Mexico temporarily discharges wastewater into Tijuana River
U.S. Section Commissioner for the International Boundary and Water Commission (IBWC) Dr. Maria-Elena Giner announced on April 9, 2025, that Mexico will discharge approximately 5 MGD of wastewater into the Tijuana River. Mexico later stated that the discharge is limited to peak hours, making the average daily impact about 3 MGD.
Mexico anticipates discharging wastewater into the river for five days, stating on April 9, as they repair a critical junction box that is part of the International Collector project.
Commissioner Giner stated in an email that it was a difficult decision for Mexico to make, as they spent days looking at alternatives. The team working on the 24/7 project felt they exhausted all other options and found a path to mitigate the amount of flow to the river from a potential of about 25 MGD to roughly 5 MGD.
The latest step of the project involves drying Junction Box #3 so it can be rebuilt with reinforced concrete. The construction requires a diversion of flow, most of which will be sent to the Mexican coast, but still roughly 5 MGD will reach the river.
The flow is expected to last for about five days, when Phase 1, the installation of the new International Collector, is scheduled to be completed.
The USIBWC requested Mexico take action to activate its PBCILA lift station to remove as much flow as possible before it enters the U.S. This pump is normally closed during the rainy season.
Commissioner Giner gave an update on April 10, stating that Mexico is trying to expedite the activation of its PBCILA lift station to remove as much of the wastewater in the Tijuana River as possible before it reaches the U.S.
