Vorsorge gegen Starkregenereignisse und Maßnahmen zur wassersensiblen Stadtentwicklung

Heavy rainfall events have occurred repeatedly in recent years and have led to considerable damage. The present report summarises the results of the UBA research project "Preparedness for heavy rainfall events and measures for water-sensitive urban development".

This project had three overarching goals: First, to summarise and analyse current state of heavy rain preparedness in Germany. Secondly, to examine the obstacles and synergies that exist to possibly integrate the risk of heavy rain into the three processing steps of the EU Flood Risk Management Directive (HWRM-RL) or into the national regulations of the Water Resources Act (WHG). Third, based on the identified needs for action, the project derived possible solutions for improving heavy rain risk management in Germany.

In the introduction to the report, the authors discuss the definition of "heavy rain" and the state of science on the occurrence of this phenomenon. Chapter 2 elaborates on the latter aspect and presents the current state of knowledge on geographic heavy rainfall hotspots and evidence on environmental impacts of selected events. Subsequently, the authors turn to aspects of heavy rain preparedness: Chapter 3 provides an overview of the different types of measures that are being implemented for heavy rain preparedness in Germany.

The following sections focus on selected types of measures: heavy rain hazard maps, multifunctional land use, warnings and communication measures. In each case, application examples, barriers and recommendations are presented. In chapter 4, the project team discusses the options for addressing heavy rain preparedness via the Flood Risk Management Directive (HWRM-RL), before presenting in the fifth chapter ten overarching recommendations for optimising heavy rain preparedness.