Ecological rewind

Environmentalists want to tear down O'Shaughnessy Dam and restore the Hetch Hetchy Valley, but does their plan hold water?

Kolana Rock towers above Hetch Hetchy Reservoir in Yosemite National Park.

Follow the trail from Yosemite National Park's Rancheria Falls up along dusty switchbacks and down through a canopy of pines and madrones for roughly three miles, and you will reach Tiltill Valley.

Accessible only to hikers and horseback riders, the backwoods meadow hums with the chatter of birds, bees, and the distant rush of water spilling over rocks. Butterflies dart among wild orchids, lilies, yarrow, and other kinds of flowering plants that thrive there, and a lone sequoia stands along the perimeter. The valley floor is lush and boggy, with the forested hills of the High Sierra as its backdrop.

Tiltill Valley is a real-life example of what Yosemite's Hetch Hetchy Valley might look like if the reservoir that holds San Francisco's water supply were drained and the terrain allowed to return to its natural state, according to Mike Marshall, executive director of Restore Hetch Hetchy.

His nonprofit group has a singular mission, as the title suggests. The upbeat, 50-year-old former political consultant wants to place a charter amendment on the November 2012 ballot to ask San Francisco voters if Hetch Hetchy Reservoir should be drained so that the valley, which has been underwater since 1923, can be ecologically restored and turned into an attraction for park visitors.

Yet that simply stated goal belies an extraordinarily difficult and expensive task, one that would fundamentally alter San Francisco's water delivery system and diminish a city-owned source of inexpensive, green energy.

"The destruction of Hetch Hetchy Valley in the 1920s was the worst environmental disaster to ever besiege the national park system," Marshall says. "And today, it is completely out of whack with the values of the vast majority of people who live here."

But most city officials think this idea is just plain crazy. Whether or not it was a good idea to build the dam originally, they say it's unwise and unrealistic to spend scarce resources to destroy one of city's most valuable assets.

"While it is an interesting idea, I don't think that there is yet a credible plan to move forward and actually restore Hetch Hetchy that will ensure that within our budget, we'll be able to get the water that 2.5 million Bay Area customers need, as well as do everything else that the current Hetch Hetchy system does," Board President David Chiu told the Guardian.

Based in San Francisco, Restore Hetch Hetchy worked in tandem with the Environmental Defense Fund and a consulting firm to craft a technical analysis describing how the city could continue receiving reliable freshwater deliveries without the reservoir, although it would require filtration because of its lower quality and be less abundant in drought years.

While restoring the valley would be an ecological win in a perfect world, cost estimates range in the billions of dollars at a time when budgets are shrinking and economic turbulence rocks the public and private sectors.

Draining Hetch Hetchy Reservoir and replacing it with other water and power projects would punch holes in an already cash-strapped city budget, first with the high capital costs and then with higher long-term annual costs. The hydro-electric system provides carbon-free electricity to city agencies at basement rates and helps fund local renewable-energy projects, so relinquishing some of that generation capacity would be a step backward when it comes to addressing climate change.


If 3000 housholds in San Francisco turned off ONE 60watt light bulb, the Hetch Hetchy power generator would not be needed. If 20,000 housholds changed ONE 60 watt light bulb to a 40 watt light bulb, the need for Hetch Hetchy power would be erased. The power generator at Hetch Hetchy is INSIGNIFICANT.

Posted by Guest on Aug. 10, 2011 @ 10:50 am

But in any event, the decision about a great national and international scenic treasure should not be made with much regard to the view of people in any one City. It's a national/global matter - SF can be made good re water and power if necessary.

Whether SF has public or private power or water is a footnote issue compared to the massive environmental import to such an issue. And of course SF voters have never expressed much interest in municipal-owned utilities at the ballot box.

Posted by Harry on Aug. 10, 2011 @ 11:01 am

Smash San Francisco and San Franciscans! Restore the Hetch Hetchy!

Posted by Guest on Aug. 16, 2011 @ 4:48 pm

O'Shaugnessy damn can be removed, Hetch Hetchy valley restored, and San Francisco and the SFPUC customers kept whole on electricity and water.

The benefits of another Yosemite valley for the communities of the central Sierra will generate dividends far greater than any short term costs.

Given that the system is gravity fed, extra turbines can be put into place to drive the filtration systems.

Hydropower is by no means "green energy," although it is "carbon free."


Posted by marcos on Aug. 10, 2011 @ 12:02 pm

In a full analysis, Hetch Hetchy is not carbon free. When plants are drowned out by higher water levels when dam waters rise, or when new dams are built, there is a lot of biological die-off and decomposition that releases methane and carbon dioxide.

Contrarily, if the Hetch Hetchy Valley were restored, it would burst forth as forest and grassland again and return to the job of soaking up carbon dioxide in trees, vegetation, and soil.

