In the preparation of the New Jersey Statewide Water Supply Master Plan, a large quantity of water related data was compiled from previous studies, water regulatory agencies, and individual water purveyors. The data relates to both water supply and demand and will be used to determine areas where water deficits exist in the state. Lotus 1-2-3, a popular 3-dimensional spreadsheet program, is being used to develop a Database/Water Balance Model (DB/WBM) for the state. The model will be used to summarize and present various water supply and demand parameters as well as to calculate the water deficits themselves. The intended use of the DB/WBM is to determine the areas in the state that will experience initial deficits so that projects and programs can be evaluated that will avoid these deficits. This paper gives background, a brief overview of the design of the spreadsheet, and two possible uses of it.