The threat of flooding is a serious concern to local governments that are responsible for flood protection. This paper presents a study that provides an effective integrated flood warning system. GIS, hydrologic models, emergency response strategies, and expert knowledge are integrated in this system to provide a typical application that begins with user input of current water levels and area of interest. The system then returns graphics and reports delineating the potentially affected area. The methods and techniques will be discussed in detail in this paper.