Measures for the Wadden area

Milestones 2015-2023

In recent years, many impressive results have been achieved:

• A sand dike has been built in the Wadden Sea at the location of the Prins Hendrik dike on Texel so that this part of the Wadden Sea dike once again complies with the standards for flood risk management. A natural transition between land and water has been created in 200 hectares of the Wadden Sea with a new dune landscape alongside the old dike and a salt marsh landscape on the seaward side. This integrated operation resulted in the preservation of scarce agricultural land on Texel. The project was part of the Flood Protection Programme.
• The cross-project inventory study (POV) of the Wadden Sea dikes looked at a number of innovative dike concepts and dike materials with the aim of bringing the primary water defences into line with the statutory standard. The results were applied in dike upgrade operations during the inventory study. For example, in 2019, the Noorderzijlvest water authority constructed a double dike in the Eemshaven-Delfzijl dike upgrade project.
• The Coastal Genesis 2.0 programme generated a great deal of knowledge about the Wadden area and how the sandy system works. Studies and field measurements provided a clear picture of the workings of tidal inlets. The Wadden Academy and the Towards a Rich Wadden Sea programme published a review paper with the growth data for the different basins in the Wadden Sea. 
• In the Kerkhovenpolder-Germany dike section, the Hunze and Aa’s water authority completed the first section of the Broad Green Dike (over a distance of 750 metres) in 2022.
• The municipal authorities of the Wadden Islands and the safety regions of Fryslân and Noord-Holland Noord completed the pilot project, Integral Flood Risk Management Strategy for the Wadden Islands, in late 2022. No unacceptable flood risk management situations emerged at that time from the project. 
• In recent years, a range of sand nourishment operations have been conducted on specific sections of the North Sea coasts of Texel, Vlieland and Ameland.
• The Wadden Area Implementation Programme for 2021-2026 was completed in 2022. On the basis of this programme, the joint parties in the Wadden area are working on the implementation of the area agenda, Wadden Area 2050. In the context of the 2021-2026 Implementation Programme for the Wadden Area, the Wadden Area Delta Programme is establishing connections between flood risk management and transitions in the area of climate adaptation, and actively contributing the knowledge acquired in the Sea Level Rise Knowledge Programme. 

Plans for 2024-2026

The agenda for the coming years includes the following initiatives:

• The integrated implementation of the Lauwersmeer-Vierhuizergat dike upgrade began in March 2023. This operation will take advantage of three synergy opportunities for ecological water quality and nature: the creation of a salt marsh in front of the dike, a passage through the dike, including the establishment of an nature area of about 70 hectares behind the dike with tidal and fresh-salt gradients, and improvements to underwater nature. The Programmatic Approach for Large Waters (PAGW), the Flood Protection Programme (HWBP) and the Wadden Fund are contributing to this integrated operation. 
• The Fryslân water authority is upgrading 47 kilometres of Wadden Sea dike between the Koehool and the Lauwersmeer lake. For this operation, the national government is making funds available through the Programmatic Approach for Large Waters (PAGW) for the combined implementation of the flood risk management agenda and the improvement of the ecological quality of the Wadden Sea. Improvements will also be made to the Wadden Sea dike and the dune flood defence on Schiermonnikoog. The aim here is to establish a future-resilient primary flood defence that will strengthen the local area. The dike upgrade will be tackled section by section on the basis of a phased plan (2022-2025) and implementation phases starting in 2024. 
• Rijkswaterstaat will upgrade the dike near the village of Oost-Vlieland in 2024. 
• In 2022, the Eems-Dollard 2050 consortium built a ‘broad green dike’ for the Hunze and Aa’s water authority over a distance of 750 metres in the Kerkhovenpolder-Germany dike section. This is a ‘demonstration dike’ with a gentle slope on the sea side made from local clay. If, after three years of monitoring, this demonstration dike turns out to be a success, the whole dike section will be reinforced over the entire 12.5 kilometres with clay that has been extracted and ripened locally. 
• The follow-up to the Integrated Flood Risk Management strategy for the Wadden Islands will take place in 2023/2024. The strategy will then be specified for each island. 
• Work will take place in the years ahead on the second periodical evaluation of the preferred strategy. The current preferred strategy was adopted in 2014 (DP2015). The first periodical evaluation was in 2020 (DP2021) and the second evaluation is expected to be completed in 2026 (DP2027). The focus here is on the sustainability of the strategy, complemented by future scenarios and the associated adaptation pathways. 
   

Knowledge and research

The required research about the Wadden Area in the period 2022-2026 with respect to flood risk management in the long term can be found in the Knowledge Agenda of the Delta Programme. Important knowledge questions include: what effect will sea level rise have on the primary flood defences? What ecological processes in forelands and ‘biobuilders’ are possible to limit wave development and therefore improve the protection against flooding afforded by the primary flood defences? How can these processes be managed? How can measures for flood risk management improve the qualities (natural and otherwise) of the Wadden Sea? And vice-versa: how can nature measures improve flood risk management?