April 2005

The Netherlands

A country that engineered itself into existence is tapping into its centuries-old expertise in handling water.

By Erwin van den Brink

December's deadly tsunami in the Indian Ocean drove home how vulnerable low coastal areas are to the forces of nature. In the Netherlands, which carved itself out of the ocean centuries ago—and a quarter of whose land mass is below sea level, while two-thirds is vulnerable to flooding—the mastery of coastal waters remains the object of much technological innovation.

The Dutch acquired their hydraulic expertise partly in response to disaster. In 1953, a number of sea dikes in the southwestern part of the country gave way under a tidal surge. The disaster, which killed about 1,800 people, spurred one of the largest hydraulic projects in the country's history: the Delta Works. Almost all of the inlets and estuaries in the southwestern part of the country were closed off by a system of dams and storm surge barriers. One of the two main arteries remaining open—the estuary near Rotterdam—was fitted with the most massive movable storm surge barrier ever built. Known as the Maeslant Barrier, it has an automated control system that closes its giant doors based on real-time weather information, which can indicate the ­approach of a spring tide. The system's software borrows from a branch of ­mathe­matics called formal methods; its performance is continually monitored, and improvements are made as knowledge of weather behavior progresses.

Were Holland's dikes, dams, and pumping stations ever to fail again as they did in 1953, a densely populated, 150-by-150-kilometer area would suffer from a catastrophic flood. Bas Jonkman, a civil engineer with the Dutch Ministry of Transport, Public Works, and Water Management, and Nathalie Asselman, a researcher with Delft Hydraulics, recently simulated a dike breach near the Dutch town of Capelle aan den IJssel. According to their simulation, in the worst-case scenario, the water in the village could rise five or six meters in a matter of hours, killing about 72,000 people.

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To help prevent such tragedies, the Netherlands has computerized most every aspect of sea defense management. ­Institutions such as Delft University of Technology, UNESCO-IHE In­stitute for Water Education, WL/Delft Hydraulics, and the technology development consultancy TNO run computer models that simulate the reaction of water and sediments to human interference. Those simulations are used to estimate the effects of such megaprojects as building an airport on an artificial island in the North Sea or creating thousands of acres of new land near the coast—indeed, for almost any civil-engineering project.

Weather and climate systems, like shifting sediments and the currents of rivers and seas, are impossible to describe accurately using linear models. Research by Dutch mathematicians on nonlinear systems has produced computer models of these phenomena that are of vital importance to the country's survival. Thanks to these models, the pumping stations that keep the Dutch lowlands from flooding can anticipate prolonged rain spells, and mechanical storm-surge barriers can be closed in time when massive storms approach.

Dutch engineering has focused on not just controlling the flow of water but also keeping it clean. The drinking-water chain in the Netherlands is a fully closed system: sewage water is treated so that it can be safely discharged into surface water. The purification of drinking water has recently come to rely on new, environmentally friendly techniques: using ultramembranes and ultraviolet light to kill bacteria. Ultramembranes, with pores so fine that they can physically screen individual cells, have gained wide adoption over the past five to 10 years. Ultraviolet technology developed by Dutch engineering companies such as DHV is commonly used in the "after-disinfection" stage of water treatment, as a second level of defense. However, the Dutch water company PWN has begun employing UV light during the entire disinfection process. PWN's technique uses a photochemical process to create powerful oxidizers, which break down organic compounds so that they can be consumed by aerobic bacteria that reside in active carbon filters. According to Peer Kamp, head of innovation at PWN, the next challenge will be the removal of all traces of pharmaceutical drugs from water.

Dairy and meat products, along with flowers, make up 20 percent of Dutch exports. And the agricultural and food-processing industries are becoming more entwined with the pharmaceutical industry. A few years ago, for example, the Dutch-British firm Unilever launched the product line Becel pro.activ (marketed in other countries under the name Flora), which helps people control their cholesterol. Ultimately, such "functional foods" could help to prevent heart disease and perhaps diabetes. Dutch tech­nology, here as in its massive feats of environmental engineering, aims to keep people safe.

Ervin van den Brink is editor of Technology Review's Netherlands edition.