Preferred Strategy for the Southwest Delta
The ambitions in the national Delta Programme for the Southwest Delta have been worked out in detail in a preferred strategy which is based on the Delta Decisions Flood Risk Management, Meuse and Rhine rivers, Fresh water and Spatial adaptation. The strategy was updated in 2020. In addition to flood risk management and freshwater supplies, the strategy also focuses on ecological resilience since a resilient ecology underpins a dynamic economy and a sustainable living environment in the Southwest Delta. Working on ecological resilience is essential in order to mitigate the adverse effects of human interventions such as the Delta Works. The preferred strategy has been worked up into a set of measures for the Southwest Delta.
Flood risk management
The preferred strategy sets out how we can keep the existing flood defences up to par until 2050 in accordance with the current insights and standards. In the context of the implementation of the Flood Protection Programme, preparations are being made for a range of dike upgrades. Every dike upgrade operation includes an assessment of the possibility of innovative dikes: dikes that open up opportunities in the short term for areas such as nature, leisure activities, cultural heritage or housing. The water authorities and Rijkswaterstaat completed the assessment of all dike sections in 2022. That resulted in a new and substantial upgrade agenda which they are now examining in greater detail.
In addition, separate strategies have been defined for:
- Grevelingen and the Volkerak-Zoommeer lake. This strategy focuses on establishing connections between flood risk management and freshwater supplies in conjunction with ecology and the economy.
- Eastern Scheldt. The strategy with an open, movable barrier for the Eastern Scheldt focuses on the future-resilient optimisation of the closure regime for the storm surge barrier, dike upgrades (and the associated innovations), and sandbank and riverbank replenishment. A sediment strategy has therefore been developed to maintain the sandbanks as a foraging habitat for birds.
- Veerse Meer lake. The strategy focuses on optimising water level management.
- Western Scheldt. This strategy focuses on dike upgrades (and the associated innovations) in combination with sound sediment management and the optimisation of the dredging and deposition strategy.
- Coast and Voordelta. The protection strategy, which is about making the coast and the Voordelta rise in line with the sea level, is linked to the spatial ambitions.
The Southwest Delta has two large freshwater basins that are supplied by the rivers: the Biesbosch/Hollandsch-Diep/Haringvliet and the Volkerak-Zoommeer lake. The freshwater strategy focuses on maintaining and, where possible, optimising these freshwater supplies for the surrounding areas. The Southwest Delta also includes areas surrounded by saline water where the influx of fresh water from the outside is not possible. In these areas, the strategy targets the improved retention of rainwater in the soil and the optimisation of water use by the business sector. 2021 was the final year of a process focusing on the planning period of the Delta Programme up to and including 2027 in which regional contributions were made to establish a package of measures. This included the Zeeland Freshwater Living Lab, a programme that experiments with measures that establish a better equilibrium between freshwater supplies and demand in areas of Zeeland where water influx is not possible.
Because of the connection with the freshwater supplies in the Southwest Netherlands, drinking water companies are exploring the potential role of the Area Consultation Platform for the Southwest Delta. National and regional governments are also collaborating intensively in the Area Consultation Platform to identify the consequences for freshwater availability and to develop appropriate solutions. There is administrative coordination for this purpose between the three participating provinces at the area level: Noord-Brabant, Zeeland and Zuid-Holland.
The Southwest Delta includes three working regions that work on spatial adaptation: Zeeland, Goeree-Overflakkee and the Southern Netherlands. Each region is developing its own approach. In Zeeland, the provincial parties have drawn up an action plan for the ‘Zeeland Climate Adaptation Strategy’ and they have signed a six-year implementation covenant. The strategy focuses on a robust freshwater situation and multi-layer flood risk management: a combination of flood prevention, spatial planning measures to mitigate consequences, and crisis management.
The provinces of Noord-Brabant and Limburg are working together on a Climate Adaptation Implementation Programme for the Southern Netherlands. Two of the thirteen working regions are located in West Brabant and they are part of the Southwest Delta. The provincial authority of Noord-Brabant mapped out the climate risks, provided municipal authorities with support in the area of risk dialogues, and developed the Climate Portal for sharing knowledge.