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Big Sur’s brave new route crosses epic Highway 1 landslide

Crews are planning a route across the loose debris field created by the Mud Creek Slide on Highway 1. It’s one of California’s largest coastal landslides in recent history. This photo shows the slide and route on Tuesday, June 13, 2017.
Crews are planning a route across the loose debris field created by the Mud Creek Slide on Highway 1. It’s one of California’s largest coastal landslides in recent history. This photo shows the slide and route on Tuesday, June 13, 2017.

California’s restless new stretch of beachfront property in Big Sur will soon have a road.

To erect motion-sensing radar out on the tip of a 13-acre peninsula created by the dangerous Mud Creek Slide on Highway 1, crews are planning a route across the loose debris field created by one of California’s largest coastal landslides in recent history.

There also are plans to start excavation on the southern side of now-buried highway just north of the San Luis Obispo County line in order to build a ledge for construction equipment.

“We’re trying to find stable ground. We are pioneering a road,” said John Madonna of John Madonna Construction Co. of San Luis Obispo, which will conduct the Caltrans project to open the Big Sur stretch of road.

The new radar system will be installed atop what’s been dubbed “Pyramid Rock,” a barn-sized boulder at the edge of the new apron of coastline that’s the size of 10 football fields.

It can detect mere inches of movement on the restless mountain and quickly transmit its data by satellite to experts in Colorado for analysis, Madonna said.

If the radar senses sudden motion, it sounds an alarm.

Madonna will rely on the radar to protect his crews; Caltrans will use it to plan route construction.

While there is an existing radar system near the mountain, its angle is very oblique and can’t evaluate the entire terrain, he said. The new system utilizes different and more innovative technology by a company called IDS GeoRadar, which specializes in mine safety.

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After this winter’s fierce rains, Madonna and a team of experts with Caltrans and the U.S. Geological Survey watched and worried over five distinct slides on the steep 1,100-foot mountain.

Noticing movement, they pulled workers off the main section of the site May 17. Then, two days later, on May 19, they stopped work on the edges of the site, as well.

It undoubtedly saved lives: On the night of Saturday, May 20, three of the five slides suffered a dramatic collapse, dropping 2 million cubic meters of earth, according to the U.S. Geological Survey. That’s 200,000 dump trucks filled with rubble.

While much of the Mud Creek mountain now seems quiet, two weak spots remain at risk of sliding: one on the north, the other on the south.

The greatest concern is a steep and unstable northern flank of the mountain range. It is not yet considered safe for construction.

“The north end of the slide is still hanging up there,” Madonna said. “Otherwise, most of the energy of this thing has dissipated.”

He also monitors the mountain from the air, photographing it from his Piper Saratoga plane.

Highway 1, if it still exists, is buried under 80 feet of dirt and rock at its deepest point. That’s a formidable excavation project. It may take more than a year to reopen the road.

As Madonna looks in awe at the dramatic shifting landscape that has buried an iconic coastal highway, he thinks of the words of his father — the late real estate developer and entrepreneur Alex Madonna, who founded the Madonna Inn with his wife, Phyllis.

“My father always said about the California coast: ‘They don’t make any more of it,’ ” he said. “But here it is.”

Contact Lisa M. Krieger at lkrieger@bayareanewsgroup.com.

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