The Tijuana River watershed crosses the United States–Mexico border. Pollution, wastewater, stormwater, debris, infrastructure failures, and flows through this connected system can affect communities and coastal water on both sides.
Why this is not a one-line story
Wastewater systems, cross-border flows, rainfall, aging infrastructure, treatment capacity, public health, ecology, and enforcement all overlap. The result is a long-running problem with real consequences, but no honest single villain or simple fix.
What to rely on
For project status and agency information, see the U.S. EPA border water infrastructure program, the International Boundary and Water Commission, and California’s Regional Water Board. Those bodies publish their own mandates, records, and updates.
Our editorial standard
We distinguish documented events from hypotheses, plans from completed work, and alignment from causation. This site will correct material errors as sources change.