Abstract:
This article analyzes and evaluates the current changes in the quality of river waters in the basins of Topolnitsa and Luda Yana. The rivers are experiencing significant anthropogenic impact of various origins and nature. To assess the impact and condition of water quality index used in many countries around the world has been used. Respective Bulgarian normative documents give the opportunity to obtain representative results and to be compared with the reference values of the indicators in the index. The critical condition of the river sections of the rivers Topolnitsa, Mativir and Luda Yana near large settlements has been determinate. Local pollution is usually caused by frequent discharges of wastewater from livestock farms. In the lower reaches of the main rivers there is a gradual change to improvement of water quality in terms of physical and chemical parameters used.