Not all is doom and gloom on the Arizona-Mexico border. There’s a place where tranquility reigns, where ruddy ducks and great blue herons share reflective waters, where pools harbor leopard frogs and native Yaqui fish. Tall cottonwoods and dense thickets of willow provide nesting sites for raptors and migrating birds, and cover for bobcats, Gila monsters and other wildlife.
It’s hard to believe that only a decade ago, this wetland oasis did not exist.
Back then, the river system of the San Bernardino Valley, which straddles the border east of Douglas, Arizona, was on life support. The Rio San Bernardino, which coursed south into Mexico, had become a barren, sandy channel with almost no perennial plants. Cottonwood and willow trees were scarce, as were shallow pools lined with cattails and bulrushes.
The wetland cienega that once existed here had been wiped out, its water drained by a 15-foot-deep gully that cut through the valley.
“There were no trees, just lots of gullies. And the soil was like cement,” recalls Valer Austin, describing the mostly dry river running through the ranch that she and husband Joe purchased in Sonora in 1989.
The Austins had previously purchased other properties on the U.S. side of the border after visiting the area in the early 1980s. They had fallen for the starkly beautiful borderlands, a unique convergence of the Chihuahuan and Sonoran deserts with the Rocky Mountains and the Sierra Madre. Now they were facing the challenge of managing a scarred ranch that straddled the U.S. border, but one with huge potential for restoring a wetland oasis in the desert.
Security was also an issue – with migrants and drug smugglers using the gullies to get to the U.S. “The sandy washes were wide enough for illegal migrants to drive through, and so deep that we couldn’t see them,” she adds.
The Austins opted to rest the ranch from livestock grazing in order to give the streamside and river bottom a chance to recover. But what to do about the deep erosive gullies on the ranch?
They got a clue after visiting the San Bernardino National Wildlife Refuge, their nearest neighbor on the U.S. side of the border. There they learned of an old Mexican technique: the building of rock-filled, wire-basket structures — called gabions — across streams to slow flood waters and hold soil.
The goal of the 2,369-acre refuge, created when the U.S. Fish and Wildlife Service purchased the land from The Nature Conservancy in 1982, was to protect what remained of the valley’s unique wetlands – once considered the largest, most extensive in the region. To accomplish that mission, the USFWS built several rock-filled wire-basket gabions across Black Draw as the Rio San Bernardino is known on the U.S. side of the border. The gabions did the job – slowing water and catching soil for plants to grow.
Impressed with the success of this effort, the Austins decided to install gabions on their Mexican rancho. In 2005, the Austins’ foundation, Cuenca los Ojos (which translates as “basin of springs,”) hired local Mexican workers with experience building gabions.
It wasn’t long before the Austins noticed changes. Behind each gabion – some of them 40 feet across and 20 feet tall — the soil began collecting and raising the riverbed. The sediment remained wet like a sponge slowly releasing the water. Cottonwood and willow seedlings, and other plants, began to take hold.
Today, with more than 50 gabions placed in strategic locations along more than seven miles of streams, the deep gullies that formed in the early 1900s are slowly receding behind dense thickets of willow, cattail, bulrush and tall cottonwoods. Where there had been little habitat for wildlife, there are now nesting places for resident and migratory birds and pools for native fish. The thick plant growth has captured more than five feet of sediment in many places.
Along Silver Creek, which flows from the Chiricahua Mountains and meets the Rio San Bernardino south of the border, the rock structures have raised the riverbed by up to 20 feet providing a kind of wetland sponge that is the largest contributor of water downstream.
Valer is obviously proud of restoring the river system and wetlands. “Look at it. It’s starting to heal itself,” she says, standing in front of a profusion of young cottonwoods.
Back on the U.S. side of the border, current refuge manager Bill Radke stands on a knoll gazing south at the panorama before him—where refuge lands meet the Austins’ San Bernardino Ranch at the border. “It’s pretty neat to see this continuous ribbon of green within a handful of years,” he says. “The cottonwoods are doing so well. Eight years ago there were no clusters of trees.”
Inspired by the Austins, Radke and a crew last summer built a large gabion on the refuge across Black Draw, using funding and materials from the Department of Homeland Security. Sediment behind the structure has already risen and pools with insects, frogs and native fish have formed.
“This is Valer’s doing,” says Bill. “She’s the catalyst of this change.”
The surging health of the Rio San Bernardino system is also attributable to years of ranchland conservation work by the Malpai Borderlands Group, a collaborative group of ranchers, agencies, scientists and conservationists including the Conservancy. The group has built thousands of small rock structures on 15 to 20 miles of upland drainages to help stabilize soils. Controlled burns have also improved the grasslands and reduced erosion.
Another welcome change has occurred downstream in Mexico. In the early ‘90s, the river did not flow far beyond Highway 2, the major highway across northern Sonora. It had less than a mile of surface flow. Now the river flows downstream about 10 miles onto land of cooperatively owned ranches known as ejidos.
Initially ejido members feared their new neighbors, the Austins, might cut off all of their water. Instead, the opposite has occurred: their water has increased and the river is flowing year-round despite the longest drought in recorded history.
The ejidos now are building similar structures on their land with the help of the Mexican government agency CONAFOR. The ejidos are also lending labor to Cuenca los Ojos in exchange for use of the foundation’s equipment and expertise.
Having heard of the restoration of the Rio San Bernardino, representatives of the Navajo and Hopi nations have visited with Valer to learn about the potential for erecting gabions to revive rivers within their northern Arizona lands.
Native people visited the springs and wetlands of the San Bernardino Valley for centuries before Europeans arrived. Now, the San Bernardino will once again be the river and wetlands complex that Geronimo knew.
Tana Kappel is a marketing specialist and writer for the Arizona chapter of The Nature Conservancy.