The desert people who built a US city

The 180 miles of canals that criss-cross Phoenix, Arizona, allow millions of people to live in the sun-baked desert. But most people don’t know the story of their mysterious origins.

Crisscrossing Phoenix, Arizona, are 180 miles of canals – more than twice as many as Venice and Amsterdam combined. As a native Phoenician, I’ve spent many hours bicycling their banks alongside joggers and fishermen casting for carp. I’ve joined wildlife watchers strolling the main Arizona Canal on a summer evening to watch Mexican free-tailed bats make a mass fluttering exodus from their roost. And I’ve chatted with long-time residents who fondly recall fashioning water skis from plywood, tying a tow rope to a pickup truck and jetting through their neighbourhoods in a spray of water and dust.

The canals deliver irrigation and drinking water throughout the metro area, allowing millions of people to live in this sun-baked desert. They are a major reason Phoenix exists, and the city’s name hints at their mysterious origins.

In 1867, the city’s founding father, Jack Swilling – a prospector who had fought on both sides of the Civil War – stood above the Salt River Valley and saw the remnants of irrigation channels squiggling across the landscape like stretchmarks. He realised that, centuries before, some society had farmed this desert. Soon after, Swilling began scouring out the debris-clogged ditches to bring agriculture back to the region.

Three years later, Swilling and other Anglo pioneers met to consider names for their settlement. The top contenders were Pumpkinville and Stonewall. Luckily, eccentric English adventurer “Lord” Darrell Duppa proposed a name inspired by the resurrection of the canals. “A great race once dwelt here, and another great race will dwell here in the future,” he mused. “I prophesy that a new city will spring, phoenix-like, from the ruins and ashes of the old.”

That great society was the Hohokam. Between 100 and 1450 CE, they constructed 1,000 miles of canals – the largest system of waterways in the Americas north of Peru. This sophisticated irrigation system harnessed river water and a meagre seven inches of annual rainfall and funnelled it to more than 100,000 acres of farmland. And they dug it all by hand with stones and sticks.

“The engineering is phenomenal,” said Kathy Henderson, principal investigator at Desert Archaeology, an Arizona-based cultural resources management and research company. “We don’t see a sequence where they start small. The canals are being built to scale as early as 500 or 600 [CE]. They must have been very attuned to how to transport water a long distance.”

For Gary Huckleberry, a geologist and adjunct researcher at the University of Arizona, the water-wise Hohokam and their ancestors are still relevant today. “In the Southwest, we have some serious issues to deal with in terms of water,” he said. “The Colorado River is the main source of water for the Southwest, and it’s over allocated. You’ve got population growth and climate change. How are we going to deal with that? I think there’s something to be learned by looking at past societies who managed water for thousands of years.”

Native Americans have been building canals in Arizona for at least 3,500 years. The oldest waterways archaeologists have found date to 1500 BCE and diverted water from the Santa Cruz River in Tucson. Through trial and error, these ancient river people accumulated knowledge that was passed down from generation to generation, Huckleberry notes. “So, by the time you get to the Hohokam, they were skilled hydraulic engineers.”

BBC