The Bureau of Meteorology said the main flood peak is now approaching Denman where river levels are expected to peak near 8.90 metres around 09:00 am Saturday, with moderate flooding.

The Bureau issued a major flood warning for Singleton for Saturday evening, with the Hunter River expected to exceed the minor flood level of 10 metres in the town at around midday on Saturday.

"Flood waters from the Upper Hunter will combine with large inflows from the Goulburn River and Wybong Creek," the Bureau said.

"These flood flows are expected to cause moderate and possibly major flooding to develop at Singleton during Saturday afternoon into Sunday."

The Bureau said the river level at Singleton is likely to exceed the moderate flood level (11.50 m) early Saturday evening and may reach the major flood level (13.00 m) overnight Saturday into Sunday, with further rises possible.

A moderate flood warning for Maitland was also issued by the Bureau for Sunday.

Meanwhile river levels have receded below the minor flood level in Scone and Aberdeen after flooding occurred on Friday.

77 homes were evacuated by Upper Hunter Shire Council on Friday due to rising flood waters on the Kingdon Ponds in Scone.

Flash flooding also occurred in the Upper Hunter towns of Murrurundi and Cassilis.