Freshwater lakes are important aquatic ecosystems that support domestic, agricultural, ecological, and recreational activities. However, increasing anthropogenic activities, urbanisation, and agricultural runoff can adversely affect water quality, emphasising the need for systematic monitoring and sustainable management. The present study aimed to assess and compare the physicochemical characteristics of Rangarayar Doddi Lake and Honganuru Lake in Ramanagara District, Karnataka, India, and evaluate their water quality with reference to World Health Organisation (WHO) drinking-water guidelines. Water samples collected from both lakes were analysed using standard methods for temperature, pH, total dissolved solids (TDS), electrical conductivity (EC), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), free carbon dioxide (CO₂), and phosphate. Rangarayar Doddi Lake recorded temperature of 21.15 ± 0.30°C, pH 8.35 ± 0.10, TDS 482.45 ± 0.80 mg/L, EC 112.03 ± 0.20 µS/cm, DO 6.52 ± 0.20 mg/L, BOD 1.61 ± 0.20 mg/L, COD 6.28 ± 0.60 mg/L, and phosphate 0.48 ± 0.06 mg/L. Honganuru Lake exhibited temperature of 20.75 ± 0.30°C, pH 8.30 ± 0.10, TDS 303.35 ± 0.80 mg/L, EC 103.19 ± 0.20 µS/cm, DO 7.49 ± 0.50 mg/L, BOD 2.55 ± 0.10 mg/L, COD 6.33 ± 0.40 mg/L, and phosphate 0.14 ± 0.01 mg/L. Free CO₂ was not detected in either lake. Overall, the observed parameters indicated relatively good water quality, with differences between the lakes reflecting variations in mineral and nutrient enrichment. Rangarayar Doddi Lake showed comparatively higher TDS, EC, and phosphate, whereas Honganuru Lake recorded higher DO. Continuous monitoring and effective watershed management are recommended for sustainable conservation of these freshwater ecosystems.
