The 1953 North Sea flood was a major flood caused by a heavy storm that occurred on the night of Saturday, 31 January 1953 and morning of Sunday, 1 February 1953. The floods struck the Netherlands, Belgium, England and Scotland.
A combination of a high spring tide and a severe European windstorm over the North Sea caused a storm tide; the combination of wind, high tide, and low pressure led to a water level of more than 5.6 metres (18.4 ft) above mean sea level in some locations. The flood and waves overwhelmed sea defences and caused extensive flooding. The Netherlands, a country with 20% of its territory below mean sea level and 50% less than 1 metre (3.3 ft) above sea level and which relies heavily on sea defences, was worst affected, recording 1,836 deaths and widespread property damage. Most of the casualties occurred in the southern province of Zeeland. In England, 307 people were killed in the counties of Lincolnshire, Norfolk, Suffolk and Essex. Nineteen were killed in Scotland. Twenty-eight people were killed in West Flanders, Belgium.
In addition, more than 230 deaths occurred on water craft along Northern European coasts as well as on ships in deeper waters of the North Sea. The ferry MV Princess Victoria was lost at sea in the North Channel east of Belfast with 133 fatalities, and many fishing trawlers sank.
Realising that such infrequent events could recur, the Netherlands particularly, and the United Kingdom carried out major studies on strengthening of coastal defences. The Netherlands developed the Delta Works, an extensive system of dams and storm surge barriers. The UK constructed storm surge barriers on the River Thames below London and on the River Hull where it meets the Humber estuary.