Can New Mexico’s Ancient Water System Survive Climate Change?
Santiago Maestas has grown apples, peaches, and apricots on his New Mexico property for more than five decades. He still cherishes the network of ancient gravity-fed irrigation ditches that deliver the water that keeps his orchard thriving.
Those irrigation ditches, scattered across the state and known as acequias (pronounced ah-SEH-kee-ahs), have endured for hundreds of years. For Maestas and other residents in Albuquerque’s South Valley, the communal irrigation system is an integral part of life in one of the country’s most arid regions.
“It’s what makes the valley green,” said Maestas, walking along a narrow, meandering acequia near his house on a summer morning. “It provides us with a canopy. It provides us with the ability to continue to grow crops in our backyards.”
The water that day flowed through the canal, flirting with the roots of lush, towering trees lining the dirt banks that Maestas strolled. In a small ditch, the gravel bed was dry and covered in weeds, a sight emblematic of dwindling water. Scientists say a lingering drought, warmer springs, and reduced water flow in the Rio Grande will intensify and further test the ancient irrigation systems.
Acequia users like Maestas are part of a collaboratively managed irrigation system that delivers water from ditches to crops and gardens. To cope with an increasingly dry environment, irrigators are already making some adjustments to the waterflow. “We’re now on a three-week rotation,” he said. “One day every three weeks, we can deliver water. Earlier in the spring, when the river was full, we could deliver water every two weeks.”
Acequia users say the treatment of water as a commodity that can be sold and traded, like gold and silver, goes against the traditional system, which emphasizes shared resources.
As water becomes increasingly scarce in the drought-stricken Southwest, so does competition for the resource. This worries users of New Mexico’s acequias, which research shows could help offset some effects of climate change as water seeps into the soil, replenishing groundwater that helps balance the water supply during scant rainfall. To safeguard their unique system, irrigators like Maestas are working on adapting to volatile weather, boosting acequias as a sustainable resource, and strengthening legal protections around water rights in a changing environment.
Acequia users say the ever-increasing treatment of water as a commodity that can be sold and traded, like gold and silver, goes against the traditional system, which emphasizes shared resources. The canals that have long sustained people still exist because of their communal bonds and deep connection to land and water, said Jorge Garcia, a South Valley resident. Acequias are a “system that carries not only our history, but also our spiritual values.”
In a water-stressed place like New Mexico, Garcia said, preserving acequias can ensure a continued supply of clean water for those who depend on it to grow food for their families and for the local community: “We have to protect the water that we have for future generations.”
The use of shared canals and ditches to irrigate New Mexico date to before the arrival of Spanish explorers in late 1500s. When Spanish explorers arrived and expanded their occupation from Mexico into what is now the American Southwest, they built the system of acequias that could deliver water to their established settlements.
“There’s a distinction between an acequia and a canal and a ditch,” said José Rivera, a research scholar who has long studied acequia culture. “Acequia has a connotation about it that it’s both a physical system, just like a canal or just like a ditch. But acequia also means it’s a social organization of irrigators. It’s a community of irrigators.”
In other words, acequias refer both to the physical structure and the social institution that governs its use. The irrigation system relies on a network of canals that deliver water from rivers, streams, and springs. Gates open and close so the water can flow into smaller ditches that allow irrigators, also known as parciantes, to flood their land during the growing season. Each acequia functions as a democratic institution that shares water fairly during shortages. A mayordomo, or ditch boss, handles various tasks, including organizing the people, to keep the acequia running smoothly. Three commissioners, or comisionados, provide oversight.
Acequias are a “system that carries not only our history, but also our spiritual values.”
Rivera calls acequias in New Mexico “an amalgamation of all of these practices and all of these traditions and they came together here.” (Spaniards inherited the practice, which has Middle Eastern roots, during the Moorish rule in Spain.) According to the New Mexico Acequia Association, today the state has about 700 acequias considered political subdivisions subject to state laws. Meanwhile, neighboring Colorado has around 70 along its southernmost region. Acequias built in other Southwest regions, such as Arizona, before the United States became a nation have long disappeared.
Acequias in New Mexico for the most part still adhere to traditions stemming from old Spanish and Mexican legal systems that emphasize shared benefits and responsibilities, as well as unique Spanish terminology, said Rivera, professor emeritus of community and regional planning at the University of New Mexico.
The historic waterways crisscross urban and rural land, distributing water to thirsty orchards, gardens, and small fields. “Ultimately, the way that we use these resources is what has allowed our communities to survive for all these generations,” said Patrick Jaramillo, co-director of the New Mexico Program of the American Friends Service Committee in Albuquerque.
