Arid and semi-arid lands develop when climatic conditions create water limitations and the water lost through evaporation exceeds the water gained from precipitation. Severe water limitations and climatic extremes make these arid and semi-arid regions very dependent on careful and conservative water management. Traditional practices that use only gravity to distribute water in these environments have been used for thousands of years, but have been little studied and are under-appreciated. These gravity-based canal systems are known as acequia (Spanish) and secondary and lateral ditches are called laterales, linderos, sangrias, or venitas. The head gates that divide and control water flow are called compuertas. The workers who build and maintain these systems are known as acequieros.
Acequias are called séquia (Catalan), acéquia (Portugese) and saia (Sicilian). The common name acequia is from the Arabic as-saqiya, meaning water conduit. Adapted from the Yemeni-Sabean language, predating the Arab arrival. In Yemen these irrigation systems are now called ma’aayeen. In Oman they are falaj, in Arabic literally ‘to divide.’
For thousands of years acequias have relied on the force of gravity for the collection, conduction, distribution, recollection, and discharge of water in farming systems. This sophisticated community-based irrigation was brought to Spain by farm families arriving from the Arabian Peninsula (Yemen, Oman, Syria and Egypt).[i] The antecedents also included the irrigation practices used in other arid regions of the Roman Empire.[ii]
The acequias were adopted and refined in southern Spain, particularly Andalusia, Castilla, and Valencia during the Moorish occupation[iii] and brought to the Americas in the 1500s. The key factors are gravity flow and community management. Many acequias are still in use around the world including the United States (particularly in Colorado, New Mexico, Arizona and Texas), Spain, Mexico, Ecuador, Argentina, Peru, Madeira Islands, India, Iran (Persia), North Africa, Bolivia, and no doubt, other places.[iv]
In the American Southwest the first acequias were built by Spanish settlers in 1598 near the junction of the Rio Chama and Rio Grande[v] and some ditches still in use today may have first been dug and used 400 years ago.
This region still has many active acequias. Acequia techniques and irrigation methods employed by the Hispanic settlers in this area were also shaped by what they saw in traditional native practices.[vi]
The Hohokam (300 BCE–1450 CE) were gone by the time the Spanish arrived, but the remains of their irrigation systems were still visible. They consisted of main canals, distribution canals, and field laterals. The Hohokam built more than 483 kilometers of major canals and over 1,126 km of distribution canals.[vii] We don’t know how these ditches were organized and managed but may well have been community based–like the acequias. The Anasazi (1000BCE–1300CE ) had also developed complex irrigation systems using gravity flow. The Pueblo, Tohono O’odham, Hopi and other first nations people of the Southwest were also actively managing water systems when the Spanish arrived.
The many acequias operate in similar ways but differences in soils, topography, environment, history, geography, climate, culture, regional and national setting, and language make each one unique.[viii] They share common attributes including: autonomy, turn-taking, equity in work for water distribution, uniformity, transparency, boundary maintenance, direct feedback, and graduated sanctions.[ix]
Over the centuries, acequias have overcome periodic cultural and environmental crises, rivalries with other types of water users, and profound historical changes. They have survived because they are community based and because they worked. Once constructed, the local acequia de común (commons ditch) created a community of interest and connection.[x] The bio and cultural diversity in acequia communities also helps with the critical factor of resilience – the ability to recover from perturbation and adversity.[xi] The community of sharing provides insurance against the challenges of drought, floods, and changing power relations.
Some of the most robust acequias are found in Spain and New Mexico. In Spain 550 irrigation communities in Granada and Almeria have over 24,000 km of acequias. More could be restored. A bigger investment in restoration could bring climate, environmental and social benefits to many.[xii] In New Mexico as many as 700 acequias still remain in use, providing irrigation water to about 160,000 acres on 12,000 small family sustenance farms, some dating from the sixteenth century.[xiii] There have been enough activists, lawyers, and receptive politicians to protect the acequias from at least some of the threats that can cause their failure.
