ROCK ISLAND

How ROCK ISLAND compares

With 629 MW of capacity, ROCK ISLAND ranks 14th among the 126 operating power plants Bywatts maps in Washington and 11th of the 65 operating Hydro plants in the state. It accounts for about 3.0% of Washington's operating Hydro capacity and 2.1% of all operating capacity in the state. Nationally it is the 34th-largest of the 1,243 operating Hydro plants in the database. Commissioned in 1931, it is older than 87% of the 125 operating Washington plants with a recorded commissioning year. Its operator, PUD NO 1 OF CHELAN COUNTY, runs 3 operating plants in Washington totaling 1,988 MW. It shares Chelan County with 3 other operating plants, including ROCKY REACH and WELLS.

EIA-860 lists 19 generators at the site with 629 MW of nameplate capacity, all conventional hydroelectric technology. Net generation was 2,025 GWh in 2024 (a 37% capacity factor), down 22% from 2022. Its generators came online between 1931 and 1979.

Grid neighborhood

The nearest named substation is MCKENZIE SWITCHYARD (230 kV), about 1.7 miles away; the closest transmission line found within 10 miles is a 115 kV line owned by PUD NO 1 OF CHELAN COUNTY, under 0.1 miles away. Another 3 operating power plants totaling 1,582 MW sit within 25 miles; the largest is ROCKY REACH (1,300 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