Conducted a debris flow hazard assessment for a proposed residential subdivision and golf course in Carbondale, Colorado. Developed a debris flow model based on evidence from prehistoric debris flows observed in alluvial fan test pits and evidence from a large historic (1959) debris flood/flow. Provided recommendations for hazard avoidance and reduction.

Pleasant View City required that geologic hazards be addressed prior to development of an approximately 200 acre hillside north of Ogden, Utah. The site was located near the apex of an active alluvial fan at the mouth of an intermittent stream drainage. City ordinance required that the runoff from the 10- year storm be addressed. An analysis was performed on the drainage basin to determine the channel size requirements for both the 10 and 100 year storm and associated debris flow events. A probability risk assessment was also provided to help characterize the large-scale debris-flow return interval and relative risk to the site.

Evaluated the debris flow potential and provided recommendations for emergency watershed protection following the September 1988 Affleck Park wild fire which burned over 5600 acres (22.7 km2) across several drainages in "suburbanized" Emigration Canyon, Utah. Analysis of the burned drainage indicated a 700 percent increase in potential sediment yield over the pre-fire conditions. Based on the recommendations of this study an emergency watershed restoration project was initiated to help mitigate erosion hazards. Erosion control structures consisting of 24 gabion baskets and 84 wire silt fences were installed across the upland slopes and a debris basin was constructed at the base of one major intermittent channel. The following spring a localized, intense rain storm (estimated to be in excess of the 100 year event) triggered a large mobilization of sediment across a portion of the not-yet-revegetated burn area. Silt fences and gabions helped collect sediment and reduce peak debris flow volumes (although the force of the flows toppled several of the gabion structures). Two homes near the base of one drainage suffered some mud-related basement damage. The debris-basin protected drainage was not impacted by the localized storm. Estimates of the debris generated closely matched the predicted sediment yield for a post-fire event.

A 6-lot Planned Unit Development (PUD) located within a steep drainage on the northern slope of Mt. Olympus, near Salt Lake City, Utah may be subject to periodic storm flooding and debris flow deposition. The purpose of this study was to determine the risk to the proposed homes from these hazards and to quantify the flow rates for three scenarios: 1) runoff confined to pre-existing drainage channels, 2) runoff as pure sheet flow, and 3) a combination of sheetflow and channel flow. Runoff rates were calculated using the SCS runoff model for 24 hour duration storms with return periods of 2, 10, and 24 years and precipitation of 45, 65, and 94mm respectively. Recommendations were provided for locating the building pads and grading to minimize the risks from storm water and debris.