The economic life of the dams is determined by the sediment load from their own basin. The most important factor terminating the life of the dam is filling of dead volume of the reservoir by solid materials (sediment, sedimentation, deposit material) carried by the river. In this study, sediment deposition in Cakmak Dam built on Abdal stream of Yesilirmak Basin was investigated. Using the bathymetric maps of the dam reservoir belonging to 1988 and 2014 years, the bottom profiles and cross-sections at regular intervals were drawn by using NetCad 7.6 program. The elevation differences occurred by sediment loads were determined from drawing bottom profiles. In addition, using the elevation-area-volume method, the volumetric and areal losses of water in reservoir dead, active and total volume for 26 years were calculated. As a result, the volume of the dam was filled with the sediment. From the results, it has been observed that up to 10 meters of elevation occurs on the bottom of the reservoir due to sediment deposition. Approximately 30% of the dead volume determining the useful life of the dam was filled with sediment.