By Ioana Patringenaru
Oscar Romo is walking on a dirt road just a few miles away from the U.S.-Mexico border, the ground crunching softly under his feet. It’s a typical sunny day in the Tijuana River estuary. Birds fly by. Families walk on the beach. But Romo is worried.
The UCSD researcher points to a patch of vibrant dark-green grass to his left. This, he explains, is a salt marsh, the healthy part of the estuary, where native species thrive. He then turns to a patch of hard, cracked light-brown dirt to his right. This, he goes on, is sediment that came across the border from Tijuana and is choking the marsh. All this sediment is threatening the estuary and, by extension, the health of the beaches, plants and wildlife in this corner of San Diego County.
The estuary stands as the last barrier between the Pacific Ocean and pollution, Romo adds. Its mix of plants and silt acts as a filter that purifies inland rain and flood waters before they reach the ocean. The beaches of Imperial Beach are closed about 180 days every year. Without the estuary, they would be closed year round, he says.
“It’s not just a case of nature serving nature,” he says of the estuary. “It’s nature serving us.”
Preserving the estuary, the largest coastal wetland in Southern California, has been Romo’s mission and passion for years. He works at the Tijuana River National Estuarine Research Reserve, where he coordinates the Coastal Training Program, a federally sponsored effort to educate decision makers. The reserve is home to five species of threatened or endangered birds. Its waters act as a nursery for several species of fish and shellfish.
Romo is also a lecturer in the urban studies and planning department at UCSD. When he’s not on campus or at the estuary, he hosts a Spanish-language talk show titled “Ocean Without Borders.”
His quest to stop the flow of sediment that is choking the estuary has led him to Los Laureles Canyon in Tijuana, known in the United States as Goat Canyon. The community is part of the Tijuana River’s watershed and is home to about 80,000 residents, most of them squatters. They live in makeshift homes, with foundations sometimes made out of tires and walls made out of garage doors. “There is no planning, there’s no roads, there’s no power, there’s no sewers,” Romo says of the shantytown.
“So, it’s a second-hand town,” he adds. “Everything has been used by somebody else before.”
The lack of infrastructure means that sediment, organic waste and solid trash, including mattresses, car parts and fridges, end up in the estuary, via a drainage channel. When storms hit, flood waters rage down the badly eroded canyon, wiping out homes and occasionally killing residents. Then the sediment washed down from storms kills the wetlands below the canyon.
As much as five feet of sediment can now accumulate in one year, up from a small fraction of an inch in previous decades, Romo said. To solve the problem, the California Coastal Conservancy and the California State Parks built vast basins, where sediment could accumulate. But catastrophic storms in 2004 and 2005 filled them well beyond capacity. The key to keeping the sediment at bay today is to enroll the help of the Los Laureles’ residents themselves, Romo said.
“We need to bring solutions to their problems that also solve our problems,” he said.
Tijuana River estuary and Coastal Conservancy authorities, the City of Tijuana and the nonprofit International Community Foundation are now working on a bi-national effort to do just that.
As part of this project, Romo and his UCSD students have set their sights on improving life in Los Laureles canyon and the university has been providing technical assistance and funding for their efforts. One of their most ambitious projects aims to build 40 sustainable homes from the ground up in the canyon. So far, the project has raised enough funds for three dwellings. The homes will be made of bamboo, which UCSD students suggested as a construction material because it can grow locally, Romo said. A micro-sewage plant that will treat wastewater from the neighborhood also is in the works.
Meanwhile, UCSD students and faculty have set up a nursery in the canyon to bring back native plants that have been driven away by erosion, floods and construction. Romo said he hopes local residents will then take ownership of that project. Finally, about 70 community meetings have taken place in the canyon. Residents learned about the risks associated with waste water and trash, Romo said.
In a way, the estuary’s issues reflect all the water issues going on in the region, said Nina Jean Thurston, a student at the School of International Relations and Pacific Studies at UCSD. She works as Romo’s assistant at the reserve.
Being able to help solve these problems is an incredible opportunity, she said. “I work on both sides of the border,” she said. “I see how people live on both sides of the border. I meet with decision makers on both sides of the border.”
She added she believes she can make a difference. Romo echoed her optimism. With many projects under way, he said he believes bi-national cooperation, education and good urban planning can save both the Tijuana River estuary and Los Laureles Canyon.
“We’re trying to save the world, one sub-basin at a time,” he said.