WOLA: Advocacy for Human Rights in the Americas

(AP Photo/Gregory Bull, File)

14 Dec 2017 | Publication

WOLA Report: Lessons from San Diego’s Border Wall


The limits to using walls for migration, drug trafficking challenges

Following one of the Trump White House’s first executive orders, U.S. Customs and Border Protection (CBP) commissioned six companies to build eight prototypes for a new U.S.-Mexico border wall. Funded by diverting $20 million away from needed technology upgrades, the prototypes—18 to 30 feet tall and 30 feet long—now rise above a site up against the border, near existing fence southeast of San Diego, California. Most are blank concrete slabs, indicating that the practice of barrier design has advanced little since the Soviets threw up the Berlin Wall 56 years ago.

Border wall prototypes under construction at a CBP site near San Diego, October 21, 2017. (Credit: Mani Albrecht, U.S. Customs and Border Protection Office of Public Affairs Visual Communications Division)

No matter what you think about their aesthetics, though, the choice of where to build the prototypes is also puzzling. U.S. Border Patrol’s San Diego sector is the westernmost of the nine geographic zones into which the agency divides the border with Mexico. Here, the line stretches from the Pacific Ocean 60 miles eastward to a semi-arid, mountainous region called La Rumorosa. The Washington Office on Latin America (WOLA) last paid a visit to San Diego and the Mexican city of Tijuana in May 2017, our third trip to this area since launching a border security and migration program in 2011.

What happens there today shows that under certain conditions, a border barrier contributes to border security. Even more so, the San Diego sector shows just how limited the advantages of fences or walls can be, and how often they’re irrelevant to actual security concerns. The San Diego experience makes clear why wall-building just doesn’t need to be a priority along most of the border right now.

The San Diego sector is one of nine geographic zones into which CBP divides the U.S.-Mexico border. (Map by WOLA).

Fenced-off areas within the San Diego sector are in red.

The border fence’s western edge being built into the Pacific Ocean, November 2011.

San Diego shows what happens when you build a fence in an urban area—and how little difference a fence makes in rural areas.

The San Diego sector already has fencing along 46 of its 60 border miles. The remaining 14 is in very rugged, mountainous terrain, much of it strewn with loose boulders that make transit difficult. The Trump administration’s 2018 CBP budget proposal calls for building 14 miles of new wall in San Diego—but this would not complete the 60 miles. It would replace existing fencing, leaving the hard-to-access unfenced area in its current state.

Topography strongly discourages fence-building in the La Rumorosa region along the eastern edge of the San Diego sector. (Credit: Flickr user Dan Cipolla, Creative Commons BY-NC-ND 2.0 license.)

The 46 miles of current wall cover one of the most densely populated zones of the entire U.S.-Mexico border, the area between the cities of San Diego (metro area population 3.3 million) and Tijuana (1.5 million). Here, building a barrier did make a difference. Between 1966 and 1997, San Diego led all nine U.S.-Mexico border sectors in apprehensions of undocumented migrants. Large groups of migrants would routinely run across the border at once, overwhelming U.S. border guards’ capacities.

Building a fence curtailed this. In 1992, Border Patrol reported apprehending 565,581 migrants in the San Diego sector, with a much larger number likely evading capture. Preliminary fence construction in the mid-1990s brought that number below 200,000 by 1999. By fiscal year 2017, for a variety of reasons—more barriers, more technology and personnel, a changed demographic and socioeconomic reality in Mexico—Border Patrol apprehensions had fallen to 26,086 people, or 95 percent fewer than in 1992, with agents capturing a much larger portion of attempted crossers.

Building a fence reduced illegal crossings in San Diego-Tijuana because of population density. As the Senate Appropriations Committee put it in the explanatory statement for its 2018 budget bill, “physical impedance and denial of access can be the most efficient and effective form of border security in high traffic areas with short vanishing times.” A barrier slows down a would-be border crosser for several minutes. Those several minutes make a great difference in urban areas, where border-crossers can vanish among the population almost immediately after touching U.S. soil.

