6th largest plant in Washington · 268th nationally
Boundary is a hydroelectric power plant in Washington with a nameplate capacity of 1,119 MW. It generates roughly 2.8M MWh per year — enough to power about 271,036 average U.S. homes.
Its capacity factor of 29% reflects intermittent or peaking operation.
| Plant Name | Boundary |
|---|---|
| Operator | City Of Seattle - (Wa) |
| City | Metaline |
| County | Pend Oreille County |
| State | Washington |
| ZIP | 99152 |
| Coordinates | 48.98711, -117.34785 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| 55 | Conventional Hydroelectric | Water | 239 MW | Operating | 1985 |
| 56 | Conventional Hydroelectric | Water | 239 MW | Operating | 1986 |
| 51 | Conventional Hydroelectric | Water | 181 MW | Operating | 1967 |
| 54 | Conventional Hydroelectric | Water | 181 MW | Operating | 1967 |
| 52 | Conventional Hydroelectric | Water | 162 MW | Operating | 1967 |
| 53 | Conventional Hydroelectric | Water | 158 MW | Operating | 1967 |
| NERC Region | WECC |
|---|---|
| Balancing Authority | Seattle City Light |
Hydroelectric plants spin turbines using falling or flowing water — typically from a dam-impounded reservoir. They are dispatchable, long-lived, and emission-free at the point of generation, though large reservoirs can disrupt rivers and ecosystems and methane can be released from flooded vegetation.