Wastewater Management and Environmentalism at the San Diego–Tijuana International Boundary during Mexico’s Border Industrialization Program, 1965–85

This paper examines the problem of sewage and industrial waste in the binational Tijuana River on the U.S. Mexico border during the first twenty years of Mexico’s Border Industrialization Program (1965-1985). During these years, American-owned maquiladoras (assembly plants) drove rapid population growth in the Mexican border city of Tijuana. Sewage and industrial toxins south of the border spilled into the northbound Tijuana River, polluting public lands and properties downstream in San Diego. In 1967, the International Boundary and Water Commission of the United States and Mexico (IBWC) agreed to construct a concrete channel on the Tijuana River. While intended for flood control, the channel was also expected to help the IBWC solve the pollution problem. However, before construction began on the U.S. portion of the channel, environmental groups in San Diego blocked the project and established a California state park, preserving the Tijuana River Estuary as a wildlife habitat. The channelized river south of the border then served as a projectile for pollutants from Tijuana into the wetland habitat on the U.S. side. Therefore, the conservation of the estuary was both a win and a loss for the environmental movement, showing the limitations of environmentalism in a river basin divided between two sovereign and unequal nation-states. This paper shows that, while Americans blamed Mexico for the pollution of San Diego’s estuary, it was American-owned maquiladoras that drove Tijuana’s rapid urban growth and fueled the environmental hazard downstream in the United States.