Van Aalsburg: pilot nature-friendly banks in Domburg Watergang

Biobased and circular work is no longer an optional ambition within water management. Water boards are looking for solutions that demonstrably contribute to the Water Framework Directive (WFD) and can be implemented in practice. Within that search and stemming from the completed SBIR project, Van Aalsburg is testing nature-friendly bank protection along the Domburg waterway, commissioned by the Scheldestromen Water Board.

Natural materials

“Here we are testing four innovative willow riparian protection structures to discover what works best as a solid bank in combination with biodiversity and water quality,” says Dick van Aalsburg. One of the techniques being used is a rowwood shoring system, constructed from two rows of posts filled with cots (bundled willow branches). Jute and wool replace the usual plastic geotextile in the process. “This creates a natural boundary between water and soil, and we are taking a step toward better water quality and more space for flora and fauna.” If successful, Waterschap Scheldestromen plans to use these pioneering nature-friendly structures more often to replace hard, natural solutions such as plastic and concrete.

Potential WFD measure.

Initial measurement results are promising. The natural variants tested appear to be considerably more sand-tight than many common geotextiles, contributing to stability and preventing leaching. The solution also scores well on environmental performance: it has an MKI value of 1.29 euros per m2. “That helps clients make an informed choice,” says Van Aalsburg. “Especially now that sustainability increasingly has to be measurable.” Rivierenland Water Board has already designated this type of shoring as a WFD measure. Other water boards such as Vallei and Veluwe and Aa and Maas also see this potential. “It is an optimal combination between a retaining structure and biodiversity. You give an enormous quality boost to both life under and above water,” Van Aalsburg knows.

Innovativeness and quality

The pilot builds on Van Aalsburg's previous innovations, such as zinc pieces with jute and wool, for which the company recently received the Cobouw Award in the Innovation category. “It makes me zealous that we can combine our old crafts with the latest techniques, creating natural solutions that improve water quality and are one hundred percent circular.”

Safety and sustainability

Working safely remains a prerequisite. Van Aalsburg is again certified on Safety Culture Ladder Step 3. “You can only innovate if you carry it out in a controlled way,” says Van Aalsburg. “For us, it's always about people enjoying their work and coming home safely in the evening.’

Finally, he points to a recent agreement with the energy cooperative Betuwe and Wind in Waardenburg, where Van Aalsburg is planting willows on land around windmills. “Nice to see that such a cooperative seeks sustainability not only in energy generation, but also in how the landscape is arranged.”