How Much Would Trump’s Border Moat Cost?

(Bloomberg Businessweek) -- The Americans who wanted Donald Trump to be president were attracted to an outsider businessman with out-of-the-box thinking. A person who built things. Weird things, like a barber chair on his yacht, 24-karat-gold seat belt buckles on his jet, and Melania Trump.

So this past spring, as he looked for a way to prevent immigrants from coming over the U.S. border with Mexico, the Great Simplifier latched onto an idea that was logical, obvious, and popular with world leaders, albeit eight centuries ago. As New York Times reporters Michael D. Shear and Julie Hirschfeld Davis wrote in their just-published book, Border Wars: Inside Trump’s Assault on Immigration, the president had been sounding out advisers on “fortifying a border wall with a water-filled trench, stocked with snakes or alligators, prompting aides to seek a cost estimate. He wanted the wall electrified, with spikes on top that could pierce human flesh.” Twitter exploded with laughter when this anecdote came out last week, and while others have moved on to cover Ukraine, impeachment, and some sketchy text messages, I decided to dig in and do some more extensive follow-up reporting when other news outlets started publishing what seemed like rather lowball numbers to me.

For context, President Trump actually has a fair amount of moat knowledge, despite spelling it “moot” on Twitter when denying he had ever suggested building one. In 1983 he worked with architect Philip Johnson to design Trump Castle, a never-built 60-story residential complex with six towers, complete with gold-leaf-covered spires, a moat, and a drawbridge. Carefully ranking his adjectives, Johnson said at the time: “Trump is mad and wonderful.”

While we don’t have any government estimates on how much it would cost to build a moat across the entire U.S. border with Mexico, we here at Bloomberg Businessweek ran our own numbers.

The good news is that the majority of the 1,954 miles of the U.S.-Mexico border is river, or as Trump will call it, Free Moat. That leaves only about 700 miles of Paid Moat.

The first expert I approached is the contractor who renovated my house in Hollywood, Dennis Bilden. Though Bilden hasn’t installed a moat, he has installed moat-like structures. “I just finished building three pools,” he told me. “Everything is automated. LED lights. It had a spa inside of it. It has these fountains that come out of the deck that shoot up. There’s like four of them. It’s very cool.” The average cost for a 32-foot-by-14-foot pool is $189,000; if Bilden were to charge Trump an equivalent rate, it would cost more than $22 billion. That’s way beyond the $5.7 billion Trump shut down the government to get for the wall at the beginning of this year. But based on my experience, if Bilden does it, it’s going to be supercool and done on time.

Michael Prestwich, a professor emeritus in medieval history at the U.K.’s Durham University and the author of Armies and Warfare in the Middle Ages: The English Experience, says the best estimate he can offer is based on the digging of the 3,156-foot moat around the Tower of London. “Overall, between 1275 and 1281 the cost of wages alone was £4,150. That excludes cost of materials such as piling,” he said. In today’s money, that’s about $3.5 million. So for 700 miles on the U.S.-Mexico border, that would come to a bit more than $4 billion on labor alone. Add in materials, the LED lights, and those cool fountains, and it might be close to the estimate Bilden gave.

Prestwich didn’t have much information about the alligators, largely because, outside of fairy tales, no one put alligators in moats. “King Henry III had a polar bear, which used to swim in the Thames. He also had an elephant. Neither lasted long. Edward I had some lions, but these were not there to deter attackers—they were more of a tourist attraction, and you had to pay to look at them.” This moat/zoo public-private venture, I believe, is something that Trump would be psyched to make cabinet members investigate.

The Panama Canal might provide a more accurate cost comparison for a modern border moat. James R. Phelps—who has taught courses on homeland security at Nova Southeastern University in Florida, is special assistant to the president of Emirates College of Management & Information Technology in Dubai, and co-wrote a book called Border Security—extrapolated from the size of the Panama Canal, converted the cost to today’s dollars, and got $16.349 billion, not including materials, “if he uses Central American or Mexican labor for the grunt work.” This seems like a politically difficult ask, especially if you call it “grunt work,” but Phelps believes it’s possible.

Phelps, however, says that building the moat isn’t the real cost. “Don’t forget, you have to fill the desert areas with water,” he says. Here, the Tower of London is again instructive. When the Historic Royal Palaces in 2007 looked into filling up the moat for the 2012 Olympics, they put the cost at between £13 million and £18 million. And that was pre-Brexit, when £18 million bought something.

If the U.S.-Mexico moat is 30 yards wide and 10 yards deep, that’s more than 74.7 billion cubic yards of water (about 15 trillion gallons), which would cost $28 billion to $40 billion based on the estimates for the Tower. Phelps estimates the water in an area where it rains far less than London and has no water supply would cost as much as $342 billion. Plus, you’d need to get it there. “Don’t forget the cost of fuel,” Phelps adds. “And the price of water will rise dramatically as soon as somebody says they need the water in bulk for a government moat.” And it’s going to evaporate quickly. The Sierra Club estimates a pool in Texas loses 60 gallons a day, so you’re going to have to add another 20 percent of water to your cost every year.

“Flesh-piercing spikes” would be pretty cheap to affix with epoxy and broken Modelo bottles, but Phelps says electric fencing in the middle of uninhabited areas is far too expensive to even consider. “That’s why they are only used as the innermost barrier fences on strategic weapons manufacturing facilities. It’s easier and cheaper to just seed the border with land mines,” he adds, using a sentence we can only hope Trump doesn’t read.

The good news for Trump is that alligators have been crazy cheap for the last few years. You can score an alligator hatchling for an unbelievable $56. Phelps thinks Trump would need one gator for every 1,000 yards of moat (both Free Moat and Paid Moat), so about 3,500, or $200,000 worth, assuming they’d thrive in an area where there isn’t much to eat. Much like moats need water, alligators need about 300 pounds of food per year. You can score frozen mice for $7 a pound, which puts you at more than $7 million for the first year, not including fees for the alligator feeders. Snakes can be even cheaper than gators: you can get a ball python for $20. However, as you’ll discover if you watch the YouTube video “15 Reasons Ball Pythons Are Awesome Pets,” they aren’t very menacing.

Others have gone through similar analyses and come up with prices ranging from $12.2 billion, plus $1.2 billion in yearly operating costs, to around $30 billion. Based on Businessweek’s high-end estimates for water and construction (not including my contractor’s), throwing in the transportation and cement costs, Trump could build a gator-filled moat for maybe $450 billion. You could find that money simply by eliminating the Environmental Protection Agency, the Department of Energy, the Department of Education, the Treasury, NASA, the Department of Health and Human Services, and the State Department, and then cutting the military budget in half. Toss out the Department of Labor and Dennis can get the hot tub, the LED lights, and the shooting fountains.

To contact the editor responsible for this story: Jillian Goodman at jgoodman74@bloomberg.net

©2019 Bloomberg L.P.