In response to the growing concern on environmental assessment in dam management in Japan, using numerical simulation technologies, it is often required to comprehend the dynamic features of the water (sea, lakes, rives, ice, evaporated water, etc) which is the basis of material transport system as well as eco-system. In this research, we provide an overview for the development of the simulation programs applied to Haji Dam watershed as a case of study which is required a deeper assessment due to the increasing decay in water quality originated by human activities inside the watershed. In order to demonstrate how this techniques could be use in the future to assure a better information management we will introduce a series of programs in Asian Environment Simulator (AES) which will be used to achieve the highest response to human efforts.