Australia Weather News

The Gawler River is flooding in some areas and is threatening the township of Gawler. - ABC

Flooding is underway in the town of Gawler and surrounding districts north of Adelaide as the Gawler River reaches its peak.

The State Emergency Service (SES) issued a flood emergency warning for the area, saying flooding is already occurring along stretches of the Gawler River.

It said suburbs that could be impacted included Gawler, Hillier, Gawler River, Angle Vale, Penfield Gardens, Two Wells, Lewiston, Virginia, Port Gawler and Buckland Park.

The SES worked with Australian Defence Force personnel to fortify riverbanks and levees, having already utilised about 30,000 sandbags.

At 10:00pm Friday it said the river had reached its peak and no homes or people were known to have been affected.

Waters were not expected to subside until early Saturday morning.

Gawler is the meeting point of the North and South Para Rivers, which form the Gawler River.

Those that live or work in the area have been advised to prepare their family and home for flooding.

"Move items of value to a safe place," the SES said.

"If your plan is to leave [and] if you require time to leave or if you are not prepared, you should consider leaving now."

Mayor Karen Redman said the local relief centre has been moved to higher ground at the Evanston Gardens Community Centre on Angle Vale Road.

"The rec centre or the sports and communities centre was used in the recent fires we had in the last couple of seasons and worked quite well, but it's in the one-in-100-year flood plain so that's not going to work if the river bursts its banks," she said.

The South Para River peeled away long sections of road overnight at a ford at the southern entrance to the town.

"That will take a few weeks to repair," Ms Redman said.

While no homes were known to have been inundated, the river also submerged parkland.

Ms Redman urged sight-seers who had descended on the town to inspect the high water levels to stay away.

The Bureau of Meteorology (BOM) said rainfall of 60 to 100 millimetres had been recorded across the Gawler catchment since Wednesday.

The Gawler Caravan Park also moved lower lying caravans near the North Para River to higher ground.

Flooding had also occurred further north-east of Gawler in the Barossa Valley.

Parts of the Barossa Valley were inundated with floodwaters after the North Para River broke its banks Thursday night, but water levels upstream in the North Para have since stabilised.

The rising floodwaters forced the late-night evacuation of campers at the caravan park in Tanunda.

State Emergency Service (SES) deputy chief officer Dermot Barry said there were also concerns about the Broughton River near Port Pirie.

Thousands of people across the state are also without power, including Port Lincoln, which has been without power since the state-wide on Wednesday night.

Port Wakefield Road reduced to one carriageway

The SES said there was an elevated flood risk for the township of Port Wakefield at the top of the Gulf of Saint Vincent.

It warned people living or travelling through the area to stay alert and monitor conditions.

High water levels in the Light River forced the closure of Port Wakefield Road's northbound carriageway.

Police said traffic, including the long weekend holiday traffic on Port Wakefield Road, would be restricted to one lane in both directions for 2.5 kilometres.

Flood warnings are in place for other areas including the Torrens, Onkaparinga, Angas, Bremer, Light and Wakefield rivers.

A flood watch also applies more generally for the Mid North, Mount Lofty Ranges and Adelaide metropolitan area, where falls up to 100 millimetres arepossible over the next few days.

The BOM said there was risk of further rapid rises in water levels and flooding in creeks in rivers across the watch area from Sunday through to Tuesday.

But the SES said floodwaters had begun stabilising in other areas including Clare, Lyndoch, Old Noarlunga, Port Noarlunga and the Gilbert River.

The service has also advised that the flood threat for Upper Waterfall Gully and Sturt Creek, and the threat from damaging winds on Kangaroo Island, have also reduced.

South Australia's rail infrastructure is feeling the impact of this week's storms.

The main rail line from Adelaide to Crystal Brook has been closed due to flooding, with the track potentially being closed for up to 24 hours.

The rail line between Two Wells and Mallala is being monitored for rising flood waters.

ABC