Delta Decision on Flood Risk Management

In a low-lying country such as the Netherlands, flood protection is vitally important. As a result of climate change and the rising sea level extremely high water levels will occur more frequently. The essence of the Delta Decision on Flood Risk Management is that by no later than 2050, the probability of fatality due to flooding must not exceed 1 in 100,000 per annum (or 0.001 %) for every resident living behind the dykes. This is the so-called tolerable individual risk.

The Delta Decision on Flood Risk Management is underpinned by a risk-based approach. This enables more targeted investments in the flood protection of the Netherlands. Every resident living behind the dykes will have the same minimum level of flood protection. At locations where a flood would have a major impact (e.g., many casualties, great economic damage, and/or damage to vital infrastructure of national significance), the protection level will be raised.

Milestones in 2015-2020

New standards

Between 2015 and 2020, great progress has been made in the implementation of the Delta Decision on Flood Risk Management. For example, the protection targets have been translated into standards for the primary flood defences: the dykes, dunes, dams, and storm surge barriers that protect our country against flooding from the sea, the major rivers, and the major lakes. These standards have been set down in the Water Act, which came into force on 1 January 2017.

Assessment of primary flood defences and dyke improvement

The first National Round of Assessments of these primary flood defences commenced in 2017. A new set of statutory instruments is available to this end: a set of agreements and methods for the assessment of the primary flood defences. The progress is presented on the Flood Risk Management portal.

Furthermore, the Flood Protection Programme has been rolled out. In this Programme, the 21 district water boards of the Netherlands and the central government are collaborating on the largest dyke improvement operation since the Delta Works. The Flood Protection Programme is aimed at ensuring that the primary flood defences managed by the district water boards will meet the standards by 2050. This involves nearly 1,300 kilometres of dykes and nearly 500 sluices and pumping stations. Many dyke improvement projects are already under way.

Efficient spatial planning and disaster control

In addition to flood prevention, the Delta Programme also focuses on the containment of damage and casualties, should a flood occur nonetheless. Flood impact reduction can be achieved through efficient choices in spatial planning and disaster control. The Flood Impact Reduction Working Group submitted an advisory report on this issue in 2018. Impact containment through spatial planning is addressed in the Delta Plan on Spatial Adaptation .

Furthermore, the Steering Group on Water Crises and Flooding Management has improved disaster management during water crises. A Large-Scale Flooding Evacuation Module has been published, comprising an app and the website . The National Water and Flooding Information System  provides up-to-the-minute flooding information.

Plans for 2021-2026

Projects, activities, and milestones

The next few years will see the roll-out of projects and activities aimed at substantiating the Delta Decision on Flood Risk Management. These projects and activities are outlined in the Delta Plan on Flood Risk Management.

Several milestones will be achieved in this period:

  • By no later than 31 December 2023, the Minister of Infrastructure and Water Management will report to the Senate and the House of Representatives on the condition of the primary flood defences, on the basis of the first National Round of Assessments. The second National Round of Assessments will run from 2023 to 2034;
  • By no later than the end of 2024 the Minister will report on the efficiency and the effects of the new flood risk management policy;
  • In the years ahead, the Security Regions and their partners will continue to work on flooding and severe waterlogging: what is the potential impact and what measures can be taken? The findings will be accommodated in the national WAVE2020 programme that was launched in 2018. Guidelines will also be available regarding such topics as “saving people” and “recovery following flooding”;
  • In 2022, the Steering Group on Water Crises and Flooding Management will present a new joint vision on water crisis management, featuring a perspective for 2030. 

Knowledge and research

The knowledge issues relating to flood risk management are featured on the Delta Programme Knowledge Agenda . Key knowledge issues pertain to the rising sea level. The final results of the Sea Level Rise Knowledge Programme will be available by 2026. The studies involve the pace at which the sea level will be rising from the second half of this century onwards. The studies will also map out the tenability of the current flood risk management strategies, and the alternatives to keep the Netherlands safe and liveable in the more distant future.

The Ministry of Infrastructure and Water Management will continue to improve the tools for the assessment and design of primary flood defences on the basis of new insights, in collaboration with the authorities in charge of the flood defence systems.

The Steering Group on Water Crises and Flooding Management is expanding disaster management knowledge by promoting knowledge exchange between the organisations involved and by conducting pilot studies. The crisis partners share their expertise in the Netherlands Water Management Centre . Expertise and information is also exchanged at the international level.