Torrents of rain and wind on Thursday flooded roads, knocked-out electricity and generated hazardous conditions from downed power lines to mudslides throughout Sonora and Tuolumne County.
On Highway 108, Highway 49 and Highway 120, widespread flooding buried roads under inches, and sometimes feet, of brown, muddy water.
Traffic was snarled at intersections.
State, county and city officials scrambled to clear roadways of all means of debris and redirected traffic away from the floods.
Thursday morning, urban and small stream flood advisories were issued for areas through Tuolumne and Calaveras Counties especially in areas affected by 2017 fires, said National Weather Service meteorologist Mike Kochasic.
The thunderstorms roared into the area as part of a warm atmospheric river system originating in the tropics, Kochasic said, and dropped about 1.73 inches of rain in the Sonora area, and 1.42 inches of rain in the San Andreas area.
“We’re swamped. It’s crazy over here,” said Krishna Livingston, Sonora Police Department dispatcher, Thursday morning.
Throughout the day, the Sonora Police Department coordinated resources with PG&E on reports of power outages on the west side of Washington Street, as well as with the Sonora Public Works Department, which set up and bags and cleared flooded roads from Racetrack Road, Sanguinetti Road, and the intersection of Highway 49 and Washington Street near Sonora High School.
The storm and subsequent flooding also prompted road closures throughout Tuolumne County as officials worked to clear the roads of water and debris, said deputy county roads official Duke York.
During the day, the road closures included portions of Old Priest Grade, Crystal Falls Drive West, Kewin Mill Road at Belleview Elementary School, Red Hills Road, Simms Road, Bell Mooney Road, Power House Road, Ferretti Road in Groveland and Cedar Springs Road in Twain Harte. J-59 was reduced to one-lane traffic.
“There’s a lot going on now,” York said. “This is not normal. This is a pineapple express. You have the snow and the warm rain it's like having two storms back to back.”
Kochasic said that increased snowmelt as a result of a warm rain system (with precipitation falling on icy slush in higher elevations) was overstated, but did contribute to the swelling waterways.
“It does release some of it but it doesn't melt as much as you would think,” he said. Most of the flooding and rushing creek systems would be a result of the precipitation rather than snowmelt, because the temperature of the rain would not be dramatically much higher than the snow, he said.
At about 1:30 p.m. on Thursday above Sullivan Creek near Phoenix Lake Road, two California Highway Patrol officers monitored a potentially live power line brought down by a tree and laying across the bridge.
The road was closed from Paseo De Las Portales to Belleview Creek Road, restricting access to Gold Rush Charter school, which had been evacuated at about noon for flooding.
Sullivan Creek swelled with reddish, ruddy water, flowing in heavy torrents through rocks, trees and foliage under the bridge.
Throughout the day, York said the county was “monitoring many, many locations” after reports of “trees going down or slides.”
The Tuolumne County Office of Emergency Services also offered free sand to the public in Tuolumne, Sonora, Jamestown, Columbia and Groveland to protect homes and roads from the flooding.
Caltrans District 10 Public Information Officer Warren Alford said all of Highway 108 and Highway 49 (besides the Highway 49 area near Marshes Flat Road) were open as of Thursday evening.
Flash flooding Thursday afternoon had temporarily closed Highway 108 between Pinecrest Reservoir and Strawberry, he said.
During the storm, Caltrans employees were seen clearing culverts to make sure ditches were free of debris to divert the flow of water off the roads. The workers removed boulders, downed trees, obstacles, mud and dirt that had toppled into the roadways, he said.
“We had our guys patrolling all of the routes to take care of it as quickly as possible,” he said.
The California Highway Patrol - Sonora Area responded to dozens of reports of rock and mudslides, road flooding and traffic hazards before noon on Thursday. The high volume of calls were mostly from citizen reports of traffic observations, and CHP officers had been staffed for overtime from their morning shifts to assist Caltrans and Tuolumne County officials with clean-up and traffic control.
The CHP reported a one accident before noon, a single-car accident near Rawhide Road and Highway 49.
At 11:30 a.m., Livingston said there had been no reports of traffic accidents within the city limits. Half-an-hour later, a black Jeep stalled at the intersection of South Washington Street and Linoberg Street. The ignition screamed and whined as traffic began to pile up behind it.
The driver, the passenger and some nearby good samaritans eventually pushed the Jeep to the side of the road.
The streets of Sonora were empty as the deluge overflowed gutters and waterfalls tumbled off of rooftops.
Others were forced into the storm to protect their homes.
At about 11 a.m., Keith Moniz, a resident of Racetrack Road in Sonora, furiously hacked at a drainage grate to remove debris as a stream of muddy water splashed at his ankles.
When he returned to his home with his children that morning, he said, his garage had been flooded.
“It was like a river. I started to panic,” he said.
Others, wearing hats, head scarves and ponchos, walked or carried their dogs.
The Seventh Day Adventist Church parking lot had become a churning reservoir, filling from the tributaries streaming off of Rotary Park and Dragoon Gulch.
The swift water of Sonora Creek spurred fascination, as some stopped along Coffill Park, Stockton Road or at the Mother Lode Fairgrounds to take videos on their cell phones.
“I thought it would make a good Snapchat,” said Thomas Judge of Sonora, who hopped out of his black truck to take a quick glimpse at the creek.
“It looks like it would be fun to kayak actually. It’s just pretty radical, man. That’s a lot of water.”
Livingston said Acting Sonora Police Chief Turu VanderWiel had said there would be “several feet before the creek floods.”
“First things first,” she said. “We’re trying to be productive.”
In a press conference outside of the Tuolumne County Sheriff’s Office Thursday afternoon, Tuolumne County Sheriff Jim Mele said the storm wrought “a great deal of havoc throughout the county.”
Livingston also added that PG&E had responded to “some kind of explosion” of a transformer on Linoberg Street in the morning, but could not speculate if that had caused the downtown power outage.
Many businesses, and almost all of the restaurants, along the west side of Washington Street had closed. Yoshoku had a sign on their window relating that they would be closed for the day due to the rainstorm.
Employees at the Save Mart on Stockton Road roamed the building with a flashlight and indicated that front access to the building was closed due to the sealed electric sliding doors. Perishables had been wrapped to prevent spoiling, they said from behind the darkened windows.
But some businesses intended to stay open.
Let’er Buck and Western Wear on South Washington Street was still darkened by the power outage, and manager Susie Avila said a roof leak in the back room was beginning to cause minor flooding.
“But you know what, we’re still open,” she said. “We’ve got this, we can handle this. It’s lucky we’re not made of sugar.”
Mele cautioned that Tuolumne County residents “be prepared” for upcoming weather conditions over the weekend that could prompt similar effects on county roads and waterways. Rain and snow were expected as low as 1,500 feet elevation, he said, and warmer weather expected later in the week could prompt a snowmelt that could cause flooding.
In the coming storm, Alford said “much lower chain controls” should be expected by commuters.
Several county reservoirs were in danger of overflowing during the storm, he said, but were now considered safe.