Evaporation is also immense from dam reservoirs because they are big spaces of surface water open to the sun. That added water vapor load to the atmosphere amplifies storm events already being increased by the climate crisis; and water vapor itself is a powerful greenhouse gas.

So dams are far from carbon free and atmosphere friendly.

Posted by Eric Brooks on Aug. 10, 2011 @ 12:33 pm

on any post here.

Just sayin'.

Pull the damn dam down.

Posted by Harry on Aug. 10, 2011 @ 2:32 pm

Operationally, hydropower is effectively carbon free. The water, if left to flow naturally through the Toulumne down to the San Joaquin, would evaporate plenty in the Central Valley and Delta where flows are slack, humidity is low and temperatures high.

There is a natural water cycle of which reservoirs merely concentrate existing vapor somewhat, while in contrast, the carbon cycle had been relatively fixed until human industrial activity upped the carbon load in the atmosphere.

Set up and tear down of damns have carbon footprints that dwarf the operational footprint, although the "one-time" emission of methane generated by Hetch Hetchy 90 years ago was not a significant contributor to increased GHG concentrations when compared to the bulk of ongoing human industrial activity over the past 200 years.

The main impediment to achieving a tear down is Federal, allowing some alterations in Yosemite to tear the damn down as well as downstream in the national forest and private land to make up the water storage and electrical differences.

This project will face challenges from conservatives who believe that America's best days are behind us (you know I love saying this), that we can't afford a pot to piss in anymore. But if they continue administering their current parasitic economic prescriptions, they will have sucked the host dry enough for them to starve but hopefully not too much for us as a nation as well as Hetch Hetchy valley, to enjoy a full recovery.


Posted by marcos on Aug. 11, 2011 @ 7:25 am

The main point is that with the imminent very serious climate crisis tipping points which we now face, we need all of the restored habitat we can get in order to begin drawing carbon rapidly back down from the atmosphere into vegetation and soil.

Herrera's uneducated claims about climate are exactly the opposite of reality. We need to ramp up real renewables within our urban areas to replace -both- fossil fuels and hydro power.

With all of that said, the spiritual point is just as real.

The beautiful Hetch Hetchy valley never should have been dammed in the first place, and we need to restore it.

Posted by Eric Brooks on Aug. 11, 2011 @ 11:57 am

The more opportunities for atmospheric carbon sequestration we can re/create, the better, whether it be in Hetch Hetchy valley or by keeping as much of San Francisco's unpaved landscape sunlit and verdant.

High rise housing that satisfies its "open space" requirement through private decks and builds to full lot coverage, like damns, eliminates opportunities for carbon sequestration.

Posted by marcos on Aug. 11, 2011 @ 1:48 pm

If John Muir had his way, Hetch Hetchy Valley would not look like Tilltill Valley, it would look like Yosemite Valley. In fact, Tilltill Valley wouldn't look like Tilltill Valley; it'd look more like Little Yosemite Valley (in terms of the impact of people, it is an ugly step-child, that Tilltill, the author should get to more parts of the park). I'm not saying Muir's heart wasn't in the right place; he couldn't foresee the future though.

There is a vast wilderness up above and beyond the Hetch Hetchy, that remains so because of the lack of development brought on by the dam. Just leave it alone. What you'll get is more a-holes on horses, probably a direct trail up to the high sierra camp at Glen Aulin. Ugh, I could just imagine. A whole fleet of busses careening down that road. And worse, you'd have some dipshit gardeners trying to "recreate the wilderness", WHICH IS AN OXYMORON, and I'm sure the fencing along the paths will be low enough so that you can take pictures over the fence and not through it, but stay on the trail cause that is one expensive garden we just put in. Picture Chrissy Field, execpt that it abuts actual wilderness instead of a city.

You want the wilderness back? Leave it alone. If the dam falls down, so what? Eventually a glacier is going to come through and scrape it away for free, have some patience. But don't pretend like this is anything other than some dreamy gardening project that has nothing to do with "nature" or "the wilderness." San Francisco can drink seawater for all I care, just leave the wilderness alone. Don't insult peoples' sensibility with your utopian steady-state simulacra of nature. Nature is dynamic and messy and thrives best when unmolested. This dream of bringing back the Hetch Hetchy looks like a frankenstein to me, but hey, maybe that's because I actually spent significant amounts of time up there and not sitting in an office somewheres cooking up bs pipe-dreams.

Posted by man on the mountain on Aug. 12, 2011 @ 5:27 pm

and another thing, if you are so interested in preserving the yosemite wilderness, here's a great idea that will cost almost nothing: close down the high sierra camps and ban horses (except for rangers on duty.) those stink holes radiate human habituated animals (bears, squirrels, flies, etc.) and create an ecological dead zone around them. It may not look that way to the saddle sore novice from his considerable height above the trail, but when you spend significant time back in the true wilderness, it becomes readily apparent: the animals avoid these little villages unless they want a handout.

