The State Emergency Service has urged people not to drive through floodwaters in the Hunter.
"A strong message we're trying to get out there is please don't drive, walk or ride through floodwaters," said Steven Lawrence, a spokesman for SES headquarters at Metford.
"You're putting your own life, volunteers and rescuers at risk. There's an awful lot of water on roads and some roads have been closed. A number of causeways have water over them."
Mr Lawrence said heavy downpours and strong winds had led to 185 requests for assistance in the Lower Hunter from midnight on Saturday to Sunday morning.
"Seventy-nine jobs have been completed, with 106 outstanding."
Requests for assistance included 44 in Newcastle City, 32 in Lake Macquarie, 19 in Swansea, 35 in Maitland and 19 at Tomaree.
Some of the worst-affected areas were Rutherford, Nelson Bay, Maitland, Adamstown, Raymond Terrace, Swansea, Gillieston Heights, Singleton and Wallsend.
The type of damage included leaking roofs and trees down on properties.
"Most of our jobs came early on Sunday morning when people woke up and realised the damage around fallen trees and leaking roofs," he said.
He said about 15 SES crews were in the field, while other emergency services were helping.
"We've still got a flood watch current for Wollombi Brook in the Lower Hunter," he said.
"A flood watch is a heads up for communities in those areas about the possibilities of flooding. There's been no river rises as yet, based on the weather predictions. But there's potential for some flooding in that Wollombi Brook and Lower Hunter area.
"We're just keeping a close eye on that and attending to those requests for assistance."