The article provides materials for research and assessment of the effect of reservoir hydro-systems on the environment. A detailed analysis of the causes and parameters of the influence of hydroelectric small hydropower stations on the hydrobtological resources of rivers. The results of the study and the assessment of the pollution level of the bottom sediments of the head node of the Kashkhatau HPP are given, which confirmed a slight excess of the permissible concentration level in terms of the content of cadmium and oil products. The main factors influencing the low-pressure reservoirs on the natural environment and on the restoration of fish river resources of small rivers are determined. According to the results of engineering and environmental studies, a comparative characteristic of soil pollution by oil products in relation to the permissible level was established, analyzing the results obtained, it was concluded that the content of oil products in the collected soil samples is within the established standards. A comprehensive assessment of pollution of water resources and soils of coastal water protection zones is given.

Keywords: reservoir waterworks, small hydropower plant, aquatic and biological resources, solid runoff, river pollution, flood waters, background concentrations, heavy metals, hydraulic structures

The article presents the analysis and safety assessment of hydraulic structures in the upper-Balkar small hydroelectric power plant. This is done for a project for the suspension and preservation of hydraulic structures Verhnebakansky of a small hydropower plant on the river Cherek in Kabardino Balkar-Balkar Republic. A detailed analysis of causes and factors of external impact of natural and man-made disasters on structures. Determined that most dangerous mountain of the construction site are the physical and geological processes. Established that the level of safety of hydraulic structures Verhnebakansky Small hydropower plant at the time of the survey can be assessed as normal. The values of all controlled parameters do not exceed the established safety criteria. Developed and implemented design solutions for the period of the suspension of construction and the stage of preservation provide strength, stability and safety of structures. Object safe for people and the environment.

Keywords: hydraulic structure, small hydro power plant, free-flow diversion tunnel, a sump, diversion tray, physico-geological processes, risk assessment, hazard ratio, possible crash damage, quantification of risk, negligible risk