Hebgen Dam is a

concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...

-core earthen

embankment dam An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface ...

in the

western Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US *Western Creek, Tasmania, a locality in Australia *Western Junction, Tasmania, a locality in Australia *Western world, countries that id ...

United States, located on the

Madison River The Madison River is a headwater tributary of the Missouri River, approximately long, in Wyoming and Montana. Its confluence with the Jefferson and Gallatin rivers near Three Forks, Montana forms the Missouri River. Course The Madison Ri ...

in southwestern

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

. The dam is tall and in length; its purpose is to store and regulate water for other downstream reservoirs and

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

power plant A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the electricity generation, generation of electric power. Power stations are generally connected to an electr ...

Montana Power Company The Montana Power Company (MPC) was an electric utility company based in Butte, Montana, which provided electricity to Montana consumers and industry from 1912 to 1997. History The Montana Power Company was founded in 1912 by John D. Ryan, the ...

originally built the dam,

PPL Corporation PPL Corporation is an energy company headquartered in Allentown, Pennsylvania in the Lehigh Valley region of eastern Pennsylvania. The company is publicly traded on the New York Stock Exchange as and is part of the S&P 500. As of 2022, the compa ...

purchased it in 1997 and sold it to

NorthWestern Corporation NorthWestern Energy Group, Inc. is a utility company that serves South Dakota, Nebraska, and Montana that is based in Sioux Falls. , the company serves approximately 718,000 customers. The company's corporate headquarters are located in Sioux Fa ...

in 2014.

History

Hebgen Dam was built across the Madison River in 1914 by Montana Power Company to create Hebgen Lake. During the 7.5 magnitude

1959 Hebgen Lake earthquake The 1959 Hebgen Lake earthquake (also known as the 1959 Yellowstone earthquake) occurred in the western United States on August 17 at 11:37 pm ( MST) in southwestern Montana. The earthquake measured 7.2 on the moment magnitude scale, caused a h ...

in mid-August, the dam was damaged, primarily due to intense ground movement that led to water surging over the dam crest four different times. It was repaired several weeks later. The epicenter of the quake was determined to be beneath the bottom of Hebgen Lake. Seismologists reported it to be the fourth largest quake recorded in the United States up to that time.Tuholske, Lily. "Yellowstone Earthquake at the Madison River." Distinctly Montana. September 9, 1998.
Accessed March 18, 2018. On August 30, 2008, two of the dam's four hydraulic gates failed, releasing per second of water into the Madison River. The normal discharge of the dam is per second and the gate failure caused a 1-foot rise in the river. On November 30, 2021, the hydraulic gates failed again causing downstream flows to rapidly drop. Nearby locals quickly organized an effort to rescue stranded fish trapped in pools in the side channels. An ongoing lawsuit against Northwestern Energy (as of 2024) claims that NWE failed in its requrirement to keep streamflows above 150 CFS.https://montanafreepress.org/2021/12/13/northwestern-energy-dam-fire-liability/

Climate

References

External links

"Yellowstone earthquake at the Madison River." Tuholske, Lily. "Yellowstone Earthquake at the Madison River." Distinctly Montana. September 9, 1998.
Accessed March 18, 2018. Dams in Montana Buildings and structures in Gallatin County, Montana Earth-filled dams NorthWestern Corporation dams Dams completed in 1914 {{US-dam-stub

History

Climate

See also

References

External links