Preventing a Dutch dike from breaching

Efficiently fortifying flood defence

Imagine... you're a country. A densely populated one. You have major rivers like the Rhine and the Meuse flowing through you, you have Europe's biggest lake, and you have the North Sea lurking right beside you. And you are below sea level. What do you do?

That's right, you protect yourself, the best you can. That's what they have always done in the Netherlands, a country well-known for its dikes and dams. Without them, about half the country would be flooded.

Five kilometers

Since flood defence is so vital, these dikes and dams are thoroughly inspected regularly. Sometimes, it turns out there's work to be done.

This was the case recently in Lemmer, a small town in the province of Friesland, where the Zeedijk (Sea dike) appeared to require an extreme make-over. It's situated near the IJsselmeer, the big lake we just mentioned.

“An important part of this dike did not pass the inspection. Five kilometers of it did not meet the current guidelines,” says Jan Anne van der Meer, director of Van der Meer BV. It's up to his earthmoving and contracting company to renew the Zeedijk and make the surrounding residents feel safe again.

Arrive, drop, return

“The project has been divided into three sections which we have to take care of in three years. We are allowed to work on it from April 1st to October 1st, outside the storm season.”

With the supply route consisting of just one long road, and 40 trucks required to transport 3000 cubic metres of clay a day, this was a project to chew on at first. The company wanted to enable its truck drivers to arrive, drop, and return to get more clay – all without being delayed.

“Logistically, that was a challenge. It turned out to be a bit of a puzzle, but we figured it out,” says Van der Meer, who has every right to be proud they did.

“And now we are ahead of schedule. We were supposed to start tackling the third section this year, but we've already taken care of 300 meters of it. Now you may think '300 meters, that doesn't seem to be all that much', but it comes down to about 25.000 cubic meters of clay that has to be moved.”

Quite the difference

To raise and reinforce the Zeedijk in Lemmer, Van der Meer BV works with bulldozers and excavators that are equipped with Topcon's machine control systems.

The systems allow Van der Meer BV to build the new embankment with exactly the right measurements. The excavators work with a margin of only 2 centimeters. And their operators hardly have to leave their cabin to do their work.

“The display provides the operator with all the information he needs. In the old days, you had to spend much more time surveying, making measurements, placing pegs to mark boundaries. Now, we make a 3D model of what the situation is intended to be like, we upload it and it's right there, always at hand. That's quite the difference.” says Van der Meer, adding that it's a time-saver.

“And the system on the bulldozers is helpful as well. If you drive onto the dike diagonally, it adjusts itself and makes sure the blade is correct anyway.”

Impressive work by Van der Meer BV. As they go into the third and final year of the project, residents of Lemmer can rest assured: the Zeedijk will effectively protect them again soon.