The article analyzes the impact of displacement that taking place at the mouth of the Don River. This leads to a weakening self-cleaning process of water and increasing concentrations of contaminants. The basic sources of pollution of waters of the river Don and the main types of anthropogenic impact on the aquatic ecosystem. Cases of accidents in factories and transport, violation of wastewater treatment technology, as well as simply by negligence.The necessity of the control of non-periodic oscillations of water bodies located on them intakes, to prevent loss of quality drinking water supply. The main influence of these displacement prone city like Azov, Aksay, Bataisk and Rostov-on-Don. The conclusion about the necessity and the possibility of monitoring the state of the river Don, the organization without expensive continuous observation system with an extensive list of hydro-ecological indices.

Keywords: River Don, displacement, heavy metals, sediments, aquatic ecosystems, water intake structures, hydrological post

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.