Where Are Hydroelectric Plants in the United States?

Hydroelectricity provides ~6% of US electricity but ~90% of renewable generation (pre-wind/solar boom). Plants cluster where topography and hydrology align:

1. Pacific Northwest: The Hydro Heartland

Columbia River Basin (WA, OR, ID, MT). Grand Coulee Dam (6,809 MW – largest US plant), Chief Joseph, John Day, The Dalles, Bonneville, McNary, Ice Harbor, Lower Monumental, Little Goose, Lower Granite. + Snake River dams. Massive output, salmon conflicts.

2. California: Sierra Nevada & Beyond

• Central Valley Project / State Water Project: Shasta Dam (Sacramento R.), Oroville Dam (Feather R.), Folsom Dam (American R.).
• Colorado River: Hoover Dam (NV/AZ border – 2,080 MW), Parker, Davis, Imperial dams.
• High Sierra: Helms Pumped Storage (1,212 MW), Big Creek system (SCE).

3. New England: Fall-Line & Mountain Power

• Maine: Penobscot, Kennebec, Androscoggin rivers (many medium dams).
• Vermont/New Hampshire: Connecticut River (Fifteen Mile Falls, Moore, Comerford).
• Massachusetts: Connecticut, Merrimack, Deerfield (pumped storage: Bear Swamp).

4. Tennessee Valley Authority (TVA) System

9 main-river dams + 4 tributary dams. Norris, Wheeler, Guntersville, Wilson, Pickwick, Kentucky, Fontana, Douglas, Cherokee. Multi-purpose: power, flood control, navigation, recreation.

5. New York: Niagara & St. Lawrence

• Niagara Falls: Robert Moses Niagara (2,675 MW) & Lewiston Pump-Gen (240 MW) – largest single-site in NY.
• St. Lawrence River: St. Lawrence-FDR (Moses-Saunders, 912 MW) (shared with Canada).

6. Southeast: Fall Line & Reservoirs

Chattahoochee (GA/AL: Buford, West Point, Walter F. George), Savannah (GA/SC: Hartwell, Russell, Thurmond), Santee-Cooper (SC), Cumberland (TN/KY: Wolf Creek, Center Hill).

7. Southwest: Colorado River Storage Project

Glen Canyon Dam (Lake Powell, 1,320 MW), Flaming Gorge, Blue Mesa, Morrow Point, Crystal, Navajo. Critical for water + power.

8. Other Notable Clusters

• Missouri River Mainstem Dams (MT, ND, SD, NE): Fort Peck, Garrison, Oahe, Big Bend, Fort Randall, Gavins Point.
• Pacific Islands: Hawaii (Wailua, Waimea), Guam, Puerto Rico (Caonillas, Dos Bocas).

Total: ~2,300 hydro plants (FERC licensed), but top 50 produce 80% of output.