Origins
The Salt River Project emerged from the arid conditions of central Arizona and the ambitions of settlers who recognized that only large-scale water control could sustain permanent agriculture in the Sonoran Desert. The Salt River Valley had attracted farmers since the 1860s, who channeled water through ancient Hohokam irrigation canals abandoned centuries earlier. However, the Salt River’s extreme variability—devastating floods followed by prolonged droughts—made agriculture precarious. The flood of 1891 destroyed irrigation works throughout the valley, while droughts in the late 1890s brought farmers to the edge of ruin.
Local landowners organized the Salt River Valley Water Users’ Association in 1903, becoming the first entity to contract with the newly created U.S. Reclamation Service under the National Reclamation Act of 1902. Benjamin Fowler, a former territorial legislator, led the organizational effort, convincing thousands of landowners to pledge their properties as collateral for federal loans. This innovative structure—where water users rather than the federal government owned the irrigation works—became a model for reclamation projects nationwide. Frederick Newell, the Reclamation Service’s first director, saw the Salt River Valley as an ideal demonstration of federal irrigation’s potential.
Construction of Roosevelt Dam began in 1906 at the confluence of Tonto Creek and the Salt River, fifty miles northeast of Phoenix. The site presented formidable challenges: building materials had to be transported across roadless desert, and workers labored in extreme heat to construct what would be the world’s tallest masonry dam. President Theodore Roosevelt, the Reclamation Act’s champion, dedicated the completed dam in 1911, calling it one of the great engineering achievements of the age. The dam’s reservoir, with a capacity of 1.4 million acre-feet, could store two years’ worth of Salt River flow, transforming boom-and-bust irrigation into a reliable water supply.
Structure & Function
The Salt River Project operates as two interconnected entities: the Salt River Valley Water Users’ Association, a private corporation that manages water rights and irrigation infrastructure, and the Salt River Project Agricultural Improvement and Power District, a political subdivision of Arizona that handles electrical generation and distribution. This dual structure reflects the project’s evolution from pure irrigation to multipurpose resource management and its transition from federal reclamation to local control.
Water delivery operates through a network of 131 miles of canals and 1,300 miles of smaller laterals, serving approximately 240,000 acres across metropolitan Phoenix. Shareholders—the successors to original landowners who pledged their property in 1903—receive water based on their acreage, with assessments determined by elected representatives rather than market prices. This cooperative structure ensures that agricultural users retain access to affordable water even as urban development has transformed the valley. The project also provides municipal and industrial water to Phoenix and surrounding cities through separate agreements.
The electrical system, developed after the project repaid its federal construction loans in 1955, has grown into Arizona’s third-largest utility. Six hydroelectric dams on the Salt and Verde rivers generate renewable power, supplemented by a diverse portfolio including natural gas, coal (being phased out), nuclear (a share of Palo Verde Generating Station), and solar installations. The power district serves over one million customers across 2,900 square miles, encompassing most of metropolitan Phoenix. Unlike the water system’s shareholder governance, the power district is governed by an elected board representing all customers within its service territory.
Historical Significance
The Salt River Project demonstrated that large-scale federal investment in water infrastructure could transform arid lands into productive agricultural regions. Its success inspired expansion of the Reclamation program throughout the West, leading to construction of Hoover Dam, Grand Coulee Dam, and dozens of other projects that reshaped the American landscape. The project’s organizational model—water users forming associations to contract with the federal government—became standard practice, creating the legal and institutional framework for western water development.
The project fundamentally enabled Phoenix’s growth from a small agricultural town of 5,500 people in 1900 to America’s fifth-largest city today. Reliable water and electricity attracted industries and residents throughout the twentieth century, particularly after air conditioning became widespread. Without the Salt River Project’s infrastructure, the metropolitan area of five million people could not exist in its current form. This transformation illustrates both the possibilities and environmental consequences of large-scale water engineering.
Critics have raised concerns about the project’s environmental and social impacts. Dam construction flooded Apache sacred sites and altered the Salt River’s ecology, eliminating native fish species and riparian habitats. The heavy subsidies implicit in federal reclamation—interest-free construction loans and below-market water prices—encouraged agricultural development in regions that might otherwise remain desert. As climate change intensifies southwestern drought, questions arise about the sustainability of water systems designed during an unusually wet period in regional history. The Salt River Project continues adapting, investing in water recycling, aquifer storage, and renewable energy while navigating the tensions between agricultural heritage and urban growth.
Key Developments
- 1867: Jack Swilling organizes first modern irrigation company in Salt River Valley, using Hohokam canals
- 1891: Major flood destroys irrigation works; drought follows, demonstrating need for storage
- 1902: National Reclamation Act signed, creating U.S. Reclamation Service
- 1903: Salt River Valley Water Users’ Association formed, first federal reclamation contract signed
- 1906: Construction of Roosevelt Dam begins
- 1911: President Theodore Roosevelt dedicates completed dam; reservoir begins filling
- 1917: Mormon Flat Dam completed, second dam on Salt River
- 1925: Horse Mesa Dam completed
- 1930: Stewart Mountain Dam completed, fourth dam on Salt River system
- 1937: Bartlett Dam completed on Verde River, expanding water supply
- 1946: Horseshoe Dam completed on Verde River
- 1955: Salt River Project repays federal construction loans, becomes fully locally controlled
- 1973: Salt River Project Agricultural Improvement and Power District established
- 1986: Roosevelt Dam modification completed, increasing storage capacity
- 1996: Waddell Dam (now Lake Pleasant Dam) integrated into regional water system
- 2020: Salt River Project announces goal of 65% carbon-free electricity by 2035