The Afsluitdijk, Den Oever, The Netherlands

The 90 year old, 32 kilometer long coastal defence dam 'Afsluitdijk' needs a thorough upgrade to withstand the predicted sea level rise, heavier storms and discharge of large quantities of fresh water to the sea in case of heavy rain fall. [Rijkswaterstaat/The Dutch Government requested] a reinforcement of the dam by raising it with 2 meters to cope with the expected sea level rise and severest storms expected once every 10,000 years

In a Joint Venture called Levvel, BAM Infra Nederland, Van Oord, Rebel and Invesis, DMC plays a key role in the design team. We perform the Tender Design, Basic Design and Detailed Design for the defence dam strengthening, road works and all new civil structures.  Our [coastal solution] for the dam reinforcement is the installment of 75,000 sustainable, unique concrete armour blocs XblocPlus (on this project called Levvelblocs) at both sides of the dam for wave protection, resulting in a smooth surface in line with the architectonic requirements of the dam. 


Due to the expected sea level rise, the discharge capacity of the sluices need to decrease. Therefore we choose to design six of Europe's largest solar powered, fish friendly pumps in two seperate pumping stations with a total pumping capacity of 253 m3/s. The idea behind our design is to save as much energy as possible with our premise: Discharging water when possible, pumping water when necessary. 

The strengthening and renovation of the 90 year's old sluices, which are listed National Monuments, require a delicate balance between structural and hydraulic capacity and its heritage values. The new pumping and sluicing structures are aligned near the Monuments, necessitating a close cooperation between the project's Architect and heritage consultants. We equipped the two exisiting ship locks with a new movable flood defence barrier, each weighing 1 million kilograms measuring 58 meters in length and 14 meters in height. 

A unique fish migration river

We designed a 5 kilometer long artificial fish passage river through the dam to enable fish to freely swim between the sea and the lake.

If you wish to learn more about this project or on questions you have regarding coastal protection, please contact Bas Reedijk, Head of Coastal Engineering Department at DMC:

Facts and Figures

IJsselmeer, The Netherlands

Coastal Defence Dam


Our client

BAM, Van Oord, Rebel (Levvel JV)

Completion design

Re-inforcementof 90 year old Coastal Defence Damto withstand predicted sea level rise, heavier storms and discharge of  large quantities of fresh water to the sea in case of heavy rain fall.

Design and construct XblocPlus, new pumpstation and fish migration river.