Aerial photo by John Madonna shows temporary roads that have been cut into the Mud Creek Slide to give engineers and geologists access to the mountain of dirt and rocks. Caltrans is now planning to go over the top of the massive, million cubic yard landslide. Photo courtesy Caldrons
If you can’t beat ‘em, run over ‘em. That seems to be the conclusion that Caltrans has made in dealing with the largest landslide on Hwy 1 in California State history.
Caltrans, on Aug. 1, released its plans for dealing with the massive Mud Creek Slide, which buried the highway last May 20 under 45-feet of dirt and rocks, as more than a million cubic yards — more than 5 million tons — came down overnight, extending a new peninsula more than 300 yards into the ocean.
Caltrans’ engineers have proposed going over the top of the giant mound of debris instead of attempting to grade back down to the roadway, or tunneling through the massive wall that covers some 1,500 linear feet of roadway.
“The new roadway will be realigned across the landslide and will be buttressed with a series of embankments, berms, rocks, netting, culverts and other stabilizing material,” reads a news release announcing Caltrans’ engineers’ and geologists’ decisions. Indeed, grading work has already begun, now that the slide has stabilized.
The boss is onboard with it. “Our staff has been working hard to tackle the weather-related challenges faced by Highway 1,” said Caltrans Director, Malcolm Dougherty. “We have made tremendous progress on Pfeiffer Canyon, have opened Paul’s Slide and now we have good news on the slide at Mud Creek. Our goal is to reconnect the areas impacted by the winter storms as quickly and safely as possible.”
Paul’s slide, at Mile Marker 22 just south of Lucia and about 13 miles past Mud Creek, was cleared and the road reopened several weeks ago.
The Pfeiffer Canyon Bridge, which was damaged last January when the land underneath its columns moved and cracked the bridge supports and the deck too, is also on its way to being replaced with a new, steel frame bridge. It was brought down using excavators last February and the new steel bridge I-beam girders are being fabricated in the Bay Area and are almost finished.
It is expected to open sometime in December, and will re-link the north and south ends of Big Sur, which the bridge collapse cut in half.
Going around the mountain of debris at Mud Creek will be faster and easier according to Caltrans. “This strategy will allow Caltrans to rebuild the roadway more quickly and at a lower cost than other alternatives such as structures, a tunnel or major earthwork that places additional fill into the ocean,” the agency said.
Caltrans Dist. 5 Director, Tim Gubbins, said, “This plan is a win-win for the hard-hit Big Sur community and this pristine coastal environment. Our emergency contractor continues working dawn to dusk every day and will continue until we can safely reopen the highway.”
Caltrans has sent its initial rebuilding plan out to Federal and State agencies for review and vowed to work closely with them and the residents of Big Sur through the rebuilding.
Currently, Hwy 1 from the SLO County side is closed just past Salmon Creek, which is open along with a system of trails accessible from Hwy 1.
Until Pfeiffer Canyon Bridge is done, the only access to that center stretch of Hwy 1 is via Nacimiento-Ferguson Road, a windy, 2-lane road (one lane in some areas), which crosses the Coast Mountains from Hwy 101 near Fort Hunter-Liggett.
By Neil Farrell