Acequia Culture
Juan Rivera

notes on presentation, August 31, 2007
SouthWest Water: An Artistic Approach to Preserving Water Quality and Quantity in the American South West.

The first Spanish acequia irrigation ditches go back to 1598, one month after Don Juan de Oñate’s initial conquest of New Mexico. They are based on gravity and dug and built with precision so that gravity flow can carry the water for miles in bermed earthen trenches. Every acequia is unique, because the topography that each one crosses and contributes to, and the river that each one draws from, are all individual. The Spanish brought acequia culture with them from Spain, where they had inherited it from the centuries-long Moorish settlements in Andalusia, but they learned a lot from existing Native American irrigation methods practiced by the Anasazi and Puebloan cultures.

The first Spanish acequia in New Mexico diverted water at the confluence of the Chama and Rio Grande rivers. They were dug to water fields at Chacon, and that acequia still carries the water from the Rio Grande, over a mountain range and down an 800-foot drop (the resulting waterfall is part of the acequia, not previously present in the landscape) into the Chacon valley. Pre-colonization, that water joined the Rio Grande; having been diverted over the mountain, it now joins the Mora River, and thence the Canadian River, and thence the Arkansas River and ultimately the Mississippi River.

The word “acequia” is Spanish for irrigation canal or ditch that diverts water off a river. The word is of Arabic origin, like the practice and culture it names. Diversion dams, source of acequias madres, (the point at which the acequia diverts water from the river) are called “presas.” Irrigation ponds or oasis are called “tanques.” During the Moorish (Arabic) settlement period in Spain, which lasted over 400 years (as long as Rome was in Britain, for comparison) they developed the acequia and flood irrigation systems and methodology. When the Christians reconquered southern Spain and evicted (or forced the cultural assimilation of) the Moors, royal edict declared that the acequia system would not be damaged and would remain in use. It was then expanded on and exported to other parts of Spain and became deeply entrenched (so to speak) in Andalusian culture.

In the American South West, water control systems had been developed long ago by the Anasazi and Pueblo peoples. They used the material at hand in any given bioregion to create their irrigation ditches, rather than importing materials. Local materials included tree trunks and sticks, clay and mud, and basalt rock in what is now northern New Mexico. These irrigation systems moved water through deep trenches long distances to water fields of corn, squash, chiles, tomatoes, potatoes and beans, as well as other native plants. When the Spanish colonized the area, they learned from the Pueblo’s ability to use the material at hand, since importation of specific materials was very difficult, and they worked with whatever was available in much the same way the Pueblos did.

Acequia irrigation was and remains common in areas where the average annual rainfall is less than 13 inches/year, which includes all but the highest elevations in New Mexico and Arizona. In most of this region, the monsoon season, when it comes, provides the heaviest rains of the year in July-September and sometimes into October, but leaves the agriculturally-significant months of May and June scorching hot and dry. This period is the highest use period for acequia irrigation, which uses water from the spring high-altitude snowmelt that is flowing into the rivers. Mayordomos begin to clear out acequias as early as February to prepare for the spring runoff from the sierra watersheds.

The basic principle of the acequia is to raise the riverbed enough to create a diversion channel—not a lake or reservoir. Traditionally, stone and logs were piled into the river to raise the river’s height a couple of feet in a small area, and create a small dam (the diversion dam, or presa), which creates a waterfall. By the side of the waterfall, the diversion water would flow out from the pool this created and into the acequia madre, the source-point of the acequia. From there, the acequia may go on for miles, including many diversion points (“partidoras”) to go many directions, and may include “canoas,” elevated canals of hollowed logs to move the water above the land, such as over a gully or other low spot. “The physics of water served as the principal tool of landscape modification.” Gradual but pervasive landscape change spread out from the acequias, because of the movement of water, lifeblood of the land. This is referred to as “el paisaje de los acequias,” the landscape of the acequias.

The building and maintenance of acequias was and remains communal, but the water rights from acequia water apply to the individual rather than the community. The acequia collects, transports and distributes water for both communal and collective use. Some acequias fed small water-wheel grain mills, “molinas,” for grinding wheat. One of these remains in use in Algodones on special occasions.

In addition, acequia culture includes intangible aspects, such as the knowledge that is passed down concerning skills such as how you move water through the field once it arrives on your land, and how to efficiently and effectively clean the acequia ditches of accumulated debris each spring.

Acequia culture also demonstrates a great rootedness to place—like water, culture extends deep into the earth. It also includes water blessing rituals both Catholic and pagan in nature, including annual blessings of springs, rivers and ditches. San Ysidro is the patron saint of farming.

Ecology and Acequias:

Ecological benefits of acequia watering include:
• Expanding the riparian area and biodiversity by increasing the surface water
• Expanding wildlife habitat
• Preserving native plants as well as cultivars, and feeding taller trees in addition to scrub, allowing further plant diversity in the shade and moister areas thus created
• Aquifer recharge: because almost all acequias are earthen ditches, a great deal of water seeps back into the earth and recharges the aquifer, the same way it does from a naturally-flowing river or stream (this is called return flow). Also, the ultimate destination for the water is a field, where most of the water will seep into the soil to feed plants (except for that lost to evaporation, which is significantly less than in water-spraying irrigation methods that propel the water through the air) and thus return to the aquifer.
• Studies have shown that most of the water rejoins the river in four weeks to three months, not very far from the site of final use, thereby extending the surface-level flow life of the river, which in turn protects and expands wildlife habitat and biodiversity.

Water Claims and Priorities:

• native rights: primary water rights (held in common)
• acequia irritators, pre-1903 (held by individual/family)
• municipalities—formerly only used aquifer water, now also claiming surface water diversion rights on rivers, purchasing acequia rights, to use for drinking water, development, and household use
• industry, which claims “higher economic use”
• recreation & tourism (boating, fishing—State Parks, etc)
• the environment itself: wildlife, riparian area, river flow, species diversity, plant life.

The only place in New Mexico where mayordomos still control the acequia access is in Velarde, where the largest orchards in NM still are. In all other parts of NM, governmental agencies such as the Middle Rio Grande Conservancy District control the water access.

Both acequia irrigators and environmentalists are interested in the preservation of mountain forests and watersheds, as the source of almost all southwest water.

There is an old Spanish farmer’s saying: “When I plant my fields, I throw in four seeds for each plant I want to grow. The first seed is for me, the second seed is for us (our community), the third seed is for god’s creatures, and the fourth is in case the other three fail.”