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Dieren en planten

Water en land

Mens en Milieu

Coastal protection   Breakwaters   
Breakwater, De Noordwester

Breakwaters

Breakwaters are small dams which are laid down perpendicular to the coast for preventing erosion of the beach sand and for promoting deposition of sea sand. Approximately one third of the Dutch dune coast is provided with breakwaters. Together with dikes, breakwaters are the 'rocks' along the further sandy and muddy coastline. They form an ideal habitat for seaweed, sea anemones, mussels, snails, crabs and other crustaceans.

  • Rows of poles

    Especially in the southern Netherlands, the breakwaters on the beaches are often provided with rows of poles which provide an extra braking effect on the scouring tidal current.

  • Ecological wave breakers

    On the south pier in IJmuiden in the Netherlands, several dozen X-shaped blocks of cement have been placed as wave breakers to test its resistence to storms. This is an experiment to determine the strengh of these blocks. If the experiment succeeds, similar blocks will be placed on the north pier as well. Not only is 60% less cement needed, these objects also create new opportunities for marine animals. This Dutch invention is already being used in other countries.
    A new experiment started in 2008 with material that will help reduce CO2 discharges. They are by-products from oil production: one is extremely rich in carbon, called C-Fix; the other is sulfur cement. Instead of discharging 1 kilogram CO2 for every kilogram of cement that now occurs, C-Fix fixes 2.5 kilogram CO2 for every kilogram of the product. In addition, this product uses considerably less water. Research Institute Deltares and Rijkswaterstaat are responsible for the experiment.

  • Circulation currents by breakwaters

    Circulation currents can develop when the sea level drops during ebb and the water looks for ways to the open sea between two higher lying sandbanks. Deep channels perpendicular to the coast develop and where the water has a high current velocity. These dangerous currents can develop from natural tidal currents. It can also happen by a changing current pattern, caused for example by breakwaters. The current moving along a breakwater is often too powerful to swim through.

  • Rows of poles

    Especially in the southern Netherlands, the breakwaters on the beaches are often provided with rows of poles which provide an extra braking effect on the scouring tidal current.

  • Ecological wave breakers

    On the south pier in IJmuiden in the Netherlands, several dozen X-shaped blocks of cement have been placed as wave breakers to test its resistence to storms. This is an experiment to determine the strengh of these blocks. If the experiment succeeds, similar blocks will be placed on the north pier as well. Not only is 60% less cement needed, these objects also create new opportunities for marine animals. This Dutch invention is already being used in other countries.
    A new experiment started in 2008 with material that will help reduce CO2 discharges. They are by-products from oil production: one is extremely rich in carbon, called C-Fix; the other is sulfur cement. Instead of discharging 1 kilogram CO2 for every kilogram of cement that now occurs, C-Fix fixes 2.5 kilogram CO2 for every kilogram of the product. In addition, this product uses considerably less water. Research Institute Deltares and Rijkswaterstaat are responsible for the experiment.

  • Circulation currents by breakwaters

    Circulation currents can develop when the sea level drops during ebb and the water looks for ways to the open sea between two higher lying sandbanks. Deep channels perpendicular to the coast develop and where the water has a high current velocity. These dangerous currents can develop from natural tidal currents. It can also happen by a changing current pattern, caused for example by breakwaters. The current moving along a breakwater is often too powerful to swim through.