Northern Victorian seasonal irrigation determinations open at good levels

System reserves have underwritten the determinations in the Murray, Goulburn, Campaspe and Loddon systems.

But the Broke and Bullarook systems have started the year with low or no allocation.

They are now depending on rainfall for any change.

The good levels follow on the back of high opening allocations last year, which were the best in more than 25 years.

The opening allocations are:

Last season most irrigation districts received a 100pc HRWS allocation and a 100pc Low Reliability Water Shares allocation by the end of the season.

This saw low average prices across the board.

The Dairy Australia Production Inputs Monitor in May put prices at an average of $21 a megalitre - not as low as the prices in 2023-24 but still well below the prices earlier this decade, when water exceeded $500/ML.

Resource manager Mark Bailey said the opening seasonal determinations reflected reserve availability across the systems.

"Reserves secured during 2023/24 have underwritten the opening seasonal determinations in the Murray, Goulburn, Campaspe and Loddon systems," he said.

"The storages in these systems are holding large volumes despite recent months of below-average rainfall.

"Growth in the seasonal determinations in the Broken and Bullarook systems will depend on rainfall and resulting catchment flows during the early months of the water year."

Dr Bailey said the latest Bureau of Meteorology outlook favoured slightly below-average rainfall between July and September.

"The risk of spill in the Murray system is 85 per cent and 80 per cent in the Goulburn system," he said.

"In the Campaspe system, the risk of spill from Lake Eppalock is about 70 per cent.

"The risks have fallen since the last update, consistent with below-average storage flows in May and June."

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," he said.

"It does not refer to flood risks downstream of the storages."