This study provides quantitative assessments for the impacts of efficiency enhancement for different types of irrigation water under water scarcity conditions. It employs a single country CGE (STAGE) model calibrated to an extended version of a recently constructed SAM for Egypt 2008/09. The SAM segments the agricultural accounts by season and by irrigation scheme; Nile water- and groundwater-dependent as well as rain-fed agricultural activities. The simulations show that Egypt should manage potential reductions in the supply for Nile water with more efficient irrigation practice that secures higher productivity for Nile water, groundwater and irrigated land. The results suggests more ambitious plan to boost irrigation efficiency for summer rice in order to overweight any potential shrinkages in its output and exports. Furthermore, even doubling all non-conventional water resources is not sufficient to compensate the potential adverse impacts of Nile water losses. This highlights the importance of irrigation efficiency for the Egyptian economy