The Rodriguez dam holds a massive reservoir at the edge of Tijuana where the mountains give way to the city’s urban expanse. Its water flows for kilometers to the U.S.-Mexico border through a concrete channel. But just below the dam lies a dense patch of virile green land.
There, Liliana Esparza and her team from the Mexican environmental nonprofit Pronatura Noroeste have been rehabilitating this section of the river overlooking the Cerro Colorado, a well-known landmark in east Tijuana. The project, Tijuana Río Conecta, seems implausible: burgeoning native plants feeding on a stream of partially treated wastewater from a nearby plant.
“It’s a green lung that we are trying to restore,” she said in Spanish.
Esparza is one of many carrying out projects throughout the Tijuana River watershed with the goal of restoring its health. The watershed, which spans parts of San Diego County and Baja California, has absorbed 100 years of population and industrial growth. Most recently, the region has been marked by sewage overflows affecting residents in Tijuana and San Diego’s South Bay communities.
From cleanups to education, political advocacy to legal actions, generations of stewards are pushing for solutions to the pollution crisis.
Here are a few of the many working on restoring the Tijuana River’s health:
Beyond borders
For more than three decades, Margarita Díaz led the Proyecto Fronterizo de Educación Ambiental, an advocacy group based in Playas de Tijuana. Díaz organized beach cleanups and a water testing program to inform residents about water quality along Tijuana’s beaches.
For years she has fought to hold leaders in Tijuana accountable for broken infrastructure and contaminated water in the region. She has also built relationships with advocacy groups in the U.S., insisting that collaboration is crucial to address the pollution crisis. Many of the problems in the watershed exist because it was artificially cut by the border, she says.
“We are one coastal community. You cannot see San Diego without Tijuana. You cannot see Tijuana without San Diego,” she said. “They need us. We need them. So we have to work like that.”
Her work has inspired new generations of waterkeepers.
Waylon Matson says his work has left him with one undeniable truth: “We’re only as healthy as the water that we’re surrounded with.”
His organization, 4 Walls International, has advocated on the cross-border issues for more than 15 years.
Years ago, while working with communities tucked into Tijuana’s canyons, Matson saw the impacts of heavy waste flows on residents – children enduring persistent skin infections and illnesses. Those experiences, he said, revealed how environmental neglect becomes a public health emergency.
Lately, Matson has been working to develop policy to secure funds for Tijuana River pollution-related needs.
“I learned how to farm in the river valley. I learned how to surf in Imperial Beach,” Ramon Chairez said.
Now Chairez advocates for the river and his community as a part of Un Mar de Colores, an organization focused on fostering new stewards among youth from communities that have faced barriers to accessing the ocean.
Having felt sick himself from breathing the sewage gases, Chairez says he’s appalled at how long his community has had to live with the impacts.
The pollution is the result of a long history of exchange across the border for which everyone in the region, including the businesses that have benefited, need to take responsibility, he said, adding that he sees it as his role to help ensure people in power are aware of community concerns. It takes a lot of work to inspire change, he said.
“If you’re not pushing from the bottom, then whoever’s at the top is not going to respond,” Chairez said.
A trinational estuary
An artist who leads cultural programming for the San Pasqual Band of Mission Indians, Johnny Bear Contreras collaborates with researchers in the estuary to connect their work with the Kumeyaay community.
So far that has resulted in more cultural programs involving the Indigenous community, including a public art event closing the Tijuana River action month.
The Kumeyaay, which includes the San Pasqual Band of Mission Indians, have been connected to the coastal lands since time immemorial, he said. “These connections to the waterways are a way of life, always has been.”
The Kumeyaay have stewarded the valley for more than 10,000 years, forming techniques to work with the river. They devised land management practices to regulate sediment buildup. They controlled erosion with specific crops.
When the conquistadores arrived, they did not recognize Kumeyaay management techniques, but today, those techniques could be revisited to help reverse the harm done in the river valley, Contreras said.
“It’s wonderful to know your customs and traditions, but where these things don’t always match what needs to be done, as the native person you have that right to extend on your customs and traditions, to create the practices that best help.”
Kristen Goodrich has worked for 16 years supporting solutions for wetlands restoration and coastal resilience at the Tijuana River National Estuarine Reseach Reserve, located in the South Bay.
Over time, she’s come to see the estuary as a place where the environment intersects with public and mental health. The border region is a “really traumatized environment,” and fixing the environmental issues could lead to better health overall, she said.
“If we can support protecting the Tijuana estuary,we can also provide opportunities for people to heal as well.”
But rather than focus solely on how people can benefit from a healthy estuary, Goodrich would like to see the community develop a reciprocal relationship with the land – something researchers can learn from Indigenous wisdom, she said.
“This has been a way of being for millennia for our Kumeyaay communities,” Goodrich said.
Goodrich says she has a vision for a trinational leadership community, bringing together environmental stewards from the U.S., Mexico and the Kumeyaay.
Shanasia Sylman, a graduate student at Cornell University, relocated to San Diego in 2024 under a research fellowship funded by the National Oceanic and Atmospheric Association. She works at the reserve with Goodrich. Her research focuses on the Land Back movement, an Indigenous-led effort to reclaim ancestral lands, as well as reparations for Indigenous communities.
At the estuary she is researching ways to introduce Indigenous knowledge systems into restoration efforts, given the Kumeyaay are the “generational caretakers” of the region. To begin, she and her team have set out to build trust with Kumeyaay community members.
One way of doing so, she says, is to incorporate more language in the center’s public facing exhibits and events acknowledging Kumeyaay history and connections to the river valley.
The reserve has adopted the use of the word “trinational” to describe watershed.
“So ‘trinational’ is opening the door to have those conversations more broadly,” Sylman said. “What does it mean to see these places as Indigenous places first, and see them as spaces that are going to affirm Indigenous knowledge and cultural practices?”
The language stimulates people to think differently, she said.
“If we think about restoring the estuary, yes, it’s about improving the water quality to some degree, but all of that is still tied to reconnecting people to place.”
Swipe to meet more stewards of the Tijuana River Valley.
