Data last collected:
PowerPlantFactsEvidence report · prepared 19 October 2026https://powerplantfacts.com/entity/3917
EIA plant 3917
Silver Creek · Lewis · WA
Mayfield
Operated by City of Tacoma - (WA)
Published location
Where is Mayfield?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
46.503500, -122.588500
Open the interactive map ↗Map data © OpenStreetMap contributors
Capacity is not generation. Nameplate MW describes equipment; annual MWh describes recorded output. Proposed and retired units are not added to operating capacity.
Equipment mix
Operating capacity by technology
Grouped from this plant’s represented generator records. Use the WA plant index for regional peers.
See the evidence
Electricity output across the year
Monthly net generation shows the seasonal shape of this plant's represented output. A negative value is retained when the source reports net consumption.
181,130
261,157
352,491
450,706
551,709
663,637
728,012
831,993
929,744
1033,374
1135,551
1256,850
MWh net generation · 2024 final edition · EIA 923 represented operating rows. 12 of 12 supplied rows shown; 0 missing values omitted. Months with no reported numeric value are omitted, not treated as zero.
Read the chart as a table
| Record | MWh net generation |
|---|---|
| 1 | 81,130 |
| 2 | 61,157 |
| 3 | 52,491 |
| 4 | 50,706 |
| 5 | 51,709 |
| 6 | 63,637 |
| 7 | 28,012 |
| 8 | 31,993 |
| 9 | 29,744 |
| 10 | 33,374 |
| 11 | 35,551 |
| 12 | 56,850 |
2024 monthly net generation
| Month | Net generation |
|---|---|
| 1 | 81,130 MWh |
| 2 | 61,157 MWh |
| 3 | 52,491 MWh |
| 4 | 50,706 MWh |
| 5 | 51,709 MWh |
| 6 | 63,637 MWh |
| 7 | 28,012 MWh |
| 8 | 31,993 MWh |
| 9 | 29,744 MWh |
| 10 | 33,374 MWh |
| 11 | 35,551 MWh |
| 12 | 56,850 MWh |
Operating generators
| ID | Technology | Fuel | MW | Status |
|---|---|---|---|---|
| 41 | Conventional Hydroelectric | WAT | 40.5 | OP |
| 42 | Conventional Hydroelectric | WAT | 40.5 | OP |
| 43 | Conventional Hydroelectric | WAT | 40.5 | OP |
| 44 | Conventional Hydroelectric | WAT | 40.5 | OP |
Continue exploring
Similar-capacity plants in the same state
Identity, technology and limitations
EIA plant ID
3917
Sector
Electric Utility
Water source
Cowlitz River
Data edition
2024-final
Use this record
Questions this evidence can answer
01What exactly is this record?
Use the name, place, date and identifiers above to confirm that you have the right Mayfield power plant: capacity and generation | PowerPlantFacts record.
02What does the evidence establish?
Read the reported values with their units, coverage dates and source notes. Keep observed facts separate from estimates or interpretation.
03What should I verify next?
Follow the primary-source links and check the limitations before using this evidence for a decision, comparison or citation.
A closer look at Mayfield
Variation in the published months
Across 12 numeric monthly generation entries, 1 has the highest recorded value (81,130 MWh) and 7 the lowest (28,012 MWh). Their difference is 53,118 MWh. Missing months have not been treated as zero.
Generator capacity in different operating conditions
| Generator ID | Technology | Nameplate MW | Summer MW | Winter MW | Minimum load MW |
|---|---|---|---|---|---|
| 41 | Conventional Hydroelectric | 40.5 | 41.0 | 41.0 | 8.0 |
| 42 | Conventional Hydroelectric | 40.5 | 41.0 | 41.0 | 8.0 |
| 43 | Conventional Hydroelectric | 40.5 | 41.0 | 41.0 | 8.0 |
| 44 | Conventional Hydroelectric | 40.5 | 41.0 | 41.0 | 8.0 |
EIA-860 2024 final source. Ratings describe capacity, not actual generation or availability. Missing ratings are not zero.
Source: US Energy Information Administration Form EIA-860 2024 plant and operable-generator workbooks; archive 2024. US EIA-authored information is generally public domain; cite EIA, preserve third-party exceptions, changes and no-endorsement context. Source-specific derived data.