Hydroelectric Plants in Washington
Bonneville-1
Location: WA
Operator: U.S. Army Corps of Engineers
Configuration: 10 X 53 MW Kaplan
Operation: 1938-1982
T/G supplier: SMS, GE
Quick facts: Bonneville Lock & Dam is on the lower Columbia River in the Columbia Gorge National Scenic Area. There are two powerhouses -- one started operation in 1938 and the second in 1982. On 20 Jul 2010, the plant was rededicated after a 17yr, $140mn retrofitting effort. USACE replaced 21 transformers, rewound all 10 generators, replaced all 10 turbine runners with fish-friendly models, rebuilt the switchyard, repaired wicket gates, bridge cranes and rails, and replaced all 10 electrical governors.

Photograph courtesy of USACE
Posted 15 Jan 2001

Boundary Dam
Location: WA
Operator: Seattle City Light
Configuration: 4 X 138 MW, 2 X 200 MW Francis
Operation: 1967-1986
T/G supplier: Nohab, GE, Toshiba
Quick facts: Boundary Dam on the Pend d'Oreille River is a 340ft high, 740ft long thin-arch dam. The dam is 32ft thick at its base and 8ft thick at the crest.

Photograph courtesy of Seattle City Light
Posted 1 Aug 2001

Diablo Dam
Location: WA
Operator: Seattle City Light
Configuration: 2 X 75 MW Francis
Operation: 1936-1937
T/G supplier: SMS, WH
Quick facts: When it was dedicated in 1930, Diablo Dam was the world's highest at 389ft.

Photograph courtesy of Seattle City Light
Posted 28 Feb 2001

Electron
Location: WA
Operator: Electron Hydro LLC
Configuration: 3 X 6 MW, 1 X 7.5 MW impulse
Operation: 1904-1929
T/G supplier: Pelton Water Wheel, GE
EPC: Stone & Webster, Bihler and Rydstrom, Porter Bros
Quick facts: Thhis HPP began generatinon on 12 Apr 1904 aftr 2yrs of construction by a workforce of 1,500 to 2,000 men and 600 teams of horses. The plant was heavily damaged by a landslide in 1936, but it was fully restoired. The flume was rebulit in 1985. In Nov 2014, the plant was sold by Puget Sound Energy to the current ownership team.

Photograph courtesy of Electron Hydro LLC
Posted 20 Feb 2016

Elwha Dam
Location: WA
Operator: U.S. Bureau of Reclamation
Configuration: 2 X 3 MW, 2 X 3.3 MW Francis
Operation: 1914-1922 (ret)
T/G supplier: WSM, WH
EPC: L L Summers and Co
Quick facts: The Elwha River flows northward from the Olympic Mountains to the Straight of Juan de Fuca near Port Angeles. The upper watershed of the Elwha River is located within Olympic National Park and within a Wilderness Area. The Elwha River is the fourth largest river on the Olympic Peninsula. The mean annual runoff is 76 inches. Private companies constructed two large dams on the Elwha River during the early 1900s, Elwha Dam and Glines Canyon Dam. Elwha Dam, constructed from 1910-13, is a 105ft high concrete gravity dam that forms Lake Aldwell 8mi upstream from the river's mouth. When the dams were first built, they were significant producers of electricity on the Olympic Peninsula. Today, the dams generate about 40% of the electricity needs for the Diashowa America paper mill in Port Angeles, Washington. The two dams have no facilities for the upstream passage of anadromous fish and in 1994 their removal was agreed to improve the regional fishery. In 2000, the U.S. Department of the Interior purchased Elwha and Glines Canyon Dams in preparation for their removal. The power stations were closed on 1 Jun 2011.

Photograph by C Harmon (Panoramio)
Posted 1 Jun 2011

Enloe Dam
Location: WA
Operator: Okanogan Public Utility District
Configuration: 2 X 1.6 MW Pelton
Operation: 1920 (ret 1958)
T/G supplier: ??
EPC: C F Uhden
Quick facts: The Enloe Dam hydro project is on the Similkameen River nortwest of Oroville. It was built by Okanogan Valley Power Co and named after the company's president Eugene Enloe. The powerhouse is 850ft downstream from the dam. The project was sold to WashingtonWater Power Co in 1923 and then sold to Okanogan Public Utility District in 1942. Power operations stopped in 1958. A 4.1-MW project rebuild was proposed by OPUD and provisionally licensed by FERC in 1983 and 1996, and then resubmitted in 2008. Photo is from Jul 1990.

Photograph courtesy of Library of Congress
Posted 5 Aug 2012

Glines Canyon Dam
Location: WA
Operator: U.S. Bureau of Reclamation
Configuration: 1 X 16 MW Francis
Operation: 1927
T/G supplier: WSM, GE
EPC: L L Summers and Co
Quick facts: In 1925, Northwestern Power and Light Co began construction on the 210ft, single-arch Glines Canyon Dam 14mi upstream from the Elwha River mouth. It was completed in 1927, forming the 415ac Lake Mills reservoir. Demolition of the Glines Canyon and Elwha Dams is scheduled for 2014.

