Southland storm prompts flood concerns

Steady rain again fell across much of the Southland Tuesday as a three-day storm continued to soak the region, prompting concerns about flooding in already-saturated hillsides and prompting at least one evacuation warning as authorities urged motorists to be cautious on the slick roads.

National Weather Service forecasters said the storm that began early Monday will linger over Los Angeles County Tuesday, bringing “numerous showers” that will continue into the afternoon. Afternoon rainfall totals in the county were expected to range between a quarter-inch and an inch, with the highest amounts in the San Gabriel Mountains, forecasters said.

Snow levels will remain above 7,000 feet.

“The threat of flash flooding is minimal today (Tuesday), but due to the potential for moderate to heavy rain moving in tonight into Wednesday morning, a flood watch remains in effect through Wednesday morning for most of southwest California,” according to the NWS.

The flood watch affects the entirety of Los Angeles County with the exception of the Antelope Valley. The greatest chance of showers and thunderstorms will occur Tuesday evening through Wednesday morning with the possibility of a half inch to 1 inch of rain per hour, forecasters said.

Forecasters noted there were “many reports of rockslides, mudslides and flooded roads” Monday in Santa Barbara, Ventura and Los Angeles counties.

As of 4:15 a.m. Tuesday, there had been 2.49 inches of rain reported in Beverly Hills. There was 2.24 inches of rain reported at Santa Anita Dam and 2.02 inches reported in Woodland Hills since the storm began over the holiday weekend.

There were 1.93 inches of rain reported in Santa Monica, 1.92 inches in Hollywood, 1.79 inches in La Canada Flintridge, 1.77 inches in Castaic, 1.68 inches in Pasadena, and 1.5 inches in Canoga Park.

The rain created slick and dangerous driving conditions that resulted in crashes and spinouts during the Tuesday morning commute. It also prompted some freeway closures and traffic breaks in L.A. and Orange counties.

The Sepulveda Basin — between Burbank and Victory boulevards and Havenhurst and Woodley avenue — was closed as of 4 p.m. Monday due to flooding, Mayor Karen Bass announced.

An evacuation warning was issued along Santa Maria Road north of Topanga Canyon Boulevard, southeast of Calabasas, due to possible mud/debris flows until 9 a.m. Wednesday.

Los Angeles County Public Works officials issued a “phase 2 debris flow forecast” for the Land Fire burn area east of Sun Valley. The alert will be in effect until 9 a.m. Wednesday, according to the Los Angeles Fire Department, which said moderate flooding and mudflow/sediment deposition should be anticipated in the area of McDonald Creek, Del Arroyo Drive and La Tuna Canyon Road.

“If conditions worsen, evacuation orders may be issued and evacuation sites will be identified,” the LAFD said. “Take action now to be ready to quickly evacuate if you live on the streets along La Tuna Canyon Road with the borders of Horse Haven Street to the north, Martindale Avenue to the east, Penrose Street to the south, and Ledge Avenue to the west.”

Farther south, a portion of Benedict Canyon Road was restricted to local access only due to a collapsing roadway. The “soft closure” was in effect from Mulholland Drive to Hutton Drive, with Deep Canyon Drive suggested as an alternate route.

Mulholland Drive remained closed between Skyline Drive and Bowmont Drive due to severe road damage at four locations. That closure was expected to last weeks, officials said.

The Skirball Center Drive/Mulholland Drive off-ramp from the northbound San Diego (405) Freeway was closed until further notice due to a sinkhole.

Other road closures due to flooding or debris occurred on the Interstate 5 south transition to the southbound Harbor (110) Freeway, and Second Street between Vignes Street and Garey Street.

In Rancho Palos Verdes, homeowners were dealing with reports of accelerated land movement and fears of further erosion. Los Angeles County Supervisor Janice Hahn urged Gov. Gavin Newsom to visit the area and observe the situation for himself.

“We need the governor’s help,” Hahn said in a statement. “It is my understanding that the city of Rancho Palos Verdes will be asking the governor to declare a state of emergency for the Greater Portuguese Bend Landslide Complex.

“I think if the governor came here and saw the buckling streets, the homes sinking and cracking apart, and the historic Wayfarers Chapel on the verge of collapsing, he would understand the urgency of this request. This is a crisis that is getting worse by the day, and I urge Governor Newsom to visit us and see it with his own eyes.”

Flood fears were heightened due to the region’s already soaked terrain from storms earlier this year, prompting Los Angeles city officials to put comprehensive measures in place to manage the effects of the latest storm.

The city’s Emergency Operations Center was activated to a Level 2 to monitor the impacts and coordinate the resources needed to respond to storm- related problems.

“Over the past week, the city has worked to repair more than 4,000 potholes, reinforce hills that are at risk of mudslides and prevent power outages by making repairs to underground equipment and vaults that had flooded during the previous storm,” Bass posted Sunday on social media.

As of 6 p.m. Monday, the city had responded to 27 reports of fallen trees and branches and four reports of mudslides, according to Bass’ office.

The city and county of Los Angeles activated the Augmented Winter Shelter Program to provide additional shelter options for people living on the streets. Both programs began Friday. The Mayor’s Office of Housing and Homelessness Solutions has worked to make more hotel vouchers available than previously planned to encourage unhoused Angelenos to come indoors.

Los Angeles Homeless Services Authority outreach workers began communicating about the storm and offering resources to the most vulnerable areas on Thursday with a particular focus on areas of extreme flooding like the Los Angeles River and Sepulveda Basin.

Newsom activated the State Operations Center to help coordinate state, local and federal response to the storm.

A high surf advisory will be in effect through 10 p.m. Tuesday in coastal Orange County, with waves 10 to 15 feet expected, and a coastal flood advisory is in effect until 9 a.m. Tuesday at Catalina Island.

Dry weather with warming temperatures is expected to return Thursday and Friday, before another bout of light rain next weekend.