This morning Ms Golding said some places had already received upwards of 150 millimetres of rain in the past 24 hours.

"We are still seeing a steady stream of showers tracing into the central NSW coast," she said.

Ms Golding said the east coast low that had brought heavy rain and damaging winds had tracked across the coast overnight, but a coastal trough persisted.

However, she said there were signs the system would ease tomorrow - but shower activity would continue through the rest of the week.

Ms Golding warned that high winds were still affecting coastal and marine areas, and it was "quite dangerous" to go out on a boat today.

Read more:

Beyond the Illawarra, Menangle and North Richmond saw floodwaters peak close to the levels of last year's flood events.

Ms Golding said major flooding was expected at Windsor and Lower Portland this afternoon.

Emergency Services Minister Steph Cooke said about 30,000 people were subject to an evacuation warning or order - for some, it was the fourth flooding event in 18 months.

There were seven evacuation centres in the most high-risk areas, Ms Cooke said, and about 184 people had registered at them, with another 68 people in emergency accommodation.

SES Commissioner Carlene York again urged people to make safe and sensible decisions.

She said people should avoid any non-essential travel, with dangerous conditions on the roads.

Those who do have to drive should expect delays.

The Illawarra Mercury newsroom is funded by our readers. You can subscribe to support our journalism here.https://www.illawarramercury.com.au/subscribe