[...] a 6.5-magnitude earthquake could collapse 30 levees, flood 16 delta islands and damage 200 miles of additional levees. [This] would allow salt water to rush in to the river system, causing an immediate shutdown of the pumps[;] cities would have to use alternative water sources and resort to rationing. Three state highways and railroad tracks would be submerged, and petroleum and natural gas pipelines would shut down. "This is not a worst-case scenario," [the California Department of Water Resources] said.
Strengthening levees around just three islands at the mouth of the delta could reduce 70 percent of the risk.
Lawmakers said there is not enough money for levee improvements.