UC Davis geologist Jeffrey Mount has sounded the alarm for years about California's crumbling levees. Despite wakeup calls like Hurricane Katrina, Mount says the state's levee system is as vulnerable as ever.
"I think from a Katrina style disaster, right behind me is Sacramento and that remains the No.1 worry for flood control in California," he said.
In 2006, Gov. Arnold Schwarzenegger declared a levee emergency and vowed to pump $500 million into upgrading the state's 150-year-old levee system.
Since then, about 100 of the most critical sites have been improved, but many more remain untouched.
"The Folsom Dam is being upgraded, but the levee work really lags. We authorized, you and I and other voters authorized bonds to be sold, but those folks over there at the Capitol, they can't get their act together to raise enough money to pay for the bonds," Rep. John Garamendi, D-Walnut Creek, said.
Garamendi says it's not just state officials who have failed California, but also federal.
"One of the problems here is where is the Corps of Engineers? Where are they? You don't touch these waterways without the Corps and they're simply absent, they're in Afghanistan," he said.
A catastrophic levee failure could take many forms.
"The worst case scenario is a major earthquake, in the Delta during the summer because what happens there is you bring salt water in from San Francisco Bay to fill the subsided islands. You shut off the state water project and you shut off the Central Valley Project," Mount said.
The fresh water supply for 25 million Californians would be cut off indefinitely. Neighborhoods like Sacramento's Natomas could be under as much as 22 feet of water and in West Sacramento some homes could flood up to the second story.
Barbara ingle has lived in a West Sacramento subdivision for 10 years in the shadow of a huge levee.
"I feel secure they're repairing the levees, I feel secure that this is a brim, and I feel that we have a watchful eye on it," he said.
Experts say it is an expensive problem to have. For instance, it would cost about $20 billion to restore the levees to the condition they were in 50 years ago.