We continue to hear that Hetch Hetchy Valley shouldn’t be restored because San Francisco’s water quality is exceptional. We have never believed this argument, but now we have evidence to back up our claim that San Francisco’s water quality, while good, is not truly special.
If you’re feeling a sense of déjà vu, you’re right – we wrote about this last November. We apologize for being repetitive, but this is an important message that bears repeating. Something that San Francisco officials and residents alike, as well as their wholesale customers need to hear. We will be sharing this information broadly and ask our supporters to do the same.
We are grateful to the University of Colorado Capstone Team for designing and initiating the taste test. And we are happy to collaborate with San Francisco or other parties who feel more research is warranted.
We are comfortable, however, with the results – that 75% of respondents favored either East Bay or Marin water over San Francisco water. The Bay Area Water Taste Test report. is included below and posted online. The complete report, with its five appendices, is posted online as well. Again, please share.
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Bay Area Water Taste Test
Restore Hetch Hetchy
July 2025
Overview
Restore Hetch Hetchy is committed to restoring the Hetch Hetchy Valley in Yosemite National Park while ensuring continued water and power reliability for all communities that rely on the Tuolumne River.
Some opponents and skeptics of restoration have asserted that the quality of San Francisco’s water is exceptional, and that the City’s residents and customers will be forced to drink inferior water when Hetch Hetchy Reservoir is relocated and Tuolumne River supplies are diverted from other locations.
Restore Hetch Hetchy agrees that San Francisco’s water is high quality, and we maintain it will still be good when Hetch Hetchy Valley is restored. We believe residents will experience no noticeable difference in water quality.
To test this assumption, we conducted taste comparisons between San Francisco’s water and other high-quality local supplies from the East Bay and Marin County. The results confirmed our expectations.
In a series of double blind taste tests, most respondents actually preferred East Bay and Marin water to San Francisco water. These findings indicate that water quality should not be a primary concern in debates over restoring the Hetch Hetchy Valley in Yosemite National Park.
Summary
In 2024, Restore Hetch Hetchy retained graduate students from the University of Colorado through its Capstone Program to design and initiate a double-blind water taste test to evaluate preferences of Bay Area residents.
In a series of trials conducted between June and October, the Capstone Team and Restore Hetch Hetchy asked participants to compare water supplies delivered by the San Francisco Public Utilities Commission (SFPUC, often colloquially called “Hetch Hetchy” water) with supplies delivered by the East Bay Municipal Utilities District (EBMUD) and the Marin Municipal Water District (MMWD). Participants ranked the taste of the three sources based on personal preference, with ties permitted.
A majority of participants preferred the taste of East Bay or Marin water to that of San Francisco. Out of 114 first place votes, 47 people (41%) selected East Bay water as best, 39 people (34%) selected Marin water as best, and 28 people (25%) selected San Francisco water as best. The results challenge the perception that ‘Hetch Hetchy’ water is superior. See Figure 1.
Methodology
The taste test took place in 3 phases:
In June, samples were collected at the SFPUC and EBMUD headquarters and from a Mexican restaurant in Larkspur (staff at the MMWD declined to provide samples for the test.). The University of Colorado Capstone Team, who designed the test, collected the opinions of passersby at the Rockridge BART station in Oakland. The Capstone Team’s Findings and their Methodology and Recommendations are included as Appendices A and B.
In July, samples were collected from private homes in San Mateo County (90% SFPUC water), Oakland (EBMUD) and Fairfax (Marin). The samples were offered to passersby at Safeway in Oakland and in private homes. These samples were also sent to Tap Score, an independent lab, for detailed analysis (see Appendices C (SFPUC), D (EBMUD) & E (MMWD).
In October, samples were collected from the same private homes in San Mateo County, Oakland and Fairfax. The water was offered to people attending Restore Hetch Hetchy’s Annual dinner on October 26 – as soon as they arrived and before they consumed any other food or beverage.
All testing followed a double-blind protocol: neither tasters nor test administrators knew which sample came from which source. Further, all taps were flushed before filling glass bottles, and all samples were kept at room temperature.
Testing and Results
A breakdown of the results from the separate trials reflecting the variability of responses is provided in Figure 2. Note that the exact mix of sources in any utility’s supply varies over time and location.[1]
Discussion
There are two fundamentally important aspects of water quality – health and taste. California’s large cities are fortunate that professional water agency staff regularly test and treat supplies, ensuring that their water is safe to drink.[2]
Water delivered in Marin, the East Bay and San Francisco is not only safe, but tastes good due to its modest mineral content. Water supplies in the East Bay and San Francisco primarily originate in the Sierra Nevada and are augmented by local rainfall and small amounts of groundwater. Water supplies in Marin come from local rainfall and groundwater, some of which is imported from Sonoma County.
Some water experts have indicated they prefer San Francisco’s water for its “pure” taste. Others prefer water with a slight mineral taste (mostly calcium and magnesium), suggesting that San Francisco’s water may be too neutral for their palate. Too much mineral content, as is the case with much of southern California’s water, is generally disfavored. Figure 3, below, compares the mineral content of the samples used in the taste tests with values reported in water supplies for San Diego, Los Angeles and Sacramento.