Photograph courtesy of U.S. National Park Service
Posted 1 Jun 2011

Grand Coulee
Location: WA
Operator: U.S. Bureau of Reclamation
Configuration: 18 X 125 MW, 3 X 600 MW, 3 X 805 MW Francis
Operation: 1941-1974
T/G supplier: Newport News, Williamette Iron & Steel, WH, CGE
EPC: USBR, MWAK Co, Consolidated Builders -- 3rd phase, Vinnell, Dravo, Lockhead, Mannix
Quick facts: This is the largest power plant in the USA and its 550ft high, 5,223ft long gravity dam is one of the largest concrete structures in the world containing just under 12mn yd³ of concrete. Development started in the 1920s and the design evolved from a low-head dam to a high-head structure by the time final authorization and funding was received in 1935. Construction started on 16 Jul 1933 and completed in Jul 1942. The first phase, 150,000hp turbines were shipped 5,000mi by sea from Newport News Shipbuilding and Drydock Co as they would not clear rail tunnels on a direct route. They were the largest hydro turbines in the world at the time, records eclipsed by the third-phase turbines in the 1970s. The T/G sets have been modified and upgraded over the years. Grand Coulee was the subject for the first comercial Power Plant Trading Card published in Dec 2000.

Photograph courtesy of USBR
Re-posted 17 Nov 2013

Ice Harbor
Location: WA
Operator: U.S. Army Corps of Engineers
Configuration: 3 X 90 MW, 3 X 111 MW Kaplan
Operation: 1961-1976
T/G supplier: AC, GE
Quick facts: Construction on the Ice Harbor Project began in December 1955.

Photograph courtesy of USACE
Posted 18 May 2002

Koma
Location: WA
Operator: Covanta Energy
Configuration: 1 X 14 MW Pelton
Operation: 1990
T/G supplier: Sulzer Escher Wyss, GE
EPC: ESS Consulting, Ebasco
Quick facts: Koma Kulshan is a run-of-the-river hydroelectric generation facility located on the slopes of Mt Baker, north of Seattle. It started commercial operation in Oct 1990 and is owned by Koma Kulshan Associates, in turn indirectly owned by Covanta Energy (50%), Atlantic Holdings (49.75%) and Mt Baker Corp (0.25%). The project has a 50yr hydro license from FERC and sells its electrical output to Puget Sound Energy under a long-term PPA expiring in 2037.

Photograph courtesy of Covanta
Posted 8 Mar 2008

Lake Chelan
Location: WA
Operator: Chelan County PUD No 1
Configuration: 2 X 24 MW Francis
Operation: 1927
T/G supplier: SMS, GE
EPC: Stone & Webster
Quick facts: The first dam built to raise the level of Lake Chelan was completed in 1892, but washed out and was replaced the following year by another structure built by the newly formed Chelan Water Power Co in 1893. The company was taken over in 1899 by Chelan Electric Co in 1906, which in turn was purchased by Washington Water Power Co in 1925. A year later, Washington Water Power received a 50yr license to construct the existing dam and powerhouse. The first generating unit was placed in commercial operation in Sep 1927, followed by the second unit 11mos later. The steel-reinforced concrete gravity dam is approximately 40ft high and 490ft long. Water is sent to the powerhouse by a 2.2mi underground penstock. The powerhouse is 140ft long and 124ft. The original turbines were replaced in 1985 and 1986.

Photograph courtesy of Chelan County PUD No 1
Posted 5 Oct 2008

Little Falls
Location: WA
Operator: Avista Corp
Configuration: 4 X 8 MW Francis
Operation: 1910-1911
T/G supplier: I P Morris, GE
EPC: Washington Water Power Co
Quick facts: Little Falls is 30mi upstream of the Spokane River's confluence with the Columbia River. The project was directly authorized by an act of the U.S. Congress in 1905 and when completed, it represented a 50% increase in the generating capacity of Washington Water Power Co. The plant's four, 750-ton, 9,000hp turbines were the largest in the world at completion. The powerhouse has ornate brass fixtures and marble control panels and is on the National Register of Historic Places. The project cost less than $1.6mn to build.

Photograph courtesy of Avista Corp
Posted 13 Oct 2007

Little Goose
Location: WA
Operator: U.S. Army Corps of Engineers
Configuration: 6 X 135 MW
Operation: 1970-1978
T/G supplier: Baldwin Locomotive Works, AC, GE
Quick facts:Little Goose Dam is a concrete-gravity type, with an earthfill right abutment embankment and measures 2,655ft long with an effective height of about 100 feet. It is located at the head of Lake West, the reservoir formed by Lower Monumental Dam. The project has a navigation lock and an eight-bay spillway. Electricity output is about 2 TWh/yr.

