HAZ-1997-01 Rockfall Hazard Assessment at Booth Falls Condominiums and Proposed Mitigation


This report documents the ongoing CGS assessment of rockfall risk in the area of Booth Creek in Vail, Colorado. Digital PDF download. HAZ-1997-01D


The CGS has assisted the Town of Vail in assessment of the rockfall hazard at Booth Creek since May 1983, when a severe rockfall event occurred there. Since then the town and property owners in Vail Village Filing 12 formed a Geologic Hazard Abatement District (GHAD). The District has mitigated much of the hazard by the construction of a ditch and berm on the slope above the residential area. As far as the Survey knows, the ditch and berm configuration has been 100% effective for rocks that continually fall from the cliffs of the Minturn Formation. On March 26, 1997, another very serious, potentially lethal, rockfall occurred that incurred substantial damage to the Booth Falls Condominiums that exists to the west of the GHAD and outside the protection envelope provided by the ditch and berm. Under the auspices of the Critical Geologic Hazards Response Program and our concerns expressed in earlier involvement, the CGS can assist the Town of Vail in assessment of the hazard that the condominiums bear, options for mitigation for that portion of slope west of the ditch and berm terminus, and design criteria for said mitigation systems. Included in this report are two appendices. Appendix A, Booth Creek Rockfall Hazard Area by Bruce Stover, is a report on the general geology, geomorphology, and the mechanism of rockfall for the Booth Creek site. Appendix B, Rockfall Mitigation, is a short paper on types of rockfall mitigation systems that are available.