Located only 1,500 feet from the active Calaveras fault line in Santa Clara County, Calif., the Calaveras Dam could be in serious trouble if an earthquake were to hit. That’s why officials from the San Francisco Public Utilities Commission (SFPUC) lowered the water level of the Calaveras reservoir to less than 30 percent of its original volume in 2001 due to seismic concerns. But that reduction came at a price.
Calaveras Reservoir, impounded by Calaveras Dam, is the SFPUC’s largest drinking water reservoir in the local Bay Area. When it is full, it provides more than half of the Bay Area storage capacity for 2.6 million customers. The water supply is crucial during emergencies and times of drought, and with California in its fourth year of a record-breaking drought, the water is badly needed. The SFPUC was faced with an ultimatum: safety, or water?