In some cases the acequias operate as autonomous common property regimes and also are legal subdivisions of the state, subject to state statute.[xiv] An acequia association typically consists of farmer-rancher members and landowners who share a common stream diversion into a hand-dug “mother ditch” with laterals channeling water to individual properties.[xv] Members are obligated to pay dues, contribute labor to the cleaning and maintenance of acequia infrastructure, observe the customary principles of water sharing, and annually elect a ditch boss (mayordomo) or el digno de confianza—the one who is worthy of trust) and commissioners[xvi] (often 3) who oversee ditch operation and governance. Labor demands are proportional to the amount of acreage or shares a member irrigates. A member may have to pay for a laborer to do his work if he cannot. The mayordomo allocates water proportionally to members in good standing and resolves disputes over water. The mayordomo may ride along the entire ditch to oversee diversions. The mayordomo can face critics and anger when droughts limit water supply. As flows drop a farmer may only get a water allocation every two weeks or less.
How do they work?
Water is diverted from a creek or river with a diversion dam that might be permanent or rebuilt every year. These could be solid or made of brush and porous. The design of the ditches, laterals and fields was critical. Too much slope and the flow would erode the channel network and the farmland, while too little slope would limit the water flow and allocation. Head-gates control the flow for each main ditch. Periodic laterals are linked with more gates.
Some laterals on the mother ditch are placed in areas where they can help reduce damage from overflow during minor floods and opened wide to help flush sediment. Water seeps out under the earthen walls and helps recharge groundwater. It also supports riparian growth. The flow of water may be split or redirected by a series of gates[xvii] before it reaches the farm. Each member will have a small diversion gate (or several gates) to bring water onto their land. Today the diversion might be done with a permanent gate, stones, or a sheet of plastic or metal that can be set to release or block the flow of water from the ditch.
Acequia managers have to be flexible.[xviii] In a dry year with little water available, the acequia mayordomo and commissioners were stressed but often able to keep the ecosystem alive and provide critically needed water for crops. During wet years, they might expand the community’s irrigated footprint. Acequieros were kept busy during storms watching areas known to be at risk. A shovel full of dirt in the right place could prevent a disaster.
Maintenance
Yearly communal maintenance of the irrigation works was crucial to avoid decreased performance or even the collapse of the acequia.[xix] The work might be managed by the mayordromo or a key worker, in line with customary uses, rules, and regulations of the acequia. In the winter the ditches were dry and more serious repairs could be made. Spring cleaning would clear silt deposits, vegetation growth, fill animal burrows and stabilize the earthen channels.
“We’ll clean out anything that’s encroaching onto the lining, take out any kind of sediment, take out everything that’s going to impede on getting proper flow in the ditches,” says Daryl Lucero, one of the hundreds of Jemez Pueblo men who gather every spring for a two-day cleanup, equipped with shovels and axes.[xx] Weeding was important and fire could be used to clear vegetation. Leaks and slumps had to be repaired and corrected. Gates needed attention as well and might have to be reset, oiled and braced. These work parties were not grim, but often lively and provided a chance for neighbors to get together.
Flash floods could breach acequias and deposit sediment. Repairs would need to be made quickly to re-establish flow to the crops. This could require hours or days of labor from many acequieros. Members also kept an eye out to prevent and punish water theft or other problematic behavior. A ditch rider might be tasked with reviewing water use and the condition of the ditches, gates and users. Major repairs would be done in the winter when the ditches were dry.
Community building
Acequias are social institutions and formed the basis of some of the earliest cooperative community government.[xxi] They continue today as models of sustainable agriculture and of community cooperation.[xxii] They depend on the commitment and ongoing interaction of a critical number of members who irrigate, pay their dues, contribute labor, come to meetings, and share water as needed. Members may also need to negotiate conflicts over water use and other ditch matters They might be required to take a turn as a mayordromo or commissioner.
