On Navajo lands, ancient ways are restoring the parched Earth

Farming once thrived in the Black Mesa region, before overgrazing and climate change wreaked havoc with the land. Today, the Navajo are restoring their watersheds—and boosting their food sovereignty—with earthen berms and small dams made of woven brush, sticks, and rocks.
Danielle Kaye builds a berm spillway on the farm of Roberto Nutlouis. The berm holds back water, flooding the cornfield behind it.
Danielle Kaye builds a berm spillway on the farm of Roberto Nutlouis. The berm holds back water, flooding the cornfield behind it. Credit: Roberto Nutlouis via Yale Environment 360

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This story originally appeared on Yale Environment 360.

Here in Burnt Corn Valley, smack in the middle of the Navajo reservation’s vast Black Mesa region, the hilly land both craves water and is brutalized by it. The sandy Arizona soil cracks under a punishing August sun as red-striped blister beetles search for moisture across its baked surface. Cottonwood trees and sagebrush rise from deep gullies carved by floodwaters that, during the intensifying summer monsoon, sluice off surrounding mesas and wash away fragile topsoil — reminders that with climate change, even quenching rains harbor powers of destruction.

This portrait of climatic havoc belies a softer reality, though. Farming once thrived in this parched region and could once again — if the right practices are adopted. Exhibit A: The crops on Roberto Nutlouis’s 12-acre Sliding Rock Farm, in his reservation hometown of Piñon, a five-hour drive north of Phoenix. “The corn is actually pretty big and thriving,” Nutlouis says. He believes — and both Western science and the lived experience of his Native elders affirm — that the traditional rock and stick structures he’s built on his property, which help store water and prevent erosion, have a lot to do with it. These structures, similar to those used by Native peoples long before Europeans arrived on the continent, are not only delivering water to crops (the broader, 27,000-square-mile reservation has the highest reported rate of food insecurity in the U.S.). They are also restoring Nutlouis’s watershed and those of his neighbors, helping to sequester carbon, and reviving this high-desert ecosystem. It’s all part of a bigger effort among a range of local and regional grassroots organizations to build back the reservation’s fragile, depleted ecosystems and bring greater sovereignty over food, water, and health to its communities.

Diné (the Navajo name for themselves) are well aware that climate change is making the weather on their semi-arid plateau weirder, wilder, and more destructive. Depending on elevation, precipitation in Black Mesa averages 6 to 16 inches a year; recent heat extremes — the Navajo government declared a state of emergency in 2023 due to soaring temperatures —mean that the scant water evaporates more quickly. Climate models predict the region will experience increasing droughts that decimate plant life, part of a growing trend of human-caused desertification across the globe, as well as higher-intensity seasonal rainfall, which can sweep away crops and roads. The ecological health of the reservation has also been weakened by deforestation from timbering operations and from overgrazing over the years.

Still, this season, Nutlouis, 44, has been able to skip his usual two-hour roundtrip drive to a reliable well to haul water home for his corn. His crop is healthy and hydrated because his land still holds last winter’s snowmelt. Clearly, his heavy labor over the past 20 years — during which he has built woven brush dams, gabions (wirework cages filled with rocks), earthen berms, concrete spillways and trenches, limestone aprons and walls, and stone-lined “Zuni bowls,” which stabilize eroding streambeds — is paying off.

Diné and others living in arid zones around the world have long used structures made of naturally occurring materials to capture and control water to grow crops and to mitigate the devastation of floods in ephemeral stream systems. Various Puebloans, including Zuni and Hohokam, used similar devices, as did the Aztecs. Arab peoples and tribes in India have incorporated stone water diversions for thousands of years. “[M]ost traditional Indigenous communities are not passive observers of nature,” writes Lyla June Johnston, a Diné anthropologist and community organizer. Instead, they are “influential facilitators of landscape scale abundance, rooted in an ethic of kinship and reverence.”

Time and again over the last 15 years, Laura Norman, a research scientist with the U.S. Geological Survey, has seen evidence that when these structures — which Norman calls Natural Infrastructure in Dryland Streams, or NIDS — are placed in gullies, they slow water to mitigate erosion, collect nutrient-rich sediment and plant debris that nourish both crops and wild plants, help store carbon, improve groundwater recharge, and increase downstream water availability by as much as 28 percent. “It’s a snowball effect that counters degradation, and you get all of these ecosystem services,” she says.

The structures on Nutlouis’s farm are integral cogs in a larger system of floodplain farming. It works like this: Nutlouis’s property lies in an alluvial fan, where mineral-rich sediments and plant waste atop mesas and other uplands wash down onto flatter ground with rainwater, snowmelt, and spring water. Across the valley, similar farms rely on this kind of system, many of which feature stone and stick constructions that Nutlouis helped build. The organic materials trapped behind the structures, says Jonathan Sandor, an emeritus agronomy professor at Iowa State University, “are a major input into keeping the fertility of the soils up.” Such small watersheds are optimal: “These gentle slopes and small watersheds allow runoff but reduce the possibility of high runoff velocities that may damage crops,” Sandor explained in a 2008 paper.

