Lower Granite Lock and Dam is a concrete gravity

run-of-the-river Run-of-river hydroelectricity (ROR) or run-of-the-river hydroelectricity is a type of hydroelectric generation plant whereby little or no water storage is provided. Run-of-the-river power plants may have no water storage at all or a limited amou ...

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

in the

northwest United States The Northwestern United States, also known as the American Northwest or simply the Northwest, is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, Idaho, Montana and Wyoming. ...

. On the lower

Snake River The Snake River is a major river of the greater Pacific Northwest region in the United States. At long, it is the largest tributary of the Columbia River, in turn, the largest North American river that empties into the Pacific Ocean. The Snake ...

in southeastern

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

, it bridges Whitman and

Garfield ''Garfield'' is an American comic strip created by Jim Davis. Originally published locally as ''Jon'' in 1976, then in nationwide syndication from 1978 as ''Garfield'', it chronicles the life of the title character Garfield the cat, his human ...

counties. Opened in 1975, the dam is located south of Colfax and north of Pomeroy. Lower Granite Dam is part of the

Columbia River Basin The Columbia River drainage basin is the drainage basin of the Columbia River in the Pacific Northwest region of North America. It covers . In common usage, the term often refers to a smaller area, generally the portion of the drainage basin th ...

system of dams, built and operated by the

U.S. Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cl ...

Corps of Engineers; power generated is distributed by the

Bonneville Power Administration The Bonneville Power Administration (BPA) is an American federal agency operating in the Pacific Northwest. BPA was created by an act of Congress in 1937 to market electric power from the Bonneville Dam located on the Columbia River and to constr ...

(BPA). Behind the dam, Lower Granite Lake extends east to the confluence with the Clearwater River at

Lewiston, Idaho Lewiston is a city and the county seat of Nez Perce County, Idaho, United States, in the state's north central region. It is the second-largest city in the northern Idaho region, behind Coeur d'Alene, and ninth-largest in the state. Lewiston is ...

, and allowed the city to become a port. The first barge to

Portland Portland most commonly refers to: * Portland, Oregon, the largest city in the state of Oregon, in the Pacific Northwest region of the United States * Portland, Maine, the largest city in the state of Maine, in the New England region of the northeas ...

on the navigation route was loaded with wheat and departed Lewiston on August 9, 1975. Lake Bryan, formed from

Little Goose Dam Little Goose Lock and Dam is a hydroelectric, concrete, run-of-the-river dam in the northwest United States, on the lower Snake River in southeast Washington. At the dam, the river is the border between Columbia and Whitman counties; it is ...

, runs downstream from the base of the dam.

Construction

Construction began in July 1965, but was halted less than two years later due to lack of funding. Work restarted in 1970, concrete was first poured in 1971, and the main structure and three generators were completed in 1975, with dedication ceremonies on June 19. An additional three generators were finished in May bringing the generating capacity to 810 megawatts, with an overload capacity of 932 MW. The spillway has eight gates and is in length. An navigation lock was also included in construction. Just downstream (northwest) of the dam on the east bank, Boyer Park was constructed by the Corps of Engineers and opened in April 1973.

Fishery

Lower Granite Dam is the most upstream dam in the Snake River system that has a

fish ladder A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon is a structure on or around artificial and natural barriers (such as dams, locks and waterfalls) to facilitate diadromous fishes' natural migration as well as movemen ...

to allow adult

salmon Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...

and

steelhead Steelhead, or occasionally steelhead trout, is the common name of the anadromous form of the coastal rainbow trout or redband trout (O. m. gairdneri). Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and N ...

to migrate upstream. The Columbia River treaty tribes, along with some environmental groups, have recommended that this dam along with the other three lower Snake River dams be decommissioned and/or removed because of their impact on threatened and endangered chinook (threatened) and

sockeye The sockeye salmon (''Oncorhynchus nerka''), also called red salmon, kokanee salmon, blueback salmon, or simply sockeye, is an anadromous species of salmon found in the Northern Pacific Ocean and rivers discharging into it. This species is a P ...

salmon (endangered) and steelhead (threatened) populations., The Corps of Engineers recognized in 1971 that the dam would have a detrimental impact on wildlife. A significant increase in the sockeye salmon return to the Columbia River in 2008 proved a pleasant surprise and raised hopes for increased salmon runs across the Lower Granite. Wildlife officials were not certain of the reason for the increased salmon return (''Idaho Statesman,'' June 28, 2008). The Corps of Engineers has installed new devices, such as removable spillway

weir A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...

s, in an attempt to make the dam less harmful to juvenile salmon. There is also a juvenile bypass/collection facility that collects juvenile migrating salmon and steelhead so they can be transported downstream by barge.

Navigation lock

* Single-lift * Width: * Length: LwrGrDam2

Asotin Dam

Authorized by

Congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of a ...

in 1962, a fifth dam on the lower Snake River was proposed several miles upstream (south) of Lewiston. Concerns over its environmental and recreational impact stalled the Asotin Dam project, and it was ultimately canceled in 1980. The

Asotin County Asotin County () is a county in the U.S. state of Washington. As of the 2020 census, the population was 22,285. The county seat is at Asotin, and its largest city is Clarkston. The county was created out of Garfield County in 1883 and derive ...

public utilities district attempted to revive the project in 1988, but it was quickly blocked by Congress, and a law banning future dams was signed into law by

President President most commonly refers to: *President (corporate title) *President (education), a leader of a college or university *President (government title) President may also refer to: Automobiles * Nissan President, a 1966–2010 Japanese ful ...

Reagan Ronald Wilson Reagan ( ; February 6, 1911June 5, 2004) was an American politician, actor, and union leader who served as the 40th president of the United States from 1981 to 1989. He also served as the 33rd governor of California from 1967 ...

on November 17. Other proposed dams further upstream were not built either: the High Mountain Sheep Dam above the confluence with the Salmon River, and the Nez Perce Dam, just below it.

Road closed

Following the

September 11 attacks The September 11 attacks, commonly known as 9/11, were four coordinated suicide terrorist attacks carried out by al-Qaeda against the United States on Tuesday, September 11, 2001. That morning, nineteen terrorists hijacked four commercia ...

in 2001, the road across the Lower Granite Dam was closed for over six years; it reopened for weekend traffic in May 2008. The sand dune area downstream on the south shore (), accessed over the dam, was popular with local college students from

Washington State University Washington State University (Washington State, WSU, or informally Wazzu) is a public land-grant research university with its flagship, and oldest, campus in Pullman, Washington. Founded in 1890, WSU is also one of the oldest land-grant unive ...

and the

University of Idaho The University of Idaho (U of I, or UIdaho) is a public land-grant research university in Moscow, Idaho. It is the state's land-grant and primary research university,, and the lead university in the Idaho Space Grant Consortium. The University ...

References

External links

U.S. Army Corps Engineers: Lower Granite Dam
*
Lower Granite Recreation

Columbia River Inter-Tribal Fish Commission

Fish Passage Center Dam Counts

History Link: Lower Granite Dam

Boyer Park and Marina
{{Authority control Dams in Washington (state) Buildings and structures in Garfield County, Washington Hydroelectric power plants in Washington (state) Buildings and structures in Whitman County, Washington Run-of-the-river power stations United States Army Corps of Engineers dams Dams completed in 1984 Energy infrastructure completed in 1972 Energy infrastructure completed in 1979 Dams on the Snake River Gravity dams 1975 establishments in Washington (state) Dams with fish ladders