Exploring Life at the Edge

The City of Phoenix lies in the northern portion of the Sonoran Desert, one of the most beautiful and distinctive places on Earth. Within the urban environs, however, a person would be hard pressed to find much evidence of the desert. Indeed, in an informal poll conducted by tour guides from the Desert Botanical Garden in Phoenix, local school groups routinely are asked the question, “Do you live in the Sonoran Desert?” Astonishingly, few children raise their hands.

This lack of awareness can be blamed, in part, on a failure of design, says Joe Ewan, ASU assistant professor of landscape architecture. Although Phoenix boasts an extraordinary legacy of desert mountain preserves, including South Mountain, the largest municipal park in the country, the Sonoran Desert is poorly integrated into the daily fabric of urban life.

Ewan says that landscape planners need look no further than places like Ahwatukee, a community that borders the southern edge of South Mountain. Nearly 11 miles of more or less continuous concrete-wall fencing separates the desert’s creosote, cactus and coyotes from the backyards of private homes.

Critics have complained that such hard boundaries restrict public access to the city’s open spaces. And biologists caution that they artificially isolate plants and animals, threatening their survival over the long term.

Ewan got back to work before the ink was dry on his award-winning master plan for a major new preserve on the northern outskirts of Phoenix. Working with ASU architecture professor Michael Underhill, Ewan explored the problem of the urban-wild edge. The project included a graduate class composed of architecture, planning, and landscape architecture students.

In May 2003, Ewan and Underhill published “Exploration of the Edge,” a study of the ways in which the new Sonoran Preserve can be better integrated into the human-built environment.

Adapting concepts from the study, Phoenix officials recently drafted a set of prescriptions for development along the new preserve known as the Sonoran Preserve Edge Treatment Guidelines. Chief among the document’s goals were provisions to create a more porous edge along the urban-wild interface. To accomplish that goal, for example, developers must leave 60 percent of the land adjacent to the preserve as open space.

Developers also are encouraged to treat concerns about public access in novel ways. They should create pedestrian-friendly neighborhoods adjacent to the desert or small commercial nodes where visitors can congregate along the desert’s perimeter on constructed promenades known as paseos. Such new uses are designed to take some of the frustration out of visiting the mountain preserves.

Ewan explains. “For example, right now you can get into your car and drive to a place like Camelback Mountain. Once there, you struggle to find a parking spot if the weather is nice.

“So, you end up parking on some residential street somewhere. You walk through cars and traffic just to get to the trail,” he continues. “Once on the trail you have a wonderful experience. Perhaps you see people you know and stop to have a conversation. But when the hike is complete, you again must walk through traffic just to get to your car. Maybe you stop for a bagel or coffee at a strip mall where you sit on a patio and stare at a sea of cars. Perhaps you even see the same people you saw on the trail. It seems absurd that these things are so disjointed,” Ewan says. “We saw the lack of interface between these two types of uses as one of the great missed opportunities.”

Above all, Ewan hopes the new guidelines will encourage the most important public access of all—the exposure of future generations of children to the natural environment in which they live. Pointing out how much the future survival of a healthy desert depends on an ecologically literate citizenry, he champions the idea of locating schools on the desert’s edge.

“We need to learn how to live with the desert,” Ewan says. “The ability of a generation of Phoenicians to be educated with daily access to this type of natural open space is truly incredible.”—Adelheid Fischer

Editor's note: In October 2003, The Phoenix City Council unanimously passed the Sonoran Preserve Edge Treatment Guidelines. In the same month, the American Society of Landscape Architects named Joe Ewan as their Educator of the Year. The Arizona ASLA chapter also recognized Ewan and Michael Underhill’s “Exploration of the Edge” project with an Honor Award.