Emergency services have carried out more than 100 rooftop rescues at Eugowra in Central West NSW, and thousands more have been rescued or evacuated as flash flooding swept across large parts of Victoria and western NSW on Sunday night.
The NSW State Emergency Service (SES) said it had 11 helicopters working on flood rescue operations in the town alone.
Eugowra has one of the 16 emergency orders in place in New South Wales, urging people to evacuate or move to higher ground.
Thunderstorms caused more than 100 millimetres of rain to fall across parts of New South Wales and more than 60mm in areas of Victoria in the past 24 hours to Monday morning, leading to more than 1,000 calls for help to NSW and Victorian State Emergency Services.
Some of the highest falls were in the already flooded NSW town of Forbes, which received 118mm — the community's heaviest rain since records there began in 1875.
The Lachlan River at Forbes is expected to peak near record levels late on Thursday, according to the Bureau of Meteorology.
Residents have been told to evacuate before 9am Tuesday ahead of renewed flooding.
Major flooding is already occurring further downstream at Condobolin with further rises possible from Tuesday.
Bathurst has been cut in two as the Macquarie River breached the town's levee, flooding the Great Western Highway.
Residents in the NSW towns of Molong and Eugowra were told to move to higher ground last night as evacuation was considered too dangerous, after the communities were cut off by floodwaters.
An Australian Defence Force (ADF) night-time winching helicopter was dispatched to Molong to rescue people trapped in floodwater or needing medical help.
Fire and Rescue NSW (FRNSW) said its crews helped to rescue people stranded in roof-high floodwaters, including a couple from the top floor of a motel.
FRNSW said the floodwater was so strong it smashed shop windows and knocked out the back wall of a supermarket.
The NSW Rural Fire Service said it had rescued people clinging to trees and others from rooftops.
Molong resident Jill Englert said she was woken at 2am by the sound of howling winds and pouring rain.
"It was just torrential, bucketing down, it was amazing," Ms Englert said.
"The recreation ground is a swimming pool and the railway lines are all under."
The NSW SES said substantial flash flooding was also occurring in Eugowra in the state's Central West, where 100 people were rescued from their roofs.
"We've sent additional assets in regards to rescue helicopters and seeing what other options we have available in terms of road access," Greg Nash from the NSW SES said.
"But we really want the public to avoid the area, to listen to the warnings, and if they are in the area, if it's safe to do so, to move to higher ground."
In Victoria, a freight train derailed at Inverleigh, west of Geelong, where 34mm of rain fell yesterday.
People in Mount Martha, Mornington, Hastings, and Dromana were told to stay indoors on Sunday night, due to the risk of flash flooding.
Residents of Beaufort and Lexton, north-west of Ballarat, have also been warned to stay indoors because of flash flooding.
Some other communities along the Kiewa River, Tallangatta Creek, the Mitta Mitta River, and on the Murray River downstream from Hume Dam have been advised to move to higher ground.
The Murray River at Albury and Wodonga hit major flood levels overnight after Albury received 85mm of rain in the 48 hours to 9am on Monday.
An evacuation order remains in place for south Albury residents as water levels continue to rise with more rain predicted.
SES commander Curtis Kishere said the Murray River had reached 5.5 metres in town — exceeding major flood levels.
"We have not seen a flood like this for nearly 50 years," he said.
Mr Kishere said SES volunteers had responded to 65 call-outs for assistance over the 48 hours to 6am on Monday, including one flood rescue last night.
He said the rescue occurred after four kids playing outside the drain of the local botanical gardens climbed the fence and fell in. He said all of them were safe.
Wyangala Dam spilling at record rate
In New South Wales, significant inflows into the Wyangala Dam on the Lachlan River are causing it to spill at a record rate of 230,000 megalitres a day.
That is well above flows of up to 125,000ML seen earlier this month, ahead of near record flooding downstream at Forbes, and more than the previous record of 205,000ML set in 1990.
Water NSW said in the first 11 days of November, even before yesterday's rain event, more than a third of the dam's capacity had already flowed into it.
"The upstream catchment is saturated, so inflows from the last rain event are still running in when you're trying to make space in the dam ready for the next rain event," spokesperson Tony Webber said.
"In normal circumstances that next rain event might be three or four weeks away.
"Well, increasingly and acutely so in September and October, the next rain event is three or four days away, so it really is a challenging time for Wyangala."
Rivers to rise, snow on the way as storms ease
Rain was forecast to ease today as the weather system shifted to the Tasman Sea according to the Bureau of Meteorology's hazard preparedness and response manager, Steven Bernasconi.
But he said temperatures for inland New South Wales would drop by up to 10 degrees Celsius below average on Tuesday.
"It seems strange to be talking about this given that we're talking about flooding, but we are potentially looking at snow forecast to develop on the Alps on Tuesday, with snow getting down to levels around 900 to 1,100 metres overnight," Mr Bernasconi said.
"There may even be a dusting of snow around the Central Tablelands come Wednesday."
A high-pressure system will restore generally benign weather through the middle of the week, with another rain-bearing system expected to arrive this weekend.
However, some river levels will continue to rise throughout the week, as floodwaters make their way downstream.
The Macquarie River in Bathurst is expected to reach 7 metres at some time on Monday.
And on the Murray River, major flooding higher than the 1975 flood may occur at Boundary Bend, Euston, Mildura, and Wentworth.
Flood safety advice:
In life-threatening emergencies, call triple zero immediately. If you require rescue, assistance to evacuate, or other emergency help, ring NSW and VIC SES on 132 500.
- Avoid drowning. Stay out of rising water, seek refuge in the highest available place
- Prevent damage to your vehicle. Move it under cover, away from areas likely to flood
- Avoid being swept away. Stay out of fast-flowing creeks and storm drains
- Never drive, ride, or walk through floodwater. Floodwater can be deceptive and dangerous
- For more emergency information, advice, and access to the latest river heights and rainfall observations and forecasts:
* NSW SES: www.ses.nsw.gov.au
* VIC SES: www.emergency.vic.gov.au
* RMS Live Traffic: www.livetraffic.com
* Latest river heights, warnings, and rainfall forecasts: http://www.bom.gov.au/
* BOM NSW Twitter: www.twitter.com/BOM_NSW
