PART of an Exmoor road is in danger of collapsing after engineers discovered it was being undermined by a river, leading to urgent work which started on Monday (February 23).

Major engineering work is already underway to repair the A396 Cutcombe Hill where a school coach crashed last year, killing a 10-year-old pupil and injuring dozens more people.

Now, an inspection of the Pitt relief culvert further along the road near the turning for Snowdrop Valley has found an embankment has been undercut by the River Avill.

Senior bridge engineer team leader Nick Jacklin said the embankment and ‘a very large tree stump’ had been undercut to within a few inches of the highway.

Mr Jacklin said the river was now less than 10 feet below the road.

He said: “If allowed to continue unchecked, there is potential that we may lose a section of the A396, leading to great inconvenience of the travelling public, local businesses, and local residents.

“To pre-empt this, we have to design a retaining structure to keep the river from further encroachment on the highway.”

Mr Jacklin said a 65-foot stretch of the roadside was being cleared of vegetation on Monday to allow the required surveys, bore holes, and information gathering to go ahead.

He said: “We will also install temporary fencing to cover the area where the vegetation is removed.

“We have to carry this out before March 1 to avoid the bird nesting season which runs to August.

“These initial works will take place under two-way traffic lights during the day.

“We had considered carrying out the works at night under the closure for the Cutcombe Hill works, but due to the near vertical embankment the operation will be carried out using rope access techniques.

“It simply is not safe enough to carry this out in this environment using artificial light.”

Mr Jacklin said he did not have any estimate as to when the main repair work would take place, but the council was anxious to have it completed ‘as soon as practicably possible’.

He said: “Undoubtably, the main scheme will require a road closure, and we may have to have further traffic controls for some of the surveys.

“The inconvenience of this is surely outweighed by the possibility of having the road collapse and the extensive time and expense it would take to repair.”

Repairs to the section of A396 damaged in the coach crash are expected to be completed by the end of this week.

Contractors began the work on February 9 and have been working at night to minimise the disruption for local residents and for visitors during the Snowdrop Valley festival, which ended on Sunday.

Major engineering works were required with the use of king pin concrete anchors and a supporting concrete beam to ensure the long-term stability of the road.

Detailed ground investigations had shown that sheet piling would not be suitable for reinstating the verge edge and fencing.

The road has been under temporary two-way traffic lights during the day time.