Unregulated sand mining has emerged as a significant anthropogenic stressor affecting riverine systems worldwide. This study investigates its impact on channel morphology, bank erosion, and riparian land use change in the Subarnarekha–Damodar river system of South-West Bengal. Using remote sensing, GIS analysis, and field observations, the study identifies spatial and temporal variations in river channel dynamics. The results indicate that excessive sand extraction has caused channel widening, bed degradation, and accelerated bank erosion. Furthermore, riparian zones have undergone significant land use transformation, particularly from agricultural land to settlements and barren land. The study emphasizes the urgent need for sustainable sand mining practices and integrated river basin management.