Southwest's earliest known irrigation system discovered

Los Angeles, May 25 (ANI): While preparing for the expansion of a Tucson wastewater treatment, US archaeologists have discovered the remains of the earliest known irrigation system in the Southwest, a farming community that dates to at least 1200 BC.

The discovery has indicated that the inhabitants of the region began with relatively simple irrigation systems, and advanced towards more complex projects as the climate became hotter and drier.

"These are not the earliest canals known in southern Arizona, but they are the most extensive and sophisticated engineering [from the period] that we have identified to date," the Los Angeles Times quoted archaeologist James M. Vint, of Desert Archaeology Inc. in Tucson, as saying.

Located at the confluence of Canada del Oro, Rillito Creek and the Santa Cruz River, the site, called Las Capas, or "The Layers", derives its name from the repeated layers of silt that buried the site until nothing was visible from the surface.

Vint led a team of 30 archaeologists who explored the site, while keeping up with the state laws, before they started working on a planned expansion of the Ina Road facility.

"We put in a mile and a half of backhoe trenches and did archaeology in all those trenches. That tells us this is a very expansive site," he said in a telephone interview.

The archaeologists identified two main canals bringing water from the Santa Cruz River and feeding it into eight distribution canals, all now buried 3 to 7 feet.

Vint estimated that the system could have irrigated 60 to 100 acres.

The primary crops were maize, which was introduced into the area before 2100 BC, and an herb known as amaranth.

The evidence revealed that the region suffered a huge flood about 800 BC, which buried the canal system.

Vint said: "There is some evidence that they tried getting it going again, but apparently that didn't work. They cleaned out some sections, but they never brought it back to full scale." (ANI)