An “atmospheric river” continued to batter parts of Northern California on Tuesday, causing widespread flooding.
The heavy rains prompted the National Weather Service to warn of a dam failure outside Carson City, Nev., saying that it was “not a drill” and that residents should “move to higher ground now.”
But less than 90 minutes after issuing the alert, the agency changed its report to say the retention basin in Dayton, Nev., had not failed. Instead, it was full and overflowing into drainage areas, the weather service said.
However, Lyon County, Nev., emergency officials warned that the situation could change in the next few hours.
Dayton, Nev., with a population of about 9,000 people, is about a 13-mile drive northeast of Nevada’s state capital, Carson City.
The rains continued to pound the region a day after water gushed down from Don Pedro Dam in Stanislaus County for the first time since 1997.
The Don Pedro release came on the heels of the crisis that developed just over a week ago at Oroville Dam. Both of the dam’s spillways were damaged, and fears of catastrophic flooding prompted the evacuation of more than 100,000 people.
Turlock Irrigation District officials said Monday that the structural integrity of the Don Pedro dam and spillway were “not in question,” and that the amount of water being released would be far less than in 1997, when major flooding occurred. On Tuesday, the district said that water was being released from the Don Pedro Power Plant and that the spillway was operating as designed.
Runoff from a weekend of powerful storms peaked Tuesday across central and Northern California, pushing water through aged levees and spilling over small local dams.
In San Jose, city officials declared a local emergency after streets became flooded as water levels rose along Coyote Creek. San Jose firefighters waded through flooded streets in rafts, rescuing residents trapped in their homes and in trees in the Rock Springs neighborhood. Those who walked through dirty floodwaters were hosed off and decontaminated, officials said.
Officials issued mandatory evacuations for 300 homes in the neighborhood, where water was waist-high in some streets, said city spokesman David Vossbrink. At least 40 people were evacuated to an overnight shelter.
“We haven’t really had anything quite like this before,” he said.
The last time San Jose experienced severe flooding was about 20 years ago, Vossbrink said.
The creek runs for 30 miles through San Jose, he said. Flooding varies from street to street due to the changing topography in each neighborhood, Vossbrink said.
“It’s really a complex hydrological issue,” he said.
However, water levels should start receding by midnight, Vossbrink said. After the water retreats, officials will go door-to-door to assess damage to homes, city buildings and other facilities, he said.
The Anderson Dam in Santa Clara County reached capacity Saturday about 5 a.m., according to the California Department of Water Resources.
But it wasn’t until a downpour Sunday night and Monday morning that water began flowing over its wall and into Coyote Creek.
The flow of water into the dam peaked Tuesday afternoon, department spokeswoman Maggie Macias said. Coyote Creek then flooded lanes on the 101 Freeway and triggered evacuations in low-lying areas.
The worst of the runoff also hit Shasta, Folsom and Oroville reservoirs Tuesday, but no problems were reported.
The Tuolumne River also was seeing its biggest surge of water Tuesday, Macias said.
Residents living along the Tuolumne River in Modesto were continuing to prepare for rising floodwaters Tuesday morning.
Dylan Douglas Hamlin, 21, was spending the morning packing his remaining belongings to leave the Driftwood Mobile Home Park in Modesto, which sits along the riverbanks.
“We lost all of our stuff, man,” Hamlin said. “We lost our clothes, our shoes.”
Hamlin hoped to drive the trailer to higher ground by noon, just as emergency officials are expecting the river to continue its swell above flood stage.The rising water was the result of continued storms in Northern California and the release of water down the spillway of Don Pedro Dam for the first time in nearly two decades.
Katie Whitley, who manages the mobile home park, said people nearest the river have been moving their trailers out since the start of the weekend. Residents had fled about 15 of the park’s 74 spaces by early Tuesday, she said.
“We’re just holding our own,” Whitley said. “That’s what we have to do. You just have to hope for the best. But you can expect it when you live on the river.”
Stanislaus County sheriff’s deputies were at the park Tuesday morning and have been notifying residents and others living nearby of the flood risk and potential power outages, department spokesman Sgt. Anthony Bejaran said.
On Tuesday, dramatic gusts were recorded by sensors in the Lake Tahoe Basin, where Ward Peak had a 199-mph gust, according to the weather service. Sierra Crest recorded 193 mph, and Biggs had 184 mph.
“Wind speeds that high are pretty rare — extremely rare,” said National Weather Service meteorologist Hannah Chandler.
Chandler cautioned that preliminary wind speed measurements could later change as the weather service assesses the data.
Dillon reported from Modesto, Serna from Sacramento and Sahagun from Oroville.
5 p.m.: This article was updated with comment about flooding and evacuations from David Vossbrink, a spokesman for San Jose.
2:40 p.m.: This article was updated with the National Weather Service saying the retention basin in Dayton, Nev., had not failed.
1:55 p.m.: This article was updated with flooding in San Jose and warnings of an imminent retention basin failure in Dayton, Nev.
11 a.m.: This article was updated with scene details near Modesto.
This article was originally posted at 8:50 a.m.