Cleaning up the Tijuana River estuary by building homes for the poor

While working in a Wildcoast event in 2009, Steve Wright was dismayed by the thousands of automobile tires he found cluttering the otherwise protected wetlands in the southwestern corner of San Diego County. He traced the tires back to their source and discovered that they were coming out of the barrancas of Tijuana, where maquiladora workers lead a marginalized existence. The tires are trash that never made it to the municipal landfill, it turned out, simply because the city’s trash trucks can’t negotiate the barrancas’ precarious dirt roads.

The barranca, a common geological feature of the Baja California peninsula, is an especially steep sort of canyon carved out by an arroyo. (Arroyos, in turn, are seasonal streams, dry in the summer and effusive in the winter, which is why their barrancas are so precipitous.) How some of the poorest people from the most rural parts of Mexico came to be living in these barrancas is still an politically charged question … locally the inhabitants are called paracaidistas (parachutists) because they seem to have dropped from the sky … their critics north of the border refer to them as squatters because they’re living on unsaleable land that they didn’t pay for … and somehow or another they began to populate the barrancas when the maquiladora industry boomed during the 1980s.

In the beginning, no one took much notice of the people in the barrancas, at least not at any official level. They were quite literally off the map. No roads, no schools, no electricity, no sewage system. Just a bit of rural Mexico lost in the folds of a growing metropolis. Over time, these informal settlements have acquired a few schools and some electrification, but their rapid growth and the harsh terrain have prevented them from developing modern urban infrastructure.

When Wright traced his tires back to their source, he found himself in the barranca known as Cañón Los Laureles, one of the original maquiladora settlements. He also found that not all of the tires in Tijuana cross the border to clutter up the estuary – some of them stay in the barrancas as homemade retaining walls. And that gave him an idea. If some discarded tires were being used architecturally, why not use all of them that way?

There are, according to Wright’s research, some two billion discarded tires in Mexico and a third of a billion more in the U.S. Each of these tires currently represents a potential expense: San Diego pays fifteen dollars apiece to move them from the Tijuana River Estuarine Reserve to the public dump while, in Mexico, it costs a little less than a dollar apiece to have Cemex, the concrete monopoly, recycle them. Wright likes to point out the wastefulness of the current approach. “That’s tax money they’re spending to put those tires into a San Diego landfill. With the same fifteen bucks they spend for one tire, we could be putting thirty tires into a family’s home instead.”

Interest in recycling these tires developed quickly, crystallizing in 4 Walls International, a §501(c)(3) non-profit organization composed of people from both sides of the border. The group is dedicated to the construction of housing that is both ecologically and economically sustainable. Anecdotal evidence from other parts of the world indicated that waste tires are easy to build with and that their structures resist earthquakes, hurricanes, and erosion, so 4 Walls’ first project was to build a proof-of-concept for the material’s efficacy and structural integrity. They put up an agricultural outbuilding in Temecula, California, in 2009.

The following year 4 Walls joined forces with Michael Reynolds’s organization, Earthship Biotecture, to build an alternative mansion in Todos Santos, Baja California Sur. The size of this project allowed them to explore a wide range of techniques for building self-sufficiency into their homes in terms of energy, water, sanitation, heating and cooling, and gardening. “It’s very important that our homes supply the occupants’ needs as much as possible,” explains Miguel Mayagoitia, 4 Walls’ staff architect, “and not just for ecological reasons. The people we build for earn so little money that they can’t afford what food, water, and electricity cost these days. The poorest people in Tijuana pay more for their water than anyone else because it has to be trucked into the barrancas.”

Mayagoitia developed an interest in ecologically sustainable housing when he was still at university. He joined 4 Walls during the Todos Santos project, contributing a broad repertoire of alternative construction materials (including rammed-earth bags, baled straw, papercrete, ferrocement, and walls made out of discarded bottles) to the tires recovered from the Tijuana River. As he puts it, “I studied to be an architect but I’m working as a trashitect.” He also includes biointensive gardens in his designs in order to provide food for the occupants.

What started as simple remediation – the repurposing of post-consumer waste as building materials – evolved into a comprehensive solution to the problems of the Tijuana River watershed wherein each home takes a dynamic role in sustaining the lives of its owners, controlling erosion, stopping pollution at its source, and generating employment. Local residents can be employed to build these homes because 4 Walls construction techniques are easily learned. Once built, these homes also create recycling jobs within their neighborhoods.

With the elements of their holistic design tested and proven, it was time to bring all this back to Cañón Los Laureles. In early 2011, 4 Walls constructed the offices of a plant nursery, Vivero Las Hormiguitas, in the Rancho Las Flores section of the canyon as a demonstration of what can be built quickly and cheaply even where there is little or no municipal infrastructure.

