Residents in the central Victorian town of Muroopna, which neighbors Shepparton, were also told it was too late to leave due to floodwaters expected to inundate homes on Saturday night and Sunday morning.
The Midland Highway, the main road connecting the two towns, was closed Saturday night.
Water levels on the Goulburn River were expected to exceed the main flood stage of 11 meters overnight and could reach 12 meters on Tuesday. In the flood of 1974, the height of the river reached 12.09 m.
River levels in Rochester peaked at midnight Friday, but were not expected to drop significantly until Monday.
“They are on very flat areas, so it takes time for the water to wash away [away] and for the river level to drop,” said Bureau of Meteorology senior hydrologist Yves Bessard.
Residents of Echuca have been told to stay away from their homes for up to 10 days as two swollen rivers burst into the border town.
“When we’re talking about towns near the Murray River, we can see major flooding that lasts for a week, and that’s because the river level is very high,” Bessard said.
In addition to Campaspe bringing flooding to Echuca over the weekend, the Murray will also rise in the middle of next week as water enters the system from the Mita Mita, Owens and King rivers.
“Imagine that the water coming down the Campaspe River would meet the Murray, and that would prevent water from being washed down the Murray River,” Bessard said.
“Water in the Murray rises very slowly, but it also falls very slowly.”
The SES’s Wiebusch said it was a “fragile situation” in Echuca, which last experienced major flooding in 1993.
“You should be aware of your conditions and prepare to evacuate, especially if you are in areas some distance from the river,” he said.
“Don’t expect that just because you’re a kilometer or two away that it doesn’t affect you.”
With major regional cities on alert, Victoria Police Assistant Commissioner David Clayton also urged people to heed the advice of emergency services before it was too late.
“We expect to see some of the largest evacuations we’ve ever seen in the coming days, so please heed these warnings and evacuate when asked,” he said.
More than 4,000 properties could be inundated in Shepparton, where a large-scale sand collection operation was underway on Saturday.
A line of cars gathered at the Shepparton Showgrounds to collect a maximum of 25 bags, which were produced by a machine flown in from Sydney capable of producing 1,000 bags every hour.
Shepparton resident Lisa Costigan said she did not believe the 25-bag limit would be enough to save her home if the water level got high enough.
“Hell no,” she said. “Depending on where the water is coming from, it will only cover one side of the house, but I’m not sure what else I can do.”
Residents in the town of Murchison, north of Seymour, were also urged to evacuate on Saturday as the Goulburn River threatened to reach 11.9 metres, just below the record of 12.22 metres.
Charlton, in the west of the state, was under an evacuation order as the Avoca River neared flood levels last seen in 2010-2011.
Electricity suppliers Powercor and CitiPower say they may be forced to shut down substations in Charlton and Muroopna due to flooding.
“If a significant amount of floodwater reaches any of the substations, it could be a serious safety hazard, so we may need to de-energize them to protect the community and reduce the risk of long-term infrastructure damage,” the spokeswoman said.
Several roads were closed on Saturday, including the Goulburn Valley Highway, Midland Highway, Northern Highway and Calder Highway.
Portions of McIvor Highway in Oakdale, south of Rochester, were washed away and left a crumpled mass of asphalt and dirt after Campaspe made landfall.
The federal and state governments have agreed to use those who have recently retired A $580 million quarantine facility in Mickleham as emergency housing.
The Victorian Government has confirmed the facility will reopen for 250 people early next week and crisis accommodation will be available for six to eight weeks, but its actual use will depend on demand.
A massive clean-up has begun in Melbourne after the Maribyrnong River receded and people were able to properly inspect their mud-covered homes.
Piles of damaged household items, furniture and clothing piled up on footpaths along Auckland Street, one of the worst-hit streets.
Residents used brooms and rakes to clear ankle-deep mud from their driveways and gardens.
A total of 245 homes in the inner northwest suburb were flooded on Friday, the SES said, well above the 60 initially predicted.
With Benjamin Price, Adam Carey, Marta Pascual Juanola and Liam Mannix