Thousands of southern Australian residents are under evacuation orders after days of rain pushed rivers and creeks to break their banks, inundating hundreds of homes in record-breaking floods.

Major flooding is occurring, or forecast to occur, on many rivers across Victoria, Tasmania and inland NSW, with a number of areas clocking up new flood records, the Bureau of Meteorology said this afternoon.

“Depending on what else we get over this potential wet spring and early summer, we could well be in a flood event for the rest of the year,” SES Victoria spokesman Jamie Devenish said.

At Maribyrnong, 10km from the Melbourne CBD, around 100 homes flooded this morning after SES volunteers and staff conducted a door knock in the area.

“Some of them chose to stay after the evacuation warning this morning and required the rescue boats to get them out,” Mr Devenish said.

Areas such as Victoria’s Goulburn River were “looking similar to the early 1970s, so record-breaking floods,” he said. Around 300 properties flooded and were isolated there, and Mr Devenish warned “that will have implications downstream”. Towns such as Benalla, Charlton and Murchison were urged to evacuate if it's safe to do so. Train and coach services were suspended to most regional destinations in Victoria.

The Insurance Council of Australia told insuranceNEWS.com.au it was unable to comment on claim numbers yet.

Victorian Premier Daniel Andrews said the event "will run for a number of days, we won't see peak levels of floodwater for quite a while”.

The Victorian government is offering around $2000 to eligible families, with 1500 applications already received for those emergency payments, and plans were underway to turn a quarantine facility built in response to covid into housing for those displaced by the floods.

"Even moderate rain events over the coming weeks will present a real challenge for us as well. So this is with us for a while yet,” the Premier said.

BOM issued major flooding alerts for Victoria’s Campaspe, Loddon, Ovens, Goulburn, Avoca, King, Broken and Maribyrnong rivers and Seven and Castles creeks, with warnings for anticipated major flooding on the Werribee, Yarra and Barwon rivers and Mt Emu Creek.

In Tasmania, record flood peaks are forecast along the Meander and Macquarie Rivers, while North Esk River at Corra Linn and Mersey River at Latrobe may peak around June 2016 levels, BOM says.

There is widespread significant flooding occurring across northern half of the state and extending into the Derwent catchment.

"Rivers are still rising as floodwaters move downstream through Friday and across the weekend,” BOM said.

Acting Premier Michael Ferguson said, while "hundreds" of homes across Tasmania have been evacuated due to flooding, significantly fewer residents have been using evacuation centres than during 2016 floods in the area.

"We rewrote the emergency response book and it's yielding dividends,” he said. Disaster support payments are available in 17 Tasmanian local government areas.

In NSW, around 250 properties are subject to evacuation or isolation orders in Forbes after the Lachlan River hit its major flooding mark on Friday morning. Wee Waa, Warren Town, Nanami, Jemalong and Barham are also being impacted by major flooding.

"Waterways are very sensitive to rainfall, and flooding is expected to continue for several months,” BOM said.