Heavy rain across the northern half of the island state began on Wednesday night and is not expected to ease until early on Friday morning.
Residents of an area stretching from Liena to Latrobe were on Thursday evening ordered to evacuate if safe to do so, with the region's Mersey River breaking its banks.
Those along the Meander River from Meander to Hadspen have also been told to leave their homes.
River peaks in some parts could reach levels seen in mid-2016 when flooding claimed the lives of three people and caused $180 million worth of damage.
Latrobe Council Mayor Peter Freshney said his community was anxious but better prepared.
"People and properties that experienced flooding in 2016 are most likely to experience that again," he said.
"We're preparing as best we can. (People) have their stock on higher ground, they are moving machinery to higher ground.
"We won't be hopefully rescuing people off rooftops - we'll be rescuing them before the event happens."
Five people and their animals were rescued from a property at Liffey, southwest of Launceston on Thursday.
The State Emergency Service has received 120 calls for assistance, with acting director Leon Smith warning rivers and tributaries will continue to rise overnight.
"There is still a large period of this event to go," he said.Â
"There's still a level of uncertainty in regards to the peaks. It's expected this situation will be protracted even once the rain stops."
The Great Lakes area in the state's central north topped the rainfall tally with 220 millimetres in a 24-hour window, while records were broken in several locations.
A severe weather warning was in place for the top half of the state, while eight rivers were subject to varying degrees of flood warnings.
Deputy Premier Michael Ferguson urged people to pay close attention to alerts and avoid unnecessary travel.
"Focusing on safety is our number one priority," he said.
"It is consistent with ... 2016 at this point in time. We're monitoring the situation very closely."
Several evacuation centres have been set up and many roads have been closed. The wild weather cut power to hundreds of people in the northwest.
Commercial operations at the port of Devonport have been suspended until Sunday, with the closure prompting the cancellation of four Bass Strait crossings by the Spirit of Tasmania ferry.