AUSGRID has warned it is on standby to shut off the power supply to Singleton if conditions worsen.

With potential evacuation warnings in place, Ausgrid has advised the community to be prepared for the power supply to be turned off at short notice.

"Power supply may need to be shut off as flood waters on live electrical assets can pose significant community safety risks," it said in a statement.

"Please ensure your devices are charged and follow the instructions of the SES and emergency responders.

"Remember, there are no second chances with electricity. Fallen powerlines may be hidden by flood waters.

"Proceed with caution and always assume a fallen wire is live, stay at least eight metres away and call Ausgrid on 13 13 88."

It comes as the New England Highway has been closed to light vehicles in both directions at Singleton.

Motorists travelling southbound are being diverted at White Avenue and can use Blaxland Avenue and Bridgeman Road to Obanvale.

From there, drivers can use Retreat Road, Dyrring Road and Gresford Road to join Queen Street at Singleton.

Vehicles travelling northbound are being diverted at Pitt Street and can use John Street to travel to Queen Street and Gresford Road.

From there, they can use Dyrring road and Retreat Road to join Bridgman Road at Obanvale.

For more updates visit Live Traffic NSW.

Ausgrid will continue to provide updates through its websites, social media pages and SMS.

All registered life support customers are being urged to enact their Plan B.

Members of the community should switch off power points and unplug devices and appliances from the wall if their property has not been flooded.

If the property has been impacted by water, it is not recommended to approach the main switchboard as it can cause a shock under fault conditions if touched.

UPDATE Wednesday, 10.30am:

Evacuation orders are in place for the Bulga, Broke, Combo, Whittingham, Scotts Flat, Glennriding and Dunolly areas.

An evacuation warning is in place for the Singleton township.

What the SES is expecting

Moderate flooding is occurring at Singleton, with major flooding likely.

What you need to do

For emergency help in floods and storms, call the NSW State Emergency Service on 132 500. In life-threatening situations call triple zero (000) immediately.

Wednesday, 9am:

The NSW State Emergency Service has issued an evacuation warning for the Singleton township.

The warning calls for residents to monitor the evolving flooding situation and to be prepared to evacuate if instructed to do so.

"A Flood Evacuation Order will be issued by the NSW SES if and when evacuations are required," Hunter NSW SES advised on Wednesday morning.

The evacuation warning comes as the Bureau of Meteorology predicts increased flooding along the Hunter River for the Singleton area, exceeding the major flood levels experienced in March 2022.

"As a result, residents and visitors to these areas should take action now to prepare for possible flood impacts," Hunter NSW SES said.

"NSW SES is advising residents in low lying areas of the following locations that they may need to evacuation due to rising flood water."

Where to go if evacuation is required

Wherever possible, people should go and stay with family or friends, or make other accommodation arrangements.

An evacuation centre has been set up at Singleton Diggers, Dorsman Drive, Singleton Heights.

Evacuation with COVID

If you are currently in self-isolation due to COVID-19, contact the Public Health Unit on 1300 066 055 before leaving your location, where possible.

What Hunter SES is expecting

Once floodwater begins inundating the area, road access may be cut. If you remain in the area after this time, you may become trapped and it may be too dangerous for NSW SES to rescue you.

What you need to do in preparation for evacuation

Earlier Wednesday, 8.30am:

Singleton's Mayor has reached out to the community during the area's major weather event. You can read it here.

The SES have described the flooding in Wollombi Brook as the highest since 1952.

And the expected water level for the Hunter River at Singleton this afternoon will exceed those recorded in March this year of 13.40m. In November 2021 the river reached 12.3m.

Bridgman Road is closed northbound traffic trying to access Singleton Heights, Hunterview and rural areas beyond Bridgman Road should use the alternate route.

Access starts at Boundary Street, followed by Queen Street, Dyrring Road, Retreat Road and then onto Bridgman Road.

Heavy rainfall since Sunday morning has caused river level rises across the Hunter River catchment.

Significant river level rises have been observed along Wollombi Brook, where major flooding is occurring above March 2022 flood levels at Wollombi and Bulga.

River level rises are expected to continue during Wednesday morning and levels at Bulga may reach 8.40 metres, with major flooding. This is the highest recorded level since 1952. Further rises possible, with forecast rainfall.

Along the Lower Hunter River at Singleton, moderate flooding likely from Wednesday morning, with major flooding possible at Singleton from Wednesday afternoon.

River levels are expected to exceed March 2022 flood levels from late Wednesday afternoon and may reach 13.60 metres. Further rises possible, with forecast rainfall.

Minor flooding and renewed rises are occurring at Maitland, with moderate flooding possible from Wednesday afternoon.

Further rainfall is forecast for Wednesday, which may cause further river level rises and prolonged flooding. This situation is being closely monitored, and revised predictions will be provided as necessary.

Major flooding is occurring along the Wollombi Brook.

The Wollombi Brook at Wollombi may reach around 14.40 metres early Wednesday morning, with major flooding. Further rises possible, with forecast rainfall.

The Wollombi Brook at Bulga is currently at 8.13 metres and rising, with major flooding (above March 2022 and March 2021 levels). The Wollombi Brook at Bulga may reach around 8.50 metres early Wednesday morning, with major flooding. Further rises possible, with forecast rainfall.

Minor flooding is occurring along the Lower Hunter River at Singleton and Maitland. Major flooding is likely at Singleton. Moderate flooding is possible at Maitland.

The Hunter River at Singleton is likely to reach the moderate flood level (11.50m) early Wednesday morning. The river level is likely to exceed the major flood level (13.00m) Wednesday afternoon and may reach around 13.60 metres Wednesday evening, with major flooding. Further rises possible, with forecast rainfall.

From Singleton Council: Crews are inspecting the local road network this morning and the following roads, causeways and bridges are currently closed due to flash flooding.

Please note the Singleton Disaster Dashboard does not seem to be updating. Please note the below road closures:

Due to the current flooding event, Rose Point Park, Cook Park, Civic Park and Allan Bull Reserve and Skate Park are now closed until further notice. All sporting fields are also closed.

Due to the weather event and impacts on availability of staff, the following Council facilities will be closed from Wednesday, until further notice: