Irrigation season starts with a big splash

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The 2022-23 irrigation season has opened with high allocations that are likely to increase as the season goes on. Photo by Daneka Hill

High dam storages and continued forecasts for above-average rainfall are giving water authorities plenty of confidence as they calculate new-season water determinations.

On July 1, the northern Victoria resource manager and the NSW regulator released the first seasonal determinations for 2022-23.

In Victoria, the Murray system was allocated 94 per cent high-reliability water shares, making it the best in the region.

Second best was the Campaspe system on 70 per cent HRWS, followed by Goulburn and Loddon both on 66 per cent, Broken on 38 per cent and Bullarook with 19 per cent.

Low-reliability water shares all started the season on zero per cent, as they usually do.

Across the border in NSW, the highest allocations among regulated river water sources were the general security licences in the Lower Darling, Peel River, Upper Namoi, Hunter, Richmond and Paterson water sources.

All were allocated 100 per cent (or 1.0Ml/unit share).

The next best were the high-security licences in the Murray (97 per cent or 0.97Ml/unit share) and the Murrumbidgee (0.95Ml/unit share) systems.

General security licences in Murray and Murrumbidgee sat at 0.43Ml/unit share and 0.35Ml/unit share respectively.

Northern Victoria resource manager Mark Bailey said the opening seasonal determination in the Victorian Murray system was the highest since 2002-23 — two decades ago.

“The reserve established last season enabled the Murray system to start with the highest seasonal determination in 20 years,” Dr Bailey said.

“The opening seasonal determination in the Goulburn system is the highest since 2017-18.”

Dr Bailey said all of the northern Victorian systems had started the season with “an optimistic outlook”.

“Improvements will come with continued rainfall and run-off into the major storages, and the latest Bureau of Meteorology forecast favours above-average rainfall to September.”

Lake Hume continues to release water for storage management.

Dr Bailey urged Murray system entitlement holders to note a deduction from spillable water accounts will occur in mid-August.

“The situation at Lake Hume means the risk of spill in the Murray system is effectively 100 per cent,” he said.