By definition, water scarcity is the central challenge of sustaining life in arid lands. It’s easy to forget how large that challenge is: Arid and semi-arid lands make up one-third of the earth’s land surface and over one-third of the continental United States. The 20th-century American effort to provide water to these lands in the name of social progress and economic growth has given rise to some of the most spectacular civil engineering feats in history, and has served as one model for water systems internationally.
In the century that followed the 1902 Newlands Reclamation Act, the engineers of the American West constructed a 500,000-square-mile watershed designed to do two things — deliver us snowmelt and rid us of stormwater. The engineering (and ideological) paradigm behind this synthetic watershed is stationarity: the notion that systems fluctuate within an unchanging envelope that can be described, modeled and predicted. Predicated on a constant supply of political will, financial capital, cheap energy and Holocene hydrology, the American system is designed to flatten topography, culture and time.
The photographs of 20th-century structures presented in the first half of this slideshow constitute a contemporary archaeology of the architecture of stationarity.
That system is now nearly obsolete. Its infrastructures have accelerated and exacerbated the largest and least understood environmental challenge of the 21st century: water is changing. It takes a lot of energy to transport snowmelt across deserts to agricultural and urban centers; likewise, in a negative feedback loop, it takes a lot of water to produce that energy. The carbon-intensive fuels used to deliver western water — mostly coal and natural gas — contribute to a warming climate that is reallocating the hydrologic cycle. Projected climate impacts in the Western United States include longer droughts, less snowpack and more intensive rain events.
Intelligent water solutions will break western water’s reliance on carbon-intensive energy for long-distance transport, and will look again to localized systems and reposition the hydrographic basin as the basic unit of durable occupation. In both urban and rural centers, a healthy Anthropocene will see a de-industrialization of water systems, an insurgence of adaptive alternatives and a design reckoning with a new paradigm of variability that replaces the assumption of stationarity.
Our exploration of the engineered surfaces of the West, industrial and pre-industrial, has led us to consider alternative models of irrigation societies — some archaeological, some historical, some contemporary — that operate outside the predominant American model and offer promising possibilities for re-imagining hydrologic urbanisms and architectures.
Examples of adaptive technologies and robust settlement patterns that we have photographed along the Lower Colorado River and the Upper Rio Grande include:
- ancient flood-plain irrigation techniques employed along Arizona’s Salt and Gila rivers by the Hohokam, a society of sophisticated engineers whose culture dispersed when monumental water infrastructures no longer operated effectively in the face of long-term drought;
- contemporary flood-plain irrigation practices on the Gila River, where the Tohono O’odham, descendants of the Hohokam, have adopted water management and planting strategies that incorporate mobility, velocity and ephemerality as concepts critical to sustaining life under extremely variable conditions;
- run-off irrigation landforms that have shaped the surface of Chacoan culture, including archaeological evidence of ancient dam sites, reservoir basins and irrigation canals; as well as contemporary systems of mesa run-off and gravity-fed outliers in continuous use for the last 1,000 years;
- Spanish colonial-era acequia communities, or “water democracies,” of northern New Mexico, where irrigation practices of Roman, Arab and North African origin were transplanted to New Spain in the late 1500s and are still practiced today, sustaining shocking levels of ethnic, linguistic and biological diversity;
- 19th-century Mormon irrigation districts from Southern Utah to Northern Arizona, where carefully planned water and land use (not only a shared theology) underpinned a collaborative urbanism.
These photographs remind us of the wide terrain of innovation written into the surfaces of the West, a record of adaptive design that transcends the 20th-century presumption of indefinite abundance.