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Storms Unleash Floods and Mudslides on Northern California and Nevada

The most powerful in a series of winter storms lashed Northern California and Nevada on Sunday with heavy rains and strong winds, causing widespread flooding, downing trees and unleashing mudslides.

By Tony Barboza, Paige St. John, Louis Sahagun and Matt Hamilton

The most powerful in a series of winter storms lashed Northern California and Nevada on Sunday with heavy rains and strong winds, causing widespread flooding, downing trees and unleashing mudslides.

Tens of thousands of households lost power. Stranded motorists were rescued from rising floodwaters. And near Lake Tahoe and elsewhere in the northern Sierra, rain soaked the snowpack, increasing the risk of avalanches.

Emergency officials issued voluntary evacuation orders to hundreds of households along the Russian River in Sonoma County and the Truckee River in Reno as the rivers reached the flood stage.

Perhaps most worrisome, the storm is one of a string that is expected to continue dumping more rain and snow through Thursday, part of a so-called atmospheric river of moisture known as the Pineapple Express.

"This is a serious situation," said Mark Faucette, a National Weather Service forecaster based in Reno. "There's a significant threat to life and property as we go through the next couple of days with widespread flooding, continued road closures and high water in low-lying areas."

At least one death is suspected of being weather-related. A woman was killed in the East Bay suburb of San Ramon on Saturday when she was struck by a falling tree at a golf course amid heavy winds.

On Sunday, officials reported scattered flooding and mudslides throughout Northern California, notably in the North Bay, where several creeks and rivers were rising quickly. Motorists had to be rescued on the 101 Freeway in Sonoma County when the highway flooded. Several smaller roads were also closed because of flooding.

A major mudslide on Donner Summit early Sunday evening closed both directions of Interstate 80 in the Sierra Nevada, cutting off the main transportation route between Reno and San Francisco.

California Highway Patrol Officer Peter Mann said the flow of mud and rock extended across the road for about the length of a football field, at times 7 feet deep. Downed power lines complicated cleanup efforts and the road was expected to remain closed for hours, if not until Monday morning.

By then, it would be snowing thick enough to require chains for passage.

"The mess just keeps getting better," Mann said.

Local authorities were watching rising water levels at several key rivers, including the Merced, Napa and American.

The Truckee River topped its banks Sunday afternoon, submerging picnic tables on riverside campgrounds along Highway 89 north of Lake Tahoe. Forecasts from the U.S. Geological Survey called for the river to rise another 3 feet, imperiling private bridges to cabins alongside both banks.

Along the banks of the Truckee in Nevada, nearly 400 homes were voluntarily evacuated Sunday due to widespread flooding that is expected to worsen overnight and into Monday.

Officials expected the Truckee River to crest up to 2 feet beyond flood stage by 10 p.m. on Sunday in Reno and reach its highest level at 6 feet above flood stage by 7 a.m. Monday in neighboring Sparks.

Along the Russian River in Sonoma County, about 650 homes and a handful of businesses in the low-lying areas of Monte Rio and Guerneville were advised to evacuate. County officials expected the river to reach flood stage late Sunday and stay at flood levels through Tuesday.

The powerful storms are the latest in a series of weather systems that are beginning to make a dent in California's six-year drought. Wet weather in Northern California has filled reservoirs and slowly boosted the Sierra Nevada snowpack, which is a key source of water for cities and farmlands.

Officials said the drought still persists but that 2017 could mark a turning point if the deluge of rain and snow continues into the spring.

It remains drier in Southern California, but that region has seen decent rainfall over the last month. Rain was expected to roll into the Southland late Sunday and early Monday, bringing up to 2 inches of rain to Los Angeles County and potentially disrupting the morning commute.

The rainfall totals in Southern California were less than in the northern parts of the state, but officials said that the speed of the downpour _ up to a half-inch per hour _ elevated the risk of flash floods and mudslides.

More than 91,000 PG&E customers in Central and Northern California were without electricity as of Sunday afternoon as rain, snow and winds caused flooding and knocked down power lines, said PG&E spokesman Paul Doherty.

Those who lost power were spread across PG&E's service area, which stretches from Bakersfield in the south to Eureka in the north.

Several school districts, such as the Palermo Union School District in Palermo, about 60 miles north of Sacramento, canceled classes on Monday due to anticipated flooding on roadways.

In Nevada, where Gov. Brian Sandoval issued a state of emergency, Washoe County officials asked residents to stay home Monday, when courts and several government offices were closed. Local high schools were quickly transformed into evacuation centers.

The storm toll included one of Calaveras County's oldest residents, a giant sequoia called the Pioneer Cabin for the tunnel that had been carved into its broad base 137 years ago. It was located in Calaveras Big Trees State Park and toppled Sunday during the storm.

"We lost an old friend today," wrote county resident Jim Allday, who posted a picture of the fallen titan on Facebook. His photos show the tree trunk splintered heavily at its base.

As heavy rain fell Sunday, melting mounds of piled-up snow and sending water and slush into the streets of the eastern Sierra Nevada ski town of Mammoth Lakes, residents girded for flooding.

"My garage is flooding with 2 inches of water," said Nick Criss, 40, as he shoveled sand into bags at the town's public works yard.

Criss, a 12-year Mammoth Lakes resident, worries that his home and many others will be damaged by the gush of rainwater and melted snow.

"There's nowhere for the water to go," he said.

Lifts at Mammoth Mountain resort were not operating Sunday because of high winds, thunder and lightning.

Erik Radatz, 45, rushed to shovel sand into sandbags to protect his home. His advice for anyone from Los Angeles thinking of heading up to Mammoth?

"Stay home," he said. "But if you do come, don't bring skis _ bring water skis."

(Barboza and Sahagun reported from Mammoth Lakes, St. John from Truckee and Hamilton from Los Angeles. Times staff writers Deborah Netburn and Soumya Karlamangla contributed to this report.)

(c)2017 Los Angeles Times

Caroline Cournoyer is GOVERNING's senior web editor.
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