South Australia's State Emergency Service (SES) says engineers are working to repair more than 50 levee banks along the River Murray ahead of the flood peak which is now expected from Boxing Day in Renmark.
One major levee burst has already left the town of Ponde isolated, as the key lines of defence throughout the region is tested by rising floodwaters.
SES Chief Officer, Chris Beattie, said about one levee a day was breaking or breaching along the river — mostly private or agricultural levees.
"We've got about eight levees that have had catastrophic failures, so they've been breached in their entirety and can't be repaired, about 53 levees where there are serious defects which we're getting engineers to have a look," Mr Beattie said.
"We're actively working on a number of very large structures including at Cobdogla".
He said work to assess and repair several levees was underway, including at Renmark's hospital levee, where seeping had been seen behind the wall.
"The engineers assessed that to be likely groundwater, it's quite salty, and again not a structural concern with the levee itself," he said.
"At this stage the government has zero concerns about the integrity of the levee and it won't affect our operational plans ... in terms of the operation of the hospital and the planned relocation of residents as the river rises."
Premier Peter Malinauskas said there was confidence that the flood peak would reach Renmark around Boxing Day. "It could be a little bit earlier, it could be a little bit later but that's the key day that we will be keeping a close eye on the peak coming through Renmark."
Ponde residents feeling the impact
Further down the river, residents in Ponde are having to make alternative road arrangements after a levee in the area broke, inundating roads and sending water rushing towards the Riverland community it was protecting.
Ponde resident Rosie Schellen said her property was normally about a kilometre away from the river.
"[The river is] now only about 500 metres away, and it's just slowly creeping up, so we expect by the end of tomorrow for it to be 40 or 50 metres away," Ms Schellen told ABC Radio Adelaide.
"We're up on a little bit of higher ground, so our property is not impacted in itself, but the roads are all shut off so it's more now just trying to work out access in and out.
"We're working with the neighbours at the moment ... who have been amazing, just working out and cutting fences [to go cross-country]. It's a little bit of a worry because up the top it's a little bit sandy."
Ms Schellen said they knew the water was coming and had been slowly preparing for inundation, but the levee bursting "had just hurried things along" for her family.
"It has been quite an anxious time with the uncertainty in flow rates and heights but [we were] anticipating it overflowing the levee at some stage," she said.
"My grandparents weathered the 1956 flood and the property has been within the family for three generations, so we had a bit of an idea where the water levels would impact."
Ms Schellen said she hoped her property would not end up isolated, but with her front paddock and road already inundated, she is now only able to travel using a four-wheel drive.
For now, it is impending power cuts that are posing the biggest issue for Ms Schellen and her family.
Tree fall led to levee breach
Mid Murray Council Mayor Simone Bailey said a resident heard a "big crash of a tree falling" at about 6.30am on Sunday, which led to the levee breach.
She said the levee, which has been in the community for some time, was being monitored by authorities before the breach.
"I do know this one was being checked on, but when a tree falls in the wrong place, this is what happens," she told ABC Radio Adelaide.
On Sunday, the SES said residents of Ponde should prepare to isolate due to the breach.
SES chief of staff Graeme Wynwood said crews would be out to assess the damage today, but believed no-one had been left stranded.
"[The levee] had what we would call a 'catastrophic failure' so a big chunk of it basically fell apart and washed away, and allowed water to escape," Mr Wynwood said.
There was also a levee breach at Murrawong, almost 20 kilometres south of Ponde.
A watch and act warning is in place for residents there.
Mr Wynwood urged people in the areas of the breaches to avoid the levees and the water.
"Once a levee breaches, water rushes out, as you can imagine it gushes out from a high point to a low point at quite fast velocities and significant volume so people need to be careful around those, keep away from the levees and keep away from the water," he said.
Community 'feeling positive'
Mid Murray Council Mayor Simone Bailey said she went on a tour of a number of communities in her council area with South Australia's Governor General Frances Adamson at the weekend.
She said people were feeling positive despite the situation.
"We're just seeing so much resilience, so much teamwork, collaboration, everyone working together to ensure the vulnerable are being looked after which is just really heartwarming," she said.
"A lot of people said they found it really hard to step into the relief centre and ask for help, but once they did they were really satisfied with the service they received, so it was really good hearing people are getting the support they need."
Ms Schellen said it had been a similar situation in Ponde, with residents helping each other out.
"All the family and neighbours came out to help sandbag everyone's houses," she said.
"It's amazing how the community comes together when times are tough. It renews your faith in human kindness."
