UPDATE noon Wednesday: Emergency services have located the truck that delivery driver Peter Watson was in when he was swept off Leighlands Road at Evandale on Tuesday morning.

Sergeant Tony Roughan said the Scottdale man's truck was located on Wednesday morning about 400 metres from where it was taken.

"As a result of the search and rescue efforts, we've sighted the van," he said.

"A winchman has gone down in very dangerous conditions and as far as we can tell, there is nobody inside the vehicle." 

Sergeant Roughan responded to the distress call on Leighlands Road on Tuesday morning and witnessed the truck being taken from the road.

"The water was moving very rapidly - the velocity of the water was really surprising."

The evidence of the flood's force was evident yesterday more of Leighlands Road was revealed.

Slabs of asphalt had been completely torn from the road as had several wooden posts that had been previously cemented deep into the ground.

- Matt Maloney

EARLIER: A Scottsdale man presumed drowned in floodwaters called his family from the roof of his van to say goodbye before being swept away on Tuesday morning.

Peter Watson, a 63-year-old contract delivery driver, and his partner Karen Cassidy were overcome by floodwaters while delivering Fairfax Tasmania newspapers at Evandale about 3am.

After the couple accidentally entered an inundated road, they climbed onto the roof of their partially submerged van.

It was there Peter asked his son Corey Watson to deliver a message to his family.

“He was scared,” Corey said.

“His biggest thing was to say how much he loved his family, his children Tanita Thynne, Natarsha Bett, Jessica Watson and Matthew Watson, and his stepchildren Claire Flice and Sean Cassidy.

“He said he’d watch over us always.”

About an hour later, he was gone – swept away by floodwaters before a helicopter could rescue the pair.

Ms Cassidy was found clinging to a tree branch about five kilometres downstream hours later.

Peter is yet to be found and police hold grave concerns.

“It was a tough search,” Tasmania Police Inspector Scott Flude said.

Emergency services will continue their search on Wednesday.

Ms Cassidy was treated for mild hypothermia and was kept under observation at the Launceston General Hospital for five hours.

She was released into her family’s care in a stable condition, a hospital spokeswoman said.

A Fairfax Media spokesman said the company’s thoughts were with Peter’s family.

"Our heartfelt thoughts are with the family and colleagues of Peter Watson, one of our contract delivery drivers, and his partner Karen, who were delivering newspapers for us when caught in floodwaters in Evandale near Launceston,” the spokesman said.

"We're relieved Karen is safe – however our deep concerns remain for Peter who is still missing. All our support and care is being offered during this truly difficult time."