Salt River

Salt River

The river that made Phoenix: Hohokam canals, one of the first big dams of the Reclamation era, and floods that took out the Valley's bridges.

Map of the Salt RiverWhite MountainsMogollon RimSierra AnchaMazatzal MountainsSuperstition MountainsSalt RiverGlobeVerde RiverBlack RiverCarrizo CreekPinal CreekWhite River25 miles
Salt River. River lines from the USGS National Hydrography Dataset.

People and the river

Saguaros on the Salt River desert before irrigation.
Saguaros on the Salt River desert before irrigation.Library of Congress, public domain · source
A buggy fording the Salt at Tempe, 1870s–1880s.
A buggy fording the Salt at Tempe, 1870s–1880s.Tempe Historical Museum, via the Historic American Engineering Record, Library of Congress, public domain · source
  1. About A.D. 450–1450The Hohokam built a network of canals and laterals from the Salt across the valley, then left it around 1400–1450.1,2
  2. 1867–68Jack Swilling's company dug out the old Hohokam canals and irrigated again; Phoenix grew beside them.1
  3. 1903Valley landowners formed the Salt River Valley Water Users' Association in February, pledging their land against federal reclamation loans; the Salt River Project was authorized on March 14.3,1
  4. 1911President Theodore Roosevelt dedicated Roosevelt Dam on March 18. At 280 feet it was the tallest masonry dam in the world; its supplies came up a 60-mile road built from the railhead at Mesa.4,5,1
  5. 1925–1930The water users built three more dams downstream with their own money: Mormon Flat (Canyon Lake, 1925), Horse Mesa (Apache Lake, 1927) and Stewart Mountain (Saguaro Lake, 1930).6,7,8
  6. 1996Roosevelt Dam was resurfaced in concrete and raised 77 feet, adding flood-control space.5

Biggest flows

A dragline at work in the Salt River at Mormon Flat in 1923, as the dam that made Canyon Lake was built.
A dragline at work in the Salt River at Mormon Flat in 1923, as the dam that made Canyon Lake was built.Salt River Project, via the Historic American Engineering Record, Library of Congress, public domain · source
~300,000cfs
Salt River at Phoenix, February 1891, the largest flood recorded on the Salt.9
estimated
~155,000cfs
Inflow to Roosevelt Lake, March 1978, the largest known from 1890 to 1978.10
estimated

Measured: a USGS gauge reading. Estimated: reconstructed after the fact from high-water marks or flood deposits. Provisional: USGS readings not yet reviewed.

Floods that mattered

February 1891

The flood left Phoenix without a rail connection for three months.9

March 1978

The highest flow on the Salt through Phoenix since 1920.10

1980

Floods destroyed or damaged 11 of the 13 bridges across the Salt in the Valley.11

The Salt River and its Tributaries

Map of the Salt River and its tributaries in central and east-central Arizona, with White Mountains, Mogollon Rim, Sierra Ancha: rivers, side canyons, contour lines and summit elevations, in a classic survey style.
A classic map of the river and the mountains around it. Full size · Vector (SVG) · © 2026 Southwest River Watch
Sources
  1. Water History: The First Five, a brief history of the Salt River Project
  2. SAH Archipedia: The Salt River and Canals
  3. Bureau of Reclamation: Salt River Project
  4. Bureau of Reclamation: Theodore Roosevelt Dam
  5. Wikipedia: Theodore Roosevelt Dam
  6. SRP: Mormon Flat Dam and Canyon Lake
  7. SRP: Horse Mesa Dam and Apache Lake
  8. Historic American Engineering Record: Stewart Mountain Dam
  9. Wikipedia: Phoenix flood of 1891
  10. USGS: Floods of October 1977 in southern Arizona and March 1978 in central Arizona (WSP 2223)
  11. 12 News: the 1980 Phoenix floods

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