[Note that this article is a transcript of the video embedded above.]

This is the Veluwemeer (velOOwemeer) Aqueduct in Harderwijk (HAR-der-vehk), Netherlands. It solves a pretty simple problem. If you put a bridge for vehicles over a navigable waterway, you often have to make it either very high up with long approaches so the boats can pass underneath or make it moveable, which is both complicated and interrupts the flow of traffic, wet and dry. But if you put the cars below the water, both streams of traffic can flow uninterrupted with a fairly modest bridge. Elevated aqueducts aren’t that unusual, but this one is just so striking to see, I think, because it looks just like a regular highway bridge, except…the opposite.

When I was a little kid, I read this book, The Hole in the Dike, about a Dutch boy who plugged a leak with his finger to save his town from a flood. And ever since then, as this little kid grew up into a civil engineer with a career working on dams and hydraulic structures, I’ve been kind of constantly exposed to this idea that the Netherlands is this magical country full of fascinating feats of civil engineering, like Willy Wonka’s chocolate factory but for infrastructure. I’m not necessarily proud to say this, but I think it’s true for a lot of people (especially here in the US) that my primary cultural touchpoint with the Netherlands is just that they’re really good at dealing with water. You know, you don’t have to browse the internet for very long to find viral (and sometimes dubious) posts about Dutch infrastructure projects. Sometimes, it feels like half of my comment section on YouTube is just people telling me that the Dutch do it better.

I’m naturally skeptical of things that seem larger-than-life, especially when it comes to engineering. And without context, I think it’s hard to separate myth from facts (this TikTok video being a myth, by the way.) Here’s the actual scale of a cruise ship compared to the aqueduct. So let’s take a look at a few of these projects and find out if the Dutch really have the rest of the world outclassed when it comes to waterworks. And I’ll do my best to pronounce the Dutch words right too. Ik ben Grady, en dit is Practical Engineering.

The first hint that the Dutch really do lead the world in water infrastructure is in the name of the country itself: The Netherlands translates literally to the lowlands, and that’s a pretty good description. A large portion of the country sits on the delta of three major rivers - the Rhine, the Meuse/Maas (MAHss), and the Scheldt (SHELLt) - that drain a big part of central Europe into the North Sea. Those rivers branch and meander through the delta, forming a maze of waterways, islands, inlets, and estuaries along the coast. About a quarter of the country sits below sea level, which creates a big challenge because it’s right next to the sea!

As early as the Iron Age, settlers were involved in managing water. Large areas of marshland were drained with canals and ditches to convert them into land that could be used for agriculture. These plots of land, which, through human intervention, were hydrologically separated from the landscape, became known as polders. And the tradition of their engineering would continue for centuries to the present day. Unfortunately, that marshland, being full of organic material, decomposed over time. That, combined with the drainage of groundwater, caused the polders to sink and subside, increasing their vulnerability to floods.

And that is kind of the heart of it. The Netherlands is a really valuable and strategic area for a lot of reasons: it’s flat; it has great access to the sea and major rivers providing for fishing and trade; it has prime conditions for farming and pastures, making it the second largest exporter of agricultural products in the world. The problem is that all those factors come with the downside of making the country extremely susceptible to floods, both from the North Sea and the major rivers that flow into it. So for basically all of its history, people were building dikes, embankments of compacted soil meant to keep water out of low-lying areas. Over the centuries, huge portions of the sinuous Dutch coastline became lined with dikes, and the individual polders were often ringed with dikes as well to keep the interior areas dry.

Of course, you still get rain inside a polder, plus irrigation runoff and sometimes groundwater, so they have to be continuously pumped out. And before the widespread use of electric motors and combustion engines, the Dutch used the source of power they’re famous for: the wind. Windmills - or more accurately windpumps, since they weren’t milling anything in this context - could be used to turn paddle wheels or Archimedes screws to move water up and over dikes, keeping canals and ditches within the polders from overflowing. Over time, poldering dry-ish land, the Dutch realized they could use exactly the same technique to reclaim land from lakes. Typically land reclamation is done by using fill - soil and rock brought in from elsewhere to raise the area above the water. But it’s not the only way to do it, and it’s not that useful if you want to use that area for agriculture since the good soil is under the fill. Another option is to enclose an area below the water level, and then just get rid of the water. In this way, you can create arable land just for the cost of a dike and a pump. If you love cheese, you might be interested to learn that one of the first polders in the Netherlands reclaimed from a lake was Beemster. The soil of the ancient marsh provides a unique flavor of the famous Beemster cheese.

