Our new favorite winter camping spot is on the “shores” of the Gila Gravity Canal. The Parker-Gila Project was authorized in 1928 as part of the Boulder Canyon Project Act (later known as Hoover Dam); when initial surveying began in 1934, the Gila River Valley project was separated from the Colorado Indian Reservation project (Parker Dam). Project construction on the Gila Project was approved in 1937 with the potential to develop over 500,000 acres of irrigation. After World War II, the scope of the project was reduced to 40,000 acres in the Yuma Mesa Division and 75,000 acres in the Wellton-Mohawk Division.
Water for the Wellton-Mohawk (orange area below) and the Yuma Mesa (grey) Irrigation and Drainage Districts as well as for the North Gila and Yuma Irrigation Districts comes from the Gila Project.
The Gila Project diverts water from the Colorado River at Imperial Dam (the All-American Canal is also diverted from the Colorado there). Imperial Dam was preceded by the Lagunas Diversion Dam built between 1905 and 1909. It is often called the “Swastika Dam” because each masonry pier is topped with a large nine inch swastika recessed into the concrete; the Bureau of Reclaimation even used the swastika on its flag during that period. Although this may seem odd today, the swastika was used throughout the world as a positive symbol of good luck and life.
Originally used to divert water to Yuma, Sommerton, and Winterhaven Laguna Dam is 5 miles downstream of the Imperial Dam. Since diversion now happens at Imperial Dam, Laguna is used to help control the flows out of Imperial Dam.
The diverted water first passes through the Gila Desilting Basin before entering the twenty-one mile long main Gila Gravity Canal. The Canal skirts the Laguna Mountains passing through two tunnels on the northwestern side before wrapping around the southern flanks of the mountains. Tunnels 1 and 2 were completed in 1938: Tunnel 1 is 1,740 feet long and Tunnel 2 is 4,125 feet long. When the Canal reaches the Gila River, it passes below the Gila through the Gila Siphon, completed in 1939. The Fortuna Wash Siphon was completed in 1940.
Downstream of the Gila Siphon, some of the water is channeled into the Wellton-Mohawk Canal while the rest of the water flows to the eastern end of the South Gila Valley where it is lifted 52 feet by the Yuma Mesa Pumping Plant to Canals A & B that direct water around Yuma Mesa. the Wellton-Mohawk Canal water reaches its fields with the help of three pump lifts.
Construction of the main canal was hindered in the mid-1940s by labor shortages. The war effort actually encouraged the government to keep progressing on the Gila Project because irrigation was needed to control dust near the Yuma Army Air Field (now Yuma Marine Corps Air Station). A total of 8,500 acres was rushed into alfalfa production to protect airplane engines. The final phase of construction on the Gila Project distribution system was completed in 1957.
Today, the Gila Project provides irrigation water for 100,000 acres in Yuma County as well as providing domestic water for the City of Yuma. Agriculture in Yuma is a big business with an gross economic return of over $3 billion (more than 1/3 of Arizona’s total agriculture). Thanks to water from the Colorado River, Yuma is even able to call itself winter vegetable capital of the world!