With La Niña threatening to dump more rain on New South Wales, dam managers are releasing water to make space, but some farmers are warning that could cause "catastrophic" flooding downstream.
Others worry there will not be enough water in the system ahead of the next inevitable drought, so how do authorities manage the water in the dams?
All the state's major water supply dams are sitting above 90 per cent capacity, prompting water releases from Hume, Burrendong, and Copeton dams in the past week.
WaterNSW spokesperson Tony Webber said releases were necessary to increase storage for more rain.
"The fundamental aspect to our operations for the past 12 months where those dams have been high is that we don't release water to aggravate flood water downstream," he said.
"We make releases to generate storage capacity when we have some certainty around the weather forecast."
The primary role of dams is to ensure water security during times of drought, but where possible flood mitigation plans are applied to regional water storage.
Mr Webber said "huge volumes" of water had been released but dams could not intentionally be kept at low levels.
"We are operating these rules with the next week in mind but also with the next two or three years to consider," he said.
Deniliquin-based mixed farmer Louise Burge lives downstream from Hume Dam along the Murray River.
Her property has been flooded for the majority of 2022 and she said the Murray-Darling Basin Authority had "failed" to learn the lessons of the last La Niña weather pattern in 2016.
"They have left the decisions too late, which is exactly what happened in 2016, but this time the situation is far worse because you have already got rivers at low-level flooding," she said.
"One more rain event and we will go into catastrophic flooding."
Cowra crop farmer Chris Groves lives downstream from Wyangala Dam and says the authorities have got the balance between storage and releasing water correct.
"Credit where credit is due; state water have done a very good job," he said.
"We have had the Lachlan River running up to the tops of the banks, they haven't caused any minor flooding but they have certainly been shifting a lot of water."
Lessons from last drought
Following the 2016 La Niña pattern, NSW experienced one of the worst droughts on record between 2017 and early 2020.
Mr Webber said this experience was an important consideration when managing dam water levels.
"It is difficult to remember the intensity of the drought and what a crisis our water supply was placed under by the almost absence of water flows into the dams," he said.
"These dams serve to provide water security for all water users in these regions when the inevitability of drought becomes a reality."
Ms Burge said during seasons of heavy rainfall, the priority for dam management should shift from water security to flood prevention.
"Yes, you have to conserve water for times of drought, but you can't make major decisions on dam storages when they are already full and you are facing La Niña conditions," she said.
"The next drought could be 10, seven or five years away, we have got to deal with the here and now."
However, Ms Groves said the drought following 2016 showed the importance of keeping dams full.
"Going into a drought you want your water storages 100-per-cent full because that means you have continued production for a longer time," she said.
"We had a full dam at the start of 2017, then it didn't seem to rain again until February 2020."
