Reservoir sedimentation is a significant issue that shortens reservoir life and has an impact on operations like irrigation, hydropower, and drinking water supply since it significantly diminishes the reservoir's initial capacity. Information on any changes in storage capacity is required to reduce the reservoir's risk. This study was conducted in the Amhara region of the Upper Blue Nile basin, Ethiopia. Bathymetric surveys and ArcGIS 10.3 were used in this study to estimate the sedimentation and life of the Angereb reservoirs. The quantity, distribution, and the sediment yield of the watershed were all calculated using the Revised Universal Soil Loss Equation (RUSLE) model. Based on the findings of the bathymetry survey (from 2007 to 2022), a total of 1.74Mm 3 sediment was deposited. Storage capacity decreased by around 56.83% throughout the fifteen years of operation (from 3.063 Mm 3 in 2007 to 1.32 Mm 3 in 2022) and an average annual reduction in storage capacity of 3.79%. Based on bathymetry survey results, the sediment yield (SY) and specific sediment yield (SSY) of the Angereb watershed were 128,639.51m 3 year -1 and 2031.34-ton km -2 year -1 , respectively. The gross storage capacity loss was about 70.20% (from 4.43 Mm 3 in 1997 to 1.32 Mm 3 in 2022) and an annual reduction in storage capacity of 2.81%. To estimate soil erosion from the catchment and prioritize micro-watersheds for soil and water conservation measures, the soil erosion model (RUSLE) was utilized. Based on the analysis, the mean annual erosion of the watershed as about 87-ton ha -1 year -1 , total soil loss from the watershed was about 606,283.86-ton year -1 , the sediment yield was 103,295-ton year -1 (15-ton ha -1 year -1 ), about 39.1% (2758.91 ha) of the watershed was categorized as slight class, and the remaining 60.9% (4206.85 ha) of land was classified as moderate to very high. In general, the findings will serve as a foundation for analyzing future sedimentation issues in the Angereb subbasin, and for developing sediment control and management methods for the reservoir. Keywords: Angereb reservoi r s, Reservoir sedimentation, Bathymetry, RUSLE and Blue Nile basin.