In rural areas, the advantage disappears. Having no fence may give a crosser a head start of several minutes, but that matters little if he or she must cross miles of open country to reach a population center. (And, in mostly unfenced Texas, to spend several minutes crossing the Rio Grande and fast-flowing irrigation canals). This describes the vast majority of the U.S.-Mexico border, which is rural or wilderness zone like the eastern part of the San Diego sector.

Along the 1,970-mile U.S.-Mexico border, the work of fencing off densely populated areas is practically done. Since the 1990s the federal government has closed off 354 miles of border with hard-to-climb “pedestrian” fencing, and another 300 with fencing that could stop a vehicle. Most of the rest is empty countryside. (The main exception is privately held riverfront land in semi-urban parts of Texas’ Rio Grande Valley sector).

Even in an urban zone like San Diego, the fence is no panacea. Migrants and smugglers often seem little intimidated by it. Border Patrol agents in San Diego must constantly patch up new cuts in the existing fence. San Diego sector federal and state law-enforcement discovers several sophisticated tunnels each year employed by drug traffickers, usually to traffic cannabis. The Pacific Ocean teems with panga boats delivering drugs and people to California’s shores, though their numbers may have declined since 2013.

Patches in the San Diego border fence. (Credit: Adam Isacson)

One might expect most migrants to attempt crossing in the remote 14 miles of the San Diego sector’s border that lack fencing. But this doesn’t happen, according to data collected by the U.S. Government Accountability Office. Between 2013 and 2015, of all illegal entries that Border Patrol detected in the sector—combining border-crossers who were captured, turned back, or got away—93 percent took place “in border zones with at least some pedestrian fencing.” Even during the month of October 2017, at the very site where contractors were building wall prototypes along the existing fence, at least a half-dozen people scaled that fence from the Mexican side and entered the construction site.

San Diego shows the growing importance of migrants in need of protection.

In fact, at least five of those fence-climbers were citizens of Nepal who immediately sought out agents to apply for political asylum. They are part of a growing proportion of what Border Patrol calls “non-impactable aliens”: unaccompanied minors and families and other individuals who are seeking protection in the United States. They are not deterred by increased border security and enforcement measures.

Across the entire border, the share of “non-impactables” detained by Border Patrol shot up from less than two percent of all apprehensions in 2003-2009 to over 33 percent in 2016. In Texas’s Rio Grande Valley sector—which receives the highest number of children, families, and other asylum-seekers—Border Patrol officials told us that the fiscal year 2017 proportion was 47 percent.

These migrants are seeking protection from perceived threats to their lives in their home countries. This is fully legal under international conventions to which the United States subscribes. In most cases, these migrants seek out agents rather than evade detection. Of the 26,086 migrants apprehended by Border Patrol between the San Diego sector’s ports of entry in fiscal year 2017, 4,496—17 percent—were unaccompanied children or families seeking protected status. Another 15,452 people seeking protected status showed up at the San Diego sector’s ports of entry (official border crossings). A wall or fence may inconvenience such migrants, but it does not deter them.

The sector sees fewer violence-fleeing Central American children and families because the journey to California is the longest possible across Mexico from Central America. San Diego was sixth of nine sectors in apprehensions of unaccompanied children, and fourth in apprehensions of family-unit members, in 2017. The numbers of Central Americans have been growing in the sector, though. San Diego is one of only three sectors that did not see a decrease in child and family apprehensions in 2017, a year of reduced overall migration border-wide.

San Diego also receives more asylum-seekers from outside Latin America than most sectors. In interviews on both sides of the border, we heard of recent small groups arriving from India, Bangladesh, China, Ukraine, Romania, and a few African countries. A major phenomenon in the latter half of 2016 and early 2017 was a group of about 20,000 Haitians who had originally fled to Brazil after the 2010 Port-au-Prince earthquake. There, they mostly worked on construction projects related to the 2014 World Cup and 2016 Olympics.

