Abstract: Lakes are important feature of the Earth’s landscape which are not only the source of precious water, but provide valuable habitats to plants and animals, moderate hydrological cycles, influence microclimate, enhance the aesthetic beauty of the landscape and extend many recreational opportunities to mankind.  The release of domestic wastewater, agricultural runoff water & industrial effluents promote excessive growth of algae in water bodies, which results in their eutrophication. In the present study, Mysore’s  one of the major lake is considered for the study. Hebbal  lake is Situated at latitude 12°21ꞌ31ꞌꞌ N and departure 76°36ꞌ40ꞌꞌ E and is at an elevation of +751.220m. It is spread over an area of 17.44hectares.  The physical, chemical, biological characteristics of  Hebbal Lake were evaluated to estimate the quality of lake water. In this work, 12 grab samples were collected out of which 10 sampling stations from 5m shoreline and one station at centre and another one sample is collected where drainage water joins the lake.  The pH value ranges from 7.09 to 9.07. The minimum value of 7.09 was recorded in S12 and maximum of 9.07 in S1. Total dissolved solids observed in the lake ranges from 870 mg/L to 1970 mg/L. Minimum value of 870 mg/L was recorded in S6 and maximum of 1970 mg/L in S12. Turbidity ranges from 26.35 NTU to 84.6 NTU. The minimum value of 26.35 NTU was observed in S10 and maximum of 84.6 NTU in S12. The minimum value of 3.94 mg/L was recorded in S12,  in the month of March and May and maximum value of 9.815 mg/L in S8. COD values ranges from 24 mg/L to 174 mg/L. BOD values ranges from 140 mg/L to 455 mg/L. A minimum value of 140 mg/L was observed in S4 and maximum of 455 mg/L in S8.  . Iron ranges from 0.33 mg/L to 0.56 mg/L. A minimum of 0.33 mg/L was observed in S1 and maximum of 0.56 mg/L in S11. Certain parameters analysed like BOD, turbidity and hardness exceeds the maximum limits of the drinking water standards. The water quality index evaluated using CCME is 48, which =indicates the lake water as marginal.

Keywords: Water quality; Turbidity; Total dissolved solids; BOD and CCME model.

| DOI: 10.17148/IARJSET.2020.7914