Leaf water potential (Ψl), net photosynthesis rate (PN), transpiration rate (E), stomatal conductance (gS), and water use efficiency (WUE) are greatly influenced by the nutrient composition of water which is used for irrigating trees. The above-mentioned physiological variables and foliage mineral concentrations were observed forEucalyptus camaldulensis,Acacia nilotica, andDalbergia sissooplants irrigated with municipal effluent (ME) at 1/2 PET (potential evapotranspiration; T1), 1 PET (T2), and 2 PET (T3) rates and the control plants irrigated with canal water at 1PET (T4). Increased mineral concentrations in order T1< T2< T3enhancedΨl,PN,E,andgS. Relatively greater increase inEthanPNreduced WUE. Available nutrient in ME enhanced physiological function in T2, whereas reduced quantity of water lowered it in T1than in T4plants. Differential minerals uptake increased concentrations of N and P inD. sissoo, Mn inE. camaldulensis,and the rest inA. nilotica.PNwas more sensitive to environment thanE. Enhanced mineral concentration through ME was beneficial but its differential uptake and accumulation influenced physiological functions and WUE.E. camaldulensisis better for high and continuous loading of effluent andA. niloticais best for high nutrient uptake.D. sissoois efficient water user.