Debris Flow — San Miguel, Colorado

2020-06-06 · near Telluride, San Miguel, Colorado

Event narrative

Debris left over from the 2019 avalanches became dislodged by heavy rain in the Marshall Creek Basin. A large amount of trees, wood, and other debris from old mining structures travelled down the drainage until it reached the culvert near CR K-69, near the Idarado mine. The water and debris overwhelmed the drainage and began flowing across the roadway. The downstream portion of the roadway began to scour with water and eroded the embankment along the southern shoulder. The road was closed for a few hours.

Wider weather episode

A negatively tilted trough moved through western Colorado on the morning and afternoon of Saturday, June 6th, causing a widespread severe weather event that would become the first derecho to impact the Western Slope in well over a decade. Severe storms produced wind gusts upwards of 60 to 80 mph on average with some gusts topping 80 to 100 mph in some areas due to strong downburst winds. There were multiple reports of uprooted trees, downed power lines, at least one roof was torn off with others damaged, and several houses/cabins and vehicles were damaged by falling trees and/or large hail. Very heavy rain also fell which led to flash flooding in some areas.

View location on OpenStreetMap → (37.9313, -107.7799)

Source: NOAA Storm Events Database, event_id 889190. Narrative written by the NWS forecast office that issued the report.