What we can learn from the Christmas flood of 1717

Three hundred years ago, an enormous storm surge inundated the coastal zone from The Netherlands to Scandinavia and took the lives of 17,000 people. The Christmas Flood of 1717 wasn’t the first flood to hit The Netherlands, and it wasn’t the last. Our history is full of devastating floods, and of warnings that went unnoticed. What makes the flood of 1717 particularly relevant for today is the extent of the disaster and the heroic actions by Thomas van Seeratt in Groningen.

Joost Icke, projectmanager bij Deltares (onafhankelijk toegepast kennisinstituut op gebied van water en ondergrond) raakte geïnspireerd door de Kerstvloed 1717 en onze website en schreef een blog op LinkedIN, waarin hij de lessen uit het verleden verbindt met hedendaagse vraagstukken, zoals zeespiegelstijging. 

Joost Icke, Head of Department Product Development and Services at Deltares (an independent institute for applied research in the field of water and subsurface) was inspired by the Christmas Flood of 1717 and our website. He wrote a blog article on LinkedIN, in which he combines lessons learned in the past with modern day problems, such as sea level rise.

Trained by the sea

The Christmas Flood shouldn’t have come as a surprise. Thomas van Seeratt had warned for the poor condition of the dikes, shortly after his start as head of the regional water authority. The peasants had been digging the soil near the toe of the dikes and this had destabilised them. After the flood, he managed the rescue operations with great skill and in the following years, he directed the repairs of the dikes. The dikes of Groningen survived every storm since 1717.

Map of the inundated area along the North Sea coast. Johann Baptist Homann (1718) Map of the inundated area along the North Sea coast. Johann Baptist Homann (1718)

Thomas van Seeratt was a European and a globetrotter. He was born in Sweden, had family roots in Silesia, Estonia and Sweden, and was captain of a ship in the fleet for the West Indies. Already in his first year as head of the regional water authority, he criticised the state of the dikes. The deputies tried to ridicule van Seeratt, stating that he knew nothing of dikes, because he had been at sea for twenty years. He answered them:

“Thanks to Gods goodness, I am gifted with a fair intelligence and in mathematics I have some experience. Furthermore, having travelled the seas as officer and captain of a ship, I have observed nature and man-made structures, and that the currents must not be forced, but guided softly. Such a man is the most capable of building against the sea and diverting the currents.”


Intelligence, knowledge of mathematics and water flow, leadership: these are the skills we are still looking for today. By now, we have learned our lesson. The water safety standards in The Netherlands are the strictest in the world. The water authorities take their task very seriously and inspect the dikes on a regular basis. Researchers are always on the outlook for future threats.

At Deltares, we are testing real dike sections under real wave conditions in the Delta Flume. This year, 300 years after the Christmas Flood, we are testing the asphalt from Frisian dikes. This kind of tests reveals whether the revetments are still strong enough. Renovating revetments is a costly affair and the Delta Flume has been worth its investment already.

From time to time, we even let a dike collapse on purpose. With modern sensor technology, we can measure step by step how the dike becomes instable. Experimental research is crucial for the development of the smart dike of the future, but it is also necessary to increase our knowledge of dike stability. This year, a consortium is testing the stability of the Eem dike under extreme conditions in a field experiment.


With a long history of floods, it is not surprising that researchers are investigating what the future might bring, even if the future is still uncertain. We know how to deal with uncertainty. One of the biggest uncertainties is sea level rise: will the icecaps of Greenland and Antarctica melt, or has the world moved on to renewable energy, before any of this can happen?

Just take a look at the map of the areas affected by the flood of 1717. Low lying areas, all the way from The Netherlands to Scandinavia, were inundated. Compare them to the map National Geographic made of Europe in the case of extreme sea level rise: these are the same areas that will disappear in the waves.

Three metre sea level rise in one century and another five metres in the next century would be quite a challenge for future generations. What are our options, as a nation? Concerned researchers from Deltares organised a hackaton, with renowned experts, to answer this question. A hackaton is a quick method to analyse a problem and to point at solutions, which can be studied in more detailed later on.

The researchers sketched three possible directions. The first option is to protect the entire delta as if it were a fortress and to pump the river water out of the delta into the sea. The second option is to protect the polders with huge dikes and very deep rivers in between. The third option is to elevate the delta, in its entirety, or by means of interconnected artificial hills. The options are illustrated in the picture:

Three options for keeping The Netherlands habitable at extreme sea level rise (©Beeldleveranciers-Carof). Three options for keeping The Netherlands habitable at extreme sea level rise (©Beeldleveranciers-Carof).


Given our history, it is reassuring that we are preparing ourselves to live with more water. We are already implementing solutions that match with nature and our lifestyle, such as the Sand Engine near the coast of The Hague and the Water Squares in the city of Rotterdam. The practical approach of the Dutch doesn’t go unnoticed.

In many countries, investments in dikes are profitable to avoid the damage done by floods. Worldwide, countries are interested in the Sand Engine, a method to strengthen the coast by means of large scale sand nourishments and natural currents. An article in the New York Times portrays The Netherlands as a nation that sees climate change as an opportunity. The leadership of a small country can have a large impact on the world, although we regard ourselves as a no-nonsense people.

Modesty is a good trait, but we can also be too modest. It may seem that we, as a small nation, have limited influence on the root cause of climate change: emission reduction. Compared to the largest nations of the world, any effort feels like a drop in the ocean. However, we also know that it only takes a world cup final to be in the centre of the world. The Netherlands can put more emphasis on the solutions we have on offer to reduce CO2-emissions.

We are in the race to produce the cheapest wind energy in the world, because our offshore sector has the expertise to build at sea. We have smart software to balance supply and demand of sustainable energy sources via the electricity network. We foster a start-up culture, with real gems in clean tech. Our automated greenhouse can be self-sustaining with energy and water.

These examples show technological leadership and professional pride. CO2-neutral solutions could get a more prominent position in our portfolio, as part of a broader climate strategy.


The Flood of 1717 is commemorated in Groningen with art, exhibitions and historic material. We know so much about the time, because Thomas van Seeratt kept a journal during his days in Groningen. He noted some remarkable stories of the rescue operations in the winter of 1717-1718. He also wrote about the negotiations that were needed to get things done.

One of the toughest discussions concerned who should pay for the strengthening of the dikes: the landowners near the dike, or everyone in the province? The decision that everyone in the hinterland had to contribute to the flood defences culminated in a farmer revolt in 1718.

Nowadays, we regard it as normal that the government taxes us for water management and implements climate adaptation measures. However, the climate crisis cannot be outsourced to the government alone and good luck with that. The solutions are in everyone’s hands: politicians, businesses and civilians alike.


Let’s draw three lessons from The Christmas flood of 1717. First of all, Thomas van Seeratt is an example for today’s scientists and engineers, because he spoke up with authority when he needed to. Secondly, the low lying area in Northwest Europe that was inundated in 1717 is the same area that is under threat from extreme sea level rise. Let’s discuss our options and not hide from our responsibility to keep our country safe for future generations. Thirdly, people must work together as a team to solve the climate crisis. It is not the sole responsibility of those living near the dike. It is the responsibility of everyone who is protected by the dike.

by Joost Icke - Head of Department Product Development and Services at Deltares
This article has also been published on Icke's LinkedIn blog.

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