Boundary
Hydro power plant in Pend Oreille County, Washington. 1,159.7 MW of nameplate capacity across 6 generators, operated by City of Seattle - (WA).
Also known as Boundary Dam Powerhouse · EIA plant 6433
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 1,159.7 MWNameplate
- Generators
- 6 operatingEIA-860M, August 2026
- Operating since
- August 1967First generator online
- Operator
- City of Seattle - (WA)EIA operator ID 16868
- Grid
- SCLBalancing authority SCL
- Price nodes
- 6 CAISO nodesResource nodes with prices
- Location
- Pend Oreille County, WA48.9871, −117.3478
- EIA plant ID
- 6433EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power Boundary produces
Free · EIA-923Net generation, 2025
3.10 TWh
3,099,497 MWh, final
Capacity factor, 2025
30.5%
2024: Not reported
January to July 2026
2.95 TWh
Provisional
Range, 2015 to 2025
2.8–4.0
TWh a year. Low 2023, high 2018
| Year | Net generation, MWh | Capacity factor | Months reported |
|---|---|---|---|
| 2000 | 3,786,081 | Not reported | 12 of 12 |
| 2001 | 2,334,054 | Not reported | 12 of 12 |
| 2002 | 3,955,178 | Not reported | 12 of 12 |
| 2003 | 3,570,090 | Not reported | 12 of 12 |
| 2004 | 3,496,940 | Not reported | 12 of 12 |
| 2005 | 3,454,063 | Not reported | 12 of 12 |
| 2006 | 4,312,432 | Not reported | 12 of 12 |
| 2007 | 3,624,709 | Not reported | 12 of 12 |
| 2008 | 3,812,524 | Not reported | 12 of 12 |
| 2009 | 3,587,038 | Not reported | 12 of 12 |
| 2010 | 3,138,414 | 34.5% | 12 of 12 |
| 2011 | 4,491,278 | 49.3% | 12 of 12 |
| 2012 | 3,795,417 | 41.6% | 12 of 12 |
| 2013 | 3,459,270 | 38.0% | 12 of 12 |
| 2014 | 4,243,407 | 46.6% | 12 of 12 |
| 2015 | 3,465,956 | Not reported | 12 of 12 |
| 2016 | 3,884,516 | 39.5% | 12 of 12 |
| 2017 | 3,821,117 | 39.0% | 12 of 12 |
| 2018 | 4,003,841 | 40.9% | 12 of 12 |
| 2019 | 3,300,777 | 33.7% | 12 of 12 |
| 2020 | 3,570,026 | 36.3% | 12 of 12 |
| 2021 | 3,204,939 | 32.7% | 12 of 12 |
| 2022 | 3,706,219 | 37.8% | 12 of 12 |
| 2023 | 2,845,880 | Not reported | 12 of 12 |
| 2024 | 3,020,283 | Not reported | 12 of 12 |
| 2025 | 3,099,497 | 30.5% | 12 of 12 |
| 2026 (provisional, partial year) | 2,947,292 | 49.9% | 7 of 7 |
* 2026 covers January to July and is provisional. Capacity factor is net generation divided by nameplate capacity times the hours of each reported month.
Power prices and basis
Free account · CAISOEmissions
Free · EPA CAMPDNo EPA emissions units are linked to this plant.
Water use
Free · EIA-923 cooling, USGSNo EIA cooling-water record for this plant in 2024. Plants without steam cooling, such as wind, solar and batteries, do not report cooling water.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| 51 | Conventional Hydroelectric | 180.5 | October 1967 |
| 52 | Conventional Hydroelectric | 161.5 | August 1967 |
| 53 | Conventional Hydroelectric | 158.4 | September 1967 |
| 54 | Conventional Hydroelectric | 180.5 | August 1967 |
| 55 | Conventional Hydroelectric | 239.4 | November 1985 |
| 56 | Conventional Hydroelectric | 239.4 | May 1986 |
Ownership and offtake
ProOwnership and offtake are part of Pro
Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists City of Seattle - (WA) as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
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Power plants near Boundary
More plants operated by City of Seattle - (WA)
Questions about Boundary
How much power does Boundary produce?
Boundary reported 3,099,497 MWh (3.10 TWh) of net generation in 2025, a 30.5% capacity factor on 1,159.7 MW of nameplate capacity. From January to July 2026 it reported 2.95 TWh, which is provisional.
Where is Boundary?
Boundary is in Pend Oreille County, Washington, at 48.9871, −117.3478. It is in the Seattle City Light balancing area (SCL).
Who operates Boundary?
EIA-860M for August 2026 lists City of Seattle - (WA) as the operator (EIA operator ID 16868). The operator is not always the owner.
When did Boundary start operating?
Its first generator began operating in August 1967, according to EIA-860M.
Does InfraMap have power prices for Boundary?
Yes. InfraMap has CAISO day-ahead and real-time prices at 6 price nodes linked to Boundary, with the hub price and node-to-hub basis. Prices are free with an InfraMap account; pricing node names are part of InfraMap Pro.
Sources
- EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
- EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
- CAISO day-ahead and real-time prices; node and hub assignments as of 2026-10-05
- Plant names from OpenStreetMap, © OpenStreetMap contributors (ODbL)
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page