Products of wet and dry deposition of aero-pollutants, reached by over-boundary or internal-boundary transport, are significant source of pollution, almost, whole territory of Serbia (Yugoslavia). Products of wet and dry deposition endangere surface storages in two ways: (1) directly, by deposition on surface storages; (2) indirectly, by deposition on surface of catchment areas, and further transporting through hydrographic system. In the period 1992-1996 investigations were carried out at some localities in Serbia (Yugoslavia). Their results show that recorded quantities significantly over pass MDK (maximal permitted quantity). Investigations included analysis of samples of precipitation (rain and snow), soil and sediment from hydrographic system.

The article gives review of concentration of copper in the water of the Bor lake basin. Content of copper in the mud on the bottom of lake and content of copper in the aerosol are analysed. The investigations have shown that the Bor lake is not polluted by copper.

Primary production of phytoplankton and diversity and biomass of zooplankton of the Sava reservoir (artificial lake), Serbia (Yugoslavia), was studied during the summer and autumn in 1996. The study results were compared with the research results by Perisic et al. (1984) obtained before the dredging of the lake bottom, when bottom sediments with macrophytes were removed. It was found that the water quality was improved in comparison with previous period.

Water quality observation is an important task which must performed at every water reservoir, especially at those whose water is used for water supply. In the purpose of easier and faster entering to storied data, for all potential users, and in the purpose of performing faster verification and handling data, two models are designed: 1) data base and 2) information system for dam observation and water quality management. These two models are parts of the Information System of Serbia for Water Resources Management, who is in development. Methodological bases of those two systems are presented in the paper.

Microbiological examination have been carried within the comprehensive hydrobiological investigation of Grosnica reservoir (Serbia, Yugoslavia) during 1997 and 1998. The aim of investigation was to establish the dynamics and fluctuation of specific physiological group. Grosnica reservoir with its microbial features belongs to quality class 1st-2nd according to Kohl. The comparison of bacteria community varies during the year depending of physicochemical features of a environment and the state of other facts in biocenosis. Dominant bacteria are facultative oligotrophic. The larger number of heterotrophic bacteria is in spring time only. Phosphomineralizers and proteolytic bacteria are present in the large number at the beginning of year, amylolytic bacteria are numerable during the summer and autumn. Number of nitrogen fixing bacteria and aerobic cellulolytic bacteria are changed depending on a season, too.

Important differences in the structure of fauna communities of their deepest parts of benthos were found in the investigation of several water reservoirs (Gruza, Grosnica, Barije, Bor, Vlasina and Medjuvrsje) on the territory of Serbia (Yugoslavia) lasting several years. The pronounced alterations of the structure are in the correlation to the pronounced degree of eutrofication was also established according to other indicators, above all according to the concentration of biogenic salts and the amount of organic substances. Characteristic group and taxa of the fauna of benthos which point to certain level of eutrophications were separated.

Monthly sampling in the Grosnica water reservoir near Kragujevac, Serbia (Yugoslavia), was carried out in the period October 1996 - September 1998. Comparison of the results with those obtained in 1950-1952 revealed changes in the qualitative and the quantitative composition of zooplankton. The presence of a considerably greater number of species was recorded, including some that were registered for the first time in this reservoir and which represent a very significant component in the dynamics of its zooplankton. A multi-fold increase of zooplankton production was also observed. The number of recorded species fluctuated from 26 in the winter to 59 in the summer. Average total abundance of zooplankton ranged from 100.7 ind./l (late spring to 2508.6 ind./l (summer). The results indicate an intensive process of eutrophication in the Grosnica water reservoir, the oldest artificial lake in the this part of Yugoslavia.

The present paper cites results of studying phytoplankton in the Grosnica Water Reservoir, Serbia (Yugoslavia). Seasonal investigations during 1997 and 1998 enabled us to establish composition and structure of the phytoplankton community, quality of the lake's water, and its trophic status. During the period of investigation, the phytoplankton community was characterized by forms of Cyanophyta, Pyrrophyta, Chrysophyta, Bacillariophyta, Euglenophyta and Chlorophyta. Qualitative analysis indicated that algae of the divisions Bacillariophyta and Chlorophyta are dominant in the phytoplankton, while saprobiological analysis using bioindicatory algal species showed that water of the Grosnica Water Reservoir during the given period was of the 1st and 2nd quality class.

Water reservoir "Gruza" is used forthe water supply of the town of Kragujevac and it's surroundings. The paper shows a comparative overview of physical, chemical and microbiological parameters during the period of 1987-1989, and 1997-1998. Variations of physical, chemical and microbiological parameters are given in the paper.

Regular monitoring of water quality of the Danube river in the backwater zone includes analysis of the sediment. It is well known that sediment is a sink place for the non degradable compounds and it reveales the long term water quality status in the reservoir. This paper presents the general results on the Iron Gate reservoir siltation. as well as some data regarding pollution level, based on investigations carried in the period of 2001-2002. The investigations included organic load of the sediment, heavy metals and organic pollutants content. The degree of pollution is evaluated on the basis of various criteria, also compared to results of previous case studies.