Maeslant Barrier

No other flood barrier in the world has larger moveable parts than the Maeslant Barrier. This part of the Delta Works can withstand a storm tide of 5 m above NAP.

The Maeslant Barrier is located in the Nieuwe Waterweg near Hook of Holland and was built between 1991 and 1997. The structure is operated entirely automatically and, together with the Hartel Barrier and the expanded Rozenburg dyke, forms the Europoort Barrier. The Maeslant Barrier is a forward flood surge barrier, which means that it receives the full brunt of flooding from the sea and so protects the residents of the province of Zuid-Holland.

Facts and figures Maeslant Barrier

210 m

is the width of each door of the Maeslant storm surge barrier

The Maeslant Barrier:

  • was closed for the first time in 2007;
  • has 2 doors, each 210 m wide, 22 m high and 15 m deep. When the barrier closes, they fill with water and sink to the bottom within 2 hours;
  • operates with ball-and-socket joints, each of which is 10 m in diameter and weighs 680 tonnes.


The Maeslant Barrier was not a part of the original Delta Plan, but its design is just as ingenious and massive as the other structures in the Delta Works. Prior to its construction, an independent committee in close consultation with Rijkswaterstaat, the municipality of Rotterdam and the water board investigated four variants. The committee assessed the duration the design would take to build, the costs and the consequences for the business community. It also assessed which variant would blend most effectively into the landscape.

Tasks of Rijkswaterstaat

Rijkswaterstaat manages and maintains the Maeslant Barrier. Using a specially developed model we carry out analyses to calculate the risk that the barrier will refuse to close and test, inspect, repair and if necessary replace parts on the basis of those calculations.

The Maeslant Barrier closes fully automatically

Closure of the barrier

The Maeslant Barrier closes if the water level is predicted to rise to more than 3 m above NAP near Rotterdam or more than 2,9 m above NAP near Dordrecht. The closure of the barrier and the decision to close it both occur fully automatically. In principle, no human intervention is required. Nevertheless, if flooding is expected, an operational team from Rijkswaterstaat is always on hand to monitor the automatic process and to intervene manually if necessary.

Plan your visit to the Maeslant Barrier

Would you like to learn more about the Maeslant Barrier and see the flood barrier ‘in real life'? The Keringhuis Water Management Information Centre has a host of information on flood protection and the Maeslant Barrier itself. From the Keringhuis, you have a panoramic view of the immense structure and you can learn all there is to know about it.

It is also interesting to pay a visit to the Watersnoodmuseum at Ouwerkerk, the museum dedicated to the North Sea flood of 1953. Learn more about those events, the Delta Works, dyke reinforcement and repair work.