Extraordinary Winter Tests California Flood Control
OROVILLE (CBS SF) -- On one hand, it was a textbook lesson in the power of small problems, or in this case, a small breach in a dam spillway that almost caused a catastrophe.
On the other hand, the crisis at the Oroville Dam can teach a larger lesson about the state of California's water infrastructure, an aging system that has to work perfectly, while the smallest cracks and mistakes can lead to catastrophe.
The first problem is that a lot of California's infrastructure is old. Hetch Hetchy, which stores water for the city of San Francisco, was flooded in the 1920s. Shasta Dam was built in the 1930s. Oroville Dam is relatively young, completed and opened by Governor Ronald Reagan in 1968.
"To some degree, we have a problem with the previous generation's success," says Jay Lund, a professor of civil & environmental engineering at U.C. Davis. "They did such a good job that we haven't had to put our best people, and as much of our best money into that as the previous generation when it was first built."
"We built a lot of infrastructure in the 20th century," explains Dr. Peter Gleick, who studies California water for the Pacific Institute. "That infrastructure was built assuming the climate wasn't going to change, and that assumption, we now know, is no longer true."
Not even a year ago, California was looking at Lake Oroville and complaining that El Nino hadn't delivered enough water. In 2017, the goal was understandably conservation. "Because you've just had a drought, you're trying to capture all that water, you don't want to lose it," says Lund. Now, that same dam is expected to turn on a dime and move record amounts of rainfall, and Oroville, like most damns, wasn't really built for that kind of agility.
"I think part of the challenge in the 21st Century," explains Dr. Gleick, "redesigning our flood system to accept more flood risk and reduce the population's exposure to extreme events."
And engineers have a pretty good idea of how to do that, in fact, they're doing it right now at Folsom Dam where work is almost finished on a second spillway. Because the new gates sit 50 feet below the original spillway gates, the lake level can be brought lower, sooner, meaning dam managers can make room for big storms well before the water starts climbing toward the top of the dam. That project, however, was extremely difficult and expensive. It took ten years and almost a billion dollars to improve Folsom Dam, and it might not have happened without another American flood disaster.
"Katrina did more good for California flood control than any other storm did in a long time," says professor Lund. Katrina prompted an extensive repair of the levees protecting Sacramento - but the risk didn't end there.
"We have levee risks, we have flood risks. The delta is a problem," says Dr. Gleick, who says most of California's water problems do eventually run through the Sacramento-San Joaquin Delta. Here a flood or an earthquake could leave two thirds of the state without water.
Now if fixing all of this sounds unimaginable, just think about what almost happened up at Oroville.
"You don't want too much failure," says Lund, "but a little failure makes you go back and look at things."
The more California steps back and look at things, the more apparent it becomes that the state may be do for a full scale re-evaluation of it's flood control system.
"In the long term, concrete fails," warns Peter Gleick. "If we can think about a broader way of managing our water for the 21st century, we'll be much better off."