Improving saline soils is crucial for water and soil resource conservation, as salinity significantly hampers agricultural production in arid and semi-arid regions. Saline soils reduce crop yields, damage farming equipment, threaten food security, and make the soil unsuitable for agriculture. Many farmers in these regions cannot afford the costs of rehabilitating saline soils. Wastewater utilization in agriculture can partially address water demand and contribute to conserving conventional water resources. This study investigates the effect of saline soil leaching using drainage water in Buin Zahra, Qazvin Province. Saline soil samples were collected from depths of 0 to 30 cm using pre-designed cylindrical samplers to minimize disturbance and placed into six polyvinyl chloride (PVC) columns. To evaluate drainage effects on reducing soil salinity and electrical conductivity (EC), alternating columns were equipped with sand drainage layers or left without drainage. The HYDRUS-1D model was used to simulate water and solute movement during the leaching process. The leaching experiment was conducted on six soil columns with initial conditions of EC = 64 dS/m and pH = 8, using three water types: drainage water (EC = 57 dS/m, pH = 7.9), well water (EC = 2.54 dS/m, pH = 7.1), and a mix of both (EC = 32 dS/m, pH = 7.6). Results demonstrated the role of drainage and water quality in reducing soil salinity and electrical conductivity, offering insights into cost-effective strategies for reclaiming saline soils.