Abstract: A systematic study was conducted to evaluate the water quality status of the River Bohimora in Sonitpur District. To assess and monitor its habitability and water-usability, 15 water samples and many macro-invertebrates were collected from three sampling stations and analysed for physicochemical parameters (temperature, transparency, turbidity, TDS, pH, and DO) and diversity indices (Shannon index, Simpson index). Each parameter was compared to other studies on river water in various studies. The analytical data of various physicochemical parameters show that some parameters, such as transparency, are degrading and unfavourable to the biosphere adjacent the river's mouth. These values indicate that water samples from some sampling stations are unfit for drinking due to high TDS levels. These physiochemical findings also support the decreasing biotic indices near the river mouth. Observations were made about the possible causes of these deteriorating parameters.

Keywords: Biodiversity Index, Water quality, Physico-chemical parameters, River water

| DOI: 10.17148/IARJSET.2021.81126