In the article the basic problems of water reservoirs, their impact on the surrounding ecosystem. The advantages and disadvantages of the construction hydraulic structures. In particular, the example of the Tsimlyanskoe Reservoir. Identified the main tasks were solved and types negative impacts on the environment that appeared after construction of reservoir . The conclusion about the need to assess the environmental risks associated with the operation of the existing hydraulic structures modern methods and means of measurement. The formulas for the parameters of hydro-physical and hydro-chemical processes, such as hydraulic flow characteristics and reservoir temperature regime. The necessity of building an actual mathematical model for a series of computational experiments. Using the data obtained will allow for prediction of eutrophication processes in the Tsimlyanskoe reservoir.

Keywords: reservoir, hydraulic structures, ecology, hydrological processes, thermal pollution, eutrophication, mathematical modeling, numerical simulation, anthropogenic impact, drinking water supply, Tsimlyanskoe Reservoir.