Another storm pounds Los Angeles County, triggering flood watch and fears of mudslides

The weather service has received reports of mud and debris flows and flooding in the Santa Monica Mountains and the Pacific Palisades area. Most of the reports have been in Santa Barbara County, where the rainfall totals have been higher.

“Usually when we start to get rainfall totals for the season above 10 inches, the areas that are really vulnerable to mudslides and landslides become especially vulnerable to those type of issues,” Kittell said.

Residents of Rancho Palos Verdes, where a slow-moving landslide complex has been shifting for decades, are bracing for the aftermath of this week’s storm. Although only about 1 inch of rain has fallen in the area, record-setting rainfall over the past several months has saturated the ground, causing the landslide area to shift more rapidly, according to City Manager Ara Mihranian.

“In some areas, (the land) is moving up to 10 feet a year,” he said. “That’s significant movement, and we’re seeing the damage that’s being sustained throughout the community. We have approximately 400 homes that are threatened by this landslide.”

Two homes have already been red tagged, and other residents have reported sinkholes, cracks in their walls and doorways that have split. The pavement on Palos Verdes Drive South, a major roadway through the community, is buckling.

The Rancho Palos Verdes City Council on Tuesday is set to consider asking Gov. Gavin Newsom to declare a state of emergency in the city, an effort that could help them fast-track a $33 million landslide remediation project to stabilize the area.

In past storms, landslide damage has occurred sometimes months after the wet weather subsides.

The early February storms drenched much of the state in historic rainfall, knocking out power for hundreds of thousands of people, flooding neighborhoods and triggering mudslides. Several people in Northern California were killed in the onslaught.

Those storms hit certain neighborhoods particularly hard. Nearly 14 inches fell on Bel-Air over five days. So much rain in such a short period of time can be catastrophic for densely constructed hillside neighborhoods.

For the most recent storm, Los Angeles County authorities issued an evacuation warning for Santa Maria Road north of Topanga Canyon Boulevard through 9 a.m. Wednesday because of possible mud and debris flows.

A large sinkhole has also closed down the Skirball-Mulholland northbound 405 Freeway offramp indefinitely while crews make repairs, according to the California Department of Transportation.

Portions of the 101 Freeway from Seaward Avenue to California Street in Ventura are closed on account of flooding, according to Caltrans.

Highway 1 is closed from 6 p.m. to 7 a.m. in both directions from Sycamore Canyon Road to Las Posas Road in Ventura County because of erosion on the southbound shoulder.

Highway 150 is closed in both directions between Stonegate Road and Topa Lane because of slides and storm-related damage.