1891

Zuiderzee Works

Cornelius Lely (1854–1929)

From an engineering perspective, the Netherlands is a fascinating country. It has extremely high human density (over 1,200 people per square mile), about 15 times greater than the density of the United States. Because of this density, combined with its location, the country has been reclaiming new land from the sea with dikes for many centuries. Approximately a quarter of the country lies below sea level—some as much as 23 feet (7 meters) below. And approximately half of the country is barely above sea level. To drive the point home, the word Netherlands means “lowlands.”

On a typical day, the sea remains on its side of the dikes. But when storm surges occur, problems arise. And in a country where much of the land is below or at sea level, storm surges can be catastrophic.

So the Netherlands has invested heavily in protection against storm surges. The Zuiderzee Works consists of dozens of different projects: dams, dikes, gates, and so on. Built based on an original plan by civil engineer Cornelius Lely in 1891, construction did not begin until 1920, and continued through 1986.

Of those works, the most impressively engineered by far is a gigantic, movable storm surge barrier across the mouth of the Rhine River as it exits to the sea. Most of the time, the two parts of the barrier sit on land in dry docks on both sides of the river. The river there is 1,180 feet (360 meters) wide. When a storm surge is expected, the dry docks flood. The two barriers, which float, come out into the river and meet in the middle. Then they submerge to seal the mouth of the river against storm surge arriving from the sea.

Given that the barriers are closing off a river, won’t water back up behind them? It can happen. So the gates can partially refloat to let excess river water flow underneath.

If you think about the size of these barriers, you realize they are some of the biggest moving objects on Earth. The fact that they can move both horizontally and vertically means they have two of the largest ball and socket joints on Earth as well.

Storm surge is a huge problem for the Netherlands, and engineers have risen to the occasion with this moveable barrier.

SEE ALSO Hoover Dam (1936), Venice Flood System (2016).

Northern half of the Maeslantkering, a storm surge barrier in the Nieuwe Waterweg near Rotterdam and Hook of Holland in the Netherlands.