FLOOD experts are ready to spring into action along the Thames this coming weekend as the highest tides for many months are expected.

The authorities are preparing to close the flood gates at Dartford, the Thames Barrier at Woolwich and minor waterways leading into the river.

"It is too early to make predictions at this stage," said Dean Smith, flood warning officer for the Environment Agency. "We will issue warnings to the public and other authorities if there is a risk."

The agency is especially concerned about the effect that bad weather in the North Sea could have.

The river is expected to be seven metres above normal at Gravesend on Friday afternoon. But this is only a guide. The main risk is from a surge.

High winds from the north or north east can push millions of tons of North Sea water towards the Kent shore.

More than 300 people were drowned, including 68 at Canvey Island, on the night of January 31 1953. A low atmospheric depression and high winds caused a surge, which swept water down into the Narrows between Margate and the Continent on a spring high tide.

On the Continent, 1,800 drowned when the sea defences were breached. On that night the Sheerness guide was just below three metres. At its peak on Friday the forecast level is 3.23 metres.

Mr Smith said: "Since the 1953 inundation there have been various improvements put in place. The defences between Gravesend and Dartford and between Queenborough and Sheerness are pretty well the best in Kent. If there was going to be any impact it would be in the rural areas along the flood plain."