Customs and Border Protection (CBP) discovered 40 tunnels from 2017 to 2021, according to data obtained through a Cato Institute Freedom of Information Act (FOIA) request. CBP discovered these tunnels as former President Trump extended his 30-foot wall across hundreds of miles along the border. The former president was warned about the potential for tunnels but insisted that his wall would have anti-tunnel “technology.”

The annual figures reveal an interesting jump in tunnel discovery in 2020. As President Trump frantically built out over 300 miles of his border wall in 2020, the agency discovered nearly one new tunnel per month. The 11 tunnels discovered that year were the highest for the period. One of those 2020 tunnels was said to be the “longest ever discovered.” In 2022, one tunnel was found in “one of the most fortified stretches of the border.”

I wrote about tunnels in “Why the Wall Won’t Work.”

If not over or through, some crossers may opt to go under. Tunnels are typically used more for drug smuggling, but they still create a significant vulnerability in any kind of physical barrier. From 2007 to 2010, Border Patrol found more than 1 tunnel every month. “For every tunnel we find, we feel they’re building another one somewhere,” Kevin Hecht, a Border Patrol tunnel expert, told The New York Times last year. A wall would likely increase the rewards for successful tunneling as other modes of transit grow more expensive. Trump is unconcerned, asserting that “tunnel technology” will rule out any such subterfuge. Effective tunnel detection equipment is seen as the Holy Grail of Border Patrol enforcement, but the Homeland Security Department’s Science and Technology Directorate has so far concluded that no current technology for detecting tunnels beneath the border is “suited to Border Patrol agents’ operational needs.”

It’s interesting that the earlier data seem to indicate that the rate of tunnel discovery declined and that the border wall extension in 2020 may have briefly revitalized it.

These latest FOIA data supplement an earlier Cato Institute FOIA showing that the border wall is being breached nearly 11 times every day. The number of breaches reached 4,101 in 2022, the highest number recorded during that period. Breaches are obviously the far more common and easier method of avoiding the border wall, but tunnels serve as conduits for drug smuggling and can move very large numbers of people and goods quickly into cities where they can go undetected.

As I wrote in “The Border Wall Didn’t Work”:

The Trump border wall failed for all the predictable reasons. Immigrants used cheap ladders to climb over it, or they free climb it. They used cheap power tools to cut through it. They cut through small pieces and squeezed through, and they cut through big sections and drove through. In one small section in 2020, they sawed through at least 18 times that Border Patrol knew about in a month. They also made tunnels. Some tunnels were long, including the longest one ever discovered, but some were short enough just to get past the barrier.

The border wall has failed. It’s a wasteful project that cost $15 billion and is still requiring millions of dollars annually in upkeep. Yet the Biden administration is still building further sections of it. This project should end immediately, and the government should return the sections of the wall already constructed to the property owners from whom the land was taken.