One glaring issue with reclaiming land by drawing down the water instead of building up is that the low-lying polders are still vulnerable to floods. In 1916, a huge storm in the North Sea coincided with high flows in several rivers, flooding the Zuiderzee (ZIder-ZAY), a large, shallow bay between North Holland and Friesland (FREEZE-lahnd). The flood broke through several of the dikes, leading to catastrophic damage and casualties. Although the idea had been in discussion for years, the event provided the impetus for what would become one of the grandest hydraulic engineering projects in the world.

One of the major issues with the Zuiderzee (ZIder-ZAY) flooding from a surge in the level of the North Sea is the sheer length of the coastline that has to be protected. Building adequately large and strong enough dikes to protect it all would be prohibitively expensive and just plain unrealistic. So Dutch engineers devised a deceptively simple solution: just shorten the coastline. If the effective coast of the Zuiderzee (ZIder-ZAY) could be substantially shorter, resources could go a lot further toward protecting the area against floods. So that’s just what they did.

Between the late 1920s and early 1930s, a 20-mile (or 32-kilometer) dam and causeway called the Afsluitdijk (AWF-schlite-dike) was built across the Zuiderzee (ZIder-ZAY), cutting it off from the North Sea. Construction spread outward from four points, the coast on either side, and two small artificial islands built specifically for the project. The original dam was built from stones, sand, glacial till, stabilizing “mattresses” of brushwood, and thousands upon thousands of hand-laid cobblestones.

Cutting off the Zuiderzee (ZIder-ZAY) from the ocean turned it into a large, and ultimately freshwater lake called the Ijsselmeer (ICE-el-meer), named for the river that empties into it. But that inflow is an engineering challenge. Without a way for it to reach the sea, the lake would just overflow. So, these sluices are like gigantic outflow valves that allow excess freshwater constantly building up in the Ijsselmeer (ICE-el-meer) to be discharged into the sea, as it would have been back when it was still the Zuiderzee (ZIder-ZAY). The sluices, which are titanic hydraulic engineering structures themselves, typically use gravity to drain water during low tide. When that passive discharge isn’t enough, new high-volume pumps can be used to make sure the level of the Ijsselmeer (ICE-el-meer) stays within the ideal range.

Over the last few years, the Afsluitdijk (AWF-schlite-dike) has been undergoing a major facelift. With sea levels rising and the frequency of extreme weather events rising with it, the Dutch have completed a major overhaul, raising the crest of the dam by about 2 meters, adding thousands of huge concrete blocks to break waves and strengthen the structure. The larger blocks that are always in contact with the sea are truly gigantic, over 70,000 of them weighing six and a half metric tons EACH!

The project also included upgrades to the lock complexes and sluices. And the highway that runs along the top is also getting upgrades (including, in true Dutch fashion, the bike lanes too). And human passage isn’t the only consideration for the project either. The Fish Migration River will allow fish to swim between the North Sea and the Ijsselmeer (ICE-el-meer) and river ecosystems upstream. The stark contrast between freshwater and saltwater is hazardous to fish, so the migration river spreads out the salinity gradient into something more manageable. It’s like a fish ladder, but on top of having an elevation gradient, it also is a ramp of saltiness.

With the shallow Zuiderzee (ZIder-ZAY) protected from the North Sea, the Netherlands saw an opportunity to increase its food supply by creating new land. Over the middle decades of the 20th century, the Dutch built four gigantic polders in areas that were once the seafloor. These polders were built using the same principles as before, just with scaled-up 20th-century technology. There are even examples of our old friends, Archimedes screws being used, albeit with modern electric motors. Wieringermeer (veeRING-er-meer) and Noordoostpolder (NORD-OHST-polder) were built first, but the Dutch faced a problem. With such large areas of land dried up, the groundwater in adjacent areas flowed out and into the polders, causing subsidence and loss of freshwater needed for agriculture. The following polders, a pair of adjacent tracts called Eastern and Southern Flevoland (FLAYvo-lahnd), avoided this by retaining a small series of connected lakes. These bordering lakes keep the polders hydrologically isolated from the mainland, and this is also where you’ll find the Veluwemeer (velOOwemeer) aqueduct. The later three polders became Flevoland (FLAYvo-lahnd), a totally new province of dry land reclaimed from the sea. A succession of carefully selected crops were grown to rehabilitate the salty soil, making it fertile enough to farm. All you need to do to see how well it worked is look at these aerial photos of all the farmland in Flevoland (FLAYvo-lahnd)!