The importance and value of community and cooperation have received surprisingly little attention in resource management. Farm scale research has too often neglected small farms and the opportunities for community and regional development and sustainability. Yet without community building most reforms are unlikely to spread or to survive. Using traditional resource management practices that build community can be a good way to restore a sense of community.[xxiii] can bring isolated farmers and land managers together.[xxiv]
If small community cohesion declines the traditional management of the acequia system can collapse. In Mayordomo, a book on a year on a ditch, the old-timers were already grousing that young people were too lazy to run the acequias.[xxv] Still, the acequias have endured. As Crawford notes, “Acequias have survived disruptions of language and culture how many times over hundreds of years?” he asks. “Three times at least. I think they’ve got a built-in mechanism for survival.”
Ecosystem services
Acequias also provide other valuable services including groundwater recharge and ecosystem enrichment.[xxvi] Traditional unlined acequias and side ditches add water to the ecosystem by seepage and leakage. In New Mexico the water budget of the Acequia de Alcalde was analyzed. During the three-year period of the study, over half of the water diverted into the acequia returned to the river relatively quickly as surface water.[xxvii] More water than is needed for irrigation is driven through the acequia to provide sufficient flow to reach the end of the ditch with enough water to irrigate.
Other studies have shown that seepage can range between one-third and one-half of the flow.[xxviii] In Spain the flow of water in the Spring may be diverted to areas known as simas.[xxix] This water seeps into the ground and is known locally as “sowing water.” The acequia that supplies the village of Mecina-Bombarón sows water until the end of June most years. This recharges the groundwater and supports the flow of springs and streams. The acequias of the Sierra Nevada (Spain) have been recharging the underground aquifers for more than a thousand years.
Placing samis over Paleo-valleys would improve storage and speed water capture.[xxx] The best sites can be identified by airborne electromagnetic (AEM) mapping of groundwater basins.[xxxi] This has been done in California, New Mexico, Arizona, Australia and other countries. The catalyst for these studies in California was a groundbreaking study showing (AEM) surveys could detect the subterranean paleo valleys that can absorb as much as 60 percent more water than adjacent clay soil areas. Services are now available in the US.[xxxii]
Seepage from the acequia system allows a complex mix of vegetation and organisms to develop. The edge of acequias may mimic riparian ecosystems and cienagas. Some species are deliberately planted to help stabilize the ditch walls. Other plants seed themselves from nearby habitat or drift down the acequia. The lines of trees along acequias can be effective corridors and habitat for wildlife, much like fence rows.[xxxiii] On the family homestead in SW Colorado the small ditch that cut across our land supported wildlife including muskrats, beaver, fish, ducks, other birds, and many other species. Asparagus also sprouted along the ditch and was harvested.
The future and present
In many areas the acequias are the life of the village. Without them the farms would be dry and communities would die. Though ancient, this traditional water management system is sustainable, efficient and resilient. Rules, regulations and practices differ around the world and current and future challenges vary. Climate change poses a great challenge for small farmers around the world and in some cases acequias can help manage water efficiently. In many area creating acequias could help communities survive on-coming changes.
Legislation, lawsuits, education and investment can help acequias prosper. New Mexico has a very long history of use and their acequias communities have been effective in moving legislation to protect their status. This began in 1846 when New Mexico was claimed as a territory by General Stephen Watts Kearny.[xxxiv] In 1848 the Treaty of Guadalupe Hidalgo pledged that property of every kind would be inviolably protected and this included the acequias. By the end of the 19th Century acequias had been recognized as quasi-public corporate entities and in 1907 the Acequia Act defined mayordromo and commission members rules, elections and responsibilities. Struggles have continued over water and land, but rights and status were clarified in new laws in 1978, 1987 and 2009. In 1987 the governor created the New Mexico Acequia Commission and in 1993 this was established by statute as an eleven member commission serving four-year terms.
In Spain a project was established by the Laboratory of Biocultural Archaeology at the University of Granada in 2014 to restore abandoned acequias and recover the flow of water, and traditional ecological knowledge.[xxxv] The Memolab project has restored 14 acequias and cleaned 30 others.
