It might have been six years in the making but irrigators across northern Victoria and the Riverina have finally got their day in court with the MDBA.

The MDBA used overbank transfers to flood the bush four times during 2017-2019 which resulted in little or zero allocation for irrigators, causing extreme financial and mental stress.

NSW Murray general security received 51 per cent allocation in 2017-18, then zero in 2018-19 and a paltry 3 per cent in May 2020.

Week one of the court case saw opening statements take up all of the allocated time.

The plaintiffs (irrigators from both sides of the river) described the case as one of significant public importance, with the operation of the water resource and control of it by the MDBA, having significant real world consequences for the lives and economic lives of irrigators across the basin.

The basin accounts for

• 85 per cent of Australian irrigated use
• 41 per cent of Australia’s gross production
• Employs over 45 per cent of cultural workers

The MDBA argued to the Court it has no duty of care in the management of the Murray River.

It was agreed by the MDBA overbank transfers have the highest water loss rate somewhere between 36 and 41 per cent.

Barrister Tony Bannan SC said:

“We say and the evidence shows this, that the use of the overbank transfer system is exceedingly rare in the history of the operation of the river Murray system and is a blunt and inefficient instrument, if you like, to be avoided at all costs.”

MDBA calculations state 55GL of operational water went overbank in 2018-19 and 420GL in 2019-20.

The MDBA accepts 23GL of the 55GL and 135GL of the 422GL was ‘lost’.

The plaintiffs contend the volumes were higher and this ‘lost’ water would otherwise have been available for allocation to farmers and irrigators.

“We say that they were decisions that were not reasonable, not reasonably required, and contrary to their own operating parameters, guidelines and assessments at the time.

“And we say that involved mismanagement and flawed planning.

“We submit there is no evidence to suggest it even consulted its own plans in doing what it did.

“And we also submit that it relied on flawed modelling tools,” Mr Bannan said.

Section 10 of the Water Act makes it clear one of the objects is to ensure the economic

wellbeing of the community which would include irrigators.

When it comes to the 2018-19 breach the plaintiff stated “one of the criticisms we make of the Authority is they failed to follow their own plan, which was to deliver certain volumes of water to Lake Victoria much earlier in the year.

“One of the answers that our learned friends brought up is, you can’t criticise us for that because we were delivering maximum flow at 9,500, or thereabouts, at certain points in the year from Yarrawonga Weir. And they positively assert to this court…. there was no further capacity to send water further down.

“What they appear to have overlooked is that during a period when they thought they were sending a certain amount of water downstream, they had forest regulators open for the purpose of deliberate – what they call- in channel environmental watering.

“…… to put it mildly it demonstrates extreme incompetence.”

The MDBA argued they acted conservatively to manage the risk of shortfalls and overbank flows are one of the ‘recognised levers’ to supply water downstream.

Counsel for the MDBA Sophie Callan SC said bulk transfer around the choke were rare due to transmission losses but that ‘does not render it unreasonable’.

This article appeared in The Koondrook and Barham Bridge Newspaper, 21 August 2025.