Water scarcity is a significant issue in Iran, especially on its central plateau. Although climate change contributes to this problem, mismanagement and over-exploitation of available water resources worsened the situation. This study investigated water conservation opportunities in the Eskandari watershed, a crucial agricultural region in the Zayandeh-Rud River basin. We examined the trend of changes in all the factors affecting water resources in this watershed, including precipitation, discharge, leaf area index (LAI), inter-basin water transfer, and groundwaters from 2004 to 2019 at an annual scale. The classic Mann-Kendall (MK) and the non-parametric Trend-Free pre-whitening Mann-Kendall (TFPW-MK) statistical tests were employed to analyze the changing trends of these parameters over time. The results indicated that precipitation, discharge, and cultivated area have not shown any significant trend over 16 years. While in this period, the inter-basin water transfer tunnel entered into the basin with an upward trend, the water volume of all three aquifers experienced a drastic negative trend, suggesting an imbalance between the inflow and outflow of the watershed. Based on the groundwater depletion and the inter-basin water transfer inflow, an estimated 336.14 million cubic meters of water were consumed over the study period. This loss aligned with estimated water wastage in the form of wind drift and evaporation losses (WDEL) caused by the development of sprinkler irrigation systems in the study area. To address water scarcity and conserve water resources in the Eskandari watershed, it is essential to adopt sustainable irrigation practices that consider reducing the pressure on aquifers.