 66% 0%
Campaspe 70% 0%
Loddon 66% 0%
Bullarook 19% 0%