Bio Mapping of Water Quality in the Catchment Area of Arkavathi River - Karihobanahalli Lake, Karnataka, India

Surface and groundwater fluid content is controlled by natural features in the drainage network (geographical, topography, meteorological, hydrological, and ecological) and changes with ?uctuations in runoff amounts, weather situations, and water levels. As a result, huge natural fluctuations in water quality can be detected even when only a single watercourse is involved. Human impact has an important influence on the environment, such as the outflow of domestic, commercial, municipal, as well as other e?uents. As a result, it is vital to monitor the water quality at regular intervals. The Karihobanahalli Lake is one among four major lakes belongs to Arkavathi river basin. Water samples were analysed for critical water quality parameters i.e.; pH (Potentia Hydrogen), 2. BOD (Biochemical Oxygen Demand), 3. COD (Chemical Oxygen Demand), 4. DO (Dissolved Oxygen), and 5. TC (Total Coliform) and the Water quality index are developed. The water quality analysis reveals high BOD value of 24 mg/l, high COD value of 183 mg/l minimum DO value of 2.05 mg/l and Total Coliform concentration of 175000 MPN/ml of water indicating the pollution of lake due to discharge of untreated domestic sewage. for According to the Central Pollution Control Board (CPCB), water quality of Karihobanahalli lakes, indicates that the water is not suitable for drinking purposes, since the WQI class was E. Hence there is a need have interventions remediation measures for restoration of Karihobanahalli Lake. The interventions may be stoppage of direct entry of untreated sewage in to the lake, establishment of STP at strategic locations for treating the untreated sewage and stoppage of discharge of untreated trade effluent from industries.