<p>Groundwater recharge estimation is critical for managing water resources in semi-arid regions, where water scarcity and overexploitation are prevalent. This study employs an integrated approach combining the chloride mass balance (CMB) method—applied in both the saturated and unsaturated zones—and the water table fluctuation (WTF) method to quantify recharge in the Upper Cheliff Alluvial Aquifer, Algeria. A comprehensive field campaign conducted in April 2021 collected 5 rainfall samples, 49 groundwater samples, 48 irrigation water samples, and 49 soil samples from unsaturated zone profiles. The CMB method revealed recharge rates ranging from 6 to 229 mm/year, while the WTF method estimated higher rates of 58 to 315 mm/year, reflecting the influence of diverse recharge sources such as rainfall, irrigation return, and wadi infiltration. These results highlight pronounced spatial and temporal variability in recharge driven by land use patterns, the intensity and type of irrigation practices, and anthropogenic inputs associated with densely populated areas, particularly the subsurface infiltration of domestic effluents from septic systems. The study highlights the importance of integrating multiple methods to account for the intrinsic characteristics of each approach, with the WTF method providing a more comprehensive estimate of actual recharge and the CMB method offering insights into diffuse and irrigation-driven recharge. This integrated approach enhances the accuracy of recharge estimation, providing valuable insights for sustainable groundwater management in semi-arid regions. </p>