Offshore operations at Ecowende’s Hollandse Kust West wind farm have officially commenced with the start of nature-enhancing scour protection works. The wind farm is set to be the most ecological of its kind.
Van Oord’s subsea rock installation vessels Nordnes and Bravenes (pictured) have been deployed to install scour protection that has been designed to optimise marine biodiversity.
Scour protection is generally installed around the base of a monopile to prevent erosion caused by strong currents and waves. Stabilising the seabed in this way ensures the structural integrity of the turbine’s foundation. In the Hollandse Kust West project, scour protection is being taken to a new, nature-inclusive level of design.
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Innovative scour protection designs
In close collaboration with Ecowende, Van Oord has developed four innovative scour protection designs, each progressively more complex. These designs use stones of varying sizes, including a grading of 60–300 kg and with some stones up to 450 kg, to create larger openings and crevices between the rocks. These gaps provide shelter for fish and other marine species, while specially designed bays along the scour protection extend the length of habitat available.
The combination of variations in stone size and crevices, together with bay structures, enhances lee zones and creates more variety in open spaces; the rock–sand interface stimulates a richer and more diverse marine ecosystem, supporting species such as the threatened Atlantic cod.
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Monitoring biodiversity
Van Oord’s and Ecowende’s approach transforms scour protection from a protective measure into an active contributor to marine biodiversity. Once installed, the different designs will be carefully monitored to evaluate their ecological performance and long-term impact.
A milestone for Van Oord is the installation of the 60–300 kg grading, including rocks weighing up to 450 kg, with the Bravenes. This sets a new benchmark for large-scale, biodiversity-focused scour protection works in offshore wind.
Picture by Van Oord.
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