On Sunday, the river burst its banks in some areas and threatened to breach the levee around the town of Maitland, prompting the evacuation of as many as 6,000 people.
Phil Campbell, the state Emergency Service spokesman, said around 400 houses were still at risk of being flooded swept away by the swollen Hunter which peaked at 10.7 meters above its normal height late on Sunday.
Around 1,000 people remained in evacuation shelters Monday, he said.
"Those people will have to wait a bit longer until conditions improve for them to be able to return home,'' he added.
Newcastle, Sydney and the Central Coast region were hammered by the storms which struck on Friday and continued over the weekend, leaving behind a trail of destruction.
|A coal freighter was beached by |
the storm on friday [Reuters]
Among those killed were five people from the same family who died when their car plunged into a swollen creek after the road collapsed beneath them.
Another man drowned after he was swept into a storm drain while getting out of his car on a flooded road.
The storm also swept a 40,000-ton coal freighter onto a sand bank near Newcastle, raising fears of an environmental disaster if the ship's fuel oil began to leak.
On Monday salvage officials reported finding a puncture in the vessel's hull, but no sign that the internal fuel tanks had been damaged.
The ship was not carrying any cargo when it ran aground and none of the 21 Filipino crew, who were later taken off the ship, were injured.
Meanwhile, efforts to reconnect some 40,000 homes to the electricity grid four days after power was disrupted by the storm were hampered by damaged roads.
Anthony O'Brien, spokesman for EnergyAustralia, said they had to "rebuild and restring entire lines because the poles have just collapsed".