(First in Series of stories supplementing the upcoming public television documentary)

Every drop of water we use in the San Francisco Bay Area, to shower, bathe, or quench our thirst, travels to our faucets through one of the most amazing systems of engineering known to man.

Have you ever wondered how it gets from Hetch Hetchy to our homes? What would happen if suddenly we found ourselves without access to clean water? Between recurring droughts, climate change and a growing population, what is San Francisco doing to insure we have a continuous flow of water into the future?

Did you know our sparkling City by the Bay began as sand dunes before becoming the jewel of California? Are you curious how water reaches us every time we turn on the tap? Or, what San Francisco is doing to make sure we have a continuous flow into the future?

The story of how O’Shaughnessy Dam came to be built in the years after the 1906 earthquake and fire, is the subject of a new documentary “Water From the Wilderness”, produced by Jim Yager Media. The documentary explores San Francisco’s water future in light of climate change, a growing population and an aging infrastructure.

Since 1934, Hetch Hetchy has been the source of clean water for the San Francisco Bay Area. Here are a few facts you may not have known about this engineering marvel.

Here are eight facts about our water to think about the next time you turn on the tap:


In 1923 the O’Shaughnessy Dam opened, holding back the Tuolumne River, flooding Hetch Hetchy Valley. In the 1930’s it was raised another 80 feet, and the gravity arch now stands at 364 feet high and is constructed with over 662,000 cubic yards of concrete – making it one of the largest civic engineering feats of that era.


The system, spanning 167 miles from Yosemite to San Francisco, took 21 years to build. City Engineer Michael Maurice O’Shaughnessy asked voters to approve 5 different bond measures to ensure its completion – earning him the nickname “More Money O’Shaughnessy”. On October 24th, 1934, at a grand opening celebration at the Pulgas Water Temple on the southern end of Crystal Springs reservoir, the first waters from Hetch Hetchy finally reached the San Francisco.


Hetch Hetchy Reservoir in Yosemite National Park provides water to over 2.6 million people in 29 cities in the San Francisco Bay Area. The water, provided by snowmelt via the Tuolumne River, does not require filtration.



The Tuolumne river provides great drinking water because of the lack of mining in the area. The water is pure, and the granite basin helps clean sediment from the water allowing it to be delivered unfiltered.


It is one of the few surface water sources in the U.S. that can be legally delivered unfiltered to customers, although it is disinfected prior to delivery for public health.



The Hetch Hetchy Aqueduct is a canal or series of large pipes that connect the source of water to its various City destinations. The entire system, as designed by O’Shaughnessy is gravity fed – flowing downhill from Yosemite – and requires no pumping to reach Crystal Springs. There are 85 miles of tunnels, some of them through solid granite and another 71 miles of pipelines.


Over 31,900,000 cu ft (900,000 m3) of water per day, is delivered to residents of San Francisco, San Mateo, Santa Clara, and Alameda Counties. That is approximately 265,000 acre-feet (327,000 dam3) of water delivered each year.


Since the dam was completed, the water system has been providing some of the cleanest, and to some, the best tasting water in the nation to the population of San Francisco and surrounding cities, currently over 2.6 million users.

Hetch Hetchy has been providing the Bay Area with a clean source of drinking water for nearly a century, reshaping the San Francisco Bay area into the cosmopolitan region it is today. But with climate change its future is far from certain. Look for our public television documentary “Water from the Wilderness” this spring and the story of how the City by the Bay is meeting these challenges head on.

Coming Spring 2018
Water From The Wilderness: From Hetch Hetchy To San Francisco Bay
Produced by Jim Yager Media

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