TIJUANA – The unpaved road we’re driving on is still thick with mud. It’s been 24 hours since the rain stopped, and the earth is scarred by freshly carved gullies. Cars are coated in mud up to their windows. Nearby, a mangy brown mutt is timidly negotiating a six-foot-deep cement ditch that’s lined with graffiti and is still wet with sewage-tainted rainwater.

The small dog stops, assessing the scene. In front, the water flows faster. A hose gurgles to life, and brings down a torrent of water from a home above. The smell of laundry detergent hangs in the air, a sickly sweet smell wafting through warm afternoon breeze. The dog turns back.

This is Tijuana, post-rainfall. Neighborhoods such as this are directly connected to public health in San Diego. They’re the sources of sewage that close southern San Diego’s beaches. We are just a few miles from the wide, tourist-laden streets of Avenida Revolucion, where roads are paved and police are plentiful. Here, in a neglected section of a growing city, a rainfall spells disaster. Here, an inch of rain cuts roads in half.

The water swallows the soft soil that supports unsteady homes and spits it out on the other side of the border. Agua negra, the locals call it. Black water.

Down the street, a woman wearing an apron smiles at us. She waits for our van to pass, then walks out into the street – a simple, rugged path made of dirt and stones. She’s lugging a green bucket with a Quaker State logo on the side. Suds froth at the rim.

She flings soapy water from the bucket, once, then again. It flops to the ground and soaks in – two semi-circles of suds, two upside-down smiles on a muddy street in the Tijuana neighborhood called Divina Providencia – Divine Providence.

It is Wednesday afternoon, and nine journalists and environmentalists sit in our van, touring Tijuana’s colonias, the canyon-lined neighborhoods where thousands of hopeful workers from Mexico and other parts of Latin America flock in search of better lives. Some jump the border into the United States. Others take factory jobs that can pay $8 daily. The migratory phenomenon – spurred by globalization – creates serious public health issues on both sides of the border.

Disease, pollution and uncontrolled sewage runoff. All are problems that have plagued both sides of the border for decades. On the Mexican side, they contribute to an infant mortality rate triple that of the United States. On the Californian side, Tijuana’s rogue sewage is so serious that the San Diego City Council has declared it a continual emergency since 1993 – though the problem has outpaced solutions.

Like the woman who dumped her suds in the street, many in Divina Providencia lack basic infrastructure: plumbing, clean water, electricity. Exactly how many? No one is sure. Estimates range from 20 percent to 50 percent. Most are illegal squatters. They don’t pay property taxes, so the city’s census doesn’t count them.

At the front of our van, the driver speaks up.

“All these people are invisible to decision makers,” Oscar Romo, our tour guide, says after we pass the woman. “They don’t exist.”

On the American Side

Sediment is thick in the murky river water below us, swirling like creamer in coffee. It’s early morning, and we’ve just started our tour on the American side of the border, crossing the Tijuana River, heading toward the canyons that link the border region’s public health problems. A day ago, the curvy road was impassable. Today, lane-wide puddles are left as reminders.

Romo, 57, is an engineer with two decades of experience in cross-border environmental issues. The soft-spoken Mexico native has spent the last three years working at the Tijuana River National Estuarine Research Reserve. He coordinates its Coastal Training Program, a federally sponsored effort to educate decision makers – the very people he says have ignored the problem.

From here, we can see into Mexico and glimpse the canyon walls where thousands of emigrants – those whom Romo calls invisible – are putting up homes on top of the soft soil. With each new makeshift house, more vegetation is ripped from the earth. And with each winter rainfall, the resulting erosion sends the creamy runoff – laced with toxins, garbage and human feces – to the Tijuana Estuary, a slowly dying 2,500-acre salt marsh in southern San Diego. It’s home to five endangered and threatened bird species and is a key migratory stop for an estimated 370 more.

In other words, Tijuana’s canyons are washing into the United States. Romo estimates nearly 10 percent of the reserve’s salt marsh and mudflats have disappeared in the last four years, filled in by sediment from the colonias. California State Park officials acknowledge the damage to the area they manage, but say it’s taken a century. Silt and sediment from Tijuana’s canyons has buried shellfish, leaving behind areas where birds won’t nest.

