The aim of this study was to investigate the quality of surface water, more specifically, the river Glogovica in Slavonski Brod. It was necessary to take three samples of water from different locations following the flow of Glogovica which flows into the Sava, before the flood and after the flood. The methods used were the determination of nitrite (molecular absorption spectrometric method), determination of permanganate, ammonia, nitrate (ultraviolet spectrophotometric method), determination of pH, orthophosphate (method with ascorbic acid) and the determination of the CCP. Analysis showed increased nitrite, pH values, orthophosphate, ammonia, COD values and increased consumption of potassium permanganate. The value of nitrate was lower.The results were compared with the Croatian standards of wastewater, and the results showed that the results were within the permissible values. Nevertheless, the fact that the pollution occurred should not be ignored, and that it is not advisable for people use this water for any purpose, and that the flooding has led to greater pollution that is already present due to daily runoff portion of wastewater in Glogovica and river Sava.