The impacts of growth of global population changes in economic environment have more pronounced effects on Middle East and North Africa countries. User friendly hydrological computer software packages have proven to be helpful tools in managing precious water resources. Watershed models have been successfully used to perform complex analyses and to make informed predictions concerning consequences of proposed actions. They also increased the accuracy of estimates for alternative practices to a level beyond human best judgment decisions. In this paper, we describe A User-Friendly Computer Based Water Management Software Package, GIS-IManSys. This package was developed using two object oriented high level programming languages, Java and Visual Basics, and a spatial geo-spatial analysis software, ArcGIS.9.2. This version of the software package is intended to be a teaching tool for different specialized users interested in water resources management; it also targets educators and students from different scientific disciplines, regular people who want to have level of understanding of water management at different land scales ranging from small plots to large areas. The graphical user interface has been improved to help the users easily interacting with the program and take advantage of its capabilities. GIS-IManSys has been successfully calibrated and validated using different data sets.