As of February 2025, the United States has allocated approximately $1.1 billion to address the Tijuana River pollution crisis. This funding is primarily directed towards upgrading and expanding the South Bay International Wastewater Treatment Plant (SBIWTP) to mitigate transboundary pollution affecting Southern California communities.
Funding Breakdown:
- $300 million from the United States-Mexico-Canada Agreement (USMCA) in 2020, designated for infrastructure solutions in the Tijuana River watershed. 
- $103 million secured in early 2024 for the International Boundary and Water Commission (IBWC) to support the SBIWTP’s repair and expansion. 
- $250 million allocated in December 2024 through the Further Continuing Appropriations and Disaster Relief Supplemental Appropriations Act of 2025, providing the final tranche of funding required to complete the SBIWTP upgrade project. 
- $310 million requested by President Biden in November 2024 for the Tijuana River Valley region, aimed at repairing and expanding the SBIWTP. 
- $156 million approved by the U.S. House of Representatives in March 2024 for water quality construction projects under the IBWC’s budget.
Project Timeline:
The SBIWTP upgrade project commenced in October 2024. The expansion aims to double the plant’s capacity from 25 million gallons per day (MGD) to 50 MGD, with peak flow capacity reaching 75 MGD. The project is designed to be completed in phases over approximately five years, with efforts to expedite the process through concurrent design and construction. 
Sewage Discharge Volumes:
Tijuana’s sewage infrastructure has faced challenges in managing wastewater, leading to significant pollution in the Tijuana River. The San Antonio de los Buenos treatment plant in Tijuana has been discharging nearly 40 million gallons per day of raw sewage onto a Tijuana beach and into the Pacific Ocean for years, contributing to the chronic contamination of coastal waters and local beaches. 
Additionally, during large rain events, the flow rate in the Tijuana River can reach several billion gallons per day, significantly increasing the volume of untreated wastewater entering the river and affecting downstream ecosystems and communities. 
These combined efforts and investments reflect a comprehensive approach to resolving the longstanding environmental and public health challenges posed by the Tijuana River pollution crisis.