In May 2022, Studio Calastri conducted a photogrammetric survey of Lago di Vogorno in Sementina, Ticino, Switzerland, at the request of the Verzasca Dam's management company. The survey aimed to obtain a comprehensive view of the basin's interior while it was empty for maintenance. Challenges such as navigating the U-shaped valley, overcoming obstacles like rocky walls and high-tension cables, and complying with drone flight regulations in mountainous terrain were addressed using innovative approaches. The team utilized the "smart oblique" system and RTK technology to achieve high accuracy and consistent lighting conditions during data acquisition.