Climate change is increasing the frequency and intensity of extreme hydrological events, posing significant risks to alpine communities. This thesis explores an innovative approach to flood risk assessment in mountainous regions by combining high-resolution surface modeling with advanced hydrodynamic simulations. Using photogrammetry and LiDAR technology, detailed digital surface models were generated and integrated into a high-performance flood model to improve forecasting accuracy. The study focuses on Bardonecchia, a town in western Piedmont at the end of Val di Susa, which experienced a severe flood event in August 2023. Triggered by intense, localized rainfall, this event led to a destructive debris flow, highlighting the need for fast, reliable, and easily deployable flood prediction methods.