Environmental water clogs Hume and Dartmouth dams

VICTORIA’S share of the Murray River storages — Dartmouth and Hume dams — is choked with 514,000 megalitres of environmental and urban water.

VICTORIA’S share of the Murray River storages — Dartmouth and Hume dams — is choked with 514,000 megalitres of environmental and urban water.

That volume equates to 46 per cent of all the water available to Victorian water users in the Murray-Darling Basin’s largest storages.

Irrigators fear Victoria’s 50 per cent share of the storage space in Hume and Dartmouth dams may soon fill, leading to what’s termed an internal spill of incoming winter and spring inflows to NSW’s share of the dams.

The concern for irrigators is the water spilling into NSW’s share of the dams could have been stored and used to secure higher and earlier 2017-18 allocations, had the environment water holders not soaked up so much of the dams’ space.

“Rather than an internal spill going to NSW, maybe we need to discuss whether that water is released from the dam for the environment and taken off its seasonal allocation, rather than off irrigators,” Victorian Farmers Federation water council chairman Richard Anderson said.

As of the start of May, Victoria had filled about 80 per cent of its share of Hume and Dartmouth. In contrast, NSW has filled only about a third of its Dartmouth storage space and less than 60 per cent of its share of Hume.

Much of the problem stems from the environmental water users holding on to water during one of the basin’s wettest seasons and its inability to release water in the midst of floods.

Northern Victoria Resource Manager data shows Victorian and Commonwealth environmental water holders used just 74,000 megalitres of the 438,000ML they were allocated in 2016-17, against their Victorian Murray entitlements.

Carry-over, trade and unused urban water corporation allocations bring the total to 514,000ML, or 46 per cent of water allocations in storage.

In contrast, irrigators used 840,000ML of the 930,000ML they were allocated this season and hold a total of 609,000 on the Murray, equal to 56 per cent of stored allocation water.

Commonwealth Environmental Water Holder David Papps said he actively used carry-over to optimise the effectiveness of Commonwealth environmental water in delivering environmental benefits critical to the health of the Murray-Darling system.