The Netherlands’ vast project to defend the country against the sea is finally complete. As a new sea barrier comes into operation in the town of Harlingen in the Northern Dutch province of Friesland, the Delta Works are officially finished. This brings to an end more than half a century of work, which began in response to the great flood of 1953.

“Today a sliding door in the barrier will be closed for the first time, officially bringing it into use,” says Berend Henk Huizing of the district water management authority, Wetterskip Fryslân.

It’s a massive endeavour which has cost forty million euros and was launched as long ago as 1965. “It’s taken so long because of the political discussion about the height of the sea barrier,” says Mr Huizing. “Originally the plan was to reclaim the entire Wadden Sea as polder, but this was later abandoned. It was then decided that the barrier should be made 80 centimetres higher. This was no unnecessary luxury: I’m now standing by the barrier and it’s right next to houses and shops, which of course have to be protected.”

Flood
During the night of 31 January 1953, Western Europe was hit by a massive northwesterly storm in combination with a spring tide. In the Netherlands, many dikes gave way leaving parts of Zeeland, North Brabant and the islands of South Holland under water. In total, over 150,000 hectares of land was flooded.

More than 1800 people and many thousands of animals were drowned. One hundred thousand people lost everything they owned.

Delta plan
After the flood, the Netherlands realised it had to act. The government established the Delta Commission, which recommended that dikes and dunes should be raised and strengthened, and tidal inlets closed off with dams and barriers.

The first major achievement was the completion in 1958 of the storm surge barrier in the Hollandse Ijssel, a branch of the Rhine delta. This protects the densely populated west of the country against flooding. Another highpoint was the construction of the Eastern Scheldt storm surge barrier, completed in 1986. At a length of 8 kilometres it is the longest section of the Delta Works, and one of the largest manmade structures on earth.

The Maeslantkering storm surge barrier, with its two huge moving doors, was the last major project to be completed, in 1997.

Consequences
It’s hard to exaggerate the importance of the Delta Works. The barriers and dams have reduced the stretch of coastline at risk of flooding by at least 700 kilometres. At the same time, the freshwater supply for agriculture has been greatly improved, as the boundary between fresh and saltwater has shifted to the west. The construction of dams has also increased the accessibility by road of large areas of Zeeland, which remained completely isolated until 1950.

The construction of the Delta Works has employed advanced technology, drawing widespread international attention. The American Society of Civil Engineers has declared the works to be one of the seven modern wonders of the world.

With the completion of the Harlingen barrier, the Delta Works may be officially finished, but already there is talk of a new Delta Plan. The threats created by climate change and rising sea levels call for the construction of new locks, dunes and dikes. And thus the Dutch battle against the water continues.