Along a Desert River, A New Breed of Rancher

Rancher Paul Schwennesen in the riparian forest along the San Pedro River, which abuts his land. Schwennesen is shifting to native grasses and water-thrifty crops to save water for the river. Photo by Sandra Postel

“I don’t know what I pump and I don’t care – and that’s crazy,” says Paul Schwennesen, a fit, energetic rancher in his late thirties who might outcompete Clint Eastwood for most handsome cowboy.

On his modest-size ranch, the Double Check, located in the lower San Pedro River Valley of southeastern Arizona, Schwennesen raises cows to supply grass-fed beef to farmer’s markets and seventeen restaurants in Phoenix and Tucson, both cities about an hour-and-a-half away. Schwennesen’s ranch abuts one mile of the San Pedro, and, as an irrigator, his pumping of groundwater contributes to the depletion of the river’s base flow, the current that keeps the river wet and connected during the dry season.

In contrast to most irrigators in the West, Schwennesen wants to be made to care how much groundwater he pumps. A decade ago, he took over operations at Double Check from his father, who now raises cattle in the high country near the Arizona-New Mexico border. Schwennesen is a successful rancher and businessman, but cares about the river, too. In his mind, free water is no friend to the river or the long-term health of the community, and he wants to see water better valued.

“I am a free-market devotee,” Schwennesen said. “Markets are the best way to allocate scarce resources. We’d love to see a market established for water.”

Schwennesen is among a new cadre of farmers and ranchers that brings a more holistic, ecological way of thinking to land management.

“Water is the salient variable in these environments,” he said, as we examined one of his experimental fields on a warm, late-May morning. “Anything you can do to alter the water regime is going to have the biggest effect. And the more organic matter we can squeeze back into the soil, the more water.”

It’s a belief backed by science, and it’s at the core of Schwennesen’s mission. “Well managed land can give back more than it consumes,” he added. “That’s the miracle of it.”

Paul Schwennesen discusses the importance of roots with me in one of his experimental fields. Photo courtesy of Arizona Land and Water Trust.
Paul Schwennesen discusses the importance of roots with me in one of his experimental fields. Photo courtesy of Arizona Land and Water Trust.

I’ve come to the Double Check smack in the middle of the driest time of the year, typically April to June. The much anticipated El Niño of 2015-16 did not deliver the rains most had hoped for. Just a short distance from where we stood talking, the San Pedro’s channel was dry. Historically this portion of the lower river had flowed intermittently, but over time groundwater pumping and prolonged drought have depleted the base flow and dried up the channel, a condition that’s bothersome to Schwennesen.

The San Pedro is the last major undammed river in the American Southwest. Unlike the Colorado River and the Rio Grande, which flow south toward Mexico, the San Pedro originates in Mexico and flows north some160 miles before joining the westward flowing Gila River near the small town of Winkelman.

It is a winding ribbon of green in the desert that offers biological riches far out of proportion to its size. The gallery forests of cottonwoods, willows and mesquite that band both sides of the river provide some of the best remaining habitat for birds and wildlife in the American Southwest.

More than three hundred species of migratory songbirds seek out the San Pedro corridor as they journey between their wintering grounds in Central America and Mexico and their breeding grounds in the United States and Canada. More than fifteen percent of the world’s known population of western yellow-billed cuckoo breeds along the San Pedro. The river system also sustains some eighty species of mammals – one of the richest assemblages of land mammal species found anywhere in the world – as well as more than forty species of reptiles and amphibians.

A flowing San Pedro, the last major undammed river in the American Southwest. Photo courtesy of Arizona Land and Water Trust.
A low-flowing San Pedro, the last major undammed river in the American Southwest. Photo courtesy of Arizona Land and Water Trust.

For such a modest river, its ecological wealth is extraordinary. But irrigated agriculture, copper mining, and in the upper reaches of the valley, urban growth have placed that wealth in jeopardy. Without the ability to reduce groundwater use and keep the river healthy and flowing, the San Pedro’s bounty and beauty will be sacrificed.

That’s where Schwennesen comes in. He has partnered with the Tucson-based Arizona Land and Water Trust and hydrologists at the University of Arizona to see if he can ranch successfully and profitably while cutting his water use by some 20-30 percent. The strategy is to shift to low water-use crops that include a mix of native perennial grasses and an annual rye crop that is seeded directly into the green vegetative cover, avoiding the tillage action that can erode and dehydrate the soil.

With deep and resilient root systems and microbial activity boosting the level of organic matter, the soil should hold water like a sponge, Schwennesen says, reducing the need for irrigation water and helping to replenish the aquifer that feeds the river’s base flow.

[Disclosure: Change the Course, the national freshwater restoration initiative I co-created has modestly supported the Trust’s investment in this innovative effort.]

Cows graze at Double Check Ranch earlier in the year. Photo courtesy of Arizona Land and Water Trust.
Cows graze at Double Check Ranch earlier in the year. Photo courtesy of Arizona Land and Water Trust.

As we hop a barbed-wire fence and head down to the river, bushwhacking through the dense riparian forest, we hear a yellow-breasted chat, a gray hawk and a yellow-billed cuckoo. “It literally brings joy to my heart to walk through here,” Schwennesen says.

