Groundwater serves as a primary source of irrigation water globally. However, its quality is threatened by rapid urbanization, improper organization of agricultural work, and the expansion of industrial activities. Groundwater is of paramount significance in Armenia, especially within the Armavir region, which encompasses the area under investigation. For the first time, an initiative was taken in the Armavir region to assess and map groundwater irrigation properties using advanced methods, taking into account both the climatic conditions of the area and the influence of anthropogenic factors. The studies were carried out between 2022 and 2023 years. Sampling was carried out from 72 wells, 41 of which belonged to unconfined aquifers and 31 to confined aquifers. Chemical parameters (pH, EC, and Cl−), different indices (SAR, Na%, MH, RSC, PI), and graphical representations were used to evaluate the quality of groundwater. However, better results can be obtained if not individual groundwater parameters are assessed, but a comprehensive approach is applied. In this regard, a more effective solution is the Irrigation Water Quality Index (IWQI), which combines many indicators and expresses groundwater quality in a single value. As a result of our research, it was found that lower IWQI values were obtained in unconfined aquifers, and long-term use of these waters can lead to salinization and degradation of agricultural lands. The IWQI complex index and GIS-based methodology used to assess the quality of irrigation water in the Armavir region can be applicable and beneficial to other agricultural areas worldwide. It can help develop a continuous quality monitoring program to assess the irrigation properties of groundwater, which can be a tool for the sustainable management of agricultural lands.