Torrential rains and extreme flooding have torn open a huge hole in the Oroville Dam, as California “extreme drought” conditions plummeted from 62 percent a year ago to less than 1 percent.
The only sliver of extreme drought left in the California is Santa Barbara, where County Flood Control officials expect to experience 1 to 2 inches of rain through Saturday as another moisture-laden Pineapple Express continues to hammer California.
Unusually warm temperatures of up to 47 degrees in Lake Tahoe are quickly melting the 1 to 3 feet of new snow as the National Weather Service has issued avalanche, flooding, mudslide and high wind warnings along the Sierra Mountains. The Weather Service expects deteriorating conditions Thursday due to 25-to-35 mph winds and gusts up to 75 mph.
With water flowing into Oroville Dam at a rate of 83,000 cubic feet per second, officials opened the spillway. But a flow of 55,000 cubic feet per second tore a 200-foot-long, 30-foot-deep hole in the spillway as massive amounts of water and chunks of concrete surged down the Feather River. Numerous mudslide and washouts were reported downstream.
Acting director of the Department of Water Services Bill Croyle said in a Wednesday press conference that the hole does not create any “imminent danger,” according to the San Jose Mercury News. But he added, “We wouldn’t be surprised if by the end of this wet season much of the lower portion of the spillway has been eroded away.”
Central Nevada’s Twentyone Mile Dam also broke on Wednesday, prompting the National Weather Service to warn, “Residents living in Montello and near and downstream of and Thousand Springs Creek should take immediate action to protect life and property.”
Interstate 80 westbound over Donner Pass was closed due to a mudslide at Stateline. The local sheriff’s department called the record rapid snowmelt and subsequent flooding a “life-threatening” situation and warned motorists to refrain from driving on flooded roads.
U.S. Highway 50 is completely closed near the Cave Rock area east of Lake Tahoe following three days in which large boulders fell onto the road. A section of State Route 828 was closed due to a downed power lines, and a mudslide in Shasta County shut down the southbound lanes of I-5 near Lakehead.
Los Gatos resident Jennifer Ray issued a Facebook Alert that “everything’s being destroyed,” according to local Fox affiliate KTVU, as a mudslide washed away three houses on her family’s property. Although no one was hurt, Ray told NBC News, “All of this water and mud came down and trees and it was just this force of nothing that I’ve never seen before.”
Twenty miles away on Skyland Road near the Santa Cruz mountain summit, a man who had driven safely to the store to buy candles, drove his van into a 100-foot washed out section of the road on the way back home.
Weather.com meteorologist Chris Dolce commented that with much of the ground in California already saturated, warnings have been posted from Washington State southward into northern and central California, due to the risk of additional landslides and flooding remaining elevated for the next week.