This research evaluates the physical characteristics, and the isotopic signature of tap water andrnthe physicochemical characterization of groundwater and surface water to link water users ofrnAddis Ababa city to their respective water supply sources. As a result of the increase in cityrnwater demand caused by increasing populations in recent years, many groundwater waterrnsupply points (pocket areas) in the city have been drilled and injected into the previous mainrnwater supply pipe lines in various areas, resulting in a complicated and unclear distribution ofrnwater supply sources. Isotopic signatures (Î´D, Î´18O) and Electrical Conductivity (EC) of taprnwater samples collected from ten Addis Ababa sub-cities were used to map the spatialrndistribution of water supply sources. The isotopic signatures and EC measurements indicatedrnBole, Gulele, Addis Ketema, and Arada sub-cities heavily rely on the surface. Sub-cities such asrnAkaki, Nifas Silk Lafto, Lideta, Kirkos, and Yeka, on the other hand, rely heavily onrngroundwater. Kolfe Keraniyo, Yeka, and Kirkos sub-cities get a measurable amount of waterrnfrom mixed sources (surface and groundwater). Spatial distribution of water supply sourcesrnmapped using stable isotope ratios of hydrogen and oxygen (Î´2H and Î´18O) and EC wasrnoverlaid on Addis Ababa city population distribution. The overlay map showed up to 1.9Mrnpeople in the city depend on the surface water and nearly 1M people consume water abstractedrnfrom the groundwater sources. A noticeable number of the Addis Ababa city population (~800,rn000) get water from both surface and groundwater supply sources. The results implied, aboutrn50% of the Addis Ababa city population depends entirely on the surface water supply sourcesrnwhich are more sensitive to climate and demographic changes compared with the 25%rndepending on more climate-resilient groundwater supply sources. Given the current AddisrnAbaba city surface water supply production which only accounts the 40% of the total AddisrnAbaba city water supply, the dependence of a significant portion of the Addis Ababa cityrnpopulation may result in a continuous interruption of connectivity for part of the city which arernhighly dependent on the surface water supply sources. This study demonstrates applications ofrnPhysico-chemical and isotopic information to provide more sustainable and resilient urbanrnwater management perspectives which should be considered during the design and constructionrnof water supply infrastructure.