By the numbers

  Amid four years of drought, reservoir levels have plunged across California. These dams are typically a small but important producer of power. Reservoir levels at some major California dams: Shasta: 50% Trinity: 36% Folsom: 54% New Melones: 8% Californians are less reliant on hydropower than in previous decades. The percentage of the state's energy supply that comes from hydropower: 1950s: 60% Today: 14% to 19% Source: U.S. Bureau of Reclamation, California Energy Commission