Officials have closed a busy village ford after a man in his 70s died while crossing, saying it is "unsafe".
Shotesham Ford, where the Tas crosses Mill Lane on the edge of the village, will not reopen until at least January 3.
Norfolk County Council has issued an 'emergency notice' to close the road - from the junction with the A140 to a point 0.8m away on the other side of the river.
The notice says that heavy flooding in the area - which has swelled the river and increased the water levels significantly - has made conditions on the crossing unsafe.
The order is dated Friday, December 15 - the day after the body of a man was found when his car crashed in the fast-moving water - although it gives a start date for the closure of December 12.
Police are still investigating the man's death but he is understood to have got into difficulties while attempting to cross the ford on Wednesday evening.
Officers have appealed for anyone who might have seen the vehicle, a red Toyota Yaris, travelling between Trowse and Shotesham St Mary on that night.
The closure order say that 21 have been provided for the ford to drain but warns that "exceptional circumstances" may see it closed for longer.
It provides an alternative route, via Norwich Road, Cargate Lane and the A140 Ipswich Road.
Motorists who continue to try to cross at the ford face a fine of up to £1,000.
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Anyone with information about last week's accident is asked to contact Norfolk Police on 101 quoting incident number 547 of December 13.
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