Hydropower's share of electricity generated in Washington, 2001-2025

What this chart asks

Has hydropower supplied most of the electricity generated in Washington each year, and how far did the share fall in the 2023-2024 drought?

Why it is shown this way

• A line shows the year-to-year path of a single annual share; each point is one calendar year placed on January 1.
• The y axis starts at zero so the size of the hydro share and of its drops is not exaggerated.
• A 50 percent reference line marks the threshold for "most" so readers can see the share stayed above it every year.

Chart annotations

These markers provide relevant context for interpreting the chart. Their timing or position does not, by itself, establish causation.

50% (half of generation)

Threshold: 50

Reference line for "most". Editorial, not a data value.

Why this is marked: The claim being checked says hydro supplies "most" of Washington's electricity, so the 50 percent line is the test.

2023-24 drought

January 1, 2023–December 31, 2024

Washington declared drought emergencies in 2023 (12 watersheds) and 2024 (most of the state); hydro fell to 59.7% and 59.3% of generation, the lowest in the series.

Data and accessibility

Download chart data · Open accessible table · Download PNG · Download SVG

Dataset wa-electricity-generation-by-source, analysis wa-hydro-share-annual

Sources

This chart draws on the sources of the dataset versions it visualizes.

Washington Electricity Generation by Source and the Largest U.S. Power Plants, 2001-2025

1. U.S. Energy Information Administration, State Historical Tables: Net Generation by State by Type of Producer by Energy Source, 1990-2025 (Final, released September 2026) Primary source for annual Washington net generation by energy source and for the state hydro ranking (EIA-923 and predecessor forms).

   Retrieved October 9, 2026. U.S. federal government work (public domain). Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

2. U.S. Energy Information Administration, State Electricity Profile tables for Washington (data year 2024) Table 10 (supply and disposition: retail sales, international trade, net interstate trade) and cross-check of Table 5 generation totals.

   Retrieved October 9, 2026. U.S. federal government work (public domain). Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

3. U.S. Energy Information Administration, Form EIA-860 Annual Electric Generator Report, 2025 final data (eia8602025.zip, file 3_1_Generator_Y2025.xlsx, sheet Operable) Generator-level nameplate, summer and winter capacity used to rank U.S. plants by capacity.

   Retrieved October 9, 2026. U.S. federal government work (public domain). Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

4. U.S. Energy Information Administration, Form EIA-923 Power Plant Operations Report, 2025 final data (f923_2025.zip, Schedules 2-5, Page 1 Generation and Fuel Data) Plant-level 2025 net generation used to rank U.S. plants by annual output.

   Retrieved October 9, 2026. U.S. federal government work (public domain). Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

5. Washington State Department of Commerce, Fuel Mix Disclosure Consumption-side check: the aggregate 2024 fuel mix of electricity Washington utilities reported delivering to Washington customers.

   Retrieved October 9, 2026. Washington State public record. Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

6. Washington State Department of Commerce, chart "Washington electric utilities aggregate 2024 fuel mix" (image on the Fuel Mix Disclosure page) The labeled percentages transcribed into the wa-utility-fuel-mix-2024 table.

   Retrieved October 9, 2026. Washington State public record. Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

7. U.S. Bureau of Reclamation, Grand Coulee Dam: About Operator statement of Grand Coulee generating capacity (6,809 MW) and typical output (up to 21 billion kWh), used as a replication check.

   Retrieved October 9, 2026. U.S. federal government work (public domain). Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

8. U.S. Energy Information Administration, Today in Energy, "Drought conditions reduce hydropower generation, particularly in the Pacific Northwest" (November 7, 2024) Context on 2023-2024 Pacific Northwest hydro conditions; states Grand Coulee net summer capacity as 6.7 GW.

   Retrieved October 9, 2026. U.S. federal government work (public domain). Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

9. Washington State Department of Ecology, news release, April 16, 2024 drought declaration Dates the 2024 statewide drought emergency and the 2023 emergency covering 12 watersheds.

   Retrieved October 9, 2026. Washington State public record. Linked as a public record; the source file is not redistributed. Its SHA-256 is recorded here and in source-manifest.json.

   Archived copy captured October 9, 2026

Limitations

• Shows electricity generated by plants in Washington, not the mix of electricity Washington customers bought; Washington utilities reported 48.73% hydro in their 2024 delivered fuel mix (see the dataset's wa-utility-fuel-mix-2024 analysis).
• Annual totals hide seasonal swings in hydro output.
• Conventional hydro only; pumped storage is excluded.