Designing Water ​Infrastructure ​for the Desert

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Designing Water ​Infrastructure ​for the Desert

With scarce water supplies, a sweltering climate and a rising population, can desert cities such as Tucson and Phoenix sustain us? Three UA experts say they are optimistic.

By Emily Litvack
UA Research, Discovery and Innovation

Can a place where water is hard to come by and heat is hard to escape sustain a growing population?

Some say it can't, insisting that cities have no place in the desert. Given carefully considered and collaboratively conceived water management, urban planning and architecture, University of Arizona experts Sharon Megdal, Ladd Keith and Christopher Domin say otherwise.

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Source: The University of Arizona

Designing for the Desert

Heat mapping can tell you where you need to create more coolness and comfort, but it can't tell you how. Keith's colleague, Christopher Domin, can. Domin is an associate professor of architecture at the UA and the author of a forthcoming book about the life and work of Judith Chafee. He specializes in regional technology.

"As an architect and an educator, I'm thrilled by the lesson the desert provides," Domin says. "If you look at how plants and animals survive in this climate, they can teach humans quite a bit about how to adapt to this ecosystem and transfer those ideas into built environments."

Can an office building, restaurant, school or home not only survive the harshness of the desert, but be sustainable and comfortable for those who inhabit it? Says Domin: Yes, with the right design strategy.

Throughout time, the right design has taken many forms.

Domin points out that, because wood always has been scarce in the desert, people historically have built using earth. The two primary techniques are rammed earth construction — layering mixtures of silt, gravel and a bit of clay — and adobe block construction, in which bricks are made of clay and straw.

"Those materials along with traditional building elements can help us live graciously in this climate," Domin says. "Aside from being abundantly available, these materials allow inhabitants to leverage our high diurnal temperature shift to cool spaces during the day and warm them at night.”

Domin notes that while earth-based construction became much less common in the age of air conditioning, these traditional materials are making a comeback as desert cities reimagine and retool themselves for a future where sustainability is a means for survival.

In 2012, Tucson added amendments to its residential code, deeming uninsulated adobe and rammed earth walls in compliance.

In the 1920s and '30s, people living in Tucson and Phoenix built sleeping porches to stay cool through the night. In the evening, they would migrate to these sleeping porches and hang sheets soaked in water along the sides of the porch.

"This allowed evaporative cooling before the advent of air conditioning," Domin says. "People found ways to live in homes that met the needs of the desert climate."

Even UA dormitories such as Maricopa Hall had built-in sleeping porches at one time.

Advances in air conditioning, along with concrete and other new building materials, allowed desert dwellers to be less deliberate about their habits and routines. Domin says that as we try to return to a more gracious kind of existence, even as the population grows, good design will be considerate of the heat island effect.

It's a kind of calculus, he says: "Create more shade and remove concrete."

Tucson architecture often features distinctly large overhangs (example: Old Main) for the purpose of creating shade, but Domin says well-placed landscaping can create shade, too. Tucson has desert landscaping ordinances for both public and residential projects. The ordinances ensure responsible practices such as efficient irrigation, water harvesting and preservation of native plants.

While architects in the Southwest still rely heavily on materials such as concrete block, Domin talks about options: "Quite often architects design with tough materials to meet the toughness of the Sonoran Desert."

Zinc, he says, is one such example. Zinc roofing and wall cladding is durable, long-lasting and has non-toxic runoff, meaning its effect on the landscape and aquifers is benign.

Architects also can design spaces that keep people cool by considering ventilation and solar angles. A narrower building (say, one room deep) will encourage a breeze to flow throughout, rather than being cut off by interior corridors. Also, placing buildings along the east-west axis, with the longest side of the building facing south, and minimizing western-facing windows, keeps more heat out.

Read full article and watch a video: The University of Arizona

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