The prime minister has urged people along the east coast to monitor rising water levels, as the tidal surge proves to be less extreme than first thought.
Gordon Brown has chaired two meetings of the emergency response committee Cobra since the Environment Agency issued a warning of "extreme danger to life and property" in areas across Norfolk and Suffolk.
As the prime minister chaired the second meeting at 6am this morning it emerged the tidal surge was likely to be around 20 cm less than first expected.
The Environment Agency and Met Office had warned yesterday of a 3 metre (9.5ft) tidal surge along the East Anglian coast.
Hundreds of residents in Great Yarmouth have been evacuated and eight severe flood warnings are now in place, along with 12 flood warnings and 23 flood watch areas.
Speaking to reporters this morning, Mr Brown said: "Our first priority is to ensure people are safe, and that's why over the course of yesterday and throughout the night we have been bringing in the helicopters, the sandbags, the preparations that are absolutely necessary so that people are safe.
"National government stands ready to help local communities with any difficulties that arise."
Mr Brown said it was "too early" to assess the damage that has been done.
Officials have denied suggestions they over-reacted to the expected surge. Mr Brown agreed: "I think it very important we make preparations when given warnings by the Environment Agency and Met Office.
"In the course of the next few hours, the important thing is that we continue to monitor the situation locally and through the Met Office."
Tides are still at their highest level for 50 years along the east coast and parts of Great Yarmouth have flooded.
The surge passed Lowestoft at 9am this morning and coastal areas further south are still on alert.
One railway services has suspended services between Lowestoft and Norfolk due to flooding and Felixstowe docks have been shut.
The environment secretary Hilary Benn has appealed for calm.
He told Sky News "I know many people will be anxious about their homes and their property and what's going to happen but I think everything that can be done to prepare has been done.
"We've just now got to wait and see what nature produces".
In 1953 more than 300 people died when large parts of Lincolnshire, Norfolk, Suffolk, Essex and Kent flooded after a 3.2 m tidal surge.