What materials were used? How do the gardens float? Which plants are growing? What is the idea behind the different gardens? These kinds of questions have led to a Program of Requirements that all these gardens meet. Here you can read more about the general principles and how each garden is different. Different partners were involved in each garden, and a number of gardens were created in co-creation.
Photo Waterkaravaan with canoeists: Coen Dijkstra
How do you make a floating garden if you don't want to use plastic or styrofoam? How do you ensure sufficient buoyancy even when the plants are getting heavier? Which local materials are suitable for this, and can you also use residual materials? Which parts should last a long time and which parts are allowed to compost more quickly under natural conditions?
The starting point here is that the shell and the connections last a very long time, but that some initial structures may perish: root packages from the plants themselves partly take over. This way, you can use more local and natural materials.
How do you create sufficient leeway against currents, waves and wind? How do you create structure, a three-dimensional matrix that provides support to plant roots and (micro) organisms? How to start a food chain
Native (local) plants are used that fit here, and that are also host plants for local insects and animals. Many different shore and aquatic plants have been planted, and it remains to be seen which plants are doing better or less well. Aquatic plant growers are closely involved in this project, what you might call an experiment. Especially when the plants thrive underwater, we are particularly satisfied. After all, they are having quite a tough time in the city, and it is quite a challenge.
Plants were adopted after the fireplace (when they clear the ditches in the autumn), plants were grown locally for this project, and plants were purchased from growers. An important requirement is that they can withstand Amsterdam's moderately brackish water, which is in open connection with the North Sea Canal. So there is a bit of salt in this, the percentage varies and depends on many factors.
In short: how do you create an environmentally responsible, floating, robust biotope that survives in the city?
In the autumn of 2025, the floating gardens will be moved to the Kleine Noorder IJplas. Here they lie quietly for a multi-year monitoring and research process.
The plan is to carry this out with the support and participation of Rijkswaterstaat, Waternet, Waardenburg Ecology, and TAUW (ecological research) and social firm Amsterdams Grachtenhout (maintenance). NOVAMBER ensures substantive coordination, design research and publication of the results.
