Rijkswaterstaat revises minimum distances for wind turbines near waterways based on new research

Rijkswaterstaat has updated its policy for the placement of wind turbines along Dutch waterways. The revised setback requirements are based on research carried out by TNO and MARIN and better reflect the characteristics of modern wind turbines, whose rotor diameters have increased significantly in recent years.

Under the previous policy, wind turbines could be installed at a minimum distance of 50 metres from the edge of a waterway. However, recent research showed that this requirement is not always sufficient for larger, modern turbines. In some cases, turbine blades can generate radar echoes that interfere with vessel and shore-based radar systems, potentially affecting navigational safety.

New minimum distance

Based on the findings, Rijkswaterstaat has introduced a new minimum setback distance of half the rotor diameter plus 35 metres from the edge of the waterway. According to the research, wind turbines installed at or beyond this distance do not create radar echoes over the waterway and are therefore acceptable from a vessel and shore radar perspective. The revised policy also allows for project-specific assessments. Developers may be able to demonstrate through additional studies that a shorter distance will not adversely affect radar performance. Such cases can then be evaluated individually by Rijkswaterstaat. However, this flexibility does not apply to locations with elevated navigational risks, including locks, bridges, weirs, waterway intersections and harbour entrances.

MARIN's contribution

MARIN carried out research for Rijkswaterstaat into the effects of wind turbines on safe and efficient shipping. The study examined the impact of wind turbines on radar performance, navigation and traffic flow on inland and coastal waterways. The findings contributed to the identification of safe setback distances and highlighted locations where additional caution is required. The updated policy provides greater clarity for permitting authorities and wind energy developers while continuing to safeguard the safety of maritime traffic.

Further information

For more information, please refer to the Rijkswaterstaat publications (in Dutch):
Rijkswaterstaat past afstandseisen voor windturbines langs vaarwegen aan
MARIN-onderzoek Effect windturbines op veilige en vlotte scheepvaart

For more information on the MARIN research contact Martijn Schipper.