Warnings for record-breaking flooding expected for NSW, Victorian towns including Forbes, Wagga Wagga

The Central West NSW town is among 22 locations in the state with an emergency warning, others include: Cowra, Wagga Wagga, Tumut, Bourke, Gunnedah Mathoura and areas around Moama.

In Victoria, there are emergency warnings for Euchua and Koondrook Public School.

NSW SES Forbes Unit Commander, Inspector Roc Walshaw urged residents to look after themselves "be safe, stay out of floodwater".

"There's lots of pesticides, faeces and all that sort of rubbish is floating in the water. Plus, there's snakes, wildlife, dead animals as well," he said.

The Forbes Iron Bridge river gauge is expected to reach 10.8 metres on Friday. The last time it reached that mark was June 1952.

The river is expected to stay above major flood levels for at least a week.

An evacuation centre is open at Forbes High School.

NSW SES Assistant Commissioner Nicole Hogan urged people in flood-affected areas to have a plan on where to go and how to leave.

"Gathering items in your home such as medication, appropriate clothing, waterproof bags for your valuables and a torch can help you while you evacuate," she said.

"We are also asking people to have a plan for any domestic pets, and ensure they are able to be restrained and contained as you move around."

IN OTHER NEWS

Residents inside the North Wagga Wagga levee and Gumly Gumly in the state's Riverina were advised to evacuate by Thursday evening and parts of North Gunnedah have been evacuated.

At 4pm on Friday, 22 flood warnings remained in place by the Bureau of Meteorology for NSW and ACT.

People are urged to obey road closure signs and not to drive, walk, ride through, play or swim in flood water, and avoid storm drains and pipes, ditches, ravines, creeks, and rivers.

At 4pm on Friday, emergency flood warnings remained in place for Echua and Koondrook Primary School.

There are 18 weather warnings across the state, with minor to major flooding expected along the Murray and Edward Rivers.

Historic flood levels are predicted for Euston, Boundary Bend, Mildura and Wentworth in coming weeks, with water expected to rise higher than the 1975 flood event.

Residents of: Albury, Corowa, Yarrawonga, Tocumwal, Echuca, Moama, Torrumbarry, Barham, Swan Hill, Wakool Junction, Boundary Bend, Deniliquin, Stevens Weir, Moulamein, Mildura and Wentworth have been put on alert.

Large breakout flows from Torrumbarry spilling into the Wakool River, combining with flows from the Murray and Edward Rivers, are likely to cause major flooding at Wakool Junction from over the weekend.

Meanwhile, Victoria SES, the Environment Protection Agency (EPA) and Natural Hazards Research Australia have begun work on characterising contamination issues in the state's continuing flood emergency.

Floodwater can be toxic after becoming polluted with overflowing sewerage or septic tanks, or agricultural or industrial wastes and chemicals.

Victoria SES chief officer Tim Wiebusch said the results will provide critical information for emergency services to inform the community about floodwater risks.

"At VICSES safety drives our decisions, and we continue to emphasise to never walk, drive, or play in flood waters," he said.

More flooding across eastern Australia is expected over the spring-summer season due to increased rainfall forecast into 2023.

The forecast is based on two climate drivers; a La Nina system and a natural climate phenomenon that influences weather patterns around the Indian Ocean, known as Indian Ocean Dipole.