U.S. Forest Service officials said they will review information from a new mapping technique that shows landslides have run through the middle of the land where an expansion of the Mt. Ashland Ski Area is planned.

U.S. Forest Service officials said they will review information from a new mapping technique that shows landslides have run through the middle of the land where an expansion of the Mt. Ashland Ski Area is planned.

However, the information may not be entirely new to officials. Prior Forest Service mapping shows a sensitive riparian area with the second highest level of landslide risk running through the center of the expansion land.

Planned ski runs and a new chairlift were designed to mostly skirt the sensitive area by passing on either side of that land.

But some portions of runs and the chairlift cut through the riparian-landslide zone.

A total of 14.82 acres in riparian-landslide areas would be cleared. The expansion calls for 71 acres of new ski runs, according to Forest Service documents.

Earlier this year, the Oregon Department of Geology and Mineral Industries mapped landslide hazards along Interstate 5 using a new aerial laser technique that can see through vegetation and reveal highly detailed images of land forms. The technique is known as LiDAR, for light detection and ranging. LiDAR mapping revealed past landslide debris flows running through the center of the expansion zone.

The LiDAR debris zone starts in the existing ski area at The Bowl, a steep, bowl-like run for advanced skiers near the mountain's summit. The landslide debris zone continues downhill into the expansion area, roughly following the middle branch of Ashland Creek.

The Forest Service's mapped riparian-landslide area follows a similar path as the landslide debris flow shown by LiDAR.

Debris flows are chaotic mixes of soil and rock that should be considered at risk of further slope movement, according to the DOGAMI.

Bill Hicks, an engineering geologist who lives in Ashland, uses LiDAR professionally to find geologic faults, which are promising areas for wells. He also has studied flood-related landslides in the Ashland Watershed, home to the ski area. Hicks said he believes that by not using LiDAR, the Forest Service didn't use the best available science. Hicks said the new LiDAR map of the expansion area that shows landslide deposits reveals that the expansion area has too many problems to be developed with confidence.

"That basin is so difficult and has so many issues with it that I would never want to work on putting that expansion there," said Hicks, noting that he now opposes the ski area expansion.

With highly erosive soil and steep slopes on the mountain, Hicks said a small landslide can grow up to 100 times its original size as it slices downward through the Ashland Watershed.

Longtime expansion opponent and former Ashland City Councilor Eric Navickas said the LiDAR mapping reinforces his fears that the expansion is planned on land that is at high risk for landslides.

"The historical evidence shows that even without human disturbance, there was landslide activity within those areas," he said.

In response to residents' concerns about the new LiDAR mapping, Scott Conroy, forest supervisor for the Rogue River-Siskiyou National Forest, said in a letter that agency specialists are currently reviewing the new data.

He said Forest Service policy requires him to review the information carefully to determine its importance.

Conroy added, "Based on years of analysis by Forest Service employees and contractors, I believe the expansion would not measurably affect water quality or quantity in the Ashland Watershed."

Siskiyou Mountains District Ranger Donna Mickley said this week that the review of the LiDAR mapping will take about six weeks to two months. She said the Forest Service will put its response in writing so that everyone can see it.

Mickley said the Forest Service would not have approved the ski area expansion if officials thought it would be detrimental to the Ashland Watershed, source of Ashland's water supply.

"We cannot see how there will be any kind of catastrophic effects," she said.

The Mt. Ashland Association, which runs the ski area, has forged an agreement with the city of Ashland that no additional sediment from the expansion will flow into Reeder Reservoir above levels that currently flow in. The reservoir is fed by Ashland Creek and stores the city's water high above Lithia Park.

Siskiyou Mountains Ranger District Recreation Specialist Steve Johnson, who has spent years working on expansion analyses, said the Forest Service is already aware of landslide hazard zones in the watershed, including in the expansion area.

He said soil scientists and geologists crisscrossed the expansion area, creating site-specific maps of the land.

"LiDAR does not replace a person looking on the ground. LiDAR is not the answer to everything. It's a wonderful tool that has been used heavily in AFR," Johnson said, referring to the Forest Service's Ashland Forest Resiliency Stewardship Project that is thinning fire-prone trees and brush in the watershed. "I believe we will use it if and when the implementation of the expansion occurs."

While the Forest Service has approved the expansion, the agency must go back to court to get an injunction lifted. The Forest Service could return to court later this fall or winter.

Johnson said there are numerous safeguards to minimize impacts to the land if the expansion moves forward.

Some logged trees will be removed by helicopter, but other felled trees will be allowed to remain on the ground — along with slash, brush and low-growing vegetation — to minimize bare soil and erosion, according to Forest Service documents.

Trees in and near wetlands will be cut only during the winter so that they will fall on snow, creating a light impact on the ground, Johnson said.

He said a "spider" excavator that walks on legs instead of using tracks also will be used.

A wetlands bridge at the bottom of the expansion area will minimize impacts as well, and a Forest Service hydrologist or geologist will provide oversight for that crossing work, Johnson said.

Straw bales or other anti-erosion devices will be used. Ground that was disturbed for chairlift tower excavation will be covered with rocks or chips to prevent erosion and vegetation will be re-established, he said.

Mt. Ashland Association board members said they were bothered that expansion opponents did not inform them directly of the new LiDAR mapping, or tell them firsthand about a video they made on the issue.

Opponents shot video of an August panel discussion in which four scientists, including Hicks, discussed the LiDAR mapping and landslide risks.

An edited 22-minute video of that panel discussion is posted on YouTube under the heading "Panel on the Mt. Ashland Ski Expansion."

Former Ashland Mayor Alan DeBoer, an adviser to the Mt. Ashland Association's board, said the video is one-sided. He said he believes past Forest Service studies that show the watershed will not be damaged by an expansion.

"None of us would do anything to harm the watershed. What we need is communication," DeBoer said.

Rogue Group Sierra Club member Julie Norman, who has spoken out about the LiDAR mapping, said she would like to see an expansion that doesn't intrude on the landslide zone revealed by LiDAR along Ashland Creek's middle branch.

"I'm hoping for a renewed discussion of other designs for expanding the ski area, while avoiding the landslide debris, carved off rocks and loose soil in the middle branch that have been steadily sliding downhill from Mt. Ashland's glacial cirque for 10,000 years," Norman said.

Staff reporter Vickie Aldous can be reached at 541-479-8199 or vlaldous@yahoo.com.