Flood irrigation turns a barren landscape green
Without irrigation, the dry plains of northwest Wyoming and southern Montana would be barren—brown, desolate and covered in wind-blown sage. But a series of flood irrigation projects that deliver mountain water to the plains below has transformed the Bighorn Basin into a rich agricultural area, while providing wetlands for recreation and wildlife.
The Shoshone Project in the Cody area is the largest project, supplemented by smaller projects throughout the mountain ranges surrounding the Basin.
The Shoshone Project
Operated by the Bureau of Reclamation, the Shoshone Project includes two major features in the Absaroka Range—the Buffalo Bill Dam and Buffalo Bill Reservoir. The massive concrete 350-foot, arch-gravity Buffalo Bill Dam on the Shoshone River was the vision of “Buffalo Bill” Cody, who founded the nearby town of Cody and owned much of the land now covered by the Buffalo Bill Reservoir. It was built in the early 1900s, and opened in 1910 as the world’s largest dam. The Buffalo Bill Reservoir is one of the largest in Wyoming, containing a 100-year-supply of irrigation water for the region.
Other features of the Shoshone Project include the Shoshone and Heart Mountain power plants and associated transmission facilities, and a network of tunnels, smaller dams and reservoirs, canals and laterals to deliver water to the project lands. Water from the Shoshone River is diverted into four irrigation divisions in the Cody and Powell areas:
Corrugation, flood irrigation
At the farm, growers use corrugation irrigation to flood irrigate fields. Corrugating irrigation uses small furrows, called corrugations, to guide water across a field. The corrugations are added after the barley has been planted. When the barley needs watering, the grower contacts the irrigation district. Water is then delivered to canals running along the fields, and the grower diverts the water using siphons or lock and gate pipes. In northwest Wyoming, where rainfall can be as little as 4-5 inches a year, growers typically irrigate 4-5 times each growing season. In southern Montana, growers with access to flood irrigation typically irrigate 2-3 times a year, as rainfall averages are higher there.
Producing barley and electricity
In addition to providing water for agriculture, the Shoshone Irrigation Project is a major supplier of electricity to the Basin. Its power plants generate over 91 million kilowatt hours of electricity each year. In perspective, in 2015 the average home in the U.S. consumed 10,812 kilowatt hours of electricity.