Lower Granite — Plant Summary
- EIA Plant ID
- 6175
- Capacity
- 810 MW
- Primary Fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Status
- Operating
- Location
- Whitman, WA
- Operating Since
- 1975
- Generators
- 6
- Operator
- USACE Northwestern Division
- Parent Company
- —
- Annual Generation
- 1,461,002 MWh
- Capacity Factor
- 20.6%
- Balancing Authority
- Bonneville Power Administration
- ISO/RTO
- —
- NERC Region
- WECC
Lower Granite
OperatingHydro
Ranked #10 of 75 Hydro plants in WA#31 of 1454 nationally
810 MW Hydro operating in Whitman, WA — Bonneville Power Administration
EIAGEMWD
810 MW
Nameplate Capacity
6
Generators
units
Conventional Hydroelectric
Technology
1975
Operating Since
Location
Coordinates
46.6595, -117.4294
County
Whitman, WA
Nearby Plants
- Biotech LS 0836Distillate Oil1 MW · 22.2 km
- Grimes WayNatural Gas4 MW · 22.6 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 | USACE Northwestern Division | US Army Corps of Engineers - Walla Walla District | United States Army Corps of Engineers |
| Owner(s) | USACE Northwestern Division | US Army Corps of Engineers - Walla Walla District [100%] | — |
| Status | Operating | operating | — |
Ownership Chain
GEM identifies the owner as US Army Corps of Engineers - Walla Walla District [100%]
This entity is not yet in the GEM ownership database — chain unavailable.
About
Lower Granite Lock and Dam is a concrete gravity run-of-the-river dam in southeastern Washington in the United States. On the lower Snake River, it bridges Whitman and Garfield counties. Opened 51 years ago in 1975, the dam is located 22 miles (35 km) south of Colfax and 35 miles (56 km) north of Pomeroy.
Read more on WikipediaLower Granite is a hydroelectric power plant located in Whitman County, Washington. The plant, which began operating in 1975, has a total capacity of 810 MW distributed across 6 generators. It is owned and operated by the USACE Northwestern Division. The plant utilizes conventional hydroelectric technology with water (WAT) as its primary fuel source.
In the most recent year with available data, Lower Granite generated 1,461,002 MWh of electricity, achieving a capacity factor of 20.6%. The plant operates within the Bonneville Power Administration balancing authority and the Western Electricity Coordinating Council (WECC) NERC region. Lower Granite is ranked as the 8th largest power plant out of 23 in Washington state, and 29th out of 194 hydroelectric plants nationally.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
Bonneville Power Administration
Grid Voltage
500 kV
Regulatory Status
RE
Entity Type
Federal
Sector
Electric Utility
Generation
191.4K MWh
Latest Month
1.5M MWh
Annual Generation
20.6%
Capacity Factor
Jan 2023 – Dec 2025
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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