Once the games ended, with no work to be had in Brazil’s depressed economy, the Haitians migrated northward, seeking protected status at the U.S. border. Their smugglers, who charged in excess of US$10,000 for the journey, directed them to Tijuana and Mexicali, border cities across from CBP’s San Diego and El Centro sectors in California. There, they planned to enter under a humanitarian parole policy that allowed them to stay in the United States for up to three years. San Diego sector ports of entry (official border crossings) processed and deemed inadmissible 14,442 Haitians in fiscal years 2016 and 2017. Given the high numbers of Haitians arriving to present themselves at the port of entry, CBP contended that it lacked the capacity to process so many individuals at once. In response, and in coordination with CBP, the Tijuana municipal government, the Mexican National Migration Institute’s (INM) humanitarian branch (Grupo Beta), and local organizations worked out an appointment system for approaching the port of entry. This spread Haitians’ appearances at the port over a period of months, with individual wait times lasting as long as seven weeks.

The appointment system was open to Haitians—nearly all of them—who had been given a temporary transit visa to exit Mexico. (Deporting Haitians presents difficulties given complications in consular notifications and the situation on the ground in the country, so the INM provides them with a temporary visa to give them time to leave the country.)

This was not an ideal solution, but it at least imposed some order on the process for processing Haitians. San Diego-based migrant-rights activists called it “the least bad choice.” In Tijuana, migrant shelters, churches, and civic groups banded together to provide temporary food and shelter. As a result few, if any, Haitians saw a need to go east and attempt a crossing in California’s unfenced desert areas.

In this Sept. 2, 2016 photo, Haitian migrants line up as they wait to enter the U.S. border crossing, in Tijuana, Mexico. (AP Photo/Gregory Bull)

However, this appointment system only applied to Haitians. Asylum-seeking Central Americans and others who did not have this visa, as well as Mexican citizens in need of protection, were not able to get appointments with U.S. authorities.

Indeed, parallel to the complications in processing Haitians, in 2016 organizations and lawyers representing asylum seekers began denouncing an alarming increase in illegal or improper “turn-backs” of protection-seeking aliens at ports of entry. This was taking place all along the border, but particularly at the San Ysidro port of entry. The situation worsened around the time of Donald Trump’s election and after he took office.

According to numerous reports and a lawsuit that several groups filed in California, the post-election period saw a jump in instances of CBP officers falsely telling asylum-seekers “we are not granting asylum,” claiming that the new Trump administration had changed asylum rules (it hasn’t), or even “threatening or intimidating” them. Under U.S. and international law, if someone requests asylum at a U.S. port of entry, CBP officers need to refer that person to a U.S. Citizenship and Immigration Services asylum officer for a credible fear interview. It is not under CBP’s authorities to reject that person.

In September 2016, the Obama administration announced that it would resume deportations of Haitians back to Haiti, and that Haitians arriving at the border without a visa would be put into removal proceedings. (This policy halted in October 2017 after Hurricane Matthew hit Haiti, but resumed in November.) This decision left thousands of Haitians stranded on the Mexican side of the border.

In response to this situation, Mexican authorities provided many Haitians with a humanitarian visa, a one-year, renewable permission to remain in the country. After three renewals (four years), a Mexican migration official explained to us, it is possible for an individual to receive permanent permission to remain in Mexico, though the criteria are not clear.

The Tijuana community made a great effort to receive the over 2,600 stranded Haitians; another 900 were residing in Mexicali. By the time we visited Tijuana in May 2017, the last shelter occupants had moved into more permanent housing, although many continue to live in precarious housing.  Haitians have found paying work in the city’s relatively low-unemployment economy and in the informal sector, although many face employment obstacles because they lack an identification document so that a company can meet its fiscal requirements before the Mexican government.

Local leaders involved in the Haitians’ integration into Tijuana and Mexicali attribute their ability to adapt to this migration’s finite nature. There were a few thousand individuals who had undergone the long journey from Brazil, with little probability that they would be followed by tens of thousands more compatriots. (The potential flow of Central Americans, by contrast, is more open-ended, and except for shelters, the Tijuana community tends to be far less welcoming.)

But the Haitians’ arrangement is a stopgap solution. Although some Haitians are settling in Tijuana and a few other border cities, the Mexican government offered them visas in response to a decision by U.S. authorities, much like what happened after January 2017 to thousands of Cubans who were also left stranded when the Obama administration ended the “wet foot/dry foot” policy.

