The current level of GIS technology and remote sensing allow systematically receive and interpret diverse information about the state and the individual characteristics of a water bodies variety and their catchment areas in a wide range of spatial angles. The use of space images significantly extends the capabilities of surveying, environmental and water works. The usage of the remotely sensed data and GIS – technology for the state monitoring of the water bodies is reviewed on the example of the Kyiv reservoir. The decryption of the features of satellite images for determining the distribution and nature of the vegetation overgrowing the reservoir is observed. The method of the detecting cells of Cyanobacteria algal bloom based on the values of the normalized vegetation index. Identify ways to use G²S technologies for hydro, environmental and water economy works. Satellite images obtained in different spectral ranges serve as the actual mapping framework that provides the extrapolation of data derived from observations of terrestrial and undersatellite. This approach is the use of integrated informative indicators opens up new opportunities to identify general trends in the changes occurring in ecosystems may form the basis of integrated monitoring of water bodies and their catchment areas to a new level and serve as the base of development of environmentally friendly methods of management. Keywords: water ecosystems, remote sensing, image interpretation, eutrophication.