The performance of reservoirs designed to store river runoff is seriously threatened by sedimentation processes. The accuracy of the empirical methods to predict reservoir sedimentation, distribution and flushing process is low and applicability is limited for certain type of reservoirs only and due to the limitation of the use of empirical methods, the development of the mathematical modelling is clear needed for an accurate prediction and simulation of future changes. The paper presents the conclusion of the authors based on a number of case studies where mathematical models are used for simulation of the flushing process.@en