ABSTRACT
This study was developed in Mexicali, Mexico, in conjunction with the State of California, USA.The climate region is arid and rain is low (6.5 cm/year); irrigated land of 207,965 hectares and 16,128 farmers with water rights. Urban water users include 3.5 million inhabitants. Water demand is critical. All users ask for more water everyday. In front of the enormous water demand, authorities have been specified rationalization approaches that allow obtaining better supply conditions to a bigger number of people (Roman, 1991). Competition for water among cities, industry and agriculture, is increasingly difficult (Roman, 1991). Beginning with the rise in the price of water and the subsequent shortage, it suggests a dilemma for analysis, how to supply more users with less water, becoming an economic principle that has existed for a lifetime (Roman, 2003; Comision Nacional del Agua, 2001). Nowadays, water acquires a bigger economic, political, and social value, as a part of an intense process of productive competition; it means that until now, the worst part of this new balance has corresponded to agricultural activities.
