San Francisco’s water has a sour history that belies its sweet taste. The city’s drinking water — and its hydropower — come courtesy of the Hetch Hetchy Reservoir in the High Sierra. The reservoir traps and slackens the once-pristine Tuolumne River, which lies within the protective boundaries of Yosemite National Park. That legal detail did not stop politicians and developers in the 1910s from building the 312-foot-high, 900-foot-long O’Shaughnessy Dam, drowning a one-of-a-kind towering granite gorge of waterfalls and wildflowers.

In Dam! author John Warfield Simpson, professor of landscape architecture at Ohio State University, has written a thorough history of a controversial project. He shows that today’s struggle between conservation and economy has roots that extend back into the 19th century, when the two major philosophies regarding public lands emerged. Representing preservation were men like John Muir, one of the few Americans who actually camped along that famous stretch of the pre-dammed Tuolumne River. On the other side were utilitarians such as Gifford Pinchot, who saw public lands as Congress eventually would: as existing "for the purpose of securing favorable conditions of water flows, and to furnish a continuous supply of timber."

Simpson reports that Hetch Hetchy has lately become a new poster child for the drowsy environmental movement. Many national groups, including the Sierra Club and Restore Hetch Hetchy, would like to see the O’Shaughnessy Dam removed by 2013, the 100-year anniversary of the Raker Act, which stripped away national park protection for the area. Studies indicate that water sources could be found elsewhere, and might even be cheaper and more dependable than the ancient and leaky 167-mile-long aqueduct delivery system now in place.

"Let us now remove that dam," Simpson concludes, "and ... voluntarily limit our economic-based exploitation of nature for a high concept of the greater good."