Canyon Ferry Dam is a concrete gravity dam in a narrow valley of the

Missouri River The Missouri River is a river in the Central United States, Central and Mountain states, Mountain West regions of the United States. The nation's longest, it rises in the eastern Centennial Mountains of the Bitterroot Range of the Rocky Moun ...

, United States, where the Big Belt Mountains and the Spokane Hills merge, approximately downstream from the confluence of the Gallatin, Madison, and Jefferson rivers, and about east of the city of

Helena, Montana Helena (; ) is the List of capitals in the United States, capital city of the U.S. state of Montana and the county seat, seat of Lewis and Clark County, Montana, Lewis and Clark County. Helena was founded as a gold camp during the Montana gold ...

. The dam is for

flood control Flood management or flood control are methods used to reduce or prevent the detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and ru ...

, irrigation, recreation and hydroelectric power. The building of the dam created a

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

known as Canyon Ferry Lake.

Background

In 1941, the first study for the dam was carried out by the

Bureau of Reclamation The Bureau of Reclamation, formerly the United States Reclamation Service, is a List of United States federal agencies, federal agency under the U.S. Department of the Interior, which oversees water resource management, specifically as it ...

, 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 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 high and long.

Design

The dam is a tall concrete gravity type and has a length of . The crest of the dam is while the base is . The dam structure compromises a total of of concrete. The dam's

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

is located on its central portion and is controlled by four radial gates. It has a maximum discharge of . Adjacent to the spillway is the dam's power plant which contains three 16.5 MW

Francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The pro ...

generators for an installed capacity of 50 MW. Each turbine is fed with water by a diameter penstock. At a normal elevation of , the

contains of water.

References

External links

U.S. Reclamation website: Canyon Ferry Unit
{{Authority control Dams in Montana Buildings and structures in Lewis and Clark County, Montana Hydroelectric power plants in Montana Gravity dams United States Bureau of Reclamation dams Energy infrastructure completed in 1954 Dams completed in 1954 Dams on the Missouri River 1954 establishments in Montana