This is a list of dams and reservoirs in the U.S. state of Washington, and pertinent data. According to the Washington State Department of Ecology, as of 2020 there were 1226 dams in the state. Of 39 counties, King County had the most dams, 125. [1]
The largest dam in Washington, in terms of structural volume, reservoir capacity and electricity production, is the Grand Coulee Dam on the Columbia River. The tallest dam is Mossyrock Dam on the Cowlitz River, at 606 feet (185 m). The longest dam is O'Sullivan Dam on Crab Creek, at 19,000 feet (5,800 m).
Key | ||||
---|---|---|---|---|
† Located on state border with Oregon |
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, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions.
The Cowlitz River is a river in the state of Washington in the United States, a tributary of the Columbia River. Its tributaries drain a large region including the slopes of Mount Rainier, Mount Adams, and Mount St. Helens.
The Cedar River is a river in the U.S. state of Washington. About 45 miles (72 km) long, it originates in the Cascade Range and flows generally west and northwest, emptying into the southern end of Lake Washington. Its upper watershed is a protected area called the Cedar River Watershed, which provides drinking water for the greater Seattle area.
The Elwha River is a 45-mile (72 km) river on the Olympic Peninsula in the U.S. state of Washington. From its source at Elwha snowfinger in the Olympic Mountains, it flows generally north to the Strait of Juan de Fuca. Most of the river's course is within the Olympic National Park.
Lake Chelan Dam officially known as the Lake Chelan Hydroelectric Project is located approximately 32 miles (51 km) north of the city of Wenatchee in Chelan County. The dam is located at the lower or southeasterly end of 50.4 miles long Lake Chelan, and is within the limits of the city of Chelan. The powerhouse is located near the community of Chelan Falls. The reservoir has 677,400 acre-feet (835,600,000 m3) of usable water storage. The 10-year average generation for the Project is 365,000 megawatt hours.
Condit Hydroelectric Project was a development on the White Salmon River in the U.S. state of Washington. It was completed in 1913 to provide electrical power for local industry, and is listed in the National Register of Historic Places as an engineering and architecture landmark.
The Kensico Reservoir is a reservoir spanning the towns of Armonk and Valhalla, New York, located 3 miles (5 km) north of White Plains. It was formed by the original earth and gravel Kensico Dam constructed in 1885, which impounded waters from the Bronx and Byram rivers. In 1917, a new masonry dam was completed, replacing the old dam and expanding the water supply by bringing water from the Catskill Mountains over a distance of more than 100 miles.
The Elwha Dam was a 108-ft high dam located in the United States, in the state of Washington, on the Elwha River approximately 4.9 miles (7.9 km) upstream from the mouth of the river on the Strait of Juan de Fuca.
Chester Morse Lake is a lake in the upper region of the Cedar River watershed in the U.S. state of Washington. The original lake surface was 1,530 feet above sea level, but when the river was dammed in 1900, the elevation was raised to 1,560 feet. Chester Morse Lake is more than four miles (6 km) long, and is primarily fed from the east by the north and south forks of the Cedar River, and from the south by the Rex River. The lake is part of the Seattle area water supply.
Jackson Lake Dam is a concrete and earth-fill dam in the western United States, at the outlet of Jackson Lake in northwestern Wyoming. The lake and dam are situated within Grand Teton National Park in Teton County. The Snake River emerges from the dam and flows about eight hundred miles (1,300 km) through Wyoming, Idaho, Oregon, and Washington to its mouth on the Columbia River in eastern Washington.
Kachess Lake is a lake and reservoir along the course of the Kachess River in Washington state, US. The upper part of the lake, north of a narrows, is called Little Kachess Lake. The Kachess River flows into the lake from the north, and out from the south. Kachess Lake is the middle of the three large lakes which straddle Interstate 90 north of the Yakima River in the Cascade Range. The other two are Cle Elum Lake, the easternmost which is also north of I-90 and Keechelus Lake, the westernmost, which is south of I-90.
Dam removal is the process of demolishing a dam, returning water flow to the river. Arguments for dam removal consider whether their negative effects outweigh their benefits. The benefits of dams include hydropower production, flood control, irrigation, and navigation. Negative effects of dams include environmental degradation, such as reduced primary productivity, loss of biodiversity, and declines in native species; some negative effects worsen as dams age, like structural weakness, reduced safety, sediment accumulation, and high maintenance expense. The rate of dam removals in the United States has increased over time, in part driven by dam age. As of 1996, 5,000 large dams around the world were more than 50 years old. In 2020, 85% percent of dams in the United States are more than 50 years old. In the United States roughly 900 dams were removed between 1990 and 2015, and by 2015, the rate was 50 to 60 per year. France and Canada have also completed significant removal projects. Japan's first removal, of the Arase Dam on the Kuma River, began in 2012 and was completed in 2017. A number of major dam removal projects have been motivated by environmental goals, particularly restoration of river habitat, native fish, and unique geomorphological features. For example, fish restoration motivated the Elwha Ecosystem Restoration and the dam removal on the river Allier, while recovery of both native fish and of travertine deposition motivated the restoration of Fossil Creek.
The Elwha Ecosystem Restoration Project is a 21st-century project of the U.S. National Park Service to remove two dams on the Elwha River on the Olympic Peninsula in Washington state, and restore the river to a natural state. It is the largest dam removal project in history and the second largest ecosystem restoration project in the history of the National Park Service, after the Restoration of the Everglades. The controversial project, costing about $351.4 million, has been contested and periodically blocked for decades. It has been supported by a major collaboration among the Lower Elwha Klallam Tribe, and federal and state agencies.
Gibraltar Dam is located on the Santa Ynez River, in southeastern Santa Barbara County, California, in the United States. Forming Gibraltar Reservoir, the dam is owned by the city of Santa Barbara. Originally constructed in 1920 and expanded in 1948, the dam and reservoir are located in a remote part of the Los Padres National Forest.
The following outline is provided as an overview of and topical guide to infrastructure of the U.S. state of Washington.
Seattle Municipal Light and Power Plant, also known as Cedar Falls Historic District, is a public hydroelectric plant near North Bend, Washington operated by Seattle City Light. The plant was the first publicly-owned electrical generating plant for Seattle and one of the earliest in the country for a municipality of its size. It was listed on the National Register of Historic Places in 1997.
Eightmile Lake is a reservoir lake located on the eastern slope of Eightmile Mountain, in Chelan County in Washington. It is a reservoir lake formed along the beginning route of Eightmile Creek as it exits Jack Ridge.
Colchuck Lake is a freshwater reservoir lake located on the western slope of The Enchantments, in Chelan County, Washington. The lake is located approximately 15 miles from the city of Leavenworth, Washington and sits on the southeast corner of the Icicle Creek subbasin. It is accessed by a 4-mile trail that starts at USFS Road 7601 as it crosses over Eightmile Creek and makes a turn towards the Stuart and Culchuck Lake Trailhead where the road ends. The origin of the word comes from Chinook Jargon kol + cak to mean cold waters.
Snow Lakes are a system of freshwater reservoir lakes made by Upper Snow Lake and Lower Snow Lake, approximately a mile long. They are located on the eastern slope of The Enchantments, in Chelan County, Washington. The Snow Lakes are one of the most heavily used destination in the Forest Service wildernesses in Oregon and Washington. Self-issued Alpine Lakes Wilderness permits are required for transit within the Snow Lakes area.