Acqua Alta: Adaptation Strategies and Flood Protection

This three-day conference in Hamburg features presentations by leading experts on efforts to adapt, methods of dealing with flooding and severe rainfall, and also water shortages across the borders of disciplines and of the regions. They include analysis of the concepts used by cities such as Copenhagen and Rotterdam to mitigate the consequences of flooding for their city and port. Climate change impact is responsible for severe rainfall events, and at the same time it may also cause periods of drought and water shortage in Northern Europe. Concepts for better drainage will therefore be very important in the future, as will resource management, not least to meet industrial needs.

Insights into dealing with climate consequences in other regions of the world are provided in presentations by speakers from Australia, Vietnam and Bangladesh. In Australia, the farmers in particular have to cope with severe flooding and with periods of extreme drought. A major policy requirement there is dual concepts – for flood protection on the one hand and water storage on the other. Problems of dike security in Vietnam will also be presented.

The programme also includes adaptation strategies for Germany and support by the Federation for corresponding measures in the regions and municipalities. For example, one of the programmes that receives funding is Klimzug-Nord, aimed at developing specific concepts for the Metropolitan Region of Hamburg and its population of some 4.2 million. The focal areas of the project are future urban and spatial development, including the requirement for more drainage and rainwater management. Here, and in many other projects presented at acqua alta, it is evident how important it is to achieve comprehensive interdisciplinary cooperation in the development of programmes – the positive effect is correspondingly high acceptance. A thematic forum at the acqua alta conference also addresses the need to get citizens involved in flood protection.

The planning of protection and adaptation measures is dependent on realistic forecasts of the regional impact of climate change. Presentations at the conference will show what difficulties the experts encounter in making such forecasts, and how a better picture of the situation can be obtained by comparing the various individual results now available. Water level forecasts are also very important in storm flooding situations, and also where flow rates are extremely low. They are a vital economic factor specifically for shipping. Experts will present the opportunities and show the obstacles to reliable forecasting. The same applies to difficulties in correct assessment of peak flood levels, which is very important for determination of the effect on engineering structures and river banks. Particular importance is attached to forecasting and joint flood management with rivers that flow across borders, and examples and models are presented in this area.

Civil engineering works remain essential in defence against flooding. An example of that is the consequences of the devastating floods in Saxony in 2002. They include the new construction and improvement of dikes in urban areas and the construction of five large flood retention basins in the Erzgebirge mountains; a presentation in this section summarises the major learnings from the process of simultaneous planning, approval and realisation of this major project. Other presentations describe innovative processes for dike improvement and stabilisation at coasts and along rivers, and flood protection planning in construction of the deep-water terminal Jade-Weser Port near Wilhelmshaven. Mobile flood protection systems are the subject of a special seminar conducted at acqua alta by BWK (Association of Engineers for Water Management, Waste Manage­ment and Land Improvement).

Waterside architectural concepts are likewise a subject of the conference, with presentations on urban planning for dikes and floodable areas in residential settlements. The aim is to show the interaction of constructional work for safety, and the creation of an appealing environment for the residents. Examples from Hamburg and the Netherlands will show how floating structures can make it attractive to live in floodplains.