The $5.8 million San Diego County supervisors approved Sept. 1 for the Tijuana Sewage Crisis won’t build a sewage treatment plant. It funds design and engineering work — the first step, supervisors say, before the county can chase the hundreds of millions of dollars an actual fix will cost.
Supervisors approved the funding in a 4-1 vote, framing it as San Diego’s answer to decades of waiting on Mexico and the federal government, according to its champions, Supervisors Terra Lawson-Remer and Paloma Aguirre.
The money will fund design for a permanent box culvert fix at Saturn Boulevard and engineering work on a capture and cleanup system that Aguirre described as the first infrastructure the county would build to capture and treat river flows directly, on U.S. soil.
Supporters say it is easier to secure funding through grants and financing with a plan in place than it is to chase money with a vague idea.
Aguirre and Lawson-Remer both said too much time had passed waiting on a fix from the federal government and Mexico, and said it was time for the county to build its own infrastructure.
But the sole vote of dissent came from Supervisor Joel Anderson. He supported the Saturn Boulevard project with a qualm — that he would feel more comfortable if there were a regional coalition of cities supporting it, naming Coronado, Imperial Beach, and San Diego specifically as communities he’d like to see involved.
Then, Anderson voted against the capture and cleanup system, saying the county shouldn’t interfere in matters that belong to the federal government (which operates infrastructure in the U.S. that treats Tijuana sewage).
“This is Mexico’s fault, and if anything, a treatment plant should be built on their side of the border, not on our side of the border,” Anderson said. “We’ve already built one to the tune of $650 million, and that’s just the cost of building it, not the operating costs.”
Anderson had a different idea for a quick change: cutting off water supply to Mexico historically delivered via the Otay Water District.
“I’d really like to see a coalition talk to (Mexico) about withholding the water,” Anderson said. “If you’re going to send it back to us polluted, then we’re just not going to give it to you to start with. I think that focal point is our real leverage because it’s hard to grow Tijuana if there’s not enough water to grow Tijuana.”
Though Anderson framed it as the U.S. selling water to Mexico, it’s more complicated than that: The Otay Water District delivers Mexico’s own water from the Colorado River, guaranteed under the 1944 U.S.-Mexico Water Treaty.
The water is delivered to Tijuana through a cross-border connection in Otay Mesa during droughts and emergencies, using infrastructure jointly run by the Otay Water District, the San Diego County Water Authority, and the Metropolitan Water District of Southern California. Mexico pays transportation and infrastructure/meter-upkeep costs, not a market price for the water itself, since the water is technically already theirs by treaty.
The volume varies by year, with a steady increase: in 2018, Otay delivered 293 acre-feet, which rose over the following years, spiking to a record 3,215 acre-feet in 2022, at a cost to Mexico of about $4.3 million.
The U.S. has withheld this water before: In 2025, the U.S. refused to deliver emergency water to Mexico, saying it was not upholding its end of the treaty, which requires Mexico to send 350,000 acre-feet of water to the Rio Grande as the U.S. sends 1.5 million acre-feet from the Colorado River. Baja California’s water officials responded that they’d “taken measures” to manage without it.
Later that year, Mexico delivered its owed water. To Anderson’s point, then, withholding water is not without precedent.
Regardless, Lawson-Remer and Aguirre said that while the pollution may be Mexico’s fault, the consequences are being felt by South Bay residents, and someone has to act.
The rest of the board supported the funding. Vice Chair Monica Montgomery Steppe supported both projects and called the move groundwork for “a locally controlled treatment system on the San Diego side of the border.”
Supervisor Jim Desmond voted in favor, but said a treatment plant should be on Mexico’s side of the border. He backed continual pressure on Mexico, including tariffs and sanctions.
Where will the rest of the money come from?
Any resulting projects from the design and engineering process will cost millions, at least.
Lawson-Remer said the county’s long-term plan hinges on the same financing model used for large public infrastructure elsewhere. For example, the $900 million Terminal 2 expansion at the San Diego International Airport was financed in part by bonding against future airport revenue. (It was also funded by airport cash reserves, FAA grants, and passenger use fees.)
Lawson-Remer said the day before the vote that if the county secured about $80 million a year in guaranteed revenue, it could bond against it to raise close to $1 billion for treatment infrastructure.
Of course, the revenue would have to exist. One potential source is a countywide ballot measure this November that would raise the sales tax by a half-cent. It’s known as the Protect San Diego County Health and Safety Act, and revenues from it could be used for matters of public health — including mitigating the ongoing sewage from Tijuana. Supporters project the measure would generate roughly $360 million a year, with 22 percent, or about $80 million annually, dedicated to Tijuana River pollution solutions if voters approve it.
Both supervisors said they were not taking a position on the measure and are pursuing state and federal funding regardless of its outcome. Lawson-Remer pointed to the county’s $100 million Behavioral Health Hub as a precedent for designing a project before its full funding is secured.
During the Sept. 1 board meeting, one public commenter questioned the ethics of pointing to an upcoming ballot measure as a potential source of revenue, and the concern about legal boundaries around ballot measure advocacy isn’t hypothetical.
In August 2026, California’s Fair Political Practices Commission fined Nevada County $31,500 after finding it illegally spent public funds to promote Measure V, a 2022 sales tax measure. The county had used a $17,708 special appropriation from its Office of Emergency Services to mail campaign materials to 33,351 residents just weeks before the election. The FPPC found the mailer’s “affirmative statements” urging support, combined with its timing so close to the vote, crossed the line from permissible voter information into illegal campaign advocacy.
During a press conference announcing the planned spending, Aguirre said the board wasn’t “advocating one way or another” on the measure. However, she and Lawson-Remer spent several minutes at the presser detailing exactly what a “yes” vote would deliver: roughly $80 million a year dedicated to Tijuana River solutions, which Lawson-Remer said the county could bond against for close to $1 billion in treatment infrastructure.
Whether that’s advocacy or information is a distinction the FPPC has drawn a line around before; it’s also one voters can weigh for themselves.
Regardless, the board’s action also converts its ad hoc Tijuana River subcommittee into a standing one, with public updates required at every phase.
“We can’t control what happens across the border, but we can control what we do on our side of it,” Aguirre said at the meeting, “and you can hold us to it.”
