Transcription
Foreign.
[Music] Did you know that most of the Netherlands is actually below sea level? The Dutch have spent centuries building large-scale sea defenses to push back water and protect themselves against disasters. They've managed to reclaim almost 20 percent of their land from the sea and lakes. Here's how they did it.
The Netherlands is often associated with polders. Polders are low-lying areas of land that were reclaimed through the building of dikes, drainage canals, and pumping stations. To create a polder, the Dutch first needed to build a dike around a section of water. Then, they used windmills to pump water out of the lowlands and back into the rivers, so the land could be farmed. Today, there are more than 3,000 polders nationwide. That accounts for about half the country's land area.
The polders, dikes, and windmills were mostly a success, but after severe flooding in 1916, the Dutch began work on the Afsluitdijk, a ditch to protect low-lying areas and wall off the Zuiderzee from the sea. The sea wall was one of the largest engineering feats of its time, spanning 20 miles in four locations. On the mouth of the Zuiderzee, material was deposited onto the sea floor until it broke through the surface. Rocks strengthened the dike, and a combination of sand and clay was used to raise it to its final height of 23 feet above sea level. It was then topped off by sand and clay and held together by grass to make this causeway and one of Europe's largest lakes. Shipping locks and discharge sluices were built at both ends of the dike. As the Zuiderzee was fed by freshwater rivers and streams, saltwater was discharged into the sea, and eventually, the Zuiderzee became the IJsselmeer, a shallow freshwater lake.
At the same time, the new province of Flevoland was reclaimed from the water via the Afsluitdijk, credited with saving parts of the country during a devastating flood in 1953 that killed more than 1,800 people. But radical change was still needed. This led to the Delta Works, a series of dams, sluices, locks, dikes, levees, and storm surge barriers. The works have been declared one of the seven wonders of the modern world by the American Society of Civil Engineers. They also cost the country five billion dollars.
After a series of floods in 1993 and 1995, the country was forced to think beyond barriers and canals for water management. Instead, they invested $2.7 billion in the Room for the River Project. The goal was to control flooding by working with the water, as opposed to against it. In the Waal, near Nijmegen, for example, a closed-off tributary was reopened to mimic natural floodplains, absorbing water from the nearby river and ensuring it didn't overflow. Reservoirs like this are called catchment areas and often double as wildlife preserves.
Without all of these innovative techniques, it's estimated that about 65 percent of the Netherlands would currently be underwater at high tide. As sea levels continue to rise and hit all-time highs, there's been an increase in the number of severe storms, leaving sea walls like the Afsluitdijk in need of strengthening. To reduce the use of materials and costs, engineers came up with a simple solution. They'll strengthen the sea wall by adding a layer of reinforced blocks along the barrier, which takes 35 percent less concrete to produce than normal concrete blocks. They'll build new pumps that operate with very low energy consumption and are fish-friendly. Solar panels will compensate for the energy used, resulting in an energy-neutral dike.
Of course, the Netherlands isn't the only country combating rising sea levels. There's a lot we can learn from the techniques they've developed over the centuries. After all, the Dutch have a saying that goes, "God created the world, but the Dutch created the Netherlands."
Thank you.
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