Iran, like many parts of the world, suffers from water scarcity and is located in one of the most arid regions. This is not only due to the low rates of precipitation received, but also due to the increase in demand on water resources for municipal, agricultural, and industrial uses. Wastewater reuse has proven to be effective and successful in creating a new and reliable water supply. Also, it can meet environmental needs, sustainable development, and a viable economy. There are two strategies for reuse implementation: (1) a future oriented approach allows structured planning within a broader wastewater management master plan and gives the greatest flexibility for reuse; (2) the available effluent quality from existing treatment plants defines the possible reuse option. According to the present situation in Iran, the second strategy is more reliable in preserving the country from absolute scarcity in future. Thus, the objective of this article is to understand the hidden comprehensive potential of reuse in three major categories: agricultural, industrial, and municipal uses, according to the improvement in the Falkenmark indicator.