There were plans for a fifth polder called the Markerwaard (MAHRKer-vahrd), and a huge dike was actually constructed for it. Hangups going as far back as the German Occupation of the Netherlands in the Second World War, to later environmental concerns, stopped the polder from being completed. The dike did create another freshwater reservoir, the Markermeer, and only recently, an artificial archipelago called the Marker Wadden (MAHRKer-vahdden) was built as a nature conservation project and host to migratory birds, fish, and ecotourists alike.

Even as the Zuiderzee (ZIder-ZAY) Works protected parts of the Netherlands, many parts of the country were still facing threats from flooding. In the winter of 1953, an enormous storm in the North Sea raised a major storm surge, crashing into the delta, causing floodwaters to overwhelm much of the already existing and extensive flood control structures of the Netherlands. A staggering 9% of all of the farmland in the whole country was flooded, 187,000 farm animals drowned, nearly 50,000 buildings were damaged or destroyed, and over 1,800 people perished. It was one of the worst disasters in the history of the country.

Just as with the Zuiderzee (ZIder-ZAY), the extraordinary length of the coastline of this area meant that adequately strengthening all the dikes in response to the storm wasn’t feasible. So, an incredibly intricate plan called the Deltawerken or Delta Works was put into motion to effectively shorten the coastline with a series of 14 major engineering projects, including dams, dikes, locks, sluices, and more. Unlike with the Zuiderzee (ZIder-ZAY) Works, fully enclosing the area and cutting off the sea wasn’t an option. Firstly, the Rhine and Meuse/Maas (MAHss) have gigantic flows. The Rhine is one of the largest rivers in Europe, and that can’t just be walled off. There are also concerns about environmental impacts and ensuring the easy movement of the huge amount of shipping that uses this waterway. So, many of these structures have to be functionally non-existent until they’re needed. The resulting projects, along with the Zuiderzee (ZIder-ZAY) works, have shortened the Dutch coast by more than half since the 19th century. These feats are so impressive they are on the American Society of Civil Engineering’s list of wonders of the modern world. And it’s easy to see why when you take a look.

This is the Oosterscheldekering (OH-ster-SHELL-de-keering), the largest of all the Delta Works. It was initially designed to be a closed dam, similar in some ways to the Afsluitdijk (AWF-schlite-dike). If constructed as initially conceived, it would create another large freshwater lake. But, by the time it was under construction in the 1970s, environmental impacts were much more appreciated than they were in the 20s and 30s. So the dam was designed to include huge sluice gates to allow massive tidal flows during normal conditions while retaining the ability to fully close off the inland portion of the Delta from the sea during storm conditions.

The Oosterscheldekering (OH-ster-SHELL-de-keering) comprises two artificial islands and three storm surge barrier dams connecting them. The larger of the islands also contains a lock, allowing for ships to pass through. The floodgates are staggering in scale; there are 62 steel doors, each 138 feet (or 42 meters) wide and weighing up to 480 metric tons! Even the piers between them were a monumental effort. They were built offsite, maneuvered into place with custom-built ships, then filled with sand and rock to sink them into place. Special ships also had to compact the seabed with vibration before placing the pillars.

Another notable structure in the Delta Works is the Stormvloedkering Hollandse IJssel (storm-FLODE-keering--hoLAHNDse-ICE-el), a storm surge barrier protecting Europe’s largest seaport. The project has it all: a lock to allow for the passage of ships, a bridge for road traffic with a fixed truss and a moveable bascule portion crossing the lock, and two gigantic, moveable storm surge barriers crossing the main sluice. Each of these barriers is strengthened by a truss arch which makes them look like sideways bridges when viewed from above.

