HEAVY RAIN feeding a number of hidden springs appeared responsible for the break up of nearly 1km of road in East Anglia last week.
Norfolk County Council said flooding lifted the surface of Marshgate Road in North Walsham, causing cracking along an 800m section.
'Our consultant, SDS Drainage Services, is still investigating' said a Norfolk spokesman.
'It has already found a number of unknown drainage chambers and hidden springs'.
These had probably surfaced because of recent heavy rain.
The road is to be temporarily resurfaced, but a permanent solution awaits the consultant's report.