Although flood and drought have ceaselessly taken place, recently the scale of disasters by them has become incomparably bigger than that of the past, and frequency of flood has rapidly on the increase (Harim et al, 2013). According to National Emergency Management, the frequency of torrential downpours over 30mm per hour was average 3.8 times for last 30 years and average 5.2 times for recent 5 years. Number of days with localized torrential downpour over 80mm per day has increased by 1.5 times for the same period. In addition, recently with the change of climate in Korea, the severity of drought has intensified in 6- to 7-year cycle and, with such reasons as excessive intake of stream water, streams are drying up, especially during spell of dry weather (Maeng, Seung Jin et al, 2013). Even though the government, as countermeasures for these problems, has made efforts to prevent disasters by establishing Water Resources Integrated Development 10-year Plan and Water Resources Long-term Integrated Development Plan, implementing Stream & River Improvement Projects and constructing multi-purpose dams, there are difficulties to promptly cope with rapidly changing weather conditions, requiring urgently measures to minimize damages from droughts and floods. This study developed Portable Multi-purpose Water Barrier (Pocket Dam) which can promptly cope with floods and localized torrential downpour, secure agricultural water by temporarily blocking irrigational channel and drainage during drought and has wide applicability to various areas. To develop Portable Multi-purpose Water Barrier, this study i) selected ultra-light materials for easy mobility ii) chose optimum standards applying MIDAS program iii) verified safety features through field applications. For the maximization of blocking effect as well as the lightening of product, Sol Tarpaulin (PVC-coated polyester) was selected that has endurance against water pressure and excellent gripping force on irregular ground bottom. In addition, by using 3-dimensional structural program MIDAS, the barrier was designed in such a structure that it will not be destroyed or pushed behind by water pressure. As the result of the application of developed barrier on Dorim stream in Gwanak-gu and underground parking lot in Kwangjin-gu, Seoul, the barrier was not destroyed or pushed behind, and, instead, it maintained constant standing position and blocked water, proving that it has diverse applicability in addition to safety features in structure and material.