Heavy rain has already inundated some homes and brought trees down, with motorists rescued after driving into floodwaters at Albion Park.

Up to 300 millimetres of rain is predicted to fall, mainly along the Illawarra Escarpment, and damaging winds up to 90km/h will lash the region from Friday, April 5 to Saturday.

"If this comes, this will be the sixth time [of flooding] since 2010," Albion Park Rail resident Leonie Whitton said.

"They have predicted 300mm and it'll come through our house. I'm scared because sometimes it's in the night and you can't see. "

The Princes Highway home owner said during heavy rain water rushes from the industrial park (which includes Bunnings and Sydney Tools) located behind her property and into her house.

"Ever since the industrial area has come it's been worse," Mr Whitton said

The couple were among residents rushing to sandbag their homes in preparation for the predicted downpour.

Multiple sandbag points have been established across the Illawarra, and people are bagging up sand as quick as SES volunteers can replenish supplies.

Jemma Nicholls' home business on Coachwood Drive in Albion Park has flooded multiple times in the past, and on Friday she rushed to collect sandbags from Albion Park Showground.

"My house floods every single time," she said. "I have to lift everything up because of the floods."

Her business Little Gremlins Co, which stocks items for babies, toddlers and parents, lost $17,000 in stock during a previous flood.

"Water just washed half my stuff away," Ms Nicholls.

"We have a huge stormwater drain that floods, even when it's not heavy."

Albion Park Hotel has sandbagged and tarped its entrance doors in preparation for the wild weather.

A hotel spokesman said there's a low-lying area that gets inundated with floodwaters each time there's heavy rain.

Bring your own shovel. Sandbags are available from:

If sandbags are no longer available, bring your own empty heavy-duty garbage/grocery bags, pillowcases, grain bags, or coffee bean hessian sacks to fill up with sand.