Water levels at Renmark have reached their peak, the South Australia's SES says, while they have warned a shack community in Murraylands to "shelter in place" because key roads are closed.
SES's Sara Pulford says they believe Renmark has reached peak water levels.
"We have crews out regularly monitoring those critical levees so we're confident that we've got good intelligence coming in every day on this," Ms Pulford said.
"Obviously that will take some time to make its way down the river, two to three weeks before that peak gets down to the far end around Wellington."
Ms Pulford said most of the levees in Renmark have been holding up, and evacuation orders have been issued for the areas where levees have breached in the past few weeks.
"Nobody can deny we're in a sort of a watch and wait situation now," Ms Pulford said.
"The planning is in place, everybody's worked really hard to make sure that everything that we could do to mitigate the effects of these waters has been done."
But she warned the Riverland community to be aware of changing situations and read warnings thoroughly about what to do when floodwaters reach their area.
On Saturday, the state government said flows to South Australia across the NSW-Victoria border were looking closer to be at the low range of predictions at 190 gigalitres per day, reaching Renmark on Boxing Day or early on Tuesday.
Road collapses near Bolto
The SA State Emergency Service (SES) issued a flood emergency warning for the Bolto shack community across the River Murray from Mannum, saying it is unsafe to evacuate.
Rising flood waters have significantly damaged and shut down Hunter Road near Haythorpe Reserve, isolating the community.
Ben Haythorpe, who lives in Cowirra near Bolto, said a section of Hunter Road collapsed on Christmas Eve, sending floodwaters into his property.
"I think there's not going to be a lot of dry land left," Mr Haythorpe said.
"This part here is actually lower than the river, so we're expecting the water will come in and hang around for a long time and might take a long time to go away after the river reaches its peak.
"The peak here in Mannum is still about two weeks away so there will be a lot of water for a long time."
He said flood preparation for his property has been in place for months.
"We've had a lot of helpers come up and help clear out our farm and make sure everything's safe and secure," Mr Haythorpe said.
"I guess we're lucky because we've had a lot of chances to prepare, we had a lot of notice ... but still it's pretty heartbreaking."
This is not the first time Mr Haythorpe had to move out of his Bolto family home, which was last flooded in 1974.
"We can't live in the house, there's no electricity there, no sewerage so [we] have to move out, but we'll be back and we will be rebuilding," Mr Haythorpe said.
The SES have warned the Bolto residents that they can no longer leave via Hunter Road.
"It is now unsafe to evacuate the area," the SES said.
"A total road closure will be in place by the end of [Sunday] as it is expected that a section of Hunter Road will be completely washed away." the SES said.
The SES urges people in the Bolto shack community to follow their emergency plan, notify family and friends of the plans, move to the top floor or higher ground, and avoid travelling on roads unless absolutely necessary.
Renmark prepared from 1956 flood experience
Ian King was home at Mundic Creek near Paringa when the water levels were expected to peak at Renmark.
He was amazed at how much it had changed in just a few days, but said the peak is likely to impact other Riverland towns more than it has tested Renmark.
"In Renmark, anyone that's going to be flooded has already flooded," Mr King said.
"Here we've been fairly lucky, we've got good levees around the place and council's been excellent with its work.
"Some of them [the levees at other Riverland towns] aren't quite as good, Renmark has always been prepared from the '56 flood.
"Even though their levees weren't terribly well maintained, they were still in place, so it didn't take an awful lot to get them back up into shape."
