Boundary — Pend Oreille, WA — Operational Power Plant
Total Capacity
1,159.7 MW
Summer: 1,144.9 MW | Winter: 1,144.9 MW
Technology
Hydro
6 generators
First Unit Online
August 1, 1967
Boundary is a hydro power plant in Pend Oreille County, WA with 6 generating units totaling 1,159.7 MW of nameplate capacity. It is operated by City of Seattle - (WA). Its first unit came online in 1967.
About this plant
Boundary Dam is a concrete arch gravity-type hydroelectric dam, finished in 1967, on the Pend Oreille River, in the U.S. state of Washington. The dam is located in the northeast corner of Washington state. It is operated by Seattle City Light and makes up a significant portion of the City of Seattle's energy portfolio. On average, it provides upwards of 46% of the power generated by Seattle City Light. Boundary Powerhouse, located adjacent to the dam, is completely built inside of the rock that makes up the left abutment of the dam itself. It has a nameplate capacity of just over 1 gigawatt of generation. The component of the hydroelectric project were listed on the National Register of Historic Places in 2018.
Source: Wikipedia
Capacity rank
- #16 in the U.S. by capacity
- #5 in WA by capacity
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Monthly generation history
Source: EIA Form 923
Generators (6)
6 generators
6 operational generators totaling 1,159.7 MW · online 1967–1986
Plant Information
| Plant ID | 6433 |
| Plant Name | Boundary |
| Operator | City of Seattle - (WA) |
| Sector | Electric Utility |
| Balancing Authority | SCL |
| Power Market | |
| County | Pend Oreille |
| State | Washington (all interconnection requests in Washington) |
| Status | Operational |
| Generation Type(s) | Hydro |
| Total Nameplate Capacity (MW) | 1159.7 |
| Total Summer Capacity (MW) | 1144.9 |
| Total Winter Capacity (MW) | 1144.9 |
| Generating Units | 6 |
| Operational Units | 6 |
| Planned Units | 0 |
U.S. county map showing Pend Oreille, WA
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