A COMPREHENSIVE WATER QUALITY REVIEW OF RIVER YAMUNA WITH SPECIAL REFERENCE TO WATER QUALITY INDEX IN THE HIMALAYAN REGION OF INDIA

India with 4% of fresh water resources is facing a dual challenge scarcity and pollution. Several rivers in originate from Himalayan systems forms the basis Indias Economy. River contamination diminishing quality reducing populations accessibility to clean safe drinking Water. As one significant perennial tributaries The Ganga Water systems, Yamuna passes through heartlands thegreat North Plains sustaining cities, feeding millions. Since major urban settlement it heavily polluted untreated industrial waste, sewage, domestic waste making its way into river. study presents comprehensive reviewof assessmentsof theriver special reference Quality Index based on severalhydrological parameters. Based levels whole stretch source (at Uttarakhand) till confluence Allahabad) has been divided 5 segments. While all lower stretches depict high very pollution levels, upper segment river Himalayas show good quality. parameters that BOD, DO COD are not range permissible limits Delhi but falls under segment. Other than these parameters, ammonia, TKN other organic inorganic matters fall desired standards region Yamuna.