Residents in parts of both Seymour and Yea in central Victoria have been told to evacuate due to rising floodwaters as the state responds to heavy rain.
Flooding is expected to affect a number of streets in Seymour, where the river level is expected to surpass the 1993 flood level.
The Seymour warning said flooding was expected to impact some streets around the river between the Hume Freeway and the Goulburn Valley highway.
The warning issued shortly before midday on Monday told residents if they did not evacuate those areas before 6pm "your property may be isolated or inundated with water and it may be too late to leave".
The Yea warning was issued at 12.45pm and said flooding was expected to hit properties near the river including those that back onto part of the Riverside caravan park.
That warning asked residents in those streets to evacuate immediately if it is safe to do so.
It comes amid widespread heavy rain across Victoria which has seen much of the state inundated and on alert for flash flooding.
A severe thunderstorm warning from the Bureau of Meteorology is current for a section of Victoria stretching from Melbourne's outer-north-east to Wodonga and across to the state's far east.
Emergency crews and water police carried out 26 flood rescues across the state overnight, including 11 in Bendigo.
The State Emergency Service (SES) has received hundreds of calls for help, many for damage to homes.
SES Assistant Chief Officer Mark Cattell said a number of homes were inundated by flash flooding.
"We've got a lot of crews across the state currently preparing for the impending weather, we've also got a lot of crews that are resting after a very busy night in the Bendigo area," he told ABC News Breakfast.
An emergency relief centre has been set up at the Bendigo Showgrounds for anyone affected by flooding.
The City of Greater Bendigo and the SES are working to potentially relocate about 30 families in Goornong, north-east of Bendigo.
Flood water from Bendigo will flow through to Rochester via the Campaspe River.
The area is still recovering from floods which lashed the state more than a year ago.
But authorities in the area are urging calm, promising there will be resources to assist, with the town unlikely to see anywhere near the flood level seen in October 2022.
At a midday meeting, Judith Gledhill from Rochester SES said a moderate flood level was expected, similar to the November 2010 flood, where no Rochester properties were impacted.
But the SES is preparing for a flood level of 114-115 metres above sea level, which could threaten six homes.
Heavy rain hits much of Victoria
Heavy rain has also been falling in the state's north, with six-hourly falls of up to 100 millimetres in some areas.
Heathcote, in Central Victoria, recorded 160 millimetres of rain in 24 hours.
Flash flooding is likely in places like Shepparton, Wangaratta and Wodonga.
Meteorologist Miriam Bradbury said the effects of the heavy rain were being felt in many parts of the state.
"The rainfall around Bendigo triggered some flash flooding which moved downstream overnight and has triggered a major flood warning for the Campaspe River," she told ABC News Breakfast.
"It's an ongoing, unfolding situation as that rain continues to fall today."
There are flood watches in place for rivers in Gippsland and in Central and Northern Victoria, in addition to the major flood warning for the Campaspe River.
A major flood warning has also been issued for the Goulburn River.
The Mallee, Northern Country and Wimmera forecast districts were also battered by strong winds and hail stones overnight.
Melbourne Airport says more than 70 flights have been cancelled, mostly due to the weather.
Warning not to drive into floodwater
The SES said there had been 920 calls for assistance in the 24 hours to 10am Monday morning. That number included more than 500 calls related to flooding and 118 counts of building damage.
SES duty officer Aaron White reminded people in areas affected by flash flooding not to make poor choices.
"We really tell the community to stay well clear of any dangerous circumstances. That includes driving into floodwater - it may be the last decision you ever make, you don't know what's under those floodwaters," he said.
The SES rescued a man who had driven into floodwater at Lilydale, north-east of Melbourne overnight.
SES Lilydale Unit Controller Shaun Caulfield said vehicles could get into trouble in as little as 15 centimetres of water.
"Luckily for this driver, this water was not particularly fast moving so he was just bobbling along in his car but we had to go and get him out," he told ABC Radio Melbourne.
"He was quite distraught actually at not knowing how deep that water actually was."
Bendigo residents deal with flood damage
Craig Wicks has lived in Huntly, in Bendigo's north, for more than 20 years.
His sheds have flooded for the third time in two weeks.
"We're forever getting flooded out. It's through my sheds, through my front yard and there's three or four houses here that could get flooded," he said.
He said he had been calling for council to improve drainage for four years.
"They have to start doing something about it. Enough is enough," he said.
Darwin couple Bryan and Catherine Miles are staying with family in Bendigo and said it was a rough night.
"We were sleeping in the garage, we had the kayak in the shed ready to go, just in case we needed to use it to get to the house in the morning," Mr Miles said.
The SES says the flood threat in Bendigo has reduced but residents along the Campaspe River from Lake Eppalock to Barnadown have been advised to move to higher ground.
Regional centres in clean up mode
SES crews in south-west Victoria responded to about 70 calls yesterday after more than 70 millimetres of rain fell around Warrnambool.
Steph Landy was playing outside with her children when flash flooding hit her property.
"It was like a river going down the front [of the house]," she said.
A brick wall in the backyard of her property collapsed during the flash flooding.
In Kerang, in Victoria's north earlier today, residents were reporting water backing up through their toilets and showers.
Resident Adam Ridley said he was desperately trying to keep the inside of his home clean.
"[I'm] reaching out to different people in different parts of town and they are saying the same thing: they're having issues with their toilet.
"It's so frustrating."
- This story was first published by the ABC.