DIABLO

How DIABLO compares

With 182 MW of capacity, DIABLO ranks 33rd among the 126 operating power plants Bywatts maps in Washington and 17th of the 65 operating Hydro plants in the state. It accounts for about 0.9% of Washington's operating Hydro capacity and 0.6% of all operating capacity in the state. Nationally it is the 96th-largest of the 1,243 operating Hydro plants in the database. Commissioned in 1936, it is older than 84% of the 125 operating Washington plants with a recorded commissioning year. Its operator, CITY OF SEATTLE - (WA), runs 7 operating plants in Washington totaling 1,929 MW. It shares Whatcom County with 9 other operating plants, including ROSS and FERNDALE GENERATING STATION.

EIA-860 lists 4 generators at the site with 182 MW of nameplate capacity, all conventional hydroelectric technology. Net generation was 361 GWh in 2024 (a 23% capacity factor), down 39% from 2022. Its generators came online between 1936 and 1937.

Grid neighborhood

The nearest named substation is DIABLO (230 kV), under 0.1 miles away; the closest transmission line found within 10 miles is a 230 kV line owned by CITY OF SEATTLE - (WA), under 0.1 miles away. Another 3 operating power plants totaling 660 MW sit within 25 miles; the largest is ROSS (450 MW, Hydro).

Computed by Bywatts from HIFLD power plant, substation and transmission line records and EIA-860/923 survey data; distances are straight-line. Sources and methodology