SPENCER MICHELS: This giant dam in the Hetch Hetchy Valley of California's Yosemite National Park is the focal point of a battle between the city of San Francisco, which built the dam nearly a century ago, and environmentalists who want it torn down. It's the latest and probably the most contentious example of a growing movement to eliminate dams in scenic areas around the nation. Ron Good founded Restore Hetch Hetchy.
RON GOOD: For many years, this has been a kind of private enclave for the city of San Francisco. They get millions of dollars a year from the sale of water and power. But this is a place in Yosemite National Park that belongs to all the American people and it really should be returned to all the American people.
SPENCER MICHELS: A few miles south of Hetch Hetchy, in California's Sierra Nevada Mountains, lies Yosemite Valley, with its majestic mountains of granite and its spectacular waterfalls. Just four hours east of San Francisco, the valley draws three million visitors a year; it is often crowded with people from all over the world. But the Hetch Hetchy Valley -- also within park boundaries -- has been seen by very few people in the last 100 years.
Depicted here in a century old photo and in this celebrated 1880 painting by Albert Bierstadt, the Hetch Hetchy Valley is almost ethereal, with trees and an ambling river walled in by towering mountains of stone. But it hasn't looked like this since 1915.
That was when preparations began on the massive dam to trap and use the waters of the Tuloumne River by creating a giant reservoir that would flood the valley and send pure mountain water through pipes and tunnels 167 miles across California to San Francisco and 33 nearby communities.
The construction was considered an engineering marvel, carried out by thousands of workers, led by San Francisco's chief engineer Michael O'Shaughnessy, for whom the dam was named. O'Shaughnessy and his backers were part of the nation's progressive elite, according to California historian Kevin Starr.
KEVIN STARR: The Hetch Hetchy comes out of a larger movement in America, in which this country in the early 20th Century laid down the infrastructure of modern America. The progressives, while not overtly religious, had a sense that public works represented the highest ethical governmental activity possible on the part of concerned citizens. To lay down the public works infrastructure for what they envisioned as a great civilization that would rise up here on the shores of San Francisco Bay.
SPENCER MICHELS: But not everyone agreed. John Muir, considered the father of this country's national parks and the environmental movement, hated the idea of destroying a gorgeous valley. "No holier temple has ever been consecrated by the heart of man," he wrote.
For decades, Muir led a spirited battle against the dam, along with the Sierra Club, which he founded. But following the 1906 earthquake, low water pressure was blamed for the fire that wiped out San Francisco, helping convince easterners that the city needed a more reliable water system. In 1913, Congress approved the Hetch Hetchy project. Muir died the next year. The system began delivering water in 1934, and the dam created a lake containing 117 billion gallons of water when full. Superintendent Norm Rickson has worked here for more than three decades.
NORM RICKSON: There's not a pump on the system anywhere. It's totally gravity fed. It's not filtered. It's a pristine water system. It's a wonderful, wonderful system. Environmentally speaking, I mean, I don't know how you can do any better than this.
SPENCER MICHELS: Still, limited public access to Hetch Hetchy Valley, and no access to the reservoir because it might pollute the water, has bothered some people, including the Sacramento Bee's Tom Philps, who won a Pulitzer Prize this year for a series of editorials advocating the dam's removal.
TOM PHILPS: We weren't afraid to suggest something that some people would consider as heresy. What made sense for this valley in 1913 might actually not make sense in a state with 50 million people in it with other ways to store this same water, and we're running out of Yosemite Valleys. We have two of them. We've basically gotten away for the last century enjoying just one of them.
SPENCER MICHELS: At first, the concept of destroying the dam and the reservoir was regarded as an environmentalist's pipe dream. But as more and more dams were eliminated across this country -- 175 in the past six years -- San Francisco water officials began to take it seriously, and now they're fighting back. They were eager to show us how, they say, the reservoir actually enhanced the beauty of the valley, taking us out on the only boat allowed on the lake behind O'Shaughnessy Dam. Beneath these waters lie the stumps of trees that grew in Hetch Hetchy Valley. Still visible above the surface, Wapama Falls crashes dramatically down from huge granite cliffs, accessible only by hikers willing to walk around the lake. Superintendent Rickson says restoration of the valley would be difficult.
NORM RICKSON: You know, it would be like a mud puddle for a while. You'd have a white ring around the rocks where the pure water leaches mineral out of the rock. I don't know what the plans would be to restore it back to its natural state would be - you know, it would take hundreds and hundreds and hundreds of years to do so.
SPENCER MICHELS: Really?
NORM RICKSON: I mean, you know, just to grow the trees back. Trees don't grow in 40, 50 years.
SPENCER MICHELS: The San Francisco Public Utilities Commission runs Hetch Hetchy. And its general manager, Susan Leal, says she was shocked by proposals to "dismantle an elegant water system," as she puts it.
SUSAN LEAL: It's not like Legos where you can just take out one piece and you can just replace it. You're removing the gravity part of it, you're removing the clean hydropower, and as you know, we've had energy crisis in this state.
SPENCER MICHELS: San Francisco gets 20 percent of its power from Hetch Hetchy, enough to run streetcars and buses and other municipal projects, and sells power at cost to nearby irrigation districts. But it's the disruption of water supplies that most bothers the city.
SUSAN LEAL: You know, we're in a semi-arid state. This is California's gold. And for us to eliminate a source, probably one of the best sources of water, not only in the state but in the world, is foolhardy.
SPENCER MICHELS: But the water storage and the water could be replaced, concludes a report commissioned by Environmental Defense. Using newly developed computer modeling techniques, University of California scientists investigated what the loss of O'Shaughnessy Dam would do. Graduate student Sarah Null and Professor Jay Lund did the work.
SARAH NULL: Surprisingly, very surprisingly I think to both of us, it said that we could take out O'Shaughnessy Dam with very little changes to the system, very little water scarcity or water shortage.
JAY LUND: It's a little bit like packing your garage a little bit more efficiently so you can get a second car in.
SPENCER MICHELS: Meaning?
JAY LUND: Meaning if you improve the operations of the storage that you have, maybe you don't need that extra garage.
SPENCER MICHELS: One solution frequently mentioned is to enlarge the storage capacity of downstream reservoirs like Don Pedro, perhaps by raising its earthen dam. Costs for reconfiguring a new system are estimated at between $1 billion and $10 billion. Editorial writer Philps says it's a good tradeoff.
TOM PHILPS: This kind of money is considerable, but what is this place worth as a second Yosemite Valley? What is that worth in economic terms? It's got to be in the billions as well.
SPENCER MICHELS: Still, convincing city, state and federal officials, plus the public, to dismantle Hetch Hetchy is a formidable task.
KEVIN STARR: For multigenerational San Franciscans, such as myself, the Hetch Hetchy is part of the DNA code of San Francisco. It is one of the foundations upon which the greatness of this city rests -- that to comprehend disestablishing it, tearing it down, going somewhere else, is almost to think the unthinkable.
SPENCER MICHELS: Nevertheless, Gov. Arnold Schwarzenegger has ordered the state to take a serious look at the concept. A report is due out in the fall, but it certainly won't be the last word on whether to reverse a policy and a water system forged in heated public debate a century ago.