Photograph courtesy of USACE
Posted 14 Oct 2007

Long Lake
Location: WA
Operator: Avista Corp
Configuration: 2 X 18.2-MW, 2 X 22.6-MW Francis
Operation: 1915-1924
T/G supplier: I P Morris, GE
EPC: Washington Water Power Co
Quick facts: When it was completed in 1915, Long Lake's 213ft dam was the world's highest spillway dam and its turbines were also the largest (both in size and capacity) of any in existence at the time. The construction camp built for workers at the site had a general store, post office, cement laboratory, office building, steam laundry, hotel, barber, cookhouse, a 250-person-capacity dining room, and a clubhouse featuring movies and vaudeville acts. The plant’s 24mi reservoir, commonly called Long Lake or Lake Spokane, has many recreational sites and part of the lake is adjacent to Riverside State Park, which includes more than 500ac of land donated by Avista.

Photograph courtesy of Avista Corp
Posted 13 Oct 2007

Lower Baker
Location: WA
Operator: Puget Sound Energy
Configuration: 1 X 79 MW, 1 X 30 MW Francis
Operation: 1960-2013
T/G supplier: SMS, GE, Litostroj, Koncar
Quick facts: The Baker River Hydroelectric Project in the north Cascade Mountains is the largest of PSE's hydro complexes. Lower Baker Dam is a 285ft high, 550ft long concrete gravity-arch structure. It was completed in 1925 by a construction crew of 1,300, The dam’s downstream powerhouse, which initially housed three turbines, was destroyed in 1965 by a major earthslide. PSE rebuilt the powerhouse and brought it back into service in 1968 with a single turbine. A second T/G set was added and this commissioned in June 2013.

Photograph by NateMartin (Panoramio)
Posted 18 Jan 2014

Lower Granite
Location: WA
Operator: U.S. Army Corps of Engineers
Configuration: 6 X 135 MW Kaplan
Operation: 1975-1978
T/G supplier: BLD, WH, AC, GE
Quick facts: Lower Granite Dam is 3,200ft long with an effective height of 100ft.

Photograph by Doug Thiele and courtesy of USACE
Posted 18 Aug 2001

Lower Monumental
Location: WA
Operator: U.S. Army Corps of Engineers
Configuration: 6 X 135 MW Kaplan
Operation: 1969-1981
T/G supplier: BLH, AC, GE
Quick facts: Construction on Lower Monumental started in Jun 1961.

Photograph courtesy of USACE
Posted 18 May 2002

Mayfield
Location: WA
Operator: Tacoma Power
Configuration: 4 X 40 MW propeller
Operation: 1963
T/G supplier: AC, Voest, Siemens Allis
EPC: Harza Engineering Co, Tacoma Power, Arundel Dixon Corp
Quick facts: Development of the Cowlitz River for hydroelectric power production dates to 1923 when the City of Chehalis obtained rights from the state. In 1926, the city sold its rights to a private investor, who in 1933 obtained a permit to build a dam at the Mayfield site. This project did not advance and in 1946, Tacoma Power acquired the the development rights and applied for a permit from the Federal Power Commission. In Nov 1951, the FPC granted a 50yr license to build and operate Mayfield and Mossyrock dams and construction at Mayfield got underway in Jul 1955. The Mayfield Dam was completed in 1962 and formed the 2,250ac Mayfield Lake, now a year-round recreation destination. The dam is 850ft long and 185ft high. An 860ft tunnel connects the reservoir to the powerhouse. Total cost of the dam was $44.5mn.

Photograph courtesy of Tacoma Power
Posted 14 Jun 2006

Mossyrock
Location: WA
Operator: Tacoma Power
Configuration: 2 X 150 MW propeller
Operation: 1968
T/G supplier: Newport News, ASEA
EPC: Harza Engineering Co, Dravo Corp, Al Johnson Construction Co
Quick facts: Mossyrock Dam is the tallest in Washington state at 606ft. In Jun 2006, GE Energy was selected to upgrade the two units. Two new turbines will be fabricated and installed by 2009. GE will also replace the wicket gate seals, exciters, and generator stator, refurbish the rotors, and modernize the governor with a new digital control system. The Mossyrock reservoir is known as Riffe Lake and is 23mi long.

Photograph courtesy of Tacoma Power
Posted 14 Jun 2006

Priest Rapids
Location: WA
Operator: Grant County PUD
Configuration: 10 X 95 MW Kaplan
Operation: 1959-1961
T/G supplier: EE
EPC: Harza, Merritt-Chapman & Scott
Quick facts: Priest Rapids is a concrete and earthfill dam 10,103ft long. Dam and power plant construction cost $166mn and started in July 1956.

