In the water management of the future, water security and water safety go hand-in-hand. Large parts of Europe are faced with flooding. But dry summers also produce drought conditions in natural, agricultural and urban areas. We have created the QARDAN Toolbox to analyse regional and local drought problems. And, drawing on our many years of experience with urban groundwater, we have also developed the WASSER Toolbox, with which we realise subsurface water storage solutions (ASR) with a regional scope. We use the Digital Twin approach to develop the physical set-up. In this way, we ensure a traceable, future-proof and reliable set-up of the regional water management.