Since time immemorial, coastal areas of eastern England have been inundated repeatedly. Storm winds have raised sea levels and generated huge waves. Coastal defences have failed. Agricultural land has been flooded. People and their livestock have perished.

Along the coast of eastern England from the Humber to the Thames, there have been many failures of coastal defences.

In a storm in 1897, for example, 1.5 kilometres of the shingle spit at Orford Ness was washed away. Whilst in Thorpeness in 1911 an October storm washed Shorecote, now a pretty holiday house over the cliff. Fortunately damage was limited and the property was re-sited and today provides lovely holiday accommodation for ten people.

Surges are caused mainly by the action of wind on the surface of the sea, with barometric pressure a secondary factor. When pressure decreases sea level rises. Thus, a deep depression with a central pressure causes sea level to rise and when pressure is above average, sea level correspondingly falls.

The effect of a strong wind coupled with very low pressure can be to raise sea level in eastern England more than two metres. Fortunately, though, large positive surges tend to favour mid-tide. They rarely coincide with high water.

The strong winds that create surges also generate large waves. Embankments are usually high enough and other coastal defences sound enough to protect against all but the highest of surges. However, waves wash away protective dunes, and batter sea walls relentlessly, weakening them until they fail. They break over coastal defences, too, undermining the foundations on the landward side, until structural failure occurs.

The greatest surge on record for the North Sea as a whole occurred on 31 January and 1 February 1953. Almost 100,000 hectares of eastern England were flooded and 307 people died.

Surges travel counter-clockwise around the North Sea basin, first southwards down the western side of the basin, then northwards up the eastern side. They take about 24 hours to progress from north-east Scotland to south-west Norway.

In 1953, because many telephone lines in Lincolnshire and Norfolk had been brought down by the wind, virtually no warnings of the storm's severity were passed to counties farther south until it was too late. Suffolk and Essex suffered most. By midnight, Felixstowe, Harwich and Maldon had been flooded, with much loss of life.

Over the years, coastal defences in eastern England have been raised and strengthened continually to protect against storm surges. Our coasts and estuaries are safer now than they have ever been. Nevertheless, surges remain a threat, as complete protection against the most extreme can never be guaranteed. At least the likelihood of being taken by surprise is now rather low, because weather and surge forecasting systems have improved greatly in recent years, and the Storm Tide Forecasting Service has established clear and effective procedures for alerting the authorities when danger threatens.

(with acknowledgment to www.metoffice.gov.uk)