Rijkswaterstaat, the executive arm of the Dutch Ministry of Infrastructure and the Environment, started a pilot with a block revetment consisting of new Hill Block dike stones. The new revetment will cover an area of 4000 m2 and is located near Stavenisse on the Zeeland island of Tholen.

Mushromm shaped stone
The Hill Block has a characteristic mushroom-like shape with large openings under the head. This allows the wave power are effectively damped.

The blocks are manufactured in two halves, which are independent from each other. This makes the stones easier to manufacture and for the shelves handier to put in place.

30 percent less wave run
The development of the Hill Block is an innovation in slope protection. Trials in the Delta flume at Deltares have shown that the waves against the dike decrease with 30 percent or more.

The water is by the shape of the new dike rock flows slowed and lower the slope of the dike.

Smaller embankments
According inventor Hans Hill, his stone not only lowers the cost of the dike increase, but also the social costs. Hill: "Raising a dike almost automatically means that the dike must by widened towards land with great social impacts such as expropriations, disruption of traffic.”

Environmental benefits
The Hill Block has also environmental benefits. For the production is 30 percent less concrete than necessary in existing dike rocks. Due to its special design created cavities which provide habitat for flora and fauna, both above and below water.

More information
Hillblock BV
Rotterdam, the Netherlands