When will the Netherlands disappear?

IX. The big structures

In the last century the Dutch built some huge hydraulic engineering masterpieces such as the “Afsluitdijk” near Den Oever and the Deltawerke, a group of hydraulic engineering structures in the province of Zealand and in Rotterdam. The aim was to shorten the coast of the Netherlands and thus guarantee the security of the country. All the structures would run into problems if the sea level rose. As part of the Delta program, it is investigated what possibilities exist to adapt the structures or to plan alternatives to today's flood protection measures. The question arises whether it is possible to combine flood protection measures with measures in other areas. For example, the “Brouwersdam” in Zealand is thinking about building a hydroelectric power station.

Another example is the “Afsluitdijk” ‘. Raising the dyke is not a technical problem there. One point of discussion is the question of whether the level of the IJsselmeer, which is closed off from the influence of the sea, can be allowed to rise with the rising sea level. Today the water that flows through the IJssel into the IJsselmeer is let out into the sea by opening gates. When the sea level rises, however, this is no longer possible at some point. So you have to choose either to enlarge the IJsselmeer basin by raising or relocating the dike, or to pump the water out of the IJsselmeer. The Netherlands opted for the latter. The cultural and historical picturesque towns and villages along the IJsselmeer are too valuable to disappear under or behind huge dikes. In the IJsselmeer area, in addition to flood protection, the question of whether the freshwater supply of the IJsselmeer will be sufficient in the future also plays a role. This question has led to the current water management of the IJsselmeer being well reconsidered. It became clear that a more flexible setting of the water level of the IJsselmeer would mean great opportunities for the internationally unique nature that exists here. In today's situation, a distinction is made between an artificially stable winter and summer level. By dealing with the water level more flexibly, i.e. taking into account the actual weather conditions and the demand for fresh water, reed areas could be created at the edges of the water, which can serve as breeding grounds for fish and water birds. At the same time, the ability to control the fresh water supply is improved.

The uncertainty of the future

The previous history of flood protection teaches that when taking measures, one must always reckon with a changing situation. How should one plan ahead up to the year 2100? 150 years ago, who would have expected so many people to live in the flood-threatened part of the Netherlands today? Only 50 years ago the word climate change was virtually unknown. In order to still be able to plan for the future, the Meteorological Institute of the Netherlands KNMI has worked out four scenarios together with the Dutch Institute for Spatial Planning that describe how the Netherlands could develop. The scenarios describe four possible future situations by combining two climate scenarios with two socio-economic scenarios. The four visions of the future vary, on the one hand, through rapid or slow climate change, and, on the other hand, through the assumption of socio-economic growth or socio-economic decline. All strategies of the Delta program are assessed on the basis of these scenarios. Ultimately, all actions taken under the Delta program must be functional and realistic in all four scenarios. So one hopes to prepare flexibly for the future and not burden the next generations with the wrong decisions of today.

Another method to prepare for the future is "adaptief delta management" ‘. The main goal of “adaptive delta management” is to ensure that it remains possible to carry out future measures as soon as they are necessary. Measures taken today must not make it difficult or even impossible to implement future measures. Flexibility, the connection of short-term with long-term measures, working with several possible strategies and the connection of different budget plans are core topics of "Adaptive Delta Management".

It is of course unrealistic to assume that we know today which measures will be carried out in 50 or even 100 years. The level of knowledge and social and physical circumstances will change. However, since many measures require a long preparation time, you have to start planning future measures today - even if they may never be carried out. And sometimes you have to take measures today to enable measures 50 years from now.

Author: Dagmar Keim
Created: May 2014