Public servants warned dam spills were risk to Labor before state election

The risk of dams spilling over and becoming an election issue for Labor was flagged by an independent water authority before the government moved to scrap a desalination order in 2022.

Internal emails obtained by The Age show water officials flagged the “material reputational risk” of spills while households were paying for desalination in the days before then-water minister Harriet Shing canned the rest of the 15 gigalitre order, citing independent advice.

The revelation is found in hundreds of pages of correspondence, obtained by The Age under freedom of information laws, which includes one email where a public servant warned that the opposition could weaponise high water levels as a failure of government two months before the state election.

At the time, water storage levels were nearing 95 per cent capacity – the highest since 1997 – and wet La Niña conditions were forecast to continue. Within weeks, the Thomson Dam would spill for the first time in 26 years, before the devastating October 2022 floods.

The documents show that on September 15, 2022 – eight days before the public announcement to scrap the remaining water order – Melbourne Water’s “early unofficial advice” was that it was “not possible or feasible to cancel or defer” the order.

A Melbourne Water presentation, dated September 13 and prepared for a quarterly storage management meeting, proposed managing rising storage levels by releasing water. It did not canvass cancelling the desalination order.

Yet days later, Shing said the government would abandon the rest of the 15 gigalitre order.

Under Victoria’s water governance framework, statutory water corporations provide independent, technical advice and manage water supply in the public interest.

But correspondence from South East Water shows staff assessed the political implications of a dam spill in the week before the decision.

In one email, a water authority employee wrote that Melbourne Water’s technical information offered limited insight on its own. However, “overlaying with our internal knowledge”, it warned of political risks for the government.

Chief among them was the “material reputational risk” of water flowing over the Thomson Reservoir spillway while desalinated water was entering the system. In an election year, the employee warned, that could be “picked up by the opposition as a failure of the current government”.

“Irrespective of the opposition position there would likely be news articles about the community paying for desalinated water while the system is spilling.”

Melbourne Water consults other water authorities before providing its advice to government, which it insists is independent.

But the correspondence appears to support insider claims that the process had become politicised. A source who worked in the water sector in 2022, who was unable to speak publicly, said there was an impression that the minister wanted the order cancelled for political reasons.

Announcing the cancellation on September 23, Shing said Melbourne Water had provided independent advice recommending the Victorian government drop the remainder of the order. She said she had accepted this advice and the desalination order was halted immediately.

Melbourne households and businesses pay for desalination through their bills. Suspending the order made bills nominally cheaper for the rest of the year.

Dr Erin O’Donnell, an Associate Professor in water policy at the University of Melbourne Law School, said it was “extremely unfortunate” that political implications were highlighted by South East Water.

“It is outside their remit as independent agencies, and in doing so, they undermine both their independence and their technical expertise,” she said.

O’Donnell said there are good reasons to suspend a desalination order when water storage levels are high. Melbourne households and businesses should not have to pay for more water than they need, she said, and the authorities are required to act as efficiently as possible.

Dam spills also raise the risk of floods, she said, and desalination has environmental impacts.

“Future water security should always be part of planning, but when the storages are full or nearly full, then there is limited value in adding more water at that point,” O’Donnell said.

“Decisions that balance the risks of acquiring more water than is needed and the need to provide water security into the future are highly technical. This is exactly why we need independent water authorities that can provide frank, fearless, evidence-based advice to ministers – who should then decide for themselves what the political implications are, and how these should be managed.”

The trove of documents also reveals the minister’s office shared a media brief with Melbourne Water on September 20, the details of which were redacted, hours before the water authority provided its advice to cancel the order to Shing’s department.

Board minutes further reveal South East Water rounded up the customer savings from the cancellation, in part because of “political sensitivity” and uncertainty from the La Niña rains.

Large sections of regional Victoria have since struggled through drought, and the water outlook for 2026 warned that there is a chance Melbourne residents could return to water restrictions.

The government has since started considering plans for a second desalination plant or an expansion of the existing Wonthaggi site to prepare for future water demand and dry spells in a changing climate.

The minister’s office, Melbourne Water and South East Water did not respond directly when asked if political implications had influenced the independent authorities or the advice.

“We put the safety of Victorians first by cancelling the 2022 desalination order to help prevent avoidable flooding – this was based on expert advice from Melbourne Water following unusually high rainfall and storage levels,” a government spokeswoman said.

“We built the Victorian desalination plant to make sure Victorians have access to safe drinking water when they need it.”

A Melbourne Water spokeswoman said the authority provided independent advice to the government each year.

“Per the advice at the time, Melbourne Water considered the unusually high rainfall and determined that a desalinated water order was no longer necessary.”

South East Water strategy and stakeholder general manager Karen Lau said desalination was an essential part of Melbourne’s water supplies.

“Melbourne Water consults with South East Water when advising the Victorian government on desalinated water orders,” she said.

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