Tijuana River
Pollution
Crisis
Billions of gallons of raw sewage cross the border every year, devastating communities from Imperial Beach to Coronado. This is an environmental justice crisis — and we're fighting back.
35 billion gallons. Every single year.
A Crisis That
Crosses Borders
Every year, more than 35 billion gallons of raw and partially treated sewage flow from Tijuana, Mexico through the Tijuana River watershed and into the Pacific Ocean. The contamination devastates beaches, estuaries, and marine life across the U.S.–Mexico border — from the Tijuana River Estuary to Imperial Beach and beyond.
This is not a new problem. It has been ignored for decades.
The communities hit hardest — Imperial Beach, San Ysidro, and south San Diego — are predominantly Latino, working-class neighborhoods. Residents breathe contaminated air, children play near toxic runoff, and local economies collapse under hundreds of beach closure days each year. This is environmental racism, and it demands a binational response.
Sewage, Justice,
and Action
The Problem
Tijuana’s aging and overwhelmed sewage infrastructure sends billions of gallons of raw and partially treated sewage into the Tijuana River watershed every year. Broken pipes, illegal connections, and insufficient treatment capacity mean toxic flows cross the border daily — contaminating beaches, estuaries, and groundwater from Imperial Beach to Coronado.
Who Gets Hurt
This is an environmental justice crisis. The communities most affected — Imperial Beach, San Ysidro, and south San Diego — are predominantly Latino, working-class neighborhoods that have been ignored for decades. Residents suffer chronic respiratory illness, skin infections, and economic devastation from beach closures while wealthier coastal communities remain untouched.
What We're Doing
Un Mar de Colores works with the Tijuana River Coalition, Most Endangered Rivers campaign, and cross-border partners to advocate for infrastructure investment, community health protections, and binational accountability. Through our MDLA program and watershed education, we train the next generation of environmental leaders on both sides of the border.
On the Ground
Frequently Asked Questions
The Tijuana River pollution crisis is a decades-long environmental disaster in which billions of gallons of raw and partially treated sewage flow from Tijuana, Mexico into the United States through the Tijuana River watershed. The contamination reaches the Pacific Ocean, closing beaches in Imperial Beach and south San Diego for hundreds of days each year and threatening public health, marine ecosystems, and local economies.
Communities in Imperial Beach, San Ysidro, and south San Diego bear the heaviest burden. Residents experience chronic respiratory problems, skin rashes, and gastrointestinal illness from exposure to contaminated air and water. Beach closures devastate local businesses, and property values suffer. These are predominantly Latino, working-class neighborhoods — making this a clear environmental justice issue.
Un Mar de Colores participates in the Tijuana River Coalition, advocates through the Most Endangered Rivers campaign, and leads cross-border watershed education programs. We train youth as environmental stewards, organize community cleanups, and push for binational infrastructure investment and policy accountability at every level of government.
You can volunteer through Un Mar de Colores by joining our watershed education programs, participating in community cleanups, or supporting our advocacy campaigns. Visit our volunteer page to see current opportunities. We also welcome donations to fund our cross-border environmental justice work.
American Rivers named the Tijuana River one of America's Most Endangered Rivers due to the scale of cross-border sewage contamination, the failure of existing infrastructure, and the disproportionate impact on environmental justice communities. The designation highlights the urgent need for federal investment and binational cooperation to address the crisis.
Join the
Fight
The Tijuana River crisis won't end without community power. Volunteer, learn, donate — every action moves us closer to clean water and environmental justice.