In this study, the chemical characteristics, isotopic compositions (delta O-18, delta H-2), geothermal properties, and suitability for irrigation of groundwater resources were explored in Cubuk-Melikah (Ankara/Turkey). Water types present in the study area were mainly CaMgHCO3 and NaHCO3, with isotope compositions ranging from -10.6 to -9.06 for delta O-18 and from -75.62 to -61.93 for delta H-2. The mineral saturation index showed that samples were saturated with respect to aragonite, calcite, and dolomite, while anhydrite and gypsum were undersaturated. Reservoir temperatures, computed from silica geothermometers were 60-75 degrees C for Melikah thermal water. Based on the sodium adsorption ratio, residual sodium carbonate, soluble sodium percentage, permeability index, sodium percentage, boron and electrical conductivity values, waters examined in the study area were generally considered to be suitable for irrigation purposes.