Twin Reservoirs
581 Mill Creek Road, Walla Walla, WA 99362Plant Summary Information
Twin Reservoirs is ranked #63 out of 70 hydroelectric power plants in Washington in terms of total annual net electricity generation.
Twin Reservoirs is comprised of 1 generator and generated 1.2 GWh during the 3-month period between September 2025 to December 2025.
| Plant Name | Twin Reservoirs |
|---|---|
| Utility Name | City of Walla Walla - (WA) |
| Location | Walla Walla County, WA |
| Initial Operation Date | April 1988 |
| Last Update | Dec 2025 |
| Annual Generation | 6.9 GWh |
| Annual Consumption | 25.1 k MMBtu |
| Ranked #7,456 out of 13,081 Power Plants Nationwide | |
| Ranked #1,000 out of 1,311 Water Power Plants Nationwide | |
| Ranked #116 out of 131 Washington Power Plants | |
| Ranked #63 out of 70 Washington Water Power Plants | |
| Fuel Types | Water |
| Previous Operator |
Walla Walla City of (2013 to 2024) City of Walla Walla - (WA) (2025 to 2025) |
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Monthly Net Generation for Twin Reservoirs
Monthly Plant Fuel Consumption for Twin Reservoirs
Twin Reservoirs Details
| Summary Information | |
|---|---|
| Plant Name | Twin Reservoirs (50382) |
| Plant Address | 581 Mill Creek Road, Walla Walla, WA 99362 |
| Utility | City of Walla Walla - (WA) (20032) |
| Latitude, Longitude | 46.08833, -118.25472 |
| Generation Dates on File | Jan 2001 to Dec 2025 |
| Initial Operation Date | April 1988 |
| Annual Generation | 6.9 GWh |
| Fuel Types | Water |
| Federal Energy Regulatory Commission (FERC) Information | |
| FERC Cogeneration Status | No |
| FERC Small Power Producer Status | Yes |
| FERC Small Power Producer Docket Number | 86-342-000 |
| FERC Exempt Wholesale Generator Status | No |
| Regulatory Information | |
|---|---|
| Regulatory Status | Non-Regulated |
| NERC Region | WECC |
| Balancing Authority | Bonneville Power Administration (BPAT) |
| NAICS Code | Utilities (22) |
| Sector | IPP Non-CHP (2) |
| Water Source | Mill Creek |
| Ash Impoundment | No |
| Transmission / Distribution Owner | Columbia Rural Elec Assn, Inc (4041) WA |
| Grid Voltage | 14.40 kV |
| Energy Storage | No |
Generator GEN1 Details Operating April 1988
| Technology | Conventional Hydroelectric |
|---|---|
| Prime Mover | Hydroelectric Turbine |
| Ownership | Single Owner |
| Nameplate Capacity | 2.2 MW |
| Nameplate Power Factor | 0.9 |
| Summer Capacity | 1.8 MW |
| Winter Capacity | 1.5 MW |
| Minimum Load | 0.4 MW |
| Uprate/Derate Completed | No |
| Status | Operating |
|---|---|
| First Operation Date | April 1988 |
| Combined Heat & Power | No |
| Sector Name | IPP Non-CHP (2) |
| Energy Source | Water |
| Solid Fuel Gasification | No |
| Carbon Capture Technology | No |
| Time From Cold Shutdown To Full Load | 1H |
| Multiple Fuels | No |
Twin Reservoirs Plant Owners
| Owner Name | Address | Ownership | We couldn't locate any owners for this plant |
|---|
Power Plants with Similar Net Generation
Power plants with a similar annual net generation from Water.
| Rank | Plant Name | Plant Location | Annual Generation |
|---|---|---|---|
| #990 | Cobble Mountain | Granville, MA | 7.1 GWh |
| #991 | Mission | Murphy, NC | 7.0 GWh |
| #992 | Copenhagen Plant | Copenhagen, NY | 7.0 GWh |
| #993 | Oswegatchie | Edwards, NY | 7.0 GWh |
| #994 | Sibley Mill | Augusta, GA | 7.0 GWh |
| #995 | Schuylerville | Schuylerville, NY | 7.0 GWh |
| #996 | Dexter Plant | Dexter, NY | 6.9 GWh |
| #997 | Chester Diversion Hydroelectric Project | Chester, ID | 6.9 GWh |
| #998 | Peters Drive Plant | Hood River, OR | 6.9 GWh |
| #999 | Hydraulic Race | Lockport, NY | 6.9 GWh |
| #1001 | Messalonskee 2 (Oakland) | Oakland, ME | 6.8 GWh |
| #1002 | Sheep Creek Hydro | Northport, WA | 6.8 GWh |
| #1003 | Glenwood Hydro | Medina, NY | 6.7 GWh |
| #1004 | Pembroke Hydro | Suncook, NH | 6.7 GWh |
| #1005 | Strontia Springs Hydro Plant | Littleton, CO | 6.7 GWh |
| #1006 | Barber Dam | Boise, ID | 6.7 GWh |
| #1007 | Foothills Hydro Plant | Littleton, CO | 6.7 GWh |
| #1008 | Lundy | Lee Vining, CA | 6.7 GWh |
| #1009 | Hydro Plant | Three Rivers, MI | 6.7 GWh |
| #1010 | International Paper Woronoco Mill | Woronoco, MA | 6.6 GWh |
Nearby Power Plants
Below are closest 20 power plants surrounding Twin Reservoirs.
| Plant Name | Plant Location | Annual Generation | Distance |
|---|---|---|---|
| Chopin Wind LLC | Milton-Freewater, OR | 26.3 GWh | 17.5 mi |
| Combine Hills I | Milton-Freewater, OR | 61.2 GWh | 19 mi |
| Eurus Combine Hills Turbine Ranch 2 | Milton Freewater, OR | 137.0 GWh | 19 mi |
| FPL Energy Vansycle LLC (OR) | Touchet, OR | 225.1 GWh | 27.4 mi |
| FPL Energy Vansycle LLC (WA) | Touchet, WA | 249.7 GWh | 31.8 mi |
| Hopkins Ridge Wind | Dayton, WA | 352.9 GWh | 30.6 mi |
| Ice Harbor | Burbank, WA | 1.5 TWh | 31.9 mi |
| Little Goose | Dayton, WA | 1.6 TWh | 35.9 mi |
| Lower Monumental | Kahlotus, WA | 1.5 TWh | 35.5 mi |
| Lower Snake River Wind Energy Project | Pomeroy, WA | 802.3 GWh | 36.5 mi |
| Marengo Wind Plant | Dayton, WA | 612.6 GWh | 30.2 mi |
| McNary | Umatilla, OR | 4.0 TWh | 51.1 mi |
| McNary Dam Fish Attraction Project | Plymouth, WA | 72.5 GWh | 51.1 mi |
| Nine Canyon | Kennewick, WA | 185.8 GWh | 40.3 mi |
| Pilot Rock Solar 1 | Pilot Rock, OR | 410.0 MWh | 48.9 mi |
| Pilot Rock Solar 2 | Pilot Rock, OR | 340.0 MWh | 48.8 mi |
| Schumann Wind Farm | Milton-Freewater, OR | 23.1 GWh | 17.1 mi |
| Tucannon River Wind Farm | Dayton, WA | 736.8 GWh | 25.4 mi |
| Vansycle | Touchet, OR | 54.9 GWh | 22.1 mi |
| Vansycle II Wind Energy Center | Athena, OR | 320.1 GWh | 20.8 mi |