The Cleaner, Greener, More Affordable Water Cooler for San Francisco

When early settlers came to the Bay Area, they discovered a plethora of artesian aquifers. But when the Gold Rush hit, the influx of fortune seekers depleted San Francisco’s water supply. Its new residents also dumped waste into local creeks and streams, forcing the city to import water from outside the city.

In 1860, the newly chartered Spring Valley Water Company dug wells in the farm districts of East Bay, damned a coastal stream to fill a wooded watershed, and then built a 32-mile flume to deliver water north to San Francisco. However, the Great 1906 Earthquake destroyed the above-ground aqueduct system along with 80% of the city’s structures.

The engineers charged with rebuilding San Francisco needed to find a more secure way to provide water. City planners thought to dam the Tuolumne River in the Hetch Hetchy Valley in the northwestern part of the Yosemite National Park. After a decade-long battle with the Federal government and an act of Congress, San Francisco gained permission to build the O’Shaughnessy Dam.

Upon completion of the dam in 1923, the Hetch Hetchy Valley was flooded. The dam and gravity-fed system successfully began delivering virgin snowmelt from the Sierra Mountains to residents of San Francisco 148 miles away.

Today, San Francisco represents California’s third largest utility, serving over 2.7 million people in the Bay Area. The city sources water from surface water stored in reservoirs located in the Sierra Nevada, Alameda County, and San Mateo County, and groundwater stored in a deep aquifer located in San Francisco and San Mateo counties.

According to a recent San Francisco Water Quality report,  open surface water reservoirs are prone to runoff, which contaminates San Francisco drinking water with chemicals inorganic and organic particles, and bacteria. California frequently experiences periods of drought, and many San Francisco residents experience water quality issues, like an increase in total dissolved solids, chlorine, and nitrates in their drinking water.