The Netherlands vs the sea: The race to hold back rising waters | CNN

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The Netherlands has spent decades building and perfecting one of the most sophisticated water-defense systems in the world. With one quarter of the country below sea level, water remains an ever-present threat, and defending against it — from the rising levels of the North Sea to overflowing rivers — is central to the country’s survival.

But as the rate of sea level rise continues to increase and extreme weather becomes more frequent, experts say the systems that kept the country safe for decades will struggle to keep pace without significant upgrades.

“We live in a bathtub and the bathtub will fill up,” said Co Verdaas, commissioner for the national water defense program, the Delta Program.

“And because we fully trusted centuries of technical water management, we forgot how vulnerable we are,” he told CNN. “We are literally also accessing the limits of what we can do with technical management.”

A report published in March 2026, which analyzed 385 peer-reviewed studies, found that current global coastal sea level has been underestimated, and is on average around 1 foot higher than currently assumed, with some places — such as Southeast Asia and parts of the Pacific — reaching up to 3 feet higher.

The Netherlands’ extensive system of storm-surge barriers, known as the Delta Works, has protected it for decades.

Spanning roughly 1,000 kilometers (621 miles), the Delta Works consists of more than a dozen major components, including dams, dikes, levees, sluices and pumps. Completed in 1997, it is built to hold back the sea and is widely seen as a global model for how modern infrastructure can protect coastal areas.

Construction began after the devastating North Sea Flood of 1953, which left more than 2,000 people dead along the coasts of the Netherlands, Belgium and the United Kingdom. The disaster, the worst in the Netherlands since the Middle Ages, led to the development of a comprehensive system aimed at preventing future flooding.

“If you look a bit back in our history, we had this strong tendency to think that we could control water,” said Joep Verhagen, lead expert on water and urban resilience issues at the Global Center on Adaptation, in the Netherlands. “Controlling nature gets harder and harder with climate change. So from controlling water, we moved towards living with water, accepting that we could not always control nature.”

While the Netherlands’ infrastructure remains among the best in the world, the rapid pace of climate change means parts need updating, said Harold van Waveren, water safety adviser at Rijkswaterstaat, the national water management agency.

“Because if you replace some infrastructure, the idea is that it will work for another 50 or 100 years,” he said.

“We feel so safe because it’s going well. It has been going well — until now,” van Waveren added.

Delta Works combines over 20,000 kilometers of dikes and storm-surge barriers with thousands of pumping stations.

“That’s our main basis,” van Waveren said, to ensure “this country exists.”

The pumps vary in size, with the largest currently pumping about 250 cubic meters (8,829 cubic feet) per second, he said. Yet, pumping capacity may need to increase dramatically. “One of the options could be to construct pumping stations at around 2,000, 3,000, 5,000 cubic meters per second (70,629 – 176,573 cubic feet per second), maybe at the end of this century, to stay safe.”

Some Delta Works structures, such as fixed dams, block the sea. Others — particularly movable storm-surge barriers — remain open under normal conditions to allow shipping and natural ecosystems to function but can close during extreme storms.

Opened in 1986 and stretching 9 kilometers (5.6 miles), the Oosterscheldekering, the world’s largest storm surge barrier complex, has 62 movable gates that remain open under normal conditions to allow the tide to flow naturally, and close only during exceptionally high water levels.

Since it was built, the barrier has closed roughly 30 times — about once per year on average — but under extreme climate scenarios, it might close as many as 20 times a year, putting increased mechanical stress on the gates, according to a report by the Royal Netherlands Meteorological Institute (RNMI).

Another major water defense structure, the Maeslant Barrier, in the southwest, was built to protect the city of Rotterdam and more than 1 million people from flooding. The automated storm surge gate has two movable arms, each 210 meters (689 feet) wide, 22 meters (72 feet) high and 15 meters (49 feet) deep, which can sink to the bottom of the waterway within about two hours when the barrier closes.

It was designed to close roughly once per decade. In 2023, high water levels caused by Storm Pia triggered an automatic closure and authorities warn that if water levels continue to rise sharply, the waterway to one of Europe’s largest ports may have to be closed permanently.

