General

Quote: Robert Frost, geohazards expert

Not only sands and gravels Were once more on their travels, But gulping muddy gallons Great boulders off their balance Bumped heads together dully And started down the gully. Whole capes caked off in slices. I felt my standpoint shaken…

Figure 3 -- This development in west Glenwood Springs constructed a rockfall impact wall above their townhomes to protect against both rockfall and mudslides (debris flows). Photo credit: Jon White for the CGS.|Figure 2 -- Several large rocks from the western wall of the Roaring Fork River in Glenwood Springs crashed into the houses below during the early morning causing significant damage
Figure 3 -- This development in west Glenwood Springs constructed a rockfall impact wall above their townhomes to protect against both rockfall and mudslides (debris flows). Photo credit: Jon White for the CGS.|Figure 2 -- Several large rocks from the western wall of the Roaring Fork River in Glenwood Springs crashed into the houses below during the early morning causing significant damage

Hazards

Case Study: Rockfall – Glenwood Springs

The town of Glenwood Springs in west-central Colorado lies at the confluence of the Roaring Fork and Colorado rivers. The town is tightly constrained by the steep river valleys so land-development pressure is causing residential growth to push into rockfall hazard areas. In West Glenwood, on the west side…

By August 2005
By August 2005

Hazards

Case Study: Clear Creek Canyon rockslide

Rockfalls and rock slides are common along transportation corridors in the Rocky Mountains. Clear Creek Canyon just west of Golden is one of the most active rockfall areas in Colorado. The canyon has been cut into Precambrian schists and gneisses by Clear Creek, one of the primary drainages in the…

Avalanche debris in the runout zone taken from a helicopter on the morning after the avalanche occurred
Avalanche debris in the runout zone taken from a helicopter on the morning after the avalanche occurred

Hazards

Case Study: Avalanche – Silver Plume

On March 23, 2003, a large avalanche occurred about one mile west of the Town of Silver Plume. The avalanche brought trees, rock, soil and snow to the valley floor, knocked down overhead utility lines, blocked the I-70 frontage road, damaged the town’s water treatment plant (WTP), and dammed Clear Creek. The dam was breached using explosives before the plant’s electric pump motors were flooded. With damage to the WTP’s chlorine contact tank and building, Silver Plum...

A precarious rock above Manitou Springs started to move in 1995 after a period of wet weather. As an emergency measure
A precarious rock above Manitou Springs started to move in 1995 after a period of wet weather. As an emergency measure

Hazards

Case Study: Rockfall – Manitou Springs

[ED: This report from 1995 was written by Jon White, (Senior Engineering Geologist, Emeritus). It looks at a specific rockfall situation in the central Front Range town. ] Manitou Springs occupies a narrow valley where Fountain Creek emerges from the foothills northeast of Pikes Peak and west of Colorado Springs. The valley slopes are composed of interbedded resistant sandstone and conglomerates (i.e., gravelly sandstone), and weaker mudstones and shale. The outc...