Conclusion
When Hetch Hetchy Valley is restored, San Francisco will still rely principally on the Tuolumne River for the majority of its supply. Water will be stored in and diverted from Cherry, Eleanor and/or Don Pedro Reservoirs – with mineral content perhaps similar to EBMUD’s Pardee Reservoir. Customers may like their water even better!
Restore Hetch Hetchy believes the reputation of ‘Hetch Hetchy’ water is overstated. We welcome opportunities to collaborate with the San Francisco Public Utilities Commission or other interested parties on future independent testing.
[1] On average, San Francisco derives 85% of its supply from the Tuolumne River. In recent years, however, the City has relied on local supplies and reservoirs in winter months so staff can do maintenance on the Mountain Tunnel – something customers rarely notice.
[2] Water in many small communities in California is not in fact safe to drink. See the Community Water Center for more information.
Diablo Grande is a small, recently built community of 1600 people, nestled in the hills on the west side of the San Joaquin Valley – about an hour’s drive southeast of Livermore. It’s fair to question the efficacy of building a town in that spot when urban or suburban infill might be a better approach for development in California.
The town, however, has been allowed to exist. What can and should it do to get water for its residents?
The verdant landscape surrounding Diablo Grande will turn brown during hot summer months, but the community apparently hoped to irrigate the thirsty and fast growing redwoods to provide protection from the hot sun and wind.
Small communities having water supply issues is a familiar story for many of us. But does it make sense, especially since Diablo Grande is only 5 miles from the California Aqueduct?
Unlike almost any other commodity, however, water is not simple to buy and sell. California has a cattywampus water rights system and agencies collectively hoard the essential liquid. Development of Diablo Grande was initially disallowed for lack of water supply, then permitted when the community formed a water agency and contracted to purchase water from the Kern County Water Agency (Kern’s water is not conveyed from hundreds of miles away, rather moved only 5 miles uphill from the California Aqueduct, slightly lessening the supplies transported from the Delta to Kern County under its contract with the State Water Project.).
Diablo Grande is only 5 miles as the crow flies from the California Aqueduct which carries millions of acre-feet annually from the Delta to farms in the San Joaquin Valley and cities in Southern California.
But they seemed to forget to pay for the water. Kern had planned to cut Diablo Grande off, then agreed to provide water if residents agree to pay $569 per month – a 300% increase over the previous water rates.
Residents blame the bankrupt developer. Those of us who follow water closely might have realized that a short-term water transfer contract with the Kern County Water Agency does not have the security of a long-term contract with the State Water Project. But most people are unaware – they turn on their tap and expect water to flow.
Why is it that a community like Diablo Grande has so few options when there is so much water nearby? Why aren’t other sellers ready to do business? Why is there such a water shortage when there is no drought (fingers crossed)?
There is no such thing of a milk shortage, an electricity shortage or a sneaker shortage in small towns, as long as residents are able and willing to pay for them. Why is water different?
Water rights are controlled by urban and agricultural agencies, and marketing of water between them is highly regulated and very often discouraged by parochial interests that prevent water from being used efficiently.
Diablo Grande’s woes may garner little sympathy. But the fiefdoms that control California’s water have also caused San Francisco to overinvest in storage – a significant cost to its ratepayers.
San Francisco’s nine reservoirs, including Hetch Hetchy Reservoir, hold more that 6 times its annual use. The reason for such a conservative approach is not that anyone thinks there will be zero rain for 6 years. But they do fear that there could be drought – little rain for 6 years – and almost all of the Tuolumne River’s flow would belong to the Turlock and Modesto Irrigation Districts under their senior water rights leaving San Francisco with its junior water rights dry. In a sane world cities like San Francisco would simply pay a slightly higher price during droughts to purchase water from others rather than having to invest in excess storage that provides so little economic return.
For more on California’s cattywampus water policies (apologies for the technical term), see our blogs on water rights and water prices.
Restore Hetch Hetchy firmly believes better water markets could help solve California’s water woes as well as making it easier to restore Hetch Hetchy.
Markets are not, however, a panacea. Basic human needs for everybody as well as the public trust (streams, wetlands etc.) should be protected from market forces. Most business uses, including agriculture, and discretionary urban use, however, would be more efficient with market mechanisms at play.
By improving efficiency in cities and on farms, economic incentives will help maximize food production and meet business needs while optimizing the use of limited water supplies. As a result, it will be easier to meet those basic human needs and to reduce the pressure to extract ever increasing amounts of water from our rivers and streams.
Hooray, after only 114 years (sarcasm fully intended), San Francisco will be providing drinkable water to the campground at Hetch Hetchy!
The project will provide water to the National Park Service office as well as to the campground. San Francisco notes that geotechnical analysis is required before drawings can be completed and a contract can be advertised. They hope to start construction in fall 2026 and complete the project by summer 2027.
This development comes as a direct result of the petition Restore Hetch Hetchy filed with the National Park Service and Department of the Interior in 2023.
Section 9(p) of the 1913 Raker Act reads in part “The said grantee shall further lay and maintain a water pipe, or otherwise provide a good and sufficient supply of water for camp purposes at the Meadow, one-third of a mile, more or less, southeasterly from the Hetch Hetchy Dam site.”
