The Afsluitdijk, Den Oever, The Netherlands

We are all facing a rising sea level and an increasing intensity of storms and floods. Especially our country, The Netherlands, with large parts of land belows sea level. For this reason, the Dutch Government is currently executing large projects to keep The Netherlands safe. One of the projects is the reinforcement of the major coastal defence dam Afsluitdijk, which was originally opened in 1932. As DMC we are proud to have a key role in the design team, providing sustainable and innovative solutions to protect us against water.

Reinforcing 32 kilometer long coastal defence dam

The coastal defence dam 'Afsluitdijk' reduces flooding risk for a large part of North Netherlands. The Afsluitdijk is currently undergoing a thorough upgrade to be able to withstand the predicted sea level rise, heavier storms and to enable discharging large quantities of fresh water to the sea in case of heavy rain fall.  Throughout the reinforcement works, the dam can remain open for heavy traffic and its current flood protection function remains maintained. 

75,000 sustainable blocs

After completion of the reinforcement, the dam will be about 2m higher to cope with the expected sea level rise and severest storms expected once every 10,000 years.

75,000 sustainable concrete armour blocs (XblocPlus, on this project called Levvelblocs) are installed at the seaside of the dam for wave protection. The lake side is strengthened as well. 

5 kilometer long fish migration river

For the importance of ecology, a unique 5 kilometer long artificial fish passage river through the dam is being built to enable fish to freely swim between the sea and the lake. 

Discharging water when possible, pumping water when necessary

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

National Monument

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. 

Furthermore, the new pumping and sluicing structures have been aligned near the Monuments, necessitating a close cooperation between the project's Architect and heritage consultants. 

The two exisiting ship locks are equipped with a new movable flood defence barrier, each weighing 1 million kilograms measuring 58 meters in length and 14 meters in height.

To allow vessels to always use one of the locks during the works, the two doors are placed (see photo).

Role of Delta Marine Consultants

DMC performed the Tender Design, Basic Design and Detailed Design within a Joint Venture with BAM Infra Nederland, Van Oord, Rebel and Invesis for the defence dam strengthening, road works and all new civil structures. 

If you wish to receice more information on this project or on questions you have regarding water protection, please contact Martijn Meijer, Head of Maritime Structures Department at DMC: martijn.meijer@dmc.nl