Caltrans says detour may be required for weeks or even months

What Caltrans officials are calling a “slipout” at the north end of the historic Red Rock Wall turnout, just north of Baylis Park, will have Highway 18 closed to all traffic between the traffic signal at Lake Gregory Drive and Pine Avenue in Rimforest for an unknown duration.

Caltrans District 8 Chief of Public and Media Affairs Terri Kasinga has said the closure could range anywhere from a few weeks to a month or longer.

The so-called slipout was first detected around 4:20 p.m. on Saturday, April 23, during a routine inspection by a Caltrans Geotech engineer. When asked how long the needed repairs would take to complete, Kasinga said they could take as long as four or five months. Asked how much the repairs might cost, she said it could be as much $5 million, which exceeds the $4.2 million paid to Skanska Construction to repair last December’s Highway 18 washout near Panorama Point.

Kasinga added that last week’s heavy rain and snow may have contributed to the recently discovered slippage.

Caltrans Public Information Officer Emily Leinen, who arrived at the incident scene shortly after 11 a.m. Saturday, told The Alpine Mountaineer that the slip basically means that the shoulder or the slope is essentially slipping away from the roadway.

“This is kind of the beginning of a washout, and it’s lucky that we caught it relatively early. The washout we had back in December was a full roadway washout,” Leinen said. “We lost the lanes, and we lost the road. This is the difference between a washout and a slip.”

Leinen said the wall is starting to pivot and starting to move away from the actual slope, which means the wall is essentially failing. This would explain why two Caltrans workers were seen Saturday morning at the scene of the slipout, which they had identified with orange lines painted on the pavement. They were carefully watching the area in case there was any additional slipping. Meanwhile, a Caltrans Geotech engineer was carefully monitoring the soil beneath the wall.

“Right now,” Leinen said, “we have the road closed in both directions. We have a detour available. The detour is the 189 (Highway 189). All motorists will be directed to go over the 189. However, if you are a big rig, a large bus or a truck with a heavy trailer, please use Highway 330 to go around this (the slippage area),” she said, adding that Highway 189 is a very difficult road to drive on due to all the very steep and winding curves.

Asked how long the closure might last, Leinen said, “We do not have an estimation of how long those repairs will take. We are going to do an emergency director’s order to get a contractor up here to fix it and get it all stabilized. We are still doing a lot of evaluation, so we don’t know a whole lot right now. We need to figure out all the damage and go from there.”

Many motorists may have noticed a slight dip in the pavement, which has existed for the last 12 years or so at the north end of the Red Rock Wall, just past a wedge-shaped, earthen cavern, approximately eight feet long and two feet wide back under the wall face and one foot tall beneath the wall. This dip was discovered 12 years ago and written about in a front-page article that appeared in The Alpenhorn News (a predecessor to The Alpine Mountaineer) on April 15, 2010. A Caltrans spokesperson at the time said, “The gap is some minor settlement and nothing to be worried about.”

Motorists may recall, back in 2010, when a drilling rig was taking core samples along the outer edge of the highway. Caltrans spokeswoman Terri Kasinga told The Alpine Mountaineer at the time that the crew was drilling to verify a road slippage issue that had existed for several years. Last Saturday, Kasinga said she doesn’t believe the cavern, which had been boarded up with plywood sheeting, poses any imminent danger.

The Alpine Mountaineer advises all motorists to adhere to the recommended detour routes, until repairs to the slipout zone are completed.