Theme 4-13-Agricultural data base for the sustainable use of water in the Ojos Negros valley, Baja California, Mexico.

Abstract

An agricultural data base for the Ojos Negros valley, in Baja California, Mexico, 40 km east of Ensenada, has been developed. In the past 30 years, irrigated agricultural development based on the pumping of groundwater has produced climatic, ecological, economic, and social changes in the valley. The agricultural data base represents a cross-sectional view of the economic activity in the valley; it allows the simulation of the effect of pumping at increasing depths on the profit margins of the local actors. The local actors are proprietors (ejido and other individuals) and renters (companies and individuals). Currently, the mean water table depth is 30 m; simulated depths were chosen at 40, 50, and 60 m. Results indicate that the profit margins of renters is greater than those of proprietors. The profit margins of operations, when all actors (proprietors and renters) are considered, will decrease from 27.92% at 30 m to 23.24% at 60 m. Moreover, the profit margins of the ejido proprietors will decrease from 10.92% at 30 m to 8.91% at 60 m. The number of ejido proprietors whose profit margin will be reduced to less than 5% will increase from 11 at 30 m to 18 at 60 m. With aquifer depletion continuing unchecked, the ejido proprietors will find it increasingly difficult to farm the land and will eventually resort to renting to the agroindustrial companies. If this trend persists, eventually only company renters will operate in the Ojos Negros valley, and the social fabric of the valley will have been changed completely. Aquifer regulation under the principle of sustainable development appears to be the only way out of this predicament.