Authorities in far west New South Wales are preparing to stop releases of water into the lower Darling River, cutting off flows to the region for the second time in three years.
WaterNSW will likely close the gates to Menindee's Weir 32 within a week, to conserve the drinking water supply for Menindee and Broken Hill being held in the Menindee Lakes.
The agency has conceded that cutting off releases from the lakes into the lower Darling could result in further fish deaths.
Citrus growers along the lower Darling have already watched the river stop flowing twice in recent years, and temporary block banks have again been constructed to allow landholders access to pools for stock and domestic use.
Alan Whyte from Jamesville Station on the river said he had been expecting the move.
"We have access to water from one of the block banks, and realistically the majority of properties will have access to the block banks, but not everyone will," Mr Whyte said.
"So there will be some properties running out of water in the next week, or two, or three."
WaterNSW was going to shut the gates on Tuesday, but postponed it to work with fisheries managers on a plan to guard against further fish kills.
"[Fisheries authorities] are … looking at what type of options they've got at the moment, to advise us as to what we can do to mitigate the risk once the flows actually cease," Mr Langdon said.
"So we're probably going to postpone it for three or four days while they finish their work."
For lower Darling growers, it is the fourth time since 2003 the river has stopped flowing.
"The river had been running continuously before then back to 1943," Mr Whyte said.
"Everyone — state and federal — has got to start treating the river as the highest priority.
"This mess was preventable."
Focus on town supplies
Drinking water for Menindee and Broken Hill is sourced from the Menindee Lakes system.
The last major intake of water for the lakes was in winter 2016.
"It's actually balancing the need of the Menindee community with the needs of the lower Darling community," Mr Langdon said.
"We've still got around about 19 gigalitres behind the main weir in Lake Wetherell.
"We expect that that supply there should be able to maintain the local community through to spring without any further inflows."
A 270-kilometre pipeline from the Murray River to Broken Hill is almost ready to be switched on.
Once that happens, Broken Hill will no longer be reliant on water from the Darling River system.
Fish still struggling at weir
After three major fish kills at the Menindee Lakes, there were no signs that conditions for the remaining fish were improving.
Menindee local Graeme McCrabb said there were more than a dozen cod, perch and brim struggling to breathe in the pool below Weir 32 on Wednesday.
"There's potentially 17 to 20 that will … die this week," he said.
"There's two or three that just keep rolling belly-up.
"They are breaking the water, their back is out of the water."
Another donated aerator was due to arrive at Menindee yesterday, but Mr McCrabb said it was difficult to know whether the fish had a better chance where they were or being moved to another pool.
"Myself personally, if one died by my hands if I tried to save it, I don't think I'd handle that very well emotionally to be honest," he said.
