The Tijuana government plans to preserve one of the city’s last surviving river habitats, a 2½-mile stretch of Arroyo Alamar.
Years of requests by residents and environmentalists have halted city plans to pave over the last green section of Arroyo Alamar, a creek that once ran for six miles through Tijuana and is now largely filled with concrete.
Mexico’s National Water Commission and other government agencies agreed to hear the concerns of community members. They formed a joint government and community advisory committeeearlier this year.
Jorge Calderon lives near the Arroyo Alamar where cottonwoods, butterflies and lizards still thrive. On a recent Saturday, trekking through a rain of pollen, he led a tour through the Arroyo to identify the habitat’s wildlife.
“It’s about more than preserving a park,” Calderon said. “It’s an ecosystem. It’s a school for my grandchildren, for my children.”
The habitat includes plants with curative properties that low-income locals use as medicine or food: the cardo mariano, the hierba de manso, the uña de gato.
"Look how beneficial it is," Calderon said, looking around.
More than half of the Arroyo is now paved over, turning it into a concrete channel. Officials have said the final section needs to be turned into a channel, too, but they are willing to consider environmentally friendly alternatives to concrete, such as rocks. Those might allow surrounding vegetation to survive.
In the 1990s, floods destroyed hundreds of houses and caused more than a dozen deaths along the river. The Tijuana government started turning the Arroyo Alamar into a channel in part to protect people from floods.
The city also needs to pave over the final section of Arroyo Alamar to connect two main highways and prepare for the construction of Otay II, a port of entry planned for 2017. The new border crossing is expected to increase trade between the U.S. and Mexico.
Resident Ana Langarica said the channelization of the river divided the community. To visit her relatives and friends, she used to cross a small makeshift bridge over the creek. Now, she has to take a long detour or cross the canal and highways.
“In 10, 15 minutes I was already at my destination. Now it takes me half an hour or 40 minutes," Langarica said.
She said the divide also made her neighborhood more dangerous. She has seen pedestrians getting hit by cars when trying to cross the canal, she said.
Langarica has fond memories of living across Arroyo Alamar when it was green. Her family harvested plump watermelons and sweet maize that grew on fertile soil along the riverbanks. They roasted the maize, cut up the watermelons, captured fish and went swimming.
“Mm, what did I like? Everything!” she said.
Now, her house is noisy with the sound of traffic.
Numerous families live around the creek in makeshift homes with wooden planks and corrugated tin. Not all of these communities were formed legally, and the government has sporadically removed people living too close to the water. Government officials have pointed to the encampments as causes of a worsening pollution problem in Arroyo Alamar.
But the creek is also downstream from Tijuana’s maquiladora zone. Mexico’s National Water Commission has reported finding toxic metals and chemicals in the water. Residents near the canal have taken photographs of neon blue waters running through the streets.
Experts said the Arroyo in its natural state filters part of that pollution.
“Riparian vegetation serves as a bio-filter for certain amounts of pollution," said Cesar Garcia Valderrama, president of the Baja California chapter of the California Native Plants Society.
Paving the creek with concrete would increase hazards to environmental and human health north of the border as well as in Tijuana, Valderrama said. The arroyo connects with the Tijuana River, which feeds into the ocean and a sensitive estuary on the north side of the border.
Valderrama said water can move faster on pavement.
"In a flood, this could be dangerous for the estuary in Imperial Beach and also the surrounding communities, not just in Tijuana but also in Southern California,” he said.
Magdalena Cerda, director of the Border Campaign for Environmental Justice for the Environmental Health Coalition in National City, said the channelization of the creek must preserve the porousness of the soil, which helps filter pollution and absorbs nutrients and water for surrounding plants. Rocks would achieve that, she said, but concrete would not.
"It has to be (a strategy) where the soil is permeable," Cerda said.
She pointed to a recent $1 billion plan in Los Angeles to restore the Los Angeles River as evidence that paving over rivers is "an obsolete strategy." She thinks turning the Tijuana River and most of Arroyo Alamar into channels will cost the city more money in the future when residents start demanding the restoration of natural habitats.
Valderrama of the Native Plants Society added that the wildlife in Arroyo Alamar is worth protecting.
“It is probably the last big stand of cottonwoods, sycamores and other trees you would normally find in riparian areas, and that are gone in Tijuana.”
Government and industry leaders have said they agree, and that they plan to preserve this small section of the creek to the extent possible. City officials declined to comment for this story, citing upcoming elections. But the president of the National Chamber of Commerce in Tijuana, Gilberto Leyva Camacho, said development doesn’t have to be incompatible with the preservation of Arroyo Alamar.
“We can do both things. We can protect the environment and be modern, with port of entries that are bigger and more dynamic," he said.
Community members are still waiting to have their first advisory committee meeting to negotiate with the government.