Dutch storm surge barriers: forever prepared
They are needed whenever they are called for: the six storm surge barriers built to protect the Netherlands from extreme high tides. Together they form the Netherlands’ largest system of coastal flood defences and have helped put the country’s water management infrastructure firmly on the international map. But they also have a tragic backstory.
150.000 ha of land lost to the sea
Much of the Netherlands occupies a delta region which lies under sea level. This means that 18 million people are under threat of flooding. It’s a fact that’s often taken for granted, but nevertheless, it’s one that defies nature.
History has proven this true: in the evening of Saturday 31 January 1953, a wind-force 10 storm battered the Dutch coastline. A raging north-westerly storm, coupled with a spring tide, caused severe flooding. Floodwaters surged to unprecedented levels.
Dykes were breached in Zeeland, Zuid-Holland and Noord-Brabant in more than 150 places, unable to hold back the huge volumes of water. The effects were catastrophic. The Great Flood of 1953, or Watersnoodramp, cost the lives of 1.836 people. Damage to infrastructure and agricultural land was enormous: around 150.000 ha of land were inundated.
The Hollandsche IJssel Barrier: first line of defence
Soon afterwards, the Dutch government decided to put in place a system of defence works to withstand any future floodwaters. The first of these was the Hollandsche IJssel Barrier. This surge barrier protects the coastal hinterland using two gates, each over 80 m wide and 12 m in height, which can be lowered into the water when required.
Without this barrier, the region between Rotterdam and The Hague, an area which is home to hundreds of thousands of people, would be at risk of inundation. The Hollandsche IJssel Barrier is the first of six storm surge barriers built to protect the Netherlands.
Moving gates to combat flooding
After the IJssel Barrier, four more barriers were constructed: the Haringvliet Locks; the Eastern Scheldt Barrier; the Hartel Barrier; and the Storm Surge Barrier Ramspol. However, one major waterway proved more difficult to protect: the Nieuw Waterweg. This waterway affords access to the port of Rotterdam from the North Sea and cannot easily be closed off.
For that reason, the Maeslant Barrier was built: a ‘moving’ barrier which, when open, does not impede shipping. This barrier can hold back initial surges of seawater of up to 5 m above NAP (the NAP level of zero is about equal to the average sea level in the North Sea). No other surge barrier in the world has moving parts which are larger than here.
Testing the giants
Every year, these storm surge barriers undergo functional testing. The Maeslant Barrier and Hartel Barrier are closed in order to verify that summer maintenance has been carried out correctly. Additionally, the on-site teams who operate the barriers are also tested.
This functional testing is performed so that we are properly prepared for storm surges and ensures that scenarios of inundation and breached dykes like in 1953 never become reality again.
Knowledge = sharing
As a result of this ‘cohabitation’ with water, the Netherlands has, over a period of seventy years, built up a wealth of knowledge in the field of water management we are happy to share this with international partners.
For example, after the devastation caused by Hurricane Katrina, the authorities in the US called upon this specialist Dutch expertise. Rijkswaterstaat (in collaboration with Deltares and engineering consultants) gave advice on storm surge barriers.
Amongst other things, this led to the construction of the IHNC Lake Borgne Surge Barrier, one of the largest of its kind in the US.
Learning lessons worldwide: I-STORM and more
In addition to sharing this knowledge, we are also keen to add to own know-how. For example, on a visit to the US by Rijkswaterstaat in April 2025: this visit was not only meant to emphasise the importance of the links with the Netherlands, but also to learn lessons from each other and to exchange expertise.
This process of reciprocal learning also includes collaboration via I-STORM: a worldwide network of authorities in charge of storm surge barriers. Via this network, it’s possible to learn about best practices from across the world.
For example, the MOSE storm surge barrier, an innovative system of 78 mobile gates which helps defend Venice from the effects of floodwaters from the Adriatic Sea. This collaboration gives us an insight into alternative technologies, which can be of interest when building new barriers in the Netherlands.
This way, we can continue improving our know-how and protect the Netherlands and the rest of the world against flooding.