In contrast to many riparian areas in the Southwest, where invasive tamarisk (also known as salt cedar) can comprise 60 percent or more of the vegetation, here it makes up less than 30 percent. As desert rivers lose their natural flow patterns as a result of dams, diversions and groundwater pumping, the native cottonwoods and willows give way to the aggressive invasive. But here the natives still dominate, which is good for the birds and the ecosystem as a whole.

But whether the operation at Double Check can thrive on substantially less irrigation water is the million-dollar question – not only for the San Pedro Valley, but for the entire West, where thirsty alfalfa and other hay crops top the list of big water consumers. Under an agreement with the Arizona Land and Water Trust, Schwennesen has agreed to cut his water use on twenty-four acres of experimental fields by 110 acre-feet (35.8 million gallons) over two years. That’s a drop in the bucket, but the experiment is designed to try out several different water-saving approaches and compare the results to determine what works best.

Up until the project at Double Check, the Trust’s Desert Rivers Program had mostly paid farmers to free up water for nature by fallowing their land. But the partnership with Schwennesen is an attempt to keep land productive while replenishing the aquifer and the river. Probes placed in the soil will allow hydrologists to measure the volume of water consumed by the native grass-rye pasture mix. A gauge on the well documents Schwennesen’s water use.

Cameron Becker of the Arizona Land and Water Trust reads the gauge on Schwennesen’s groundwater well. Photo by Sandra Postel
Cameron Becker of the Arizona Land and Water Trust reads the gauge on Schwennesen’s groundwater well. Photo by Sandra Postel

“It’s one of our most exciting projects because we’ve got all this monitoring going on,” said Scott Wilbor, project manager with the Arizona Land and Water Trust. “And Paul is already coming from a conservation-minded background. He’s the best partner we could hope for.”

As part of the agreement, the Trust compensates Schwennesen for the value of the 110 acre-feet he has agreed to leave in the aquifer, effectively putting a price on his water for the first time.

This forward-thinking rancher is obviously pleased about that – and if the cottonwoods, willows and birds could weigh in, no doubt they would be, too.


Sandra Postel is director of the Global Water Policy Project, Freshwater Fellow of the National Geographic Society, and author of several books and numerous articles on global water issues.  She is co-creator of Change the Course, the national freshwater conservation and restoration initiative that has restored billions of gallons of water to depleted rivers and wetlands.

Sandra Postel is director of the Global Water Policy Project and author of Replenish: The Virtuous Cycle of Water and Prosperity. From 2009-2015, she served as Freshwater Fellow of the National Geographic Society. Sandra is also co-creator of Change the Course, the national water stewardship initiative awarded the 2017 US Water Prize for restoring billions of gallons of water to depleted rivers and wetlands. The recipient of several honorary degrees, she works to bridge science, policy, and practice to promote innovative ways of securing water to meet both human and ecosystem needs.
  • Steve Cullinan

    I have to point out that the Gila River is also without Dams, with the exception of some modest irrigation diversions. The battle to keep it that way is ongoing, between the NM Interstate Stream Commission and those that value free flowing rivers and the ecosystems they support. Of course, the San Pedro is a tributary of the Gila as you point out – so maybe that is the point of confusion with your statement!

    • Steve, the Gila in New Mexico remains undammed, but it is dammed as it flows through Arizona. The San Pedro, however, remains undammed throughout is length from Mexico to its confluence with the Gila. Thanks for commenting!

  • Basia Irland

    I join the 300 species of migratory songbirds along the San Pedro in congratulating this rancher on his efforts. And hats off to Sandra for always working toward a “more holistic, ecological way of thinking.” Thanks for this important article!
    Basia Irland, New Mexico, June 7, 2016

  • Michael Freshwater

    Both Arizona Land and Water Trust and Nat Geo – keep up the inspiring good work. Nationally, we need more progress going forward to protect our number one liquid asset, water.

  • Steve Fesch

    The elk River dwarfs the San Pedro river as the largest undamed river. It originates in the zirkle mountain range and flows into the yampa river in steamboat. The San Pedro is not the last. Quite frankly it doesn’t Even come close to the size and volume of the elk.

    • Thank you — I was referring to the San Pedro being the last undammed river in the Southwest. While the Elk is part of the Colorado River system, I think of it as a western river, but not a southwestern river, given its location. Its riparian environment is quite different from the Gila, San Pedro, Verde and other southwestern rivers. But thank you for calling it out! And the Yampa into which the Elk flows is undammed as well. Thank you.

  • kelly cranston

    I would also like to mention the San Francisco of New Mexico and Arizona as the least known undammed river in the southwest. “The Glen Canyon of New Mexico”.

    • Thank you! I love these comments – a great way to talk/learn about rivers.

  • Rick Gauger

    The gentleman would have been more correct if he had said “A well-regulated market is the best way to allocate resources.” History shows that we cannot count on ranchers to raise beef sustainably.

  • Bill TAYLOR

    Might add–with a nod to the birds mentioned–that the ranch also is listed by the Audubon Society as ‘Liz’s Grove,’ an IBA (Important Bird Area), an international recognition.
    A plac on a solitary old mesquite tree in the meadow commemorates the area to Liz Van Horn, who passed away some 9 years ago.

  • Sandra Hadley

    Hi Sandra,
    Hats off to you! Thanx for caring and helping others to care.

About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (dbraun@ngs.org)

Social Media