Keeping Holland Above Water: The Facts Behind the Epic Struggle



THE Dutchman, in his everyday language, is always reacting in terms of water. He does not fire away with a story but “pushes off.” If he makes the best of things, he “rows with the oars he happens to have.” His boss does not give him the sack but “kicks him out on the dike,”and if he gets an hourly paid job, he says, “This puts no sods upon the dike.” When he starts doing well, he speaks of going “straight through the sea” instead of “letting God’s water run across God’s acre” as he did before.

The Dutch, as a nation, have water on the mind, simply because six million out of ten million Hollanders live below the level of the sea or bandy above it, only separated from the angry surf and the whirling tides in the broad estuaries by great dikes and shifting sand dunes.

During the night of February first, 1953, the sea, in a furious onslaught, tore more than 300 gaps in these dikes. Between seven and eight per cent of Holland’s arable surface, about 630,000 acres, were flooded by salt and brackish water. More than 1,400 people and 25,000 cows were drowned. Once more the Dutch were reminded of the warning words, written some 400 years ago by the master dikebuilder Andries Vierlingh, “ For your enemy Oceanus, day and night, rests not nor sleeps, but comes like a roaring lion seeking to destroy all that lies round about.”

The 1953 floods were the greatest catastrophe since November 1421, when the sea wiped out 72 villages and their 50,000 inhabitants in one night. But at that time the Dutch could only defend themselves with spades. Today they excel in modern hydraulic engineering. How then was it possible that such a water-wise people let themselves be surprised in their sleep? How did this disaster come about? And what are the Dutch going to do now to avoid a tragic repetition?

Dutch history is a long tale of land that became water and water that became land again; it is the fighting story of a nation forever besieged and assaulted by the sea. Ten centuries ago the low western half of what is now called the Netherlands still was a vast swamp behind a narrow belt of dunes. The somewhat higher eastern half consisted of heath and sand and low pine forests. The swamp was originally part of an enormous moor running from the Straits of Dover to Denmark. It consisted of a deep layer of peat floating on water with a layer of fertile clay underneath. In the eastern half of the country, medieval Dutchmen burned wood in their hearths; but in the western half they dug out the peat, dried the lumps, each big as a loaf of bread, in the sun and used this “turf” as fuel. In this way they created new fresh-water lakes, apart from the many already existing.

The dune belt could only protect the low country where the dunes were sufficiently high, Two thousand years ago the sea had already broken up this sand barrier in the north, thus creating the present Frisian islands, and in the south, where the outlets of the rivers Rhine, Meuse, and Schelde were subsequently widened and deepened by the everscouring tides. Look at the map and see the result: an archipelago of some dozen islands, with deep estuaries in between. The westernmost island is Walcheren, standing like a square fortress at the mouth of the Schelde estuary which in places reaches a depth of some 200 feet.

During the thirteenth, fourteenth and fifteenth centuries the seas, in a dangerous pincer movement, almost succeeded in wiping out that part of the low plain called Holland proper. Around 1300, a high stormflood broke through the north to the largest fresh-water lake in the center of the whole country, and widened and deepened it until the Zuider Zee came into existence; Amsterdam, then a small town of fishermen, grew into a seaport. During the St. Elizabeth’s flood of 1421 the sea, attacking from the south, drowned the country below Dordrecht and threatened Rotterdam. The remainder of the hydrological story of Holland is the chronicle of a patient and sometimes glorious fight against this pincer movement of the encroaching waters.


FIRST of all the Dutch, attacking along the line of least resistance, fought the “fifth column” within the walls of their dike fortress. With the help of the newly invented windmill, they pumped the largest sweet-water lakes dry. These were dangerous, for whenever a storm blew up they hurled their spray at the houses on shore and tirelessly nibbled away at the narrow stretches of dry Land between one lake and another. In this way the great Haarlem Lake got the name of “Water Wolf.” Today, plumb in the middle of this erstwhile lake, is Amsterdam’s Schiphol Air Field. All around stretches a pancakoflat country bearing the heaviest wheat crops in the world. As lake after lake was thus turned into fertile clay, some witty and admiring Frenchman invented the classic saying: “God made the earth, but the Dutch made Holland.”

