More rain on the way has the potential to flood already soaked areas of Adelaide's outer suburbs as river levels are closely watched.
Around 10-20mm of rain is expected to fall on Sunday evening around the Gawler River catchment, which remains at a moderate flood level.
The river had already broken its banks in a number of areas by Sunday morning, but water levels are receding, SA State Emergency Service chief officer Chris Beattie says.
"We're confident it won't actually exceed its channel; it will start to drop away, and then come up as we get the rains come through again," he said.
Crews are stationed at Gawler and Virginia, north of Adelaide, monitoring the situation and helping residents prepare their properties with sandbags.
Some residents had been evacuated from the area, but the level of damage to houses in the area would take some time to work out, an SES spokesperson told AAP on Sunday.
There have been numerous rescues over the weekend with people trapped in floodwaters.
Three people were thrown out of their rubber dinghy in fast-moving waters in Flinders Park on Saturday.
Four flood rescues involving cars also occurred as drivers attempted to drive through flooded roads, the SES said.
Mr Beattie called the actions "misadventerous" and "foolhardy".
"It's very hard to maintain control in standing in moderately shallow flowing water and so people can get into trouble very quickly," he said.
The Bureau of Meteorology has called the weather pattern a one-in-20 years flood event in South Australia.
Areas including Mount Lofty Ranges and the mid north, already affected by last week's cyclonic storm that led to the entire state losing electricity, have also been told to prepare for another soaking.
Monday and Tuesday could bring more than 100mm of rain to parts of the area.
"With the weather coming, that just maintains the risk level," Mr Beattie said.
He warned people to be extra vigilant when returning to flooded homes with contaminants including sewage likely to be in the water.
Mr Beattie also advised residents to ensure they called a licensed electrician to check the full electrical works of their property if water levels had risen above the floorboard.
With water levels receding, numerous roads reopened on Sunday, including Port Wakefield Road and Balaklava Road in Port Wakefield.
