Water allocations rise as irrigation season starts

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Storages like Lake Eildon have received good inflows following rain this month, leading to an increase in seasonal determinations. Photo by darren linton

Water allocations for the Goulburn and Loddon systems have risen in time for the start of the irrigation season, and the forecast is for all major northern Victorian systems to have 100 per cent by mid-October.

Northern Victoria resource manager Mark Bailey released the latest update on the August 15 start to the irrigation season.

The Goulburn and Loddon systems have increased high-reliability water shares from 76 per cent to 93 per cent and Campaspe has moved from 77 per cent to 82 per cent, while Broken has increased to 57 per cent.

The outlook forecasts that, under future average inflows, the districts should reach 100 per cent by October 17.

The Murray system seasonal determination remains unchanged at 100 per cent HRWS.

Dr Bailey said rainfall during the first half of August enabled the seasonal determination increases.

“After a below-average July, this month’s rainfall has generated good streamflow responses in all catchments,” he said.

“The Goulburn and Loddon systems have particularly profited from improved storage volumes.

“Another 1040 gigalitres is needed in the Murray system before the reserves for high-reliability in 2023-24 are secure and low-reliability seasonal determinations can commence.

“This volume will reduce when system operating requirements and demands are met without releasing water from storage.”

Dr Bailey confirmed the scale of the first deductions from Murray spillable water accounts this season following releases through July to manage Lake Hume close to the full supply level.

“A deduction of about 115 Gl will be made with today’s announcement,” he said.

“This is about 27 per cent of the current volume held in the spillable accounts.

“As releases to manage the Lake Hume volume continue, Murray system entitlement holders should expect further deductions from spillable water accounts in the September 15 seasonal determination update.”

Dr Bailey said continued rainfall was likely, with longer term predictions favouring wetter conditions.

“The latest Bureau of Meteorology forecast suggests above-average rainfall will continue through to December.”