Water Resources: A Documentation of Water Technologies in the Atacama Desert | Catherine Ann Somerville Venart

The Atacama is a Desert region stretching from Peru’s southern border into northern Chile. In Chile this region is known as San Pedro de Atacama and is designated the driest desert on earth. These areas are known as “absolute desert,” so arid that little or no life can exist within them. The altitude and topography together with the presence of water determine to a large extent what areas humans and various species of plants and wildlife can survive within. In most cases it is the ability of a species to adapt to the severity of the environment that determines its success or failure. The balance between an ecosystem and a species, how many it can support and where they inhabit is a negotiated, cause and effect relationship between a species and its environment. Some adaptations are cultural learnings or based in experience, some are biological and some occur within the environment itself, due to the inhabitation of it. For example, the burrowing of animals in the earth, is similar to early dwellings, which are dug in and made of thick earth walls, both use the earth for its insular properties. The lizard skins scales, are a biological adaption, where small pockets created by the scales enables water to collect, within the surface of the skin. This surface modification is similar to the agricultural plots or Chacras or Hoyas [1], which are shallow excavations that create subtle shifts in topography where moisture for their crops collect due to temperature differential between night and day. All these adaptions to “place” enable plant, animal, and human beings to dwell within a given landscape. This direct knowledge has come about from centuries of understanding of the earth and its resources as well as observing the plants and animals that also inhabit it. In the small oasis villages and towns in this region, some of this knowledge is still being utilized. So, in the face of rapid change, the question is how to keep this knowledge of the earth and its resources alive; and yet be able to adapt, grow and develop without threatening ecosystems and causing desertification.

The region’s main geographical zones are: (1) the coastal zone, which is the most densely populated area in the region; from this narrow coastal ribbon, the land rises steeply through the (2) Andean foothills (precordillera) to (3) the Pampas. These dry lifeless plains cut by river gorges, rich in mineral sediments from the Andes and (4) alluvial saltpan basins, of which the Salar de Atacama is the largest in Chile. A series of (5) high altitude plains, or sub-desert grasslands, continue east to (6) the Andes (cordillera) with their snow-covered volcanoes reaching upwards of 6,000 meters above sea level. This extreme climate and the vast and impressive scalar dimensions of its landscape have a direct and profound effect on understanding of the temporality and fragility of our existence, and indeed any existence within it. The tenuousness of human beings’ ability to survive within this landscape is observed first in the scarcity of vegetation; the extreme temperature differences between sunrise and sun set; and in the elaborate systems of gathering, directing and holding water.


Figure 2: Map of the Salar de Atacama Basin

The present study will concentrate on the area directly east of the Salar de Atacama (Fig.2), where several oasis towns are located. It documents two methods for gathering and distributing water, tracing water from its origins to use in (1) the town of Socaire, whose agricultural fields are fed by seepage water and (2) the small oasis town of Toconao that uses water from a deep river gorge. Both towns utilize ancient water systems today.

In this area, all water from the altiplano or high altitude plains and the Andean mountains, including river gorges, seepage water and mountain run off or snowmelt, makes its way to the Salar de Atacama basin. There is no outflow of water into any other water basin or to the sea, making the Salar de Atacama basin a closed system, with water leaving the system only by evaporation or through use by plants, wildlife or humans. Therefore, any water extraction will have direct consequences on the ecosystems involved, both currently and in its future.

Figure 3: Irrigation System that transfers water from source to field via human made canals, ditches and diversion walls.

In the town of Socaire (Fig. 3 & 4) small scale agricultural practices, consisting of a pre-Hispanic patterning of small irregular-shaped chacras or holdings that use a communal irrigation system to grow alfalfa, vegetables, and cereals. Field techniques of terracing or excavation, and shallow sloped fields or patches, called hoyas, create pockets of moisture and warmth that protect and nourish the crops, and enable them to be less dependent on irrigation water. Complementary irrigation helps to accelerate the time the crop takes to mature. This system is created using ditches or canals, the edges of which are reinforced by building up using either earth walls or stones, and sometimes mortar or concrete. Each field receives water through a gravitational system that uses subtle slopes along a central canal fed from an up-hill source controlled by a water gate opened to irrigate the top edge of each sloped field. The size of the settlement makes the use of irrigation techniques vital to the quantity and quality of crops. Thus, settlements are dependent on channeling water from snowmelt streams or seepage run-off, and therefore must address issues of climate change as well as water management if they are to survive. The challenge then is to find methods of collecting and using water to maximize its usage, satisfying development needs without strong or possibly irreversible impact on the natural systems.[2]

Figure 4: Photos’ Documenting Irrigation Fields and Field techniques in Socaire, Chile.

