Canyon Ferry Dam
Background
In 1941, the first study for the dam was carried out by the Bureau of Reclamation, the Montana Water Board and Montana Power Company. The dam and power plant were part of the Pick-Sloan Plan and approved by the Flood Control Act of 1944 which was signed on December 22. Known as the Canyon Ferry Unit, construction began on May 24, 1949, and was completed on June 23, 1954. On December 18, 1953, the power plant's first generator became operational and the other two went online in 1954.
The 1949 structure replaced the original Canyon Ferry Dam 1.5 mi (2 km) upstream. The original dam was constructed between 1896 and 1898 by the Helena Water and Electric Power Company. It was a timber crib dam with rock-fill and was 29 ft (9 m) high and 485 ft (148 m) long.
Design
The dam is a 225 ft (69 m) tall concrete gravity type and has a length of 1,000 ft (305 m). The crest of the dam is 20 ft (6 m) while the base is 173 ft (53 m). The dam structure compromises a total of 414,400 cu yd (316,832 m) of concrete. The dam's spillway is located on its central portion and is controlled by four radial gates. It has a maximum discharge of 150,000 cu ft/s (4,248 m/s). Adjacent to the spillway is the dam's power plant which contains three 16.5 MW Francis turbine generators for an installed capacity of 50 MW. Each turbine is fed with water by a 13.5 ft (4 m) diameter penstock. At a normal elevation of 3,797 ft (1,157 m), the reservoir contains 1,891,000 acre⋅ft (2.332514155×10 m) of water.
References
- ^ "Canyon Ferry Dam". U.S. Bureau of Reclamation. Retrieved 2018-04-26.
- ^ "Canyon Ferry Unit". U.S. Bureau of Reclamation. Retrieved 25 March 2017.
- ^ Wegmann, Edward (1918). The design and construction of dams (6 ed.). University of Michigan: John Wiley & Sons, inc. pp. 293.
Canyon Ferry Dam.