While the project’s primary objective is to restore acequias, it’s also a social intervention, says project coordinator José María Martín Civantos, an archaeology professor at the university. The project also hoped to improve the governance of the community, to empower the community, to revitalize the communities, and to recover knowledge and practices.[xxxvi]
In the United States The Water Resources Development Act of 1986 recognized Acequia Irrigation Systems and authorized measures to protect and restore them. This act led to the US Army Corps of Engineers Acequia Restoration and Rehabilitation Program. Upgrades often include concrete lining, this saves water but reduces the ecosystem benefits.
Climate Change and the Way Forward
Climate change adds both new challenges and greater potential value for acequias. Longer, more severe droughts are expected.[xxxvii] As Caitriana Steele, an associate professor at New Mexico State University put it, “The acequia communities, they’re right on the frontline of these changes.”[xxxviii] Rising temperatures are causing the water from snowmelt to arrive earlier in the spring. This complicates irrigation management and can mean depleted flows in the summer, when the demand for water is highest. Adopting the use of simas may help cope with these changes by storing more water in the soil.
Bottom Line
Gravity-based irrigation with acequias is sustainable, ecological and economic, but it takes a community to make it work. Acequias are proven, traditionally-managed water systems that can be designed, built and maintained by local people. These elegant systems were neglected by researchers and policy makers until rcently,[xxxix] but when the electricity is out and the pumps fail their value is clear. It is time to rediscover, restore and expand the use of these marvelous water systems and other ancient, proven water management systems.[xl]
Video
Acequias: The Legacy Lives On is a fifty-six minute and forty-six second visually stunning documentary film about New Mexico’s enduring acequias as seen through the eyes of farmers, advocates, scholars, practitioners, and members of the community.
References
[i] Martín Civanto, J. M. Cultivating water in an age of climate change. Lapilli. Magma. https://www.magma-mag.net/cultivating-water-in-an-age-of-climate-change-2/ Accessed Feb. 6, 2025.
[ii] Ortloff, C. R. Roman hydraulic engineering. pp. 171–194. In Ortloff, C. R. ed. Water Engineering in Ancient Societies. MDPI Switzerland. (2022)
[iii] Walker, K. The Moorish invention that tamed Spain’s mountains. BBC, October 11. (2022).
[iv] Atenciom, E. Acequia Waters. Taos acequias.org (2025)
[v] Rivera, J. A., Arellano, J. E., Lamadrid, E. R., Martinez, T. Irrigation and Society in the Upper Río Grande Basin, U.S.A: A Heritage of Mutualism. University of New Mexico. 15 p. (2014)
[vi] Many irrigation companies in the SW developed similar management practices but were private, perhaps with an individual or group owning shares. Many experienced repeated failures and bankruptcies.
[vii] Mays, L. W. Ancient Water Technologies. Springer. (2010)
[viii] Rivera, J. A. and Lamadrid, E. R. Water for the People: The Acequia Heritage of New Mexico in a Global Context. University of New Mexico Press. (2023)
[ix] Trawick, P., Reig, M. O. and Salvador, G. P. Encounters with the moral economy of water: Convergent evolution in Valencia. WIREs Water. 1:87–110. (2014)
[x] Rivera, J. A. The roots of community in the Northern Rio Grande: Acequia mutualism, cultural endurance, and resilience. p 13. in NMSU2020.
[xi] Holling, C. S., Gunderson, L. H. and Allen, C. R. Foundations of Ecological Resilience. Island Press. (2009)
[xii] Walker, K. op. cit.
