Water, Water Everywhere
Record rains and leaky levees have Northern California bracing for a Katrina-like disaster
TRACY, CALIF.--In California, they call their push to shore up levees during the wet season a "flood fight," but today it's looking more like a war. In San Joaquin County, where the river is within just inches of flood level, almost 500 government workers last week combed the earthen levees for signs of trouble. "They're finding dirty sand boils," said county spokeswoman Elena Reyes, referring to pockmarks that indicate water seepage. Nearby, prisoner work teams wrapped vulnerable embankments with thick plastic sheeting.
It's an all-out effort--and for good reason. California is enduring its fifth-wettest season on record, and it looks like a world gone haywire. Cold rains have pummeled the northern part of the state almost continuously since early March; in some sections of the Sierra Nevada range, the snowpack is nearly twice its normal size and will melt into already swollen rivers--the only question is how fast.
The focus now is on the southern tip of a sinuous 1,600-mile levee system in the Sacramento-San Joaquin Delta, a key soft spot in the 6,000 miles of levees that snake through the center of the northern half of the state. So far, it looks as if the delta will survive this battering, but Hurricane Katrina--and the latest bout of storms--have riveted attention on a levee system many say is doomed to eventual failure. Its crumbling would be a body blow for the entire state.
The delta is a water-management nightmare. Roughly 740,000 acres, the area used to be a giant tidal marsh--California's version of the Everglades--before farmers began channeling water behind levees about 100 years ago to create pockets of fertile land. These "islands" are protected by levees managed largely by small, private reclamation districts, sometimes just a handful of neighbors who maintain the levees themselves. What's worse, "every day the delta takes a breath," says Jeffrey Mount, the director of the Center for Watershed Sciences at the University of California-Davis, "and exhales bits of its own soil into the atmosphere." Gradual land erosion has put most of the farmland below sea level, which creates enormous pressure on levee walls. A recent study by Mount found a greater than 60 percent chance that the levees will experience a catastrophic failure, submerging several islands, sometime in the next 50 years.
The consequences of such failure would be greater than just drowning some sparsely populated farmland. The water supply for roughly two thirds of Californians depends on the delta. A failure of the levee system could contaminate the supply by pulling in salt water from the San Francisco Bay. State officials estimate it could take 18 months for them to even begin restoring a supply of fresh water, and that might not, in the end, be possible at all. Adding to the pressure is the fact that the population of the delta is growing. It's home to more than 500,000 people today, but at least 115,000 new homes are planned here in the coming years.
"Be extremely worried." Just above the delta's northern rim, the city of Sacramento, at the confluence of the American and Sacramento rivers, is considered to be in much better shape. But even its vulnerabilities are staggering. "When Sacramentans hear there is a 1-in-4 chance they'll have a flood during their 30-year mortgage," says retired Brig. Gen. Gerald Galloway, formerly with the Army Corps of Engineers, "they should be extremely worried." California's capital city has less protection than any other major urban area in the nation: At best, its levees can protect against the so-called 100-year storm, the kind of event that scientists expect to occur once every century. Before Katrina, New Orleans's protection was in the 250-year range.
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