The Las Hormiguitas office contains four hundred thirty square feet of finished construction at a cost of only seven thousand dollars. It currently makes use of water collectors and a biointensive garden; a dry toilet will be on line soon. All of this is meant to show the neighbors what can be in store for their families … and to demonstrate to any government official brave enough to visit that an elegant solution is well in hand to what once seemed an insoluble problem.

A typical 4 Walls home in the barrancas is meant to provide comfortably for a family of four. With solar panels and a complete system for generating natural gas and potable water, it offers some eleven hundred square feet of finished construction as well as a biointensive garden all for less than twenty thousand dollars. Its occupants experience a radical change in their standard of living: “they know they’re preventing erosion and pollution on a daily basis,” says Mayagoitia, “which creates a sense of guardianship in the land, a sense of community that goes well beyond being just a place to sleep between shifts at the factory. These homes reduce ‘survival stress’ because they provide daily needs that previously had to be carried in. That creates time for the inhabitants to interact, to learn, to teach, to grow as human beings.”

Wright contrasts 4 Walls’ approach with the defensive actions currently being pursued in San Diego County. He points to Wildcoast’s angry complaints that Imperial Beach is closed to bathers more than half of each year because of sewage contamination and that San Diego spends far too much money in cleaning the estuary. As the population in the barrancas increases, San Diego responds by building bigger and bigger waste-treatment plants north of the border: the newest one came to almost three hundred million dollars after all its cost-overruns were paid. “Remediation is not the answer here,” says Wright, “because it only creates a self-perpetuating waste-treatment industry.”

Cañón Los Laureles, home to about a hundred thousand people in the northwestern corner of Tijuana, has become the lightning rod for ecological activists in San Diego. It is, after all, the most visible source of pollution in the Tijuana River Estuary. But it is only one of many canyons that make up an enormous watershed and there are many more thousands of maquiladora workers in the other canyons. Thus any hope of removing the current effluent is forlorn just as removing the source of this pollution – a euphemism for the forcible relocation of the residents – would be prohibitively expensive, if not to say inhumane.

Be that as it may, more maquiladora workers are on their way. Government and industry leaders have announced unanimously that the future of Tijuana is in building high-tech factories rather than in reviving daytripper tourism. And, while these leaders don’t intend to drop the new workers into the barrancas (they’re building out the arid southern periphery of Tijuana to receive a million inhabitants instead), very few provisions have been made to accommodate the additional strain on municipal resources. More water will be needed from the Colorado River, which has been on emergency allocations for more than a decade. More electricity will be drawn from the nonrenewable transnational grid. More natural gas will have to be imported from California. More raw sewage will need to be treated. And more ominous still is Nueva Tijuana’s location within the watershed: downstream and downwind of it lie Cañón Los Laureles and Imperial Beach.

It was with a sense of urgency, then, that 4 Walls presented their program to the San Diego Association of Governments, the supragovernmental agency for the binational area that hopes to coordinate all the local governments between Oceanside and Rosarito. SANDAG gave 4 Walls a blasé reception. “Only about half the committee was even paying attention,” reports a journalist who was covering the meeting for San Diego News Room, “the others were chatting and telling each other jokes. The committee received the presentation ‘as information’, meaning they didn’t intend to take any action on it. Only one committee member offered a public comment and that was to say that 4 Walls would never be able to get a building permit from the city of Tijuana.”

The two primary goals of 4 Walls are to clean up the Tijuana River watershed and to promote truly sustainable building practices throughout the world. Wright talks about creating a “pride of place” among the inhabitants in the barrancas that will prevent any more refuse from entering the wetlands. Mayagoitia talks about the day when they release detailed technical plans to the Internet as open-source documents. Were it not for the bureaucratic indifference, SANDAG could be their most effective partner in achieving their first goal. They have also been developing relationships with non-governmental organizations on both sides of the border that promise, over time, to achieve both goals.

As a result of the Las Hormiguitas build, 4 Walls enjoys close ties with many of the residents in Los Laureles, now potential customers. The organization maintains alliances with Tijuana Calidad de Vida and Reacciona Tijuana, the two most prominent civic-action groups in the city, and hopes to collaborate on housing projects soon. “The only thing that’s holding us back is funding” said a director of Calidad de Vida. Wright and Mayagoitia are also members of the academic task force charged with developing a curriculum for training “green” building tradesmen as part of a million-dollar joint project of the University of Colorado and the Universidad Iberoamericana. Many of the first graduates of this curriculum will be working within the Tijuana River watershed.