Investigators have uncovered 88 in Nogales, Ariz., alone since the 1990s, accounting for more than half of the 153 tunnels found on the border.
“Tunnels are unique because it’s almost a foolproof way of getting narcotics into the United States,” said Kevin Kelly, assistant special agent in charge of the Homeland Security investigations directorate in Nogales.
He said Nogales has several things that make it attractive for tunnels: Houses are close together, ownership is often unclear and two large storm drains flow south under the city into Sonora, Mexico.
Besides making tunneling easier, the short distance between Sonora and Nogales also provides a wealth of potential drop sites for smuggled goods, Kelly said.
Investigators said tunnels vary in size and sophistication — from some that only allow for one man to crawl through, to others with complete lighting and ventilation.
“It’s a cat-and-mouse game to investigate a tunnel,” Kelly said.
The Department of Homeland Security said that since 1990, officials have found 42 tunnels into San Diego, 12 to Calexico, Calif., and two to Tierra Del Sol, Calif. In Arizona in that time, they have discovered three in San Luis, 88 in Nogales, one in Naco and three in Douglas.
“In Arizona, there’s already an existing infrastructure for smugglers to utilize,” said Tim Durst, assistant special agent in charge of Homeland Security Investigations for Immigration and Customs Enforcement in San Diego.
Durst also told the Senate Caucus on International Narcotics Control on Wednesday that climate makes it easier to build tunnels in Arizona and Southern California.
“I think Arizona and California just have more appropriate conditions for drug smugglers to take advantage of,” he said at the hearing on prosecution of tunnel crimes along the Southwest border.
James Dinkins, executive associate director of Homeland Security Investigations, said the increased number and sophistication of tunnels is a direct response to law enforcement efforts.
“We’re literally forcing them to go underground,” Dinkins said.
Sen. Dianne Feinstein, D-Calif., co-chair of the caucus, said she has visited numerous tunnels, noting the scale and size as well as their depth — one was more than nine stories below ground, complete with ventilation and concrete floors.
“The only reason they build a tunnel is to avoid authorities,” Feinstein said. “It’s a real way of serious criminal penetration into the United States.”
Feinstein said she will introduce a bill next week to strengthen the existing Border Tunnel Protection Act of 2006 by making “the use, construction or financing of a border tunnel a conspiracy offense.”
Kelly welcomes the bill.
“I think anything we can do to enhance or bolster existing authorities is good for us,” Kelly said.