(adds British details, LONDON dateline)
AMSTERDAM/LONDON, Nov 8 (Reuters) - The North Sea coasts of the Netherlands and Britain faced their worst flood threat for decades on Thursday from a storm-driven tidal surge.
Authorities compared the approaching conditions to those in 1953 when floods killed more than 2,000 people in both countries.
The flood defences of the entire Dutch coast were put on alert and three surge barriers are expected to be closed as the storm approaches. The transport ministry said it was the first time since 1976 that the whole coast had been put on alert.
Shipping traffic to and from Rotterdam harbour is due to be suspended from 2000 GMT, a port spokesman said. The suspension is expected to remain in place until 1700 GMT on Friday.
For the first time since its construction in the 1990s, a storm surge barrier protecting Rotterdam and its harbour is expected to be closed due to the approaching storm.
Large areas of Britain’s Norfolk and Kent coasts are at risk of severe flooding, the government and environment agencies said.
“A tidal surge of up to three metres is making its way down the North Sea which could coincide with high tides,” Environment Secretary Hilary Benn told parliament.
A special meeting was being held by Prime Minister Gordon Brown to coordinate the emergency response, a spokeswoman said.
“There is a risk of flood defences being overtopped on the coast and in tidal rivers especially in East Anglia, particularly the Norfolk Broads, the coast south of Great Yarmouth, including Lowestoft, and areas south of this as far as the coast of Kent,” Benn said.
The Met Office said north-westerly winds exceeding 50 mph (80 kph) were coinciding with low pressure and high tides to produce the exceptional conditions. The Thames Barrier in London would be closed from 2000 GMT on Thursday, the agency said.
The floods in 1953 killed around 300 on the English east coast and more than 1,800 in the Netherlands. Two thirds of the Netherlands would have been permanently flooded but for an elaborate system of dikes and canals.
A Dutch transport ministry spokesman said the water level at the Hook of Holland was expected to rise to around 3 metres (9 ft 10 inches) above the mean sea level on Thursday night.
The level would be second only to the flood of 1953 when the water rose to 3.85 metres (12 ft 7 inches) above sea level.
“The storm conditions are very similar to 1953,” the ministry spokesman said. The government weather service forecast force seven winds for parts of the Dutch coast.
Rotterdam, a major transit point for oil, coal, grains and other commodities, handles about 35 percent of European port traffic by tonnage. About 60 ships will be affected by any closure of the port. (Reporting by Niclas Mika and Harro ten Wolde, Editing by Robert Woodward)