Drive across the south end of Scottsdale and you cross land that has been farmland twice. The second time was the twentieth century, when canal water turned it into farms. The first was some eight hundred years earlier, when Hohokam farmers dug canals off the Salt River and led them west across the same flat ground. Almost nothing of the earlier system shows on the surface today. It survives in a 1929 map, a 1990s excavation report, some pottery, and a set of names in the federal gazetteer that nobody seems to have explained.
For the wider story, including Pueblo Grande, the floods and the collapse, read our chapter on Scottsdale before 1450 and the profile of the Hohokam canal builders. This note covers the Scottsdale piece.
Turney’s map
In 1929 Omar Turney published a map of the prehistoric canals of the Salt River Valley, drawn before most of the valley was built over. The City of Scottsdale’s archaeology overview, Ancient Peoples in Scottsdale (2003), reproduces it and says what it shows here. It notes the map was made “before most of the southern part of Scottsdale was developed,” and that it “shows that the southern end of Scottsdale once contained canals that started at the Salt River to the east and extended west into Scottsdale across what is now the Salt River Pima-Maricopa Indian Community.”
The overview puts the whole Salt and Gila network at its peak around AD 1200 to 1250. Turney’s map, its caption says, shows “a maximum of 1000 miles of canals” irrigating about 100,000 acres. Main canals drew water from the river behind brush-and-rock diversions. Headgates split it into secondary canals, those split into distribution canals, and laterals carried water into the fields. The biggest canals were more than 50 feet wide and 20 feet deep, and one was measured at a fall of 1.2 to 4.8 feet per mile. That’s a gradient a modern engineer would recognize as correct.
The head of the Scottsdale Canal system
Archaeologists call the group of canals Turney drew across the south end of town the Scottsdale Canal system. The most detailed work on it appears to be a mid-1990s excavation published by Northland Research of Flagstaff. Its title is Archaeology at the Head of the Scottsdale Canal System, edited by T. K. Henderson and issued as Anthropological Papers No. 95-1. We know it from citations, not from the report itself. Its second volume, on artifacts and biological remains, includes a detailed ceramic analysis by David R. Abbott. Neither the city’s plan nor the overview we read says exactly where the dig was, and we won’t guess. “The head” of a canal system means where it left the river, which would put the work near the Salt on the Community’s side.
The pottery that ties it to the McDowells
Abbott’s ceramics connect the canal villages to the mountains. The city’s 2015 Cultural Resource Master Plan for the McDowell Sonoran Preserve says small Classic-period sites are “scattered along the southern margin of the mountains and may be seasonal occupations.” It adds: “Ceramics from the sites demonstrate a connection to sites in the Scottsdale Canal system, almost 10 miles to the south (Abbott 1995).” Then, “curiously,” those mountain-edge sites “exhibit few resources collected from the bajada.”
Abbott’s wider argument, as the plan summarizes it, is that people who shared a canal traded pottery with one another constantly. The exchange “likely cemented social relationships, fostered cooperation, and promoted a sense of shared responsibility for management of irrigation water.” If that’s right, the families camping at the foot of the McDowells in the Classic period belonged to the canal community on the river. They weren’t separate hill people. Why they went up there, and why they seem to have gathered so little once they did, is an open question.
The names on the federal map
The odd survival is in the U.S. Geological Survey’s place-name database. Its file of historical features, places that no longer exist on the ground, includes a cluster of canals entered on June 27, 1984, every one tagged “(historical).” On the Tempe quadrangle, which covers south Scottsdale and the western edge of the Community, are:
- Canal Scottsdale
- Canal Stone Hoe
- Highline Canal
- North, East and West Canal Ancho
Just east, on the Mesa quadrangle and north of the river, are Canal Ancho itself, Canal Camino (with a Lower Branch), Canal Ultimo, Canal Caliche, Canal Minor, Canal Thirteen and Canal Fourteen. Others in the same set are spread across the south side of the Mesa map and the Phoenix, Fowler and Laveen quadrangles. One on the Phoenix map is called Canal Turney.
They read like the work of someone mapping the ancient system: Spanish descriptors (ancho, wide; camino, road; último, last), numbers, and a tribute to Turney. But the gazetteer records no source and no history for any of them. That leaves real questions. Are these Turney’s own 1929 labels, or names a later archaeologist gave, perhaps in tribute to him? Are the points the gazetteer gives the canal heads, the ends, or arbitrary spots along each line? We couldn’t settle either. Turney’s original 1929 publication, Prehistoric Irrigation in Arizona, and the USGS records behind the 1984 entries would.
We’re also not reprinting the gazetteer’s coordinates. These are buried archaeological features. Most are under streets, homes and Community farmland, and the general area is all anyone needs.
What happened next
The Hohokam canals failed in the 1300s and 1400s. The city overview describes floods after about AD 1300 that wrecked headworks faster than they could be rebuilt. The people didn’t vanish. The Akimel O’odham and Piipaash who farm the Salt River today, as the Salt River Pima-Maricopa Indian Community, are their descendants. The reservation was set along Scottsdale’s eastern edge in 1879.
The next big canal here was the 1885 Arizona Canal, dug on a new, higher line. The city’s Preserve plan, citing a 2002 study, says it “altered the flow of water to the Pima irrigation system on the Salt River Reservation.” The Arizona Canal Company built an Indian Lateral in 1884 to supply the reservation, but “legal challenges by Euro-Americans ultimately reduced the level of water received on the reservation.” The Community’s water rights weren’t settled until 1988. The canal water that made Scottsdale was diverted, in part, from the people whose ancestors had first irrigated the land.
Where to see Hohokam canals
Not in south Scottsdale, as far as anyone has published. The visible remnants elsewhere are in our before-1450 chapter: a preserved channel at Mesa’s Park of the Canals, and the platform-mound village at Pueblo Grande in Phoenix, now the S’edav Va’aki Museum. For the story told by the Community itself, go to the Huhugam Ki Museum on Osborn Road, about fifteen minutes east of Old Town. It’s open weekdays only, so call first. Then ride the Arizona Canal Path west from Pima Road. The water in it comes off the river at Granite Reef Dam, upstream near the Verde confluence.
Sources: City of Scottsdale, Ancient Peoples in Scottsdale (archaeology context, March 2003) and Draft McDowell Sonoran Preserve Cultural Resource Master Plan (June 2015), including its bibliography entries for Abbott 1995 and Henderson (ed.) 1995; U.S. Geological Survey, Geographic Names Information System, Historical Features file (downloaded October 2026).