Lake Eildon technical risk assessment slammed as too narrow in focus

The technical assessment, carried out by consultants Hydrology and Risk Consulting (HARC), looked at how changing operating arrangements for Lake Eildon could protect downstream communities from future flooding.

During October 2022 the Goulburn River experienced major flooding, causing significant damage to farms, townships, roads, water supply infrastructure and communities.

HARC initially considered six options, suggested for their potential to improve protection for downstream communities from future flooding.

"All options explored were found to be ineffective or unreliable as flood mitigation strategies, or created costs and impacts that outweigh the benefits of a change to how the storage is managed," the HARC report said.

"The assessment report highlights that tributaries that flow into the Goulburn River downstream of Lake Eildon have a more significant impact on flooding in communities downstream, including Molesworth and Seymour, than releases from the lake."

The six options considered by HARC were changing the lake's target filling curve, reducing the amount of water in the storage, cutting levels back based on climate signals, increasing pre-releases based on forecast rainfall, changes to the maximum surcharge (where the water level is above the designed, or agreed, full supply level) or restricting maximum outflow.

HARC engineers found options three to six were "not robust ways to increase flood mitigation, provided by Lake Eildon".

A Deloitte report found the 2022 flood cost four councils, Mitchell, Moira, Murrindindi and Strathbogie, $432 million.

It found 132 properties were damaged, 552 kilometres of bridges, roads and trail walkways were affected and 2676 head of livestock were lost.

The impact also included the loss of 1801km of fencing, 55,762 hectares of broadacre cropping, pasture and horticulture and 23,830 tonnes of hay/silage and stored grain.

The area was also hit by floods, last year.

Goulburn River Trout co-owner Ed Meggitt, Alexandra, said the report was "extremely disappointing".

"It shows a lack of imagination and creative thinking, in finding ways to use Eildon to better mitigate flooding," he said.

"It feels as if the report was written to justify a desired, or known, conclusion: protect the status quo."

Mr Meggitt said another winter was approaching, with the lake sitting at more than 90 per cent capacity, and a La Nina was being predicted for spring.

"The operational status quo will lead to a full dam just as the heavy spring rains arrive," Mr Meggitt said.

"This policy doesn't mitigate flooding but perfectly sets us up for another dam release flood."

Yea beef producer Jan Beer said the report was what was expected from "water bureaucrats".

"They ignore the real stakeholders and decisions are constantly made by government agencies, people who have no 'skin in the game' and will never suffer the impacts of their decision making," he said.

"The report should be thrown out, in that it has failed to adapt to climate change with more intense, unpredictable events; it has failed to take into account the long-term economic loss to agriculture; it has failed to recognise the cost of environmental degradation created by major floods.

"It is a foolish, ignorant decision to maintain the status quo."

Beef producer and contractor Andrew Perry lives close to the base of the Lake Eildon dam wall, in the Whanregarwen-Molesworth area.

Local councils had been given "a reasonable amount of money" to conduct flood studies and the report would help inform that process, he said.

'What comes out of the flood studies then goes to the Water Minister, I believe, but I doubt there will be any changes - so we probably have to prepare our communities for similar floods," he said.

Lake Eildon was Victoria's greatest agricultural asset, particularly when it came to the irrigation area it supported, he said.

"But when its being managed with lack of flexibility in water harvesting, the associated floods that occur in wet years cost the state and the country a substantial amount of money," he said.

"More importantly they undermine the social and economic value of those affected communities."

He said as far he knew the study did not look at the cost of loss of production, over a longer timeframe.

"The other thing that didn't get considered was the cost to the environment of these floods, which I found quite disappointing considering the strong feeling all of the people living along the river have in relation to the damage that is being caused.

"They will have been given basic damage costs from Agriculture Victoria, but there was no advocacy for agriculture."

He said Victoria was in a "terrible financial situation", with agriculture representing $19 billion of gross domestic product.

"For its largest agricultural asset to be assessed, without any input from agriculture is a bit of a joke," he said.

Jock Blakeney manages properties between Alexandra and Molesworth and said it had been a "frustrating process".

He was hit hard during the October 2022 floods - "I spent seven days in a tinny, swimming cattle for people".

"There wasn't any consideration for any long-term damage to agriculture - we are still saying it is a four or five year recovery for pastures, from where we were," Mr Blakeney said.

"It didn't take into consideration environmental damage, the health of the river and restoration of that, or costing for that."

The report had a "very narrow focus".

"I didn't have any confidence, in any sections of it."