How does the Netherlands reclaim land from the sea? They build a dike and then pump out the water.
Before we look at how they do it, I thought it would be interesting to learn why Holland is called the Netherlands. Most of you probably know this, but I didn’t. The Netherlands is the official name for the country and Holland is just one region within it. Just like the United Kingdom is the official name for the country and England is just one area within it. The Netherlands means “low lands” in Dutch. It consists of 12 provinces, two of which are North Holland and South Holland. These used to be one province called Holland and over one third of the entire population of the Netherlands lives in them. For most of modern Dutch history, Holland was the most economically successful of all the provinces and became known to international traders and sailors. They started to call all of the Netherlands Holland, and it stuck. All of the people that live outside of North and South Holland object to the country being called Holland in the same way that people in Scotland and Wales object to the UK being called England.
The Netherlands is called the low lands because 26% of the country is below sea level. The early settlers in the area built their villages on mounds to raise them up and protect them from flooding caused by the North Sea. They soon learned that they could protect their villages better by walling up the sea, and then they realized they could take land from the North Sea. Since then, the Netherlands has bee growing year by year. In fact, the 12th province, called Flevoland, is entirely reclaimed from the sea and didn’t exist when the Kingdom of the Netherlands came into being. Since the 14th century, the Kingdom of the Netherlands has been reclaiming land to make the country larger. There is a famous saying: “While God created the Earth, the Dutch created the Netherlands.” How do they do it? Modern methods are different to the original methods, but the general practice is still the same.
The first step is to build a dike to cut off the piece of land to be reclaimed from the sea. The word dike came into English and Dutch from old German. It means a trench or an earthwork and is the root of our word “ditch”. These days, heavy machinery and ships are used to move the materials to build dikes, but they would have been built by hand in the 14th century. They use a core of sand, which gives the dike a strong structural base. Then they cover it in a thick layer of impermeable clay which stops water from leaking through and damaging the integrity of the dike. Once it is in place, they plant grass on it because the grass protects the surface and the roots hold the dike together. If they need to build on top of the dike, they also use steel reinforcement.
Once the dike is built and the sea held back, the water needs to be removed. These days, it is pumped out with machines that can move thousands of gallons of water a minute, but in the very beginning the water had to be pumped out by hand, or using pumps driven by animals. Then, in the 15th century, the Dutch realized that they could use windmill power to pump out the water and that led to a sudden increase in the amount of reclaimed land.
After the water is removed, the soil needs to be treated because the seabed is very salty and has a high clay content. To fix that, the Dutch dig ditches to flushes out the excess salt whenever it rains. They plant crops that can fix the soil and slowly rotate them as well. It takes a while, but this fixes the soil.
After the land is reclaimed, they can’t just sit back and do nothing because the sea is always trying to fight back. The dikes needs to be constantly maintained. Rising sea levels is also a problem. However, through land reclamation, the Dutch have managed to increase the size of the Netherlands by 20%.
This is not the only way to reclaim land. You can also simply pour earth, concrete, or other materials into the sea until you make an island. The airport in Osaka, Japan was made this way. However, as they have learned, the reclaimed land is always sinking and has to constantly be built up. The Netherlands may have found the best way to reclaim the land. And this is what I learned today.
Sources
https://www.thoughtco.com/polders-and-dikes-of-the-netherlands-1435535
https://en.wikipedia.org/wiki/Land_reclamation_in_the_Netherlands
https://en.wikipedia.org/wiki/Land_reclamation
https://en.wikipedia.org/wiki/Netherlands
https://www.etymonline.com/word/dike
Photo by ERIC POUSSIN: https://www.pexels.com/photo/green-windmill-in-zaanse-schans-25338519/