The North Sea flood of 1953 (Dutch: Watersnoodramp: 'the flood disaster') and the associated storm combined to create a major natural disaster which affected the coastlines of the Netherlands and England on the night of 31 January – 1 February 1953. Belgium, Denmark and France were also affected by flooding and storm damage.
A combination of a high spring tide and a severe European windstorm caused a storm tide. In combination with a tidal surge of the North Sea the water level locally exceeded 5.6 metres above mean sea level. The flood and waves overwhelmed sea defences and caused extensive flooding.
Officially, 1,835 people were killed in the Netherlands, mostly in the south-western province of Zeeland. 307 were killed in the United Kingdom, in the counties of Lincolnshire, Norfolk, Suffolk and Essex. 28 were killed in West Flanders, Belgium.
Further loss of life exceeding 230 occurred on watercraft along Northern European coasts as well as 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.
On the night of 31 January – 1 February 1953 many dykes in the provinces of Zeeland, Zuid-Holland and Noord-Brabant proved unable to resist the combination of spring tide and a northwesterly storm. On both the islands and the mainland large areas of country were completely flooded with water. Many people still commemorate the dead on 1 February.
At the time of the disaster, none of the local radio stations broadcast at night, and many of the smaller weather stations operated only during the day, as a result of which the warnings of the KNMI did not penetrate the flood-threatened area in time. People did not receive warning and were consequently unable to prepare for the impending flood. Telephone and telegraph networks were disrupted, and within hours amateur radio operators went in to the affected areas with their home-made radio equipment to form a voluntary emergency radio network. These well-organised radio amateurs worked tirelessly, providing radio communications for ten days and nights, and were the only people maintaining contact with the outside world. In addition, the disaster struck on a Saturday night, and many offices in the disaster area were unstaffed.
The floods put large parts of Zuid-Holland, Zeeland and Noord-Brabant under water. In Noord-Holland only one polder was flooded. The largest floodings occurred on the islands of Schouwen-Duiveland, Tholen, Sint Philipsland, Goeree-Overflakkee, the Hoeksche Waard, Voorne-Putten and Alblasserwaard. Parts of the islands of Zuid-Beveland, Noord-Beveland, IJsselmonde, Pernis, Rozenburg, Walcheren and Land van Altena were flooded, as well as parts of the areas around Willemstad, Nieuw-Vossemeer and parts of Zeeuws-Vlaanderen. The heaviest death toll was recorded at the islands of Schouwen-Duiveland and Goeree-Overflakkee. The government started the Delta-commission to study the causes and effects of the floods. They estimated that flooding killed 1,835 people and forced the emergency evacuation of 70,000 more. Floods covered 9% of Dutch farmland, and sea water inundated 1,365 km² of land. An estimated 30,000 animals drowned, and 47,300 buildings were damaged of which 10,000 were destroyed. Total damage is estimateed at 1 billion Dutch guilders (250 million Euro).
The Schielandse Hoge Zeedijk dyke along the river Hollandse IJssel was all that protected three million people in the provinces of South and Noord Holland from flooding. A section of this dyke, known as the Groenendijk, was not reinforced with stone revetments. The waterlevel was just below the crest and the seaside slope was weak. Volunteers worked to reinforce this stretch. Nevertheless, the Groenendijk collapsed under the pressure around 5:30 am on 1 February. Seawater flooded into the deep polder. In desperation, the mayor of Nieuwerkerk commandeered the river ship de Twee Gebroeders (The Two Brothers) and ordered the owner to plug the hole in the dyke by navigating the ship into it. Fearing that the ship might break through and dive into the polder, captain Arie Evegroen took a row boat with him. The mayor's plan turned out to be successful, as the ship lodged itself firmly into the dyke, saving many lives.
Several neighbouring countries sent soldiers to assist in the search and rescue. The U.S. Army sent helicopters from Germany to rescue people from the rooftops. Queen Juliana and Princess Beatrix visited the flooded area only a few days after. A large aid program came on apace, supported by the radio. A national donation program was started and there was a large amount of international aid. Politically, the disaster prompted discussions concerning the protection and strengthening of the dykes, eventually leading to the Delta Works, an elaborate project involving the closing off of most estuary-mouths.
The North Sea flood of 1953 was one of the most devastating natural disasters ever recorded in the UK. Over 1,600 km of coastline was damaged, and sea walls were breached, inundating 1,000 km². Flooding forced 30,000 people to be evacuated from their homes, and 24,000 properties were seriously damaged.
In individual incidents, 38 died at Felixstowe in Suffolk when wooden prefabricated homes in the West End area of the town were flooded. In Essex, Canvey Island was inundated with the loss of 58 lives and another 37 died when the seafront village of Jaywick near Clacton was flooded.
The total death toll on land in the UK is estimated at 307. The total death toll at sea for the UK, including the MV Princess Victoria, is estimated at 224.
In the Netherlands, an ambitious flood defence system was conceived and deployed, called the Delta Works (Dutch: Deltawerken), designed to protect the estuaries of the rivers Rhine, Meuse and Scheldt. The works were completed in 1998, upon completion of the storm surge barrier Maeslantkering, in the Nieuwe waterweg, near Rotterdam.
In the UK, the Permanent Secretary to the Home Office Sir Frank Newsam coordinated the immediate efforts to defend homes, save lives and recover after the floods; his achievements were much praised. After the flooding, major investments were made in new sea defences, and the Thames Barrier programme was started to secure central London against a future storm surge.