A soon-to-be-released report from the US Geological Survey finds the Sacramento-San Joaquin delta would be hit even harder by an earthquake than previously believed, but with winter rains, the Delta would also recover more quickly than was estimated in a state study just three years ago.
This excellent story by Pat McBroom in The California Spigot highlights the earthquake risk, but given that previous scenarios predicted it could take as long as eighteen months for the Delta and State Water Project to recover from a 7.0 earthquake on the Hayward fault, a projected three-to-four month recovery, with winter rains, might even count as good news.
“It’s not true that a
major earthquake would mean the end of the delta and we’d never be able
to use it again,” said Greg Gartrell, a hydrologist with the Contra
Costa County Water District, who is familiar with the new modeling. “Yes, you get a lot of salt water coming in, but as soon as it rains,
that water can get washed out.”
Pumps that supply California’s urban
and agricultural water would have to stop for about three to four
months, under the conditions studied, said Gartrell, and then could
become operational again. Most urban water districts have local water
supplies to cover such a period.
Politically, this means that the underlying justification for the so-called "isolated conveyance" — a euphemism for the politically untouchable peripheral canal, defeated in a l982 vote — is taken away.
Will the water bond that was taken off the ballot this fall ever come back?
Here's the delta, and, by the way, here's another excellent (if less cheering) story about it from the Contra Costa Times, called Delta: A Lake in the Making.