When the Levee Breaks

Even before the torrential New Year's rains hit Northern California, causing widespread flooding in several counties, worried minds -- made all the more so by scenes of a drowned New Orleans -- had turned their thoughts to the vulnerability of the Golden State's primitive levee system.

Unbeknownst even to many Californians, the state has thousands of miles of levees that are meant to protect the Central Valley and the lowlands of the Sacramento River Delta from flooding. A major collapse of those levees, caused either by flooding or earthquakes, would mean catastrophe for much of the state. The Delta, via considerable plumbing (namely, canals), irrigates some of the world's most productive farm land and supplies freshwater to more than 20 million residents of urban Southern California and the San Francisco Bay Area.

As environmental journalist Marc Reisner wrote in his last book, A Dangerous Place, about the perils of life in California,

With levee protection lost, the below-sea-level Delta would become in effect, a vacuum, which nature abhors. Water would pour in there as it would down a manhole. A lot of it would be salt water sucked in from the bay. ... Within hours or days, all that water would be unusable and undrinkable ...

So, what is being done to guard against such a scenario? As the NewsHour's Spencer Michaels reported on PBS:

The legislature will take up flood protection in early 2006. California is considering a bond issue to strengthen its levees, and is asking the federal government for help. Meanwhile, perhaps 200,000 homes are slated to be built in the delta and near unpredictable rivers in the next few years.

Ah yes, the floodplain: Prime real estate.