Groundwater quality is a crucial parameter for sustainable wetland management. The evaluation of the aquifer vulnerability is important for the protection of groundwater resources. The DRASTIC model is the most significant technique for the assessment of aquifer vulnerability. This study aimed to build a vulnerability map for groundwater of the Salda Lake wetland basin by DRASTIC method in a GIS environment. Seven environmental parameters (depth to water table, net recharge, aquifer media, soil media, topography, impact of the vadose zone media, and hydraulic conductivity of the aquifer) were used in the DRASTIC method and GIS was used to constitute a groundwater vulnerability map. This study showed that 13.71% of the area had high pollution potential, 10.13% had moderate pollution potential, and 76.15% had low pollution potential in respect to groundwater pollution. Intensive agricultural activities are carried out in the study area. The DRASTIC vulnerability index value of the study area was well correlated with the nitrate map of the study area. In addition, Salda Lake protection areas were determined. All of the defining protection areas of the Salda Lake are within the most sensitive areas in DRASTIC map.