Geography-bound · 2025

Hydroelectric Energy

Electricity reported from conventional hydroelectric generators, excluding pumped storage.

Washington
Geographic lead
47
States with output
247.0M MWh
US generation · 2025
3%
Median own-mix share (positive states)

Verify with EIA → · Methodology

Washington holds 26% of U.S. hydroelectric

According to the U.S. Energy Information Administration (EIA State Electricity Profiles, 2025), Hydroelectric generated 247.0M MWh of U.S. electricity across 47 states, led by Washington at 26% of the national total. Hydroelectric supplies 63.6% of Washington's own electricity mix.

Operating fleet · May 2026

Largest plants with operating hydroelectric units

EIA lists 1,349 plants with 75,229.5 MW of operating summer capacity in the matched hydroelectric categories. The table shows the 30 largest plants after combining their matched generator units.

Scroll horizontally for state, technology, and capacity.

Plant Reported operator State Technology Summer capacity
Grand Coulee U S Bureau of Reclamation Washington Conventional Hydroelectric 6,765 MW
Robert Moses Niagara New York Power Authority New York Conventional Hydroelectric 2,434.9 MW
Chief Joseph USACE Northwestern Division Washington Conventional Hydroelectric 1,743.8 MW
John Day USACE Northwestern Division Oregon Conventional Hydroelectric 1,417 MW
Glen Canyon Dam U S Bureau of Reclamation Arizona Conventional Hydroelectric 1,312 MW
Rocky Reach PUD No 1 of Chelan County Washington Conventional Hydroelectric 1,253.9 MW
Wanapum PUD No 2 of Grant County Washington Conventional Hydroelectric 1,220 MW
The Dalles USACE Northwestern Division Oregon Conventional Hydroelectric 1,208.7 MW
Boundary City of Seattle - (WA) Washington Conventional Hydroelectric 1,144.9 MW
Hoover Dam (AZ) U S Bureau of Reclamation Arizona Conventional Hydroelectric 1,039.7 MW
Hoover Dam (NV) U S Bureau of Reclamation Nevada Conventional Hydroelectric 1,039.4 MW
Bonneville USACE Northwestern Division Oregon Conventional Hydroelectric 971.7 MW
Priest Rapids PUD No 2 of Grant County Washington Conventional Hydroelectric 950 MW
McNary USACE Northwestern Division Oregon Conventional Hydroelectric 850.5 MW
Robert Moses Power Dam New York Power Authority New York Conventional Hydroelectric 802.5 MW
Wells PUD No 1 of Douglas County Washington Conventional Hydroelectric 796 MW
Oahe USACE-Omaha South Dakota Conventional Hydroelectric 714 MW
Shasta U S Bureau of Reclamation California Conventional Hydroelectric 714 MW
Brownlee Idaho Power Co Idaho Conventional Hydroelectric 702.4 MW
Lower Monumental USACE Northwestern Division Washington Conventional Hydroelectric 675 MW
Wilson Dam Tennessee Valley Authority Alabama Conventional Hydroelectric 667.5 MW
Lower Granite USACE Northwestern Division Washington Conventional Hydroelectric 667 MW
Noxon Rapids Avista Corp Montana Conventional Hydroelectric 580.7 MW
Little Goose USACE Northwestern Division Washington Conventional Hydroelectric 540 MW
Big Bend Dam USACE-Omaha South Dakota Conventional Hydroelectric 520 MW
Garrison USACE-Omaha North Dakota Conventional Hydroelectric 510 MW
Conowingo Constellation Power, Inc Maryland Conventional Hydroelectric 496.9 MW
Dworshak USACE Northwestern Division Idaho Conventional Hydroelectric 465 MW
Hells Canyon Idaho Power Co Oregon Conventional Hydroelectric 453.1 MW
Ross City of Seattle - (WA) Washington Conventional Hydroelectric 450 MW

Capacity is not generation: it describes the rated operating fleet, while the state table reports electricity actually generated during 2025.

