Alder Dam is a concrete thick arch

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 ...

on the

Nisqually River The Nisqually River is a river in west central Washington in the United States, approximately long. It drains part of the Cascade Range southeast of Tacoma, including the southern slope of Mount Rainier, and empties into the southern end of Pu ...

in the

U.S. The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

state of

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 ...

. The construction began in 1942 and was completed in 1945. At this time Alder Dam was among the tallest dams in the United States, although this title has since been surpassed. The impounded water behind the dam forms

Alder Lake Alder Lake is Intel's codename for the 12th generation of Intel Core processors based on a hybrid architecture utilizing Golden Cove performance cores and Gracemont efficient cores. It is fabricated using Intel's Intel 7 process, previousl ...

, stretching about upstream with a capacity of . With of shoreline, the lake is a popular recreation spot close to

Mount Rainier National Park Mount Rainier National Park is an American national park located in southeast Pierce County and northeast Lewis County in Washington state. The park was established on March 2, 1899, as the fourth national park in the United States, preservi ...

Water from Alder Lake is sent into two generators at the base of the dam, each of which produces 25 Megawatts for a total nameplate capacity of 50 Megawatts. Two miles downstream is

LaGrande Dam LaGrande Dam (or La Grande Dam) is a hydroelectric dam on the Nisqually River, on the border of Pierce County and Thurston County, Washington. LaGrande is the lesser of two coordinated dams on the Nisqually, situated two miles north (downstream) ...

, site of the first dam in the area, dating from 1912, and rebuilt in 1945 along with Alder's construction. Most of the energy produced at the dam is sent to the city of Tacoma, about north. Both Alder and LaGrande dams are owned and operated by

Tacoma Power Tacoma Power is a public utility providing electrical power to Tacoma, Washington and the surrounding areas. Tacoma Power serves the cities of Tacoma, University Place, Fircrest, and Fife, and also provides service to parts of Steilacoom, L ...

. The name of the lake and the dam recalls the former small town of Alder, which was flooded in 1945 by the impounded water of the lake and disappeared. The current community of

Alder Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...

is located north of the reservoir.

References

{{stack, {{Portal, United States, Water, Renewable energy Dams in Washington (state) United States power company dams Hydroelectric power plants in Washington (state) Buildings and structures in Pierce County, Washington Buildings and structures in Thurston County, Washington Dams completed in 1945 Energy infrastructure completed in 1945 Tacoma Public Utilities