We evaluate the structural consequences of water availability scenarios in the Mediterranean, following a bottom-up methodology. This includes an assessment of future water availability and a general equilibrium analysis of changes in agricultural productivity. Lower productivity in agriculture, induced by reduced water availability, generates negative consequences in terms of real income and welfare. The magnitude of the loss depends on the amount of the productivity shock, but also on the share of agricultural activities in the economy and on the stringency of the environmental regulation. Our results suggest that countries in Middle East and North Africa could respond to increasing water scarcity by accepting, to some extent, lower environmental quality (deterioration of aquatic environments). Furthermore, improvements in water efficiency appear to curb the economic impact of water scarcity quite significantly, especially for northern Mediterranean countries.