The Gates Against the Sea

On the night of Saturday, 31 January 1953, a great storm blew down from the north-west across the North Sea.

It came at the worst possible time, together with a spring tide, when the sea rises highest. The wind pushed the water towards the low coast of the Netherlands and piled it up against the dykes, the long earth walls that kept the sea off the land.

In the south-west of the country, in the province of Zeeland and the islands around it, most people were asleep. Many of the dykes there were old and too low. In the early hours of Sunday morning, the water began to pour over them. Then the dykes started to break.

The night of the flood

Families woke to water coming under their doors. Some climbed into their attics or onto their roofs. Others had no time. In those days the radio did not broadcast through the night, and in many villages there was no way to warn anyone.

By morning, whole islands and farmlands had become a grey sea, with only roofs, church towers and treetops showing. The storm went on into the next day, and more dykes failed.

In the Netherlands, 1,836 people died. Tens of thousands of animals drowned. Many tens of thousands of people had to leave their homes. The same storm also took hundreds of lives in England and in Belgium.

Help came from all over the country and from abroad. Soldiers, fishermen and volunteers went out in small boats to rescue people from roofs. Amateur radio operators kept messages moving when the telephone lines were down. Other countries sent helicopters, boats, food and money.

Closing the gaps

There were dozens of breaches in the dykes, and every day the tides flowed in and out through them, tearing them wider. Closing them was a race.

The last and most difficult gap was at Ouwerkerk, on the island of Schouwen-Duiveland. It was finally closed on 6 November 1953, using huge concrete boxes called caissons. They had been built during the Second World War to make a temporary harbour for the D-Day landings in France. Floated into place and sunk, they sealed the dyke.

Those same caissons still stand at Ouwerkerk. Today they hold the national museum of the 1953 flood.

A plan for ten thousand years

Only three weeks after the flood, the government set up a group of experts called the Delta Committee. Its task was to make sure that such a disaster could never happen again.

The engineer Johan van Veen, who worked closely with the committee, had warned for years that the dykes in the south-west were too weak. He and others had already sketched a bold idea. Instead of raising hundreds of kilometres of dyke along every winding sea inlet, why not close off the mouths of the inlets themselves? This would make the coastline far shorter, and far easier to defend.

The committee agreed. It also set a new standard. The sea defences protecting the heart of the country, where most people lived, should be strong enough to hold back a storm so severe that it might be expected only once in ten thousand years.

In 1958, parliament passed the Delta Act. The work had already begun, and it would continue for almost four decades.

Dams, sluices and a change of mind

One by one, the great dams went up across the estuaries of Zeeland and South Holland. Some were built of sand, stone and concrete blocks dropped from cable cars strung high above the water. Others had sluices that could let river water out to sea.

The dams did something else as well. Roads were laid along their tops, and islands that had been reached only by ferry were joined to the rest of the country. Farmers could get their crops to market. Children could reach new schools. Zeeland, once remote, opened up.

Then came the biggest estuary of all, the Eastern Scheldt. The plan was to close it completely. But closing it would turn salt water into still water and destroy the mussel and oyster beds, the fishing, and the rich life of the tidal mudflats. Fishermen, scientists and nature lovers protested.

The government listened. In 1976, it changed the plan. Instead of a solid dam, engineers would build a storm surge barrier: a row of 62 enormous steel gates set between concrete pillars. Normally the gates would stay open, letting the tides flow in and out. When a dangerous storm came, they would close.

Queen Beatrix opened the Eastern Scheldt barrier on 4 October 1986. It is still the largest of the Delta Works.

The last gates

The final piece was built near Rotterdam, to guard the busy waterway to one of the world's largest ports. Ships had to be able to pass at all times, so the engineers designed two vast curved arms that lie in dry docks on either bank. When a storm threatens, they float out and sink to close the channel. Each arm is about as long as the Eiffel Tower is tall.

It was finished in 1997. The Delta Works were complete.

Today, millions of people live and work below sea level in the Netherlands, more safely than before. The work goes on, because the sea is rising, and the Dutch now also give their rivers more room to spread out safely. But on the night of every storm, the gates are there.

Want to read more?

The Watersnoodmuseum at Ouwerkerk tells the story of the flood through the memories of survivors, inside the very caissons that closed the last gap. Rijkswaterstaat, the Dutch water authority, publishes clear accounts of each part of the Delta Works. Johan van Veen's Dredge, Drain, Reclaim, written before the flood, explains the long Dutch struggle with the sea.