SAN DIEGO (FOX 5/KUSI) — The Tijuana River has been severely polluted for decades, impacting air and water quality for residents who live near the Tijuana River Valley, not to mention creating a foul odor that gets worse with heat.
These issues plaguing the Tijuana River have prompted nonprofit environmental advocacy group American Rivers to list the river as the second most endangered river in the United States in 2025.
The Tijuana River made the list in 2024, also due to the cross-border pollution, but the river came in on American Rivers‘ annual list of “America’s Most Endangered Rivers” in the number 9 place last year.
This year, American Rivers moved the Tijuana River up among endangered rivers in the country, behind only the Mississippi River.
Every day, up to 35 to 50 million gallons of contaminated stormwater, sewage, harmful chemicals, and trash flow down the Tijuana River across the U.S.-Mexico border and on to the Pacific Ocean in San Diego’s South Bay.
The Surfrider Foundation and Un Mar de Colores hosted a press conference Wednesday to announce this year’s designation. The press conference took place in the Tijuana River Valley near the “hotspot” where dangerous levels of hydrogen sulfide gas have been detected.
The ongoing pollution has forced the closure of Imperial Beach — the southernmost beach in San Diego County — for over 1,200 days in a row.
Just since January 1, 2025, nearly 10 billion gallons of contaminated water have flowed through the Tijuana River into the Pacific Ocean in Southern California, according to Surfrider Foundation and Un Mar de Colores.
The pollution that flows into southern San Diego County is causing health and environmental impacts for residents who live in the area. In late 2024, the CDC went door-to-door to conduct a public health survey. The results of that study found that a majority of residents said they have health concerns, symptoms and quality-of-life issues.
After a recent large sewage spill, the San Diego County Air Pollution Control District is giving out free air purifiers to those who qualify.
In the latest turn of events, EPA Chief Lee Zeldin will be visiting the U.S.-Mexico border in late April to see firsthand the impacts of the sewage crisis after years of repeated calls for action from the federal government.
10 Most Endangered Rivers in the United States, by American Rivers:
American Rivers said their message is “to stop the cycle of destruction, we must invest in solutions that protect river health and our nation’s clean water security.”
2025 also marks 40 years of America’s Most Endangered Rivers, as American Rivers highlighted some of the most impactful stories of challenges rivers face and some solutions they have been able to achieve.
