Rapid design of Nature-based Solutions with new tool

Nature-based Solutions (NbS) are solutions based on natural systems and phenomena. These natural solutions can be sustainable, cost-effective strategies for water management and climate change mitigation. By using natural processes and ecosystems, NbS increase climate resilience, improve water quality and counteract further biodiversity loss.

Hydrological models

The new tool from Deltares and Witteveen+Bos enables users to easily schematise and run calculations for Nature-based Solutions in wflow, the hydrological modelling framework developed by Deltares. Natural solutions such as land-use change or adaptations of waterways can be added to existing hydrological models, allowing users to quickly assess their effects at catchment scale.

HydroMT (Hydro Model Tools), an open-source Python package developed by Deltares, is used to build and analyse spatial geoscience models, in particular models focused on water systems. Wflow is widely used to assess flood risk, drought, climate change impacts and land-use change at regional to global scale.

Short calculation times

The collaboration between Witteveen+Bos and Deltares brings together extensive expertise in hydrological modelling and the practical implementation of Nature-based Solutions. The tool enables users to simulate different climate scenarios and visualise the effects of NbS through the open-source geographic information system QGIS. With relatively short computation times, the tool supports rapid schematisation and iterative design of natural solutions.

Co-creation

The fast simulations allow different NbS scenarios to be explored in real time. This facilitates a collaborative approach to solution design: stakeholders can thus easily contribute insights based on their local knowledge and expertise. Such a co-creation process ensures that implemented solutions are both more practicable and more effective because they are context-specific. Ultimately, well-informed decisions on solutions to climate-related challenges thus come within reach faster.

First release and demonstration

The first version of the wflow NbS design tool has been successfully tested and is now available via the QGIS plugin repository. Witteveen+Bos demonstrated the tool during the Deltares Software Days, at the wflow and HydroMT user day on 18 November 2025.

The tool can be installed and used by anyone as a QGIS plugin. The plugin includes basic wflow functionalities, such as:

• loading a wflow model;
• running a wflow model;
• adding gauge locations to a wflow model;
• visualising and comparing results from one or more models.

Nature-based Solutions supported by the tool

With the wflow NbS design tool, users can add the following Nature-based Solutions to an existing wflow model:

• land-use change (e.g. reforestation);
• check dams;
• terraces.

While the primary focus of the tool is on Nature-based Solutions, it can also incorporate reservoirs as an additional measure.

Impact

Deltares and Witteveen+Bos expect this tool to play an important role in improving climate adaptation strategies for river basins. By providing a user-friendly and scientifically robust platform, the creators aim to contribute to sustainable water management solutions and building resilient water systems that are more resilient to the challenges of climate change. The tool can significantly advance the design and application of NbS, making it a powerful tool for climate change adaptation.

Availability and accessibility

The wflow NbS design tool is being further developed by Witteveen+Bos and Deltares and is already available as an open-source QGIS plugin. This ensures broad accessibility for researchers, consultants and practitioners working on water management and climate adaptation. More background information on the tool can be found via the QGIS Python Plugins Repository.