MORE than half of Shane Barber's 768ha Glenorchy property has been under water since Saturday night.

But he is confident his 200ha of crops, including canola, will be "fine" if the water drains off quickly and providing rain forecast for this week holds off.

"We've had a lot of floods but nothing this size. It was just astronomical and quick," Mr Barber said.

"When the river was rising you could be sitting there talking to someone and in five minutes it would rise like three inches (75mm)."

He said some of his friends had lost stock but they couldn't gauge numbers due to restricted access to paddocks.

Lubeck farmer Ian Taylor was looking at a bumper spring harvest last week.

This week he faces losing up to half his 2800ha of crops.

Mr Taylor's property flooded on Monday as water flowed down from Glenorchy.

"There's another 20 or 30mm forecast here for (today) I think and that is going to really put us under the pump."