For a minimum flow study, sections of the Isar River were surveyed using a drone, GPS, total station, and Flowtracker. The drone captured overlapping individual images with RTK precision, which were then processed into georeferenced orthomosaics using the Structure from Motion (SfM) method. SfM was also used to generate terrain points, which were supplemented with data from ground-based surveys. Discharge measurements with the Flowtracker enabled the modeling of various flow scenarios.