Aspen conservation group devotes $100,000 to slope stabilization on Independence Pass |

Aspen conservation group devotes $100,000 to slope stabilization on Independence Pass

Gravity never gives up. Fortunately, neither does Aspen’s Independence Pass Foundation.

IPF is spending $100,000 this fall in its ongoing effort to stabilize the “Top Cut” on Highway 82 near the summit of Independence Pass.

Under bluebird skies and a light breeze Wednesday about a mile west of the 12,095-foot pass, a truck mounted with what looks like a water canon sprayed a foamy green substance onto the steep hillside.

A combination of wood pulp, organic fertilizer and a mix of wildflower and grass seed was applied along with 20,000 gallons of water on about 1 acre by Powell Restoration Inc., the Commerce City contractor hired by IPF.

The goal of the hydroseeding is to get vegetation to grow on the barren hillside, which is susceptible to erosion.

“The geology here is just crap. It’s basically a big pile of gravel,” said Mark Fuller, former executive director of IPF and now a consultant on the restoration project.

The Top Cut was created in 1927 when the modern route of Highway 82 was hacked into the landscape. The hillside above the Top Cut has been slowly unraveling ever since, working further and further upslope.

IPF, founded by the late, legendary Aspen environmentalist Bob Lewis, started work to stabilize the slope in the mid-1990s, often in partnership with the Colorado Department of Transportation.

In one major project, CDOT removed boulders that posed a risk of tumbling off the hillside onto the highway and used them to create a rock retaining wall along about a 400-foot stretch of the Top Cut. Safety is the transportation department’s concern. It leaves the revegetation to IPF.

Fuller and IPF executive director Karin Teague pointed out successful work undertaken on the hillside below the highway at the Top Cut starting in the early 2000s. Mesh netting was placed in some areas to stabilize the slope. Countless schoolkids from the Roaring Fork Valley planted seedlings of subalpine fir and Engelmann spruce over the years. At least 80% have survived and helped create a less barren landscape.

CDOT placed thick metal netting on the slope above the Top Cut to prevent rockfall in 2001. Fuller said the netting used to extend about 6 feet above top of the frayed hillside. Erosion over the years has left the top of the netting a few feet below the eroded area.

“It’s a tough thing to stop until it reaches the angle of repose,” Fuller said.

Teague said: “Gravity just keeps moving on.”

IPF applied for a federal grant to undertake the latest revegetation effort, but it failed to score the funds in what was a competitive 2019 cycle. However, IPF’s board of directors voted to take advantage of a CDOT closure of Highway 82 this fall to undertake the work. CDOT closed the road between 8:30 a.m. and 4:30 p.m. Wednesday. It was scheduled to be closed during daytime on Thursday as well but CDOT determined one lane will remain open all day.

About one quarter-mile from where the IPF revegetation work was underway on Wednesday, workers for CDOT’s contractor used a cherry picker to elevate themselves high up the hillside. They pried loose rocks that posed a threat of natural release, repaired mesh netting damaged by falling rocks and replaced anchors.

“This rockfall mitigation system has aged over time and there is also additional erosion of the slope in this area,” said CDOT spokeswoman Elise Thatcher. The work is routine maintenance, she said.

The project has been underway for about three weeks and could continue for another three. CDOT has budgeted $700,000.

“The final amount depends on how efficiently we can get the work done and whether crews need to bring a helicopter in for part of the work,” Thatcher said in an email.

IPF dipped into its reserve fund and received a large, private donation to undertake its revegetation project. Teague said the $100,000 job is one of the biggest undertaken by IPF in several years.

“It’s a big one, in terms of cost, in terms of preparation,” she said.

Many of the contractors who checked out the job passed on a bid due to the complexity of logistics and challenge of spraying the weed mix so high up the hillside, Teague said.

Chaz Audet, a project manager with Powell, said the project wasn’t all that daunting. He drove the truck along the closed highway for multiple passes while fellow project manager Todd Sutton sprayed the hillside with the seed, fertilizer and mulch mix.

Audet urged patience for the vegetation to appear. It will likely take until spring 2022 for the seed to take because of the high elevation.

Fuller is eager to see the hillside stabilized.

“It used to be we’d come up here in the spring and scrape three feet of tundra off the road,” he said.

(This story was updated to show that one lane will remain open on Independence Pass on Thursday.)