State's Levees Vulnerable in Quake
A major earthquake in the Sacramento-San Joaquin Delta could cause widespread levee failure and flooding, costing the state more than $30 billion in long-term losses and tens of thousands of jobs, a state official warned Tuesday.
In testimony before a joint legislative committee in Sacramento, Lester Snow, director of the Department of Water Resources, said a magnitude 6.5 earthquake in the western delta could tear 30 breaches in the levees that protect water supplies for 22 million Californians and some of the nation's most productive farmland.
The resulting delta flooding would shut down water shipments to Southern California cities and San Joaquin Valley croplands, rupture natural gas and oil pipelines and topple electrical transmission towers.
David Mraz, the delta levees program manager who prepared the earthquake scenario presented by Snow, said it could take five years and billions of dollars of work to restore full water deliveries from the delta. In the meantime, vegetable production in the San Joaquin Valley would dry up, cities would be forced to adopt stringent water conservation measures and some farm communities would permanently wither.
"I think there would be portions of the economy that would not fully recover," Mraz predicted. "I think we would be a changed society in some senses."
He added that job losses, primarily in agriculture, could exceed 30,000 and the cost to the state's economy could total $30 billion to $40 billion, much of it in lost crop production in the first five years after the earthquake.
Mraz said farmers would turn to groundwater to sustain their more valuable crops, such as fruits and nuts, straining already depleted groundwater supplies.
Snow's testimony was the latest warning about the perilous state of the levee system that protects the delta, a maze of reclaimed agricultural islands and waterways that provide nearly two out of three Californians some portion of their water.
Snow said that in an earthquake many of the earthen levees are expected to fail, flooding 3,000 homes, 16 delta islands and letting saltwater from San Francisco Bay rush toward the big pumps that send water south through the State Water Project and the federal Central Valley Project. The pumps would have to be shut down during repairs to key levees to block the saltwater.
