ABSTRACT
In the past the main objective of flood risk mitigation in the City of Hamburg has been concentrated on storm surges coming from the river Elbe. They have caused extreme damage and many losses of life in 1962 that this flood risk has been given priority. In 2002 extreme precipitation over the City of Hamburg caused great damage along the smaller urban rivers demonstrating the City’s vulnerability against flash floods of urban catchments.TheCity becameaware that the flood riskmanagement concept for these urban rivers needed to be revised andmodern technology and strategy of flood management to be included. The legal framework came from the GermanGovernmentwho has released a couple of newguidelines andwater acts for flood risk management, e.g. the five-point program, “Das Gesetz zurVerbesserung des vorsorgenden Hochwasserschutzes” and the “LAWA-guidelines” for a future oriented flood risk management. They require an integrative flood management strategy which includes the whole catchment of a river and gives priority to more space for the rivers. This new policy means expanding the relationship between the city, space and water, and setting a new, changed benchmark for building, planning and expansion of the city. However, considering the central theme of a “Growing city” which should have water implanted in the centre, this is not an easy undertaking – especially since the space in Hamburg is generally limited and expensive. It is necessary to create a basic understanding and awareness of the water (most notably the inland water), and also, to control runoff of the surface water. In the future, the water will be included as an important component in the existing and current city planning. The citizens should be informed about the possible individual and collective flood preparedness measures regarding their houses and be prepared for “living with floods”. This is even more important since the climate changes favour extremeweather situations, and heavy rain and flooding become increasingly likely.