Presently, potable water is available 1/2 mile away near the cabins reserved for San Francisco’s elite guests.
It’s hard to comprehend why neither San Francisco nor the National Park Service saw fit to implement this provision of the Raker Act until now. The requirement couldn’t be clearer and we are happy to see it finally being enforced.
Other intentions of the Raker Act – including camping, lodging and boating – are not as clearly prescribed in the statutory provisions. Presently, only those leaving for or returning from a backpacking trip are allowed to use the campground. Restore Hetch Hetchy intends to work cooperatively with the National Park Service and others to ensure that the campground is available to all – and that the campground gets a sorely needed makeover as well.
We haven’t forgotten about other important upgrades to the visitor experience at Hetch Hetchy, including:
San Francisco’s recreational use of the “chalet” and bunkhouses for its elite guests does not comport with the Raker Act’s instructions that authorizes only structures or buildings necessary or properly incident to the construction, operation, and maintenance of said water-power and electric plants. If these buildings are used for recreation, they should be available to all park visitors.
We also continue to advocate for boating and fishing as discussed at length by Congress prior to the Raker Act’s passage but not mentioned in the act itself. 37 of the 38 reservoirs in California holding more than 200,000 acre-feet of water allow these activities – only Hetch Hetchy does not!
There’s an irony that Restore Hetch Hetchy advocates for minor infrastructure as we campaign to eliminate the wholly unwarranted and inappropriate reservoir made possible by the O’Shaughnessy Dam. We pledge that, when Hetch Hetchy is restored to its natural splendor, minimal infrastructure will be constructed, welcoming visitors but preventing the gridlock that too often besets Yosemite Valley.
Yosemite’s Hetch Hetchy Valley lies underwater. Our mission is to relocate the reservoir so we can return the Hetch Hetchy Valley in Yosemite National Park to its natural splendor ─ while continuing to meet the water and power needs of all communities that depend on the Tuolumne River.
This week we are sharing America’s Lost National Park by Aidin Robbins, a film that has received more than 400,000 views since it was posted just 2 weeks ago. Robbins describes Hetch Hetchy as what “just might be the most important landscape in the United States”.
Robbins expertly weaves the story of Hetch Hetchy – its damming and the aftermath (the National Park Service Act and rejections of proposed dams in Yellowstone, Glacier and Grand Canyon). The Hetch Hetchy experience helped our nation to take our parks seriously and to avoid further such damage. Please check out Robbins’ film.
And, as of Saturday evening, there is good news.
Senator Mike Lee of Utah, the chief proponent for the sale of public lands as part of President Trump’s “Big Beautiful Bill”, has withdrawn his proposal!
Montana Congressman and former Secretary of the Interior Ryan Zinke led a group of 5 Republican members of the House of Representatives who committed to voting against the bill if it included any sale of public lands. Zinke’s op ed in the Washington Examiner is here (subscription required).
While the Big Beautiful Bill did not threaten our national parks per se, Restore Hetch Hetchy agrees with Rep Zinke – once lands are gone, they are gone forever. They should not be sold.
It’s always nice when folks support restoration of Hetch Hetchy Valley in Yosemite National Park – even if their approach is a bit different from ours. San Francisco, as expected, continues with its own propaganda which ignores its destruction of the iconic landscape.
Edward Ring’s “The Hypocrisy of San Francisco’s Hetch Hetchy Reservoir“, was published June 20th by “American Greatness”. The column is extremely critical of San Francisco – accusing the City of “self-congratulatory, performative environmentalism.”
We agree entirely with Ring when he writes “We can argue, and should, over what role environmentalism should play in the 21st century and how we can best balance the legitimate concerns over sustainability and ecosystem preservation with economic health and human prosperity. But there is one thing we ought to agree on: the water that serves San Francisco today, quenching the thirst of a population with probably the highest percentage of serious and committed environmentalists in the world, is the result of an abomination that broke John Muir’s heart.” We are less certain when he bashes the City’s other environmental commitments.
Jessie Dickson, aka “SacramentoFoodForest”, posted a strident video on Instagram which received more than 72,000 ” likes” and 4000 comments! The video declares that it’s time for San Francisco to find a new water source and describes Hetch Hetchy as “the original public land grab in the United States.”
Sacramentofoodforest describes damming Hetch Hetchy as a crime against Mother Nature.
Dickson/SacramentoFoodForest goes on to say damming Hetch Hetchy was “a crime against Mother Nature”, that it was “a biodiversity hotspot with grasslands old growth forests and a river fed by countless waterfalls” and that it “should have been protected since it’s part of a national park.” The City “needs to remove the O’Shaughnessy Dam and free Yosemite Valleys twin.”, Jessie concludes.
Even if San Francisco continues to resist restoration, it would be nice if it conceded that damming Hetch Hetchy Valley buried a spectacular landscape – something the SF Public Utilities Commission seems to want us to forget
Restore Hetch Hetchy, on the other hand, is always prepared to engage in substantive discussion of the merits of restoration as well as its challenges.
