Comparative Water Quality of Bhosga and Khaji-Kotnoor Reservoirs, Kalaburagi, Karnataka

Abstract

Reservoirs in semi-arid regions like northern Karnataka characterize vital freshwater resources supporting drinking water supply, irrigation, fisheries, and local biodiversity. This study comparatively appraises the water quality of Bhosga Reservoir and Khaja Kotnoor Reservoir in Kalaburagi district based on key physico-chemical parameters. Sampling was carried out for a period of one year form April 2024 to March 2025. Parameters such as pH, Total dissolved solids (TDS), electrical conductivity (EC), dissolved oxygen (DO), total hardness (TH), phosphate, sulphate, and nitrate were analyzed. A Water Quality Index (WQI) was calculated to assess overall suitability. Results show that Bhosga Reservoir maintains relatively better water quality, with higher DO and lower nutrient and organic load, whereas Khaja Kotnoor Reservoir exhibits signs of stress due to elevated nutrients levels, particularly during Nitrate and sulphate. WQI classification indicated “Good to Poor” water quality for Bhosga and Khaja Kotnoor. The study recommends regular monitoring, eco-restoration measures, and reduction of anthropogenic inputs to maintain reservoir health.