The damage is apparent in a satellite view Romo shows us. The estuary’s once-green southwest corner looks like it has been scrubbed by an eraser. In some places, nearly 10 feet of sediment has accumulated. He estimates cleaning it up on the American side would cost $80 million. Simple steps to prevent it on the Mexican side, he says, would cost much less.

We stop at Goat Canyon, a mile inland from the Pacific. Hummingbirds flit through the salty breeze. We walk to the lip of a giant spillway that catches sediment flowing from Mexico. From here, we can see a brown plume of runoff entering the ocean and curving north toward Imperial Beach, where swimming was prohibited 83 days last year because of the sewage.

Sediment coats the wide cement basin in front of us. On Feb. 27, it was clean. Two days later, after less than an inch of rain, Romo estimates it’s nearly a quarter-full.

The $8 million structure can hold 55,000 cubic yards of sediment. Imagine 11 million gallons of milk.

In the two years since it was built, the basin has caught 22 million gallons of sediment. It’s been so full another 22 million passed into the estuary.

“I call them the floor mat,” Romo says. “We use them to control pollution, but they’re not controlling pollution or trash. They’re just storing it.”

Metal poles jutting up from the ground have caught shoes, shirts, detergent bottles, children’s toys. Last year, 6,000 tires were pulled out. From here, we can see across the border fence, past the criss-crossing trails that line the chaparral-covered mountains. Cars are whizzing south through Tijuana. We’ll soon join the rush of traffic.

“You need to see the conditions there,” Romo says.

On the Mexican Side

Smoke from burning plants hangs in the air. People are standing at bus stops, waiting. We’re jostling across a paved road on the Mexican side of the border, heading to Tijuana’s canyons, to the colonias.

We pass uniformed schoolgirls, whose polished black shoes are turning brown with mud. Two toddlers, latched on to their mother’s hands, stomp mud from their shoes as they trade side roads for sidewalks.

We leave the clogged streets behind and bounce down into Los Laureles Canyon, which feeds the giant sediment basin we’d seen an hour earlier.

Men driving backhoes are patching the roads when we enter a neighborhood called San Bernardo. Homes here are built from discarded garage doors and plywood. Romo estimates some 400 families live in them, one of the canyon’s few legal settlements.

They came in 2004 from the Alamar River, east of here, driven out by the risks of flooding. Romo says many earn $70 each week at nearby South Korean maquiladoras and pay $200 monthly for their mortgages.

“Three years ago this was a ranch,” Romo says. “It was pristine. It was beautiful. [Now] it’s completely gone. Nothing left.”

We hop out of the van, and survey the land. This is where Romo’s work with the estuary’s Coastal Training Program is put into practice. He says his role is that of facilitator, helping people on both sides of the border solve cross-border problems. San Bernardo residents don’t know they’re polluting, he says, though he and others are helping educate them. Residents are slowly learning – and getting worried.

“They’re just concerned that their families are being exposed to wastewater, to lots of pollutants,” he says. “Their understanding of environmental issues is greater. But it’s a difficult task to educate a whole canyon.”

Romo kicks at the soft silt on the ground. This is what’s slowly killing the estuary, he says. It’s evidenced a few hundred feet away, where a home is perched atop a concrete slab. The earth beneath it is giving way. Soon, a heavy rainfall will claim another home.

The road deteriorates the further we go. The rain cut gullies a foot deep. A half-dozen people – men, women, and children – are working in the street, filling the fresh gaps with tires, rocks, mud, anything. Their brows are wet with sweat.

“This is interesting,” Romo says, pointing to the horizon. “From here, you can see downtown San Diego, the Marriott.”

The connection between the colonias and the high rises in the distance, he says, is obvious.

Editor’s Note: The original version of this story wrongly stated that the Tijuana workers discussed were typically earning $70 a month. They earn $70 a week.

Please contact Rob Davis directly at rob.davis@voiceofsandiego.org with your thoughts, ideas, personal stories or tips. Or send a letter to the editor here.

Leave a comment

We expect all commenters to be constructive and civil. We reserve the right to delete comments without explanation. You are welcome to flag comments to us. You are welcome to submit an opinion piece for our editors to review.

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.