First signs of spring landslide seen on Howelsen Hill
First signs of spring landslide seen at city's historic ski hill
April 21, 2016
Steamboat Springs — The city's historic ski hill is on the move again.
Howelsen Hill Supervisor Brad Setter reported late last week observing signs of a slope failure on the upper face of the hill that extended to the Alpine Slide.
He said things had become "dramatically worse" on the slope through the course of a day, and the slide threatened to cover a waterbar that was draining water from the surface of the hill.
Interim City Manager Gary Suiter said Thursday it's too early to tell whether the latest movements at the top of Howelsen will impact summer operations.
For now, city staff has installed a perforated pipe to replace the waterbar, which was at risk of being covered by loose earth.
"I don't think there's anything more we can do right now but watch and wait," Suiter said.
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The hill regularly slides in the spring as saturated topsoil loses its grip and falls down the steep slopes.
A slide last year damaged the Alpine Slide and shifted one of the lift towers on the hill.
The city spent $355,000 last year to repair the damage.
The latest movement comes as the city is seeking proposals from geological and hydrological experts to analyze the hill and help develop a scientific approach to stabilize it.
The firm that is hired will conduct field tests and develop a hydro-geologic model of the hill.
At a community meeting in February, a panel of experts discussed the geology of the hill and offered ideas for how to better prevent slides.
There are no silver bullets, the experts said, but there are tools that can make slides less likely.
Kelly Colfer, owner of Western Bionomics, said planting small shrubs and grasses with deeper roots on parts of Howelsen could provide support and help prevent the top soil from sliding when it becomes saturated.
And Brian Len, of Northwest Colorado Consultants, said the best strategy for the city to take on Howelsen is to reduce the amount of water that runs below the surface of the hill and saturates the topsoil.
The city currently has a limited understanding of the overall soil conditions on the upper and lower faces of the ski hill, because it's not known where much of the water that runs below the surface originates.
It is thought increased snowmaking operations on Howelsen have also contributed to the landslides there because of the additional water that flows down the slope in the spring.
Because of this, the city, in recent years, has used a snow cat to remove snow from the hill when the ski area closes.