Gadilam River is located in Cuddalore district, Tamilnadu nearer to Bay of Bengal. This river is used for agricultural purposes and by a 12-watt Micro hydro power plant. Using the Pollution Index and NSFWQI, this study sought to assess the water quality s tate of the Gadilam River at the Nellikuppam portion of Cuddalore that is impacted by a sugar plant, agriculture, and community activity (National Sanitation Foundation- Water Quality Index). The NSFWQI ranged from 84 to 87, while the pollution index varied from 0.54 to 0.76. As a re sult, the river’s water quality depends on these indexes. In summary, the Gadilam River’s water quality was not negat ively impacted by residents living along the riverbank or the micro-hydro plant.