A relatively simple ground water decision support system (DSS) was developed to assist in identifying salt water vulnerable areas and in developing management policies to prevent salt water intrusion in central Kansas. The DSS is based on a combination of numerical modeling sensitivity analyses, multiple regression analyses, and classification procedures derived from our knowledge of the area. Six ground water salinity models are proposed to evaluate irrigation well permit applications. The choice of model depends on the availability of site-specific data. The DSS takes advantage of GIS database management procedures, and is applied to an actual salt water intrusion problem site in south-central Kansas. This approach can help local ground water management districts make better decisions on protecting ground water use in salt water vulnerable areas.