South Fork Tolt — Plant Summary
- EIA Plant ID
- 622
- Capacity
- 16.8 MW
- Primary Fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Status
- Operating
- Location
- King, WA
- Operating Since
- 1995
- Generators
- 1
- Operator
- City of Seattle - (WA)
- Parent Company
- —
- Annual Generation
- 44,630 MWh
- Capacity Factor
- 30.2%
- Balancing Authority
- Seattle City Light
- ISO/RTO
- —
- NERC Region
- WECC
South Fork Tolt
OperatingHydro
Ranked #43 of 75 Hydro plants in WA#515 of 1454 nationally
16.8 MW Hydro operating in King, WA — Seattle City Light
EIAWD
16.8 MW
Nameplate Capacity
1
Generators
unit
Conventional Hydroelectric
Technology
1995
Operating Since
Location
Coordinates
47.6993, -121.7834
County
King, WA
Nearby Plants
- Youngs Creek Hydroelectric ProjectHydro7.5 MW · 10.3 km
- Calligan Creek Hydroelectric ProjectHydro6 MW · 13.0 km
- Hancock Creek Hydroelectric ProjectHydro6 MW · 15.8 km
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | City of Seattle - (WA) | — | — |
| Owner(s) | City of Seattle - (WA) | — | — |
| Status | Operating | — | — |
Ownership Chain
No GEM tracker match for this plant — ownership chain unavailable.
About
South Fork Tolt is a 16.8 MW conventional hydroelectric power plant located in King County, Washington. The plant began operating in 1995 and has one generator. It is owned and operated by the City of Seattle. The plant's primary fuel source is water (WAT). South Fork Tolt is ranked 43rd out of 75 power plants in Washington state, and 524th out of 1464 nationally.
The plant operates within the Seattle City Light balancing authority and the Western Electricity Coordinating Council (WECC) NERC region. In the most recent year with available data, South Fork Tolt generated 44,630 MWh of electricity, achieving a capacity factor of 30.2%.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
Seattle City Light
Grid Voltage
115 kV
Regulatory Status
RE
Entity Type
Municipal
Sector
Electric Utility
Generation
3.2K MWh
Latest Month
44.6K MWh
Annual Generation
30.2%
Capacity Factor
Jan 2022 – Dec 2024
Financial Data
No financial data available for this plant.
Pricing & Market Data
Market Position
LMP Node
S_TOLT_1_GEN81GNODE
Pricing Hub
—
News & Articles (10)Beta
Hazards·flooding
Live updates: Tens of thousands still without power in Western Washington with more wind ahead
Flood waters are receding Thursday, but a flood watch remains in effect for several Western Washington counties. Meanwhile, farmers continue to assess...
KUOW·3 months ago
Hazards·flooding
King County executive issues emergency order as flooding forces evacuations, rescues
Residents near the Snohomish and Skagit rivers are facing the brunt of potentially "catastrophic" floods. See the latest weather forecasts,...
King County (other)
The Seattle Times·3 months ago
Hazards·flooding
Evacuations ordered across Western WA amid ‘catastrophic’ flooding
"Catastrophic" flooding is expected to hit parts of Skagit, Snohomish and King counties as rivers swell and the region is drenched in rain.
The Seattle Times·3 months ago
Grid·outage
More than 11,000 lose power as atmospheric river floods Western WA
More than 11000 customers in western Washington lost power late Monday as heavy rains and winds flooded the region.
MyNorthwest.com·3 months ago
Last updated 2026-03-26
View all 10 articles