An assessment of the water quality of Mahanadi and its distributary rivers and streams, Atharabanki river and Taldanda Canal adjoining Paradip was studied in three different seasons namely summer, premonsoon and winter. Four parameters namely pH, Dissolved Oxygen, Biochemical Oxygen Demand and Fecal Coliform were considered to compute Water Quality Index based on National Science Foundation studies. Our findings highlighted the deterioration of water quality in the rivers due to industrialisation and human activities.