Program Spotlight

Los Laureles Canyon

Story by Emily To & Marie Albano

Laureles Workers

Despite the international borders that divide the United States and Mexico, the two countries share more than just common cultures and tastes for cuisine. They have also been forced to share both the environmental and public health challenges that have come with the development of man-made settlements in fragile ecosystems. In the Tijuana-San Diego region specifically, natural boundaries like watersheds are bisected by the national borders and pose unique challenges for the management of ecosystems and scarce natural resources. Due to accelerated population growth in recent years, concentrated in these unplanned settlements called colonias, infrastructure gaps in the bi-national Tijuana River Watershed have led to chronic problems of cross-border flows of sediment, trash and hazardous waste.

A prime example of this is Los Laureles Canyon in the City of Tijuana, where large populations lack many basic utilities, and the inadequate management of sewage, hazardous substances and solid waste pose chronic risks of exposure to pathogens and environmental toxicants. The streams of debris, sediment, and untreated wastewater runoff that flow across the border into the United States directly impacts California’s Tijuana Estuary nature preserve, located at the base of the Watershed. The Tijuana Estuary, the largest intertidal coastal wetland in the southern United States, is an essential breeding, feeding and nesting ground and a key stopover point on the Pacific Flyway for over 370 species of migratory and native birds, including six threatened and endangered species.

Laureles Town Laureles Road

"Los Laureles Canyon has profound urban and ecological problems," said Keith Pezzoli, a Lecturer with the UCSD Department of Urban Studies and Planning. Professor Pezzoli is collaborating with many others to boost sustainability in Los Laureles. The UCSD-TV documentary "Los Laureles Canyon: Research in Action" follows the story as Pezzoli and his colleagues tackle some of the area’s problems “which are increasingly common in low-income human settlements worldwide--we've been experimenting with new ways to join science, education and community outreach. The UCSD-TV documentary tells this story with a hopeful outlook."

Pezzoli has been working closely with Oscar Romo of the Coastal Training Program at the Tijuana Estuary and Hiram Sarabia of the UCSD Superfund Research Program. Along with other experts in public health, environmental health science, climate change and urban planning from both the U.S. and Mexico, they are documenting the San Diego-Tijuana border region’s many challenges and devising an action plan. The researchers have been testing soil samples, interacting with residents in Los Laureles Canyon, and gaining an understanding of how academic research can have a direct impact on people's lives.

Laureles Wall

Seeking to improve the quality of life in the rapidly growing human settlements of Los Laureles Canyon, UCSD students and researchers are devising proactive plans, in partnership with community groups and government agencies, to deal with serious ongoing problems of pollution and erosion of the unstable hillsides. The focus is on integrated cross-border watershed management and wetland restoration. One project involves the installation of pervious pavers on the main roads in Colonia de San Bernardo, one of the colonias situated in Los Laureles Canyon. The pavers are hexagonal shaped bricks formed from a mixture of water, cement and gravel. They will act to decrease the hazards of flooding that can devastate buildings and roadways in the canyon by regulating the flow of runoff after storms, and they will also prevent the continuous erosion of the canyon by holding in water and releasing it slowly into the ground. The natural bacteria living under these pervious pavers help bioremediate the toxicants that accumulates there. Another project involves the use of recycled tires to create retention walls for erosion control. The retention walls are designed as works of art that help the community create a sense of belonging around the public spaces.

With their continued efforts, Dr. Pezzoli and his team of researchers and student volunteers hope to improve the quality of life within colonias such as San Bernardo, and ultimately, to alleviate the environmental strains felt across the U.S.-Mexico border. Though a seemingly small step forward in the battle for sustainability, the installation of the pavers and retention walls is a true testament to how tremendous benefits may be reaped from simple solutions.

UCSD students and researchers have teamed up with Professor Oscar Romo in an attempt to scale up this type of cross-border collaboration and engaged scholarship. Professor Romo recently established a Science Center in Los Laureles which is a field-based station that provides an excellent platform for students and faculty to participate in use-inspired and problem-solving research for the community. There is ample opportunity here to link concerns about the built environment and global health.

For more information about how to get involved, please contact Oscar Romo at, Hiram Sarabia-Ramirez at, and/or Keith Pezzoli at

Organizations involved with the Los Laureles project:
The Global Action Research Center: Urban Studies and Planning Program, UCSD
NIEHS Superfund Basic Research Program (SBRP)
Center for Iberian and Latin American Studies (CILAS), UCSD
Climate Change Science at UCSD & the IPC3 Assessment Report


An extensive photo gallery focusing on Los Laureles Canyon can be viewed at

For video see the Global ARC’s Vimeo channel: