Hohokam Canals
The Hohokan people dug a sophisticated network of canals in the Salt River Valley as a foundation for a flourishing civilization. With a population estimated to be as many as 80,000 individuals at its height, the culture flourished for more than 1000 years in the unforgiving Sonoran desert before disappearing in about 1450 CE.
The Hohokam people lived in the Mesa area for nearly 1,500 years. Hohokam, (a Pima Indian word meaning ‘‘those who have disappeared’’), first appeared around 1 CE initially growing beans, squash, corn and cotton serving a very small population of less than one thousand. Around 600 CE, the Hohokam population grew too large for sustainable living. As the population grew further from the river, the Hohokam began to construct canals for irrigation. Using digging sticks, the Native Americans excavated 12-feet deep canals, fanning into a larger network of smaller canals.
Because of their extensive excavation abilities, the Hohokam were considered to be engineering geniuses. Their ability to push water effectively for several 100 miles over a flat desert landscape, while evading hills and valleys complimented their legacy. Creating a stabilized canal system they transported water through minimal changes in elevation and overcame natural ebbs and flows that rivers create. In areas of excessive water(flow), the Hohokam would widen the channel. In areas of inadequate water(ebb); the channel would be narrowed, increasing velocity of water. This increase in velocity, decreased sediment buildup, discharge into fields and evaporation. If they allowed the water to stagnate, those three elements occur.
To maximize potential of water to exit river into canals, the Hohokam developed several techniques. A weir, or partial dam, forced water into the head gate of the canal, creating maximum force, and more efficiently carrying water to the local farms. The headgates were made out of wood and giant rocks, withstanding the rivers immense strength. The Hohokam canal stretched nearly 500 miles and would serve up to 50,000 natives at any given time. There is no universally accepted evidence on why they disappeared, only speculation. The most viable reason was outgrowing their capacity to sustain life in the desert. Especially during periods of environmental stress, all but vanished by 1450.
The Hohokam effort to build irrigation canals became the foundation of economic and urban development of Arizona. Jack Swilling, a Mexican War and Confederate States Army Veteran, headed west in the late 1850’s to work as an ox-train teamster. Ten years later, a central Arizona gold rush brought many miners near the Salt river. Needing a constant supply of water, the miners and soldiers observed the landscape. Upon discovering the Hohokam canals, Swilling analyzed their potential and restored them as a viable water delivery source. With sixteen other miners, he received a loan to create ditches, minimizing watershed, to successfully raise wheat, barley and corn. He redirected the delivery of water from the Salt River via the canals and ditches (modern day 32nd St. and Van Buren), to sell to miners in Wickenburg and infantry stationed at Ft. McDowell. The Swilling Irrigating Canal Company, as his company came to be called, revitalized the irrigation system and enticed more people to settle in the area. Englishman ‘‘Lord’’ Darrell Duppa”, recognized the symbolism of a new agricultural civilization rising from old Hohokam canals. He said: ‘‘A city will rise phoenix-like, new and beautiful, from these ashes of the past,’’ and renamed the new community Phoenix.”
Around the 1880, Charles T. Hayden, father of Carl; was an early Arizona settler who observed the many farmlands the canals serviced and was also compelled by the success of Swilling Irrigation and Canal Co. On a business venture, Charles was on a freighting trip to Wickenburg when a severe storm and flooding of the Salt River forced him to wait several days. The delay gave opportunity to examine the surrounding land, where he envisioned a thriving agricultural community. As the foundation for the farming was laid out, Charles observed corn and vegetables successfully growing by the Swilling ditch, an increase in settlers and with an entrepreneurial mind. He began to entertain the idea of a gristmill.
Nearing the end of the nineteenth century, local promoters recognized that a more stable water supply was needed to continue population and economic growth. With high variable flows, the Salt River; and many rivers alike, were subject to very low flows followed by substantially large floods. There was also a substantial amount of water loss that was a pressing issue. In 1891, flood waters raged through the heart of the agricultural valley, destroying irrigation headgates and canals. One local resident commented: ‘‘Chocolate in color, hideous in its roaring fury, the torrent spared nothing in its path.’’ The floods were followed by a severe drought between 1898 and 1904, resulting in the loss of thousands of crop acres. Men would patrol the river with rifle in hand, ensuring locals were not taking more than their fair share. But from this environmental near-disaster came a successful regional movement to build an upstream dam to retain, stabilize and protect the area from flooding.
Carl Hayden was directly affected by this flooding and witnessed his father's business take a substantial loss. Fighting for his father's vision, he travelled to Washington to lobby for the Salt River Project as Congress debated the Federal Reclamation Act in 1902. He was Arizona's primary influence on federal policy making in natural resource development, water reclamation, and land-use management. Due to his vision and effort, Carl is considered Arizona's most important individual to reshaping from pioneered settled to a modern urban state.
Tonto Basin became the ideal location for a dam, but securing the finances to build it would prove difficult. Local ranchers and farmers created the Salt River Water Users Association (SRWUA). They pledged their lands as collateral to obtain a loan large enough to allow the building of the Tonto Basin and Roosevelt Dam. In 1902 a National Reclamation Act was passed into law allowing government loans to reclaim the West with irrigation projects. Creation of the Theodore Roosevelt Dam and improving existing Hohokam canals, the government sought to improve water retention and delivery velocity of water by modernizing the canals. They did this by laying cement and replacing the head gates with a more reinforced cement delivery.
SRWUA would restore Canals and built dams by the use of hydroelectric generators. The generators allowed the government to slowly pay the local farmers for their investment. In 1917 the operation of the canal system was turned over to the Salt River Water Users Association, later developed into Salt River Project (SRP). The SRP succeeded in supporting a growing population. Receiving government loans, during the next 30 years, SRP would erect the following dams and canals respectively; Mormon Flat Dam in 1925, Mesa Dam in 1927, Stewart Mountain Dam in 1930, Bartlett Dam in 1939, Horseshoe Dam and Sixth Storage Dam, 1946. These dams allowed for maximum water retention and manageable delivery. The canals that SRP created are, The Grand Canal: 22.43 miles, Consolidated Canal: 18.95 miles, Eastern Canal: 14.73 miles, Western Canal: 13.61 miles South Canal: 9.91 miles, Tempe Canal: 9.76 miles, and New Crosscut Canal: 3.4 miles, serving more than six million today.
While the canals were technically created to deliver water to a desert metropolis, they have historically been associated with recreation as well. Being considered a part of Arizona’s social fabric, the canals were popular places for walking, running, biking and horseback riding. Reducing the need for heavy equipment, SRP released white amurs, a kind of Asian carp. This cleaned up the moss and weeds that were associated with dirtying the water with algae. The Arizona Canal, near Scottsdale, displays art, holds special events, contains pedestrian bridges, landscaped walkways and easy access to canalside shops and restaurants.
Images
