The Hydraulic Engineering Departments carry out project-related studies for Germany's 7,350 km of inland waterways and 23,000 km² of coastal waterways. Field investigations are prerequisite to obtain high-quality data about natural processes. The results consist of impact forecasts and basic decision-making documents for planning both maintenance and upgrading work (e.g. river engineering concepts, hydraulically optimized waterways structures, fairway dimensions) and also for efficient operation of the natural and manmade waterways. Research and development work expands the necessary principles and state-of-the-art in hydraulic engineering. This demands a comprehensive understanding of the system, taking account of the interactions between the dynamic water body and the maintenance structures, the river bed, the atmosphere as well as the shipping and the biotic conditions.