Sixteen scientists from German universities in the field of hydraulic engineering and hydrology used the extreme event in 2013 as an opportunity to express their views on the improvement of flood protection in Germany. The goal is to promote the social dialogue on this highly topical issue.
Is German flood prevention failing?
Resolution dated 15.06.2013 by professors of the Chairs of Hydraulic Engineering and Engineering Hydrology at German universities
The floods of June 2013 have caused immense damage. Just like in 2002 and 2005, large parts of Germany have again been inundated. The question for the causes gets to the heart of our understanding of nature’s interaction with mankind.
We are of the opinion that:
Floods occur in the wake of extreme weather conditions. The 2013 floods were the result of extreme rainfall (200 mm precipitation depth within three days), falling onto already moisture-saturated surfaces (highest soil moisture for 50 years at the end of May 2013).
For centuries, people have settled on the banks of large rivers. If we want to continue using part of our river flood plains as settlement areas, we cannot go without technical flood control facilities.
Each flood is unique and reveals the boundaries drawn by nature, opposed to our efforts to control these events. Through technical structures, people can only influence the development of these extreme floods to a certain degree. Hence, they have to defend themselves against the implications of floods. In many German regions, dykes and flood retention systems, particularly the structures built or refurbished after the 2002 flood event, have served their protective function.
Complete flood protection does not make economic sense and is often technically unfeasible. Each increase in the degree of flood protection requires social consent. A comparison between the towns of Grimma and Eilenburg reveals that flood prevention requires the willingness to perceive one’s own risk and to cooperate. This requires personal responsibility from the citizens affected, thus adding to public flood precaution. Society has to make its choice: how much safety is safe enough? How high is the level of risk we want to take in future?
Technical flood protection does invariably have to go hand in hand with flood precaution (what happens if …?). A failure of protection systems cannot be totally excluded. There is always a residual risk. Its minimisation is also subject to the efficiency of the disaster prevention system in place. We have means to assess the consequences of failing technical systems. It is imperative to clarify in advance which events have to be prevented by all means (e.g. the loss of human lives or the collapse of critical infrastructure) and to focus preventive flood protection on high-risk zones. Flood risk management of this sort requires a unity of flood prevention, technical flood protection systems and disaster response.
Each avoided dike burst increases the flood risk of the downstream riparians. Therefore, large controllable flood polders and flood retention basins will have to supplement improved, stable dikes. The refurbishment and new construction of dikes in the regions currently affected thus requires interstate flood protection strategies.
The sole demand for “more room for rivers” does not do justice to the complexity of the problematic issue, distracts attention away from currently feasible solution approaches and is incapable of efficiently minimising the flood hazard for the decades to come. The deconstruction of dikes, just like the resettlement of residents of the areas subject to flooding, is a feasible option. However, this option cannot be successful unless it will meet with the political will and societal acceptance required. The numerous exemption clauses of the Federal Water Act allowing development areas in flood-prone areas give rise to doubts.
We in Germany are able to improve flood prevention. This requires expert knowledge that the German scientists are able and willing to contribute. Many new developments can already be implemented (such as new systems for dike monitoring and securing, new large-scale planning instruments for generating interstate flood prevention strategies on a river basin scale, overcoming the federal fragmentation of flood prevention in Germany, as well as new technical approaches to protecting buildings and constructing flood-proof buildings). However, this requires the awareness that flood protection is not a task recurring every once in a while, but a vital service of general interest in large parts of our country.
Improving flood prevention requires social dialogue in dealing with risks, open-minded thinking, reality awareness and the will and the power to change. We offer our assistance in implementing these objectives.
This resolution has been drafted by: