Lacustrine sedimentology, or sedimentology of lake environments, is a multifaceted and diverse depositional process that can significantly influence the development of construction sites adjacent to the lake. Construction design must account for geotechnical factors related to sediment features, including geometry, succession, and facies, as a preliminary measure to enhance safety, particularly in earthquake-prone regions like Lake Ranau, West Lampung. This study aims to establish a Particle Image Velocimetry (PIV) technique utilizing an Unmanned Aerial Vehicle (UAV) to assess the velocity and direction of surface water flow, as well as the geometry and gradient of Lake Ranau in West Lampung, in relation to sediment properties. Images captured from multiple UAV camera sites are concurrently and swiftly processed by highly redundant bundle adjustments, utilizing matching features from numerous overlapping offset images. High-resolution RTK GPS data and comprehensive geological observations subsequently refine the acquired model. The PIV technology measures surface velocity values ranging from 0.0128 to 0.0362 m/s at depths of 0.3 to 58.7 m. The measurement results indicate that the research area exhibits low surface velocity and sedimentation rate values. This is due to the lake environment’s characteristics, which exhibit a low sedimentation rate associated with very fine-grained sediment.