Floating nature island made of pressed willow mat 

Amsterdam has another new piece of land. At 82 hectares, Strandeiland is IJburg's largest island. In the coming years, up to 6,200 new homes will rise here. Parallel to this new piece of Amsterdam, a 3-hectare Nature Island has been created with a reed landscape and a mussel bed. The foundation for this was laid with the Schaikmat, which was applied here on a large scale for the first time. A unique and extremely sustainable product from Dutch soil.

The Schaik mat is a development of Van Schaik, which has specialized in the manufacture of brushwood-related products for more than 60 years. "It is a sustainable and also local alternative to the coir mat," says director Teba Jongenotter. "The initiative for the Schaikmat came about eight years ago. Since then, we have continued to develop the willow mat and tested it extensively each time on small-scale projects." Natuureiland on IJburg is the first really large project where the Schaikmat has been used. Van Schaik supplied and installed no less than 12,000 m² of the pressed willow mat. 

Native product

The Schaikmat lends itself to various applications, such as solid bottom and bank protection, but can also be used as a floating island. "The latter to create ecological added value in watercourses or simply to beautify the appearance," Teba clarifies. "In the case of Natuureiland, a reed strip was already conceived during the design phase. Initially executed in coconut matting, but client Gemeente Amsterdam and contractor Combinatie IJburg were open to alternatives. So we offered our Schaikmat. A native and sustainable product, based on willow, which grows and is processed in the Netherlands. This is in contrast to coir that has to come from far away. The use of willow is also of interest to nature management organizations, because the purchase of the product makes it much easier to maintain the traditional willows."

Various types of planting

Van Schaik has developed a methodology for producing the mats by machine. "After pruning, the willow branches (toes) are laid out to dry at our production site in Ingen for a period of several months. Then the loose branches are compressed in the machine and braided into the Schaik mat of about 2 by 2 meters and varying in thickness from 10-20 cm," Teba explains. "To bind the branches together, we use untreated iron wire 2 mm thick. The idea behind this concept is that the entire mat including metal wire eventually decays, after which nature takes over the function. In the meantime, the plants have had a chance to take root. Various types of planting are suitable for the mat, ranging from helophytes to marsh plants. Here on Nature Island, reed was chosen."

Van Schaik connected the mats for Nature Island on dry land, anchored them and planted the reed plants. Only then was the area flooded. "We are now over a year on and all you see are the clean lines of green reeds. The mats are about 30 cm under water and are mostly fully grown with roots. So as far as we are concerned, we have already succeeded," Teba says proudly, adding that the Schaikmat is also extremely suitable for greening banks, as stated in the Water Framework Directive (WFD). "The durable mat can even withstand high wave action and strong water flow."