Residents have been warned to watch the weather and tides
Prime Minister Gordon Brown was chairing an emergency Cobra meeting, as low pressure and strong winds combined to cause a North Sea tidal surge.
Norfolk and Suffolk have seven severe flood warnings. Parts of Kent, Essex, North Yorks and Lincs are on alert.
The Dartford Creek and Thames barriers were set to be closed at 2000 GMT.
The flood alerts are a response to weather and tide patterns being tracked this week by the Environment Agency and the Met Office.