For the first time, the Colorado Geological Survey has compiled a map highlighting areas across the state prone to sinkholes.
A scan of the map shows the largest ground formation hazards near Eagle County and Glenwood Springs. A report accompanying the map shows pictures of agricultural land, a golf course—even part of Colorado Mountain College’s Roaring Fork campus with large ground depressions.
But Northern Colorado—particularly near Horsetooth Reservoir and Carter Lake in Larimer County—have geologic conditions that have lead to ground depressions. Larimer County’s Red Mountain Open Space near Table Mountain has also seen sink holes in recent years.
“If you’re going to be doing any kind of construction in that Lykins Strike Valley, the dissolution and subsidence of the ground surface should be a consideration in whatever you’re proposing,” says Jonathan White, senior engineering geologist with the Colorado Geological Survey.
At play is so-called “evaporate bedrock,” which starts dissolving–and causing ground depressions–when it’s exposed to fresh water.
White says that the map and an accompanying report provide a bird eye’s view of these geologic risks statewide. But for site-specific problems, the Geological Survey is urging landowners and planners to commission individual hazard studies.