Stakeholder Workshop for the HydroExtremes Project

Too Much and Yet Not Enough Water

On April 14 and 15, 2026, a transdisciplinary stakeholder workshop took place at the Berlin-Brandenburg Academy of Sciences and Humanities as part of the HydroExtremes project. The goal was to strengthen the exchange between science, administration, and practitioners and to further develop joint approaches for dealing with hydrometeorological extreme events.

The focus was on the simultaneous challenge of water surplus (“too much”) and water deficit (“too little”). In the context of climate change, it became clear that both flooding and drought events are increasing in frequency and intensity and are already having significant consequences for the environment, infrastructure, and society. At the same time, both types of extreme events require integrated, cross-sectoral solutions. 

Project leaders Prof. Dr. Harald Kunstmann (KIT) and Prof. Dr. Peter Knippertz (KIT) began the workshop with an introduction to the goals and content of HydroExtremes. Expert representatives from both academia and the field then gave tandem presentations on current research and practical approaches to drought and flood management.

In the area of water scarcity, Dr. Veit Blauhut (LfULG Sachsen) used Saxony as an example to illustrate the impacts of drought events and emphasized the importance of historical analyses for adaptation strategies. Dr. Andreas Marx (UFZ) presented the German Drought Monitor as an established decision-making tool, but pointed out that a uniform definition of drought is still missing in Germany. In the area of flooding, new methodological approaches were presented. PD Dr. Uwe Ehret (KIT) highlighted the potential of AI-supported forecasts for small watersheds. Manuel Perschke (LfU Rheinland-Pfalz) explained a co-design approach in which models are developed jointly with partners in the field and integrated directly into operational systems, such as in the region Rhineland-Palatinate. 

This was followed by a presentation of key findings from a Helmholtz synthesis report as a basis for discussion along the process chain of hydrometeorological extreme events. Prof. Dr. Kunstmann emphasized the societal relevance of hydrometeorological extremes, while Prof. Dr. Knippertz highlighted the importance of meteorological fundamentals for forecasts. PD Dr. Heye Bogena (FZJ) presented new hydrological modeling approaches for water security, while PD Dr. Heidi Kreibich (GFZ) demonstrated in the area of impact and governance that additional damage parameters lead to more precise risk assessments.

In the subsequent stakeholder feedback session (aimed at reviewing the existing draft of the synthesis report), the desire for a stronger practical orientation became clear. The synthesis report should address applications more specifically, include a concise version for decision-makers, and better contextualize existing models. Additionally, there were calls for an AI guide for infrastructure approaches, practical examples, and a stronger focus on state-level needs (e.g., climate adaptation). Cost-benefit analyses and legally sound model applications were also identified as crucial for implementation.

The content was explored in greater depth during group work. The handling of uncertainties in decision-making processes was discussed particularly intensively. It was emphasized that probabilistic approaches should be used more extensively and that decisions should be based more frequently on probabilities and cost-benefit analyses. Examples from other sectors showed that uncertainties are already being systematically integrated there. For hydrology, this led to the conclusion that models need to be utilized more extensively as quantitative decision-making tools.

The second workshop day began with a summary of the findings as well as keynote speeches on the National Water Strategy (NWS). Steffi Lemke (Member of the German Bundestag and former Federal Minister for the Environment, Nature Conservation, Nuclear Safety, and Consumer Protection) emphasized the great social significance of water and the need to better prepare for extreme events. She described water as critical infrastructure and argued that the NWS must be consistently implemented. She also highlighted the importance of knowledge transfer, accessible communication, and positive “success stories” to strengthen public acceptance.

Regina Paas and Dr. Britta Ammermüller (both division heads at the BMUKN) presented the NWS from an administrative perspective and highlighted the workshop as an important platform for exchange and networking. They described implementation as a collaborative effort between the federal, state, and municipal levels. Key areas of action include data, monitoring, and floodplain restoration. Key instruments mentioned included the Low Water Information System (NIWIS, launch in 2026) as well as existing flood and heavy rainfall protection programs. A key challenge remains the limited availability of land for water management purposes. 

In a subsequent group exercise, participants developed visions for the future of collaboration between science, administration, and practitioners. Long-term cooperation structures, stable interfaces, a common language, and the early involvement of practitioners were identified as key success factors. The expansion of shared data infrastructures and standardized processes was also highlighted as crucial for better utilization of models.

Finally, the results were summarized and next steps were discussed. There was consensus that the greatest challenge lies in practical implementation. Particular importance was placed on the need to better integrate existing approaches, intensify cooperation, and make practical applications more visible. It was also pointed out that positive and solution-oriented narratives are essential for embedding the issue of water more firmly in society and politics. Overall, the workshop was considered an important step toward future collaboration and the translation of scientific findings into practical measures.