Reservoirs have the potential for a variety of uses, including water supply for irrigation and domestic use, flood control and water power, but they are susceptible to filling with sediment due to erosion in the watersheds. Studies are needed to better understand erosion and sedimentation in order to figure out sedimentation rate and aspects or practices that increase these processes. Different approaches exist for estimating sediment delivery processes. Bathymetric survey was used in this study to estimate sediment deposition in Anjeb and Abrajit reservoirs and erosion. The analytical processes in this research work consist of the GIS software aspect and creating point data through TIN surface generation. Analysis of bathymetric results maps illustrating the present-day and pre impoundment topography of Anjeb and Abrajit reservoirs were found. The study result showed that there was significantly different sediment impoundment for both reservoirs as there was bathymetric change due to sedimentation. The result also showed that Abrajit and Anjeb reservoirs were highly silt up by sediment before reaching their life time .The RUSLE, analysis showed that the magnitude of annual soil loss of Abrajit and Anjeb watersheds where found the sediment delivery ratio the amount of sediment transported reach to reservoirs sediment estimated by RUSLE model for Abrajit and Anjeb was 1374.71 and 1518.23 t/km 2 /y which was very much less than found using bathymetry study which 9362.29 for Abrajit and 12889.61ton/km 2 /y for Anjeb respectively. The soil loss rate and the spatial patterns are generally realistic, relatively conforms well compared to what can be observed in the records as well as results from previous studies. The capacities and sediment volume for Anjeb was 1.0720 and 0.9534Mm 3 respectively for 2013 and 2021year. The estimated live storage capacities according to this study, calculated by subtracting the current to be approximately 0.119 M m 3 . The long-term average annual sediment accumulation rate was calculated by dividing the observed accumulated sediment volume values by the age of the reservoirs (8 years for Anjeb and 13 years for Abrajit calculated as the difference between the total capacities and sediment volume and the current capacities was 0.542Mm 3 , were 1.342 and 0.7986 Mm 3 in 2008 and 2021. This yielded long-term annual sedimentation rate of 12889.61ton/km 2 /y for Anjeb and 9362.29 ton/km 2 /y for Abrajit by the result of bathymetric surveying for the two reservoirs, respectively, implying an average annual storage loss from sedimentation of 11.12% for Anjeb reservoir and 4.5% for Abrajit reservoir. Key words: Reservoir, sedimentation, Bathymetric, RUSEL, ARC-GIS