Eight people have been rescued from rising waters as torrential thunderstorms continued to soak northern NSW, causing flash flooding.
Most of those stranded were people caught driving through floodwaters in the north and mid-north coast regions.
"It was a busy day for our crews in those areas," NSW State Emergency Service spokeswoman Sue Pritchard said on Wednesday, with at least 412 calls for help.
In Sawtell, just south of Coffs Harbour, a whopping 214mm of rain fell since 9am.
At least six properties were flooded in the town, while the roof of a hall at Coffs Harbour High School was also damaged.
Heavy falls were also recorded at Doon Doon near the Tweed River with 137mm, while Yamba received 126mm.
A severe weather warning for heavy rainfall remains in place for the Northern Rivers, Mid North Coast and parts of the Northern Tablelands, according to the Bureau of Meteorology.
"The persistence of the rain will keep adding to problems as it's not going to let up as we go further into the week," BoM forecaster Mohammed Nabi told AAP on Wednesday.
The low-pressure trough will mainly move along the state's northeast for the next few days, he said, adding that Sydney would be spared the worst of the storms.
The rainfall could cause flooding to develop on seven river systems in the state's north, and a minor flood warning has also been issued for Coffs Creek, the Brunswick River catchment, Marshalls Creek, Wilsons River and Orara River.
The SES has received more than 943 calls statewide since the wild weather began on Sunday, including nearly 300 from the western Sydney region where several four people were rescued on Tuesday.
Ms Pritchard said crews were keeping an eye on the wet weather in the state's north.
"We're definitely concerned, that area is quite wet and saturated already," she told AAP.
"The expectation is that we'll get more requests for assistance as that rain moves to mid north coast area," she said.
