A major winter storm at a 500 year level—comparable to those of the 19th century—hit the West Coast.
Sacramento would be in deep water!
We believe dams are the solution, raising Shasta to its originally engineered height, posted on here, and building the Auburn Dam, giving us the 500 year protection necessary to protect us from such storms, posted about here and here.
The US Geological Survey studied the what if, and has published a report, which today’s Sacramento Bee reported on, and the last two paragraphs of the excerpt (highlighting added) are the bottom line.
“California has more risk of catastrophic storms than any other region in the country – even the Southern hurricane states, according to a new study released Thursday.
“The two-year study by the U.S. Geological Survey is the most thorough effort yet to assess the potential effects of a "worst-case" storm in California.
“It builds on a new understanding of so-called atmospheric rivers, a focusing of high-powered winds that drag a fire hose of tropical moisture across the Pacific Ocean, pointed directly at California for days on end. The state got a relatively tame taste of the phenomenon in December.
“The team of experts that developed the scenario can't say when it will happen. But they do say it has happened in the past and is virtually certain to strike again.
"This storm, with essentially the same probability as a major earthquake, is potentially four to five times more damaging," said Lucy Jones, USGS chief scientist on the study. "That's not something that is in the public consciousness."
“The study aims to fix that.
“A conference on the subject, ending today at California State University, Sacramento, brings together hundreds of emergency planners to discuss the worst-case storm and how to prepare for it.
“The USGS is assessing a variety of natural hazards across the country. California was chosen for the latest project, called ArkStorm, because the state "has the potential for the biggest rainfall events in the country," Jones said.
“In December, an atmospheric river threw a series of wet storms at the state, breaking rainfall records in many areas across California. One part of Los Angeles County got 17 inches of rain in three days. Disasters were declared in 11 counties.
“In the study, researchers used computer models and a composite of three historical storms to estimate a worst-case event: a torrent of tropical rain for nine straight days.
“It amounts to a 500-year storm. In the lingo of disaster managers, that does not mean it happens only once every 500 years, but that it has two-tenths percent chance of occurring in any given year.
“The Central Valley and the Sacramento region are likely to suffer the worst effects because they lie within a funnel for the state's biggest rivers.”