Flood threat: Surge warning covers three tides
5 December 2013 Last updated at 16:38 GMT
Police are visiting 9,000 homes on the Norfolk coast as evacuation plans get under way in preparation for a predicted major tidal surge.
At a press conference, Supt Roger Wiltshire said severe flood warnings were in place.
Residents have been asked to leave their homes for up to 48 hours to cover three high tides expected to reach more than 6ft (1.8m) above a normal maximum.
Properties in Caister and Great Yarmouth are affected.