In Ethiopia, lower consideration is given to irrigation water quality in comparison to irrigation water harvesting. However, the quality of the water has an effect on the production of crops and the health of the population. This research tried to address the characterization of different physicochemical properties of Selamco irrigation water in the dry (winter) and wet (summer) season. Samples were taken from the river mouth and dam outlet. Seasonal samples were collected from these two sampling sites, and composite samples were created for both seasons. Temperature, pH, turbidity, electrical conductivity (EC), and total dissolved solids (TDS) were analyzed in situ and water samples were transferred to the laboratory to be tested for heavy metal levels using inductively coupled plasma optical emission spectroscopy (ICP-OES). Temperature (20.60C-23.260C), pH (7.89–8.34), EC (118.9 s/cm-130.86 s/cm), TDS (58.8 mg/L-65.4 mg/L), and turbidity (6.57NTU-11.13NTU) were the results of the physical parameters during the dry and rainy seasons. Heavy metal values in mg/L analyzed were Cr (0.008–0.323), Mn (0.032–0.285), Ni (0.014–0.212), Zn (0.091–0.184), Cd (0.005–0.01), and Pb (0.014–0.249). Except for lead, the mean concentration of heavy metals in the dry season was higher than in the wet season, according to the findings of this study. Some heavy metals in the dry season exceeded the FAO guideline limit for irrigation, necessitating the attention of the appropriate authorities.