Nature Noir by Jordan Smith (romantic books to read .TXT) 📗

troupe's piano by lifting it onto a pile of debris, but the water soon rose to the height of the bar and they swam to safety. Nearby, the owner of the historic Shanghai Bar and Restaurant tried to keep the creek out of his business by barricading the back door. The water soon found its way through the kitchen window, and he fled to higher ground.

The damage in Auburn was limited to the plaza along the bottom of Auburn Ravine, but where the American River flowed into the flat Central Valley, the situation was far more serious. One residential neighborhood near Sacramento State University is fifteen feet below the waterline of a major flood. In the Natomas Basin on the city's northern edges, the figure is twenty. In 1986, only two things stood between Sacramento and that water: a system of levees begun after the flood of 1850 and improved ever since—usually after they failed—and a single dam, Folsom, about twenty miles east of the city.

If much of the energy behind the construction of Folsom Dam had been generated by fear of flooding, by 1986 the dam was operated by the Bureau of Reclamation, an agency chartered to provide irrigation water, not flood control. At that time, of the reservoir's million-acre-foot capacity, only 400,000 acre-feet of space were normally kept available for flood control. But so far that winter had not been a wet one, and the Bureau had begun hoarding water to fulfill its irrigation contracts with farmers. Thus when the storm began, only three quarters of the usual flood storage capacity was available, or 300,000 acre-feet. Further, although the Bureau had its own weather forecasters, the agency based its decisions on how much water to release from the dam on changes in the lake level, not on their predictions. Thus the Bureau's responses were delayed—even to rain that had already fallen in the mountains but hadn't yet reached the lake.

Monday night the inflow to Folsom hit 200,000 cubic feet per second (CFS), but the Bureau could release only 115,000 CFS from the dam, which was the known capacity of the levees downstream, through Sacramento. And so Folsom Lake rose steadily toward the dam crest.

The deathwatch at the Auburn cofferdam began after midnight Tuesday, February 17. In the predawn hours, engineers from the Bureau set up a video camera along the canyon wall above the dam, intending to learn what they could from its destruction. By five-thirty that morning the sheet of brown water filling the canyon had reached the dam's crest. At dawn the engineers turned on the camera and stood there glumly in the drizzle to witness what would happen. The wind and rain in the canyon bottom had let up, and, looking upstream, the engineers could see a little stream of water trickling over the left side of the dam, reflecting the pale morning sky. The little creek over the dam crest looked peaceful. But the dam was made of earth, and bit by bit the creek excavated a deeper channel for itself, and as it did, its volume increased and the erosion quickened.

It took about three hours for the dam to wash out. In Skyridge, a subdivision of what had been intended to be lake-view homes on the Auburn side of the canyon, people were taking the day off from work to stand on their decks and watch their tax dollars go down the river. Six-packs and bottles of wine showed up. A partylike mood prevailed. After all, this wasn't something you saw every day—a dam failing, one man told a visiting reporter. Beneath them the little creek running down the dam face had become a horseshoe-shaped waterfall that grew steadily, 25, 50, 70, then 100 feet high as portions of the dam collapsed into it. At the bottom the rusty brown water exploded upward in a hellish maelstrom, filling the canyon with an unearthly rumble. There was something strangely beautiful about it—but not for the Bureau engineers. When the erosion finally reached upstream to the lake the dam was holding back, the whole left side of the structure melted in a heroic climax of water and mud, and a hundred thousand acre-feet of stored water roared downstream into Folsom Lake. It was a hundred thousand acre-feet the Bureau hadn't made space for.

William Hammond Hall, one of the great nineteenth-century civil engineers who studied floods in the Central Valley, said there were two kinds of levees: those that had already failed and those that would. Now Sacramento's would be put to the test. When the contents of the cofferdam spilled into Folsom, the Bureau had no choice but to raise releases from Folsom to 130,000 CFS—two and a half times the displacement of an Enterprise-class aircraft carrier every minute, and 15,000 CFS more than the levees were designed to take. Inside the dam a couple of the operators followed a cata-comb-like passageway to a door opening onto a steel inspection walkway a couple of hundred feet up the dam's downstream face. Outside, they had to hold on to the railing to keep from being blown off by gusts from the massive pile of whitewater beneath them. The noise and drenching spray were beyond description, one of them told me later, and the whole 340-foot-high dam seemed to vibrate under their feet.

Down the river in Sacramento, five hundred levee-tenders were now deployed twenty-four hours a day to watch for breaks in the tenuous mounds of earth that kept the swollen rivers at bay. On the Sacramento River just upstream of the mouth of the American, they opened a row of escape weirs through the levee, allowing some of the Sacramento's flow to make its way around the city in a sacrificial channel of farmland known as the Yolo Bypass. So much water was coming down the American that now the Sacramento River began flowing backward, from the mouth of the American to the bypass weirs upstream.

Other crews went around reinforcing weak spots as they