“The MDBA restarted pre-releases of water from Lake Hume on September 3,” Dr Bailey said in his spill update on September 10.
“This action helped control the rate of rise as water flowed into the storage and the MDBA have transitioned into managing the storage level close to full supply.
“The pre-releases made from Lake Hume in August reduced the volume of rules-based accounts only.
“The September pre-releases will again affect those accounts, but may cause deductions from spillable water accounts if the volume released is large enough.
“Any deductions from spillable water accounts will be determined in early October and included in the October 15 seasonal determination assessment.”
Dr Bailey said the situation for the two other spillable water systems was quite different.
“In the Goulburn system, the risk of spill from Lake Eildon is about 20 per cent and the risk of spill is also about 20 per cent from Lake Eppalock in the Campaspe system.”
Dr Bailey said the risk of spill assessment related to water accounting and did not describe the chances of flooding in the Murray, Goulburn or Campaspe systems this season.
Allocation trade from NSW to Victoria is limited to the lesser of a net annual volume of 200 Gl, or a volume that keeps the risk of spill in Victoria’s share of both Hume and Dartmouth reservoirs below 50 per cent.
While the risk of spill at Lake Hume is effectively 100 per cent, the risk of spill at Dartmouth is about 10 per cent, which is where trade adjustments will occur.
The current risk of spill in the Murray system allows 200 Gl of net trade from NSW to Victoria as this would increase the risk at Dartmouth to about 40 per cent. This trade volume will be updated with each risk of spill announcement.
Find out more at: https://www.waterregister.vic.gov.au/
9°C