Topanga Canyon Blvd. to Be Closed for Days Due to Mudslide as Storm Moves Through SoCal

Rain and snow fell in Southern California Thursday morning, making for difficult driving conditions and prompting a mudslide that has forced the dayslong closure of Topanga Canyon Boulevard east of Malibu.

A mudslide closed a portion of Topanga Canyon Boulevard on March 15, 2018. (Credit: Al Seib / Los Angeles Times)

A mudslide closed a portion of Topanga Canyon Boulevard on March 15, 2018. (Credit: Al Seib / Los Angeles Times)

The storm, which arrived Wednesday night, is the latest in a series of weather systems slated to bring rain to the region through next week.

About one-third to three-quarters of an inch of rain had already fallen on most areas south of Point Conception by Thursday morning, according to the National Weather Service. Some foothill areas saw amounts near one-inch. Snow levels dropped as low as 4,500 feet with several mountain locations receiving a couple inches of snow.

Showers are expected to taper off by late Thursday morning, the Weather Service stated.

In Topanga, South Topanga Canyon Boulevard had to be shut down in both directions from Pacific Coast Highway to Grand View Drive due to a mud and rock slide that occurred about 2 a.m. at mile marker 1.5.

One vehicle got stuck in the mud but there were  no injuries, Caltrans said.

It's the third slide along the winding roadway through the Santa Monica Mountains since a fire burned in the area in January, the agency said.

"After the ground became saturated in a former burn area, large rocks, mud, debris, and ash slid down the slope and over the gully and roadway shoulder," Caltrans said in a news release. "A drainage pipe at that location became clogged with mud and debris and the overflow spilled onto the roadway."

The debris came down near a slide that occurred the previous week – an incident that prompted the installation of K-rail and fencing to catch future slides. Thursday's slide fell just outside the K-rail, in three spots along a 1,000-foot span, Caltrans said.

With more rain expected over the weekend, the stretch of roadway – nearly 4 miles long – will be closed until at least Sunday night, Caltrans said. No homes or businesses are on the stretch, which Caltrans referred to as a "rural area."

Caltrans advised use of PCH, the 101 and 405 freeways, and State Route 23 as alternate routes.

A second storm expected to arrive Friday is likely to bring only light to moderate showers. But a third storm is slated to arrive next Tuesday and bring a chance of moderate to heavy showers.

This storm has officials concerned about the possibility of significant debris and mud flows in the recent burn areas.