26%

national total in the lead state

47

states with any hydroelectric output

3%

median own-mix share among positive states

Washington

geographic lead (63.6% of its mix)

Hydroelectric Generation by State

Rank State Generation (MWh) Share of State Mix
#1 Washington 65.2M
63.6%
#2 Oregon 29.2M
45.2%
#3 California 27.9M
11.7%
#4 New York 25.8M
18.9%
#5 Montana 9.8M
34.2%
#6 Idaho 9.7M
47.2%
#7 Tennessee 8.4M
11.2%
#8 Alabama 8.3M
6.0%
#9 Arizona 4.9M
4.0%
#10 South Dakota 4.9M
22.0%
#11 North Carolina 4.6M
3.4%
#12 Kentucky 3.9M
5.3%
#13 Arkansas 3.2M
4.8%
#14 Georgia 3.0M
2.1%
#15 Pennsylvania 2.7M
1.1%
#16 Maine 2.6M
18.2%
#17 South Carolina 2.5M
2.4%
#18 North Dakota 2.2M
5.2%
#19 Wisconsin 2.2M
3.3%
#20 Nevada 1.9M
4.0%
#21 Colorado 1.9M
3.1%
#22 Alaska 1.8M
28.8%
#23 Oklahoma 1.7M
1.9%
#24 Maryland 1.6M
4.0%
#25 New Hampshire 1.4M
7.1%
#26 Michigan 1.3M
1.1%
#27 West Virginia 1.3M
2.4%
#28 Nebraska 1.3M
3.1%
#29 Texas 1.2M
0.2%
#30 Virginia 1.2M
1.2%
#31 Vermont 1.2M
58.2%
#32 Iowa 1.1M
1.5%
#33 Wyoming 1.1M
2.4%
#34 Missouri 1.0M
1.4%
#35 Minnesota 921.2K
1.5%
#36 Louisiana 837.3K
0.8%
#37 Utah 827.6K
2.2%
#38 Massachusetts 827.3K
3.0%
#39 Ohio 432.9K
0.3%
#40 Indiana 351.9K
0.3%
#41 Connecticut 342.1K
0.8%
#42 New Mexico 184.8K
0.5%
#43 Florida 165.3K
0.1%
#44 Illinois 89.3K
0.0%
#45 Hawaii 82.2K
0.7%
#46 Kansas 23.3K
0.0%
#47 New Jersey 6.3K
0.0%

Hydroelectric generation leaders (2025)

Net generation in terawatt-hours (TWh), from EIA State Electricity Profiles.

TWh
  • Washington
    65
  • Oregon
    29
  • California
    28
  • New York
    26
  • Montana
    10
  • Idaho
    10
  • Tennessee
    8
  • Alabama
    8
  • Arizona
    5
  • South Dakota
    5
Source EIA State Electricity Profiles As of 2025

Frequently Asked Questions

How geographically concentrated is hydroelectric generation? ▼
Washington alone reports 26% of U.S. hydroelectric generation in 2025, and hydroelectric is 63.6% of that state's own mix. Only 47 jurisdictions report positive output.
What does hydroelectric operating capacity mean here? ▼
The 2026-05 EIA inventory reports 75.2K MW of net summer capacity across 1,349 plants in the categories used on this page. Capacity is not converted into generation on this page.
Where does RateWatt's hydroelectric data come from? ▼
Generation comes from EIA State Electricity Profiles (2025). Operating-plant capacity comes from the separate EIA operating-generator inventory (May 2026). Neither series is a retail-rate or customer-delivery measure.

Reading the hydroelectric numbers

Hydroelectric is geography-bound, a handful of states dominate national totals while many report none.

Generation mix is not the same as the electricity a state consumes; surplus is traded across the grid. See our methodology.

Related guide

Renewable vs Fossil Fuel Costs

LCOE assumptions and cited technology comparisons

Where these figures come from

Generation and capacity are separate EIA series with separate vintages; neither is a retail-rate or customer-delivery measure.

Generation: U.S. Energy Information Administration (2025) · operating capacity inventory: 2026-05.
All federal data sources used on this page

Generation totals on this page come from EIA State Electricity Profiles for 2025; operating-plant capacity comes from the separate EIA operating-generator inventory (May 2026). No figure is typed in by an editor. State shares are generation_mwh for this source ÷ state total generation in the same profile year. Plant rows sum only units whose EIA energy-source/technology labels match this profile's allowlist. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2025.

Sources: EIA State Electricity Profiles and EIA Operating Generator Capacity. See our methodology.