Long closures at Last Chance Grade will finally come to an end this Monday.
The small stretch of Highway 101 between Crescent City and Klamath, known as Last Chance Grade, has been hampered with long work closures since a landslide swept over the road in February. In July, CalTrans extended daily closures from two to four hours in an effort to speed up the clean-up operation — a move that worked according to Sebastian Cohen, project manager with CalTrans.
“We’ve met our goal of removing all of the material, which was the critical thing to do with these four-hour closures, the rest of the work can be done from a closed lane,” said Cohen. “It’s a challenging site with very limited room. We love to keep traffic going and we would have if we could, but for everyone’s safety we had to do it this way.”
Remaining work at Last Chance includes completing the installation of a special mesh, which is designed to knit together the slope to prevent a future catastrophic slide, as well as catch any falling debris, according to Cohen. So, while the road will remain open to one-lane traffic at all hours of the day, motorists should still expect up to 30-minute delays.
What’s more, a separate project just a couple hundred feet away from the landslide cleanup is expected to wrap sometime in the fall of 2022, meaning, Last Chance Grade could open up to two-lane traffic for the first time since 2014.
While the end of long work closures will come as a relief to many Del Norte residents, the fix is not meant to be long-term. Earlier this year, though, CalTrans and other contributing agencies zeroed in on two possible solutions to the Last Chance Grade problem: Alternative F and Alternative X.
Alternative F proposes a half mile tunnel into the slope intended to avoid the landslide hazard altogether. While the tunnel carries a hefty price tag with an estimated $1.3 billion in construction costs, it would also have the smallest environmental footprint out of the remaining alternatives, according to CalTrans. The estimated construction schedule for Alternative F is seven years.
The proposed tunnel would be similar in length and features to the Tom Lantos Tunnels at Devil’s Slide on Highway 1, south of Pacifica in San Mateo County, California.
Alternative X is a cheaper solution, and a little more complex. Alternative X proposes an “end-to-end” re-engineering of the current alignment of Highway 101, intended to mitigate the landslide hazard. A re-engineering would include moving the road slightly east in key locations, dewatering the slope to minimize movement, additional retaining walls, and regrading the adjacent hillside to a flatter angle. The estimated price tag for Alternative X is $500 million and the estimated construction schedule is 3 and a half years.
Del Norte County Supervisor Bob Berkowitz said he’s skeptical of both remaining alternatives.
“I don’t put faith in either one of them,” he said.
Berkowitz said the state will probably not fund a project as expensive as Alternative F, and Alternative X seems unlikely to fix the inherent problems at Last Chance.
“It has a history of swallowing into the ocean and killing people,” he said. “I wanted something that was going to be reasonably priced, do-able and to prevent the slides we’ve had for the last 20-30 years.”
However, Cohen argued Alternative X is not “more of the same.”
“I’ve been starting to repeat that as much as I can to the board of supervisors and anyone that’s interested because it is a much more significant repair strategy,” said Cohen. “We have a laundry list of tools and techniques that we are considering at all locations for the entire length of Last Chance Grade. So, there are a lot of things to be determined on exactly what we do with X, but it’s an alternative that has everything under the sun in it.”
Cohen said the key to Alternative X’s success is dewatering the slope using drainage tunnels, also called adits.
“If you can get rid of the water, you can have a significant impact on stabilization,” he said.
Whatever the long-term solution may be, Berkowitz said Crescent City likely missed out on many tourism dollars this summer due to the most recent work closures.
“Having a long-term closure prevents a lot of people, who would come on Highway 101, now picking Highway 5 just because it has been too difficult to get through on 101.”
Right now, CalTrans is predicting construction on a long-term solution to Last Chance to begin around 2030.
Since 1997, landslide repair costs at Last Chance alone have cost more than $100 million. However, a one-year full closure of US 101 caused by a landslide, could mean much worse, including:
- $650 thousand per day in travel costs for commercial and passenger vehicles—$240 million each year
- $450 million in reduced output in Del Norte County
- 3,800 jobs lost
- $145 million in lost wages annually