Preferred strategy for the IJsselmeer area

Flood risk management

The implementation of the preferred strategy consists of specific measures for the IJsselmeer area. 

Flood risk management

By 2050, the primary flood defences (the defences that protect us against water from the sea, and from the large rivers and lakes) must comply with the statutory standards that have been in force since 1 January 2017. The level of water in the IJsselmeer and Markermeer lakes in the winter is very important here.  

The guiding principle is that the average winter level in the IJsselmeer area will not rise between now and 2050. We are taking into account the option of a limited rise in line with the sea level after 2050; flexibility and adaptive rises in the water level in line with sea level rise are the main priorities.  
The water level in the IJsselmeer area is controlled with discharge sluices and pumps in the Afsluitdijk barrier dam. The strategy for flood risk management is based on the principle of ‘gravity discharge when possible, pumping when necessary’. Dike upgrades and the use of pumps on the Afsluitdijk are the main solutions in the IJsselmeer area to ensure that the standards for flood risk management continue to be met after 2026. 

Fresh water

The freshwater strategy focuses on two levels: the main water system and the regional water system. At the first level, the securing of the freshwater buffer plays a central role in combination with measures to tackle salinisation. At the second level, the focus is on retaining water in the regional system, reducing water use, smart distribution and tackling salinisation.  

In the IJsselmeer area, flexible level management is used to establish the largest possible freshwater buffer. Current knowledge and insights indicate that less water will flow to the IJsselmeer area through the IJssel river due to the uneven erosion of the riverbeds unless action is taken in the future. This is because the bed of the Waal river naturally erodes faster than the beds of the Lower Rhine and the IJssel. The Room for the River 2.0 Programme is looking at changes in the river system to address this problem, among others. If the discharge from Germany through the Rhine falls even further, bringing in water from the Amsterdam-Rhine Canal to the IJsselmeer area is an option. In the period between now and 2026, this issue will be explored through the Climate-Resilient Freshwater Supplies in the Main Water System strategy. 

The regional parties in the IJsselmeer area are committed to retaining water as much as possible and reducing the use of water by saving water and with smart water management.  

New developments requiring water have consequences for the freshwater buffer needed in the IJsselmeer area. For example, demand for drinking water could increase as a result of housing construction, the emergence of hydrogen plants for the energy transition, the construction of mega data centres and additional demand for water in the peatland areas to mitigate carbon emissions and land subsidence.  

A range of studies have shown that a reduction of water shortages in the future and the implementation of measures for salt management are needed. This can be done by raising the water influx, reducing water demand or by not allowing new water users in the area. In 2023, the water authorities therefore established a uniform way of working with new parties who want water. The Freshwater Delta Programme is investigating whether an approach of this kind can also be applied nationwide.

Spatial adaptation as an integral component

Spatial adaptation is a part of all plans and measures for the IJsselmeer area. An integrated assessment approach has been developed that links spatial development to the Water and Soil as Leading Factors policy paper, systemic measures and climate-robust planning. This integrated approach results in measures that serve multiple goals and obviates the need for a separate preferred strategy.