This paper presents the application of the SWMM model to estimate the runoff due to rainfall over urban areas in Kuwait. The SWMM provides a powerful tool, in terms of its graphical capabilities and fast convergence to optimal design parameters for large urban areas. More importantly, simulation of the dynamic wave resulting from the urban runoff-transport phenomenon leads to a more accurate design for the storm drainage system, which, in Kuwait, has traditionally been based on the Rational Method. The results of this study confirm the quantitative viability of harvesting the otherwise lost runoff towards providing an additional Water resource in Kuwait. A preliminary analysis of storm Water quality also confirms its qualitative viability. A carefully designed, comparative questionnaire was used to solicit public opinion from various layers of society. The findings clearly indicate a strong public support in favor of using harvested storm Water versus recycled waste Water. Given the semi-arid nature of Kuwait, multiplicity of fresh Water resources is vital. This study presents harvested storm Water as a strong vital option. The strategic decision, vis-a’-vis the optimal combination of fresh Water resources, should be based on thorough technical and financial analyses. Resorting to the SWMM in designing storm drainage systems instead of the Rational Method will certainly minimize the ill effects of flooding, as recently experienced in Kuwait.