Winter Runoff Straining Delta's Levees
DISCOVERY BAY (CBS SF) -- For engineer Christopher Neudeck, the levee reinforcement near Discovery Bay is just one small piece of a giant challenge left by an extraordinary winter.
"If that levee were to fail, the lake, the golf course, the commercial area in here, that would all go under water" says Neudeck, pointing to a map of Discovery Bay in his Stockton office.
The last time KPIX covered his team at work was mid-winter, repairing a delta levee that almost failed on Tyler Island. Now it's late June, and a new risk is flowing along California's levees.
The state is experiencing what Neudeck calls a "very unusual year. The snowpack has been really prolonged."
Managing that melting snowpack means many of rivers are rising, falling, and rising again, putting a unique kind of stress on levees as they get soaked, dry out, and then get soaked again.
"That's a problem," Neudeck explains, "you're re-wetting things that were starting to dry so we could see some erosion."
It's the same problem residents saw on a large scale after the Oroville Dam scare.
To inspect the damaged spillway, dam managers dramatically cut water releases and had a "rapid draw-down" down stream on the Feather River. The sudden drop in water levels caused parts of downstream levees to slide into the river channel.
Now many of California's levees face a similar threat, only at a slower speed, heavy summer runoff on the heels of a brutal winter. Of course, levees can also fail for seemingly no reason at all, much like Jones Tract near Stockton in 2004.
"That's the best we can call it," explains Neudeck, "it's an anomaly."
So the winter keeps testing California, and as we close in on July, the engineers who maintain the state's levees are already worrying about the next round of storms.
"You really have to recognize these conditions. you're out there on earth and fill," says Neudeck. "We are scouring these levels now, because we are afraid of next winter."