His nonprofit collaborates with those working to protect acequia traditions. “The acequieros, or the stewards here know that if we keep these practices, our communities will continue,” said Jaramillo, who grew up on an acequia property.
Although the antiquity of acequias affords them certain legal protections, their endurance has not been without struggle. The growth of water users and changing laws that champion water rights as individual property have meant frequent clashes with the communal concept of acequias.
In the early days of modern southwestern settlement, acequia water could not be legally diverted from ditches. Now, parciantes can sell their rights to their share of water even if they keep their land.
“In the past, water rights could not be transferred outside of the community,” Rivera said. “Now they can. They’re bought and sold, like any kind of property. So that’s a major threat.”
Acequias increasingly defend their way of life through political activism. They’ve adopted bylaws as acequia associations to restore governance abilities as owners of some of the state’s oldest water rights. Although parciantes have individual water rights, the irrigation system itself is owned and managed collectively as a common property, Rivera said.
Acequia communities have the right to protest proposed water transfers they deem could be detrimental to the function of their system. According to the Acequia Governance Handbook, acequia associations that have not adopted transfer bylaws that give them rights can express concerns in public hearings, but the New Mexico Office of the State Engineer, which regulates water rights, has the final word.
“We have to protect the water that we have for future generations.”
A water transfer diverts water destined for an acequia to a new location, for example. The practice sometimes pits parciantes against parciantes. In the South Valley, people seek water transfers for economic reasons, because they’re moving, or simply because they have no need to irrigate, Garcia said.
One of the South Valley acequias is now protesting a parciante’s plan to sell and transfer water rights to a cannabis farm. Protesters argue that the sell-off of too many water rights from an acequia could eventually lead to its collapse. Parciantes also have opposed proposed high-density development they say would impair water resources, including acequias.
Garcia adamantly opposes any development that could jeopardize water rights in acequias. He feels the same about water transfers from parciantes that could deplete water flows in acequias and hurt other irrigators. “The individual right is conditioned and dependent on the collective right,” he said. “Why? Because the system is designed to function with gravity. So the more water you take, the less pressure there is, the more difficult it gets to distribute water.”
Maestas put it this way: “There’s not enough water for the city of Albuquerque and the acequias and the farmers.”
The surface water that keeps acequias flowing in the South Valley and other traditional irrigation systems across the state originates as winter snowpacks in the Rocky Mountains of southern Colorado. During spring, the snowmelt runoff from the mountainous headwaters of the Rio Grande travels south through New Mexico and then becomes the international boundary between Texas and Mexico.
The water channeled from the river into acequias has kept sustenance farming alive for generations and, over the years, allowed some growers to expand food production in their communities. But decreases in snowpacks causing diminished and variable stream flows are projected to worsen with the higher temperatures of global warming.
“The acequia communities, they’re right on the frontline of these changes,” said Caitriana Steele, an associate professor in the department of plant and environmental sciences at New Mexico State University. “They’ve got no way to store water, really. The snowpack is their storage.”
“There’s not enough water for the city of Albuquerque and the acequias and the farmers.”
There’s already evidence that the changes in temperatures are causing the snowmelt that fills acequias to happen earlier in the spring, which complicates irrigation, said Alexander “Sam” Fernald, director of the New Mexico State University’s New Mexico Water Resources Research Institute. This means depleted flows in the summer, when the demand for water soars.
“We’re already seeing reduced runoff, and we’re expecting in the near future to have up to 25 percent less runoff,” Fernald said. “We’re not there yet, but we’re already seeing less runoff for a given snowpack.”
Severe weather, including drought and wildfires, and how it could affect the ability of acequias to continue providing water for communities worries many. In 2022, flash flooding damaged several acequias in various parts of the state.
“The current drought affecting the Southwest United States is probably the worst drought in 1,200 years,” said Tom Swetnam, professor emeritus of dendrochronology at the University of Arizona in Tucson. Tree ring data shows that acequias have withstood similar dry conditions for up to 150 years.
The scientist, who now lives in the New Mexico mountains, said he’s seen firsthand the damage that wildfires can do to the traditional irrigation systems. “The acequias and the places where they’re catching the water from the rivers get filled up with sediment from post-fire erosion,” he said.
Fernald, who has long studied acequias, said their collaborative nature has factored into their survival during tough weather events over the years. Their water-sharing principles, he said, could continue to help them withstand precarious times to keep irrigating their crops.
Tree ring data shows that acequias have withstood dry conditions similar to today’s drought for up to 150 years.
