Skagway looks for solution to rockslides that shut down cruise ship berth

The busy cruise ship town of Skagway is looking for a solution to the rockslides that continue to roll down on its largest cruise ship dock. It also hopes to prevent a major rockslide that experts are calling inevitable.

And as winter approaches, the window to execute a workable solution gets smaller and smaller.

The forward berth of the town’s largest cruise ship dock was shut down earlier this summer, about a week before a large slide hit the area. The town has been operating only three out of four berths ever since. That has resulted in the loss of about 125,000 passengers this season.

If the community wants to return to hosting four ships at a time in 2023, it has less than seven months to fix the problem.

Geotechnical engineering firm Shannon and Wilson made its initial pitch to address the slides at the borough assembly’s Sept. 1 meeting. Anchorage-based Geotechnical Engineer, Kyle Brennan’s tone was hopeful but realistic. “It’s a complicated issue, and time is not helping,” he said.

He said there are about 40,000 to 60,000 cubic yards of rock that need to be moved off the mountainside to prevent major and minor rockslides. The process would involve hauling equipment to the top, digging out the rock, moving it up over the top of the hillside and dumping the material out of the way in a safe spot, then repeating the process as the equipment moves down the slope until it is completed.

Brennan said there are two problems: One is the ongoing smaller rockslides, of which there have been several over the past few weeks. The other is the large unstable mass at the top of the slope that he said will eventually release and destroy the area below the slide zone — and potentially much more if left untouched.

“What we’re trying to do is twofold. One, remove this very large hazard. But also, by doing so, we should greatly reduce the amount of rock fall that’s produced along the slope because we no longer have that moving rock mass,” Brennan said. “The rock fall hazard will never go away completely because you have a steep rock slope, and steep rock slopes over time generate rock fall occasionally, but the frequency of those rockfalls should be reduced dramatically.”

Brennan said his firm will have preliminary design plans for mitigation completed soon, which would allow filing for permits and grants. But even if those plans are ready by mid-September, it’s not likely that permits would be approved before mid-winter.

“If we can get that contractor on early, you know, there are certain components of the project that maybe they can start that don’t really rely so much on the permitting: staging equipment, establishing access, maybe doing some work to prep the upslope disposal site for the rock,” he said.

That may include improving road access to Lower Dewey Lake to get large excavators and dump trucks to the construction site.

Assemblymember Orion Hanson suggested progress needs to start on those developments immediately. “Any suggestion of a helicopter getting a 70,000-(pound) excavator up that mountain seems completely impossible to me,” Hanson said.

And without helicopter-assisted access, road work would need to begin before the winter freeze.

 

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