All reservoirs are destined to be filled with sedment. As deposition depletes the storage space, the benefits that a reservoir is able to provide are reduced. The rate at which the total storage space is depleted is only a portion of the problem. Since different elevations are allocated for different purposes (flood control, power production, irrigation, navigation, etc.), it is important for those charged with the responsibility of planning and regulating reservoirs to know how the trapped sediment will be distributed over the planned economic life. In the past, several methods, both theoretically and empirically derived, have been developed to predict this distribution. Their general application as a predictive tool is extremely limited.In order to develop a methodology which has widespread applicability for predicting the distribution of sediment, the physical processes responsible for the patterns of deposition are used as the common denominator. These processes, to include reservoir operation, particle settling as related to size fraction, erosion in dewatered areas, consolidation, etc., affect sedimentation in relatively the same manner in all reservoirs. The processes are delineated and the complex interactions of the dominant processes are simulated using a computer model. Given the reservoir geometry (topographic survey), the water inflow versus outflow (reservoir operating rules), and expected sediment inflow, the model will provide a reasonable approximation for both the amount of sediment entrapped and the location of that sediment within the reservoir for the period of time chosen. Run-of-the-river, normally ponded, and semi-dry conditions can be modeled.