Myall Road is now reopened to Westbound traffic, while Munnibung Road is closed in an easterly direction.

Hunter Water believes it will be a while yet before flooding at the intersection of Macquarie Road and Myall Road at Cardiff is drained.

The intersection is completely submerged in water, with one blue sedan stuck earlier this morning.

The issue was sparked when a 500mm pipe running underneath the roads ruptured around 5am.

Hunter Water spokesperson, Kieran Smith said some homes around the Munnibung Road area were left without running water or with low water pressure.

However, Mr Smith said, the burst main was isolated around 9am.

“We should find, given the pipe has been isolated now,” he said, “water should start to be restored as the system recharges.”

Lake Macquarie Police said there were indicators the road had been undermined and described the issue as “a major rupture.”

They expect the intersection to be closed for around 10 hours.

Diversions are still in place northbound and southbound, while buses are re-routing to avoid the area.

Macquarie and Myall Road, Cardiff. Image: Lake Macqurie Police.