Northern California braced for major flooding and widespread power outages late Monday as large amounts of rain fell on swollen rivers
About 15 monitors along the Sacramento, San Joaquin, Cosumnes and other rivers showed water levels at or heading toward flood stage Monday afternoon, according to the California Nevada River Forecast Center.
As evening arrived, officials ordered a mandatory evacuation after a levee broke in San Joaquin County south of Manteca. Police in Lakeport, northwest of Sacramento, reported they needed a canoe to contact some residents in a flooded area.
By 7:30 p.m., rainfall totals in Sacramento stood at a record-breaking 1.66 inches, with more on the way. Winds were less fierce than expected, topping out at about 35 miles per hour near the Sacramento Executive Airport and expected to hit highs in the mid-forties, according to Johnnie Powell, a forecaster for the National Weather Service in Sacramento.
Precipitation amounts were higher in the foothills and the Sierra.
Forecasters had predicted wind gusts up to 60 mph Monday night throughout the Central Valley. Gusts that strong typically cause tens of thousands of homes and businesses to lose power.
It’s a familiar story so far this year: After a long drought, Northern California has gotten the rain it wanted – and a lot more.
Much of California, including Sacramento, is on pace for the wettest year on record, setting the stage for flooding. Sacramento has seen more than 26 inches of rainfall since Oct. 1, double the amount usually seen at this point in the year. Localized flooding has been commonplace, though so far Sacramento and Northern California have not experienced widespread, catastrophic floods.
It came close last week, when officials evacuated about 180,000 people downstream from Lake Oroville after a huge crevice developed in the lake’s main spillway and its emergency spillway appeared on the brink of failure.
Emergency officials remained at the lake Monday, though the situation appeared less dire than it did eight days ago.
Water levels at Lake Oroville fell below 850 feet early Monday, the flood-control stage that officials normally want to keep the lake below this time of year, state figures show. Levels were holding steady Monday afternoon. Still, Butte County is leaving an evacuation warning in place while crews continue to repair the damaged Oroville Dam spillways through a wet winter storm.
Sheriff Kory Honea said there was “no immediate threat” that a spillway would fail, but he chose to maintain the warning in case conditions change.
The warning encourages residents to be ready to leave town on a moment’s notice, as they were instructed to do on Feb. 12, when officials feared the dam’s damaged main spillway would fail.
“I am moving cautiously because I want people to be paying attention,” Honea said. He said the county is working with the California Department of Forestry and Fire Protection to revise evacuation plans for Oroville.
“My plan is that, should the risk begin increasing, people can expect us to give them that warning much earlier.”
Officials in Butte County opened evacuation centers Monday in Chico and Oroville for residents affected by localized flooding. A separate evacuation facility in Chico opened last week – and is the site of a suspected Norovirus outbreak that infected about 20 people. Officials say ill evacuees at the center have been isolated and about 100 people remain.
Despite increasing rain, crews worked Monday to shore up Lake Oroville’s damaged spillways. They laid rock and concrete at the base of the dam’s emergency spillway. The reservoir is expected to rise up to five feet over the next day, although it would remain well below the lip of the dam’s emergency spillway. The water level is about 52 feet below the top of that spillway.
Separately, crews are dredging debris along a shoreline near the dam’s shuttered power plant. It may take several days before the state can direct barges to the power plant to clear the bulk of the debris and allow the turbines to return to operation, which would allow officials to release water faster.
At least one boat tried to navigate the current below the dam’s spillway Monday. It turned back.
The large majority of Northern California is under a flood warning until Thursday. Forecasters expect many Northern California rivers to crest in the next day or two as runoff makes its way into the Central Valley.
About 100 residents of Lakeport faced a mandatory evacuation on Monday afternoon. Lakeport city spokesman Kevin Ingram said the evacuations were a precaution after a wind warning made city officials fearful that mobile home communities on the edge of Clear Lake could be hit with big swells.
But Lake County Sheriff Brian Martin said that as of 7:30 on Monday night, “the wind seems to be taking it easy on us,” and no damage had been reported. A 4.2 magnitude earthquake also struck near the Lake County city of The Geyers on Monday evening, but Martin said it had caused no reported injuries or damage.
In Modesto, residents fretted as officials opened the controlled spillway at Don Pedro Reservoir. The reservoir was essentially full Monday. Turlock Irrigation District spokesman Calvin Curtin said the spillway was operating with no problems and the resevior was releasing about 18,000 cfs on Monday night. Curtin said the downstream flow of the Tuolumne River could rise by as much as five feet in coming days, bringing it up to about 59 feet. Flood stage is 55 feet. The river peaked at more than 70 feet during the floods of 1997.
Curtin said water release from San Pedro would depend on weather this week.
“To borrow from the Oroville (spokesman), Mother Nature is sitting at the table and she has a very loud voice,” said Curtin.
Stanislaus County Sheriff Adam Christianson said, “We know the rivers are going to rise ... We are not implementing mandatory evacuations. We are simply encouraging people to seek shelter and move to higher ground.”
In Colusa County, floodwaters receded some from the weekend, when the small town of Maxwell – and part of Interstate 5 – took on water. “Everybody is just waiting to see what the storm gives us,” said Colusa County Sheriff’s Department spokesman Lt. Neil Pearson.
As emergency officials braced for flooding, power companies braced for a slew of predicted outages across Northern California.
Wind gusts at 60 mph were forecast from Stockton to Redding. Less powerful gusts last week knocked out power to more than 45,000 SMUD customers. SMUD officials warned customers Monday afternoon that they expected outages and asked for patience as their workers tried to safely repair downed power lines.