Mud Creek Slide buries Highway 1 in a million tons of earth, reshapes the coastline

Just how big is the new hillside collapse at the site of the the Mud Creek Slide? So big it has buried Highway 1 in a million tons of earth and reshaped the scenic coastline.

Photos and video taken this week of the site 9 miles north of the San Luis Obispo-Monterey County line show how a wall of dirt, mud and rock gave way above the highway on Saturday and cascaded down, covering the road and piling into the ocean in a semicircle peninsula.

In a news release Tuesday morning, Caltrans confirmed the massive scale of the recent collapse, saying that “over a million tons of rock and dirt fell down the slope” Saturday, “continuing down to the ocean floor 250 feet off the shoreline.”

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And it’s not just one slide, either, Caltrans said. There are actually five slides over a quarter-mile area, four of which fell Saturday and consolidated into a single slide. The resulting wall of earth “now extends 1,500 feet in length over State Route 1 and is about 35 to 40 feet deep.”

What’s next is unclear. Even before Saturday’s slide, Caltrans had no specific timetable for reopening the road, which already has been closed at Ragged Point for months since rains caused the first damage early this year.

John Madonna — whose company, John Madonna Construction in San Luis Obispo, has been working with Caltrans on both the Mud Creek slide and Paul’s Slide about 12 miles to the north — has been flying over the sites and taking pictures of the slides since his company began working with Caltrans in mid-January.

“I think there’s been slides this big, but I don’t know that I’ve heard of any slides this big on Highway 1,” Madonna said of the latest slide at Mud Creek.

He called it “a very humbling and amazing situation.”

“We’re trying to get more scientific evidence and, with Caltrans, evaluate what to do. It’s gotten progressively worse in the last 20 to 40 days,” he said. “This time of year is when all the major catastrophic failures occur on Highway 1 historically.”

Caltrans had been working on the scenic road but suspended work and removed heavy equipment from the Mud Creek area last week because of a threat of new slides — a threat that became a reality Saturday. Caltrans said its geologists and engineers will assess the situation further once the area stabilizes.

Caltrans also reported that roadwork at Paul’s Slide has ceased because of increased activity on the hillside there.

The only access from the south to the area between the two slides on Highway 1 is via Nacimiento-Fergusson Road. Gorda services, beaches and campgrounds there remain open, but getting there across the mountains is a 2- 1/2 hour drive from San Luis Obispo.

Correction: In an earlier version of this story, the map contained an incorrect location for the Pfeiffer Canyon Bridge.

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