Monitoring and surveys

Dead wood reefs

Dead wood, such as fallen tress, naturally belongs in Dutch waters. Various types of insects and fish live on and around these type of structures. However, water authorities are used to removing fallen trees and branches from the water. That is why we work with them to see where we can return this wood to our water systems to improve ecological water quality.

Trees, branches and roots provide structures underwater. These structures create crucial habitat for specific species, such as algae, diatoms, fish and macrofauna.

Water Framework Directive

Waardenburg Ecology conducts research into dead wood in rivers. Together with Rijkswaterstaat, we undertook a trial to anchor dead trees underwater in tributaries of the Rhine. The positive results of this research have ensured that returning underwater trees to waterways is now being implemented as a Water Framework Directive (WFD) measure in many places. In addition to the research, we have also drawn up guidelines for the placement of dead wood in rivers.


There are all kinds of variations on dead wood reefs being developed, such as the installation of branches in places where space is limited, such as in harbours. Wood can also be used intelligently to adjust processes such as sedimentation or erosion. However, not every method works equally well or for the disired period. Waardenburg Ecology has the knowledge to identify and develop the most effective method for each specific situation.