A section of Hempstead Road in Holt has been closed for emergency sewer repairs.
Anglian Water was alerted to a collapsed sewer under the road late last week and has asked for the road to be closed so work can be carried out safely.
The damaged pipe is more than 3.5m deep and so the closure could remain in place for up to three weeks.
A spokesman for Anglian Water said: “We are very sorry for the disruption this road closure and diversion will cause, but it is vital that we get the pipe repaired. If left, a collapsed sewer could lead to flooding and undermine the road so it’s important we get to work as quickly as possible.”
A 100m section of the road either side of Number 54 will be closed, with traffic diverted via Edgefield, Saxthorpe, Plumstead and Baconsthorpe.