The experience showed that U.S. ports of entry, along with Mexican authorities, also need to develop clearer procedures and protocols to address sudden flows of migrants seeking protection at the border. Throwing together an ad hoc appointment system for U.S. processing was hardly a permanent fix for a challenge that might recur.

The arrival of the 20,000 Haitians, as well as that of the thousands of Central American and other countries’ citizens petitioning for protection in San Diego each year, also show the irrelevance of the sector’s border wall. The barrier does not affect the calculations of people who seek a legal status that will allow them to live and work in safety.

San Diego shows the need to focus on ports of entry.

Though “turn-backs” are happening less often than a year ago, and lack of space to receive asylum seekers can no longer serve as a pretext for not receiving them, San Diego’s ports of entry remain beleaguered. Even though it is one of the most fenced-off Border Patrol sectors, 2016 seizure data indicate that, of all nine sectors, San Diego is the number one destination for heroin, methamphetamine, cocaine, and possibly fentanyl being transshipped from Mexico to the United States. And authorities in the sector seize by far the largest amount of them at ports of entry.

These drugs go to San Diego because Mexico’s Sinaloa and Jalisco cartels oversee production and transshipment that happens overwhelmingly in Mexico’s Pacific Coast states. They find the border fence to be no deterrent.

Of illegal drugs seized throughout the U.S.-Mexico border, all except cannabis travel mostly through ports of entry—not the areas between them where Border Patrol operates and where walls exist or might be built. “The most common method employed by these TCOs [transnational criminal organizations] involves transporting illicit drugs through U.S. ports of entry (POEs) in passenger vehicles with concealed compartments or commingled with legitimate goods on tractor trailers,” notes the Drug Enforcement Administration’s latest National Drug Threat Assessment. The DEA report adds, “According to CBP, most heroin smuggled across the border is transported in small, multi-kilogram loads, in privately owned vehicles, usually through California”—the San Diego sector.

This mid-2017 graphic from the San Diego Union-Tribune, using data the newspaper obtained from CBP in the sector, shows the overwhelming majority of cocaine, methamphetamine, and heroin seizures occurring at San Diego’s ports of entry.

This series of small column graphs shows San Diego seizures of each drug between the ports of entry where Border Patrol operates (on top), and at the ports of entry themselves (on the bottom). Note the very different scales of these graphs’ y-axes: in nearly all cases, the amounts seized at the ports of entry are a multiple of what authorities find in the spaces between them.

Why do traffickers use San Diego’s ports of entry, instead of the rural or unfenced parts of the sector? Because their products are very small in volume and hard to detect. Traffickers usually put small amounts—several kilograms or less—in vehicle compartments or cargo containers, or even on or inside the bodies of pedestrians, entering the United States through the official crossings.

Methamphetamine seized from the spare tire of a Honda Civic at the San Diego sector’s San Ysidro port of entry, November 2017. (Credit: CBP)

(The one exception is cannabis, which is much bulkier and heavier than the other substances. DEA’s threat assessment notes, “Marijuana is the only drug covered in this assessment that is predominately [sic.] smuggled between, instead of through, the ports of entry.” Perhaps because of its fence, San Diego is not the number-one border sector for cannabis seizures. In 2016 it was a distant third, with most uncharacteristically occurring at ports of entry.)

Traffickers using the ports of entry face good odds. The DEA estimated that Mexican criminal organizations produced 81 metric tons of heroin in 2016, nearly all of it for the U.S. market. Yet heroin seizures across the U.S.-Mexico border totaled 1.7 metric tons that year.

These 81 tons, enough to fit into three standard shipping containers, are scattered in small amounts throughout the border (primarily San Diego) 365 days per year. Detection is even harder for fentanyl, a super-potent synthetic opioid principally manufactured in China and transshipped through the mail or via Mexico. A dose of fentanyl too small to cover Abraham Lincoln’s head on a penny is lethal; the Washington Post estimated that a 141-pound seizure in Queens, New York earlier this year was large enough to overdose 32 million users.

This poses a giant challenge to officials stationed at the ports of entry. These are not green uniform-wearing Border Patrol agents, who work between the ports. They are blue-uniformed CBP officers, managed by the agency’s Office of Field Operations, carrying out customs duties at land crossings, airports, and maritime ports.

