Alder — Plant Summary
- EIA Plant ID
- 3913
- Capacity
- 50 MW
- Primary Fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Status
- Operating
- Location
- Pierce, WA
- Operating Since
- 1945
- Generators
- 2
- Operator
- City of Tacoma - (WA)
- Parent Company
- —
- Annual Generation
- 182,852 MWh
- Capacity Factor
- 41.6%
- Balancing Authority
- City of Tacoma, Department of Public Utilities, Light Division
- ISO/RTO
- —
- NERC Region
- WECC
Alder
OperatingHydro
Ranked #32 of 75 Hydro plants in WA#299 of 1454 nationally
50 MW Hydro operating in Pierce, WA — City of Tacoma, Department of Public Utilities, Light Division
EIAGEMWD
50 MW
Nameplate Capacity
2
Generators
units
Conventional Hydroelectric
Technology
1945
Operating Since
Location
Coordinates
46.8016, -122.3102
County
Pierce, WA
Nearby Plants
- LaGrandeHydro64 MW · 3.5 km
- LRI LFGTE FacilityLandfill Gas4.5 MW · 19.4 km
- Skookumchuck Wind FacilityWind136 MW · 22.9 km
Ownership & Operator
Owner data does not fully agree across sources.
EIA typically reports the operating utility, while GEM resolves to the financial owner or parent corporation. Both can be correct.
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | City of Tacoma - (WA) | City of Tacoma (WA) | — |
| Owner(s) | City of Tacoma - (WA) | City of Tacoma (WA) | — |
| Status | Operating | operating | — |
Ownership Chain
GEM identifies the owner as City of Tacoma (WA)
This entity is not yet in the GEM ownership database — chain unavailable.
About
Alder Dam is a concrete thick arch dam on the Nisqually River in the U.S. state of Washington. 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, stretching about 7 miles (11 km) upstream with a capacity of 241,950 acre-feet (0.29844 km3). With 28 miles (45 km) of shoreline, the lake is a popular recreation spot close to Mount Rainier National Park.
Read more on WikipediaThe Alder hydroelectric plant, located in Pierce County, Washington, has a total capacity of 50 MW. The plant began operating in 1945 and utilizes conventional hydroelectric technology. It is owned and operated by the City of Tacoma, Washington. Alder is ranked as the 32nd largest power plant in Washington out of 75, and 302nd nationally out of 1464 plants.
The plant consists of two generators and uses water as its primary fuel source. In the most recent year with available data, Alder generated 182,852 MWh of electricity, achieving a capacity factor of 41.6%. The balancing authority for the plant is the City of Tacoma, Department of Public Utilities, Light Division, and it operates within the Western Electricity Coordinating Council (WECC) NERC region.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
City of Tacoma, Department of Public Utilities, Light Division
Grid Voltage
110 kV
Regulatory Status
RE
Entity Type
Municipal
Sector
Electric Utility
Generation
24.2K MWh
Latest Month
182.9K MWh
Annual Generation
41.6%
Capacity Factor
Jan 2022 – Dec 2024
Financial Data
No financial data available for this plant.
Pricing & Market Data
This plant is outside organized wholesale electricity markets (ISOs/RTOs). Nodal pricing data is not available.
News & Articles (10)Beta
Last updated 2026-03-26
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