“Maybe for our safety in the longer term, we have to close it. It’s not an issue now,” Verdaas said, “but with two meters (6.7 feet) of sea level rise, it’ll be at the end of the century. And you can imagine the impact — the Port of Rotterdam is one of the biggest ports in the world.”

Global sea levels are projected to rise by around 0.3 meters (1 foot) to just over 1 meter (3.3 feet) by 2100, depending on future greenhouse gas emissions, according to the Intergovernmental Panel on Climate Change (IPCC). The UN climate panel notes that while most estimates are lower, much higher sea level rise cannot be ruled out in more extreme scenarios, potentially approaching 2 meters (6.7 feet) by 2100 under very high emissions scenarios, though these outcomes are considered low-probability, high-impact.

North of Rotterdam, the Afsluitdijk — a 32‑kilometer (20-mile) dam in the northwest — separates the freshwater IJsselmeer lake from the Wadden Sea. It provides water for agriculture and drinking while protecting large parts of the country from flooding. Rising seas and changing climate conditions are increasing pressure on the system, prompting upgrades such as new sluices and expanded pumping capacity at the dam. Dutch authorities say further adjustments, including additional pumping capacity or changes to water-level management, may be needed around 2040.

The Delta Program undergoes a major review every six years, with the latest assessment due in September. Ensuring sufficient funding remains a top priority.

Currently, the Netherlands invests about 1% of its gross domestic product in water defense, but “we need to double our investment,” Verdaas said. In 2026, the Delta Fund will allocate €1.9 billion ($2.2 billion). The total program cost is projected at €38 billion ($43.7 billion) for 2015–2050.

“We are also experimenting,” Verdaas added. Several projects now use natural tides and sediment to strengthen the coastline, by allowing sand, mud, and silt carried by the sea to settle in targeted areas. Over time, this natural buildup raises and reinforces the land, helping protect shorelines while reducing the pressure on dikes and other hard infrastructure.

“So it’s not a contradiction between nature-based or technical solution, but let technical innovations work together with the natural system. That’s the way forward, we think,” Verdaas said.

But threats aren’t limited to the sea. Rivers flowing through the country also pose challenges, especially as melting ice and heavy rainfall increase water levels. The Netherlands’ two main rivers, the Rhine and the Meuse, along with smaller rivers such as the Scheldt, flow across several countries before reaching the Dutch delta, making coordinated management essential. Parts of these rivers lie below sea level, requiring pumps and sluices to actively regulate the flow.

The Netherlands’ Room for the River program allows floodplains to fill with water when high river levels are high, then safely drain when the water recedes. “The floodplains are normally grassland where cows graze. During high water, these places get flooded, cows are evacuated, and when the water recedes, there’s very limited damage,” Verhagen said.

Paradoxically, some areas now also face droughts, prompting initiatives to store water for agriculture and drinking.

“Water is the language of climate change, so most of the impacts we feel come through changes in the water cycle. That’s either too much, too little, or not clean enough water,” Verhagen added.

Dutch cities are innovating to build urban water resilience. Rotterdam, in addition to more than 1,000 pumping stations features green roofs that store water and cool buildings, and public spaces such as Water Square that double as water storage during heavy rainfall.

“Basically, it is a kind of place that is … like, two meters (6.7 feet) below the street level, where if it’s sunny, people play. They play basketball, they play soccer, they have performances, they have church services. But when it rains very hard, it fills up with water,” Verhagen said. Other countries have also adopted this idea.

Rotterdam is also experimenting with floating infrastructure, creating offices, farms and homes resilient to rising sea levels. “You need to make resilience measures multifunctional,” said Verhagen. The Global Center on Adaptation in Rotterdam, where he works, is housed in the world’s largest floating office, a 3,500-square-meter (37,674 square-foot) timber structure that is carbon-neutral and cooled using harbor water.

“Our language is full of, ‘we did conquer the water, we did conquer the elements,’ but now we have to cooperate with them in the new chapter. So that’s quite a shift,” Verdaas said.