Approximately 2,000 shacks and homes will be disconnected from electricity in South Australia's Riverland in the coming weeks.
SA Power Networks has confirmed more than 100 properties have been already switched off.
Up to 165 gigalitres a day is now expected to flow down the River Murray into South Australia from early December, putting an estimated 3,680 properties at risk.
Energy Minister Tom Koutsantonis gave South Australia's parliament an update Tuesday afternoon.
"As the flow rate rises ... it's expected that approximately 2,000 customers will need to be disconnected," Mr Koutsantonis said.
"SA Power Networks is providing customers with as much notice as possible, pending disconnection, typically a few days' notice.
"However, it's not possible in all circumstances to provide a notice."
Local councils will work with SA Power Networks in communicating with businesses, residents and agriculture groups to prepare landowners for the impact.
"Where disconnections occur, it can be expected the power will be off for weeks," Mr Koutsantonis said.
"These disconnections are highly undesirable for the local community, but they're done in their best interest.
"We know residents will be doing it tough in this part of South Australia."
Preparations underway
Last week, SES chief officer Chris Beattie said crews were planning for 160GL a day.
"At the 160GL mark we're now estimating that we'll see around 3,680 properties inundated above the floor level," he said.
He said that authorities were aware that it could be even higher than that estimate.
"I have to stress, these models have quite a number of assumptions built into them so they're indicative only," Mr Beattie said.
"We don't expect that to be an accurate figure — and as you'd expect, with heightened flows again, we'd anticipate even more properties to be subject to over-floor flooding.
"At the 200GL mark, we're looking at approximately 4,250 premises."
Those properties include shacks and other dwellings, farming and production facilities, industrial sheds, and community wastewater treatment facilities across low-lying areas of the Riverland.
"For permanent residents, if they've got flooding over their floorboard and the power is cut off, they will need to relocate," Mr Beattie said.
He said SA Health was working on an evacuation plan for the Renmark hospital and local aged care residents, and that vulnerable locals would likely be relocated if and when flows hit 130 gigalitres per day — an amount significantly below the highest forecasts.