While detecting smuggling of people and contraband, CBP officers at the ports of entry must also avoid impeding legitimate commerce and travel. This is a pressing demand, as vehicles entering the United States at major ports of entry routinely must wait in line for an hour or two. This happens often at the San Ysidro port between San Diego and Tijuana, through which well over 35,000 passenger vehicles and buses pass northward every day.

Long wait at the San Ysidro port of entry. (Credit: Josh Denmark, U.S. Customs and Border Protection)

Though San Ysidro has been getting a major overhaul, a local journalist who crosses often told us that wait times are worsening. And unlike San Ysidro, many of CBP’s land ports of entry border-wide are decades old and dilapidated, with about US$5 billion in unmet infrastructure needs. And meanwhile, even with more modern facilities, CBP’s Office of Field Operations lacks people to operate the ports of entry. With 23,079 officers manning all border crossings, airports, and maritime ports, the agency is well below hiring targets; its “workload staffing model” finds a shortfall of 2,107 officers.

With insufficient personnel, the ports of entry end up like a supermarket without enough cashiers, with customers lining up to the back of the store. This works to the advantage of traffickers concealing small amounts of very potent drugs as they enter the San Diego sector. It remains perplexing, then, that the Trump administration’s 2018 budget request for CBP includes US$1.6 billion for new wall construction, but no funding increases for border ports of entry.

Construction was ongoing at the San Ysidro port of entry in May. (Credit: Adam Isacson)

The criminal syndicates moving their product through the ports, meanwhile, are locked in a violent and worsening competition on the Mexican side of the border. Since about 2011, after the Sinaloa cartel wrested control of trafficking routes from the nearly defunct Arellano Felix Organization, Tijuana enjoyed several years of calm. Homicide and violent crime rates plummeted, businesses opened up, and municipal police underwent some promising reforms.

But since 2015, and especially after the third arrest and the extradition of Sinaloa leader Joaquín “Chapo” Guzmán, this “Pax Mafiosa” has ended. A powerful upstart organization dominating an increasing share of the heroin trade, the Jalisco New Generation cartel, has challenged Sinaloa’s monopoly on criminal activity in Tijuana. As a result, Tijuana is mirroring the violent crime spiral from which all of Mexico is currently suffering. For 2017, the city is on track to break its annual homicide record.

Most of the killing has been confined to the city’s poorest neighborhoods: the colonias where cartel-tied gangs battle for territory in which to sell drugs and extort businesses. For now, Tijuana’s downtown and tourist zones haven’t been hit hard by the crime wave, but civic and business leaders worry that it won’t be long. A June 2017 poll found 92 percent of the city’s residents feeling unsafe.

On the California side, however, violent crime levels remain low; most jurisdictions are below the national average. As elsewhere along the border, including regions without fencing, Mexico’s organized crime violence rarely “spills over” into the United States.


On the U.S. side, with the exception of drug transshipment at the ports of entry, the San Diego sector of the border is quiet. In fiscal year 2017, each of the Border Patrol agents stationed there (there were 2,325 at the end of 2016) apprehended an average of only about 11 migrants, or one every 32 ½ days—and as noted, 17 percent of these were “non-impactable” children and families.

In part, San Diego is quiet because it has a border fence at its most densely populated points. The quiet also makes plain that San Diego needs no fence or wall construction in its rural zones, where some in the current U.S. administration would waste resources on a coast-to-coast wall.

Still, San Diego is not a model of perfect border security. It suffers from personnel and infrastructure needs at ports of entry. Several agencies need resources and training to process and quickly transfer requests for asylum and other protections. Law enforcement needs more capacity to detect and dismantle organized-crime networks. They also need upgrades to communications and detection technologies, and safeguards to ensure that their use does not violate civil liberties.

The big, unattractive border-wall prototypes being built on a lot in the San Diego sector are irrelevant to these needs. Yet to address these needs would be far less expensive than building out the wall, which at the rate of the 2018 CBP budget request would come out to US$21.2 million per mile.

The solutions that the San Diego border sector needs today don’t call for large-scale, pharaonic construction projects. After 20 years of rapidly increased funding and rapidly declining migration, small, smart adjustments are all that managing the border requires.