The town of Toconao (Fig. 5) is an oasis ecosystem. Its primary water source is the deep river gorge of the Rio del Valle de Jere that cuts through the desert plain on route to the Salar basin. The town’s water infrastructure is an elaborate system of canals and earthen walled reservoirs, with water gates that control the water levels and the distribution of water to the town as well as the fountain in the main square.  Changes in water availability and land use can make the town and its ecosystem vulnerable. Changes to the demand being put on the system are very real as increases in population due to mining, tourism, and the large international teams of astronomers that come to observe the clear skies found in the arid atmosphere of the Atacama Desert make these issues imperative to address. These changes have already begun in many communities in this region, shifting their economies from agriculture and livestock to construction, mining and tourism. As seen in the town of San Pedro, this has occurred very quickly, where agricultural lands have been developed for tourism projects (hotels, resorts and expedition companies, etc.) instead of remaining agricultural lands. This comes about when agriculture and the “land” have no more cultural value. There are many ramifications, especially here,within a closed system, as it creates a system where a scarce and limited resource is traded for a “monetary” income that depends on sources outside the system for survival.  This disconnects the inhabitants from the earth and the knowledge held within working and living with the land. This break in the continuity of knowledge creates a loss of cultural understanding and the direct understanding of “place.”

Figure 5: Photos’ Documenting Water Infrastructure in Toconao, Chile.

In the late 1990’s the government of Chile passed the “Indigenous Law,” one that recognizes the indigenous peoples of this region, and titled this region the Atacama La Grande Indigenous Development Area. This has given “the Atacameños greater control over their ancestral lands and the use of public funds,” it combines a “concentration of government development initiatives,” with “large scale mining, an emerging tourism industry and globally relevant astronomy projects,” and creates a unique and difficult challenge for this region and its peoples. “There is a need to connect traditional activities of production (agriculture, livestock, craftwork) with tourism and the [larger] economy through diversification and technology development.”[3]

With an increasing demand being put on the water supplies of this region and the current practices of land use and water management, the gap of understanding the interconnectivity between ecosystem, development, and us will only widen. We need to acknowledge the cultural importance of this connection to the earth and an understanding of our place in it, recognizing indigenous knowledge, a knowledge that has enabled settlements to lived in harmony with other natural habitats and ecosystems for centuries. We also need to recognize that these same sets of knowledge need to adapt, such that the cause and effect of the larger scale of the natural systems (hydrological and ecological) as well as the localized sites of human settlements, are tested to see the effects of the local on the larger whole. The problem that is put to these communities, then, is two-fold: what are the limits to growth, i.e. “how much development can be sustained,” and how can we keep both ecosystems and hydrological systems in balance with development, so that “we” remain within the realities of “place?”

All images © 2013 Catherine Ann Somerville Venart.

[1] Denevan, William. Cultivated Landscapes of Native Amazonia & the Andes, Oxford UK, Oxford Geographical & Environmental Studies, 2001.
[2] Beatriz Bustos, G. & Hernán Blanco, P. “Patta hoiri and Likanantay people: rescuing the knowledge of the land”, RIDES (2005). Santiago, Chile pp. 8, 11-14.
[3] RIDES (2005). Bienestar humano y manejo sustentable en San Pedro de Atacama, Chile–Resumen Ejecutivo (Human well-being and sustainable management in San Pedro de Atacama, Chile–Executive Summary), Santiago, Chile: RIDES. Santiago, March 2005 RIDES (2005). p. 36.

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