Photograph courtesy of Grant County PUD
Posted 29 Dec 2004

Rock Island
Location: WA
Operator: Chelan County PUD
Configuration: 1 X 15 MW, 3 X 20.7 MW, 6 X 22.5 MW Kaplan, 8 X 51.3 MW bulb
Operation: 1931-1978
T/G supplier: AC, GE, Neyrpic, Alsthom
EPC: Stone & Webster
Quick facts: Rock Island was the first dam to span the Columbia River and is near the geographical center of Washington State. In Dec 1928, an application was filed with the FPC  for site investigation and a license application was submitted in Jun 1929 by Washington Electric Co, a subsidiary construction corporation of Puget Sound Power & Light, then an affiliate of Stone & Webster Corp. The license was authorized in Oct 1929 and construction started in Jan 1930. The dam, powerhouse and first four operating units were turned over on 1 Feb 1933. Installation of six additional units began in Jul 1951 and was completed in Apr 1953. Construction of a second powerhouse to supply Alco started in Aug 1974 and finished in Aug 1979. At completion, its bulb turbines were the largest in the world. The scheme includes a 590ft gravity dam section is in front of the left bank fishway and connects to a 870ft headwork incorporating the first powerhouse. The spillway is divided by the center fishway and has a total length of 1,424ft and connects to the 470ft second powerhouse structure.

Photograph courtesy of U.S. Environmental Protection Agency
Posted 7 Oct 2007

Rocky Reach
Location: WA
Operator: Chelan County PUD
Configuration: 7 X 111.2, 4 X 125.4 MW Kaplan
Operation: 1961-1973
T/G supplier: AC, WH, Dominion Bridge
EPC: Stone & Webster
Quick facts: Chelan County PUD received a preliminary FPC permit for the Rocky Reach project in Aug 1954 and a construction license was issued in Jul 1956. The first seven units were placed in operation on 1 Nov 1961, six months ahead of schedule. The original project cost $273.1mn. In May 1968, the FPC authorized the installation of four more units. These were planned after ratification of the Columbia River Treaty and make use of water released from Canadian reservoirs and the Libby Dam reservoir in Montana. Construction of the second phase began in Apr 1969, completing 1 Dec 1971. All 11 units at Rocky Reach are equipped with adjustable blade turbines.

Photograph by Garrett Fitzgerald (Wikipedia)
Posted 7 Oct 2007

Ross Dam
Location: WA
Operator: Seattle City Light
Configuration: 4 X 90 MW
Operation: 1952-1954
T/G supplier: Neport News, Baldwin Southworks, WH
EPC: Columbia Construction Co (Kaiser), General Construction Co
Quick facts: Ross Dam, originally Ruby Dam, is a 540ft high, 1,300ft long arch dam on the Skagit River. It forms a lake 24mi long, which can store 11.5mn acre-ft of water.

Photograph courtesy of Seattle City Light
Posted 18 Jul 2001

Roza
Location: WA
Operator: U.S. Bureau of Reclamation
Configuration: 1 X 12.9 MW Francis
Operation: 1958
T/G supplier: PWW, AC
Quick facts: The Roza Division is a 72,500ac tract north of the Yakima River supplied with irrigation water by the Roza Canal. The Roza power plant is adjacent to the Roza Canal.

Photograph courtesy of USBR
Posted 10 Mar 2005

 
Wanapum
Location: WA
Operator: Grant County PUD
Configuration: 10 X 104 MW Kaplan
Operation: 1959-1961
T/G supplier: Dominion Engineering, GE
EPC: Harza, Grant County Constructors (Morrison-Knudsen)
Quick facts: Wanapum is a concrete and earthfill dam 8,637ft long. Power plant construction cost $195mn and started in Jul 1959. A new-design, six-blade turbine from Voith has been installed as part of the U.S. Dept of Energy's Advanced Hydroturbine Program. All 10 T/G sets are to be changed out at a cost of about $150mn.

Photograph courtesy of Grant County PUD
Posted 29 Dec 2004

Wells
Location: WA
Operator: Douglas County PUD No 1
Configuration: 10 X 77.4 MW Kaplan
Operation: 1967-1969
T/G supplier: AC
Quick facts: PUD No 1 of Douglas County was organized in 1936 and began operations in 1945. The design of the Wells project is unusual in that the generating units, spillways, switchyard and fish passage facilities are combined into a single 1,130ft long structure. The project includes the Wells Hatchery just west of the dam and two 41mi, 230kV single-circuit transmission lines to Douglas Switchyard near Rocky Reach Dam. The Wells Reservoir is 29.5mi long.

Photograph courtesy of Douglas County PUD No 1
Posted 13 Oct 2007

Abbreviations

Data: industcards, Platts UDI World Electric Power Plants Data Base

Updated 20-Feb-2016

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