One of North America’s Most Polluted River Systems Set to Receive $46 Million in Cleanup Funding

Governor Gavin Newsom has announced $46 million in voter-approved funding to address the ongoing water quality crisis of the Tijuana River at the California-Mexico border.

The new funding, approved by California voters through Proposition 4, adds to the $38 million the state has already committed to address pollution affecting the communities living along the border, Governor Newsom said in a statement on June 11.

Urging the Trump administration to take responsibility for repairs to the federally managed wastewater infrastructure at the center of the crisis, Governor Newsom said California cannot solve a “decades-long federal failure” on its own.

“People in San Diego County shouldn’t have to worry about getting sick, losing access to their beaches, and living with polluted air,” Governor Newsom said.

The State Water Resources Control Board on Thursday opened the grant application period for the $46 million program. The funds will be available for eligible projects that address contamination in the cross-border rivers and coastal waters, according to the governor’s office.

Under the program, at least one project from both the Tijuana River and the New River will be selected for funding.

Planning and research projects may receive grants of up to $750,000, while implementation projects may receive up to $10 million.

The maximum award for implementation projects could increase to $20 million with approval from the State Water Board’s deputy director.

No more than $3 million of the total funding will be allocated to planning or research efforts.

Projects include those that reduce bacteria or trash, address public health issues associated with transboundary pollution, and support restoration and mitigation, and sediment management.

The announcement comes as California continues pressing the federal government to establish a permanent solution for the Tijuana River crisis.

According to the governor’s office, the federal government is responsible for the International Boundary Commission’s South Bay International Wastewater Treatment Plant in San Ysidro, which treats water flowing through the Tijuana River.

The facility has failed to adequately address the problem despite a commitment by EPA Administrator Lee Zeldin in July 2025 to deliver a “100% solution,” according to the governor’s office.

Severely Polluted River

While about three-quarters of the Tijuana River Watershed lies in Mexico, it drains into the Pacific Ocean through the eight-square-mile Tijuana River Valley north of the border in California’s Imperial Beach, according to the California State Lands Commission.

The watershed is filled with untreated wastewater flows, contaminated sediment loads, and trash influxes, which, in turn, affect the environment, nearby communities, and the public health and safety of the region.

In its annual report identifying the worst beaches in California, Heal the Bay listed the Tijuana Slough at the Tijuana River Mouth in San Diego County. The water is severely contaminated by the wastewater pollution originating from Baja California, according to the organization.

According to the governor’s office, pollutants accumulate in Smuggler’s Gulch, a collection system with gates to intercept and divert trash before it flows into the Pacific Ocean.

While discharges from U.S. sources are treated and disinfected to meet state and federal standards, the water entering the country is filled with raw sewage, industrial, domestic, and agricultural waste, trash, and other solid pollutants.

Efforts by Governor Newsom in 2024 to secure federal support resulted in an additional $100 million federal investment for the treatment facility, according to the governor’s office.