In Lincoln County, Washington (WA). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.

How big is Long Lake?

70 MW of nameplate capacity across 4 units, as of the EIA-860M release for 2026-07.

EIA-860M names Avista Corp as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.

Is this the same as Long Lake LLC?

Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Avista Corp here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Long Lake LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.

Is Long Lake still running?

EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.

Long Lake

Long Lake is a 70 MW hydroelectric power plant in Lincoln County, Washington, operated by Avista Corp. EIA-860M lists 4 generating units here. Its units entered service between 1915 and 1924.

As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m

Nameplate capacity: 70 MW; 89.5 MW net summer
Generating units: 4
In service: 1915–1924
EIA plant ID: 3867

Where it is

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County: Lincoln County, Washington
Coordinates: 47.8344, -117.8361
Balancing authority: AVA
Sector: Electric Utility

Units, technology and status

Operator of record: Avista Corp
Primary energy source: Hydro
Technologies: Conventional Hydroelectric
Status: Operating

Every plant Avista Corp reports to EIA →

Long Lake: FAQ

Where is Long Lake?: In Lincoln County, Washington (WA). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
How big is Long Lake?: 70 MW of nameplate capacity across 4 units, as of the EIA-860M release for 2026-07.
Who owns Long Lake?: EIA-860M names Avista Corp as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
Is this the same as Long Lake LLC?: Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Avista Corp here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Long Lake LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
Is Long Lake still running?: EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.