57 meters long, 14 meters high and 7 meters wide: this is the size of the roller door that is being installed today at the Afsluitdijk. The colossus is part of a flood lock, which should better protect the hinterland against high water.
The floodgate will be located in the Wadden Sea near Kornwerderzand, on the Frisian side of the Afsluitdijk. Until now there were only locks here, the well-known locks through which ships can sail from one water level to another.
Now a flood lock is being added because the Afsluitdijk was rejected in 2006. The dike did not meet the requirements of the Water Act and no longer offered sufficient protection against high water, says Bram Beijer, technical project leader at Rijkswaterstaat, in the NOS Radio 1 Journaal. “Partly due to sea level rise.”
The roller door will usually be hidden in the dike. But when the water reaches a level of 1.8 meters above NAP, the door closes. “It closes about five times a year,” estimates Beijer.
The colossus will be placed today. See how that goes:

The roller door weighs almost a million kilograms. That is why an 80-metre high floating crane was brought from the port of Rotterdam to Kornwerderzand especially for the installation.
The crane hoisted the roller door into the air around 08:00 this morning and then lowered it into the water at the right place. Now the door still has to be pulled aside, so that the waterway will be clear again. The roller door will probably be in the right place at the end of the day, says Beijer.
The project leader calls the operation “challenging” and “a bit exciting”, due to the enormous size of the door. “It is centimeter work: the deviation from the design may ultimately only be 30 centimeters.”
The floodgate will be taken into use in January 2024. Until then, Rijkswaterstaat will carry out many tests. “But it is also safe at the moment,” says Beijer. “The flood barrier now runs over the existing lock, so we don’t have to worry.”
Since the flood disaster in 1953, our country has been protected against high water with unique Delta Works. This special from NOS op 3 shows how the Netherlands lives with water:
- Largest sea lock in the world opened in IJmuiden: ‘A piece of Dutch glory’
- The freshwater tap will continue to open for the western part of the Netherlands
- Measures against high water have averted disaster, ‘but more needs to be done’
- Can the rain of recent days prevent drought in the summer?
- ‘Rijk did not take climate goals into account when building sea locks’