Rainbow Dam is a hydroelectric dam on the
Missouri River, high and long, located six miles northeast of
Great Falls in the
U.S. state
In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...
of
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...
.
History
The dam is named for the downstream
Rainbow Falls, a waterfall that is the third of the five
Great Falls of the Missouri. Built in 1910, the dam furnishes water to an eight-unit hydroelectric plant with a capacity of 36
megawatt
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James ...
s.
As the dam's power plant is located over a half-mile downstream, the flow of water over Rainbow Falls and downstream Crooked Falls is significantly reduced during the dry season. The water from the penstocks re-enters the river a few hundred yards east of Crooked Falls.
Montana Power Company acquired the dam when it was founded in 1912,
PPL Corporation purchased it in 1997 and sold it to
NorthWestern Corporation in 2014.
See also
*
Ryan Dam
References
External links
*
Historic American Engineering Record
Heritage Documentation Programs (HDP) is a division of the U.S. National Park Service (NPS) responsible for administering the Historic American Buildings Survey (HABS), Historic American Engineering Record (HAER), and Historic American Landscapes ...
(HAER) documentation, filed under End of Rainbow Dam Road, Great Falls, Cascade County, MT:
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Buildings and structures in Cascade County, Montana
Dams completed in 1910
Dams in Montana
Dams on the Missouri River
Gravity dams
Historic American Engineering Record in Montana
NorthWestern Corporation dams
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