The security problems on the objects of the Aley River water complex are of the particular importance as they relate not only to the possibility of flooding, but also of the interruptions in water and energy sources for the settlements in case of accidents. In consideration of the foregoing premises the aim of this work was to evaluate the consequences of the hydrodynamic accident on Sklyuiha Reservoir according to the simulation dam break wave parameters. The article presents the features of Sklyuiha Reservoir as the object of water use by Rubtsovsk city (Altai Krai). The engineering situation in hydrodynamic accidents on Sklyuiha Reservoir has been evaluated. Also the main consequences of possible flooding on the populated areas below the reservoir have been revealed. The time of break wave approach, wave height and duration of the break wave coming have been calculated. Minimizing of the accident consequences on the hydrotechnical constructions is based mostly on the ability of operational adequate decision- making under the conditions of rapid environment changes. Reasonable decision- making at the initial stages of development and the elimination of emergency is the best way to make effective use of available forces and resources for the early elimination of accidents and minimizing its consequences. Hydrological accidents forecasting according to the simulation parameters is necessary for operational information, management and coordination of managers and specialists in services and departments.