And then, there’s the Maeslantkering. This is probably the most impressive storm surge barrier on the planet. Those tiktoks showing out-of-scale cruise ships crossing Veluwemeer (velOOwemeer) should have just shown actual gigantic ships cruising through the huge ship canal safeguarded by the Maeslantkering. It’s hard to communicate the scale of the two gates; they’re considered one of the largest moving structures on earth. And moving them is a process. The gates normally sit in dry docks. When it’s time to close them, the dry docks are flooded, and the hollow gates float in place. Then they’re pivoted around gigantic ball-and-socket joints at the ends of the truss arm. Each door is 690 feet (or 210 meters) wide, and once in place, they are flooded with water, so they sink to the bottom, completely blocking even the fiercest storm surge. In the event that the doors remain closed long enough for the flow of the Rhine to build up dangerously high on the inland side, they can be partially floated, allowing for excess river water to run out to sea.

Since its completion in 1997, aside from annual testing, the Maeslantkering (mahs-LAHNT-keering) has only been closed twice: once in 2007 and again in 2023. And to me, that tells the story of Dutch waterworks more than anything else. It’s all a huge exercise in cost-benefit analysis. Look at two alternate realities: one where the Delta Works weren’t built and one where they were. And then just compare the costs. In one case, the costs are human lives, property damage, agriculture losses from saltwater, and all the disaster relief efforts associated with, so far at least, just two big storms. And in the other case, the costs are associated with designing, building, and maintaining an infrastructure program that rivals anything else on the globe. The question is simple: which one costs more? Look at many other places in the world, and the answer would probably be the Delta Works. Just the capital cost was around $13 billion dollars, and that doesn’t include the operation and maintenance, or environmental impacts of such massive projects. But in the Netherlands, where a quarter of the country sits below sea level, it’s a fraction of the cost of inaction.

In the United States, most flood control projects are designed to protect up to the 1-in-100 probability storm. In other words, in a given year, there’s a 99% chance that a storm of that magnitude doesn’t happen. In the Netherlands, those levels of protection are much higher. River structures go from the 1-in-250 all the way to 1-in-1,250 and flood protection from the North Sea goes up to 1 in 10,000-year event. It only makes sense because practically the entire country is a floodplain; massive investment in protection from flooding is the only way to exist. And those projects come with other costs too. The Zuiderzee (ZIder-ZAY) Works cost the entire area’s fishing industry their livelihoods, and some consider converting such a large estuary into a freshwater lake one of the country’s greatest ecological disasters.

So there are no easy answers, and the Netherland's battle against the sea will never really be over. Major waterworks are just the reality of the country, and they keep evolving their methods. One example is the Room for Rivers program which is restoring the natural floodplain along rivers in the delta. Another is the sand engine, an innovative beach nourishment project that relies on natural shoreline processes to distribute sand along the coast. The Dutch government expects the North Sea to rise 1 to 2 meters (or 3 to 7 feet) by the end of this century, meaning they’ll have to spend upwards of 150 billion dollars just to maintain the current level of protection.

That sounds like a staggering cost, and it is, but consider this: that investment in protection for a major part of the country over three-quarters of a century is approximately equal to the economic impact of Hurricane Katrina, a single storm event in the US. Of course, the damage during Katrina was amplified by engineering errors, and we’re far from comparing apples-to-apples, but I think it’s helpful to look at the scale of things. Decisions of this magnitude are difficult to make, and even harder to execute, because we can’t visit those alternate realities to see how they play out. But what we can do is look at the past to see how decisions have played out historically, and there’s no place on Earth with a longer history of major public water projects than the Netherlands. In fact, the US Army Corps of Engineers and the Dutch government agency in charge of water, the Rijkswaterstaat (rikes-VAHter-stat), have had a memorandum of agreement since 2004 to share technical information and resources about water control projects. And in the aftermath of Hurricane Katrina, the Army Corps consulted with the Rijkswaterstaat (rikes-VAHter-stat) to help decide how to rebuild New Orleans’s flood defense system.

In 2021, those systems were put to the test when the region was pummeled by Hurricane Ida. It was an extremely powerful storm, and the torrential rains and violent winds did enormous damage. But the storm surge was repelled by the levees, barriers, and floodgates built with the assistance of Dutch waterworks engineers. Many signs point to storms getting stronger and surges getting higher, which means that practically the whole world is in an uphill battle with floods. So we all benefit from that relatively small country with its low-lying delta lands, buttressed against the sea, and the expertise and knowledge gained by Dutch engineers through the centuries.