On the day of his country's demise, Don Berghuis is wearing the colors of the Dutch royal family -- in the form of an orange fleece jacket over his dress shirt. And that's a good thing, because this man, with his silver-hair, is a patriotic fellow. On this morning he is being called upon to prove that he can save the Netherlands.

At five minutes to nine, a red dot lights up on the map on a giant wall monitor. "PL 24 isn't going to last much longer," says Berghuis. PL stands for polder, the rectangular sections of earth that the Dutch have laboriously wrested from the sea. "Vertical evacuation?" Berghuis asks the group of people assembled around a table at the crisis center in the city of Utrecht. Everyone knows what he means: Can local residents save themselves by climbing onto their roofs?

"No," mutters a major in combat gear. Who wants to rescue 200,000 people from the roofs, using helicopters? And Berghuis knows that the water will not disappear overnight. In fact, the experts from the country's water authority have told him that it will take an entire year to pump the area dry once again.

"The people need to get out," he says calmly. "Notify the media," he tells his deputy, adding: "Now there is no turning back."

The Netherlands' emergency preparedness personnel spent all of last week conducting an exercise dubbed "Ergst Denkbare Overstroming (EDO)," or worst possible flooding, a scenario in which they virtually placed one-third of the country underwater. In the computer models, the entire west and north coasts, as well as low-lying areas in the large Rhine River delta where two-thirds of the country's 17 million people live were submerged.

The scenario spells pure horror for the Dutch. Just in time for the spring tide, under a full moon, a giant low-pressure zone with force 11 to 12 winds (wind speeds of 64 to more than 73 miles per hour) rolls in from the North Sea. The storm surge pushes five-and-a-half-meter (18-foot) waves against storm barriers along the coast. But the elements have even more in store for the unfortunate Dutch. There is a thaw in the Alps, and it has been raining heavily in Germany for days. The Rhine River is carrying 16,000 cubic meters (4.2 million gallons) of water across the German-Dutch border -- every second.

The experts have calculated that this scenario is likely to occur once every 4,000 years. "But what good is this number to us? It could happen in a week," says Berghuis, "and that's why we would rather be prepared." The Dutch authorities have never conducted such a carefully planned "calamity" exercise -- and it comes only after two years of preparations and with a cost to the Dutch government of €15 million ($19 million).

The interior minister in The Hague has selected Berghuis to coordinate emergency management should such a dramatic situation occur. In the garden next to the situation center outside Utrecht, the military has erected a small tent city with its own command center. "In an emergency, we will be living in close quarters," explains Major Wouter Boon. The disaster planners reason that if flooding destroys the country's communication networks, it will be a good idea to have military units stationed near emergency management centers.

Berghuis has already ordered the evacuation of Flevoland Province in the center of the country, but now the situation has deteriorated even further. Dikes are rupturing throughout the country, the water is flooding various overflow spillways and the pumps are no longer capable of handling the massive volumes of incoming water. A lower-ranking officer hands Major Boon a list with two numbers on it: 1,941,013 and 6,441,109 -- the populations of the two coastal regions currently affected by the flood. Boon issues an order to close the A12, a major highway bisecting the country, to all traffic heading from the safe East to the flooded West.

"Many people are staying with friends and relatives at higher elevations," says Boon. Tens of thousands are forced to move to emergency shelters in gymnasiums, schools and parking garages. Will they remain calm as they flee the rising waters, or will it be sheer chaos? Boon has no illusions. "The people will be horrified by what they see." There will be dead people floating in the brackish water, joined by even more dead animals -- a million cows, chickens and pigs in Flevoland alone.

In a retirement home in Leerdam, soldiers and emergency relief workers are practicing the orderly evacuation of those frail citizens who are a nightmare for any emergency management professional. Cees van der Flier, for example, is bed-ridden, confused and incontinent -- or at least that is what he and two dozen other volunteers are pretending to be. "I have a degree in disaster victimhood," says the retiree, with a smirk, only to begin grumbling as a medic rushes his way.

The evacuation is still not working the way it should. After 20 years of participating in these disaster simulation exercises, he has enough experience to know what is going wrong. In today's mock disaster, he says, he hasn't been given his medication. As a result, he is hallucinating more than usual. Later on, in the "De Dak" party center, the safe haven where he has been taken, van der Flier talks about the storm surge, on Feb. 1, 1953, in which more than 1,800 people drowned. He was nine years old at the time, when he and his father and grandfather climbed to safety on the roof of their house in Oude Tonge in Zeeland Province. "Dead cows were floating by," he says, sipping his coffee, "I can still see the images before my eyes."

The flood became deeply embedded in the collective memory of the Dutch. The vulnerability of this prosperous nation, much of it located below sea level, depends on the technical skills of its hydraulic engineers, and their expertise will be in even greater demand in the future. "Back then the flood was two-and-a-half meters high," says Lucien van Hove, "today we assume it could be above five meters." Van Hove, the coordinator of the giant storm barriers in the delta region around Rotterdam, is standing on the first line of defense against the great storm surge, the barrier gates in the Hollandse Ijssel, a branch of the Rhine delta. Each of two enormous steel gates is 81 meters (265 feet) wide and almost 12 meters (39 feet) high. At this moment in the simulation, they are virtually closed.

The storm barrier is designed to withstand a 70-centimeter (2.3-foot) rise in sea level. But two months ago a commission concluded that a rise of 1.30 meters (4.3 feet) could be expected by the year 2100. "We must now invest a part of our gross national product each year so that we can keep our feet dry in the future," warns van Hove. New storm barriers are needed, he says, and the dikes must be raised and, more importantly, widened. In addition to the problems posed by climate change, the land is sinking by two centimeters (three-quarters of an inch) each year, for tectonic reasons and because the subsoil, which contains peat and clay, is drying out.