I know you’ve all checked out our nifty map showing where the next likely "Unnatural Disaster" will take place. In the same vein, check out this L.A. Times editorial on a possible Cali earthquake and its consequences for the levees that hold the state’s elaborate water infrastructure together. Grim.
Should a magnitude 6.5 earthquake strike the San Francisco Bay Area — almost a certainty by mid-century, though it could happen today — about 30 major failures can be expected in the earthen levees.
About 3,000 homes and 85,000 acres of cropland would be submerged. Saltwater from San Francisco Bay would invade the system, forcing engineers to shut down the pumps that ship water to Central and Southern California while the levees were being repaired. This would cut off water to the State Water Project and the federal Central Valley Project.
The [Metropolitan Water District] has a water reserve of six months set aside for such a crisis, and it also accesses water from the Colorado River. Multiple smaller water agencies south of the delta, however, have no such reserves or alternate sources of supply.
Think of it: 3,000 homes under water; 16 delta islands and 85,000 acres of cropland lost to flood; drought conditions in Central California, followed by drought conditions in Southern California as thirsty people drink up MWD reserves in the first six months of a 12- to 18-month reconstruction period. Nor would the MWD be able to tap into an increased supply of Colorado River water, these resources having long since been allocated to Nevada and Arizona.