Republican presidential candidate Donald Trump is introduced during a campaign rally in Concord, N.C., Monday, March 7, 2016.

Republican presidential candidate Donald Trump is introduced during a campaign rally in Concord, N.C., Monday, March 7, 2016. Gerry Broom/AP

What It Would Take to Build Trump's Border Wall with Mexico

The presidential candidate is pledging the largest infrastructure project since the U.S. highway system. And it makes no sense at all.

If for no other reason, history will remember the 2016 presidential election for Donald Trump’s campaign promise to build a wall across the entire Mexico–U.S. border. Set aside for a moment the rather vexing question of whether Trump will win the White House. Let’s focus on the pitch that could get him there: Could Trump in fact build a Great Wall of Making America Great Again?

As with so many things in this election, the question beggars belief. Trump is pledging the largest infrastructure project since the U.S. highway system—perhaps the most significant infrastructure project since the Erie Canal—and yet he has shared few details about the wall itself. What little Trump has said, namely that he intends for Mexico to pay for it, is unrealistic, to put it mildly.

Details are beside the point, of course. That’s because Trump can’t build a wall across the entire border. It’s a moon-shot without a rocket. The proposal crumbles at even the slightest scrutiny. No one who can build it would, and no one who would build it can.

“With the highly contested nature of this project, and the fact that many, many people object to it really strongly—do you want to be on the wrong side of that in a way that’s going to stick with you for years?” asks Raphael Sperry, president of Architects/Designers/Planners for Social Responsibility.

Sperry says that his organization will condemn the border wall, should Trump be elected president. His organization may not stand alone: Other professional design associations are bound by ethics that Trump’s proposal appears to plainly violate. As with other controversial border projects, firms that built this wall could be subject to boycotts, blacklists, and lawsuits.

Critics tend to dismiss Trump’s chief policy proposal as bonkers. Engineers have never shied away from projects that seem impossible, but walling off Mexico is something worse: It’s impractical. Reputational risk, ethical conundrums, and environmental liability each pose significant obstacles to building the project. This wall is a wall unto itself.

What kind of project is a massive border wall?

Say that a community decides to build a port. If there’s strong support for a port, then Congress will authorize a study to determine the federal need for or interest in the project. Enter the U.S. Army Corps of Engineers, which works with the local community to study the costs, benefits, and need for civil infrastructure projects. If everything checks out and the Corps decides to take on the project, it issues a chief’s report, which goes up to the Army and from the Army on to Congress.

For most large-scale civil construction projects, and anything involving U.S. waterways, the Corps takes the first look. A 2,000-mile border wall, one that crosses the Colorado River and runs alongside (or through?) the Rio Grande, would fall under its regulatory purview. Whether the Corps would take on the building project is harder to say.

Eugene Pawlik, a spokesperson for the U.S. Army Corps of Engineers, declined to speculate about the border wall specifically. But he did explain that the Corps maintains few projects that could be described as “national.” Even theMississippi River and Tributaries Project, the largest flood-control system in the world, is maintained by the Corps as a series of individual elements: levees, floodways, and so on. Each project is conceptualized, built, and operated as a local concern.

So Corps projects typically start from the bottom up, especially in today’s post-earmark era. Infrastructure projects rarely begin with the executive branch, even if they do receive federal support. Seen through one lens, Trump’s answer to immigration is the supreme evocation of executive authority: The White House will build a wall. The audacity of Trump’s proposal brings to mind the earliest debates about the division of powers, when the Hamiltonian Federalist Party (later the Whigs) sponsored “internal improvements”—best represented by the Erie Canal—in the face of fierce objections from the Jeffersonian Republican Party (later the Democrats). (Today’s debate is not quite of the same calibre.)

In the here and now, a proposal for a wall crossing state lines might be broken up into smaller constituent projects, to be evaluated independently. This process could open up multiple potential points of failure—objections that an 80-foot-tall wall running through or along the Rio Grande violates the National Environmental Policy Act, for example. Or objections that the wall divides divides certain animal populations, violating the Endangered Species Act. Residents of El Paso may object to an 80-foot wall in their back yard.

