Reservoir siltation poses a significant challenge for dam managers and water reservoir operators, affecting various watersheds across Morocco. Dam managers often conduct bathymetric measurement campaigns to assess the extent of sediment deposition in reservoirs of numerous large dams in the country. However, because these operations incur considerable expenses, dam managers do not consistently conduct these campaigns, resulting in incomplete coverage across the 152 large dams in the Kingdom. The available bathymetric data for these dams, spanning a century, necessitates comprehensive analysis to provide updated siltation rates. In this study, we actively address this gap by systematically collecting bathymetric data on dam reservoirs and meticulously validating, correcting, and organizing the collected data for further analysis. Following this, we apply extrapolation techniques to estimate siltation rates for 2022. These estimates rely on trend curves illustrating the evolution of sediment volume over time, primarily revealing linear trends for most dams. For dams displaying nonlinear curves, we delve into historical factors such as human interventions like desilting operations or reservoir emptying and natural phenomena like drought years or exceptional floods to enhance our understanding of the sedimentation processes. The results of this quantitative analysis offer valuable insights and applications across various domains. They inform dam management strategies, facilitating maintenance planning, dredging operations, and optimizing storage capacity for long-term effectiveness. Additionally, understanding sedimentation patterns aids in identifying high-risk areas and implementing preventive measures for flood risk reduction. Furthermore, evaluating sediment deposition minimizes negative impacts on ecosystems and assesses potential environmental hazards, guiding land use planning in areas adjacent to reservoirs. Finally, these findings serve as a foundational resource for future research on sediment management, modeling, and enhancing dam management practices.