In Holland, a passion for peaceful conquest has grown with the centuries: to create laud out of water; to paint green, bit by bit, what is blue on the map; to grow grain where fish have swum; to ride horses where the monotonous waves have marched. But it took the individualistic Dutch several centuries before they succeeded in converting their piecemeal defense into large-scale attack.

“He who suffers the sea’s attack, must himself push the water back,” runs an old Dutch proverb. Each man originally was only responsible for the dike which rose around his horizon. Only in the nineteenth century did the Royal Government, imposing its will upon short-sighted towns and obstinate polder1 Boards, organize the famous corps of hydrological specialists called “ Waterstaat.” Henceforth not a drop of water poured into Holland, through Holland, or against Holland without the Waterstaat’s knowledge. The engineers, before counter-attacking against the water’s savage onslaught, minutely studied the method in its madness.

Around 1890, a Waterstaat engineer called Herman Lely one day took a pencil and drew a line straight across the narrowest part of the large inland sea, the Zuider Zee. Forty years later the place of the pencil mark was taken by a dike twenty miles long. But it was only after thirty years of slow deliberation and nine more years of careful planning that the first sand blower started work, some time after a bad flood had engulfed several of the Zuider Zee towns. Until then, spades and wheelbarrows had been the main implements for building a dike. Now the clay-grubbing polder worker was assisted for the first time by a marvelous piece of modern machinery: the floating steam crane, which, with every swing of its 100-foot arm, dug three tons of tough clay out of a barge alongside, and tossed them into the foaming waters.

On the Zuider Zee job, the Waterstaat engineers learned a costly lesson. When the dike heads drew together, both ebb and flood tide started running wild as they reeled through the narrow gap of a few hundred yards. When the tide ebbed, the surface water in the Zuider Zee, fifty miles long and thirty miles wide, tried to rush out all at once. The water that could not get through hammered against the dike heads, was flung back upon the pursuing masses of water, and then began to whirl in deep eddies that reached clear to the bottom and played havoc with the bottom protection, consisting of thick mattresses of woven brushwood on which hundreds of tons of heavy stones had been pitched. The eddying water sucked the sand straight through the mattresses which then suddenly collapsed into terrifying holes. Often they imperiled the whole work.

But the Zuider Zee dike was successfully closed in 1932. Sheltered by this new sea wall, and in tideless water, further dikes could now be built around five enormous new polders. Two of these are ready today; the last one will be completed by 1970. The remaining water surface will serve as a storage basin for the amount of rain water that during the long wet seasons is pumped out of the polders, and for the outflow of the river Ijssel, a branch of the Rhine.

A great victory had been won. At one blow the Dutch coastline had been shortened from 1,150 to 840 miles. The dangerous tidal pincer movement against Holland’s central plain had been defeated. The northern claw of the ever-threatening sea had been hurled back some sixty miles.

And it was high time too. Dutch scientists had previously come to the alarming conclusion that during the last century the whole of Holland had sunk one foot in relation to the mean water level of the North Sea. Man could fight the sea but he was powerless against its ally: a relentless geological phenomenon that was sucking Holland downward. The causes were various and equally interesting. First of all, the whole of the North Sea Basin has for the last 200 million years been sinking, very, very slowly, while for the last 20,000 years the water level of the North Sea has been rising, equally slowly, because the great ice cap that once covered the whole of Northern Europe has been melting off gradually. Moreover, during the last hundred years or so the glaciers in Scandinavia and the Alps have melted much faster, so that the water level of the North Sea has risen more rapidly. The third phenomenon is downright eerie. Ever since Scandinavia has shaken off its heavy ice cap, the whole peninsula has been veering upwards at a rate which, in some places, reaches 0.4 inch a year. The surface of Holland, situated at the other end of an enormous invisible see-saw, is tilting downwards at a corresponding rate, while Denmark, right above the fulcrum, remains stable.


