August 19, 2019

NADB releases full version of Tijuana River Diversion Study

  • The complete study is available at the NADB Website

San Antonio, Texas. - The North American Development Bank (NADB) has released the complete Tijuana River Diversion Study on its website, which provides an analysis of infrastructure options for managing northbound flows in the Tijuana River Watershed shared by Tijuana, Baja California in Mexico, and San Diego County, California.

The study—which includes a transboundary flow analysis, a needs assessment of the diversion infrastructure and an evaluation of alternatives for improving infrastructure operations in Mexico and/or the U.S.—identifies six top investment options to mitigate transboundary wastewater flows into the U.S.

The study was directed by NADB with funding provided by the U.S. Environmental Protection Agency (EPA) and in coordination the U.S. Section of the International Boundary and Water Commission (IBWC), the Mexican Section of the International Boundary and Water Commission (CILA), the Mexican National Water Commission (CONAGUA), and the Tijuana water utility, Comisión Estatal de Servicios Públicos de Tijuana (CESPT).

“The purpose of this study is to provide decision-makers on both sides of the border with technically feasible alternatives that have the potential to address dry-weather flows in the Tijuana River,” stated Calixto Mateos-Hanel, NADB Acting Managing Director. “We’ll continue to coordinate our efforts with all agencies and stakeholders to prioritize these alternatives and support the development of projects that address these issues.”

A total of 15 alternatives were analyzed during the study taking into consideration capital and operating costs, the anticipated reduction of transboundary flow days and the feasibility of implementation. The infrastructure investment options were ranked and the top six, along with other relevant conclusions for addressing transboundary flows, are described in the report.

The Tijuana River diversion system located approximately 1,000 feet south of the U.S.-Mexico border has been in operation since 1991. CESPT operates the diversion infrastructure through an operations and communication protocol established in coordination with IBWC/CILA.

An electronic copy of the complete study is available at


NADB is a financial institution established and capitalized in equal parts by the United States and Mexico for the purpose of financing environmental infrastructure projects along their common border. As a pioneer institution in its field, the Bank is working to develop environmentally and financially sustainable projects with broad community support in a framework of close cooperation and coordination between Mexico and the United States.