# Grand Coulee

BPA asset profile · https://askthegrid.com/assets/facilities/grand-coulee

U.S. Bureau of Reclamation - Grant County - BPAT

Grand Coulee Dam is a conventional hydroelectric and pumped-storage facility in Grant County, Washington, comprising 33 operating generating units with 6,809 MW of combined nameplate capacity. The dam and all four of its powerhouses are owned and operated by the federal U.S. Bureau of Reclamation as the centerpiece of the Columbia Basin Project. Grand Coulee is the largest hydropower generating complex in the United States, a status secured in 1980 when the last unit of the Nathaniel "Nat" Washington (Third) Power Plant came online. That Third Power Plant alone contributes 4,485 MW from six large units, roughly two-thirds of the dam's total output, while the original Left and Right Powerhouses and the John W. Keys III Pump-Generating Plant supply the rest. The complex generates an average of about 21 billion kilowatt-hours a year and, beyond power production, provides irrigation water for the Columbia Basin Project, flood control, and streamflow regulation. No whole-plant or unit retirement is scheduled; the dam continues to operate under Reclamation, with its Third Power Plant currently undergoing a multi-year rehabilitation of all six units.

## Metrics

- **Nameplate capacity:** 6809 MW — Canonical EIA plant baseline.
- **Registry anchor:** Plant 6163 — plant-6163

## Facts

- **Technology:** Hydroelectric Pumped Storage, Conventional Hydroelectric
- **Operator:** U.S. Bureau of Reclamation

## Related parties

- **Equipment supplier:** Willamette Iron and Steel Company — Manufacturer of G19–G21 Francis turbines
- **Equipment supplier:** Allis-Chalmers — Designer and manufacturer of G22–G24 Francis turbines

## Sources

- [apps.ecology.wa.gov](https://apps.ecology.wa.gov/publications/documents/2414020.pdf) — apps.ecology.wa.gov · authoritative — Source retained for exact-record publication review.
- [bpa.gov](https://www.bpa.gov/about/newsroom/news-articles/2022/20220302-generators-like-new-again-at-nations-largest-hydroelectric-producer) — bpa.gov · authoritative — Source retained for exact-record publication review.

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Canonical page: https://askthegrid.com/assets/facilities/grand-coulee
Website: [U.S. Bureau of Reclamation](https://www.usbr.gov/pn/grandcoulee/)

Source: Ask the Grid — https://askthegrid.com/