Although acequias lose a good amount of water to evaporation when they soak crops and gardens through flood irrigation, studies show that their hydrology provides benefits to the environment that may actually help counter the loss. For example, Fernald’s research found that seepage — which can range from about 7 to more than 50 percent of the flow — recharges the aquifer and eventually returns to the river. “Acequias also provide many benefits for riparian habitats,” he said.
He likened acequias to beaver dams that keep the water in the upper watershed, by spreading it out over fields, and soaking it back into the groundwater. “It delays its flow downstream, so that’s actually really good for the downstream because there’s water in the river later in the summer,” Fernald said.
For Santiago Maestas, keeping the water flowing to all acequias in the South Valley and across New Mexico is paramount. He cannot fathom a day when the water won’t run down a ditch to quell the thirst of his orchard, or a neighbor’s garden, or a farmer in the northernmost reaches of the state, he said: “The acequias are the lifeblood of this area.”
The 29 square miles that make up the unincorporated South Valley community are home to about 37,600 residents, 82 percent of them Hispanic. Families who have lived on land-grant acequia properties for generations mingle with neighbors who have moved in throughout the years and adopted their communal irrigation traditions that emphasize sharing water when it’s plentiful and rationing it when it’s meager.
In 1973, Maestas moved into his South Valley half-acre property, which included an acequia that carried water to the alfalfa he grew. But the death of the mayordomo left the ditch unattended. It later fell into disrepair, which left Maestas without access to water. Looking for a way to irrigate again, Maestas went on a mission to unlock the time-honored intricacies of the acequia system.
After attending workshops and poring over books on water laws and policy, Maestas discovered that his property came with pre-1907 water rights. That year produced the water code that gives the state the power to control water use and protects water rights established before the date. Such rights are the only ones that can be used without state approval.
Maestas set out to regain water access and inform longstanding acequia users that claiming pre-1907 water rights leaves no doubt of legal standing as competition for water intensifies. Many South Valley residents were, and still are, unfamiliar with a benefit they may have, he said. That’s something Maestas, now as president of the South Valley Regional Association of Acequias, works to change.
Acequias in the South Valley dealt with significant disruption when the Middle Rio Grande Conservancy District created in the 1920s eventually took charge of surface water in the region. Unable to pay the quasi-public agency’s required taxes for new drains, canals, and other infrastructure, acequia associations faltered amid the changes.
Nonetheless, they never ceased to function as a group of parciantes working for the common good, said Garcia, who also is the executive director of the nonprofit Center for Social Sustainable Systems. He and Maestas have worked for years to revitalize acequias and promote understanding in the values and practices of the longstanding institutions.
The two men and other acequia advocates gather once a month at a local waterway with area residents interested in learning about the agricultural tradition and ongoing efforts to preserve them. In July, a group listened to Maestas talk about the history of the five ancient acequias that run through the South Valley.
“The whole irrigation system in the South Valley starts here,” Maestas told a circle of people standing in the shade of two imposing cottonwoods on a late morning. In the distance, a thicket of trees tinted the landscape yellow green.
In the past, Maestas said, the spring runoff that feeds the Rio Grande would wash out the earthen ditches and irrigators had to rebuild them every year. “In many parts of the valley here, the river is actually higher than the valley.”
These days, levees built by the conservancy district keep the river from overflowing into the valley. “So they’re critical and they require federal money because it takes millions of dollars to construct these — more than whatever we could pay with our property tax fees and our water service fees,” Maestas said.
“Without water, we’re not going to be here. And that is something that we’re going to have to reckon with very, very soon.”
Among those listening were about a dozen kids who arrived on bikes. They were part of Story Riders, a bicycling program that offers cultural and environmental education for youth. The group was riding along the acequias daily, documenting the status of South Valley ditches in a report they planned to share with the conservancy district, said program manager Marco Sandoval.
The program works to connect youths with New Mexican culture and acequias are a significant part of it, Sandoval said. “Water is an important issue here,” he added. “Without water, we’re not going to be here. And that is something that we’re going to have to reckon with very, very soon.” Today’s youths could one day help preserve acequias as a sustainable system that can still grow crops and help improve food security in a harsher environment, Garcia said, and with the effects of climate change expected to worsen, “the right thing to do is to get closer to natural systems and acequias give us that opportunity.”
In the meantime, Maestas expects to keep doing his part to protect acequias. “Basically, this is our legacy,” he said. “It’s our role now to be the stewards of the acequias.”
This story was supported in part by The Water Desk at the University of Colorado Boulder’s Center for Environmental Journalism.
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