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

72 MW of nameplate capacity across 1 unit, as of the EIA-860M release for 2026-07.

EIA-860M names Oakdale&South San Joaquin Irrigation D. 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 Donnells LLC?

Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Oakdale&South San Joaquin Irrigation D. 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 "Donnells LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.

Is Donnells still running?

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

Donnells

Donnells is a 72 MW hydroelectric power plant in Tuolumne County, California, operated by Oakdale&South San Joaquin Irrigation D.. EIA-860M lists 1 generating unit here, inside CAISO. Its unit entered service in 1957.

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: 72 MW; 72 MW net summer
Generating units: 1
In service: 1957
EIA plant ID: 415

Where it is

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County: Tuolumne County, California
Coordinates: 38.2467, -120.0341
Balancing authority: CISO
Sector: IPP Non-CHP

Units, technology and status

Operator of record: Oakdale&South San Joaquin Irrigation D.
Primary energy source: Hydro
Technologies: Conventional Hydroelectric
Status: Operating

Every plant Oakdale&South San Joaquin Irrigation D. reports to EIA →

Donnells: FAQ

Where is Donnells?: In Tuolumne County, California (CA). 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 Donnells?: 72 MW of nameplate capacity across 1 unit, as of the EIA-860M release for 2026-07.
Who owns Donnells?: EIA-860M names Oakdale&South San Joaquin Irrigation D. 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 Donnells LLC?: Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Oakdale&South San Joaquin Irrigation D. 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 "Donnells LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
Is Donnells still running?: EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.