Posted by man on the mountain on Aug. 12, 2011 @ 5:43 pm

So you want to personally own the Sierras because you spend a lot of time there?

I grew up in the Sierras, and my stand is 180 degrees opposite yours.

If the goal is to leave nature alone and let it take care of itself, the dam needs to come down.

Dams aren't static either. The fill with silt, continuously wreck downstream habitat and biodiversity, and inhibit keystone fish species from crucial migration in large populations up and down a watershed; migration which generates absolutely vital biological activity which feeds nutrients to the entire bioregion.

Dams are wounds in Sierra ecosystems, not protective barriers.

Posted by Eric Brooks on Aug. 12, 2011 @ 5:47 pm

Eric, you must know alot, but nothing about which you are speaking in this case. I appreciate the intitial ad hominem strawman, may I offer one to you? So you want to tear down the dam just so you personally can fizzle away carbon on all these computer servers? Is that why cause, hmm?

Aside from that, all of your dam arguments are generalized, and have little or nothing to do with Hetch Hetchy.

Since you are likely both a pedant and a bore, I won't waste my time in some long-winded continuations of this explanation to keep you company, but I will a little.

First, I recommend some reading: The Battle Over Hetch Hetchy, by Robert Righter, would be a good start.

"The fill with silt" - not the hetch hetchy, (read the article you are commenting on)

"inhibit keystone fish species from crucial migration in large populations up and down a watershed; migration which generates absolutely vital biological activity which feeds nutrients to the entire bioregion." - not the hetch hetchy, that would be Don Pedro.

"Dams are wounds in Sierra ecosystems, not protective barriers." -not the case with the hetch hetchy, but then you haven't been there to know.

"That added water vapor load to the atmosphere amplifies storm events already being increased by the climate crisis; and water vapor itself is a powerful greenhouse gas." - also not relevant.

"there is a lot of biological die-off and decomposition that releases methane and carbon dioxide." - they pulled the trees, also not relevant.

"The beautiful Hetch Hetchy valley never should have been dammed in the first place, and we need to restore it." -- hey! your half right! but even John Muir's arguments at the time involved putting in hotels and other amenities, which probably would have led to looky! "bears at a dump" and a nightly "firefall" among other nonsense. That is the irony of this dam. People are too caught up in their polemics and EGO gratifications to see it clearly. If it didn't happen to be in "Yosemite" no one would be giving a fuck. Check out dams in the Emigrant Wilderness if you really care about these "wounds." You could probably take them out for 100k, and actually do some good.

By the way, I only own the wilderness "personally" when there is no one else around.

And the animals only own it when nobody is around. And the O'Shaughnessy Dam has done a lot over the years by just being there to make that happen.

Posted by man on the mountain on Aug. 12, 2011 @ 6:41 pm

I'm including Don Pedro and all dams in my analysis.

Eventually they must all be removed.

The salmon and unhindered watersheds must be allowed to return.

They are the crucial nutrient and carbon conveyor system for nearly all of our coastal bioregions.

Erosion carries nutrients down to the lower elevations and the oceans, and the salmon bring those nutrients back up.

This vital ancient relationship must be restored.

Posted by Eric Brooks on Aug. 12, 2011 @ 7:18 pm

Yes, and we must remove all the cities and people while we are at it. I thought you said you were born somewhere on this planet.

Say, you want to start removing dams of the hetch hetchy system, why not start with Cherry Lake? That is used just for hydroelectric, full of carp, and it would keep out all those yahoos with powerboats. Oh wait, that's no holy grail, nevermind.

Posted by man on the mountain on Aug. 12, 2011 @ 7:36 pm

Removing all dams is a perfectly realizable goal which doesn't in the slightest require the major shift in human civilization that you are implying.

You are now simply playing the contrarian to everything I say rather than engaging in honest dialogue.

If you are going to be a troll, go back up onto the mountain...

out of earshot and away from all internet connections... ;)

Posted by Eric Brooks on Aug. 12, 2011 @ 7:55 pm

what honest dialogue? go back and reread. you happen to be a little trollish, if you ask me.

i have addressed what you said because I think it is wrong-headed. you on the other hand have address nothing i have said, made a few ad hominem attacks and sweeping generalizations with no basis in reality. for example, the salmon aren't going anywhere near the hetch hetchy (if they ever would) without the removal of the don pedro. so why don't you start there and stop barking up the wrong tree? also read that book i recommended and get back in a few days. you are just ignorant on this subject, nothing to be ashamed of.

i do prefer mountain trolls, they are sensible creatures compared to the ones you find around here.

