The Christian Science Monitor reports on the building and impact of the border fence between the US and Mexico.
From the Christian Science Monitor:

The triple-and double-layered fence here in Yuma is the kind of barrier that US lawmakers – and most Americans – imagined when the Secure Fence Act was enacted in 2006.

The law instructed the Department of Homeland Security (DHS) to secure about one-third of the 1,950-mile border between US and Mexico with 700 miles of double-layered fencing – and additionally through cameras, motion sensors, and other types of barriers – by the end of the year to stem illegal immigration.

Bankrolled by a separate $1.2 billion homeland security bill, the Secure Fence Act would, President Bush said in 2006, “make our borders more secure.” By most recent estimates, nearly half a million unauthorized immigrants cross the border each year.

On the ground, though, things have turned out differently.

In certain areas along the border, the fence is creating an impact. Yet, human smugglers are simply moving to other areas where enforcement is weak and causing a rise in violence.

Strengthening border security in Yuma may be diverting illegal immigration to rural and desert areas.

“For the Yuma sector, the numbers are telling us that the wall has had a dramatic effect,” says Ken Rosevear, president of the Yuma Chamber of Commerce. “But we all know that once you shut down a pipeline in one area it merely diverts the traffic to somewhere else.”

In this case, the Tohono O’odham Indian Reservation and Saguaro National Monument to the east are seeing a rise in foot traffic, he says.

Also of concern is the increase in border violence by drug and human smugglers, who seem to be more desperate now that one of their primary entry routes has been choked off. Two months ago, a border patrol agent was intentionally run over and killed in the Algadones Dunes area, in the Yuma sector, where thousands of off-road vehicles have provided cover for smugglers moving illegal migrants north in SUVs.

Assaults on agents and rock-throwing at border patrol vehicles have gone up, says senior agent Derek Hernandez, who has been patrolling the Yuma sector for the past three years.

The market of human smuggling on the US-Mexico border is worth $7.5 billion.