On the southwestern-most tip of the country, just across the border from Tijuana, rugged canyons drop down to a rich Pacific estuary, where millions have been spent restoring fresh and saltwater marshes that sustain the California brown pelican and other rare birds and plants.
But this landscape also represents a gaping hole in the nation’s defenses against terrorists, drug traffickers and other criminals, federal officials say.
At some points, a worn-out border fence teeters atop cliffs. In at least one spot along the sloping side of a canyon, erosion has buried so much of the fence that migrants and other travelers can step over it. Near the wind-swept shoreline of Border Field State Park, the 10-foot-tall steel panels that make up the fence are pocked with holes.
The Bush administration proposes closing off this final 3.5-mile stretch of border between the United States and Mexico by moving massive amounts of dirt from nearby mesas into canyons to create a long earthen berm. On the berm, parallel to the existing border fence, a second fence and a patrol road would be constructed.
Environmentalists say a project of that size would create an ecological disaster.
In recent years, more than 10 miles of the U.S.-Mexico border along the San Diego County line have been fortified. But objections from the California Coastal Commission and local environmental groups have stymied efforts to finish the last few miles from Otay Mesa to the Pacific.
That soon could change.
Last week, Rep. F. James Sensenbrenner Jr. (R-Wis.) introduced immigration legislation calling for the border fence’s completion.
Members of the Coastal Commission said they did not want to stop the federal government from bolstering border security, but rather believed the government could downscale the project and protect the natural setting and wildlife habitat without sacrificing security.
So far, efforts to reach a compromise have failed. That reflects, at least in part, a widening chasm between conservatives in Congress and the administration who favor a no-holds-barred approach to beefing up national security, and environmentalists and immigration advocates who argue that security should be achieved without sacrificing other values.
“There’s a compelling security reason” to complete the fence project, said Rep. Duncan Hunter (R-El Cajon), who has championed the project for more than a decade.
But opponents argue that if Congress pushed through the border proposal as planned, it would be authorizing a landfill project that would cause tremendous erosion in the ecologically fragile Tijuana River Valley area. That could threaten endangered species such as the San Diego fairy shrimp, California gnatcatcher and the light-footed clapper rail.
“It requires taking down a whole mountainside and filling in a canyon. It’s an environmental disaster,” said Rep. Bob Filner (D-San Diego), whose district includes the border area. “It destroys open space, and it is not necessarily needed or wanted by border control.”
“It’s ridiculous to destroy it all for a very minor increase in protection,” he said.
The stalemate is a rare example of environmental concerns taking precedent over national security interests post-Sept. 11. But both sides acknowledge that advocates of filling in the canyons and building new fences may be in a position to prevail.
“There’s only one guy who wants this -- Duncan Hunter -- but he has the personal power to get this in,” Filner said.
On a typical day, the area seems more like a recreation area than a security zone.
Bird-watchers tramp through the Tijuana Estuary, one of the few remaining coastal wetlands in Southern California. Local residents share the winding roads with bicyclists, horse riders and picnickers who congregate at Border Field State Park. Often zipping by on the same roads are Border Patrol agents in all-terrain and sport utility vehicles.
There is no question that the stretch of border, which includes the canyon known as Smugglers Gulch, is porous. Agents recently captured five migrants who said they jumped the fence and hid in wetlands for about an hour before being pulled out of the muck.
“Imagine, with one fence we couldn’t get across [the border], with two fences it would be much more difficult,” said Juan Carlos Vega, one of the migrants, wearing muddy pants in the back of a Border Patrol vehicle.
About 140,000 illegal migrants were apprehended crossing the border in the San Diego sector during the last 12-month period for which figures are available. The sector stretches 66 miles inland from the coast; no figures were available on apprehensions for the 3.5 miles under dispute.
The federal government wants to complete the fence project, but so far the White House has not exercised its authority to override the objections of the Coastal Commission.
“The fence ought to be completed as soon as possible,” said Robert C. Bonner, U.S. Customs and Border Protection commissioner. “We believe the additional fencing is required to give us better control of the border with Mexico.”
Quinn Palmer, a spokesman for the agency, added: “Our mission is to prevent terrorists and terrorists’ weapons from entering the United States, and to do that we’ve got to be able to detect and interdict any person illegally entering the United States. The border fence definitely would help us to do that.”
But Peter Douglas, the executive director of the Coastal Commission, said the federal government had refused to budge during a series of negotiating sessions designed to solve the security problem without causing environmental damage to the area.
“The Border Patrol and Department of Homeland Security have not been willing to make the changes that are quite simple to make that avoid the major adverse environmental impacts of the project,” Douglas said. “They have dug their heels in and said, ‘Our way or no way.’ ”
What worries the Coastal Commission most is the plan to fill in Smugglers Gulch and other canyons in the area with dirt and sand taken from the mesa above.
That would require an estimated 442,000 truckloads of dirt.
Moving that much earth would cause erosion that would devastate the wetlands and other habitat in the Tijuana Estuary, according to the Coastal Commission and outside environmental groups.
“It seems to be environmentally as damaging as possible,” said Bruce Reznik, executive director of San Diego Baykeeper, one of several environmental groups that filed a lawsuit last year alleging that the government’s plans violated environmental laws.
Environmentalists and commission officials suggested that the government replace the existing fence with a taller, stronger one in the canyons and across the beach, and add a secondary fence only on the mesas, where construction would cause less erosion.
Steve McPartland, a Border Patrol spokesman who patrolled the area for six years, said extending the fence and adding a second barrier would free up agents to patrol elsewhere and prevent most illegal crossings along that stretch.
Congressional supporters of the project rejected the notion that it endangered the environment.
“A true environmentalist would want to close that gap,” Hunter said. “The estuary gets pounded by the traffic of folks being smuggled into the United States. There have been hundreds of trails cut deep by the smugglers.”
One of the most compelling reasons to complete the project, Hunter said, is the cluster of naval facilities just north of the border that could be alluring targets for enemies of the U.S.
Navy Secretary Gordon R. England, in a letter last year in support of the project, argued that “the porous nature of this border area poses an unnecessary security risk” to the military installations.
Hunter said he was confident that Congress would approve his measure, and after more than a decade of struggle, the last section of the border fence would be reinforced.