It would take an act of Congress to clear the many obstacles to building a Great Wall. That’s one way to guarantee the Corps’ involvement. Congress has the power of the purse to authorize the Corps to take action and the appropriation power to fund that action.

“If Congress puts the language into a bill that says, ‘Go forth and execute,’ providing authorization and funding, then certainly, we as the Corps of Engineers would follow what’s in the law,” Pawlik says.

The Corps would not physically build the wall themselves. For most projects, the Corps engages a “prime” contractor, who then hires on other subcontractors. A wall running thousands of miles through hills, deserts, and rivers would take a major campaign, possibly involving multiple primes. Not to just to build the wall, but to support the builders: to build the roads that would enable the builders to reach the border. No small feat.

No one with the can-do will do

There are just a handful of architectural and engineering firms with the organizational capacity to build Trump’s wall. Not the technical know-how—any engineer can design a wall—but rather the experience in management. Marshaling the array of contractors and subcontractors it would take to build a wall across so many different jurisdictions and climate regions would require a fairly elite engineering firm.

None of more than a dozen global architecture and engineering firms I contacted were willing to speak on the record about Trump’s wall. Neither did faculty at the schools of civil engineering for Texas A&M University and the Georgia Institute of Technology. But several sources pointed to codes of ethics that seek to prevent architects, engineers, and planning professionals from doing harm.

The American Institute of Certified Planners, for example, includes in its code of ethics a subsection that reads as strongly at odds with the goal of blocking immigrants from reaching the U.S. through Mexico:

We shall seek social justice by working to expand choice and opportunity for all persons, recognizing a special responsibility to plan for the needs of the disadvantaged and to promote racial and economic integration. We shall urge the alteration of policies, institutions, and decisions that oppose such needs.

(UPDATE 11:00 a.m.: Jim Peters, the ethics officer for the American Planning Association, said that the planning chapters in the affected states—Texas, New Mexico, Arizona, and California—would likely lead on this issue. “Trump can talk all he wants about a wall, but how do you fund a project like that?” he says. “And is that a project that those states and the country at large wants to commit to and believes in?”)

The American Society of Civil Engineers is bound by a code of ethics that is only slightly less pointed. “Engineers should seek opportunities to be of constructive service in civic affairs and work for the advancement of the safety, health and well-being of their communities, and the protection of the environment through the practice of sustainable development,” the code reads.

“The [American Institute of Architects] does not dictate what clients members can accept,” writes Cornelius DuBois, chair of the AIA national ethics committee, in an email. “However, there are a number of points in the Code of Ethics that should encourage [members] to think of the ethical challenges of accepting a commission or project. And it is by no means certain that an architect would even be involved in designing such a wall, which is primarily an engineering project.”

(Global design firms employ both architects and engineers. On Trump’s wall, DuBois is right: Architects design structures that include enclosures, so Trump’s wall would likely be designed by an engineer, unless it involved chambers for trials or confinement. The AIA is currently considering a petition to prohibit architects from designing prisons with execution chambers or spaces designed for degrading treatment of prisoners, such as solitary-confinement cells.)

To be sure, design firms may not give a flip about the ethical codes at any of these professional organizations. They may never be pushed to make that call. Neither the ASCE nor the AICP has any official position on Trump’s proposal; the code of ethics for the National Society of Professional Engineers doesn’t have anything to say at all about taking on dubious or divisive projects. Truly, it’s hard to imagine an association suggesting that an engineer could lose membership or licensure for taking on a project supported by the White House. Then again, the president has never called for sealing off the border.

There is a greater occupational risk to joining such a controversial project than professional tut-tutting, though. Veolia, a French multinational infrastructure corporation, paid through the nose for its operations in illegal Israeli settlements in Palestine after it was targeted by the international Boycott, Divestment, and Sanctions movement. “This has earned us boycott threats and lost us important contracts,” one Veolia executive lamented to the Agence France-Presse in 2010.

