Mudslides, power outages after storm slams northern Nev., Calif.

RENO, Nev. -- A powerful winter storm packing winds in excess of 90 mph toppled semi-trailer trucks, knocked down power lines and triggered flooding and road closures on Thursday. 

Rockslides and mudslides closed roads and state highways around Lake Tahoe, and Elko County declared a state of emergency due to flooding after an earthen dam burst in northeast Nevada, washing out a section of State Route 233 and forcing its closure from Montello to the Utah line.

More than 10,000 homes were without power late Thursday afternoon along the Sierra’s eastern front from south of Carson City to north of Reno. NV Energy reported most of the outages were in Douglas County near Minden and Gardnerville where downed power lines closed a local road.

The high winds also snapped several large trees in the area, including one that landed on an unoccupied car in Carson City.

There were no immediate reports of any injuries.

A flood warning and high-wind warning remained in effect into Friday for most of the region. A wind gust in excess of 100 mph was recorded at the top of the Squaw Valley ski resort north of Lake Tahoe early Thursday, the National Weather Service said. A 92 mph gust was recorded southwest of Reno.

The Nevada and California Highway Patrol responded to at least a half-dozen reports of semi-trailer trucks blown over by the winds on U.S. Highway 395 south of Carson City and north of Reno, as well as south of the California-Nevada line near Lee Vining and north of Reno on California Highway 70 at the Hallelujah Junction near Portola.

A stretch of Interstate 80 west of Reno was reopened early Thursday after a mudslide closed the westbound lanes overnight near the California-Nevada line. Three cars were stranded, CBS affiliate KTVN reports. 

“We’re looking at about 300 yards of material on the side, which decided to wash down a little mud flow,” said Pat Day of Caltrans told KTVN. “It’s been known through these canyons that they have mudflows every now and then.”

Floodwaters a foot deep covered some streets in South Lake Tahoe, California, and a stretch of U.S. Highway 50 remained closed on the lake’s east shore near Cave Rock where a series of rockslides halted traffic Wednesday.

“Since Monday, we’ve had five very large boulders come down, literally the size of busses,” Nevada Department of Transportation spokeswoman Meg Ragonese told The Associated Press. “Luckily, no vehicles were involved.”

“Now, we have a very big, round rock at the top of the slope that gives indications it is going to come down, so the road remains closed” indefinitely, she said Thursday afternoon.

East of Carson City, U.S. Highway 95-A was closed between Yerington and Schurz due to high winds and blowing dust. In northeast Nevada, a 65-mile stretch of U.S. Highway 93 was closed due to flooding from Interstate 80 at Wells north to the Idaho line at Jackpot.

“With this continued precipitation, we’ve really had an impact across the entire stretch of northern Nevada,” Ragonese said.

Elko County Sheriff Jim Pitts said county commissioners approved the state of emergency as his deputies searched for anyone who might be stranded by floodwaters. No injuries have been reported, but authorities said there appeared to be extensive damage to several ranches and farms.

About 30 residences have been impacted by the floodwaters in Montello since the Twentyone Mile Dam broke Wednesday afternoon, Pitts said. A 10-mile stretch of State Route 233 remained closed.

The flooding in Elko County forced delays or rerouting for more than a dozen freight and passenger trains on a main rail line that runs through the area, said Union Pacific spokesman Justin E. Jacobs. A Nevada postal spokesman told the Elko Daily Free Press that the Montello Post Office was “swamped,” but workers were able to retrieve all the mail.

“We’re still assessing how we’re going to deliver it,” David Rupert told the newspaper.