Approximately 20% of California’s energy usage goes to moving water. Three-quarters of California’s water comes from the northern third of the state, and most Californians live in the dry, southern two-thirds of the state. So that water has to be moved through one of the most complex civil engineering projects in history: the State Water Project and the Central Valley Project. Moving all of this water across the state requires an enormous amount of energy. Electric pumps at the base of the Tehachapi Mountains that move water into southern California use about four billion kilowatt-hours of energy per year; that’s enough to power the entire city of Los Angeles for two months.