How extreme weather could threaten California’s dams

How extreme weather could threaten Californias dams | ltc-a

You may have heard that climate change in California is exacerbating what is sometimes called « weather whiplash »: Dry spells are getting longer, interrupted by storms that get bigger and more furious.

In other words, our extremes are getting more extreme.

For a recent issue of The New York Times Magazine, Christopher Cox addressed the question of how extreme weather could threaten California’s dams, an essential part of the state’s complicated water storage and distribution system.

California is home to the tallest dam in America, located 60 miles north of Sacramento in Oroville. A failure of that dam would be catastrophic; in a particularly alarming scenario, it would send a wave more than 185 feet high into the valley below, inundating several towns. When the St. Francis Dam in northern Los Angeles County failed in 1928, the disaster was one of the deadliest in state history.

But in a state threatened so regularly by Mother Nature, the risk of flooding from a dam failure tends not to attract much attention. And this despite the fact that just six years ago, as Christopher reported, the Oroville Dam almost failed.

“Fires happen more frequently, and drought years are more common than wet ones,” he told me. « But the biggest disasters in the history of the state have been the floods. »

California’s dams are not prepared for extreme weather, experts told Christopher.

In 1862, the worst flood in the state’s recorded history drowned the Central Valley and, according to one account, destroyed a quarter of all buildings in the state. But most of the flood data used to design our dams comes from the last century, which experts say was an unusually calm time for California’s climate.

Now, though, the storms are getting more furious as the atmosphere warms and the amount of water vapor it can carry increases. « All of this infrastructure, » said Daniel Swain, a climate scientist at UCLA, « is designed for a climate that no longer exists. »

Some scientists have urged the state to prepare for a storm the size of that of 1862, but there has been little progress. Dale Cox, a former project manager at the United States Geological Survey, told Christopher he thought part of the reason was that floods don’t captivate the public in the same way earthquakes do, which are more sudden and dramatic.

« While an earthquake is more like an act of God, » Cox told him, « floods point out the shortcomings of man. »

A truly comprehensive approach to dam safety tends to elude them, as meteorologists, hydrologists, engineers and climatologists focus only on their pieces of the equation and not the big picture. This seems to make officials and experts particularly tight-lipped about the issue.

« Dam safety, » wrote Christopher, « is an orphan problem. »

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Today’s tip comes from Phoenix Kanada, who recommend visiting the Manzanar National Historic Siteone of 10 camps where the US government incarcerated Japanese Americans in the 1940s:

“It really is a balance of beauty and darkness as it commemorates the thousands of Japanese Americans who were sent here during WWII. The site serves as an important reminder of this country’s past and how we as a people can be more understanding of one another. Also, the landscapes in the Owens Valley (where this site is located) are truly remarkable.”

Tell us about your favorite places to visit in California. Email your suggestions to We will share more in future editions of the newsletter.