Tijuana River Border Barrier Flood Hazard Analysis Technical Report

Customs and Border Protection (CBP) intends to install a 900’ border security barrier across the Tijuana river channel, immediately downstream of the US-Mexico border. The planned barrier is composed of a steel structure, anchored to the Tijuana River channel by four 72” columns. The steel structure will house approximately fifty three individually hoistable gates, designed to be lowered during low river flow and raised during high flow. The bottom 5’ of each gate is impermeable and the remaining 25’ are approximately 40% permeable. In the case the gates remain in the lowered position during high flow, they would allow conveyance of approximately one-third of channel flow, assuming no further blockage from debris.
The purpose of this effort is to model flood hazard from the proposed river barrier bridge and gates in order to address concerns that flooding could impact US government funded wastewater infrastructure projects including the South Bay International Treatment Plant and Tijuana-side wastewater pumps and collectors. This modeling is in alignment with the Federal Flood Risk Management Standard, which requires agencies to prepare for and protect federally funded projects from flood risks. This standard recommends modeling for a 500-year storm event. This will help understand, plan for, and mitigate potential flood risk from the barrier, under various flow events and operational scenarios.

Report File