The head of a special legislative panel on border security wants to use some of the money people across the nation donated to build a border fence instead for invisible buried sensors.
Sen. Al Melvin, R-Tucson, said there are places where a fence makes sense.
But Melvin, who chairs the Joint Border Security Advisory Committee, said Wednesday that a physical barrier is not always possible or practical. And the issue, he said, goes beyond whether the federal government or private landowners will give permission.
One is the fact that Tohono O’odham tribal officials have balked at putting the kind of fences along their 75 miles of international border that would stop people from crossing. Instead, the tribe, which straddles both sides of the border, has agreed only to vehicle barriers.
Melvin said buried sensors would get around the objections from environmentalists who do not want to disrupt animal migrations and have raised concerns about the effect of fixed fences in rivers and washes.
“The cables are buried a foot underground,’’ he said.
“You can’t see it,’’ he continued. “ But we can monitor it.’’
The idea comes as the tally of donations to the week-old fund to build a fence has now surpassed $100,000. That includes $106,000 contributed online by 2,400 donors using their credit cards, with another 184 individuals sending more than $10,500 in the mail.
For the time being, those funds are simply going to accumulate until the committee decides where to build the first segment — and exactly what form that will take.
A former captain in the Navy, Melvin said these sensors can be as accurate as sonar.
“When you’re in a submarine and you’re getting ‘pings,’ you can tell the difference between a passenger liner, an aircraft carrier, another submarine,’’ he said, based on the particular signature. Melvin said it’s the same here, with a human triggering a different type of signal than a rabbit or a cow.
It’s even more discriminating than that, said Rep. David Stevens, R-Sierra Vista, who is a contractor with the U.S. Department of Defense.
“The weight of the human, the length of their stride, the way the heel hits, they can tell if someone’s over 200 pounds and they can tell if someone is around 100 pounds,’’ Stevens explained. And he said sensors can even tell whether the object is walking or running, and how many people are in a group.
Like Melvin, he sees an opportunity for sensors where a fence does not make sense, like in the Huachuca Mountains south of Sierra Vista.
Then there’s the question of cost.
Stevens said one type of technology could probably be acquired for $100 for each pair of sensors necessary to track whatever comes between.
Melvin said he is looking at a buried cable that would provide coverage over a longer area. He put that price in the neighborhood of $20,000 a mile.
That is far less expensive than even the lowest estimate by Sen. Steve Smith, R-Maricopa, architect of the border fence legislation, of $400,000 a mile. And much of what already has been built along the border by the federal government is running far north of $3 million a mile.
But sensors, by themselves, are useless unless someone is monitoring them.
Melvin hopes to link them to some existing state agency which is staffed on a round-the-clock basis, like the Arizona Counter Terrorism Information Center where various local, state and federal agencies share information they gather. And if that does not work, Melvin noted the state Department of Transportation maintains an operations center in Phoenix where staffers monitor freeway cameras.