Then there is the upfront promise of non-payment. Trump has told his supporters that Mexico, not U.S. taxpayers, will pay for the wall to be erected along the border. Mexican President Enrique Peña Nieto has declined Trump’s offer, comparing Trump to Mussolini and Hitler for his trouble.

"For somebody to take on a project where your client says, 'Oh yeah, this other third party is going to pay for it,' when clearly they have no intention of paying for it, and there's many people in that organization who have made public statements that they're not going to pay?” Sperry says. “In my profession, I have yet to meet someone who actively wants a project where their client's saying they're not going to pay them.”

The price tag for a wall across the border would be yuuge

Building Trump’s wall across the Mexican border might require one-tenth of the cement the U.S. produces in an entire year. Maybe more. Maybe all of it.

Since the height of the Great Wall of Making America Great Again keeps rising, it’s hard to give anything better than a stab in the dark at what it would cost to build, for whoever ends up stuck with the tab. One Daily Kos contributor outlined a plausible-sounding guesstimate regarding the sheer amount of cement it would take to wall off 2,000 miles of mostly natural border.

Bill Palmer Jr., the editor of Concrete Construction, offers that a concrete wall running 80 feet high (including 30 feet below grade), 1 foot thick, and 2,000 miles long would require 31 million cubic yards of cement. “If we made it higher-strength concrete, go to 700 pounds per yard, that’s 21.7 billion pounds of Portland cement, or about 10 percent of U.S. annual consumption,” he writes in an email. Cement is just one ingredient in concrete, and concrete is just one component of a wall-building project.

“On a project like this, they would be making their own concrete, so the price would go down,” Palmer writes, “but getting materials, equipment, and people to the job site and building this as a government project ([at] prevailing wages) would be very expensive.” (Emphasis his.)

Those costs would not go away if the U.S., under Trump, opts to build a mere fence, not a true wall. Neither would the lawsuits, presumably all of which would need to be settled—along with right-of-way acquisition—before engineers could break ground. There is no way that the cost of building a border half the length of the Great Wall of China doesn’t reach astronomical heights.

Over a long enough timeline, perhaps these staggering costs would not represent a harrowing national burden. The wall-building scheme could span years, maybe generations. Rome wasn’t built in a day; America can’t be made great again overnight. That other Great Wall took centuries!

Presumably, though, the political will for building a wall blocking the border with our strong ally and trade partner—the sheer amount of, let’s call it “enthusiasm,” required to sustain such an effort—will run out sooner rather than later.

Could Trump supporters build his wall for him?

Now, I’m sure that Trump would say that he knows engineers, really great engineers, they do terrific work, and they are asking him, “Donald, how are we going to build this wall together?” And he tells them, “We are going to build a great wall and we are going to get Mexico to pay for it.”

Maybe a Trump supporter runs a design firm with the level of experience necessary to plausibly bid as a contractor on a request from the U.S. Army Corps of Engineers. Maybe this firm does not mind the risk of censure from professional groups that could come with the commission. Maybe this firm does not fear the almost-certain boycotts that would come with the job. Maybe this firm isn’t bothered by the prospect of never even being paid for the work.

For mainstream designers, however, the sanction of the International Court of Justice is something to be avoided. Most engineers shun notoriety, much less aggressively court it. Designers of all political persuasions are bound to pass on projects that draw casual references to fascism from sitting heads of state. The judgment of history is a big ask for pro-bono work.

Trump’s quixotic quest comes at a time, too, when designers are reevaluating their role in society. It is no small thing the AIA is mulling a prohibition on designing inhumane prisons: Without a licensed architect to stamp the drawing, that prison pretty much doesn’t get built. The design industry may yet have an opportunity to show its mettle.

“Anybody retrospectively who looked at the Berlin Wall would say, ‘That was a bad project,’” Sperry says. “If you were the engineer who designed part of it, would you ever be proud of that project? Only if you were a crazy ideologue of the Soviet system. Which was a horrible system.”