Water is an important substance for human kind and other survivals on the earth due to its role for their growth, survive, and activities. For that, it covers more than seventy percent of the earth surface and human body weight. But, unfortunately most of the water is saline and available fresh water doesn't increase one percent. Earth is divided into four zones based on the rainfall amount and meteorological factors known as humid, semihumid, semi-arid, and arid. Their annual rainfall more than 600 mm , 300 – 600 mm , 100 – 300 mm , and less than 100 mm respectively. Jordan is located in semi arid region which faces day by day a shortage of rainfall and fewer amounts of surface and groundwater. These conditions force the public sector to work hard for obtaining new water resources in order to match the incremental of population growth and water demand. Dams consider preferable structures of collecting surface water and recharging ground water during winter season .But, it needs a lot of study and using latest fashions of tools and technology for site selection and dam construction in order to reach required goals with proper means. Remote sensing and geographical information system consider suitable tools of collecting, input analysis, and output data. Wala dam was the attractive one to study the necessary selecting parameters of site selection by using these tools in popular way for planners and decision makers in Jordan