About the project

This project enables the long-term storage of carbon removed from the atmosphere through the cultivation and harvesting of fast-growing willow (Salix viminalis, Salix alba, Salix triandra). The harvested wood is bundled into “wiepen” (fascines) and woven into large mats, known as zinkstukken, or used as fascine bundles in waterworks such as riverbank protections, revetments, fish habitats, and submerged structures.

These natural engineering solutions are deployed underwater or in wet conditions, where anaerobic environments prevent the rapid decomposition of the willow. As a result, most of the biogenic carbon stored by the trees remains locked away for decades. For zinkstukken and fascine applications, a minimum lifetime of 50 years is assumed, ensuring durable carbon storage alongside essential water safety functions.

Zinkstukken are woven mats made of willow bundles tied with natural fibers such as sisal or jute. They are layered and fixed to geotextile (jute or polypropylene) and weighed down with stones before being placed on the riverbed or shoreline. In this way, they protect dikes, banks, and infrastructure from erosion while storing atmospheric carbon in a stable environment.

Fascine bundles and revetments consist of willow stakes and rods placed between rows of poles and tied with natural ropes. Around 80% of the biogenic carbon in these materials remains preserved after 50 years under anaerobic conditions, making them a significant contributor to long-term carbon sequestration.

By combining renewable willow resources with traditional water engineering techniques, the project turns a fast-regenerating natural material into a durable carbon sink that also strengthens infrastructure and protects landscapes.

About the remover

Van Aalsburg is a Dutch family-owned company with more than 60 years of experience in cultivating and processing willow. Today, it is one of the largest global producers of willow fascines and related water engineering products.

The company manages its own sustainably cultivated willow fields, which are harvested in short rotations of 3–4 years. After cutting, the willow stools resprout naturally, creating a continuous cycle of growth and carbon uptake. This closed-loop system ensures a steady supply of raw material while maintaining high levels of biodiversity and ecological value in the landscape.

In production, Van Aalsburg works with natural binding materials such as sisal and jute and ensures that harvested areas are replanted, securing long-term sustainability. Their expertise allows them to supply high-quality fascine bundles and mats to major clients including municipalities, Rijkswaterstaat (the Dutch water authority), and international contractors.

By transforming renewable willow biomass into durable waterworks that prevent erosion and protect coastlines, Van Aalsburg creates solutions that are both climate-positive and circular. Their work demonstrates how traditional craftsmanship and ecological resource management can deliver infrastructure that functions not only as flood protection but also as a long-term carbon reservoir.

See documentation

https://oncra.org/AALS-C-001

Wilg van de toekomst

Total

For sale

Holding