In this paper the results of preliminary investigations of microbiological quality of seawater and sediment are presented. Analyses are performed by membrane filtration. The samples were collected near the sawage outfalls in Bokakotorska bay. It is noticed much higher number of bacteria – indicators of fecal pollution in sediment surface that seawater overlaying the sediment. Concentrations of bacteria diminished in layers of sediment laying deeper that sediment surface. Influence of wastewater is the most evident on 1 and 3 positions.

In order to determine the stable isotope content of hydrogen (2H/1H) and oxygen (18O/16O) from surface water and the Zavoj Lake, a sampling campaign was carried out in November 2011. Vertical profiles of water samples were collected in the sections close to the dam to check whether there was any detectable influence from the inflowing Visočica River and wheter there was a vertical isotopic stratification of the lake water. Temperature gradient of up to 5.5 deg C between surface and about 60 m depth is observed. Dominant process of mixing the inflowing Visočica River and water leaking from diversion tunnel appear close to the dam.

Constant and highly productive agricultural productivity in the last decades has a tightly connected to irrigation. It is necessary to monitor the irrigation water quality in order to prevent or mitigate negative consequences on yield, soil and irrigation equipment. Besides the major waterways, the detailed canal network has great potential as a water resource. Peculiarities of this kind of water resources require monitoring of water suitability. During a three-year period of research, water was sampled on some localities in Backa and Banat (Serbia). The results of the research indicate that the water quality does not meet the demands proposed by the classifications. This proves the fact that during the irrigation period, it is necessary to monitor the irrigation water quality.