Where Pipes Meet the Water: Urban Infrastructure in Tijuana

Tijuana's rapid urban growth and industrial development have placed significant pressure on its water infrastructure, resulting in ongoing pollution concerns in the Tijuana River Watershed and elsewhere in and beyond the city. In many areas of the city, rapid urban growth has outpaced the building of critical infrastructure like sewage and stormwater systems. These factors have left neighborhoods at risk for a long time. At the same time, industrial growth has often relied on old infrastructure or happened without the right systems in place. Although poor water quality has been a problem for years, few studies have used spatial analysis to connect the locations of sewage, water, and stormwater infrastructure with polluted areas. In this research, sewage lines, stormwater systems, water networks, pollution sites, and patterns of urban development are mapped across the city to explore the relationship between water contamination, urban infrastructure, and urban development. Using ArcGIS, spatial data on sewer lines, stormwater networks, water pipes, electrical transmission lines, waterways, vegetation, airports, industrial zones, and wastewater treatment plants were mapped alongside locations where pollution occurred in the last five years. The map shows that areas near maquiladoras, foreign-run and owned factories in México that export their product to the country of that company, as well as low-lying zones like riverbeds and canyons, tend to have the highest levels of water contamination. These include biological pollutants, such as fecal coliform and E.coli, as well as potential industrial chemicals, including Mercury and Lead. These pollutants may be connected to the fact that sewer and water systems share some infrastructure. This could be because pipes are old, not well-maintained, or the drainage systems are inadequate. However, more research is needed to confirm this link. Many industrial zones are situated near bodies of water and intersected by sewer and water lines, which increases the risk of cross-contamination through runoff, leakage, infrastructure failure, and often illegal dumping activity. This project illustrates the value of mapping infrastructure to understand better how inadequate and failing systems in specific locations might disproportionately affect communities already dealing with public health challenges, such as limited access to clean water, exposure to air pollution, and a lack of healthcare resources. These impacts often overlap with broader social and economic vulnerabilities, including the prevalence of informal or inadequate housing, underemployment, and lack of political representation, making it even harder for these communities to demand long-term, expensive, and governmentally complex solutions. At the same time, industrial expansion has relied on outdated infrastructure or developed without adequate systems in place. The findings of this research highlight why spatial mapping should be part of the discussion taking place regarding pollution in the Tijuana River Watershed.