Construction of two miles of border fencing in the San Pedro Riparian National Conservation Area will resume following Homeland Security Secretary Michael Chertoff's decision Monday to invoke a waiver that exempts border fences from any law.

Chertoff's move brought a swift end to a legal challenge from a pair of environmental groups that prompted a federal judge to bring construction to a halt on Oct. 10. That restraining order would have expired Wednesday. Instead, construction will resume soon, although the department didn't disclose the exact date.

The department was confident it would have prevailed had the legal process continued but said it couldn't afford to waste any time, said Veronica Nur Valdes, a spokeswoman for the Department of Homeland Security.

"The secretary determined basically that any further delay in construction would present a risk to our nation's security," Nur Valdes said. "We know that this area in particular is highly trafficked by illegal entrants . . . that this area is a known vulnerability."

The Border Patrol made 19,000 apprehensions of illegal border crossers in the area in the recently completed fiscal year 2007, a significant increase from 2006, according to Homeland Security. The agency's Tucson Sector, which stretches from the western edge of New Mexico to the eastern edge of Yuma County, has been the busiest stretch of U.S.-Mexican border for illegal immigration since 1998.

The use of the waiver marks the first time Homeland Security has invoked it in Southeastern Arizona.

The decision drew the ire of environmentalists and opponents of the waiver provision granted to the Homeland Security secretary in the REAL ID Act of 2005. Chertoff waived a record 19 laws in the waiver, said officials with Defenders of Wildlife.

"The more times that the Real ID waiver is used, the easier it's going to be to use it in the future," said Sean Sullivan, executive committee member of the Sierra Club Rincon Group, which covers Southeastern Arizona. "Unless something changes, it's likely that DHS will just waive all laws."

Even though the move didn't surprise Sullivan, he said he was deeply disappointed considering the ecological significance of the San Pedro Riparian National Conservation Area.

Home to hundreds of species of birds, mammals, amphibians and reptiles, and the last remaining free-flowing river in Arizona, the San Pedro has earned international recognition as a rare treasure. In 1988, Congress established a 40-mile stretch of the upper river as the nation's first Riparian National Conservation Area.

"I'm hoping that people will start opening their eyes to exactly what is going on here," Sullivan said. "This is a national issue concerning our entire border and many different ecosystems that are being cut in half. I don't know if I can convey how disappointing this is for this area."

Rep. Raúl Grijalva, D-Ariz., who has sponsored a bill that would, among other things, repeal the waiver, called the decision a mistake and a chilling commentary on the state of border affairs.

"That power in the hands of this administration is a very dangerous thing," Grijalva said. "It's always heavy-handed. There is no consultation, and there is no working toward consensus or compromise; it's my way or no way."

Rep. Gabrielle Giffords, D-Ariz., whose district includes the river, also expressed disappointment in Chertoff's decision.

"Homeland Security must listen to the environmentalists and border residents of Southern Arizona before resuming fence construction," Giffords said in a statement. "My goal is to balance strong border security and legitimate environmental concerns."

But some residents who live near the San Pedro River in Cochise County and deal with the impact of illegal border crossings applauded the agency's decision. Walt Kolbe, owner of the San Pedro River Inn, says a fence is needed to slow the traffic.

"It's great news," said Kolbe, who lives about seven miles north of the border on the river. "There's no telling how long the legal process will take and in the meantime, hundreds of illegals are streaming across the border."

Homeland Security plans to erect barriers across the approximately 2 miles of border in the conservation area. The proposal calls for 4- to 6-foot-high vehicle barriers made of old railroad rails in the riverbed and washes and 12- to 14-foot-high pedestrian fences along the rest of the conservation area. This would extend 30-plus miles of nearly continuous barriers that begin east of Douglas.

The two environmental groups argued that the San Pedro Riparian Conservation Area is an irreplaceable national treasure that would be irrevocably damaged by the fencing. They say that Homeland Security failed to carry out an adequate environmental impact statement.

Homeland Security officials have defended their environmental assessment and refuted the dire predictions from environmentalists. They point to backing from the U.S. Fish and Wildlife and the Bureau of Land Management, which manages the conservation area, both of which signed off on the construction project.

Chertoff's decision doesn't mean Homeland Security will skirt its environmental stewardship responsibilities, Nur Valdes said. The department has agreed to work with a Fish and Wildlife biologist to monitor area wildlife; remove temporary vehicle barriers from the riverbed each monsoon season; and take steps to prevent the introduction of invasive weeds to the area, she said.

Ultimately, the barriers will cut down on illegal immigration through the area and diminish the trampling and trash left behind, which will help conserve the important ecosystem, Nur Valdes said.

"It will be something positive to the preservation of the border environment," Nur Valdes said. "We will give people an opportunity to be able to better enjoy the area."

Did you know?

Congress granted the secre-tary of the Department of Homeland Security the power to waive environmental and other laws to build border barriers when it passed the REAL ID Act in 2005. Section 102 of the law allows waivers of any and all laws necessary to ensure expeditious construction of the roads and barriers in vicinity of the international border.

Homeland Security has used it twice before to move ahead with fence construction: in 2005 in San Diego, and in January of this year on the Barry M. Goldwater Air Force Range in Southwestern Arizona.

● Contact reporter Brady McCombs at 573-4213 or