Flexible Deltas

With Flexible Deltas, the DCC is investing in transdisciplinary knowledge development that is needed to adapt to sea level rise and increasing risks of storm surges, drought, heat and precipitation in the Southwest Delta.

With an eye on the long-term risks for future generations, the project is working on interventions that are needed now. Flexible Deltas tests the feasibility of and develops routes for flood-resistant landscapes, seeking a balance between flood risk management, water quality and ecology, social development, economic activities and the long-term well-being of citizens. 

Flexible Deltas is setting up several living labs that serve as testing grounds for a wide variety of flood-resistant landscapes. 

Read an interview with project leader Teun Terpstra below.

Flexible Deltas icon project: working together for a safe Delta

A climate-proof design for land-water transitions

Transdisciplinary knowledge development is needed to protect the Southwest Delta from flooding in the long term while achieving a sustainable balance between water safety, ecology, economy and the well-being of residents.

Within the DCC icon project Flexible Deltas, the concept of water-retaining landscapes is central to the multiple challenges in the dyke zone. Project leader Teun Terpstra, civil engineer and PhD in risk psychology, emphasises the necessity of this research. "We tend to assume too easily that the Netherlands, as a water country, can handle any challenge. But circumstances are changing dramatically: sea levels are rising and land subsidence is continuing. If we want future generations to be able to continue to live well and safely in this delta, we must act now. Passing this challenge on to future generations is unwise; the time they have left to find effective solutions is simply too limited."

The DCC icon project Flexible Deltas is a collaborative project between Utrecht University, Wageningen University & Research, Scalda, HZ University of Applied Sciences, University College Roosevelt and NIOZ in collaboration with Zeeland-based partners, including government bodies, nature and landscape organisations, businesses, umbrella organisations and local communities. ‘The concept of flood-defending landscapes encompasses more than just the dike or sea wall,’ Terpstra emphasises. "It also includes the area in front of the dike, the forelands and the area behind it, the polders. There are various challenges there, such as water safety, salinisation and freshwater availability, ecological functions and economic interests. This necessitates an integrated approach. Climate change, with its associated sea level rise, land subsidence and higher temperatures, is increasing the risk of flooding. This makes it urgent to create safer transitions between land and water. We are currently doing this by raising the dikes, but this traditional dike reinforcement means that the polders behind them are exposed to increasingly severe consequences as sea levels rise. With a flood-defence landscape, the consequences of flooding will be less severe. In other words, simply continuing to raise the dikes is no longer a structural solution to the increasing vulnerability of the delta. Moreover, due to silting in the dike zone, the soil can rise with the dikes, reducing the risk of salinisation. Flood-defence landscapes therefore also offer a future for agriculture and other land uses, such as recreation.

Research within living labs

As part of the Flexible Deltas icon project, practical research is being conducted at three strategic locations along the transitions from land to water in the Southwest Delta: the Westerschelde, Oosterschelde and the coastal zone. ‘On the various dyke sections, we are trying to clarify the long-term challenge and investigating the potential of flood-defence landscapes as a future-oriented solution.’

The research on the Western Scheldt has been ongoing for three years and forms the substantive basis on which Flexible Deltas builds. ‘We are now at the third dyke section and are setting new priorities through this iconic project. For example, we are expanding the research with modelling and involving additional disciplines, including legal issues and governance.’

The living lab on the Oosterschelde will start in the second half of 2025. The third living lab is expected to be launched just over a year later. "A living lab is explicitly a learning system in which knowledge exchange between science, policy, practice and the community is central. Scientific knowledge is important, but insufficient without the knowledge of area partners and managers. In other words, fundamental research alone is not enough. Social debate and shared involvement are also decisive for the effectiveness and support for the proposed solutions."

Long-term ambitions and outlook

The Flexible Deltas icon project has been set up as a five-year programme with the aim of laying a solid foundation for future-oriented delta strategies. By the end of the programme, Terpstra expects that area-specific strategies will be available that clearly identify the challenges that arise and the concrete building blocks that can be applied within the long-term vision for the Southwest Delta. ‘The ambition is that by 2050, we will not only have insight into what is needed to address long-term climate-related risks, but that we will also have tested and evaluated these solutions in practice,’ says Terpstra. "In this way, we will contribute to a climate-proof design for the Southwest Delta as a structural response to the consequences of climate change."