anyone familiar with the drowning of New Orleans by Hurricane Katrina will tell you this: Levees fail.There's much more; read it.
In Texas City, Tex., for instance, levees protect 50,000 residents and $6 billion worth of property, including almost 5 percent of the nation’s oil-refining capacity. Imagine the consequences, in this day of $100-a-barrel oil, if those defenses fail.
Even more vulnerable are the 1,100 miles of levees in the Sacramento-San Joaquin River Delta, north of San Francisco. Cobbled together 150 years ago to provide farmland, they are now part of an intricate, fragile system that supplies fresh water to California, the eighth-largest economy in the world.
Should the levee crack, be overtopped by a storm or liquefied by an earthquake, saltwater will surge inland, destroying lives, perhaps flooding Sacramento and paralyzing California.
I'm no expert on this matter but it seems plausible enough to me based on what we have seen lately. It seems like yet another problem with the same "don't bother me 'til it's too late" flavor that we're seeing everywhere; yet another place where competent government has taken a back seat to political expediency and knee jerk tax aversion.
Here's the mentioned list of 122 known at-risk levees according to the Army Corps ca. 1 year ago. The Texas gulf coast levees don't make the list, but they seem pretty vulnerable to coastal settling and sea level rise. There's also nothing here about New Orleans, so make of it what you will. It seems from the accompanying press release that this might not be intended as an exhaustive list.