Rainstorm unleashes mud, damages downtown L.A. street

A new round of thunderstorms plowed through Southern California on Saturday, snarling traffic, threatening mudslides and opening up a large hole on a busy street in downtown Los Angeles.

The heavy band of rain drenched coastal and valley areas throughout the day, and forecasters predicted intermittent showers until the storm moves out of the region on Sunday afternoon, most likely just in time for Sunday’s Oscars show.

The storm was expected to dump 1 to 2 more inches of rain in coastal areas and 2 to 6 more inches in mountain and foothill regions. Mandatory evacuation orders remained in place for parts of Glendora, Monrovia and Azusa.

Forecasters predicted the storm will have dropped nearly 6 inches on downtown Los Angeles — and more in the mountains and hillside areas — by the time it moves on toward the Midwest and Northeast, where it is expected to generate severe ice and snow storms.

“This is no drought buster, but it’s a nice, fat down payment” in the water bank, said Bill Patzert, a climatologist for the Jet Propulsion Laboratory in La Cañada Flintridge.

Patzert said the storm, the largest since December 2010, helped put an end to an unusually long wildfire season and ease the three-year drought conditions plaguing the state. He said it would bring the Los Angeles region to about half its normal rainfall for the season; it started the week at just 10% of normal.

Gov. Jerry Brown on Saturday signed legislation to free up the state’s water supplies and help residents who face hardship because of the drought. Also, parched Sierra Nevada ski resorts got a dose of snow, enabling them to open some previously bare runs and adding to the severely low snowpack, a major source of the state’s water.

But the storm brought its share of misery in the suburban foothills of Glendora, Azusa and Monrovia, below wildfire-denuded sections of the San Gabriel Mountains.

The hills behind Ridge View Drive in Azusa were swollen with mud, threatening to damage the same homes that survived the 2,000-acre Colby fire less than two months ago.

Rain earlier in the week had sent mud coursing toward the backyards of homes nestled against the hills. Los Angeles County firefighters parked in the cul-de-sac, with heavy equipment waiting nearby, just in case.

Resident Ed Heinlein, who evacuated early Friday with five family members, returned Saturday morning to rescue Gizmo, the family cat.

“When we drove up, we knew it was going to be bad,” Heinlein said. On Friday, he said, a little mud had been strewn in the street. On Saturday, there was a lot more debris, much of it coming from his own lot.

During about 20 minutes of hard rain Saturday morning, he said, a wave of mud had rolled down the mountain, surged over a retaining wall and buried his backyard. The force of the mud bent a metal fence at a 45-degree angle. Only the net and backboard of his 10-foot-high basketball hoop were visible above the muck.

“We’ve got to find a way to get the 100 tons of mud out of my backyard,” Heinlein said. “We’re probably looking at tens of thousands of dollars in damage.”

Insurance won’t cover the damage to his home, Heinlein said — a risk the family took when they moved into the home more than 11 years ago.

“It’s a beautiful area,” Heinlein said, as heavy clouds hugged the rough hills behind him. “But if you’re going to live in an area that has these types of mountains and these types of fires, you know what can happen.”

Jeff White’s home wasn’t damaged, but he came back to the neighborhood Saturday to grab clothes from the house and check on his neighbors. He walked gingerly through the mud on the terraces, looking at avocado trees and shrubbery buried in silt.

“We evacuated in January, we evacuated in February,” said White, whose home is across the street from the mountains. “We’re just hoping March will be better.”

Elsewhere in the L.A. Basin, officials braced for high winds, wild surf, thunderstorms and even some tornadoes.

In downtown Los Angeles, a large hole swallowed a chunk of street in the 200 block of North Broadway, officials said. The hole, which developed about 11:30 a.m., was about 8 by 4 feet in diameter and about 10 feet deep, according to the Los Angeles Fire Department.

Maintenance crews were called out to assess and try to fix the damage while police officers directed traffic.

About 3,200 households in the city of Los Angeles and an additional 2,400 countywide went without electricity, mostly because of debris falling on power lines. In Riverside, about 21,000 customers had their power knocked out by lightning strikes.

Saturday evening, the 110 Freeway was closed at the 405 Freeway in Carson because of flooding. On the Central Coast, a pier at Gaviota State Park collapsed after being buffeted by large waves.

But overall, Patzert said, things were turning out pretty well.

“The urban flooding here, except in some of the burn areas,” he said, “really has been pretty minimal.”

laura.nelson@latimes.com

jean.merl@latimes.com