Man stranded as road turns to river in Whanganui

A farmer has filmed what he describes as a frightening experience when he was trapped by a flash flood.

Dan Steele and his dog were caught by floodwaters above a river on his high-country farm in Owhango in the central North Island.

He owns Blue Duck Station, just north of Whanganui National Park, and was left stranded with nowhere to go.

More than 120 millimetres of rain fell over the weekend, with half of that coming in just one hour on Saturday night.

"The flood is just about to carry my truck away, but it just burst out of the valley down here in 30 seconds, and as you can see it's just smashed through the rails and the fences and broken over the roads," Dan said in the video.

His father, Richard, says recently replaced culverts are the culprits.

"They just totally blocked. They're still blocked up. We had our own digger in there and can't unblock."

That meant the water poured down Dobbs Bluff instead of running into the river, blocking in Dan.

"It goes up 55 metres above the road and 50 metres below the road. You are always at a danger of being swept off," Richard said.

But thankfully for Dan, his brother Richie was just down the road, charging upstream.

Dan and Buck Rogers are both fine, thanks to a timely tractor trip.