[xiii] US Army Corps of Engineers Albuquerque District. Acequia Rehabilitation and Restoration Program. https://www.spa.usace.army.mil/Missions/Civil-Works/Acequia-Program/
[xiv] Buynak, B., Widdison, J., Bushnell, D. Acequias. Water Matters 4:1-20. (2013 [2007])
[xv] Rodriguez, S. Key Concepts for a Multidisciplinary Approach to Acequias. p 6. in (NMSU2020)
[xvi] Neuwirth, R. Centuries-old irrigation system shows how to manage scarce water. National Geographic. May 17. (2019) https://www.nationalgeographic.com/environment/article/acequias
[xvii] On a research plot I used in Riverside, California it took two valves and a gate and a considerable walk to get water from the ditch to the field.
[xviii] Mayagoitia, L., Hurd, B., Rivera, J., and Guldan, S. Rural Community perspectives on preparedness and adaptation to climate-change and demographic pressure. Journal of Contemporary Water Research & Education. 147:49-62. (2012)
[xix] Davanzo, D. Framing the Spring Ritual of la limpia. pp. 29-37 in Rivera, J. A. and Lamadrid, E. R. Water for the People (2023)
[xx] Roedel, K. A New Mexico Pueblo’s antiquated irrigation system is being tested by drought, wildfires. KUNR Public Radio, May 11. (2023)
[xxi] Atencio, E. Taos Acequias Association
[xxii] Rodriguez, S. Acequia: Water Sharing, Sanctity and Place. School for Advanced Research. Santa Fe.
[xxiii] Rivera, J. A. Acequia Culture: Water, Land and Community in the Southwest. University of NM Press, Albuquerque. (1998)
[xxiv] Bainbridge, D. A., Steen, A. and B., Eisenberg, D. The Straw Bale House. Chelsea Green. (1994).
[xxv] Crawford, S. Mayordomo. University of New Mexico Press. (1993)
[xxvi] Fernald, A. G., Baker, T. T. and Guldan, S. J. Hydrologic, riparian, and agroecosystem functions of traditional acequia irrigation systems. Journal of Sustainable Agriculture 30(2):147-171. (2007)
[xxvii] Ochoa, C. G., Guldan, S. J., and Fernald, S. Surface water and groundwater interactions in acequia systems of Northern New Mexico p36 in (NMSU2020)
[xxviii] Neuwirth, R. Centuries-old irrigation system shows how to manage scarce water. National Geographic. May 17. (2019) https://www.nationalgeographic.com/environment/article/acequias
[xxix] Walker, K. op. cit..
[xxx] Gies, E. 2022. Capturing the flood in California’s ancient underground waterways. Bay Nature. January 4. (2022)
[xxxi] Cahill, N. High tech mapping of Central Valley’s underground blazes path to drought resiliency. Western Water. June 1 (2023)
[xxxii] Collier Geophysics. https://colliergeophysics.com/airborne-geophysics/
[xxxiii] Montgomery, I., Caruso, T. and Reid, N. Hedgerows as ecosystems: service delivery, management, and restoration. Annual Review of Ecology, Evolution, and Systematics. 51:81–102. (2020)
[xxxiv] Buynak et al. op. cit.
[xxxv] Walker, K. op. cit.
[xxxvi] Bocanegra, E. Restoring water channels from the days of Al-Andalus to irrigate modern Spain. El Pais. January 6. (2022)
[xxxvii] Chen, L., Brun P., Buri P. et al. Global increase in the occurrence and impact of multiyear droughts. Science. Jan 17;387(6731):278–284. (2025)
[xxxviii] Medrano, L. Can New Mexico’s Ancient Water System Survive Climate Change? Undark. 10.09. (2024). https://undark.org/2024/10/09/new-mexico-ancient-water-system-survive-climate-change/
[xxxix] Google search “acequia research paper” 68,000 hits, “drip irrigation research papers 4 million
[xl] See for example Bainbridge, D. A. Qanats. EcoMENA. (2025); Bainbridge, D. A. Stepwells. EcoMENA (2024),
Bainbridge, D. A. Gardening with Less Water.
Bainbridge, D. A. Buried clay pot irrigation. Agricultural Water Management. 48(2):79-88. (2001)