KEEPING Holland above water during the coming centuries means that all sea dikes will have to be heightened and strengthened. It is therefore essential to try to shorten the coastline still more, especially in the southwest, where the tidal waters are penetrating deep inland. Moreover, the Waterstaat engineers came to the conclusion quite some time back that the old sea dikes around most of the islands in the Zeeland archipelago would not be able to withstand the impact of the severest conceivable gale. The engineers calculated, however, that the three weapons in the sea’s dark armory—tide effect, wind effect, and wave effect—could only combine their maximum forces once in every 1,260 years. So the Dutch islanders just put their trust in God and their dikes, while the engineers debated whether it would be better to heighten the existing dikes (an enormous job) or to try to dam the estuaries—a still vaster job, fraught with partly unknown dangers.

For the slowly sinking land is attracting more and more water, mainly from the Rhine and Meuse, which can only escape into the sea through estuaries if the ebb is pulling away outside, and if the adverse wind effect is not too strong. During an abnormally rainy and stormy winter the frustrated waters of the Rhine and Meuse, already swollen with rain water pumped out of the polders, could reach a level as yet unknown and threaten to breach the up-river dikes, unless these were also heightened — another enormous job. Closing most of the estuaries would certainly keep the sea out for good but it might also create a fresh water threat from within.

All these calculations and deliberations were cold comfort to the wretched people clinging by hundreds to farm roofs and trees during the night of February first, last year. And the Dutch now realize, with deep anxiety, that this disaster can occur again. The modern dikes, built to withstand the worst combination of tide, wave, and wind effects, held their own; most of the older ones went to pieces, being a shade too low for twentieth-century conditions: the land moving downwards, the sea rising slightly, the perpetual scour of the tides ever deepening the estuaries, so that during a gale the ground swell could multiply its devastating force.

The direct causes of the disaster have now pretty well been analyzed. For some days the wind had blown briskly from the southwest, piling up the water more and more in the northern part of the North Sea. On Saturday night, February first, the spring tide was already somewhat past its peak, otherwise the disaster would have been still worse. But the wind abruptly swung around from southwest to northwest, and all the piled-up water was suddenly blown down towards the narrow funnel of the English channel. It could not pour off fast enough and so rose up against the English, Dutch and Belgian coasts in long, surging swells. The English coast got the glancing blows, the Dutch coast the direct hits. The wind force averaged 65 miles an hour for some 20 hours, with hurricane gusts reaching a velocity of 95 miles during the hours of full flood. It was not so much the spring tide as the combined effect of waves and wind that played havoc with the dikes. The hurricane tore the statistics for the last hundred years into shreds. The waves arched in long, angry sweeps over the crown of the dikes, and the water just swallowed them from behind, sucking away at the sods and drilling holes into the clay covering underneath, through which the sand body then streamed away. The batteringram of the wind-driven waves kept pounding against the stone facing on the sea side. Its back broken, the strong sea wall suddenly gave way.

As this is written all the breaches have been closed again. But immediately after the disaster a debate started raging. Should the battered sea walls in the southwestern archipelago be heightened or should an attempt be made to close the estuaries, with the exception of the Western Schelde, which gives access to Antwerp Harbor, and of the direct waterwayleading to Rotterdam? This would mean another shortening of the Dutch coastline from some 800 to barely 300 miles: an enormous difference in cost of dike upkeep!

Agricultural experts, moreover, had been stressing for years what many farmers already knew from experience: far too much salt tidewater was penetrating far up-river. Apart from seeping stealthily through the dikes into the polders, it got directly into the inland water system. It would eventually poison some of the best parts of the arable land.

Strangely enough, this whole debate would have been useless some ten years ago. Before World War II, damming the broadest sea mouths seemed an impossible feat: the currents were just too fierce, the gullies far too deep. Imagine building a dam across seventy Colorado rivers side by side. Boulder Dam was built on dry ground, because the Colorado River had first been diverted through tunnels which bypassed the site of the future dam. But there is no way of diverting a tidal estuary ten miles broad. Holland must contrive to build where no nation on earth has built: under water, on a sand bottom forever in motion. The problem had partly been solved: the shifting sand could be fixed by sinking large brushwood mattresses and covering them with deep layers of pitching stone. On this bottom protection, clay dams could be built by floating cranes in water not too deep. But as the dike heads grew together and reached the rim of the deepest gullies, a current racing along at some 20 feet a second would just carry away brushwood mattresses, clay, and stone like so many straws. In 1667 the Dutch water wizard Simon Stevin had already advocated this idea, and 275 years later it seemed as far from being realized as ever. In a wholly unexpected way World War II brought the solution.

