The $25 million toe in the water

A $25 million reconstruction of the Saturn Boulevard culvert aims to stop sewage-laden water from spewing toxic gas into the air, offering near-term health relief for South Bay residents.

Flooding along the Tijuana River turned Saturn Boulevard into a hazardous corridor on November 21 , 2025, after a heavy rainstorm in San Diego.

The overflow highlighted a long-standing problem: outdated culverts under the road force sewage-laden water to burst through, releasing hydrogen sulfide and other toxic compounds into the surrounding air.

An echo of Sydney's 2024 institutional buy-up

A larger binational effort seeks $800 million for wastewater-treatment upgrades on both sides of the border.

San Diego County Supervisor Paloma Aguirre and other leaders are lobbying for roughly $25 million to redesign the culvert system, replace the aging concrete pipes and install modern flood-control structures that would keep sewage water from spraying into the atmosphere.

The proposed engineering overhaul would channel runoff safely away from the road, eliminate the foam-forming discharge and dramatically cut emissions of hydrogen sulfide, which has been linked to asthma attacks, stomach upset, skin irritation and chronic headaches among nearby families.

Who is the unnamed buyer?

Funding for the project is being pursued through three avenues.

First, Proposition 4 - the $10 billion climate-bond measure approved by California voters in 2024 - earmarks about $50 million for bodrer-river projects, including up to $20 million that could be awarded to the Saturn Boulevard reconstruction after a competitive grant process later this summer.

Second , state lawmakers have included a $23 million line item in the 2026 budget that, if approved, would cover most of the construction cost and free bond dollars for other cleanup work such as sediment removal and trash capture on the Tijuana and New Rivers.

Third, a proposed half-cent sales-tax initiative, the Protect San Diego County Health and Safety Act, will appear on the November ballot and could generate $360 million annually, with about $80 million earmarked for Tijuana River mitigation.

What auditors flagged in the May filing

While the tax measure does not specify the Saturn Boulevard project, it creates a flexible pool of resources for environmental health interventions.

In the interim, a temporary mitigation plan costing $2.5 million could be installed within a year, providing immediate relief by capping emissions and stabilizing flood flows until the larger construction begins.

If San Diego leaders can secure the needed $25 million and navigate the funding streams , the community could see a tangible improvement in air quality and a reduction in the chronic health issues that have plagued the region for decades .