Reservoirs are vital water sources that contribute significantly to local ecological and environmental balance, particularly in semi-arid regions. An evaluation of the drinking water quality index (WQI) has been conducted using ten water parameters like electrical conductivity (EC), chloride (Cl-), pH, total hardness (TH), total alkalinity (TA), phosphate (PO43-), dissolved oxygen (DO), nitrate (NO3-), total dissolved solids (TDS), and sulfate (SO42-). Weighed Arithmetic Index technique is utilized for examining drinking water quality status and USEPA model was utilized to determine the non-carcinogenic risk for ingestion of nitrate of Bhosga reservoir of Kalaburagi district which was measured at five predefined sites from October 2020 to September 2021. All the parameters of potable water were below the allowable limits based on given standards. The maximum WQI results were reported in monsoon season, with a mean WQI value of 48.14 from all the five selected sites, with the pre & post-monsoon seasons a mean WQI result of 46.08 and 43.68, respectively. Overall, the WQI value signifies that the water was of good quality, making it worthy for domestic use. The outcome of this study reveals that the pH and DO position have a substantial impact on reservoir WQI. Non-carcinogenic risk for nitrate ingestion reveled that, seasonal HQ average results for adults and children are ranging between 0.036 to 0.040 and 0.065 to 0.071, respectively and the HQ results for both adults and children were below 1, indicating neither adults nor children had any negative effect. Principal component analysis and cluster analysis revealed that primary causes of water quality degradation were agricultural runoff and anthropogenic activities. To ensure the security and the quality of water supply to people who live in the surrounding region, simple filter treating of reservoir water prior usage is needed.

Aquatic insects are the utmost generally employed macroinvertebrates in freshwater monitoring and assessment worldwide. However, aquatic insects have received far less attention for the objectives of health and water quality bioassessment, particularly in Kalaburagi, Karnataka. This study examined the abundance of aquatic insects in the Bhosga reservoir and their relationship to physicochemical factors. Water ecosystem health had been assessed using the BMWP, ASPT, and FBI scoring systems from October 2020 to September 2021. Samples were collected monthly by using the sweep net and dip net methods. There were 5964 aquatic insects recorded and divided into 23 families and 6 orders. Hemiptera (53%) was the most dominated aquatic insect family, followed by Coleoptera (16%), Diptera (15%), Odonata (8%), Ephemeroptera (6%), and Trichoptera (2%). Water quality falls under the class 2 category attributing "Good" water quality based on biotic indices. According to the PTI index, moderately sensitive to pollution group was abundant (74.11%) followed by sensitive to pollution (16.88%), and insensitive to pollution represented (9.00%) of the total abundance of aquatic insects. The compile of indices results indicated that the presence of moderately pollution sensitive families was higher than the insensitive to pollution families indicating that the aquatic habitat has not been significantly altered, nor is it very clean. The current study lays the groundwork for appropriate water management by using aquatic insects as bioindicators for assessing the water quality of the Bhosga reservoir.