The recent influx of people into Dodoma City, Tanzania has greatly increased pressure on freshwater sources. To manage such stressed water resources, an assessment of evolutions of various groundwater masses using stable isotopes (SI) and hydrogeochemical facies was done. The major groundwater types were found to be NaHCO3 and NaCl. The groundwater in some areas was polluted with up to 223.7 ppm of nitrate-NO3-. The majority of water masses were found to be of meteoric origin and deep aquifers were mostly replenished by heavy rains which tend to become more depleted in SI. Further, delta D and delta O-18 from Hombolo Dam (HD) and Matumbulu Dam (MD) were highly enriched by evaporation, with average delta D and delta O-18 values, of 5.76, 39.69, 2.37, and 16.34 parts per thousand compared to average rains values of -5.52 and -32.99 parts per thousand, respectively. The contributions of highly enriched HD and MD waters to respective Shallow groundwater systems were 57.52 and 22.2%. Yet, it was found that 75.4% of groundwater in the Hombolo suburb originates from the Makutupora aquifer. Generally, this study offers a robust tool for adapting a local groundwater management strategy impacted by climate change, pollution, and overabstraction.