Whether rock walls or ramps, hand-dug depressions in the soil, earthen walls, or branches plaited into dams, NIDS splash water over a wider area and slow its flow so it can better soak into the soil. Many trap sediments behind them, fertilizing whatever grows nearby. The stone structures create a hyperlocal cooling effect, especially when they’re combined with shade-making vegetation.

Here, too, smallness is a boon. “Even tiny little one-rock dams can make big changes on the landscape,” Norman says. Up to five kilometers downstream from such structures, “we’ve documented increased vegetation despite drought. We’ve also documented [increased vegetation] up to one kilometer upstream, which indicates water availability.” In this way, an alluvial farm and its NIDS can support plants both sown and wild.

“The moisture we get from winter precipitation is really important for the corn to germinate and grow,” says Nutlouis, “and the monsoon rain is really important to finish our harvest of corn and squash and melons.” He acknowledges that in practice this can look chaotic, with cornfields flooded up to their ears before the water trickles down to the next field.

Workers construct a rock apron to slow the flow of stream water and stem erosion. Credit: Roberto Nutlouis via Yale Environment 360

But lately, climate change has thrown extra challenges at the reservation. “There’s a serious soil moisture deficit that’s causing a lot of ecological shifts,” Nutlouis says. Much of Black Mesa’s pinyon forest, he says, has succumbed to two decades of drought. Historically, Diné have foraged for pinyon pine nuts. They are an important component of food sovereignty on the reservation, and their loss is acutely felt.

But the ecosystem services provided by Nutlouis’s structures on his farm and elsewhere do seem to be meeting those climatic challenges. He’s noticed small juniper trees popping up on hillsides around his property despite the dryness; A cottonwood tree towering over one cornfield is also lush and full. “The idea that Earth will restore itself with natural seed dispersal” after NIDS begin to do their job “has been my observation,” says Norman. Or as Nutlouis puts it, “We’re allowing nature to do its own thing and restore itself.”

Still, Nutlouis is inclined to help the process along. His nonprofit Nihikeya (loosely translated as a collective ecological footprint) collaborates with a variety of local and regional grassroots groups that work on food, water, and justice issues, like Tolani Lake EnterprisesFirst Nations Development Institute, and the Ten Tribes PartnershipDiné C.A.R.E., another collaborator, is an environmental justice organization that advocates for community health and land rights across the reservation, as well as for the cleanup of coal- and uranium-polluted rivers and aquifers. “We especially want to support a lot of renewable projects through solar and wind, and we want to support agriculture too, because having a robust food system is a form of revenue for local farmers,” says executive director Robyn Jackson. “It also helps with continuing our cultural traditions.”

Nihikeya also works closely with the water-rights organization Tó Nizhóní Ání, whose members are collecting native plant seeds to restore riparian habitat across Black Mesa. Some of those native plants, like wolfberry, are edible, which will also help improve food sovereignty and security. “We understand that rebuilding watersheds is going to be key to continuing farming into the future,” says Tó Nizhóní Ání executive director Nicole Horseherder.

To house accessions of pinyon and juniper, willow, wolfberry bush, three-leaf sumac, and rabbit brush, Nutlouis is building a seed bank. When put back into the landscape, these plants will help keep the ground moist and mitigate erosion.

Nutlouis is working on his master’s degree in sustainable communities at Northern Arizona University, where he studies the Western science that qualifies and quantifies the benefits of traditional practices. But he is also adamant that watershed restoration success is predicated on reforging ancestral kinship connections — that is, on returning the power to make land-use decisions to clan mothers, who were traditionally Diné leaders in this arena. To that end, he’s been meeting with neighbors in one tiny watershed of Burnt Corn Valley after another to discuss how to improve the health of their land, whether for growing corn or just ensuring roads remain intact when it rains. So far, Nutlouis has helped restore 56 fields across the valley, with more NIDS than he can count.

Roberto Nutlouis’ farm. Credit: Roberto Nutlouis via Yale Environment 360

“If we can meet with all of these families [in the valley], and show them aerial maps… we can come up with a watershed development plan” for each of them, he says. “Then we can use that as a template as to how we’re going to organize with the community in the next watershed.” Improving multiple small watersheds in this way may lead to a cooler regional climate and greater water availability for all, says Norman. One of her NIDS study sites saw its water availability extended from three months to four months. “You can envision how important that is for arid lands,” she says.

“We’ve been doing this kind of farming way before the Europeans came, and that’s what our ancestors were known for,” says Nutlouis. “The work we do is looking back at ancestral wisdom, reclaiming and re-correcting knowledge, de-colonizing and re-Indigenizing.” He continues, “Ecologies needs to be restored. Food systems need to be restored. This is an opportunity to begin developing localized food economies. There’s a lot of potential in that, but we got to do it right.”

Reporting for this piece was supported by a media fellowship from the Nova Institute for Health.