In order to free the access to the Schelde and to Antwerp, British bombers, during November 1944, breached the sea dikes of the heavily fortified island of Walcheren where the tides run fiercer than anywhere along our coast. The Westkapelle sea wall, a whale of a dike, measuring 330 feet across and rising to 30 feet above mean water level, had to be bombed twice before its hinterland could be drowned. Right on the heels of the liberating Allied armies, the Dutch Waterstaat smuggled itself into this military territory in the person of Chief Engineer Peter Philip Jansen. He surveyed the four most terrible dike breaches ever made, and solemnly created the “Waleheren Drainage Division.” It consisted of eight men, who started operations on the war-torn island with twelve shovels, two wrenches and a leaky rowboat. Right from the start it was a fight against time: engineer Jansen had calculated that the gaps had to be closed within a year, before the gales of another winter could scour out the gullies behind the breaches to such an extent that they would cut the island to pieces.

Soon after all of Holland was liberated, the biggest Dutch dredging fleet of all time sailed down the troubled waters of the Schelde to save Waleheren from the clutch of the sea. Engineer Jansen had realized from the beginning that the final gaps, with their swift tide currents, could only be closed in one swift operation, Late in the summer he finally got what he had asked for during the last war winter: the steel and concrete caissons which had served as breakwaters and pier supports in the artificial harbors outside the D-Day beaches. Here he had trouble with the stubbornness of the old-fashioned Dutch contractors. But the biggest foe of the “newfangled nonsense,” contractor Kobus Kalis, became its staunchest champion once he had seen that his dearly beloved clay was carried away by the swiftly moving sand. The most dangerous breach, near Flushing, was closed by anchoring a dozen small caissons in the final gap. They were sunk and then ballasted with clay, which also plugged up the remaining rifts. Ten days later a gale smashed the new dike, and washed out the bottom protection of brushwood mattresses. Without this foundation all new attempts were doomed to end in disaster; at least that’s what the older engineers thought. But the younger engineers took over, and worked out a daring scheme proposed by Major Allan Beckett of the British Royal Engineers. They scrapped the wisdom of their forefathers and sunk a big cement caisson right outside the gap, on the exposed seaside. Then the floating crane hurled hundreds of tons of steel anti-torpedo nets into the remaining gullies. Gradually the barricade of heavy steel rings broke the force of the current, Kobus Kalis, who will go down into hydrological history as the Paul Bunyan of Dutch dike building, directed the job for three days and nights without a wink of sleep. Then, when the waters were again standing still, he went home and breakfasted on three roast ducks and half a bottle of Dutch gin.

A crucial battle had been won. A gully, twenty feet deep, through which a current was raging that would have swept away all the classic materials of Dutch dike construction, had been plugged up mainly with concrete and steel. Dutch dike building had taken a great stride forward. That same day the Westkapelle breach was blocked, as a virtual wall of cement slid into the final gap. In the most wicked gap of all, east of Flushing, two enormous caissons, big as apartment houses, and a few dozen smaller ones, finally did the trick after five more months of bitter struggle.

The fifteen-month fight for Walcheren was the greatest adventure of Dutch hydraulic engineering. It was an improvisation from beginning to end. But the new weapons first tried out at Waleheren haw since been perfected. Engineer Peter Jansen, now professor at Delft Technical University, declared in his inaugural speech that it is now possible to close a final gap in one of the sea mouths by sinking simultaneously two concrete caissons 200 feet long and of 3,000 tons displacement each.

Against the water, attack is the best defense. A board of specialists is at present studying all the problems involved in the closing of the estuaries, which still endanger our national safety. It is the boldest dream of Dutch hydraulic engineering. The job may take 25 years and cost a billion guilders (almost 300 million dollars); but last year’s great flood cost us at least as much, apart from the toll in human lives. And behind the new and shorter sea walls, much new land can be won. New harvests will be reaped where waves have been running.

  1. Polder: a tract of low land reclaimed from the sea by dikes.