Cowlitz Falls — United States of America

Hydro power plant in Washington, United States of America. Approximate location 46.4661, -122.1097.

HydroWashingtonUnited States of America

Cowlitz Falls is a 70 MW hydro power plant in Washington, United States of America. It is operated by PUD No 1 of Lewis County. Based on reported annual generation of 165 GWh, it can supply roughly 47k homes. It ranks #3256 of 10,884 United States of America power plants by installed capacity. Commissioned in 1994, it is around 32 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 5.3% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).

70MW installed capacity
165GWh reported / yr
47,200homes powered
1994commissioned (~32 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0007427.

Data status

Known data

FacilityCowlitz Falls WRI
CountryUnited States of America · Washington WRI
Coordinates46.4661, -122.1097 WRI
FuelHydro WRI
MW installed capacity70 MW GEM · 2026 · L100001023304; operating plant capacity
Verification noteQuality label backfilled from existing source-backed capacity provenance on 2026-07-05; capacity value was not changed. source-verified
OwnerPUD No 1 of Lewis County WRI
Commissioned1994 WRI
GWh reported / yr165 GWh·a⁻¹ WRI

Calculated from dataset

Capacity rank in country#3256 / 10884 calculated
Fuel-specific rank in country#247 / 1449 calculated
Capacity vs country/fuel peers8.75× · 8 MW · n=1449 calculated
Homes-powered equivalent47,200 calculated from reported generation
Climate7.4°C · HDD 3,862 derived from coordinates
Environmental severityC3 · 25/100 derived from coordinates

Not available

TechnologyNot available not in dataset
CO₂ emissionsnot applicable not applicable

Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.

Data provenance

Source of the capacity and fuel values:

capacity: GEM · 2026 · L100001023304; fuel: WRI GPPD

In context: how this plant compares

At 70 MW, Cowlitz Falls is well above the median hydro plant in United States of America (8 MW). Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Key facts

Load factor
27%, from 165 GWh of reported generation; the median for 1342 hydro plants in United States of America that report generation is 42%
Generation trend
253 GWh in 2013 and 165 GWh in 2019 (−35%)
Highest and lowest year
2014: 290 GWh; 2019: 165 GWh
Share of United States of America hydro capacity
less than 0.1% of 102,513 MW across 1,449 plants in this dataset
Age among peers
1,328 of 1,444 dated hydro plants in United States of America are older

Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).

Reported generation trend

2013: 253 GWh20132014: 290 GWh20142015: 189 GWh20152016: 251 GWh20162017: 283 GWh20172018: 227 GWh20182019: 165 GWh2019290 GWh

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by PUD No 1 of Lewis County.

Local climate & thermal context

This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a warm-summer Mediterranean climate (Köppen Csb) — Northern Hemisphere, latitude 46.5°N — which shapes how much energy it can produce and how its output varies through the year.

7.4°Cannual mean temp
3,862heating degree-days (base 18°C)
0cooling degree-days (base 18°C)
886 melevation

Monthly mean temperature

J: 1 °CJF: 3 °CFM: 4 °CMA: 5 °CAM: 9 °CMJ: 12 °CJJ: 15 °CJA: 15 °CAS: 13 °CSO: 8 °CON: 4 °CND: 1 °CD15 °C

Heating degree-days here run 57% above the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.

Climate heat-demand index: 82/100 — this site sits in the top third of the power plants we cover by heating degree-days.

Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.

Site climate & environmental severity

This site sits in a moderately corrosive environment (estimated ISO 9223 class C3 — Medium), with humidity / wetness the leading environmental stress.

C3ISO 9223 corrosivity (indicative)
25/100environmental-severity index
14.4°Cseasonal temperature swing
149 kmdistance to coast

Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.

How it compares & nearby plants

The #247 largest hydro power plant of 1449 in United States of America by capacity.

United States of America has 1449 hydro power plants in this dataset, together about 102,513 MW of capacity.

Nearby power plants

  • Mossyrock · Hydro · 300 MW · Washington
  • Mayfield · Hydro · 162 MW · Washington
  • Alder · Hydro · 50 MW · Washington
  • Packwood · Hydro · 27.5 MW · Washington
  • LaGrande · Hydro · 64 MW · Washington
  • Swift 1 · Hydro · 240 MW · Washington

Location

Coordinates 46.4661, -122.1097 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Cowlitz Falls?

Cowlitz Falls is a 70 MW hydro power plant in Washington, United States of America, commissioned in 1994.

How much electricity does Cowlitz Falls generate?

Cowlitz Falls generates about 165 GWh of electricity per year.

Who operates Cowlitz Falls?

Cowlitz Falls is operated by PUD No 1 of Lewis County.

Built from open public data; no personal information. Operate this site? Request a correction or removal.