This is an old article (2006), but it shows how "highly effective" a border fence or wall can be.
As Congress looks to revamp immigration policy, some lawmakers are pushing to extend fencing along the U.S. border with Mexico. Proposals range from beefing up existing fences in Arizona to constructing new fences that would span 700 miles. Those advocating expanded fencing already have a model they can look to: a fence the federal government built more than a decade ago along a 14-mile-stretch in San Diego, Calif., that borders Tijuana, Mexico.
To those on the U.S. side, the fences in urban areas between Mexico and the United States are a symbol of security. Very few sections are painted or adorned in any way.
To many Mexicans, though, the fence is either an insult to be covered up, or a business opportunity. In Nogales, Sonora, shopkeepers say they are offended that the United States built a wall between them and their twin city, Nogales, Ariz. In Tijuana, long stretches of the fence are covered in advertisements or posters. Another section has crosses and coffins nailed to it, in memory of those who died trying to immigrate.
And at Imperial Beach, which is split at the border by giant steel pillars sunk into the sand, a movie crew shoots what is billed as a “Spanish-language, science-fiction love story” with the fence as a backdrop... immigration politics as entertainment.
Before the fence was built, all that separated that stretch of Mexico from California was a single strand of cable that demarcated the international border.
Back then, Border Patrol agent Jim Henry says he was overwhelmed by the stream of immigrants who crossed into the United States illegally just in that sector.
"It was an area that was out of control," Henry says. "There were over 100,000 aliens crossing through this area a year."
Today, Henry is assistant chief of the Border Patrol's San Diego sector. He says apprehensions here are down 95 percent, from 100,000 a year to 5,000 a year, largely because the single strand of cable marking the border was replaced by double — and in some places, triple — fencing.
The first fence, 10 feet high, is made of welded metal panels. The second fence, 15 feet high, consists of steel mesh, and the top is angled inward to make it harder to climb over. Finally, in high-traffic areas, there's also a smaller chain-link fence. In between the two main fences is 150 feet of "no man's land," an area that the Border Patrol sweeps with flood lights and trucks, and soon, surveillance cameras.
"Here in San Diego, we have proven that the border infrastructure system does indeed work," Henry says. "It is highly effective."NPR.org
