On a cool but not particularly frosty December morning, a four-door truck, battle scars and all, pulls up to the kiosk at the Borderlands Wildlife Preserve off Highway 82, northeast of Patagonia.
Out gets Zach Farley. He is the crew leader this day for the field team of the Borderlands Restoration Network. The goal of this crew is to restrain the relentless erosion that occurs wherever the arid southwest landscape has been disturbed. Vast stretches have been disturbed over the prior 200 years in pursuit of profitable beef or profitable ore.
I join Zach in the truck along with the rest of his crew which this day consists of Rohan Sorta, 30, who has been on the job for 6 months, and Eduardo Gracia, 29, who has a longer work record at three and a half years. Zach is 50 and has been doing this work for five years.
We cross Highway 82 onto a dirt road that will bring us to our first stop of the morning. As we bump past mesquites, Zach tells me that he has worked on some 4,000 structures. These consist of stone-lined trincheras, or trenches, Zuni bowls, and so-called one-stone dams, or weirs.
Directing the ebb and flow of water is an ancient practice. Think Greek and Roman aqueducts. There were Mesopotamian irrigation canals 6,000 years ago. Erosion control is the art of absorbing the energy that is bound up in the flow of rushing rainwater, perhaps turning it back on itself, so that the flow can relax and hopefully seep into the ground and deposit its sediment. The damp, fresh earth should promote the growth of plants whose roots will capture the soil thereby preventing further erosion.
We come across a series of one-rock dams that Zach and his crew built last year. They get their name from their simple, low structure. Some are constructed by laying rocks end to en, like the cars on a train, and some by turning the rocks on their edges, like books on a library shelf. They are separated by about ten feet from each other in the wash. These have been here for about a year and are working, as evidenced by the silt that has already formed behind them.
We return to the truck to go to another site.
I ask about snake stories, evoking nervous laughter from all three. Last winter Zach picked up a large, heavy rock with both hands and uncovered a rattlesnake trying to sleep beneath it. “So, I just gently put it back down,” Zach says. “I don’t really like rattlesnake stories that much.”
Zach and his crew do wear guards that strap around the knee called leather gaiters. When I ask if there had ever been a day when they were really grateful for having put on their gaiters, they all reply, “No.” They had never been struck at, but better safe than sorry.
We drive a short distance up Casa Blanca Canyon Road and turn left on the north side of the Borderlands Wildlife Preserve. We are on our way to look at a Zuni bowl and trinchera complex the crew have been working on for two weeks.
A trinchera is a stone-lined pathway for water. A Zuni bowl is built to stop the undercutting action of water flowing over an elevation drop. It is composed of a head-cut pour-over, a plunge pool, a lower pour-over which is about one-half the height of the head-cut pour-over, and a one-rock dam. The length of the plunge pool is approximately two to three times the height of the head cut, and the overall length of the structure, from the head-cut pour-over to the one-rock dam, is about four to six times the height of the head cut.
“Basically, a Zuni bowl is a sealing of a head cut,” says Zach. “A head cut is formed when the water has to change elevation and dropdown. It starts cutting back. It will come down, come over the edge, and keep cutting back unless you do something about it. So we basically seal the back edge up with stone to make it stop cutting back.”
Zach says that a place that could use a Zuni bowl is Temporal Road, on the way to the Patagonia dump, which in some places has been cut down to a depth of 10 to 12 feet by the corrosive force of unchecked water. He is not a big fan of putting rubber tires in those eroded channels. “Better to use stone,” he says. “That is what came from the land and that is what should go back in.”
We make our way deep into the Borderlands Wildlife Preserve on the northwest side of Hwy 82. It is an area laced with hiking trails, including a trailhead for the 800-mile-long Arizona Trail. It is a beautiful tract of wilderness covered in the mesquite and the dry grasses typical of its semi-arid, 4,300-foot elevation. We stop to examine a place that appears to be the confluence of flow from three directions. It is a severe and extensive cutback that has threatened to take out the dirt road if not mitigated.
Empire Materials, from Sonoita, has delivered what appears to be several tons of basalt, and Zach and his crew have been working for two weeks to construct a Zuni Bowl along with a Medialuna, or half-moon, out of the rock to control the step-down of the water, slow it, and allow it to soak in. The work is accomplished with pry bars and roller bars, shovels, sledgehammers, arms, and legs. Leverage when possible and brute strength when it is not.
“It’s a bit like prison work,” says Zach, which brings a laugh from all, “but not really.”
Zach shows me a structure that they have built in collaboration with the San Carlos Apache Tribe from the White Mountain area in Arizona. (On a reciprocal trip, Zach and his crew got to work on structures on Apache lands.) Viewing the extensive complex of graceful bowls, trenches and serpentine half-moons made out of rock, earth, roots and a semi-buried log of wood, I find it hard not to think of the large works of earth art such as Spiral Jetty by Robert Smithson or the smaller, more intimate pieces by Andy Goldsworthy.
Zach shows me a one-wheeled wagon that has two handles and is low to the ground. It is one of a kind.
“We call this the Boulder Bully and I built this personally from parts,” he says. “The really neat thing about this is if you have a really heavy boulder, you can just roll it up on there, then put it all in your legs, and away you go.”
Zach holds up a large sledgehammer and says, “This is what we use to make big stones into small stones. Crack ’em open and set ’em in.”
The crew also uses metal pipes as rollers to position the more massive stones but, Zach says, “I like to have the big stones remain big stones because they are more useful that way.”
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Headquarters for Borderlands Restoration Network is at the south end of School Street in Patagonia. It is there that I meet Aspen Thies, the BRN’s Watershed Restoration Program Coordinator. Originally from Casa Grande, she is a recent graduate of Colorado State University with a degree in Fish, Wildlife, and Conservation Biology.
Aspen’s first year on the job was spent doing the physical grunt work of erosion control, which was something that she hungered for. She has since spent part of her time in the office where she works on grant management, doing reports and making sure that the team is meeting its deliverables.
Aspen tells me that most of the work that they have performed has been on public land, such as the three years spent building a thousand structures on the west side of Montezuma Pass in the Huachuca Mountains.
“Some people have come to us, especially private ranches,” she says. “We have started to work a lot more with Arizona Land and Water Trust, where they help establish conservation easements on a lot of open land and then they contract us to come in and do erosion work. It’s a really cool partnership.”