Border fence design blasted as causing flooding

Associated Press / San Diego Union-Tribune
August 23, 2008

TUCSON, Ariz. – Environmentalists say flooding caused by a newly built border security fence during a July monsoon bears out their concerns and warnings about the adverse environmental impacts of the government's rush to build fences.

The immediate case in point centers around fencing built on the Organ Pipe Cactus National Monument in southwestern Arizona. Officials say the design of the fence between the U.S. and Mexico caused debris and water backup during a July 12 storm that led to flooding at the port of entry at Lukeville and Sonoyta, Mexico.

“One of the reasons for it was the debris that accumulated on the fence itself,” said Lee Baiza, superintendent of the Organ Pipe monument, which is part of the National Park Service.
Environmental groups have been critical of the manner in which the U.S. Army Corps of Engineers and contractors for federal agencies have designed and built a range of fencing and vehicle barriers at various points along the Arizona-Mexico border.

In particular, they've denounced Homeland Defense Secretary Michael Chertoff's waiver of environmental laws to hasten construction as the Bush administration pushes to complete 670 miles of fences and other barriers by year's end along part of the nearly 2,000-mile Mexican border.

The barriers are intended to deter illegal immigrants and drug smugglers. Congress granted the waiver authority in 2005.

Critics have said the design of the pedestrian fencing being put in on the Arizona border is flawed. Much of that fencing consists of 10-foot wide and 15-foot tall steel-mesh panels, some featuring a series of wide horizontal grates at the bottom designed to let water and sediment flow through.

“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 to expect flooding there and at other Arizona locations, including next to the San Pedro River in Cochise County.

“It doesn't take an expert hydrologist to anticipate the potential for these walls to become like dams,” Clark said, “especially in flash flood type of storms, where a lot of water and debris are generated very quickly and can pile up against the fences very rapidly.”

He noted that rapidly moving runoff in washes dislodged or eroded large chunks of concrete foundations, and debris stacking up against the fence itself created barriers or dams redirecting the water, creating gullies and causing even more erosion.

Federal officials maintain that while Chertoff has invoked his waiver authority three times in Arizona, he has ordered Customs and Border Protection and Border Patrol officials to adhere to environmental requirements anyway.

“We are still required to follow every environmental rule, regulation and policy,” said Robert Gilbert, chief of the Border Patrol's Tucson sector. “He does not waive us doing what we would have to do without the waiver. So it doesn't change anything in the environment.”

The Organ Pipe monument's staff produced a report earlier this month on the pedestrian fence's effect on the 330,000-acre monument's drainage systems and infrastructure.

It concluded that the fence failed to meet hydrologic performance standards of the U.S. Army Corps of Engineers or standards set by the U.S. Border Patrol's final environmental assessment for the project.

That assessment determined that the 5.2-mile pedestrian fence would have no significant impact on the monument's environmental features.

But the recent monument report said its own staff had raised concerns last year over the fence-building plans, based on knowledge of local flash flooding and of a previously installed vehicle barrier, where debris catches on upright posts up to 12 feet apart.

The July 12 storm dumped as much as 2 inches in about 90 minutes in the area, and water running south through washes on the monument was backed up as debris piled along the base of the fence.

It created backwater pools up to seven feet deep and lateral flows several hundred feet wide that moved out of the washes, eroding some 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.

“In this case, we're catching everything,” he said.

Baiza said the fence designers are being asked to come back and study the drainages again to come up with alternatives.

In Washington, Barry Morrissey, a Customs and Border Protection spokesman, said engineers will be talking 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.

http://www.signonsandiego.com/news/state/20080823-1256-wst-borderfence-floods.html