Flooding caused by a border security fence in southwestern Arizona shows the structure is being built too quickly and without regard for the environment, critics say.
Debris and water backed up at the fence during a storm July 12, leading to flooding at the port of entry at Lukeville and Sonoyta, Mexico, and at the Organ Pipe Cactus National Monument.
"One of the reasons for it was the debris that accumulated on the fence itself," said Lee Baiza, superintendent of the monument, a lush desert tract overseen by the National Park Service.
Environmental groups have criticized how the Army Corps of Engineers and federal contractors have designed and built a range of fencing and vehicle barriers along the Arizona-Mexico border.
In particular, they've denounced Homeland Defense Secretary Michael Chertoff's waiver of environmental laws to hasten construction of the 670 miles of fences and other barriers planned by year's end along the nearly 2,000-mile U.S.-Mexico border.
Much of the pedestrian fencing on the Arizona border consists of 10-foot-wide and 15-foot-tall steel-mesh panels, some featuring wide horizontal grates at the bottom to let water and sediment flow through.
Wrong place for wire mesh?
"While the Bush administration may claim it's taking environmental impacts of the border wall into consideration, building wire mesh fences across washes prone to debris-laden floods is fundamentally flawed," Robin Silver, a spokesman for the Center for Biological Diversity, said in a statement.
Defenders of Wildlife spokesman Matt Clark said what happened at Organ Pipe validates the warnings voiced to Homeland Security before construction started.
"It doesn't take an expert hydrologist to anticipate the potential for these walls to become like dams," Clark said.
He noted that in flash floods, water and debris accumulate very rapidly and the flow can change directions quickly, create gullies and cause even more erosion.
Chertoff has invoked his waiver authority three times in Arizona, but federal officials maintain he has ordered Customs and Border Protection and Border Patrol officials to adhere to environmental requirements.
"We are still required to follow every environmental rule, regulation and policy," said Robert Gilbert, chief of the Border Patrol's Tucson sector.
Monument staff critical
A recent report produced by the Organ Pipe monument's staff concluded that the pedestrian fence failed to meet water-runoff standards set by the Army Corps or the Border Patrol's final environmental assessment.
The July 12 storm dumped as much as 2 inches of rain in about 90 minutes. Pools formed up to 7 feet deep, and flows several hundred feet wide eroded areas along patrol roads. The waters even scoured some fence and vehicle barrier foundations.
"The monument had suggested that they take into consideration everything that can happen with a weather event," particularly an accumulation of debris, Baiza said. "We had a concern that this was going to happen."
The fence designers are being asked to come back and study the drainage again to come up with alternatives, said Baiza, the monument superintendent.
In Washington, Barry Morrissey, a Customs and Border Protection spokesman, said engineers will talk with Park Service officials to discuss the findings and recommendations.
"We are anxious to look at the information contained in the report and then sit down and look at what adjustments might be made to correct the problem," he said.