ENGINEERS are drawing up plans for the intricate rebuilding of one of Exmoor's best known beauty spots - the iconic Tarr Steps bridge - after it became the latest casualty of the 2012 weather.

More than half the landmark clapper bridge that links Dulverton and Withypool was washed away when heavy rainfall turned the River Barle into a raging torrent, with water levels ten feet deeper than normal.

The force of the swollen river sent uprooted trees and debris crashing into the structure and even damaged wire 'booms' upstream of the bridge, specifically designed to catch floating trees in extreme conditions.

The 50-metre bridge - the longest of its kind in Britain - is a scheduled ancient monument and is also grade one listed.

It is made up of sandstone slabs weighing between one and two tons apiece and although once thought to be prehistoric it is now widely believed to be of medieval origin.

A spokesman for Somerset County Council, which is responsible for the bridge as a public highway, said this week it was not the first time it had been damaged by floods.

Its English Heritage listing confirms previous incidents including 1942, 1952 and 1979 and in the past some of the 17 slabs that are laid end to end have washed up 50 metres downstream.

The county council spokesman said the main stones of the bridge had been numbered following previous flood damage to enable the stonework to be recovered and put back together in the right order.

But he admitted rebuilding the structure would be a challenge.

"Recovering and rebuilding the heavy and odd-shaped stones in the river is not easy and repairs to a scheduled monument such as this require special approval," said the spokesman.

"Floating debris and trees crashing into the bridge caused much of the damage.

"Our engineers are currently planning the repairs and the Exmoor National Park Authority will be checking the river banks for material that might become dislodged and be carried away in further flood conditions."

National park conservation manager Rob Wilson-North said he had been shocked to see the damage.

"It was the speed of the water, it was absolutely terrifying," he said.

"It was moving so fast. I've worked on Exmoor for 20 years and I've never seen it like that."

Sightseers have been warned to keep their distance for safety's sake.

"In these difficult conditions we would always appeal to the public not to place themselves in danger by using any bridge that may appear to have been damaged by, or at risk from, flood water and floating debris," said the county council spokesman.

The damage happened as nearby Dulverton suffered its worst floods for 30 years, leaving a string of homes and businesses under water as the River Barle burst its banks at the lower end of the town.

Photos: Chris Sampson