Posted by man on the mountain on Aug. 12, 2011 @ 8:08 pm

Apparently, you are so hot to get in a shouting match that you are not reading everything I wrote in this thread before typing.

I countered one of the many absurd claims you made quite specifically and gave the link to a web site to show the proof. (Sorry I'm not going to take every single one of them on; I don't have that kind of time.) I also specifically clarified that indeed, Don Pedro needs to come down in order for anadromous fish to return to that watershed.

To be blunt, I don't take seriously the pseudo-scientific arguments of a person who is uneducated enough to believe that Hetchy doesn't collect silt.

That pretty much disqualified you right off the bat in the take-what-I-am-saying-on-faith department. And it shows that your puffed up posturing, that I somehow don't know what I am talking about is highly questionable.

I grew up in those mountains. I am an environmentalist of many decades experience, part of which was specifically dedicated to watershed restoration.

I do indeed know what I'm talking about.

Posted by Eric Brooks on Aug. 12, 2011 @ 8:30 pm

fair enough, you posted a link. my comment happend you cross paths with it on the internets. as i began writing my comment, however, that was not the case.

your link was an anecdotal comment of someone who took a boat up to the front of the lake during the spring drawdown and saw some stumps and silt. i can even begin to tell you how scientifically irrelevant that is. you should know better if that is your specialty. of course the hetch hetchy collects silt. in fact alot of that silt your eye-witness saw was probably there even before the dam, seeing how it had stumps in it.

whwen you talk generally about dams and their effects on the enviroment, do you suppose there might be some individual variations, say, i dunno, glen canyon dam vs. o'shaughnessy? what's coming down stream from where? to suppose that the hetch hetchy doesn't collect silt to any degree significant to make it a part of the argument is hardly pseudoscience, and speak to the lengths someone like yourself goes to find proof for something they are already convinced of.

what would interest me, is what you would think of the wilderness up above the hetch hetchy, because apparently, protecting the wilderness is what this crusade is all about.

Posted by man on the mountain on Aug. 12, 2011 @ 8:45 pm

Let's look at this from another perspective.

Rivers and streams can be analogized to the circulatory system of the human body. They serve pretty much exactly the same purposes to the land, as our blood vessels do to our bodies.

Imagine for a moment, what would happen to your health, if miniature space aliens came along one day and colonized the inside of your body.

Further imagine, that they decided for various reasons (ease of agriculture, industry, etc) to start putting dams all over the place in your circulatory system, artificially pooling your blood in various reservoirs, using the collected blood for agriculture, industry and recreation instead of letting it flow freely to your organs, your extremities, your digestive system, and most importantly, your heart and brain.

Imagine what this would do to your body.

That, is what we have done to the land, and the mountains, every watershed, and even the sea.

Posted by Eric Brooks on Aug. 12, 2011 @ 9:17 pm

Oh brother! I was hoping to read a decent rebuttal to MOTM's comments, but all Eric Brooks did was prove MOTM's points with this last nonsensical diatribe. Surely that's why this particular conversation ended here.

Thank you, Man on the Mountain, for giving me some genuinely useful information and insight into this highly emotionally charged issue. Thank you very much.

Posted by Guest on Aug. 22, 2011 @ 10:24 am

By the way, don't mistake Tyrone Jue's crystal clear water salespitch as a claim that Hetch Hetchy doesn't collect silt.

All dam reservoirs do. It is impossible for them not to.

In fact David Brower describes Hetch Hetchy silt deposits in an essay at:

Posted by Eric Brooks on Aug. 12, 2011 @ 7:46 pm

have you even seen the hetch hetchy? i am curious.

you should see the streams and river that flow into it. those things are sparklingly clear. I'm sure there is some silt. Hell, the valley was basically comprised of grass growing on silt. I don't know if they tested the silt since that 1990 highly biased "article" but i imagine, given what is happeneing up there, the greatest source of silt would be the retreat of the high country snow fields or the occaisonal massive flood. probably though, a lot of that silt would have been deposited in the valley whether or not there was a dam, that's how those meadows are created out of lakes over time, until the glacier comes by and scrapes it clean.

don't worry eric, you'll get what you want, you don't even have to lift a finger. it's just not going to happen in your lifetime or anytime soon. the mountains operate on geologic time.

Posted by man on the mountain on Aug. 12, 2011 @ 8:22 pm

If you take out this water supply are you doing to replace it, are you going to move on to Don Pedro there is more to the bay area beside San Francsico. What are you doing to do with the other water users, power users.

Posted by Garrett on Aug. 16, 2011 @ 6:27 pm

Conserve and recycle and -lot- more water, and switch to true renewables like wind, solar, efficiency; and electric mass transit.

Posted by Eric Brooks on Aug. 18, 2011 @ 8:57 am