Abstract
<jats:p>The article examines the critically important task of ensuring the unconditional safety of hydroelectric facilities, using the Krasnoyarsk Hydroelectric Power Plant as a case study, which possesses a massive hazard potential. The relevance of the research is driven by the necessity of conducting a preventive risk analysis to avert catastrophic consequences associated with large-scale flooding. A systematization of threats has been carried out, dividing them into external (seismic impacts, extreme floods) and internal (failures of electrical and hydro-mechanical equipment, degradation of structures). Based on this classification, two detailed emergency scenarios have been developed: the most probable (equipment failure during the passage of a flood with a recurrence interval of 0.1%) and the worst-case (a cascade failure of all generating units, analogous to the accident at the Sayano-Shushenskaya HPP, during a flood with a recurrence interval of 0.01%). The methodological foundation of the work is hydrodynamic modeling of flood zones using the HEC-RAS software complex. A step-by-step methodology is described in detail: preparation of a digital elevation model and river channel geometry in QGIS, configuration of structure parameters and boundary conditions, model verification, and execution of steady and unsteady flow calculations. The modeling results are presented as quantitative estimates of flood parameters (maximum depths, flow velocities, wave travel time) for a number of settlements in the upstream and downstream pools. It has been established that the realization of the worst-case scenario leads to the inundation of an area of 575 km² in the upstream pool and the propagation of a flood zone extending 364 km in the downstream pool with increased hydraulic parameters.The obtained results create a scientifically grounded foundation for assessing potential damage and developing specific preventive measures to enhance the safety of the hydraulic structures.</jats:p>