How SF sources and uses water, and why it's pushing back on state restrictions

California is back in a drought, and in many parts of the state the drought is extreme. San Francisco’s residential water use is among the lowest among large cities in California, says Steven Ritchie, assistant general manager for water for the San Francisco Public Utilities Commission. He explains where the city gets its water from and how it's used, and why San Francisco is fighting state restrictions on the use of Tuolumne River water.