Cowlitz Falls

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 47,200 homes. It ranks #2387 of 9,833 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.

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.

In colder climates, uninsulated hot equipment (boilers, turbines, valves, steam lines) loses proportionally more heat to ambient air — exactly the loss Inzonex modular insulation is designed to cut.

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.

How it compares & nearby plants

The #245 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 101,657 MW of capacity.

Nearby power plants

Location

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

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