Water Quality Indices for Surface Water inHebbal Valley, Bengaluru, Karnataka, India.

The growing population and increased water demand has resulted in depletion of available fresh water resources and the same has caused imbalances in the ecosystem. This challenge of managing available water resources needs new approaches which should include social, economical and environmental factors. The quality of the available water must be evaluated to see how it fits the intended use. Water quality refers to the characteristics of a water supply that will influence its suitability for a specific use. One of the method to evaluate water quality is Water Quality Index (WQI).WQI are computed for surface water quality parameters in Hebbal valley for three seasons Viz., rainy, winter and summer. In the present investigation surface water samples from ten different locations have been collected and analysed for various physico-chemical parameters and same have been interpreted. WQI values in the study area vary between 34.07 to 52.62 with an average of 39.46for rainy season,31.08 to 55.54 for winter with an average of 38.36 and 36.71 to 58.61 for summer season with an average of 43.89 respectively. According to the WQI classification, most of the water samples analysed had good water quality except in few samples. In general higher percent of WQI values in poor and very poor water quality classes is mainly due to anthropogenic factors. The results obtained from the study indicates that water quality is generally good with few exceptions.