This study assesses the radiological impact of groundwater on the general population living in the Manchanabele reservoir area, Bengaluru, India. The concentrations of 226Ra and dissolved 222Rn were measured using a HPGe gamma-ray spectrometer and RAD7 - an active radon detector, respectively. The 226Ra activity concentration ranged from 0.05 ± 0.001 to 0.88 ± 0.02 Bq/L (geometric mean: 0.17 ± 0.005 Bq/L) and is well below the WHO reference value of 1 Bq/L. Where as, the dissolved 222Rn activity concentration varied from 4.7 ± 1.9 to 625.8 ± 47.8 Bq/L (geometric mean: 38.3 ± 12.7 Bq/L), with 91 % of samples exceeded the WHO recommended limit of 11 Bq/L. The result of annual effective dose calculations from radon ingestion reveal that, from most of the samples it exceeded the WHO limit of 100 μSv/y, with higher doses to the stomach and small intestine. Additionally, correlations between 226Ra and 222Rn concentrations with bulk water parameters (pH, TDS, and conductivity) were explored.