Upper Goulburn River producers endure their third flood in less than 12 months

They say silage paddocks and infrastructure on the river flats from Thornton to Yea have again been damaged, at a cost of tens of thousands of dollars.

Floods occurred in October last year, again in May and then earlier this month from the extreme weather system that crossed Victoria.

In April, Goulburn River Trout, Alexandra, director Ed Meggitt told Water Minister Harriet Shing and Goulburn-Murray Water, landholders were seeking urgent changes to the Lake Eildon operating rules.

He said landholders "dodged a bullet" earlier this month, as Lake Eildon stood at 96pc capacity on the first of the month.

It was fortunate there was enough airspace in the lake to catch the 140,000 megalitres of flood water from the rain event between October 3 and 4, he said.

"To have the lake at 96 pc was not a management decision by GMW - it was just good luck," Mr Meggitt said.

"All year they have stood by the status quo infill curve, which would have put us at 99.7pc on October 1.

"If it had not been for the dry September, and the 100,000ML environmental flow that went out of the lake that month, we would could have seen a very different outcome."

He said if the lake was full, GMW would have released 60,000-80,000ML a day.

"This would have caused catastrophic flooding all the way down the Goulburn Valley - we have dodged a massive bullet."

"It is clear from what has unfolded over the last 12 months that a new full supply level must be adopted for Lake Eildon to protect communities in the Goulburn Valley," Mr Meggitt said.

"There are many billions of dollars of agricultural assets and other infrastructure in the Goulburn Valley that underpins our community - they need protecting."

Agricultural contractor Andrew Perry, Molesworth, said GMW was again looking at ensuring Lake Eildon was again 100pc full, due to the El Nino declaration.

"We are imploring the Water Minister to intervene again, to revisit the 100pc fill, which is what they are resetting to now," he said.

"If we get a 40-60mm thunderstorm event, we will flood again."

Mr Perry said much of the pasture on the river flats between Thornton and Yea that was re-established after the last flood, again went under water.

He knew of one property where 120 hectares of pastures had been destroyed in the latest flood.

"A portion of the reestablishment came about through state and federal flood recovery funding - a very large amount was spent by individual businesses," he said.

"The percentage of loss of pastures will be significant - the will to resow, with the Lake at 100pc, is not there and you can't blame anyone for that."

Producers were caught out by inaccurate rainfall forecasts, and unreliable assurances from GMW, he said.

Mr Perry said the area was not listed in the flood watch when the event unfolded, resulting in a scramble to get stock to higher ground.

"The June flood had an impact on 20-30pc of the pastures resown from the October event," he said

"We are only at the early stages of working out how bad it is - the water is only just starting to recede."

Whanregarwen Pastoral Company director Andrew Seamer, Molesworth, said GMW released "a lot of water" in June, which again inundated pasture resown to oats, rye and clover for silage after October's flood event.

"By keeping Lake Eildon as full as they do, they really just don't have anywhere to go," the beef producer said

"So when you get a good rainfall they do need to release as much as they do.

"It is opportunistic management by the water authority, trying to maximise their return - they are in the business of selling water, so why let it go for free?" Mr Seamer said.

About 20 hectares of his pastures on Wanregarwhen Road, Molesworth, were still under water,

"First, we'd cleaned it up, we had killed all the weeds, fertilised, put down new seed and it was getting ready for silage again - it's inconvenient, to say the least," he said.

He said the contrast with paddocks on the Yea River, which also flooded in early October, was stark.

"We had about 60 hectares go under, but the water dropped and went away in two or three days - I look at that and say that's because there is no-one upriver, releasing water.

"That's a natural event and we live with that, the other one is being interfered with, on the Goulburn."

He estimated it would cost about $40-50,000 to resow "depending on whether you can get the fertiliser, the cost of your machinery, the cost of seed and labour - and also cleaning up.

"A lot of stuff comes down the river and you find yourself spending a week to 10 days moving logs, picking up stuff, just so you can get around the paddock."

He said he felt "it doesn't have to be this way.

"I look at some of our neighbours and they are really under the pump, they are stressed, they are spent," he said.

GMW Incident Controller Shayne Lowe said Lake Eildon was managed to a framework set out by the Victorian Water Act 1989.

The Act seeks to protect the reliability of water entitlements while offering some flood mitigation where possible.

"GMW is required to set target filling points so that Lake Eildon will reach full capacity with inflows that would be expected in 95 years out of 100 (i.e. it would only not fill in very dry years)," Mr Lowe said.

"These targets are formally reviewed and updated at the start of each month but are continuously monitored and can be adjusted depending on catchment conditions, forecast inflows and expected demands.

"This allows GMW to adapt its operations to help mitigate the impact of rain events such as the one in early October 2023."

He said GMW began increasing releases from Lake Eildon on September 28, when it was first forecast that there could be significant rainfall in the following days, creating more room for inflows.

"While it is understandable that the current focus is on the risk of floods, our storages must also be managed with the knowledge that droughts are an unavoidable part of our climate," he said.

"The water we are able to store now will be crucial when the next dry period arrives, so we must be careful not to release water in anticipation of rainfall events that do not eventuate.

"The Department of Energy, Environment and Climate Action (DEECA) is conducting an assessment of the operating arrangements of Lake Eildon. GMW is fully supportive of this assessment and will provide information where relevant."