Eastern Victoria and southern NSW were bracing for further rain on Friday after some areas recorded more than 150mm of rain in a day.
Kameruka Estate near Bega copped 200mm in 24 hours to Thursday evening, while Mallacoota over the Victorian border - where a landslide cut off the town on Thursday morning - recorded 112mm.
Floodwater blocked a road and covered paddocks in Heyfield, Victoria. (Diego Fedele/AAP PHOTOS)
Mallacoota remained cut off to the public as of midday Friday, however, emergency vehicles were still able to access the town.
The rain thinned out on Friday but floodwaters continued to threaten communities including the Bemm River, which was expected to be cut off the town when the river flooded.
The Bureau of Meteorology earlier warned rain would continue to fall on waterlogged areas throughout Friday and into the weekend.
Parts of eastern Victoria were likely to record total falls of 200mm.
There were 527 calls for assistance in the 24 hours to 4am on Friday and 10 active flood warnings in place in Victoria.
Major alerts were in place along the Thomson and Avon rivers as of Friday afternoon.
WATCH & ACT - RIVERINE FLOOD - Move to Higher Ground - Buchan River— VicEmergency (@vicemergency) Act now - take actions immediately to protect your life and property, and move to higher ground.More details at https://t.co/fItCqhS24K pic.twitter.com/uJApMSqGwRDecember 1, 2023
Moderate flood warnings were in place for the Buchan, Macalister, Snowy and Mitchell rivers.
An alert for the Bemm River was downgraded to advice-level with river levels easing for Friday and into the weekend, but emergency services warned renewed rises were possible with forecast rainfall.
"The community of Bemm River is very much likely to be cut off this afternoon as the floodwaters make their way down Bemm River catchment," East Gippsland Shire Mayor Tom Crook told ABC News.
There were four separate landslips on the sole road into Mallacoota and only emergency vehicles are able to get in or out, Victoria's State Emergency Service told AAP.
Debris was expected to be cleared by Friday afternoon, with the town effectively cut off until then.
"I've never seen so much water in our water system in the 40 years I've lived here," SES volunteer Jenny Lloyd told ABC TV.
The town was severely affected during the Black Summer bushfires in 2019-20 and there are fears this bout of rain could fuel new growth and cause further risks for the coming fire season.
"This is the price we pay for living in a little piece of paradise," Ms Lloyd said.
Several advice-level flood warnings were in place for NSW, with parts of the state's southeast expected to record up to 300mm by the end of Friday.
A severe weather warning for heavy rain for people in parts of the south coast and Snowy Mountains remained in place on Thursday night before conditions were expected to ease.
The bureau warned flooding could persist after rain subsided in NSW and Victoria.
There is also a risk of severe thunderstorms in central, southern and southeast Queensland on Friday, while severe heatwave conditions persist in the north.
29°C