Hydroelectric Plants

Idaho Power owns and operates 17 hydroelectric plants on the Snake River and its tributaries. They make up our largest source of electrical generation.

The original American Falls Power Plant was built in 1902, acquired by Idaho Power in 1916 and rebuilt by the U.S. Bureau of Reclamation in 1927.

Idaho Power added a power plant in 1976 when the Bureau again rebuilt the dam. It has three generators with a total nameplate generating capacity of 92,340 kilowatts. The dam is used primarily for irrigation and secondarily for power production and recreation opportunities. It’s located at river mile 714.7.

Idaho Power owns and operates Trenner Park on the south end of the reservoir.

Bliss Power Plant was completed in 1950 and includes a powerhouse and three generators with a total nameplate generating capacity of 75,000 kilowatts. It’s located at river mile 560.3.

The Hagerman Valley section of our Parks and Campgrounds page describes the many Idaho Power recreational facilities in the area.

Our largest project with five generators rated at 585,400 kilowatts, Brownlee was completed in 1959 and is the most upstream of the three dams in the Hells Canyon Complex. It is located at river mile 285.0. Today the three-dam complex provides power, flood control and recreation opportunities to the region. Brownlee Dam and Reservoir’s name is derived from nearby Brownlee Creek, most likely named after the Brownlee family who settled the area in 1862 and operated a ferry across the Snake during the late 1800s.

Visit the Woodhead Park section for information about our facilities in this area.

The Baker County Hewitt/Holcomb Parks web page has more information about this area.

Named after former Idaho Power President C.J. Strike, the plant was completed in 1952. Located on the Snake River southwest of Mountain Home, Idaho, at river mile 494.0, the plant’s three generators have a total nameplate generating capacity of 82,800 kilowatts.

Visit the C. J. Strike Parks section of our Parks and Campgrounds page for information about our facilities in this area.

Originally built in 1926 on a Payette River diversion by the U.S. Bureau of Reclamation, a new plant was completed in 1984 that uses the dam’s full power production potential. The plant has two generators with a total nameplate generating capacity of 12,420 kilowatts. Generation is tied to seasonal reservoir releases for irrigation controlled by the Bureau of Reclamation.

The Idaho Department of Parks and Recreation operates the recreational facilities at Cascade reservoir.

This is Idaho Power’s smallest power generator, with a nameplate generating capacity of 2,500 kilowatts. We built the plant in 1937 as part of a development phase during the Great Depression. It is located on the Snake River near Buhl, Idaho, at river mile 593.0. Underground springs supply the water used to generate power.

Visit the Hagerman Valley section of our Parks and Campgrounds page for information about Idaho Power recreational facilities in the area.

Located 21 miles downstream of Oxbow Dam, Hells Canyon Dam is the third and last project in the Hells Canyon Project. It began generating electricity in 1967 and has a nameplate generating capacity of 391,500 kilowatts.

See the Hells Canyon section of our Parks and Campgrounds page for descriptions of Idaho Power recreational facilities in the area.

The Beaver River Power Company built the original Lower Malad Power Plant in 1911 on the Malad River. Idaho Power acquired the plant in 1916. Today the Lower Malad Power Plant is located on the Snake River at river mile 571.2. It diverts water from the Malad River to a powerhouse equipped with one generator rated at 13,500 kilowatts.

The Upper Malad and Lower Malad Power Plants were redeveloped after World War II. Located near Hagerman, Idaho, the Upper Malad Power Plant has a nameplate generating capacity of 8,270 kilowatts. It includes a diversion dam at river mile 2.1 on the Malad River, a concrete gravity structure, and a powerhouse with one generator.

Visit the Hagerman Valley section of our Parks and Campgrounds page for information about Idaho Power recreational facilities in the area.

Milner Dam was built in the early 1900s for irrigation. Idaho Power and Milner Dam, Inc. improved the dam and added a hydroelectric power plant in 1992. The nameplate capacity for this plant is 59,448 kilowatts.

Oxbow takes its name from a three-mile bend in the Snake River. Early settlers said this part of the river resembled the U-shaped collar around an ox’s neck. Located 13 miles downstream of Brownlee Dam, Oxbow is one of the world’s most unusual dam sites.

Completed in 1961, it was the second dam of the Hells Canyon Project and is rated at 190,000 kilowatts.

Visit the McCormick Park section for information about our facilities in this area.

The Lower Salmon Falls Power Plant was built in 1910 by the Greater Shoshone and Twin Falls Water Power Company. Idaho Power acquired the plant in 1916 and rebuilt it in 1949. The plant has a total nameplate generating capacity of 60,000 kilowatts and includes a dam and powerhouse with four generators. It’s located at river mile 573.0.

Upper Salmon Falls is one project with two power plants: Upper Salmon A and B. Idaho Power built Upper Salmon A in 1937. The plant includes a diversion structure and two generators with a total nameplate generating capacity of 18,000 kilowatts. It’s located at river mile 579.6.

Upper Salmon B Power Plant is located upstream from Upper Salmon A Power Plant at river mile 580.8. Built in 1947, Upper Salmon B comprises a diversion structure and two generators with a total nameplate generating capacity of 16,500 kilowatts.

Visit the Hagerman Valley section of our Parks and Campgrounds page for information about Idaho Power recreational facilities in the area.

Built in 1907, Shoshone Falls was the first power plant in Idaho’s Magic Valley. It was acquired by Idaho Power in 1916 and rebuilt in 1921. Shoshone Falls Power Plant is located on the Snake River near Twin Falls, Idaho, at river mile 614.7. The plant has a nameplate generating capacity of 11,500 kilowatts. It includes a diversion dam and a powerhouse with three generators.

Visit the Shoshone and Twin Falls Parks page for information about our facilities in this area.

This was the first power plant built on the Snake River. Located near Kuna, Idaho, at river mile 457.7, the original plant was built in 1901 to supply electricity to nearby mines. Idaho Power acquired the plant in 1916.

Originally there were 10 generators rated at 10,400 kilowatts which were decommissioned in 1994 along with the old powerhouse. That powerhouse is now a historic display. A new powerhouse with two generating units called “pit turbines,” was completed in 1994 which increased the project’s nameplate generating capacity to 27,170 kilowatts.

Visit the Swan Falls page for information about camping, boat ramps a day-use park and other facilities in this area.

The Thousand Springs site had many developers and owners but it wasn’t until 1912 that power was first generated at the site by the Thousand Springs Power Company. It’s located at river mile 584.7. Idaho Power acquired the site in 1916 and updated the plant in 1921. The current plant includes diversion structures and a powerhouse with three generators with a total nameplate generating capacity of 6,800 kilowatts.

Visit the Hagerman Valley section of our Parks and Campgrounds page for information about Idaho Power recreational facilities in the area.

Idaho Power built the original plant in 1935 and updated it in 1995 with a diversion structure and two powerhouses with a total nameplate generating capacity of 52,897 kilowatts. It’s located at river mile 617.

Visit the Shoshone and Twin Falls Parks page for information about our facilities in this area.